FN Thomson Reuters Web of Science™
VR 1.0
PT J
AU Palmeri, P
Quinet, P
Mendoza, C
Bautista, MA
Garcia, J
Witthoeft, MC
Kallman, TR
AF Palmeri, P.
Quinet, P.
Mendoza, C.
Bautista, M. A.
Garcia, J.
Witthoeft, M. C.
Kallman, T. R.
TI RADIATIVE AND AUGER DECAY DATA FOR MODELING NICKEL K LINES
SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
LA English
DT Article
DE atomic data; atomic processes; line: formation; X-rays: general
ID RAY-INTENSITY RATIOS; TRANSITION-PROBABILITY RATIOS; XMM-NEWTON; VACANCY
STATES; ABSORPTION FEATURES; IGR J16318-4848; ENERGY-LEVELS; VELA X-1;
FE-XVII; EMISSION
AB Radiative and Auger decay data have been calculated for modeling the K lines in ions of the nickel isonuclear sequence, from Ni+ up to Ni27+. Level energies, transition wavelengths, radiative transition probabilities, and radiative and Auger widths have been determined using Cowan's Hartree-Fock with relativistic corrections (HFR) method. Auger widths for the third-row ions (Ni+-Ni10+) have been computed using single-configuration average (SCA) compact formulae. Results are compared with data sets computed with the AUTOSTRUCTURE and MCDF atomic structure codes and with available experimental and theoretical values, mainly in highly ionized ions and in the solid state.
C1 [Palmeri, P.; Quinet, P.] Univ Mons, B-7000 Mons, Belgium.
[Quinet, P.] Univ Liege, IPNAS, B-4000 Liege, Belgium.
[Mendoza, C.] IVIC, Ctr Fis, Caracas 1020A, Venezuela.
[Bautista, M. A.] Virginia Polytech Inst & State Univ, Dept Phys, Blacksburg, VA 24061 USA.
[Garcia, J.] Catholic Univ Amer, Dept Phys, IACS, Washington, DC 20064 USA.
[Witthoeft, M. C.; Kallman, T. R.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
RP Palmeri, P (reprint author), Univ Mons, B-7000 Mons, Belgium.
EM palmeri@umh.ac.be; quinet@umh.ac.be; claudio@ivic.ve; bautista@vt.edu;
javier@milkyway.gsfc.nasa.gov; michael.c.witthoeft@nasa.gov;
timothy.r.kallman@nasa.gov
FU NASA Astronomy and Physics Research and Analysis Program
FX This work was funded in part by the NASA Astronomy and Physics Research
and Analysis Program. P. P. and P. Q. are Research Associates of the
Belgian FRS-FNRS.
NR 57
TC 15
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U1 0
U2 5
PU IOP PUBLISHING LTD
PI BRISTOL
PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND
SN 0067-0049
EI 1538-4365
J9 ASTROPHYS J SUPPL S
JI Astrophys. J. Suppl. Ser.
PD DEC
PY 2008
VL 179
IS 2
BP 542
EP 552
DI 10.1086/591965
PG 11
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 400IW
UT WOS:000262862300012
ER
PT J
AU Holzmann, GJ
Joshi, R
Groce, A
AF Holzmann, Gerard J.
Joshi, Rajeev
Groce, Alex
TI Model driven code checking
SO AUTOMATED SOFTWARE ENGINEERING
LA English
DT Article
DE Software verification; Logic model checking; Spin model checker;
Embedded C code
AB Model checkers were originally developed to support the formal verification of high-level design models of distributed system designs. Over the years, they have become unmatched in precision and performance in this domain. Research in model checking has meanwhile moved towards methods that allow us to reason also about implementation level artifacts (e.g., software code) directly, instead of hand-crafted representations of those artifacts. This does not mean that there is no longer a place for the use of high-level models, but it does mean that such models are used in a different way today. In the approach that we describe here, high-level models are used to represent the environment for which the code is to be verified, but not the application itself. The code of the application is now executed as is by the model checker, while using powerful forms of abstraction on-the-fly to build the abstract state space that guides the verification process. This model-driven code checking method allows us to verify implementation level code efficiently for high-level safety and liveness properties. In this paper, we give an overview of the methodology that supports this new paradigm of code verification.
C1 [Holzmann, Gerard J.; Joshi, Rajeev; Groce, Alex] CALTECH, Jet Prop Lab, Lab Reliable Software, Pasadena, CA 91109 USA.
RP Holzmann, GJ (reprint author), CALTECH, Jet Prop Lab, Lab Reliable Software, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM gerard@spinroot.com
FU NASA's Exploration Technology Development Program (ETDP)
FX The research described in this paper was carried out at the Jet
Propulsion Laboratory, California Institute of Technology, under a
contract with the National Aeronautics and Space Administration. The
work was supported in part by NASA's Exploration Technology Development
Program (ETDP) on Reliable Software Engineering.
NR 9
TC 12
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U1 0
U2 0
PU SPRINGER
PI NEW YORK
PA 233 SPRING ST, NEW YORK, NY 10013 USA
SN 0928-8910
J9 AUTOMAT SOFTW ENG
JI Automat. Softw. Eng.
PD DEC
PY 2008
VL 15
IS 3-4
BP 283
EP 297
DI 10.1007/s10515-008-0033-9
PG 15
WC Computer Science, Software Engineering
SC Computer Science
GA 367FV
UT WOS:000260538800004
ER
PT J
AU Mishchenko, MI
Travis, LD
AF Mishchenko, Michael I.
Travis, Larry D.
TI GUSTAV MIE AND THE EVOLVING DISCIPLINE OF ELECTROMAGNETIC SCATTERING BY
PARTICLES
SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY
LA English
DT Article
ID POLARIZATION; PHOTON; MATTER
AB The year 2008 marks the centenary of the seminal paper by Gustav Mie on electromagnetic scattering by homogeneous spherical particles. Having been cited in almost 4,000 journal articles since 1955 (according to the Science Citation Index Expanded database), Mie's paper has been among the more influential scientific publications of the twentieth century. It has affected profoundly the development of a great variety of natural science disciplines including atmospheric radiation, meteorological optics, remote sensing, aerosol physics, astrophysics, and biomedical optics. Mie's paper represented a fundamental advancement over the earlier publications by Ludvig Lorenz in that it was explicitly based on the Maxwell equations, gave the final solution in a convenient form suitable for practical computations, and imparted physical reality to the abstract concept of electromagnetic scattering. The Mie solution anticipated such general concepts as far-field scattering and the Sommerfeld-Silver-Muller boundary conditions at infinity as well as paved the way to such important extensions as the separation of variables method for spheroids and the T-matrix method. Key ingredients of the Mie theory are quite prominent in the superposition T-matrix method for clusters of particles and even in the recent microphysical derivation of the radiative transfer equation. Among the most illustrative uses of the Mie solution have been the explanation of the spectacular optical displays caused by cloud and rain droplets, the identification of sulfuric acid particles in the atmosphere of Venus from Earth-based polarimetry, and optical particle characterization based on measurements of morphology-dependent resonances. Yet it is clear that the full practical potential of the Mic theory is still to be revealed.(Page 1853)
C1 [Mishchenko, Michael I.; Travis, Larry D.] NASA, Goddard Inst Space Studies, New York, NY 10025 USA.
RP Mishchenko, MI (reprint author), NASA, Goddard Inst Space Studies, 2880 Broadway, New York, NY 10025 USA.
EM mmishchenko@giss.nasa.gov
RI Mishchenko, Michael/D-4426-2012
FU NASA Radiation Sciences Program; NASA Glory Mission project
FX We thank Helmut Domke, Joop Hovenier, Michael Kahnert, Wolfram Hergert,
and two anonymous reviewers for helpful comments on a preliminary
version of this paper. We thank Jean-Claude Auger and Daniel Mackowski
for their generous help with Fig. 2. Figures 3 and 4 are reproduced with
kind permissions from Philip Laven and Ludmila Zenkova. We thank P.
Lilienfeld for the permission to reproduce the photograph of Gustav Mie
and acknowledge fellow NASA scientists from the Jet Propulsion
Laboratory for posting the Mars Global Surveyor image of the Mie Crater
on their public Web site. This research was funded by the NASA Radiation
Sciences Program managed by Hal Maring and by the NASA Glory Mission
project.
NR 46
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U1 0
U2 11
PU AMER METEOROLOGICAL SOC
PI BOSTON
PA 45 BEACON ST, BOSTON, MA 02108-3693 USA
SN 0003-0007
J9 B AM METEOROL SOC
JI Bull. Amer. Meteorol. Soc.
PD DEC
PY 2008
VL 89
IS 12
BP 1853
EP +
DI 10.1175/2008BAMS2632.1
PG 11
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 389KH
UT WOS:000262090800006
ER
PT J
AU Sperber, KR
Waliser, DE
AF Sperber, Kenneth R.
Waliser, Duane E.
TI NEW APPROACHES TO UNDERSTANDING, SIMULATING, AND FORECASTING THE
MADDEN-JULIAN OSCILLATION
SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY
LA English
DT Editorial Material
C1 [Waliser, Duane E.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[Sperber, Kenneth R.] Lawrence Livermore Natl Lab, Livermore, CA USA.
RP Waliser, DE (reprint author), CALTECH, Jet Prop Lab, MS 183-505,4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM duane.waliser@jpl.nasa.gov
RI Sperber, Kenneth/H-2333-2012
NR 0
TC 16
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U1 0
U2 4
PU AMER METEOROLOGICAL SOC
PI BOSTON
PA 45 BEACON ST, BOSTON, MA 02108-3693 USA
SN 0003-0007
J9 B AM METEOROL SOC
JI Bull. Amer. Meteorol. Soc.
PD DEC
PY 2008
VL 89
IS 12
BP 1917
EP 1920
DI 10.1175/2008BAMS2700.1
PG 4
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 389KH
UT WOS:000262090800012
ER
PT J
AU Yong, A
Hough, SE
Abrams, MJ
Cox, HM
Wills, CJ
Simila, GW
AF Yong, Alan
Hough, Susan E.
Abrams, Michael J.
Cox, Helen M.
Wills, Christopher J.
Simila, Gerry W.
TI Site Characterization Using Integrated Imaging Analysis Methods on
Satellite Data of the Islamabad, Pakistan, Region
SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA
LA English
DT Article
ID SPACEBORNE THERMAL EMISSION; REFLECTION RADIOMETER ASTER; CALIFORNIA;
GEOLOGY; MAP; MOUNTAINS; IMAGES; ZONE
AB We develop an integrated digital imaging analysis approach to produce a first-approximation site characterization map for Islamabad, Pakistan, based on remote-sensing data. We apply both pixel-based and object-oriented digital imaging analysis methods to characterize detailed (1: 50; 000) geomorphology and geology from Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) satellite imagery. We use stereo-correlated relative digital elevation models (rDEMs) derived from ASTER data, as well as spectra in the visible near-infrared (VNIR) to thermal infrared (TIR) domains. The resulting geomorphic units in the study area are classified as mountain (including the Margala Hills and the Khairi Murat Ridge), piedmont, and basin terrain units. The local geologic units are classified as limestone in the Margala Hills and the Khairi Murat Ridge and sandstone rock types for the piedmonts and basins. Shear-wave velocities for these units are assigned in ranges based on established correlations in California. These ranges include V(s)30-values to be greater than 500 m/sec for mountain units, 200-600 m/sec for piedmont units, and less than 300 m/sec for basin units. While the resulting map provides the basis for incorporating site response in an assessment of seismic hazard for Islamabad, it also demonstrates the potential use of remote-sensing data for site characterization in regions where only limited conventional mapping has been done.
C1 [Yong, Alan; Hough, Susan E.] US Geol Survey, Dept Interior, Earthquake Hazards Team, Pasadena, CA 91106 USA.
[Abrams, Michael J.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[Cox, Helen M.; Simila, Gerry W.] Calif State Univ Northridge, Northridge, CA 91330 USA.
[Wills, Christopher J.] Calif Geol Survey, Sacramento, CA 95814 USA.
RP Yong, A (reprint author), US Geol Survey, Dept Interior, Earthquake Hazards Team, 525 S Wilson Ave, Pasadena, CA 91106 USA.
FU U. S. Geological Survey Working Capital Fund; California State
University; Northridge (CSUN) CATALYST program; National Science
Foundation-Geoscience [NSF-GEO-0119936, NSF-GEO-0503609]
FX We greatly appreciate the helpful review comments by Robert S. Dollar,
Karen R. Felzer, and Martin Chapman, in addition to early discussions
with Kenneth W. Hudnut and Edward H. Field. We also greatly appreciate
technical guidance from David Hulslander and Keith Nicholson of ITT
Visual Information Solutions and Matthias Stolz and John Parker of
Definiens AG. David Coss Y. Leon contributed to the preparation of the
maps for publication. Work done by Michael J. Abrams was performed at
the Jet Propulsion Laboratory/California Institute of Technology, under
a contract to the National Aeronautics and Space Administration. We
thank Linda Gundersen for partial support through the U. S. Geological
Survey Working Capital Fund. Partial support was also provided by the
California State University, Northridge (CSUN) CATALYST program, funded
by National Science Foundation-Geoscience (Number NSF-GEO-0119936
[2001-2005] and Number 0503609 [2005-2009]).
NR 60
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PU SEISMOLOGICAL SOC AMER
PI EL CERRITO
PA PLAZA PROFESSIONAL BLDG, SUITE 201, EL CERRITO, CA 94530 USA
SN 0037-1106
J9 B SEISMOL SOC AM
JI Bull. Seismol. Soc. Amer.
PD DEC 1
PY 2008
VL 98
IS 6
BP 2679
EP 2693
DI 10.1785/0120080930
PG 15
WC Geochemistry & Geophysics
SC Geochemistry & Geophysics
GA 376KW
UT WOS:000261183500008
ER
PT J
AU Wu, ZH
Schneider, EK
Kirtman, BP
Sarachik, ES
Huang, NE
Tucker, CJ
AF Wu, Zhaohua
Schneider, Edwin K.
Kirtman, Ben P.
Sarachik, E. S.
Huang, Norden E.
Tucker, Compton J.
TI The modulated annual cycle: an alternative reference frame for climate
anomalies
SO CLIMATE DYNAMICS
LA English
DT Article
DE Modulated annual cycle; Traditional annual cycle; Extrinsic annual
cycle; Intrinsic annual cycle; Climate anomaly; Alternative reference
frame; Reemergence; ENSO phase locking to annual cycle; Decadal climate
variability of winter (summer) temperature; Nonlinear non-stationary
time series; Empirical mode decomposition; Ensemble empirical mode
decomposition
ID EMPIRICAL MODE DECOMPOSITION; NINO SOUTHERN-OSCILLATION; SEA-SURFACE
TEMPERATURE; NONSTATIONARY TIME-SERIES; OCEAN-ATMOSPHERE MODEL; EL-NINO;
SEASONAL CYCLE; NORTH-ATLANTIC; SST ANOMALIES; PACIFIC-OCEAN
AB In climate science, an anomaly is the deviation of a quantity from its annual cycle. There are many ways to define annual cycle. Traditionally, this annual cycle is taken to be an exact repeat of itself year after year. This stationary annual cycle may not reflect well the intrinsic nonlinearity of the climate system, especially under external forcing. In this paper, we re-examine the reference frame for anomalies by re-examining the annual cycle. We propose an alternative reference frame for climate anomalies, the modulated annual cycle (MAC) that allows the annual cycle to change from year to year, for defining anomalies. In order for this alternative reference frame to be useful, we need to be able to define the instantaneous annual cycle: we therefore also introduce a new method to extract the MAC from climatic data. In the presence of a MAC, modulated in both amplitude and frequency, we can then define an alternative version of an anomaly, this time with respect to the instantaneous MAC rather than a permanent and unchanging AC. Based on this alternative definition of anomalies, we re-examine some familiar physical processes: in particular SST re-emergence and ENSO phase locking to the annual cycle. We find that the re-emergence mechanism may be alternatively interpreted as an explanation of the change of the annual cycle instead of an explanation of the interannual to interdecadal persistence of SST anomalies. We also find that the ENSO phase locking can largely be attributed to the residual annual cycle (the difference of the MAC and the corresponding traditional annual cycle) contained in the traditional anomaly, and, therefore, can be alternatively interpreted as a part of the annual cycle phase locked to the annual cycle itself. In addition to the examples of reinterpretation of physics of well known climate phenomena, we also present an example of the implications of using a MAC against which to define anomalies. We show that using MAC as a reference framework for anomaly can bypass the difficulty brought by concepts such as "decadal variability of summer (or winter) climate" for understanding the low-frequency variability of the climate system. The concept of an amplitude and frequency modulated annual cycle, a method to extract it, and its implications for the interpretation of physical processes, all may contribute potentially to a more consistent and fruitful way of examining past and future climate variability and change.
C1 [Wu, Zhaohua] Ctr Ocean Land Atmospher Stuides, Calverton, MD 20705 USA.
[Schneider, Edwin K.] George Mason Univ, Dept Climate Dynam, Fairfax, VA 22030 USA.
[Kirtman, Ben P.] Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, Coral Gables, FL 33124 USA.
[Sarachik, E. S.] Univ Washington, Dept Atmospher Sci, Seattle, WA 98195 USA.
[Huang, Norden E.] Natl Cent Univ, Res Ctr Data Anal, Chungli 32054, Taiwan.
[Tucker, Compton J.] NASA, Hydrospher & Biospher Sci Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
RP Wu, ZH (reprint author), Ctr Ocean Land Atmospher Stuides, 4041 Powder Mill Rd,Suite 302, Calverton, MD 20705 USA.
EM zhwu@cola.iges.org
RI Wu, Zhaohua/N-7102-2013;
OI Wu, Zhaohua/0000-0003-1660-0724
FU National Science Foundation of USA [ATM-0342104, ATM-0653123]; Taiwan
Semiconductor Manufacturing Company. Ltd.; National Research Council,
Taiwan, ROC [95-2119-M-008-031-MY3]
FX ZW is grateful for two anonymous reviewers for their insightful comments
and suggestions to improve the paper. ZW is also grateful for Drs. T.
DelSole and V. Krishnamurthy of COLA for their careful reading of the
early version of this manuscript and their suggestions of correction. ZW
is supported by National Science Foundation of USA under grants
ATM-0342104 and ATM-0653123. NEH is supported in part by a Chair at NCU
endowed by Taiwan Semiconductor Manufacturing Company. Ltd., and a
grant, NSC 95-2119-M-008-031-MY3, from the National Research Council,
Taiwan, ROC.
NR 59
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U1 2
U2 23
PU SPRINGER
PI NEW YORK
PA 233 SPRING ST, NEW YORK, NY 10013 USA
SN 0930-7575
J9 CLIM DYNAM
JI Clim. Dyn.
PD DEC
PY 2008
VL 31
IS 7-8
BP 823
EP 841
DI 10.1007/s00382-008-0437-z
PG 19
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 364XZ
UT WOS:000260370300006
ER
PT J
AU Higginbotham, AL
Moloney, PG
Waid, MC
Duque, JG
Kittrell, C
Schmidt, HK
Stephenson, JJ
Arepalli, S
Yowell, LL
Tour, JM
AF Higginbotham, Amanda L.
Moloney, Padraig G.
Waid, Michael C.
Duque, Juan G.
Kittrell, Carter
Schmidt, Howard K.
Stephenson, Jason J.
Arepalli, Sivaram
Yowell, Leonard L.
Tour, James M.
TI Carbon nanotube composite curing through absorption of microwave
radiation
SO COMPOSITES SCIENCE AND TECHNOLOGY
LA English
DT Article
DE Ceramic-matrix composites; Carbon nanotubes; Curing; Microwave
Processing
ID SINGLE; PHASE; ALLYLHYDRIDOPOLYCARBOSILANE; DECOMPOSITION; SPECTROSCOPY;
FABRICATION; PRECURSOR; GROWTH
AB The microwave absorbing properties and subsequent heating of carbon nanotubes can be used to rapidly cure ceramic composites. With less than 1 wt% carbon nanotube additives and 30-40 W of directed microwave power (2.45 GHz), bulk composite samples reach temperatures above 500 degrees C within 1 min. Multiwalled carbon nanotubes (MWNTs), functionalized MWNTs (f-MWNTs), raw single-walled carbon nanotubes (r-SWNTs) and purified SWNTs (p-SWNTs) were all used to produce composites in Starfire (R) SMP-10 silicon carbide pre-ceramic. MWNTs loaded at 0.75 wt% in SMP-10 consistently displayed the fastest rate of heating (similar to 500 degrees C in 10 s) and highest temperatures (1150 degrees C in 7 min). The degree of composite curing was monitored by TGA. The nanotube/matrix dispersion and integrity was imaged using optical microscopy, TEM and SEM, and Raman spectroscopy was used to determine the state of the nanotubes after exposure to microwave radiation. (c) 2008 Elsevier Ltd. All rights reserved.
C1 [Higginbotham, Amanda L.; Duque, Juan G.; Kittrell, Carter; Schmidt, Howard K.; Stephenson, Jason J.; Tour, James M.] Rice Univ, Dept Chem, Dept Mech Engn & Mat Sci, Dept Chem & Biomol Engn, Houston, TX 77005 USA.
[Higginbotham, Amanda L.; Duque, Juan G.; Kittrell, Carter; Schmidt, Howard K.; Stephenson, Jason J.; Tour, James M.] Rice Univ, Smalley Inst Nanoscale Sci & Technol, Houston, TX 77005 USA.
[Moloney, Padraig G.; Waid, Michael C.; Arepalli, Sivaram; Yowell, Leonard L.] NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA.
RP Tour, JM (reprint author), Rice Univ, Dept Chem, Dept Mech Engn & Mat Sci, Dept Chem & Biomol Engn, MS-222,6100 Main St, Houston, TX 77005 USA.
EM tour@rice.edu
RI Duque, Juan/G-2657-2010; Arepalli, Sivaram/A-5372-2010;
OI Tour, James/0000-0002-8479-9328
FU NASA; TIIMS Director's Discretionary Fund [NNJ05H105 C]
FX Financial support was provided by NASA (URETI TIIMS at Texas A&M, TIIMS
Director's Discretionary Fund, and contract #NNJ05H105 C) and the Welch
Foundation (C-1668). Thanks are also due to Mike Fowler for providing
guidance and information for material selection of this work. We thank
Bussan Nanotech and M. Endo for providing MWNT samples.
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PU ELSEVIER SCI LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND
SN 0266-3538
EI 1879-1050
J9 COMPOS SCI TECHNOL
JI Compos. Sci. Technol.
PD DEC
PY 2008
VL 68
IS 15-16
BP 3087
EP 3092
DI 10.1016/j.compscitech.2008.07.004
PG 6
WC Materials Science, Composites
SC Materials Science
GA 383JR
UT WOS:000261670400004
ER
PT J
AU Morscher, GN
Ojard, G
Miller, R
Gowayed, Y
Santhosh, U
Ahmad, J
John, R
AF Morscher, Gregory N.
Ojard, Greg
Miller, Robert
Gowayed, Yasser
Santhosh, Unni
Ahmad, Jalees
John, Reji
TI Tensile creep and fatigue of Sylramic-iBN melt-infiltrated SiC matrix
composites: Retained properties, damage development, and failure
mechanisms
SO COMPOSITES SCIENCE AND TECHNOLOGY
LA English
DT Article
DE Ceramic matrix composites; Creep; Fatigue; Matrix cracking; Acoustic
emission
ID SIC/SIC COMPOSITES; STRESS; TEMPERATURE; BEHAVIOR
AB An understanding of the elevated temperature tensile creep, fatigue, rupture, and retained properties of ceramic matrix composites (CMC) envisioned for use in gas turbine engine applications is essential for component design and life-prediction. In order to quantify the effect of stress, time, temperature, and oxidation for a state-of-the-art composite system, a wide variety of tensile creep, dwell fatigue, and cyclic fatigue experiments were performed in air at 1204 degrees C for the SiC/SiC CIVIC system consisting of Sylramic-iBN SiC fibers, BN fiber interphase coating, and slurry-cast melt-infiltrated (MI) SiC-based matrix. Tests were either taken to failure or interrupted. Interrupted tests were then mechanically tested at room temperature to determine the residual properties. The retained properties of most of the composites subjected to tensile creep or fatigue were usually within 20% of the as-produced strength and 10% of the as-produced elastic modulus. It was observed that during creep, residual stresses in the composite are altered to some extent which results in an increased compressive stress in the matrix upon cooling and a subsequent increased stress required to form matrix cracks. Microscopy of polished sections and the fracture surfaces of specimens which failed during stressed-oxidation or after the room-temperature retained property test was performed on some of the specimens in order to quantify the nature and extent of damage accumulation that occurred during the test. It was discovered that the distribution of stress-dependent matrix cracking at 1204 degrees C was similar to the as-produced composites at room temperature; however, matrix crack growth occurred over time and typically did not appear to propagate through-the-thickness except at the final failure crack. Failure of the composites was due to either oxidation-induced unbridged crack growth, which dominated the higher stress regime (>= 179 MPa) or controlled by degradation of the fibers, probably caused by intrinsic creep-induced flaw growth of the fibers or internal attack of the fibers via Si diffusion through the CVI SiC and/or microcracks at the lower stress regime (<= 165 MPa). (C) 2008 Elsevier Ltd. All rights reserved.
C1 [Morscher, Gregory N.] NASA, Glenn Res Ctr, Ohio Aerosp Inst, Cleveland, OH 44135 USA.
[John, Reji] USAF, Mat & Mfg Directorate, Res Lab, RXLMN, Wright Patterson AFB, OH 45433 USA.
[Ojard, Greg; Miller, Robert] Pratt & Whitney, E Hartford, CT USA.
[Gowayed, Yasser] Auburn Univ, Auburn, AL 36849 USA.
[Santhosh, Unni; Ahmad, Jalees] Res Applicat Inc, San Diego, CA USA.
RP Morscher, GN (reprint author), NASA, Glenn Res Ctr, Ohio Aerosp Inst, 21000 Brookpark Rd,MS 106-5, Cleveland, OH 44135 USA.
EM gmorscher@sbcglobal.net
FU Materials & Manufacturing Directorate; Air Force Research Laboratory
(AFRL/RXL); Wright-Patterson AFB [F33615-01-C-5234,
F33615-03-D-2354-D004]
FX The Materials & Manufacturing Directorate, Air Force Research Laboratory
(AFRL/RXL), Wright-Patterson AFB sponsored this work under contracts
F33615-01-C-5234 and F33615-03-D-2354-D004.
NR 19
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U1 4
U2 34
PU ELSEVIER SCI LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND
SN 0266-3538
J9 COMPOS SCI TECHNOL
JI Compos. Sci. Technol.
PD DEC
PY 2008
VL 68
IS 15-16
BP 3305
EP 3313
DI 10.1016/j.compscitech.2008.08.028
PG 9
WC Materials Science, Composites
SC Materials Science
GA 383JR
UT WOS:000261670400035
ER
PT J
AU Hinchey, M
Curto, PA
Hamilton, S
AF Hinchey, Mike
Curto, Paul A.
Hamilton, Scott
TI Computer Celebrates NASA's 50th Anniversary
SO COMPUTER
LA English
DT Editorial Material
C1 [Curto, Paul A.] NASA, Invent & Contribut Board, Washington, DC USA.
[Hinchey, Mike] NASA, Software Engn Lab, Washington, DC USA.
EM mike.hinchey@lero.ie; pcurto@comcast.net; shamilton@computer.org
NR 0
TC 0
Z9 0
U1 0
U2 0
PU IEEE COMPUTER SOC
PI LOS ALAMITOS
PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA
SN 0018-9162
J9 COMPUTER
JI Computer
PD DEC
PY 2008
VL 41
IS 12
BP 32
EP 33
PG 2
WC Computer Science, Hardware & Architecture; Computer Science, Software
Engineering
SC Computer Science
GA 388CT
UT WOS:000261998600015
ER
PT J
AU Bajracharya, M
Maimone, MW
Helmick, D
AF Bajracharya, Max
Maimone, Mark W.
Helmick, Daniel
TI Autonomy for Mars Rovers: Past, Present, and Future
SO COMPUTER
LA English
DT Article
AB The vehicles used to explore the Martian surface require a high degree of autonomy to navigate challenging and unknown terrain, investigate targets, and detect scientific events. Autonomy software allows such vehicles to make decisions and command actuators based on their observations of the environment or sensor feedback. Increased autonomy will be critical to the success of future missions, in which rovers will be expected to travel over long distances in a short time and handle dynamic processes such as taking a core sample from a rock while slipping on a slope.
C1 [Bajracharya, Max] CALTECH, Mobil & Manipulat Grp, Mobil & Robot Syst Sect, Jet Prop Lab, Pasadena, CA 91125 USA.
RP Bajracharya, M (reprint author), CALTECH, Mobil & Manipulat Grp, Mobil & Robot Syst Sect, Jet Prop Lab, Pasadena, CA 91125 USA.
EM maxb@robotics.jpl.nasa.gov; mwm@robotics.jpl.nasa.gov;
dhelmick@robotics.jpl.nasa.gov
FU Jet Propulsion Laboratory; California Institute of Technology; National
Aeronautics and Space Administration; NASA MER; Mars Technology Program;
Software Intelligent Systems and Modeling; New Millennium Program
FX The work described in this article was carried out at the Jet Propulsion
Laboratory, California Institute of Technology, under a contract to the
National Aeronautics and Space Administration, with funding provided by
the NASA MER project, Mars Technology Program, Software Intelligent
Systems and Modeling program, and New Millennium Program.
NR 13
TC 33
Z9 35
U1 0
U2 6
PU IEEE COMPUTER SOC
PI LOS ALAMITOS
PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA
SN 0018-9162
J9 COMPUTER
JI Computer
PD DEC
PY 2008
VL 41
IS 12
BP 44
EP +
PG 8
WC Computer Science, Hardware & Architecture; Computer Science, Software
Engineering
SC Computer Science
GA 388CT
UT WOS:000261998600017
ER
PT J
AU Kumar, S
Peters-Lidard, C
Tian, YD
Reichle, R
Geiger, J
Alonge, C
Eylander, J
Houser, P
AF Kumar, Sujay
Peters-Lidard, Christa
Tian, Yudong
Reichle, Rolf
Geiger, James
Alonge, Charles
Eylander, John
Houser, Paul
TI An Integrated Hydrologic Modeling and Data Assimilation Framework
SO COMPUTER
LA English
DT Article
ID LAND INFORMATION-SYSTEM; SURFACE PROCESSES; ABSORBED PAR; LEAF-AREA;
VEGETATION; IMPACT; SIMULATIONS; PREDICTION
AB Recent advances in remote sensing technologies have enabled the monitoring and measurement of Earth's land surface. Such provide data about Earth's vegetation, water, and energy fluxes. These must be integrated with state-of-the-art land-surface model forecasts using data assimilation tools to generate spatially and temporally continuous estimates of environmental conditions.
The need to develop modeling systems that identify and represent connections between land-surface hydrology and different components of the Earth system provides another key requirement for advancing hydrological prediction capabilities.
C1 [Kumar, Sujay; Peters-Lidard, Christa; Tian, Yudong; Reichle, Rolf; Geiger, James; Alonge, Charles] NASA, Goddard Space Flight Ctr, Washington, DC 20546 USA.
[Houser, Paul] George Mason Univ, Fairfax, VA 22030 USA.
RP Kumar, S (reprint author), NASA, Goddard Space Flight Ctr, Washington, DC 20546 USA.
EM sujay.kumar@nasa.gov; christa.peters@nasa.gov; yudong.tian@nasa.gov;
rolf.reichle@nasa.gov; james.v.geiger@nasa.gov; john.eylander@us.af.mil;
prhouser@gmail.com
RI Peters-Lidard, Christa/E-1429-2012; Reichle, Rolf/E-1419-2012; Houser,
Paul/J-9515-2013; Kumar, Sujay/B-8142-2015; Measurement,
Global/C-4698-2015
OI Peters-Lidard, Christa/0000-0003-1255-2876; Houser,
Paul/0000-0002-2991-0441;
FU NASA's Earth Science Technology Office; Computational Technologies
project; NASA ESTO Advanced Information Systems Technologies; US Army
Corps of Engineers and US Department of Agriculture; US Air Force
Weather Agency; Joint Center for Satellite Data Assimilation; NASA
Energy and Water Cycle Program; NASA Earth Observing System; NASA
Goddard Space Flight Center; GLDAS; NLDAS
FX We acknowledge the support from NASA's Earth Science Technology Office,
Computational Technologies project, which originally funded LIS
development. We also acknowledge the additional support of the NASA ESTO
Advanced Information Systems Technologies program, the US Army Corps of
Engineers and US Department of Agriculture, and more recent support from
our partners at the US Air Force Weather Agency, Joint Center for
Satellite Data Assimilation, the NASA Energy and Water Cycle Program,
the NASA Earth Observing System program, and an internal investment from
NASA Goddard Space Flight Center. In addition, the LIS team appreciates
the support and assistance of the GLDAS and NLDAS teams.
NR 42
TC 14
Z9 14
U1 0
U2 5
PU IEEE COMPUTER SOC
PI LOS ALAMITOS
PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA
SN 0018-9162
J9 COMPUTER
JI Computer
PD DEC
PY 2008
VL 41
IS 12
BP 52
EP +
PG 9
WC Computer Science, Hardware & Architecture; Computer Science, Software
Engineering
SC Computer Science
GA 388CT
UT WOS:000261998600018
ER
PT J
AU Post, RB
Welch, RB
Whitney, D
AF Post, Robert B.
Welch, Robert B.
Whitney, David
TI Egocentric and allocentric localization during induced motion
SO EXPERIMENTAL BRAIN RESEARCH
LA English
DT Article
DE Localization; Induced motion; Motion perception
ID VISUAL-MOTION; PERCEPTION; POSITION; MOVEMENTS; ILLUSION; TARGET; HAND;
DISSOCIATION; INFORMATION; LOCATION
AB This research examined motor measures of the apparent egocentric location and perceptual measures of the apparent allocentric location of a target that was being seen to undergo induced motion (IM). In Experiments 1 and 3, subjects fixated a stationary dot (IM target) while a rectangular surround stimulus (inducing stimulus) oscillated horizontally. The inducing stimulus motion caused the IM target to appear to move in the opposite direction. In Experiment 1, two dots (flashed targets) were flashed above and below the IM target when the surround had reached its leftmost or rightmost displacement from the subject's midline. Subjects pointed open-loop at either the apparent egocentric location of the IM target or at the bottom of the two flashed targets. On separate trials, subjects made judgments of the Vernier alignment of the IM target with the flashed targets at the endpoints of the surround's oscillation. The pointing responses were displaced in the direction of the previously seen IM for the IM target and to a lesser degree for the bottom flashed target. However, the allocentric Vernier judgments demonstrated no perceptual displacement of the IM target relative to the flashed targets. Thus, IM results in a dissociation of egocentric location measures from allocentric location measures. In Experiment 2, pointing and Vernier measures were obtained with stationary horizontally displaced surrounds and there was no dissociation of egocentric location measures from allocentric location measures. These results indicate that the Roelofs effect did not produce the pattern of results in Experiment 1. In Experiment 3, pointing and Vernier measures were obtained when the surround was at the midpoint of an oscillation. In this case, egocentric pointing responses were displaced in the direction of surround motion (opposite IM) for the IM target and to a greater degree for the bottom flashed target. However, there was no apparent displacement of the IM target relative to the flashed targets in the allocentric Vernier judgments. Therefore, in Experiment 3 egocentric location measures were again dissociated from allocentric location measures. The results of this experiment also demonstrate that IM does not generate an allocentric displacement illusion analogous to the "flash-lag" effect.
C1 [Post, Robert B.; Whitney, David] Univ Calif Davis, Dept Psychol, Davis, CA 95616 USA.
[Welch, Robert B.] NASA, Ames Res Ctr, Mountain View, CA 94035 USA.
[Whitney, David] Univ Calif Davis, Ctr Mind & Brain, Davis, CA 95616 USA.
RP Post, RB (reprint author), Univ Calif Davis, Dept Psychol, Davis, CA 95616 USA.
EM rbpost@ucdavis.edu
FU NEI NIH HHS [R01 EY018216, R01 EY018216-02]
NR 43
TC 2
Z9 2
U1 0
U2 3
PU SPRINGER
PI NEW YORK
PA 233 SPRING ST, NEW YORK, NY 10013 USA
SN 0014-4819
J9 EXP BRAIN RES
JI Exp. Brain Res.
PD DEC
PY 2008
VL 191
IS 4
BP 495
EP 504
DI 10.1007/s00221-008-1550-2
PG 10
WC Neurosciences
SC Neurosciences & Neurology
GA 366GV
UT WOS:000260469600010
PM 18751688
ER
PT J
AU Mahdi, LE
Statzell-Tallman, A
Fell, JW
Brown, MV
Donachie, SP
AF Mahdi, Leena E.
Statzell-Tallman, Adele
Fell, Jack W.
Brown, Mark V.
Donachie, Stuart P.
TI Sympodiomycopsis lanaiensis sp nov., a basidiomycetous yeast
(Ustilaginomycotina: Microstromatales) from marine driftwood in Hawai'i
SO FEMS YEAST RESEARCH
LA English
DT Article
DE Sympodiomycopsis; yeast; Hawai'i; wood
ID HYPERSALINE LAKE; GENUS; FUNGI; IDENTIFICATION; BIODIVERSITY
AB A previously unknown basidiomycetous yeast is described for which the name Sympodiomycopsis lanaiensis is proposed. The type strain, LM418(T), was isolated from driftwood collected on a beach on Lana'i (Hawai'i). On the basis of ribosomal DNA sequence analysis [large subunit (LSU), internal transcribed spacer (ITS) 1 & 2, and 18S], LM418(T) belongs to the order Microstromatales, which includes the genera Sympodiomycopsis, Rhodotorula, Microstroma, Volvocisporium and Quambalaria. The strain is described as a new species in the genus Sympodiomycopsis on the basis of morphological and physiological characteristics and the phylogenetic relationship to Sympodiomycopsis paphiopedili. Sexual reproduction was not observed in LM418(T). GenBank accession numbers for nucleotide sequences of regions of the LSU, ITS and 18S regions of the ribosomal operon in LM418(T) are DQ990016 DQ990017, DQ990018, respectively. LM418(T) has been deposited in the DSMZ as DSM 18755, in the ATCC as MYA-4092, in the Agricultural Research Service Culture Collection as NRRL Y-48466, and the Centraalbureau voor Schimmelcultures as CBS 10858.
C1 [Mahdi, Leena E.; Donachie, Stuart P.] Univ Hawaii, Dept Microbiol, Honolulu, HI 96822 USA.
[Statzell-Tallman, Adele; Fell, Jack W.] Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, Key Biscayne, FL USA.
[Brown, Mark V.] Univ Hawaii, NASA Astrobiol Inst, Inst Astron, Honolulu, HI 96822 USA.
RP Donachie, SP (reprint author), Univ Hawaii, Dept Microbiol, Snyder Hall 2538 McCarthy Mall, Honolulu, HI 96822 USA.
EM donachie@hawaii.edu
FU University of Hawai'i Pacific Research Center for Marine Biomedicine;
National Institute of Environmental Health Sciences [P50ES012740];
National Institutes of Health; National Science Foundation
[OCE04-32479]; NSF & NIEHS Ocean and Human Health Center Program [NSF
0432368, NIEHS P50 ES12736, NSF DEB 0206521]; American Philosophical
Society 'Lewis and Clark Exploration Award'; NASA Astrobiology Institute
[NNA04CC08A]
FX This research was funded by awards to S. P. D. under a Pilot Project
program from the University of Hawai'i Pacific Research Center for
Marine Biomedicine, part of the Centers for Oceans and Human Health
(COHH) program of the National Institute of Environmental Health
Sciences (P50ES012740), National Institutes of Health, and the National
Science Foundation (OCE04-32479), PIs Drs Edward Laws and Richard
Yanagihara. Funding at Rosenstiel School of Marine and Atmospheric
Science was provided in part by NSF & NIEHS Ocean and Human Health
Center Program (NSF 0432368 and NIEHS P50 ES12736) and NSF DEB 0206521.
Travel costs were supported in part by an American Philosophical Society
'Lewis and Clark Exploration Award' to L. E. M. M. V. B. acknowledges
support from the NASA Astrobiology Institute under Cooperative Agreement
NNA04CC08A at the Institute for Astronomy (University of Hawai'i at
Manoa).
NR 33
TC 6
Z9 6
U1 1
U2 5
PU WILEY-BLACKWELL
PI MALDEN
PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA
SN 1567-1356
J9 FEMS YEAST RES
JI FEMS Yeast Res.
PD DEC
PY 2008
VL 8
IS 8
BP 1357
EP 1363
DI 10.1111/j.1567-1364.2008.00448.x
PG 7
WC Biotechnology & Applied Microbiology; Microbiology; Mycology
SC Biotechnology & Applied Microbiology; Microbiology; Mycology
GA 367FG
UT WOS:000260537300016
PM 19054136
ER
PT J
AU Putzeys, OM
Fernandez-Pello, AC
Rein, G
Urban, DL
AF Putzeys, Olivier M.
Fernandez-Pello, A. Carlos
Rein, Guillermo
Urban, David L.
TI The piloted transition to flaming in smoldering fire retarded and
non-fire retarded polyurethane foam
SO FIRE AND MATERIALS
LA English
DT Article
DE smoldering; transition to flaming; piloted ignition; polyurethane foam;
fire retardants
ID TRIS(1,3-DICHLORO-2-PROPYL) PHOSPHATE; THERMAL-DECOMPOSITION; IGNITION;
COMBUSTION; FLAMMABILITY; PROPAGATION; RETARDATION; PYROLYSIS; BEHAVIOR;
MELAMINE
AB The piloted transition from smoldering to flaming, though a significant fire safety concern, has not been previously extensively studied. Experimental results are presented on the piloted transition from smoldering to flaming in non-fire retarded (NFR) polyurethane foam and the fire retarded polyurethane foam Pyrell (R). The samples are small blocks, vertically placed in the wall of an upward wind tunnel. The free surface is exposed to an oxidizer flow and a radiant heat flux. The smolder product gases pass upwards through a pilot. The experiments on NFR foam show that the smolder velocity and peak smolder temperature, which increase with the oxygen concentration and heat flux, are strongly correlated to the transition to flaming event, in that there are minimum values of these parameters for transition to occur. The existence of a minimum smolder velocity for ignition supports the concept of a gaseous mixture reaching a lean flammability limit as the criterion for the transition to flaming. To compensate for the solid- and gas-phase effects of the fire retardants on the piloted transition in Pyrell, it was necessary to increase the oxygen concentration and the power supplied to the smolder igniter and the pilot. The piloted transition is observed in oxygen concentrations above 17% in NFR foam and above 23% in Pyrell. The results show that although Pyrell is less flammable than NFR foam, it is still susceptible to smoldering and the piloted transition to flaming in oxygen-enriched environments, which is of interest for special applications such as future space missions. Copyright (c) 2008 John Wiley & Sons, Ltd.
C1 [Putzeys, Olivier M.; Fernandez-Pello, A. Carlos] Univ Calif Berkeley, Dept Mech Engn, Berkeley, CA 94720 USA.
[Rein, Guillermo] Univ Edinburgh, Edinburgh EH9 3JL, Midlothian, Scotland.
[Urban, David L.] NASA, Glenn Res Ctr, Cleveland, OH 44135 USA.
RP Fernandez-Pello, AC (reprint author), Univ Calif Berkeley, Dept Mech Engn, 6105A Etcheverry Hall, Berkeley, CA 94720 USA.
EM ferpello@me.berkeley.edu
OI Rein, Guillermo/0000-0001-7207-2685
FU NASA Glenn Research Center [NCC 05-AA49A]; NASA Graduate Student
Research Program
FX The authors would like to thank Winston Chiang, Jesse Limtiaco, and
Patrick Faner for their help conducting the experiments, and David Rich
and Chris Lautenberger for their advice and suggestions. The authors
also gratefully acknowledge the support of the STAF engineering team at
NASA Glenn Research Center, as well as NASA for funding this research
under grant #NCC 05-AA49A and the NASA Graduate Student Research
Program.
NR 34
TC 7
Z9 7
U1 1
U2 20
PU JOHN WILEY & SONS LTD
PI CHICHESTER
PA THE ATRIUM, SOUTHERN GATE, CHICHESTER PO19 8SQ, W SUSSEX, ENGLAND
SN 0308-0501
J9 FIRE MATER
JI Fire Mater.
PD DEC
PY 2008
VL 32
IS 8
BP 485
EP 499
DI 10.1002/fam.981
PG 15
WC Materials Science, Multidisciplinary
SC Materials Science
GA 385PQ
UT WOS:000261826500003
ER
PT J
AU Gregoire, TG
Lin, QF
Boudreau, J
Nelson, R
AF Gregoire, Timothy G.
Lin, Qi Feng
Boudreau, Johnathan
Nelson, Ross
TI Regression Estimation Following the Square-Root Transformation of the
Response
SO FOREST SCIENCE
LA English
DT Article
DE back-transfomation bias; nonlinearity
ID LINEAR MODELS; VARIANCE; BIOMASS; BIAS
AB In a variety of regression Situations, there is interest in predicting the Value of Y(2), yet it is useful to model it using a square root trans formation, such that Y rather than Y2 is regressed on one or more covariates. The back-transformation bias of the square root transformation of the response variable of interest is presented 42 in detail. All unbiased estimator is presented: (E) over cap [Y(2)/x(*)] = (mu) over cap (2)(y/x*) + (sigma) over cap - (V) over cap((mu) over cap (2)(y/x*)). Its performance is compared against that of two biased estimators: (E) over cap (b)[Y(2)/x(*)] = (mu) over cap (2)(y/x*) + (sigma) over cap and (E) over cap [Y(2)/x(*)] = (mu) over cap (2)(y/x*). The first two moments of these estimators are derived analytically and verified by means of a simulation study. Both biased estimators have lower mean square errors than the unbiased estimator. An example wherein aboveground biomass is the response variable is presented for illustration, FOR. Sci. 54(6):597-606.
C1 [Gregoire, Timothy G.] Yale Univ, Sch Forestry & Environm Studies, New Haven, CT 06511 USA.
[Boudreau, Johnathan] Univ Laval, Quebec City, PQ G1K 7P4, Canada.
[Nelson, Ross] NASA, Goddard Space Flight Ctr, Washington, DC USA.
RP Gregoire, TG (reprint author), Yale Univ, Sch Forestry & Environm Studies, 360 Prospect St, New Haven, CT 06511 USA.
EM timothy.gregoire@yale.edu; qifeng.lin@yale.edu;
johnathan.boudreau.1@ulaval.ca; Ross.F.Nelson@nasa.gov
RI Nelson, Ross/H-8266-2014
NR 21
TC 24
Z9 24
U1 2
U2 5
PU SOC AMER FORESTERS
PI BETHESDA
PA 5400 GROSVENOR LANE, BETHESDA, MD 20814 USA
SN 0015-749X
J9 FOREST SCI
JI For. Sci.
PD DEC
PY 2008
VL 54
IS 6
BP 597
EP 606
PG 10
WC Forestry
SC Forestry
GA 387AQ
UT WOS:000261924500004
ER
PT J
AU Carlson, AE
Oppo, DW
Came, RE
LeGrande, AN
Keigwin, LD
Curry, WB
AF Carlson, Anders E.
Oppo, Delia W.
Came, Rosemarie E.
LeGrande, Allegra N.
Keigwin, Lloyd D.
Curry, William B.
TI Subtropical Atlantic salinity variability and Atlantic meridional
circulation during the last deglaciation
SO GEOLOGY
LA English
DT Article
ID THERMOHALINE CIRCULATION; NORTH-ATLANTIC; TROPICAL ATLANTIC;
SURFACE-TEMPERATURE; CLIMATE CHANGES; OCEAN; RESUMPTION; PERIODS
AB During the last deglaciation (ca. 21-10 ka), freshening of the North Atlantic surface likely caused reductions in Atlantic meridional overturning circulation (AMOC); the mechanisms related to AMOC recovery remain poorly understood. Here we present three new deglacial surface temperature and delta O-18(seawater) (delta O-18(sw)) reconstructions from the western subtropical North and South Atlantic. Similarities to tropical Caribbean and western Atlantic delta O-18(sw) records suggest that a salty surface water mass accumulated in the western Atlantic from 27 degrees S to 33 degrees N during periods of reduced AMOC. However, delta O-18(sw) decreases led deep AMOC resumption by hundreds of years. We suggest that the northward export of salt previously trapped in the western Atlantic resulted in the early establishment of a shallow overturning circulation that eventually culminated in deep AMOC resumption, implying that AMOC may constitute a self-limiting system.
C1 [Carlson, Anders E.; Oppo, Delia W.; Keigwin, Lloyd D.; Curry, William B.] Woods Hole Oceanog Inst, Dept Geol & Geophys, Woods Hole, MA 02543 USA.
[Came, Rosemarie E.] CALTECH, Pasadena, CA 91125 USA.
[LeGrande, Allegra N.] Columbia Univ, NASA, Goddard Inst Space Studies, New York, NY 10025 USA.
[LeGrande, Allegra N.] Columbia Univ, Ctr Climate Syst Res, New York, NY 10025 USA.
RP Carlson, AE (reprint author), Univ Wisconsin, Dept Geol & Geophys, 1215 W Dayton St, Madison, WI 53706 USA.
EM acarlson@geology.wisc.edu
RI LeGrande, Allegra/D-8920-2012
OI LeGrande, Allegra/0000-0002-5295-0062
NR 32
TC 42
Z9 43
U1 1
U2 20
PU GEOLOGICAL SOC AMER, INC
PI BOULDER
PA PO BOX 9140, BOULDER, CO 80301-9140 USA
SN 0091-7613
EI 1943-2682
J9 GEOLOGY
JI Geology
PD DEC
PY 2008
VL 36
IS 12
BP 991
EP 994
DI 10.1130/G25080A.1
PG 4
WC Geology
SC Geology
GA 381WN
UT WOS:000261566700021
ER
PT J
AU Smith, JG
Connell, JW
Delozier, DM
Watson, KA
Bekyarova, E
Yu, A
Haddon, RC
AF Smith, J. G., Jr.
Connell, J. W.
Delozier, D. M.
Watson, K. A.
Bekyarova, E.
Yu, A.
Haddon, R. C.
TI Preparation and Properties of Nanocomposites from Pristine and Modified
SWCNTs of Comparable Average Aspect Ratios
SO HIGH PERFORMANCE POLYMERS
LA English
DT Article
DE polyimide; alkoxysilane terminated polyimides; electrical conductivity;
nanocomposites
ID WALLED CARBON NANOTUBES; ELECTROSTATIC CHARGE MITIGATION; FILMS;
PURIFICATION; TRANSPARENT; COATINGS; ACID
AB Low color, flexible, space-durable polyimide films with inherent and robust electrical conductivity to dissipate electrostatic charge (ESC) have been under investigation as part of a materials development activity for future NASA space missions. The use of single-walled carbon nanotubes (SWCNTs) is one means of achieving this goal. Even though the concentration of SWCNTs needed to achieve ESC dissipation is typically low, it is dependent upon purity, size, dispersion and functionalization. In this study, SWCNTs prepared by the electric arc discharge method were used to synthesize nanocomposites using the LaRC (TM) CP2 backbone as the matrix. Pristine and functionalized SWCNTs were mixed with an alkoxysilane terminated amide acid of LaRCTM CP2 and the soluble imide form of the polymer and the resultant nanocomposites evaluated for mechanical, thermal and electrical properties. Due to the preparative conditions for the pristine and functionalized SWCNTs, the average aspect ratio for both was comparable. This permitted the assessment of SWCNT functionalization with respect to various interactions ( e. g. van der Waals, hydrogen bonding, covalent bond formation, etc.) with the matrix and the macroscopic effects upon nanocomposite properties. The results of the study are described.
C1 [Smith, J. G., Jr.; Connell, J. W.] NASA, Langley Res Ctr, Hampton, VA 23681 USA.
[Delozier, D. M.; Watson, K. A.] Natl Inst Aerosp, Hampton, VA 23666 USA.
[Bekyarova, E.; Yu, A.; Haddon, R. C.] Univ Calif Riverside, Dept Chem, Riverside, CA 92521 USA.
RP Smith, JG (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA.
EM joseph.g.smith@nasa.gov
RI Haddon, Robert/A-2528-2008
OI Haddon, Robert/0000-0002-7903-5139
NR 23
TC 3
Z9 3
U1 1
U2 6
PU SAGE PUBLICATIONS LTD
PI LONDON
PA 1 OLIVERS YARD, 55 CITY ROAD, LONDON EC1Y 1SP, ENGLAND
SN 0954-0083
J9 HIGH PERFORM POLYM
JI High Perform. Polym.
PD DEC
PY 2008
VL 20
IS 6
BP 567
EP 587
DI 10.1177/0954008307085009
PG 21
WC Polymer Science
SC Polymer Science
GA 371OJ
UT WOS:000260840300002
ER
PT J
AU Wheeler, RM
AF Wheeler, Raymond M.
TI A Historical Background of Plant Lighting: An Introduction to the
Workshop
SO HORTSCIENCE
LA English
DT Editorial Material
ID GROWTH
C1 NASA, Biol Sci Off, Kennedy Space Ctr, FL 32899 USA.
RP Wheeler, RM (reprint author), NASA, Biol Sci Off, Mail Code KT-B-1, Kennedy Space Ctr, FL 32899 USA.
NR 20
TC 24
Z9 26
U1 1
U2 6
PU AMER SOC HORTICULTURAL SCIENCE
PI ALEXANDRIA
PA 113 S WEST ST, STE 200, ALEXANDRIA, VA 22314-2851 USA
SN 0018-5345
J9 HORTSCIENCE
JI Hortscience
PD DEC
PY 2008
VL 43
IS 7
BP 1942
EP 1943
PG 2
WC Horticulture
SC Agriculture
GA 374ZO
UT WOS:000261082400001
ER
PT J
AU Benner, LAM
Ostro, SJ
Magri, C
Nolan, MC
Howell, ES
Giorgini, JD
Jurgens, RF
Margot, JL
Taylor, PA
Busch, MW
Shepard, MK
AF Benner, Lance A. M.
Ostro, Steven J.
Magri, Christopher
Nolan, Michael C.
Howell, Ellen S.
Giorgini, Jon D.
Jurgens, Raymond F.
Margot, Jean-Luc
Taylor, Patrick A.
Busch, Michael W.
Shepard, Michael K.
TI Near-Earth asteroid surface roughness depends on compositional class
SO ICARUS
LA English
DT Review
DE Near-Earth objects; Asteroids; Asteroids, surfaces; Asteroids,
composition; Radar observations
ID 2100 RA-SHALOM; RADAR OBSERVATIONS; OPTICAL OBSERVATIONS; REGOLITH
PROPERTIES; ROSETTA MISSION; PHYSICAL MODEL; OBJECTS; BINARY;
METEORITES; ITOKAWA
AB Radar observations of 214 near-Earth asteroids (NEAs) reveal a very strong correlation of circular polarization ratio with visible-infrared taxonomic class, establishing distinct differences in the centimeter-to-several-decimeter structural complexity of objects in different spectral classes. The correlation may be due to the intrinsic mechanical properties of different mineralogical assemblages but also may reflect very different formation ages and collisional histories. The highest ratios are measured for groups associated with achondritic igneous rocky meteorites: the E class, whose parent body may be 3103 Eger, and the V class, derived from the mainbelt asteroid (and Dawn mission target) 4 Vesta. (C) 2008 Elsevier Inc. All rights reserved.
C1 [Benner, Lance A. M.; Ostro, Steven J.; Giorgini, Jon D.; Jurgens, Raymond F.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[Magri, Christopher] Univ Maine, Farmington, ME 04938 USA.
[Nolan, Michael C.; Howell, Ellen S.] Natl Astron & Ionosphere Ctr, Arecibo Observ, Arecibo, PR 00612 USA.
[Margot, Jean-Luc; Taylor, Patrick A.] Cornell Univ, Dept Astron, Ithaca, NY 14853 USA.
[Busch, Michael W.] CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA.
[Shepard, Michael K.] Bloomsburg Univ Penn, Dept Geog & Geosci, Bloomsburg, PA 17815 USA.
RP Benner, LAM (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM lance.benner@jpl.nasa.gov
RI Margot, Jean-Luc/A-6154-2012; Nolan, Michael/H-4980-2012
OI Margot, Jean-Luc/0000-0001-9798-1797; Nolan, Michael/0000-0001-8316-0680
FU National Science Foundation (NSF); Jet Propulsion Laboratory (JPL);
National Aeronautics and Spice Administration (NASA)
FX We thank the technical staffs at the Arecibo Observatory and the
Goldstone Solar System Radar for help with the observations, L.M. Carter
for providing the 2004 VG64 data, I.N. Belskaya, R.P. Binzel, SJ. Bus,
F. De Meo, M.D. Hicks, and V. Reddy for providing NEA taxonomic
classifications in advance Of publication, K.G. Ellsworth for help with
Fig. 3, and A. Rivkin and B. Campbell for comments that improved the
manuscript. The Arecibo Observatory is part of the National Astronomy
and Ionosphere Center, which is operated by Cornell University under a
cooperative agreement with the National Science Foundation (NSF). Some
of this work was performed at the Jet Propulsion Laboratory (JPL),
California Institute of Technology, under contract with the National
Aeronautics and Spice Administration (NASA). This material is based in
part upon work Supported by NASA under the Science Mission Directorate
Research and Analysis Programs.
NR 101
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PU ACADEMIC PRESS INC ELSEVIER SCIENCE
PI SAN DIEGO
PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA
SN 0019-1035
EI 1090-2643
J9 ICARUS
JI Icarus
PD DEC
PY 2008
VL 198
IS 2
BP 294
EP 304
DI 10.1016/j.icarus.2008.06.010
PG 11
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 382TW
UT WOS:000261629300002
ER
PT J
AU Romani, PN
Jennings, DE
Bjoraker, GL
Sada, PV
McCabe, GH
Boyle, RJ
AF Romani, Paul N.
Jennings, Donald E.
Bjoraker, Gordon L.
Sada, Pedro V.
McCabe, George H.
Boyle, Robert J.
TI Temporally varying ethylene emission on Jupiter
SO ICARUS
LA English
DT Article
DE Jupiter, atmospheres; Aurorae; Atmospheres, composition; Photochemistry
ID JOVIAN AURORAL STRATOSPHERE; 121.6 NM; METHANE; PHOTOCHEMISTRY; PROBE;
ATMOSPHERE; NEPTUNE; ETHANE; MODEL; HYDROCARBONS
AB Ethylene (C2H4) emission has been measured in the poles and equator of Jupiter. The 949 cm(-1) spectra were recorded with a high resolution spectrometer at the McMath-Pierce telescope at Kitt Peak in October-November 1998 and at the Infrared Telescope Facility at Mauna Kea in June 2000. C2H4 is an important product of methane chemistry in the outer planets. Knowledge of its abundance can help discriminate among the various proposed sets of CH4 photolysis branching ratios at Ly-alpha, and determine the relative importance of the reaction pathways that produce C2H2 and C2H6. In the equatorial region the C2H4 emission is weak, and we were only able to detect it at high air-mass, near the limb. We derive a peak equatorial molar abundance Of C2H4 of 4.5 x 10(-7) -1.7 x 10(-6) near 2.2 x 10(-3) mbar, with a total column of 5.7 x 10(14) -2.2 x 10(15) molecules cm(-2) above 10 mbar depending upon choice of thermal profile. We observed enhanced C2H4 emission from the poles in the regions where auroras are seen in X-ray, UV, and near infrared images. In 2000 we measured a short-term change in the distribution of polar C2H4 emission; the emission in the north IR auroral "hot spot" decreased by a factor of three over a two-day interval. This transient behavior and the sensitivity Of C2H4 emission to temperature changes near its contribution peak at 5-10 microbar suggests that the polar enhancement is primarily a thermal effect coupled with vertical transport. comparing our observations from Kitt Peak and Mauna Kea shows that the C2H4 emission of the northern non-hot spot" auroral regions did not change over the three-year period while that in the southern polar regions decreased. Published by Elsevier Inc.
C1 [Romani, Paul N.; Jennings, Donald E.; Bjoraker, Gordon L.; McCabe, George H.] NASA, Goddard Space Flight Ctr, Planetary Syst Branch, Greenbelt, MD 20771 USA.
[Sada, Pedro V.] Univ Monterrey, Dept Fis & Matemat, Garza Garcia 66238, NL, Mexico.
[McCabe, George H.] Catholic Univ Amer, Inst Astrophys & Computat Sci, Washington, DC 20064 USA.
[Boyle, Robert J.] Dickinson Coll, Dept Phys & Astron, Carlisle, PA 17013 USA.
RP Romani, PN (reprint author), NASA, Goddard Space Flight Ctr, Planetary Syst Branch, Code 693, Greenbelt, MD 20771 USA.
EM paul.romani@nasa.gov
RI Romani, Paul/D-2729-2012; Bjoraker, Gordon/D-5032-2012; Jennings,
Donald/D-7978-2012
FU NASA; National Academy of Sciences/National Research Council Senior
Associateship
FX The authors wish to thank Claude Plymate of NSO and the staff of the
IRTF for their help in conducting the observations. We thank Bruno
Bezard for discussing his own ethylene results with us, Mike Desch for
discussions on solar activity at the time of our observations, and an
anonymous referee for comments related to the radiative-transfer model.
This work was supported in part by NASA's Planetary Astronomy Program.
During the 2000 observations R.J.B. was supported in part by a National
Academy of Sciences/National Research Council Senior Associateship.
NR 38
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U2 8
PU ACADEMIC PRESS INC ELSEVIER SCIENCE
PI SAN DIEGO
PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA
SN 0019-1035
EI 1090-2643
J9 ICARUS
JI Icarus
PD DEC
PY 2008
VL 198
IS 2
BP 420
EP 434
DI 10.1016/j.icarus.2008.05.027
PG 15
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 382TW
UT WOS:000261629300011
ER
PT J
AU Smith-Konter, B
Pappalardo, RT
AF Smith-Konter, Bridget
Pappalardo, Robert T.
TI Tidally driven stress accumulation and shear failure of Enceladus's
tiger stripes
SO ICARUS
LA English
DT Article
DE Enceladus; Tectonics; Tides, solid body; Ices, mechanical properties
ID STRIKE-SLIP-FAULT; ICE SHELL; NONSYNCHRONOUS ROTATION; POLAR WANDER;
TENSILE FAULTS; HALF-SPACE; STICK-SLIP; EUROPA; EARTHQUAKE; DEFORMATION
AB Straddling the south polar region of Saturn's moon Enceladus, the four principal "tiger stripe" fractures are a likely source of tectonic activity and plume generation. Here we investigate tidally driven stress conditions at the tiger stripe fractures through a combined analysis of shear and normal diurnal tidal stresses and accounting for additional stress at depth due to the overburden pressure. We Compute Coulomb failure conditions to assess failure location, timing, and direction (right- vs left-lateral slip) throughout the Enceladus orbital cycle and explore a Suite of model parameters that inhibit or promote shear failure at the tiger stripes. We Find that low coefficients of friction (mu(f) = 0.1-0.2) and shallow overburden depths (z = 2-4 km) permit shear failure along the tiger stripe faults, and that right-and/or left-lateral slip responses are possible. We integrate these conditions into a 3D time-dependent fault dislocation model to evaluate tectonic displacements and stress variations at depth during a tiger stripe orbital cycle. Depending on the sequence of stress accumulation and subsequent fault slip, which varies as a function of fault location and orientation, frictional coefficient, and fault depth, we estimate resolved shear stress accumulation of similar to 70 kPa prior to fault failure, which produces modeled strike-slip displacements on the order of similar to 0.5 m in the horizontal direction and similar to 5 mm in the vertical direction per slip event. Our models also indicate that net displacements on the order of 0.1 m per orbital cycle, in both right- and left-lateral directions, are possible for particular fault geometries and frictional parameters. Tectonic activity inferred from these analyses correlates with observed plume activity and temperature anomalies at Enceladus's South polar region. Moreover, these analyses provide important details of stress accumulation and the faulting cycle for icy satellites subjected to diurnal tidal stress. (C) 2008 Elsevier Inc. All rights reserved.
C1 [Smith-Konter, Bridget] Univ Texas El Paso, Dept Geol Sci, El Paso, TX 79968 USA.
[Smith-Konter, Bridget; Pappalardo, Robert T.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Smith-Konter, B (reprint author), Univ Texas El Paso, Dept Geol Sci, El Paso, TX 79968 USA.
EM brkonter@utep.edu
RI Smith-Konter, Bridget/D-2823-2011
OI Smith-Konter, Bridget/0000-0001-6004-1005
FU NASA [NNG06GF44G]; Jet Propulsion Laboratory's Director's Fellowship
Program; JPL-Caltech Postdoctoral Scholars Program; National Aeronautics
and Space Administration
FX We thank Scott Marshall and Bruce Bills for their extremely helpful
comments for improving this manuscript and clarifying the model. We also
thank Zane Selvans for providing both access and thorough guidance in
the use and application of Sat-Stress. We acknowledge the GIS mapping
efforts of Damhnait Gleeson. We also thank Francis Nimmo, Simon
Kattenhorn, Bruce Bills, David Sandwell, and Terry Hurford for their
valuable discussions and suggestions related to the research presented
here. This research was supported by the NASA Outer Planets Research
Program (NNG06GF44G), the Jet Propulsion Laboratory's Director's
Fellowship Program, and the JPL-Caltech Postdoctoral Scholars Program.
The research described in this paper was carried out at the jet
Propulsion Laboratory, California Institute of Technology, under a
contract with the National Aeronautics and Space Administration.
NR 72
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U1 2
U2 22
PU ACADEMIC PRESS INC ELSEVIER SCIENCE
PI SAN DIEGO
PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA
SN 0019-1035
EI 1090-2643
J9 ICARUS
JI Icarus
PD DEC
PY 2008
VL 198
IS 2
BP 435
EP 451
DI 10.1016/j.icarus.2008.07.005
PG 17
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 382TW
UT WOS:000261629300012
ER
PT J
AU Guo, Y
Qu, ZH
Braiman, Y
Zhang, ZY
Barhen, J
AF Guo, Yi
Qu, Zhihua
Braiman, Yehuda
Zhang, Zhenyu
Barhen, Jacob
TI Nanotribology and Nanoscale Friction SMOOTH SLIDING THROUGH FEEDBACK
CONTROL
SO IEEE CONTROL SYSTEMS MAGAZINE
LA English
DT Article
ID STABILIZATION; FORCES
C1 [Guo, Yi] Stevens Inst Technol, Dept Elect & Comp Engn, Hoboken, NJ 07030 USA.
[Qu, Zhihua] Univ Cent Florida, Sch Elect Engn & Comp Sci, Orlando, FL 32816 USA.
[Zhang, Zhenyu] Oak Ridge Natl Lab, Div Mat Sci & Technol, Oak Ridge, TN USA.
[Zhang, Zhenyu] Univ Tennessee, Knoxville, TN 37996 USA.
[Barhen, Jacob] Oak Ridge Natl Lab, Ctr Engn Sci Adv Res, Oak Ridge, TN 37831 USA.
[Barhen, Jacob] CALTECH, JPL, Neural Computat & Nonlinear Sci Grp, Pasadena, CA 91125 USA.
RP Guo, Y (reprint author), Stevens Inst Technol, Dept Elect & Comp Engn, Hoboken, NJ 07030 USA.
EM yguo1@stevens.edu
FU U.S. Department of Energy [FG02-03ER46091]; Division of Materials
Sciences and Engineering; Office of Basic Energy Sciences
[AC05-00OR22725]; Oak Ridge National Laboratory; Office of Naval
Research
FX Yehuda Braiman, Zhenyu Zhang, and Jacob Barhen would like to acknowledge
the support by the U.S. Department of Energy, Grant DE-FG02-03ER46091
(Zhenyu Zhang), and the Division of Materials Sciences and Engineering,
Office of Basic Energy Sciences, under contract DE-AC05-00OR22725 with
Oak Ridge National Laboratory, managed and operated by UT-Battelle, LLC.
Yehuda Braiman would also like to acknowledge the support of the Office
of Naval Research.
NR 30
TC 9
Z9 9
U1 2
U2 7
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA
SN 1066-033X
J9 IEEE CONTR SYST MAG
JI IEEE Control Syst. Mag.
PD DEC
PY 2008
VL 28
IS 6
BP 92
EP 100
DI 10.1109/MCS.2008.929420
PG 9
WC Automation & Control Systems
SC Automation & Control Systems
GA 378GE
UT WOS:000261308400009
ER
PT J
AU Huang, DQ
LaRocca, TR
Chang, MCF
Samoska, L
Fung, A
Campbell, RL
Andrews, M
AF Huang, Daquan
LaRocca, Tim R.
Chang, Mau-Chung Frank
Samoska, Lorene
Fung, Andy
Campbell, Richard L.
Andrews, Michael
TI Terahertz CMOS Frequency Generator Using Linear Superposition Technique
SO IEEE JOURNAL OF SOLID-STATE CIRCUITS
LA English
DT Article; Proceedings Paper
CT IEEE International Solid-State Circuits Conference (ISSCC)
CY FEB 03-07, 2008
CL San Francisco, CA
SP IEEE
DE CMOS Terahertz generator; DAC-to-RF conversion efficiency;
fundamental-to-fourth harmonic signal conversion ratio; linear
superposition (LS) circuit technique; phase noise of terahertz CMOS
signal generation; terahertz signal generation
ID TECHNOLOGY
AB A low Terahertz (324 GHz) frequency generator is realized in 90 nm CMOS by linearly superimposing quadruple (N = 4) phase shifted fundamental signals at one fourth of the output frequency (81 GHz). The developed technique minimizes the fundamental, second and third order harmonics without extra filtering and results in a high fundamental-to-4 th harmonic signal conversion ratio of 0.17 or - 15.4 dB. The demonstrated prototype produces a calibrated -46 dBm output power when biased at 1 V and 12 mA with 4 GHz tuning range and extrapolated phase noise of -91 dBc/Hz at 10 MHz frequency offset. The linear superposition (LS) technique can be generalized for all even number cases (N = 2k, where k = 1, 2, 3, 4, ... , n) with different tradeoffs in output power and frequency. As CMOS continues to scale, we anticipate the LS N = 4 VCO to generate signals beyond 2 Terahertz by using 22 nm CMOS and produce output power up to -1.5 dBm with 1.7% power added efficiency with an LS VCO + Class-B Power Amplifier cascaded circuit architecture.
C1 [Huang, Daquan; LaRocca, Tim R.; Chang, Mau-Chung Frank] Univ Calif Los Angeles, Los Angeles, CA 90095 USA.
[Samoska, Lorene; Fung, Andy] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[Campbell, Richard L.] Portland State Univ, Portland, OR 97207 USA.
[Andrews, Michael] Cascade Microtech Inc, Beaverton, OR 97006 USA.
RP Huang, DQ (reprint author), Univ Calif Los Angeles, Los Angeles, CA 90095 USA.
EM huangdq@gmail.com
RI Chang, Mau-Chung Frank/E-6444-2011;
OI Chang, Mau-Chung Frank/0000-0002-2934-9359
NR 18
TC 62
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U1 0
U2 6
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA
SN 0018-9200
J9 IEEE J SOLID-ST CIRC
JI IEEE J. Solid-State Circuit
PD DEC
PY 2008
VL 43
IS 12
BP 2730
EP 2738
DI 10.1109/JSSC.2008.2004868
PG 9
WC Engineering, Electrical & Electronic
SC Engineering
GA 385GD
UT WOS:000261801800014
ER
PT J
AU Rajagopalan, H
Rahmat-Samii, Y
Imbriale, WA
AF Rajagopalan, Harish
Rahmat-Samii, Yahya
Imbriale, William A.
TI RF MEMS Actuated Reconfigurable Reflectarray Patch-Slot Element
SO IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
LA English
DT Article
DE Patch; radio frequency micro-electromechanical system (RF MEMS);
reflectarray; slot
ID BAND MICROSTRIP REFLECTARRAY; ANTENNA; DESIGN
AB This paper describes the design of a reconfigurable reflectarray element using commercially available radio frequency micro-electromechanical system (RF MEMS) switches. The element consists of a microstrip patch on the top surface and a slot with an actuated variable length in the ground plane. RF MEMS switches are mounted on the slot to electronically vary the slot length by actuating the switches and thus obtaining the desired phase response. Waveguide measurements and High Frequency Structure Simulator (HFSS) simulations are used to characterize the reflectarray element. The four MEMS switches element gives 10 independent states with a phase swing of 150 degrees and a loss variation from 0.4 dB to 1.5 dB at 2 GHz (more switches can provide larger phase shift). The loss is mainly attributed to the dielectric loss and the conductor loss, which occur due to the relatively strong electric fields in the substrate region below the patch and the large currents on the top surface of the patch, respectively, close to the patch resonance. Detailed analysis is performed to characterize the effect of the switches by taking into consideration the switch model and wire bonding effects.
C1 [Rajagopalan, Harish; Rahmat-Samii, Yahya] Univ Calif Los Angeles, Dept Elect Engn, Los Angeles, CA 90095 USA.
[Imbriale, William A.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Rajagopalan, H (reprint author), Univ Calif Los Angeles, Dept Elect Engn, Los Angeles, CA 90095 USA.
EM harish@ee.ucla.edu; rahmat@ee.ucla.edu; imbriale@jpl.nasa.gov
NR 19
TC 57
Z9 58
U1 3
U2 16
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA
SN 0018-926X
J9 IEEE T ANTENN PROPAG
JI IEEE Trans. Antennas Propag.
PD DEC
PY 2008
VL 56
IS 12
BP 3689
EP 3699
DI 10.1109/TAP.2008.2007388
PG 11
WC Engineering, Electrical & Electronic; Telecommunications
SC Engineering; Telecommunications
GA 402RY
UT WOS:000263032000010
ER
PT J
AU Cooper, M
AF Cooper, Mark
TI Observations on Component Infant Mortality and Burn-In Effectiveness
SO IEEE TRANSACTIONS ON COMPONENTS AND PACKAGING TECHNOLOGIES
LA English
DT Article
DE Burn-in effectiveness; component failure distributions; early life
distribution; early life failures; infant mortality
C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Cooper, M (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
NR 13
TC 2
Z9 2
U1 0
U2 2
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA
SN 1521-3331
J9 IEEE T COMPON PACK T
JI IEEE Trans. Compon. Packaging Technol.
PD DEC
PY 2008
VL 31
IS 4
BP 914
EP 916
DI 10.1109/TCAPT.2008.2007187
PG 3
WC Engineering, Manufacturing; Engineering, Electrical & Electronic;
Materials Science, Multidisciplinary
SC Engineering; Materials Science
GA 381OH
UT WOS:000261545300020
ER
PT J
AU Blacksberg, J
Nikzad, S
Hoenk, ME
Holland, SE
Kolbe, WF
AF Blacksberg, Jordana
Nikzad, Shouleh
Hoenk, Michael E.
Holland, Stephen E.
Kolbe, William F.
TI Near-100% Quantum Efficiency of Delta Doped Large-Format UV-NIR Silicon
Imagers
SO IEEE TRANSACTIONS ON ELECTRON DEVICES
LA English
DT Article
DE Back illuminated; charge-coupled device (CCD); delta doping; fully
depleted; high-purity silicon
ID GROWTH; FILMS
AB We have demonstrated a back surface process for back-illuminated high-purity p-channel charge-coupled devices (CCDs), enabling broadband coverage from the ultraviolet to near infrared (NIR). The process consists of the formation of a delta layer followed by a double layer antireflection (AR) coating. The process is per-formed below 450 degrees C and is applied to fully fabricated CCDs with aluminum metallization. The delta doping process was demonstrated on 1 k x 1 k and 2 k x 4 k CCDs, which were found to exhibit low dark current and near reflection-limited quantum efficiency. Two broadband AR coatings were developed to cover the UV-visible and visible-NIR bands. These coatings consist of a double layer of Si(x)N(y) and SiO(x) deposited by plasma enhanced chemical vapor deposition onto the back surface of a delta doped CCD. The thicknesses of the coating layers are adjusted for the desired bandpass.
C1 [Blacksberg, Jordana; Nikzad, Shouleh; Hoenk, Michael E.] NASA, Jet Prop Lab, CALTECH, Pasadena, CA 91109 USA.
[Holland, Stephen E.; Kolbe, William F.] Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA.
RP Blacksberg, J (reprint author), NASA, Jet Prop Lab, CALTECH, Pasadena, CA 91109 USA.
EM jordana.blacksberg@jpl.nasa.gov; shouleh.nikzad@jpl.nasa.gov;
seholland@lbl.gov
RI Holland, Stephen/H-7890-2013
FU JPL's Research and Technology Development (R and TD); Director's
Research and Development Fund (DRDF); Director, Office of Science;
Office of Basic Energy Sciences; U.S. Department of Energy
[DE-AC02-05CH11231]
FX This work was supported in part by the JPL's Research and Technology
Development (R and TD) and the Director's Research and Development Fund
(DRDF) programs, in which research at the Jet Propulsion Laboratory,
California Institute of Technology, was carried out under a contract
with the National Aeronautics and Space Administration, and in part by
the Director, Office of Science, Office of Basic Energy Sciences, U.S.
Department of Energy under Contract DE-AC02-05CH11231. The review of
this paper was arranged by Editor
NR 12
TC 4
Z9 4
U1 0
U2 5
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA
SN 0018-9383
J9 IEEE T ELECTRON DEV
JI IEEE Trans. Electron Devices
PD DEC
PY 2008
VL 55
IS 12
BP 3402
EP 3406
DI 10.1109/TED.2008.2006779
PG 5
WC Engineering, Electrical & Electronic; Physics, Applied
SC Engineering; Physics
GA 380LJ
UT WOS:000261466900010
ER
PT J
AU Le Gall, A
Ciarletti, V
Berthelier, JJ
Reineix, A
Guiffaut, C
Ney, R
Dolon, F
Bonaime, S
AF Le Gall, Alice
Ciarletti, Valerie
Berthelier, Jean-Jacques
Reineix, Alain
Guiffaut, Christophe
Ney, Richard
Dolon, Francois
Bonaime, Sebastien
TI An Imaging HF GPR Using Stationary Antennas: Experimental Validation
Over the Antarctic Ice Sheet
SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING
LA English
DT Article
DE Deep soundings; finite-difference time domain (FDTD); ground-penetrating
radar (GPR); ice; Mars; subsurface; wave propagation
ID GROUND-PENETRATING RADAR; WEST ANTARCTICA; HIGH-RESOLUTION;
RADIATION-PATTERNS; FII TECHNIQUE; NETLANDER; MODEL; SUBSURFACE;
BENEATH; MARS
AB Terrestrial And Planetary Imaging Radar (TAPIR) is an innovative high-frequency ground-penetrating radar (GPR) developed in the frame of the Martian NetLander mission to probe the subsurface down to kilometric depths. Unlike most GPRs, TAPIR is able to image underground reflectors with stationary antennas. In this paper, after a brief presentation of the instrument, we describe the method developed to interpret data collected during the RAdar of NEtlander in Terre Adelie (RANETA) field survey in Antarctica. This method consists of retrieving the direction of arrival of each detected echo through the measurement of five components of the electromagnetic field (the three magnetic components and the horizontal components of the electric field). Thus, both the range and the direction of each individual reflection or diffraction due to the ice-bedrock interface are resolved. We validated this method on finite-difference time-domain numerically simulated data for different subsurface configurations before applying it to RANETA observations. In particular, the irregular topography of the bedrock in two sounding sites was revealed. We discuss the accuracy of our results.
C1 [Le Gall, Alice] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[Ciarletti, Valerie] Univ Versailles St Quentin En Yvelines, F-78035 Versailles, France.
[Berthelier, Jean-Jacques; Ney, Richard; Dolon, Francois] Inst Pierre Simon Laplace, Ctr Etud Environm Terrestre & Planetaires, F-94107 St Maur Des Fosses, France.
[Reineix, Alain; Guiffaut, Christophe] Univ Limoges, XLIM Lab, F-87032 Limoges, France.
[Bonaime, Sebastien] Inst Phys Globe, F-75005 Paris, France.
RP Le Gall, A (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM Alice.Le.Gall@jpl.nasa.gov
FU CNES [793/CNES/99/7947, 737/CNES/00/826]
FX The authors would like to thank the Institut polaire francais Paul-Emile
Victor (IPEV) for the organization of the RANETA campaign, CNES for
funding the development of the radar under Grant 793/CNES/99/7947 and
Grant 737/CNES/00/826, and S.A. Arcone for his constructive review.
NR 34
TC 12
Z9 12
U1 1
U2 6
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA
SN 0196-2892
J9 IEEE T GEOSCI REMOTE
JI IEEE Trans. Geosci. Remote Sensing
PD DEC
PY 2008
VL 46
IS 12
BP 3975
EP 3986
DI 10.1109/TGRS.2008.2000718
PG 12
WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote
Sensing; Imaging Science & Photographic Technology
SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science
& Photographic Technology
GA 385GC
UT WOS:000261801700003
ER
PT J
AU McGuire, PC
Wolff, MJ
Smith, MD
Arvidson, RE
Murchie, SL
Clancy, RT
Roush, TL
Cull, SC
Lichtenberg, KA
Wiseman, SM
Green, RO
Martin, TZ
Milliken, RE
Cavender, PJ
Humm, DC
Seelos, FP
Seelos, KD
Taylor, HW
Ehlmann, BL
Mustard, JF
Pelkey, SM
Titus, TN
Hash, CD
Malaret, ER
AF McGuire, Patrick C.
Wolff, Michael J.
Smith, Michael D.
Arvidson, Raymond E.
Murchie, Scott L.
Clancy, R. Todd
Roush, Ted L.
Cull, Selby C.
Lichtenberg, Kim A.
Wiseman, Sandra M.
Green, Robert O.
Martin, Terry Z.
Milliken, Ralph E.
Cavender, Peter J.
Humm, David C.
Seelos, Frank P.
Seelos, Kim D.
Taylor, Howard W.
Ehlmann, Bethany L.
Mustard, John F.
Pelkey, Shannon M.
Titus, Timothy N.
Hash, Christopher D.
Malaret, Erick R.
CA CRISM Team
TI MRO/CRISM Retrieval of Surface Lambert Albedos for Multispectral Mapping
of Mars With DISORT-Based Radiative Transfer Modeling: Phase 1-Using
Historical Climatology for Temperatures, Aerosol Optical Depths, and
Atmospheric Pressures
SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING
LA English
DT Article
DE Atmospheric propagation; infrared spectroscopy; remote sensing; software
verification and validation
ID BIDIRECTIONAL REFLECTANCE; OMEGA/MARS EXPRESS; MERIDIANI-PLANUM;
ALGORITHM; WATER; VALIDATION; MINERALS; REGION; LAND; SIZE
AB We discuss the DISORT-based radiative transfer pipeline ("CRISM_LambertAlb") for atmospheric and thermal correction of MRO/CRISM data acquired in multispectral mapping mode (similar to 200 m/pixel, 72 spectral channels). Currently, in this phase-one version of the system, we use aerosol optical depths, surface temperatures, and lower atmospheric temperatures, all from climatology derived from Mars Global Surveyor Thermal Emission Spectrometer (MGS-TES) data and from surface altimetry derived from MGS Mars Orbiter Laser Altimeter (MOLA). The DISORT-based model takes the dust and ice aerosol optical depths (scaled to the CRISM wavelength range), the surface pressures (computed from MOLA altimetry, MGS-TES lower atmospheric thermometry, and Viking-based pressure climatology), the surface temperatures, the reconstructed instrumental photometric angles, and the measured I/F spectrum as inputs, and then a Lambertian albedo spectrum is computed as the output. The Lambertian albedo spectrum is valuable geologically because it allows the mineralogical composition to be estimated. Here, I/F is defined as the ratio of the radiance measured by CRISM to the solar irradiance at Mars divided by pi; if there was no martian atmosphere, I/F divided by the cosine of the incidence angle would be equal to the Lambert albedo for a Lambertian surface. After discussing the capabilities and limitations of the pipeline software system, we demonstrate its application on several multispectral data cubes-particularly, the outer reaches of the northern ice cap of Mars, the Tyrrhena Terra area that is northeast of the Hellas basin, and an area near the landing site for the Phoenix mission in the northern plains. For the icy spectra near the northern polar cap, aerosols need to be included in order to properly correct for the CO2 absorption in the H2O ice bands at wavelengths near 2.0 mu m. In future phases of software development, we intend to use CRISM data directly in order to retrieve the spatiotemporal maps of aerosol optical depths, surface pressure, and surface temperature. This will allow a second level of refinement in the atmospheric and thermal correction of CRISM multispectral data.
C1 [McGuire, Patrick C.; Arvidson, Raymond E.; Cull, Selby C.; Lichtenberg, Kim A.; Wiseman, Sandra M.] Washington Univ, McDonald Ctr Space Sci, St Louis, MO 63130 USA.
[Wolff, Michael J.; Clancy, R. Todd] Space Sci Inst, Boulder, CO 80301 USA.
[Smith, Michael D.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
[Murchie, Scott L.; Cavender, Peter J.; Humm, David C.; Seelos, Frank P.; Seelos, Kim D.; Taylor, Howard W.] Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA.
[Roush, Ted L.] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
[Green, Robert O.; Martin, Terry Z.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[Ehlmann, Bethany L.; Mustard, John F.; Pelkey, Shannon M.] Brown Univ, Dept Geol Sci, Providence, RI 02912 USA.
[Titus, Timothy N.] US Geol Survey, Flagstaff, AZ 86001 USA.
[Hash, Christopher D.; Malaret, Erick R.] Appl Coherent Technol Corp, Herndon, VA 20170 USA.
RP McGuire, PC (reprint author), Washington Univ, McDonald Ctr Space Sci, St Louis, MO 63130 USA.
RI Smith, Michael/C-8875-2012; McGuire, Patrick/D-2962-2013; Murchie,
Scott/E-8030-2015; Seelos, Kimberly/F-4647-2015; Humm,
David/B-8825-2016; Seelos, Frank/C-7875-2016
OI McGuire, Patrick/0000-0001-6592-4966; Murchie,
Scott/0000-0002-1616-8751; Seelos, Kimberly/0000-0001-7236-0580; Humm,
David/0000-0003-1520-261X; Seelos, Frank/0000-0001-9721-941X
FU National Aeronautics and Space Administration (NASA); Jet Propulsion
Laboratory [1277793]; McDonnell Center for the Space Sciences; NASA
Graduate Student Research; MRO Participating Scientist [1300367];
MGS-TES; ODY/THEMIS; MRO project
FX Manuscript received October 4. 2007: revised March 25. 2008. Current
version published November 26. 2008, This work was supported by the
National Aeronautics and Space Administration (NASA) through the Applied
Physics Laboratory under subcontract from the Jet Propulsion Laboratory
through JPL Contract 1277793. The work of P. C. McGuire was supported by
it Robert M. Walker Senior Research Fellowship from the McDonnell Center
for the Space Sciences. The work of S. M. Wiseman was Supported by a
NASA Graduate Student Research Program fellowship. The work of T. N.
Titus was supported in part by MRO Participating Scientist Award 1300367
and in part by the MGS-TES and ODY/THEMIS projects. The work of T. Z.
Martin, R. O. Green. and R. E. Milliken was supported by the MRO
project.
NR 62
TC 24
Z9 25
U1 0
U2 13
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA
SN 0196-2892
EI 1558-0644
J9 IEEE T GEOSCI REMOTE
JI IEEE Trans. Geosci. Remote Sensing
PD DEC
PY 2008
VL 46
IS 12
BP 4020
EP 4040
DI 10.1109/TGRS.2008.2000631
PG 21
WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote
Sensing; Imaging Science & Photographic Technology
SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science
& Photographic Technology
GA 385GC
UT WOS:000261801700007
ER
PT J
AU Morrison, CR
Siebert, MW
Ho, EJ
AF Morrison, Carlos R.
Siebert, Mark W.
Ho, Eric J.
TI Electromagnetic Forces in a Hybrid Magnetic-Bearing Switched-Reluctance
Motor
SO IEEE TRANSACTIONS ON MAGNETICS
LA English
DT Article
DE Bearingless motor; electromagnetic device; hybrid motor; magnetic field
calculation; switched-reluctance motor
ID TORQUE RIPPLE
AB We have performed analysis and experimental measurement of the electromagnetic force loads on the hybrid rotor in a novel hybrid magnetic-bearing switched-reluctance motor (MBSRM). An MBSRM has the combined characteristics of a switched-reluctance motor and a magnetic bearing. The MBSRM discussed in this paper has an eight-pole stator and a six-pole hybrid rotor, which is composed of circular and scalloped lamination segments. The hybrid rotor is levitated with only one set of four stator poles, while a second set of four stator poles imparts torque to the scalloped portion of the rotor, which is driven in a traditional switched reluctance manner by a processor. We performed static torque and radial force analysis of rotor poles oriented to achieve maximum and minimum radial force loads on the rotor. The objective was to assess whether simple one-dimensional magnetic circuit analysis is sufficient for preliminary evaluation of this machine, which may exhibit strong three-dimensional electromagnetic field behavior. We employed two magnetic circuit geometries, approximating the complex topology of the magnetic fields in and around the hybrid rotor, in formulating the electromagnetic radial force equations. The experimental and the theoretical radial force load predictions agreed reasonably well with typical magnetic bearing derating factors applied to the predictions.
C1 [Morrison, Carlos R.; Ho, Eric J.] NASA, Glenn Res Ctr, Cleveland, OH 44135 USA.
[Siebert, Mark W.] Univ Toledo, Cleveland, OH 44135 USA.
[Ho, Eric J.] Univ Texas Arlington, Arlington, TX 76001 USA.
RP Morrison, CR (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA.
EM Carlos.R.Morrison@nasa.gov
RI cao, xin/C-1071-2009
NR 12
TC 23
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U1 0
U2 16
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA
SN 0018-9464
J9 IEEE T MAGN
JI IEEE Trans. Magn.
PD DEC
PY 2008
VL 44
IS 12
BP 4626
EP 4638
DI 10.1109/TMAG.2008.2002891
PG 13
WC Engineering, Electrical & Electronic; Physics, Applied
SC Engineering; Physics
GA 395XM
UT WOS:000262556800009
ER
PT J
AU Cooper, KB
Dengler, RJ
Llombart, N
Bryllert, T
Chattopadhyay, G
Schlecht, E
Gill, J
Lee, C
Skalare, A
Mehdi, I
Siegel, PH
AF Cooper, Ken B.
Dengler, Robert J.
Llombart, Nuria
Bryllert, Tomas
Chattopadhyay, Goutam
Schlecht, Erich
Gill, John
Lee, Choonsup
Skalare, Anders
Mehdi, Imran
Siegel, Peter H.
TI Penetrating 3-D Imaging at 4-and 25-m Range Using a Submillimeter-Wave
Radar
SO IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES
LA English
DT Article
DE Millimeter waves; submillimeter-wavelength imaging; terahertz radar;
terharertz (THz)
ID GHZ
AB We show experimentally that a high-resolution imaging radar operating at 576-605 GHz is capable of detecting weapons concealed by clothing at standoff ranges of 4-25 m. We also demonstrate the critical advantage of 3-D image reconstruction for visualizing hidden objects using active-illumination coherent terahertz imaging. The present system can image a torso with <1 cm resolution at 4 in standoff in about five minutes. Greater standoff distances and much higher frame rates should be achievable by capitalizing on the bandwidth, output power, and compactness of solid state Schottky-diode based terahertz mixers and multiplied sources.
C1 [Cooper, Ken B.; Dengler, Robert J.; Llombart, Nuria; Bryllert, Tomas; Chattopadhyay, Goutam; Schlecht, Erich; Gill, John; Lee, Choonsup; Skalare, Anders; Mehdi, Imran; Siegel, Peter H.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[Siegel, Peter H.] CALTECH, Dept Biol, Pasadena, CA 91125 USA.
RP Cooper, KB (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM phs@cal-tech.edu
FU National Aeronautics and Space Administration (NASA); Division of
Biology, California Institute of Technology; Naval Explosive Ordnance
Disposal Technology Division; Department of Defense (DoD) Physical
Security Equipment Action Group (PSEAG)
FX This work was supported by the National Aeronautics and Space
Administration (NASA) under a contract, by the Division of Biology,
California Institute of Technology, by the Naval Explosive Ordnance
Disposal Technology Division with funding provided by the Department of
Defense (DoD) Physical Security Equipment Action Group (PSEAG).
NR 9
TC 130
Z9 133
U1 4
U2 22
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA
SN 0018-9480
J9 IEEE T MICROW THEORY
JI IEEE Trans. Microw. Theory Tech.
PD DEC
PY 2008
VL 56
IS 12
BP 2771
EP 2778
DI 10.1109/TMTT.2008.2007081
PG 8
WC Engineering, Electrical & Electronic
SC Engineering
GA 386PN
UT WOS:000261895200012
ER
PT J
AU Pan, B
Li, Y
Ponchak, GE
Tentzeris, MM
Papapolymerou, J
AF Pan, Bo
Li, Yuan
Ponchak, George E.
Tentzeris, Manos M.
Papapolymerou, John
TI A Low-Loss Substrate-Independent Approach for 60-GHz Transceiver
Front-End Integration Using Micromachining Technologies
SO IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES
LA English
DT Article
DE Cavity resonator filter; millimeter wave; on-wafer pattern measurement;
silicon bulk micromachining; 60-GHz; SU-8; surface micromachining
ID ANTENNA; FILTERS; MEMS
AB This paper presents a low-loss, substrate-independent approach to integrate transceiver front-ends for 60-GHz wireless applications. Dielectric loss is eliminated by using polymer and bulk silicon micromachining technologies to create a cavity-based duplexer and a horn antenna in the air, above the substrate. A coplanar waveguide input is used for easy integration of the low-noise amplifier and power amplifier of the receiver and transmitter, respectively, with the micromachined passive module. A prototype is designed, fabricated, and characterized, with the transmit band (TX) set between 58.7-59.5 GHz and the receive band (RX) as 60.6-61.4 GHz. The proposed method offers an easy integration of both planar components and 3-D integrated modules on top of the substrate.
C1 [Pan, Bo; Li, Yuan; Tentzeris, Manos M.; Papapolymerou, John] Georgia Inst Technol, Sch Elect & Comp Engn, Atlanta, GA 30332 USA.
[Ponchak, George E.] NASA, Glenn Res Ctr, Cleveland, OH 44135 USA.
RP Pan, B (reprint author), Realtek Semicond, Irvine, CA 92602 USA.
EM bo.pan@realtek.com; yuanli@ece.gatech.edu; george.ponchak@ieee.org;
etentze@ece.gatech.edu; papapol@ece.gatech.edu
FU Georgia Research Alliance; U.S. Army Research Office
FX This work was supported in part by the Georgia Research Alliance and the
U.S. Army Research Office.
NR 20
TC 10
Z9 10
U1 0
U2 8
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA
SN 0018-9480
J9 IEEE T MICROW THEORY
JI IEEE Trans. Microw. Theory Tech.
PD DEC
PY 2008
VL 56
IS 12
BP 2779
EP 2788
DI 10.1109/TMTT.2008.2007358
PG 10
WC Engineering, Electrical & Electronic
SC Engineering
GA 386PN
UT WOS:000261895200013
ER
PT J
AU Schwank, J
Buchner, S
Marshall, P
Duzellier, S
Brown, D
Poivey, C
Pease, R
AF Schwank, Jim
Buchner, Steve
Marshall, Paul
Duzellier, Sophie
Brown, Dennis
Poivey, Christian
Pease, Ron
TI 2008 Special NSREC Issue of the IEEE TRANSACTIONS ON NUCLEAR SCIENCE
Comments by the Editors
SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE
LA English
DT Editorial Material
C1 [Schwank, Jim] Sandia Natl Labs, Livermore, CA 94550 USA.
[Buchner, Steve] NASA, GSFC Perot Syst, Washington, DC USA.
[Poivey, Christian] ESA, ESTEC, F-75738 Paris 15, France.
RP Schwank, J (reprint author), Sandia Natl Labs, Livermore, CA 94550 USA.
NR 0
TC 0
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U1 1
U2 6
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA
SN 0018-9499
J9 IEEE T NUCL SCI
JI IEEE Trans. Nucl. Sci.
PD DEC
PY 2008
VL 55
IS 6
BP 2810
EP 2810
DI 10.1109/TNS.2008.2009685
PG 1
WC Engineering, Electrical & Electronic; Nuclear Science & Technology
SC Engineering; Nuclear Science & Technology
GA 398DS
UT WOS:000262713400002
ER
PT J
AU Tipton, AD
Pellish, JA
Hutson, JM
Baumann, R
Deng, X
Marshall, A
Xapsos, MA
Kim, HS
Friendlich, MR
Campola, MJ
Seidleck, CM
Label, KA
Mendenhall, MH
Reed, RA
Schrimpf, RD
Weller, RA
Black, JD
AF Tipton, Alan D.
Pellish, Jonathan A.
Hutson, John M.
Baumann, Robert
Deng, Xiaowei
Marshall, Andrew
Xapsos, Michael A.
Kim, Hak S.
Friendlich, Mark R.
Campola, Michael J.
Seidleck, Christina M.
Label, Ken A.
Mendenhall, Marcus H.
Reed, Robert A.
Schrimpf, Ronald D.
Weller, Robert A.
Black, Jeff D.
TI Device-Orientation Effects on Multiple-Bit Upset in 65 nm SRAMs
SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE
LA English
DT Article
DE Multiple-bit upset; MBU; MCU; SEU; heavy ion; SRAM; MRED; GEANT4; soft
error
ID INDUCED SOFT ERRORS; CMOS TECHNOLOGY; SINGLE; NEUTRONS; MODEL
AB The effects of device orientation on heavy ion-induced multiple-bit upset (MBU) in 65 nm SRAMs are examined. The MBU response is shown to depend on the orientation of the device during irradiation. The response depends on the direction of the incident ion to the n- and p-wells of the SRAM. The MBU response is simulated using Monte Carlo methods for a space environment. The probability is calculated for event size. Single-bit upsets in the space environment account for 90% of all events with exponentially decreasing probabilities of larger MBU events.
C1 [Tipton, Alan D.; Pellish, Jonathan A.; Hutson, John M.] Vanderbilt Univ, Dept Elect Engn & Comp Sci, Nashville, TN 37235 USA.
[Baumann, Robert; Deng, Xiaowei; Marshall, Andrew] Texas Instruments Inc, Dallas, TX 75243 USA.
[Xapsos, Michael A.; Label, Ken A.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
[Kim, Hak S.; Friendlich, Mark R.; Campola, Michael J.; Seidleck, Christina M.] MEI Technol, Greenbelt, MD 20771 USA.
[Mendenhall, Marcus H.] Vanderbilt Univ, Dept Elect Engn & Comp Sci, WM Keck Free Elect Laser Ctr, Nashville, TN 37235 USA.
[Mendenhall, Marcus H.; Reed, Robert A.; Schrimpf, Ronald D.; Weller, Robert A.; Black, Jeff D.] Vanderbilt Univ, Inst Space & Def Elect, Nashville, TN 37235 USA.
RP Tipton, AD (reprint author), Vanderbilt Univ, Dept Elect Engn & Comp Sci, Nashville, TN 37235 USA.
EM alan.tipton@vanderbilt.edu
RI Pellish, Jonathan/A-8591-2008; Schrimpf, Ronald/L-5549-2013
OI Schrimpf, Ronald/0000-0001-7419-2701
FU NASA Electronic Parts; Threat Reduction Agency Radiation Hardened
Microelectronics Program [NNG06GI61G]
FX This work was supported in part by the NASA Electronic Parts and
Packaging Program and the Defense Threat Reduction Agency Radiation
Hardened Microelectronics Program under Contract IACRO #NNG06GI61G to
NASA.
NR 19
TC 28
Z9 31
U1 0
U2 14
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA
SN 0018-9499
J9 IEEE T NUCL SCI
JI IEEE Trans. Nucl. Sci.
PD DEC
PY 2008
VL 55
IS 6
BP 2880
EP 2885
DI 10.1109/TNS.2008.2006503
PG 6
WC Engineering, Electrical & Electronic; Nuclear Science & Technology
SC Engineering; Nuclear Science & Technology
GA 398DS
UT WOS:000262713400008
ER
PT J
AU Pellish, JA
Reed, RA
McMorrow, D
Melinger, JS
Jenkins, P
Sutton, AK
Diestelhorst, RM
Phillips, SD
Cressler, JD
Pouget, V
Pate, ND
Kozub, JA
Mendenhall, MH
Weller, RA
Schrimpf, RD
Marshall, PW
Tipton, AD
Niu, GF
AF Pellish, Jonathan A.
Reed, Robert A.
McMorrow, Dale
Melinger, Joseph S.
Jenkins, Phillip
Sutton, Akil K.
Diestelhorst, Ryan M.
Phillips, Stanley D.
Cressler, John D.
Pouget, Vincent
Pate, Nicholas D.
Kozub, John A.
Mendenhall, Marcus H.
Weller, Robert A.
Schrimpf, Ronald D.
Marshall, Paul W.
Tipton, Alan D.
Niu, Guofu
TI Laser-Induced Current Transients in Silicon-Germanium HBTs
SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE
LA English
DT Article
DE Current transient; electrostatic potential modulation; SiGe HBT;
two-photon absorption
ID HETEROJUNCTION BIPOLAR-TRANSISTORS; INDUCED CHARGE COLLECTION;
HEAVY-ION; PULSED-LASER; PROTON IRRADIATION; BICMOS TECHNOLOGY; SHIFT
REGISTERS; SIGE; DEVICES; CIRCUIT
AB Device-level current transients are induced by injecting carriers using two-photon absorption from a subbandgap pulsed laser and recorded using wideband transmission and measurement equipment. These transients exhibit three distinct temporal trends that depend on laser pulse energy as well as the transverse and vertical charge generation location. The nature of the current transient is controlled by both the behavior of the subcollector-substrate junction and isolation biasing. However, substrate potential modulation, due to deformation of the subcollector-substrate depletion region, is the dominant mechanism affecting transient characteristics.
C1 [Pellish, Jonathan A.; Reed, Robert A.; Pate, Nicholas D.; Weller, Robert A.; Schrimpf, Ronald D.; Tipton, Alan D.] Vanderbilt Univ, Dept Elect Engn & Comp Sci, Nashville, TN 37203 USA.
[McMorrow, Dale; Melinger, Joseph S.; Jenkins, Phillip] USN, Res Lab, Washington, DC 20375 USA.
[Sutton, Akil K.; Diestelhorst, Ryan M.; Phillips, Stanley D.; Cressler, John D.] Georgia Inst Technol, Sch Elect & Comp Engn, Atlanta, GA 30332 USA.
[Pouget, Vincent] Univ Bordeaux, Talence, France.
[Kozub, John A.] Vanderbilt Univ, Free Elect Laser Ctr, Nashville, TN USA.
[Mendenhall, Marcus H.] Vanderbilt Univ, Inst Space & Def Elect, Nashville, TN 37203 USA.
[Marshall, Paul W.] NASA, Brookneal, VA 24528 USA.
[Niu, Guofu] Auburn Univ, Dept Elect & Comp Engn, Auburn, AL 36849 USA.
RP Pellish, JA (reprint author), Vanderbilt Univ, Dept Elect Engn & Comp Sci, Nashville, TN 37203 USA.
EM jonathan.pel-lish@ieee.org
RI Pellish, Jonathan/A-8591-2008; Schrimpf, Ronald/L-5549-2013
OI Schrimpf, Ronald/0000-0001-7419-2701
FU NASA Electronic Parts and Packaging Program; Defense Threat Reduction
Agency Radiation Hardened Microelectronics Program [08-43431]; Georgia
Electronic Design Center at the Georgia Institute of Technology
FX This work was supported in part by the NASA Electronic Parts and
Packaging Program, the Defense Threat Reduction Agency Radiation
Hardened Microelectronics Program under IACRO #08-43431 to NASA, and the
Georgia Electronic Design Center at the Georgia Institute of Technology.
NR 40
TC 18
Z9 18
U1 2
U2 9
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA
SN 0018-9499
EI 1558-1578
J9 IEEE T NUCL SCI
JI IEEE Trans. Nucl. Sci.
PD DEC
PY 2008
VL 55
IS 6
BP 2936
EP 2942
DI 10.1109/TNS.2008.2007954
PN 1
PG 7
WC Engineering, Electrical & Electronic; Nuclear Science & Technology
SC Engineering; Nuclear Science & Technology
GA 398DS
UT WOS:000262713400015
ER
PT J
AU Black, JD
Ball, DR
Robinson, WH
Fleetwood, DM
Schrimpf, RD
Reed, RA
Black, DA
Warren, KM
Tipton, AD
Dodd, PE
Haddad, NF
Xapsos, MA
Kim, HS
Friendlich, M
AF Black, J. D.
Ball, D. R., II
Robinson, W. H.
Fleetwood, D. M.
Schrimpf, R. D.
Reed, R. A.
Black, D. A.
Warren, K. M.
Tipton, A. D.
Dodd, P. E.
Haddad, N. F.
Xapsos, M. A.
Kim, H. S.
Friendlich, M.
TI Characterizing SRAM Single Event Upset in Terms of Single and Multiple
Node Charge Collection
SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE
LA English
DT Article
DE Heavy ion testing; multiple cell upset; single event modeling; SRAM
ID INDUCED SOFT ERRORS; CMOS SRAMS; BIT UPSET; SIMULATION; RADIATION;
DEVICES; MODEL; SEU
AB A well-collapse source-injection mode for SRAM SEU is demonstrated through TCAD modeling. The recovery of the SRAM's state is shown to be based upon the resistive path from the p+-sources in the SRAM to the well. Multiple cell upset patterns for direct charge collection and the well-collapse source-injection mechanisms are predicted and compared to SRAM test data.
C1 [Black, J. D.; Ball, D. R., II; Warren, K. M.] Vanderbilt Univ, Inst Space & Def Elect, Nashville, TN 37203 USA.
[Robinson, W. H.; Fleetwood, D. M.; Schrimpf, R. D.; Reed, R. A.; Tipton, A. D.] Vanderbilt Univ, Dept Elect Engn & Comp Sci, Nashville, TN 37235 USA.
[Black, D. A.] Vanderbilt Univ, Off Dean, Sch Engn, Nashville, TN 37235 USA.
[Dodd, P. E.] Sandia Natl Labs, Albuquerque, NM 87185 USA.
[Haddad, N. F.] BAE Syst, Manassas, VA 20110 USA.
[Xapsos, M. A.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
[Kim, H. S.; Friendlich, M.] MEI Technol, Greenbelt, MD 20771 USA.
RP Black, JD (reprint author), Vanderbilt Univ, Inst Space & Def Elect, Nashville, TN 37203 USA.
EM jeffrey.d.black@vanderbilt.edu
RI Schrimpf, Ronald/L-5549-2013
OI Schrimpf, Ronald/0000-0001-7419-2701
FU NASA Electronic Parts and Packaging Program; Defense Threat Re-duction
Agency Radiation Hardened Microelectronics Program [NNG06GI61G]; United
States Department of Energy; Defense Threat Reduction Agency [08-43421];
[DE-AC04-94AL85000]
FX This work was supported in part by the NASA Electronic Parts and
Packaging Program and the Defense Threat Re-duction Agency Radiation
Hardened Microelectronics Program under contract IACI 6 #NNG06GI61G to
NASA. This work was supported by the United States Department of Energy
and the Defense Threat Reduction Agency under DTRA IACRO #08-43421.
Sandia is a multiprogram laboratory operated by Sandia Corporation, a
Lockheed Martin Company, for the United States Department of Energy's
National Nuclear Security Administration under Contract
DE-AC04-94AL85000.
NR 15
TC 44
Z9 47
U1 0
U2 4
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA
SN 0018-9499
J9 IEEE T NUCL SCI
JI IEEE Trans. Nucl. Sci.
PD DEC
PY 2008
VL 55
IS 6
BP 2943
EP 2947
DI 10.1109/TNS.2008.2007231
PG 5
WC Engineering, Electrical & Electronic; Nuclear Science & Technology
SC Engineering; Nuclear Science & Technology
GA 398DS
UT WOS:000262713400016
ER
PT J
AU Foster, CC
O'Neill, PM
Kouba, CK
AF Foster, Charles C.
O'Neill, Patrick M.
Kouba, Coy K.
TI Risk Assessment Based on Upset Rates From High Energy Proton Tests and
Monte Carlo Simulations
SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE
LA English
DT Article
DE Heavy ions; Monte Carlo methods; nuclear radiation effects; proton
radiation effects
ID HEAVY-IONS; CROSS-SECTIONS; SEU; MODEL
AB LEO upset rates and bounds due to heavy ion cosmic rays are assessed from 200 MeV proton tests using Monte Carlo simulations of energy deposition distributions in sensitive volumes of 26 parts.
C1 [Foster, Charles C.] Indiana Univ, Cyclotron Facil, Radiat Effects Res Program, Bloomington, IN 47408 USA.
[O'Neill, Patrick M.; Kouba, Coy K.] NASA, Lyndon B Johnson Space Ctr, Avion Syst Div, Houston, TX 77058 USA.
RP Foster, CC (reprint author), Foster Consulting Serv LLC, Univ Pl, WA 98466 USA.
EM fosterchc@nventure.com; patrick.m.oneill@nasa.gov; coy.kouba-1@nasa.gov
FU NASA Electronic Parts & Packaging Program (NEPP); NASA-JSC Engineering
Directorate; Space Station and International Spac Station Program
Offices
FX This work was supported in part by the NASA Electronic Parts & Packaging
Program (NEPP), the NASA-JSC Engineering Directorate, and the Space
Station and International Spac Station Program Offices.
NR 25
TC 3
Z9 3
U1 0
U2 6
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA
SN 0018-9499
J9 IEEE T NUCL SCI
JI IEEE Trans. Nucl. Sci.
PD DEC
PY 2008
VL 55
IS 6
BP 2962
EP 2969
DI 10.1109/TNS.2008.2008185
PG 8
WC Engineering, Electrical & Electronic; Nuclear Science & Technology
SC Engineering; Nuclear Science & Technology
GA 398DS
UT WOS:000262713400019
ER
PT J
AU Chen, XJ
Barnaby, HJ
Vertneire, B
Holbert, KE
Wright, D
Pease, RL
Schrimpf, RD
Fleetwood, DM
Pantelides, ST
Shaneyfelt, MR
Adell, P
AF Chen, X. Jie
Barnaby, Hugh J.
Vertneire, Bert
Holbert, Keith E.
Wright, David
Pease, Ronald L.
Schrimpf, Ronald D.
Fleetwood, Daniel M.
Pantelides, Sokrates T.
Shaneyfelt, Marty R.
Adell, Philippe
TI Post-Irradiation Annealing Mechanisms of Defects Generated in
Hydrogenated Bipolar Oxides
SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE
LA English
DT Article
DE Bipolar oxide; gated bipolar devices; interface traps; hydrogen; oxide
trapped charge; radiation-induced
ID DOSE-RATE SENSITIVITY; INTERFACE-TRAP FORMATION; FIELD-EFFECT
TRANSISTORS; ENERGY-DISTRIBUTION; MOS DEVICES; CHARGE; ENVIRONMENTS;
DEGRADATION; PREDICTION; CIRCUITS
AB Bipolar test structures were irradiated and annealed with various combinations of molecular hydrogen gas ambients, bias, and thermal conditions. The results show that the buildup and annealing behavior of defects in bipolar base oxides depend strongly on hydrogen concentration. Differences observed in trapped oxide charge annealing rates suggest that the charged defects created in hydrogen-rich environments may be attributed to different types of positive charge in addition to trapped holes.
C1 [Chen, X. Jie; Barnaby, Hugh J.; Vertneire, Bert; Holbert, Keith E.; Wright, David] Arizona State Univ, Tempe, AZ 85287 USA.
[Pease, Ronald L.] RLP Res, Los Lunas, NM 87031 USA.
[Schrimpf, Ronald D.; Fleetwood, Daniel M.; Pantelides, Sokrates T.] Vanderbilt Univ, Nashville, TN 37235 USA.
[Shaneyfelt, Marty R.] Sandia Natl Labs, Albuquerque, NM 87185 USA.
[Adell, Philippe] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Chen, XJ (reprint author), Arizona State Univ, Tempe, AZ 85287 USA.
EM j.chen@asu.edu; rpease@rlpresearch.com; ron.schimpf@vanderbilt.edu;
dan.fleetwood@vanderbilt.edu; pantelides@vanderbilt.edu;
shaneymr@sandia.gov; philippe.c.adell@jpl.nasa.gov
RI Holbert, Keith/B-6518-2008; Schrimpf, Ronald/L-5549-2013;
OI Schrimpf, Ronald/0000-0001-7419-2701; Holbert, Keith/0000-0002-2772-1954
FU NASA's Jet Propulsion Laboratory with funding from the NASA Electronics
Parts Program (NEPP); Air Force Office of Scientific Research with
funding from the MURI program; United States Department of Energy
[DE-AC04-94AL85000]
FX Manuscript received July 11, 2008; revised September 09, 2008. Current
version published December 31, 2008. This work is supported by NASA's
Jet Propulsion Laboratory with funding from the NASA Electronics Parts
Program (NEPP), and the Air Force Office of Scientific Research with
funding from the MURI program. This work is also supported by the United
States Department of Energy. Sandia is a multiprogram laboratory
operated by Sandia Corporation a Lockheed Martin Company, for the United
States Department of Energy's National Nuclear Security Administration
under Contract DE-AC04-94AL85000.
NR 38
TC 7
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U1 3
U2 14
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA
SN 0018-9499
J9 IEEE T NUCL SCI
JI IEEE Trans. Nucl. Sci.
PD DEC
PY 2008
VL 55
IS 6
BP 3032
EP 3038
DI 10.1109/TNS.2008.2006972
PG 7
WC Engineering, Electrical & Electronic; Nuclear Science & Technology
SC Engineering; Nuclear Science & Technology
GA 398DS
UT WOS:000262713400029
ER
PT J
AU Harris, RD
McClure, SS
Rax, BG
Evans, RW
Jun, I
AF Harris, Richard D.
McClure, Steven S.
Rax, Bernard G.
Evans, Robin W.
Jun, Insoo
TI Comparison of TID Effects in Space-Like Variable Dose Rates and Constant
Dose Rates
SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE
LA English
DT Article
DE Dose rate; ELDRS; LM193; solar flare; TID
ID CIRCUITS
AB The degradation of the LM193 dual voltage comparator has been studied at different TID dose rate profiles, including several different constant dose rates and a variable dose rate that simulates the behavior of a solar flare. A comparison of results following constant dose rate vs. variable dose rates is made to explore how well the constant dose rates used for typical part testing predict the performance during a simulated space-like mission. Testing at a constant dose rate equal to the lowest dose rate seen during the simulated flare provides an extremely conservative estimate of the overall amount of degradation. A constant dose rate equal to the average dose rate is also more conservative than the variable rate. It appears that, for this part, weighting the dose rates by the amount of total dose received at each rate (rather than the amount of time at each dose rate) results in an average rate that produces an amount of degradation that is a reasonable approximation to that received by the variable rate.
C1 [Harris, Richard D.; McClure, Steven S.; Rax, Bernard G.; Evans, Robin W.; Jun, Insoo] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Harris, RD (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM richard.d.harris@jpl.nasa.gov; steven.s.mcclure@jpl.nasa.gov;
bernard.g.rax@jpl.nasa.gov; robin.w.evans@jpl.nasa.gov;
insoo.jun@jpl.nasa.gov
FU NASA Electronics Parts and Packaging Program (NEPP)
FX Manuscript received July 11, 2008; revised September 16, 2008. Current
version published December 31, 2008. This work was carried out at the
Jet Propulsion Laboratory, California Institute of Technology, Pasadena,
CA, under contract with the National Aeronautics and Space
Administration (NASA) with funding from the NASA Electronics Parts and
Packaging Program (NEPP).
NR 12
TC 6
Z9 8
U1 0
U2 5
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA
SN 0018-9499
J9 IEEE T NUCL SCI
JI IEEE Trans. Nucl. Sci.
PD DEC
PY 2008
VL 55
IS 6
BP 3088
EP 3095
DI 10.1109/TNS.2008.2006970
PG 8
WC Engineering, Electrical & Electronic; Nuclear Science & Technology
SC Engineering; Nuclear Science & Technology
GA 398DS
UT WOS:000262713400037
ER
PT J
AU Balasubramanian, A
Bhuva, BL
Massengill, LW
Narasimham, B
Shuler, RL
Loveless, TD
Holman, WT
AF Balasubramanian, Anitha
Bhuva, B. L.
Massengill, L. W.
Narasimham, B.
Shuler, R. L.
Loveless, T. D.
Holman, W. Timothy
TI A Built-In Self-Test (BIST) Technique for Single-Event Testing in
Digital Circuits
SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE
LA English
DT Article
DE Current-starved inverters; digital circuits; random number generator;
single-events; single-event transients
ID TRANSIENT PULSEWIDTHS; COMBINATIONAL LOGIC; SIMULATION
AB A built-in self-test technique for testing digital logic circuits for single-events has been developed. The BIST technique can be used for single-event testing in any conventional laboratory to evaluate the circuit level response to SEs. Experimental and simulation results for multiple technology nodes show the feasibility of this approach to test circuits, with the added advantages of reduced testing time and cost.
C1 [Balasubramanian, Anitha; Bhuva, B. L.; Massengill, L. W.; Narasimham, B.; Loveless, T. D.; Holman, W. Timothy] Vanderbilt Univ, Dept Elect Engn & Comp Sci, Nashville, TN 37235 USA.
[Shuler, R. L.] NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA.
RP Balasubramanian, A (reprint author), Vanderbilt Univ, Dept Elect Engn & Comp Sci, 221 Kirkland Hall, Nashville, TN 37235 USA.
EM balasubramanian.anitha@gmail.com; bharat.l.bhuva@vander-bilt.edu;
lloyd.messengill@vanderbilt.edu; balaji.narasimham@vanderbilt.edu;
robert.l.shuler@nasa.gov; danie1.loveless@vanderbilt.edu;
holmanwt@vuse.vanderbilt.edu
RI Loveless, Thomas/G-9420-2011; Loveless, Thomas/C-7132-2016
FU Defense Threat Reduction Agency
FX Manuscript received July 11. 2008 revised August 30, 2008. Current
version published December 31, 2008. This work was supported in part by
the Defense Threat Reduction Agency.
NR 21
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U1 0
U2 2
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA
SN 0018-9499
EI 1558-1578
J9 IEEE T NUCL SCI
JI IEEE Trans. Nucl. Sci.
PD DEC
PY 2008
VL 55
IS 6
BP 3130
EP 3135
DI 10.1109/TNS.2008.2006499
PN 1
PG 6
WC Engineering, Electrical & Electronic; Nuclear Science & Technology
SC Engineering; Nuclear Science & Technology
GA 398DS
UT WOS:000262713400042
ER
PT J
AU Kim, W
Jun, I
Garrett, HB
AF Kim, Wousik
Jun, Insoo
Garrett, Henry B.
TI An Algorithm for Determining Energy Deposition Profiles in Elemental
Slabs by Low (< 100 keV) Energy Electrons: An Internal Charging
Application
SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE
LA English
DT Article
DE Dose profile; NUMIT; TIGER/ITS3
AB Internal charging/discharging is an important concern for today's spacecraft. An important tool for tracking charge buildup in slabs of material that includes a self-consistent solution of the electric fields in the material is the NUMIT code. To date, one of limitations on use of that code has been determining the effects for particles with energy less than 100 keV. To correct this, a universal algorithm for determining dose profiles in slabs has been developed for low energy (10 keV <= E(i) <= 100 keV) electrons. This work extends the Tabata algorithm, originally developed for E(i) > 100 keV electrons, down to 10 keV. Following a brief review of the NUMIT code, the role the Tabata algorithm plays in NUMIT is discussed. As a first step in extending the algorithm, Monte Carlo simulations were performed to obtain the dose-depth profiles for various incident energies. It was found that for a given target, the dose profiles obtained for the different incident energies can be normalized to a single curve by applying the scaling factors for the depth (x-axis) and energy deposition (y-axis). These scaling factors are dependent both on the incident electron energy and on the target material. In the second step, for each target element, the normalized dose profile was fit with a simple equation and the fitting coefficients obtained. The overall fitting procedure and the parameters obtained for the fit are described in this paper.
C1 [Kim, Wousik; Jun, Insoo; Garrett, Henry B.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Kim, W (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM Wousik.Kim@jpl.nasa.gov; Insoo.Jun@jpl.nasa.gov;
Henry.B.Garrett@jpl.nasa.gov
FU National Aeronautics and Space Administration (NASA)
FX Manuscript received July 11, 2008 revised September 08. 2008. Current
version published December 31. 2008. This research was carried out at
the Jet Propulsion Laboratory, California Institute of Technology, and
supported by a contract with the National Aeronautics and Space
Administration (NASA).
NR 11
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U1 0
U2 2
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA
SN 0018-9499
J9 IEEE T NUCL SCI
JI IEEE Trans. Nucl. Sci.
PD DEC
PY 2008
VL 55
IS 6
BP 3158
EP 3163
DI 10.1109/TNS.2008.2009116
PG 6
WC Engineering, Electrical & Electronic; Nuclear Science & Technology
SC Engineering; Nuclear Science & Technology
GA 398DS
UT WOS:000262713400047
ER
PT J
AU Pease, RL
Adell, PC
Rax, BG
Chen, XJ
Barnaby, HJ
Holbert, KE
Hjalmarson, HP
AF Pease, Ronald L.
Adell, Philippe Claude
Rax, Bernard G.
Chen, Xiao Jie
Barnaby, Hugh J.
Holbert, Keith E.
Hjalmarson, Harold P.
TI The Effects of Hydrogen on the Enhanced Low Dose Rate Sensitivity
(ELDRS) of Bipolar Linear Circuits
SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE
LA English
DT Article
DE Dose rate; enhanced low-dose rate sensitivity; hydrogen; interface
traps; radiation effects; total ionizing dose; voltage comparator
ID RADIATION; TRANSISTORS; DEPENDENCE; MECHANISMS; ICS
AB It is experimentally demonstrated with test transistors and circuits that hydrogen is correlated with enhanced low dose rate sensitivity (ELDRS) in bipolar linear circuits. These experiments show that the amount of hydrogen determines the total dose response versus dose rate, both the saturation at low dose rate and the transition dose rate between the high and low dose rate responses. The experimental results are supported with modeling calculations using REOS (Radiation Effects in Oxides and Semiconductors).
C1 [Pease, Ronald L.] RLP Res, Los Lunas, NM 87031 USA.
[Adell, Philippe Claude; Rax, Bernard G.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[Chen, Xiao Jie; Barnaby, Hugh J.; Holbert, Keith E.] Arizona State Univ, Tempe, AZ 85287 USA.
[Hjalmarson, Harold P.] Sandia Natl Labs, Albuquerque, NM 87186 USA.
RP Pease, RL (reprint author), RLP Res, Los Lunas, NM 87031 USA.
EM rpease@rlpresearch.com; philippe.c.adell@jpl.nasa.gov;
bernard.g.rax@jpl.nasa.gov; j.chen@asu.edu; hbarnaby@asu.edu;
keith.holbert@asu.edu; hphjalm@sandia.gov
RI Holbert, Keith/B-6518-2008;
OI Holbert, Keith/0000-0002-2772-1954
FU Defense Threat Reduction Agency with NAVSEA Crane and ATK Mission
Research [N00164-02-D-6599]; NASA Electronic Parts Program; United
States Department of Energy's National Nuclear Security Administration
[DE-AC04-94AL85000]
FX Manuscript received July 11, 2008; revised August 23, 2008. Current
version published December 31, 2008. This work was supported in part by
the Defense Threat Reduction Agency through Contract N00164-02-D-6599
with NAVSEA Crane and ATK Mission Research and by the NASA Electronic
Parts Program. Sandia is a multiprogram laboratory operated by Sandia
Corporation, a Lockheed Martin Company, for the United States Department
of Energy's National Nuclear Security Administration under Contract
DE-AC04-94AL85000.
NR 20
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U1 0
U2 3
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA
SN 0018-9499
J9 IEEE T NUCL SCI
JI IEEE Trans. Nucl. Sci.
PD DEC
PY 2008
VL 55
IS 6
BP 3169
EP 3173
DI 10.1109/TNS.2008.2006478
PG 5
WC Engineering, Electrical & Electronic; Nuclear Science & Technology
SC Engineering; Nuclear Science & Technology
GA 398DS
UT WOS:000262713400049
ER
PT J
AU Bellini, M
Phillips, SD
Diestelhorst, RM
Cheng, P
Cressler, JD
Marshall, PW
Turowski, M
Avenier, G
Chantre, A
Chevalier, P
AF Bellini, Marco
Phillips, Stanley D.
Diestelhorst, Ryan M.
Cheng, Peng
Cressler, John D.
Marshall, Paul W.
Turowski, Marek
Avenier, Gregory
Chantre, Alain
Chevalier, Pascal
TI Novel Total Dose and Heavy-Ion Charge Collection Phenomena in a New SiGe
HBT on Thin-Film SOI Technology
SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE
LA English
DT Article
DE C-SiGe; Heterojunction bipolar transistors; radiation effects; SiGe HBT;
silicon-on-insulator (SOI); TCAD
ID CMOS-COMPATIBLE SOI
AB We investigate radiation-induced effects on the DC, AC and thermal characteristics of high-performance SiGe HBTs fabricated on thin-film SOL TCAD simulations indicate novel heavy-ion charge collection phenomena resulting from the unique C(B)E(B)C device layout of this technology platform.
C1 [Bellini, Marco; Phillips, Stanley D.; Diestelhorst, Ryan M.; Cheng, Peng; Cressler, John D.] Georgia Inst Technol, Sch Elect & Comp Engn, Atlanta, GA 30332 USA.
[Marshall, Paul W.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
[Turowski, Marek] CFD Res Corp, Huntsville, AL 35805 USA.
[Avenier, Gregory; Chantre, Alain; Chevalier, Pascal] STMicroelectronics, F-38926 Crolles, France.
RP Bellini, M (reprint author), Georgia Inst Technol, Sch Elect & Comp Engn, Atlanta, GA 30332 USA.
EM bellini@ece.gatech.edu; pwmarshall@aol.com; mt@cfdrc.com;
gregory.avenier@st.com; alain.chantre@st.com; pascal.chevalier@st.com
FU DTRA; NASA-GSFC; AFOSR MURI; CFDRC; STMicroelectronics
FX This work was supported in part by the DTRA under the Radiation Hardened
Microelectronics Program, NASA-GSFC under the NASA Electronic Parts and
Packaging (NEPP) program, an AFOSR MURI program, CFDRC (under a DTRA
SBIR), and in part by STMicroelectronics.
NR 14
TC 6
Z9 6
U1 6
U2 9
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA
SN 0018-9499
J9 IEEE T NUCL SCI
JI IEEE Trans. Nucl. Sci.
PD DEC
PY 2008
VL 55
IS 6
BP 3197
EP 3201
DI 10.1109/TNS.2008.2005108
PG 5
WC Engineering, Electrical & Electronic; Nuclear Science & Technology
SC Engineering; Nuclear Science & Technology
GA 398DS
UT WOS:000262713400053
ER
PT J
AU Thrivikraman, TK
Cheng, P
Phillips, SD
Comeau, JP
Morton, MA
Cressler, JD
Papapolymerou, J
Marshall, PW
AF Thrivikraman, Tushar K.
Cheng, Peng
Phillips, Stanley D.
Comeau, Jonathan P.
Morton, Matt A.
Cressler, John D.
Papapolymerou, John
Marshall, Paul W.
TI On the Radiation Tolerance of SiGe HBT and CMOS-Based Phase Shifters for
Space-Based, Phased-Array Antenna Systems
SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE
LA English
DT Article
DE CMOS; phased-array; phase-shifters; radar; radiation response;
silicon-germanium HBT; single-pole double throw switch
ID TECHNOLOGY; SILICON; RF
AB We report the first irradiation results on high-frequency SiGe HBT and CMOS phase shifters for space- based, phased-array antennas used in radar or wireless communication systems. Both phase shifter circuits remain functional with acceptable dc and RF performance up to multi-Mrad proton exposure, and are thus suitable for many orbital applications. In addition, simulation results probing the limits of phase shifter performance in a radiation environment are presented. These results show that both CMOS and SiGe HBT based phase shifters can be used for space-based applications without any specific radiation hardening techniques.
C1 [Thrivikraman, Tushar K.; Cheng, Peng; Phillips, Stanley D.; Comeau, Jonathan P.; Morton, Matt A.; Cressler, John D.; Papapolymerou, John] Georgia Inst Technol, Sch Elect & Comp Engn, Atlanta, GA 30308 USA.
[Marshall, Paul W.] NASA, Brookneal, VA 24528 USA.
RP Thrivikraman, TK (reprint author), Georgia Inst Technol, Sch Elect & Comp Engn, Atlanta, GA 30308 USA.
EM tthrivi@ece.gatech.edu
FU NASA [NNX08AN22G]; DTRA; NASA-GSFC under the NASA Electronic Parts and
Packaging (NEPP); AFOSR MURI; GTRI IRAD
FX This work was supported in part by NASA under Contract NNX08AN22G, in
part by DTRA under the Radiation Hardened Microelectronics Program, in
part by NASA-GSFC under the NASA Electronic Parts and Packaging (NEPP)
program, in part by an AFOSR MURI program. and in part by a GTRI IRAD
project.
NR 18
TC 4
Z9 4
U1 1
U2 4
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA
SN 0018-9499
J9 IEEE T NUCL SCI
JI IEEE Trans. Nucl. Sci.
PD DEC
PY 2008
VL 55
IS 6
BP 3246
EP 3252
DI 10.1109/TNS.2008.2006968
PG 7
WC Engineering, Electrical & Electronic; Nuclear Science & Technology
SC Engineering; Nuclear Science & Technology
GA 398DS
UT WOS:000262713400060
ER
PT J
AU Najafizadeh, L
Vo, T
Phillips, SD
Cheng, P
Wilcox, EP
Cressler, JD
Mojarradi, M
Marshall, PW
AF Najafizadeh, Laleh
Vo, Tuan
Phillips, Stanley D.
Cheng, Peng
Wilcox, Edward P.
Cressler, John D.
Mojarradi, Mohammad
Marshall, Paul W.
TI The Effects of Proton Irradiation on the Performance of High-Voltage
n-MOSFETs Implemented in a Low-Voltage SiGe BiCMOS Platform
SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE
LA English
DT Article
DE High-voltage CMOS transistors; ionization damage; MOSFET; SiGe; total
dose radiation effects
ID TRANSISTORS; TECHNOLOGY; LEAKAGE; DESIGN
AB This paper presents the first comprehensive investigation of the impact of proton irradiation on the performance of high-voltage (HV) nMOS transistors implemented in a low-voltage (LV) SiGe BiCMOS technology. The effects of irradiation gate bias, irradiation substrate bias, and operating substrate bias on the radiation response of these transistors are examined. Experimental results show that the radiation-induced subthreshold leakage current under different irradiation biasing conditions remains negligible after exposure to a total dose of 600 krad(Si). We find that there are differences in the radiation response of LV and HV MOSFETs, suggesting that the mechanisms involved in causing degradation in LV and HV transistors could be of fundamentally different origins.
C1 [Najafizadeh, Laleh; Phillips, Stanley D.; Cheng, Peng; Wilcox, Edward P.; Cressler, John D.] Georgia Inst Technol, Sch Elect & Comp Engn, Atlanta, GA 30332 USA.
[Vo, Tuan; Mojarradi, Mohammad] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[Marshall, Paul W.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
RP Najafizadeh, L (reprint author), Georgia Inst Technol, Sch Elect & Comp Engn, Atlanta, GA 30332 USA.
EM laleh@ece.gatech.edu; Tuan.A.Vo@jpl.nasa.gov; stan.phillips@gatech.edu;
pcheng@ece.gatech.edu; twilcox@ece.gatech.edu; cressler@ece.gatech.edu;
mohammad.m.mojarradi@jpl.nasa.gov; pwmarshall@aol.com
FU Defense Threat Reduction Agency; NASA-GSFC; NASA SiGe ETDP; AFOSR MURI;
Georgia Electronic Design Center at Georgia Tech
FX This work was supported by the Defense Threat Reduction Agency under the
Radiation Hardened Microelectronics Program, NASA-GSFC under the NASA
Electronic Parts and Packaging (NEPP) program, the NASA SiGe ETDP
program, an AFOSR MURI program, and the Georgia Electronic Design Center
at Georgia Tech.
NR 22
TC 2
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U1 0
U2 2
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA
SN 0018-9499
J9 IEEE T NUCL SCI
JI IEEE Trans. Nucl. Sci.
PD DEC
PY 2008
VL 55
IS 6
BP 3253
EP 3258
DI 10.1109/TNS.2008.2007120
PG 6
WC Engineering, Electrical & Electronic; Nuclear Science & Technology
SC Engineering; Nuclear Science & Technology
GA 398DS
UT WOS:000262713400061
ER
PT J
AU Edmonds, LD
Scheick, LZ
AF Edmonds, L. D.
Scheick, L. Z.
TI Physical Mechanisms of Ion-Induced Stuck Bits in the Hyundai 16M x 4
SDRAM
SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE
LA English
DT Article
DE Displacement damage; single event effects
ID HEAVY-IONS; PROTONS; NIEL
AB It was previously thought that stuck bits in the Hyundai 16M x 4 SDRAM were caused by micro-dose. It is argued here that the correct mechanism is micro (i.e., from a single particle hit) displacement damage, which creates a leakage current that drains the storage capacitor.
C1 [Edmonds, L. D.; Scheick, L. Z.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Edmonds, LD (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM larry.d.edmonds@jpl.nasa.gov; leif.z.scheick@jpl.nasa.gov
FU National Aeronautics and Space Administration
FX This work was carried out at the Jet Propulsion Laboratory, California
Institute of Technology, under a contract with the National Aeronautics
and Space Administration. Reference herein to any specific commercial
product, process, or service by trade name, trademark, manufacturer, or
otherwise, does not constitute or imply its endorsement by the United
States Government or the Jet Propulsion Laboratory, California Institute
of Technology.
NR 13
TC 11
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U1 0
U2 3
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA
SN 0018-9499
J9 IEEE T NUCL SCI
JI IEEE Trans. Nucl. Sci.
PD DEC
PY 2008
VL 55
IS 6
BP 3265
EP 3271
DI 10.1109/TNS.2008.2006902
PG 7
WC Engineering, Electrical & Electronic; Nuclear Science & Technology
SC Engineering; Nuclear Science & Technology
GA 398DS
UT WOS:000262713400063
ER
PT J
AU Irom, F
Miyahira, TF
Adel, PC
Laird, JS
Conder, B
Pouget, V
Essely, F
AF Irom, Farokh
Miyahira, Tetsuo F.
Adel, Philippe C.
Laird, Jamie S.
Conder, Brandon
Pouget, Vincent
Essely, Fabien
TI Investigation of Single-Event Transients in Linear Voltage Regulators
SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE
LA English
DT Article
DE Laser; radiation testing; single-event transient; voltage regulator
ID INTEGRATED-CIRCUITS; LASER
AB Single-event transients (SETs) from heavy ions and laser beam are investigated for two positive adjustable linear voltage regulators: the RH117 from Linear Technology and the HS-117RH from Intersil. Both positive and negative going transients are observed. The role of input voltage, load capacitance and supply current on the SET response is discussed.
C1 [Irom, Farokh; Miyahira, Tetsuo F.; Adel, Philippe C.; Laird, Jamie S.; Conder, Brandon] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[Pouget, Vincent; Essely, Fabien] Univ Bordeaux, F-33405 Talence, France.
RP Irom, F (reprint author), CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
EM farokh.irom@jpl.nasa.gov; tetsuo.f.miyahira@jpl.nasa.gov;
philippe.c.adell@jpl.nasa.gov; Jamie.s.laird@jpl.nasa.gov;
Brandon.Conder@jpl.nasa.gov; vincent.pouget@ims-bordeaux.fr;
Fabien.essely@ims-bordeaux.fr
RI Laird, Jamie/A-7683-2011
NR 13
TC 7
Z9 7
U1 0
U2 1
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA
SN 0018-9499
J9 IEEE T NUCL SCI
JI IEEE Trans. Nucl. Sci.
PD DEC
PY 2008
VL 55
IS 6
BP 3352
EP 3359
DI 10.1109/TNS.2008.2007800
PG 8
WC Engineering, Electrical & Electronic; Nuclear Science & Technology
SC Engineering; Nuclear Science & Technology
GA 398DS
UT WOS:000262713400076
ER
PT J
AU Wei, XY
Zhang, T
Niu, GF
Varadharajaperumal, M
Cressler, JD
Marshall, PW
AF Wei, Xiaoyun
Zhang, Tong
Niu, Guofu
Varadharajaperumal, Muthubalan
Cressler, John D.
Marshall, Paul W.
TI 3-D Mixed-Mode Simulation of Single Event Transients in SiGe HBT Emitter
Followers and Resultant Hardening Guidelines
SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE
LA English
DT Article
DE Charge collection; heterojunction bipolar transistors; radiation
hardening by design; single event effects; single event transients
ID INDUCED CHARGE COLLECTION; SEE
AB This work presents 3-D mixed-mode simulation results of single event transients (SET) in SiGe HBT emitter followers. The impact of circuit design parameters, including biasing current and resistance are detailed. A simple increase of biasing emitter current is shown to be ineffective for hardening. Instead, during SET, the emitter voltage upset simply follows the base voltage upset due to the inherent nature of the emitter follower topology during circuit operation. The duration and the peak value of the base voltage upset are determined by the impedance and electric field between collector and base. As a result, the use of a smaller base biasing resistance is desirable for reducing SETs in emitter followers.
C1 [Wei, Xiaoyun; Zhang, Tong; Niu, Guofu; Varadharajaperumal, Muthubalan] Auburn Univ, Dept Elect & Comp Engn, Auburn, AL 36849 USA.
[Cressler, John D.] Georgia Inst Technol, Sch Elect & Comp Engn, Atlanta, GA 30332 USA.
[Marshall, Paul W.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
RP Wei, XY (reprint author), Auburn Univ, Dept Elect & Comp Engn, Auburn, AL 36849 USA.
EM weixiao@auburn.edu; zhangto@auburn.edu; ni-uguof@auburn.edu;
varadmu@auburn.edu; cressler@ece.gatech.edu; pwmarshall@aol.com
FU NASA-GSFC; DTRA; NASA ETDP
FX This work was supported by NASA-GSFC under NASA Electronic Parts,
Packaging Program and DTRA under the Radiation Hardened Microelectronics
Program, and the NASA ETDP Program.
NR 10
TC 9
Z9 9
U1 0
U2 2
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA
SN 0018-9499
J9 IEEE T NUCL SCI
JI IEEE Trans. Nucl. Sci.
PD DEC
PY 2008
VL 55
IS 6
BP 3360
EP 3366
DI 10.1109/TNS.2008.2006840
PG 7
WC Engineering, Electrical & Electronic; Nuclear Science & Technology
SC Engineering; Nuclear Science & Technology
GA 398DS
UT WOS:000262713400077
ER
PT J
AU Heidel, DF
Marshall, PW
Label, KA
Schwank, JR
Rodbell, KP
Hakey, MC
Berg, MD
Dodd, PE
Friendlich, MR
Phan, AD
Seidleck, CM
Shaneyfelt, MR
Xapsos, MA
AF Heidel, David F.
Marshall, Paul W.
LaBel, Kenneth A.
Schwank, James R.
Rodbell, Kenneth P.
Hakey, Mark C.
Berg, Melanie D.
Dodd, Paul E.
Friendlich, Mark R.
Phan, Anthony D.
Seidleck, Christina M.
Shaneyfelt, Marty R.
Xapsos, Michael A.
TI Low Energy Proton Single-Event-Upset Test Results on 65 nm SOI SRAM
SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE
LA English
DT Article
DE Proton irradiation; silicon-on-insulator (SOI) technology; single event
upset (SEU); SRAM
AB Experimental results are presented on proton induced single-event-upsets (SEU) on a 65 nm silicon-on-insulator (SOI) SRAM. The low energy proton SEU results are very different for the 65 nm SRAM as compared with SRAMs fabricated in previous technology generations. Specifically, no upset threshold is observed as the proton energy is decreased down to 1 MeV; and a sharp rise in the upset cross-section is observed below 1 MeV. The increase below 1 MeV is attributed to upsets caused by direct ionization from the low energy protons. The implications of the low energy proton upsets are discussed for space applications of 65 nm SRAMs; and the implications for radiation assurance testing are also discussed.
C1 [Heidel, David F.; Rodbell, Kenneth P.] IBM Corp, Thomas J Watson Res Ctr, Yorktown Hts, NY 10598 USA.
[Marshall, Paul W.] NASA, Brookneal, VA 24528 USA.
[LaBel, Kenneth A.; Xapsos, Michael A.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
[Schwank, James R.; Dodd, Paul E.; Shaneyfelt, Marty R.] Sandia Natl Labs, Albuquerque, NM 87175 USA.
[Hakey, Mark C.] IBM Syst & Technol Grp, Essex Jct, VT 05452 USA.
[Berg, Melanie D.; Friendlich, Mark R.; Phan, Anthony D.; Seidleck, Christina M.] MEI Technol, Greenbelt, MD 20771 USA.
RP Heidel, DF (reprint author), IBM Corp, Thomas J Watson Res Ctr, Yorktown Hts, NY 10598 USA.
EM heidel@us.ibm.com; pwmar-shall@aol.com; kenneth.a.label@nasa.gov;
schwanjr@sandia.gov; rodbell@us.ibm.com; mhakey@us.ibm.com;
md-berg@pop500.gsfc.nasa.gov; pedodd@sandia.gov;
mark.r.friendlich.1@gsfc.nasa.gov; an-thony.d.phan.1@gsfc.nasa.gov;
christina.m.seidleck.1@gsfc.nasa.gov; shaneymr@sandia.gov;
michael.a.xapsos@nasa.gov
FU NASA Electronic and Parts Packaging Program; Defense Threat Reduction
Agency; U.S. Department of Energy; United States Department of Energy's
National Nuclear Security Administration [DE-AC04-94AL85000]
FX This work was supported in part by the NASA Electronic and Parts
Packaging Program, by the Defense Threat Reduction Agency, and by the
U.S. Department of Energy. Sandia is a multi-program laboratory operated
by Sandia Corporation, a Lockheed Martin Company, for the United States
Department of Energy's National Nuclear Security Administration under
Contract DE-AC04-94AL85000.
NR 13
TC 71
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U1 1
U2 11
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA
SN 0018-9499
J9 IEEE T NUCL SCI
JI IEEE Trans. Nucl. Sci.
PD DEC
PY 2008
VL 55
IS 6
BP 3394
EP 3400
DI 10.1109/TNS.2008.2005499
PG 7
WC Engineering, Electrical & Electronic; Nuclear Science & Technology
SC Engineering; Nuclear Science & Technology
GA 398DS
UT WOS:000262713400082
ER
PT J
AU Narasimham, B
Gambles, JW
Shuler, RL
Bhuva, BL
Massengill, LW
AF Narasimham, Balaji
Gambles, Jody W.
Shuler, Robert L.
Bhuva, Bharat L.
Massengill, Lloyd W.
TI Quantifying the Effect of Guard Rings and Guard Drains in Mitigating
Charge Collection and Charge Spread
SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE
LA English
DT Article
DE Collected charge; guard drain; guard ring; pulse width; single event;
Single-Event Transient (SET)
ID 130 NM; SINGLE
AB 3D-TCAD simulations in a 130-nm process are used to show the effect of guard rings and guard drains in mitigating charge collection and charge sharing between nodes. Experimental results quantifying the reduction in SET pulse width and the error cross section were obtained with the use of SET pulse width and SET error rate measurement test circuits fabricated in 130-nm and 180-nm processes. Results indicate that guard drains results in 30% lower error cross section compared to guard ring circuits.
C1 [Narasimham, Balaji; Bhuva, Bharat L.; Massengill, Lloyd W.] Vanderbilt Univ, Nashville, TN 37235 USA.
[Gambles, Jody W.] Univ Idaho, Ctr Adv Microelect & Biomol Res, Post Falls, ID 83854 USA.
[Shuler, Robert L.] NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA.
RP Narasimham, B (reprint author), Vanderbilt Univ, Nashville, TN 37235 USA.
EM balaji.narasimham@vanderbilt.edu; jgambles@excite.com;
robert.l.shuler@nasa.gov; bharat.l.bhuva@vanderbilt.edu;
lloyd.massengill@vanderbilt.edu
FU DTRA Rad-Hard Microelectronics Program
FX This work was supported in part by the DTRA Rad-Hard Microelectronics
Program.
NR 11
TC 32
Z9 37
U1 0
U2 3
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA
SN 0018-9499
J9 IEEE T NUCL SCI
JI IEEE Trans. Nucl. Sci.
PD DEC
PY 2008
VL 55
IS 6
BP 3456
EP 3460
DI 10.1109/TNS.2008.2007119
PG 5
WC Engineering, Electrical & Electronic; Nuclear Science & Technology
SC Engineering; Nuclear Science & Technology
GA 398DS
UT WOS:000262713400091
ER
PT J
AU Harris, RD
Imaizumi, M
Walters, RJ
Lorentzen, JR
Messenger, SR
Tischler, JG
Ohshima, T
Sato, S
Sharps, PR
Fatemi, NS
AF Harris, R. D.
Imaizumi, M.
Walters, R. J.
Lorentzen, J. R.
Messenger, S. R.
Tischler, J. G.
Ohshima, T.
Sato, S.
Sharps, P. R.
Fatemi, N. S.
TI In Situ Irradiation and Measurement of Triple Junction Solar Cells at
Low Intensity, Low Temperature (LILT) Conditions
SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE
LA English
DT Article
DE LILT; quantum efficiency; radiation damage; space solar cells; triple
junction solar cells
AB The performance of triple junction InGaP/(In)GaAs/Ge space solar cells was studied following high energy electron irradiation at low temperature. Cell characterization was carried out in situ at the irradiation temperature while using low intensity illumination, and, as such, these conditions reflect those found for deep space, solar powered missions that are far from the sun. Cell characterization consisted of I-V measurements and quantum efficiency measurements. The low temperature irradiations caused substantial degradation that differs in some ways from that seen after room temperature irradiations. The short circuit current degrades more at low temperature while the open circuit voltage degrades more at room temperature. A room temperature anneal after the low temperature irradiation produced a substantial recovery in the degradation. Following irradiation at both temperatures and an extended room temperature anneal, quantum efficiency measurement suggests that the bulk of the remaining damage is in the (In)GaAs sub-cell.
C1 [Harris, R. D.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[Imaizumi, M.] Japan Aerosp Explorat Agcy, Tsukuba, Ibaraki, Japan.
[Walters, R. J.; Lorentzen, J. R.; Messenger, S. R.; Tischler, J. G.] USN, Res Lab, Washington, DC 20375 USA.
[Ohshima, T.] Japan Atom Energy Agcy, Takasaki, Gumma 3701292, Japan.
[Sharps, P. R.; Fatemi, N. S.] Emcore Photovolta, Albuquerque, NM 87123 USA.
RP Harris, RD (reprint author), CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
EM richard.d.harris@jpl.nasa.gov; imaizumi.mitsuru@jaxa.jp;
robert.walters@nrl.navy.mil; justin.lorentzen@nrl.navy.mil;
scott.mes-senger@nrl.navy.mil; tischler@nrl.navy.mil;
ohshima.takeshi20@jaea.go.jp; sato.shinichiro@jaea.go.jp;
paul_sharps@emcore.com; navid_fatemi@emcore.com
FU Jet Propulsion Laboratory; California Institute of Technology; National
Aeronautics and Space Administration (NASA)
FX This work was supported in part by the Jet Propulsion Laboratory,
California Institute of Technology, under contract with the National
Aeronautics and Space Administration (NASA).
NR 8
TC 6
Z9 6
U1 1
U2 5
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA
SN 0018-9499
J9 IEEE T NUCL SCI
JI IEEE Trans. Nucl. Sci.
PD DEC
PY 2008
VL 55
IS 6
BP 3502
EP 3507
DI 10.1109/TNS.2008.2006971
PG 6
WC Engineering, Electrical & Electronic; Nuclear Science & Technology
SC Engineering; Nuclear Science & Technology
GA 398DS
UT WOS:000262713400097
ER
PT J
AU Burt, EA
Diener, WA
Tjoelker, RL
AF Burt, Eric A.
Diener, William A.
Tjoelker, Robert L.
TI A Compensated Multi-pole Linear Ion Trap Mercury Frequency Standard for
Ultra-Stable Timekeeping
SO IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL
LA English
DT Article
ID SHIFT
AB The multi-pole linear ion trap frequency standard (LITS) being developed at the Jet Propulsion Laboratory (JPL) has demonstrated excellent short- and long-term stability. The technology has now demonstrated long-term field operation providing a new capability for timekeeping standards. Recently implemented enhancements have resulted in a record line Q of 5 x 10(12) for a room temperature microwave atomic transition and a short-term fractional frequency stability of 5 X 10(-14) /T(1/2). A scheme for compensating the second order Doppler shift has led to a reduction of the combined sensitivity to the primary LITS systematic effects below 5 X 10(-17) fractional frequency. Initial comparisons to JPL's cesium fountain clock show a systematic floor of less than 2 x 10(-16). The compensated multi-pole LITS at JPL was operated continuously and unattended for a 9-mo period from October 2006 to July 2007. During that time it was used as the frequency reference for the JPL geodetic receiver known as JPLT, enabling comparisons to any clock used as a reference for an International GNSS Service (IGS) site. Comparisons with the laser-cooled primary frequency standards that reported to the Bureau International des Poids et Mesures (BIPM) over this period show a frequency deviation less than 2.7 x 10(-17)/day. In the capacity of a stand-alone ultra-stable flywheel, such a standard could be invaluable for long-term timekeeping applications in metrology labs while its methodology and robustness make it ideal for space applications as well.
C1 [Burt, Eric A.; Diener, William A.; Tjoelker, Robert L.] CALTECH, Jet Prop Lab, Frequency & Timing Adv Instrument Dev Grp, Pasadena, CA 91125 USA.
RP Burt, EA (reprint author), CALTECH, Jet Prop Lab, Frequency & Timing Adv Instrument Dev Grp, Pasadena, CA 91125 USA.
EM eric.a.burt@jpl.nasa.gov
FU National Aeronautics and Space Administration
FX This research was carried out at the Jet Propulsion Laboratory,
California Institute of Technology, under a contract with the National
Aeronautics and Space Administration.
NR 27
TC 22
Z9 23
U1 1
U2 12
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA
SN 0885-3010
J9 IEEE T ULTRASON FERR
JI IEEE Trans. Ultrason. Ferroelectr. Freq. Control
PD DEC
PY 2008
VL 55
IS 12
BP 2586
EP 2595
DI 10.1109/TUFFC.2008.975
PG 10
WC Acoustics; Engineering, Electrical & Electronic
SC Acoustics; Engineering
GA 391GM
UT WOS:000262221800007
PM 19126484
ER
PT J
AU Giannakopoulou, D
Pasareanu, CS
Blundell, C
AF Giannakopoulou, D.
Pasareanu, C. S.
Blundell, C.
TI Assume-guarantee testing for software components
SO IET SOFTWARE
LA English
DT Article; Proceedings Paper
CT 6th Workshop on Specification and Verification of Component-Based
Systems (SAVCBS 07)
CY SEP 03-04, 2007
CL Cavtat, CROATIA
AB Integration issues of component-based systems tend to be targeted at the later phases of the software development, mostly after components have been assembled to form an executable system. However, errors discovered at these phases are typically hard to localise and expensive to. x. To address this problem, the authors introduce assume-guarantee testing, a technique that establishes key properties of a component-based system before component assembly, when the cost of. xing errors is smaller. Assume-guarantee testing is based on the ( automated) decomposition of system-level requirements into local component requirements at design time. The local requirements are in the form of assumptions and guarantees that each component makes on, or provides to the system, respectively. Checking requirements is performed during testing of individual components (i.e. unit testing) and it may uncover system-level violations prior to system testing. Furthermore, assume-guarantee testing may detect such violations with a higher probability than traditional testing. The authors also discuss an alternative technique, namely predictive testing, that uses the local component assumptions and guarantees to test assembled systems: given a non-violating system run, this technique can predict violations by alternative system runs without constructing those runs.
The authors demonstrate the proposed approach and its benefits by means of two NASA case studies: a safety-critical protocol for autonomous rendez-vous and docking and the executive subsystem of the planetary rover controller K9.
C1 [Giannakopoulou, D.; Pasareanu, C. S.] NASA, Ames Res Ctr, CMU, Moffett Field, CA 94035 USA.
[Blundell, C.] Univ Penn, Dept Comp & Inf Sci, Philadelphia, PA 19104 USA.
RP Giannakopoulou, D (reprint author), NASA, Ames Res Ctr, CMU, N269-230, Moffett Field, CA 94035 USA.
EM dimitra.giannakopoulou@nasa.gov
NR 31
TC 3
Z9 3
U1 0
U2 3
PU INST ENGINEERING TECHNOLOGY-IET
PI HERTFORD
PA MICHAEL FARADAY HOUSE SIX HILLS WAY STEVENAGE, HERTFORD SG1 2AY, ENGLAND
SN 1751-8806
EI 1751-8814
J9 IET SOFTW
JI IET Softw.
PD DEC
PY 2008
VL 2
IS 6
BP 547
EP 562
DI 10.1049/iet-sen:20080012
PG 16
WC Computer Science, Software Engineering
SC Computer Science
GA 396TH
UT WOS:000262613500006
ER
PT J
AU Lerdthusnee, K
Nigro, J
Monkanna, T
Leepitakrat, W
Leepitakrat, S
Insuan, S
Charoensongsermkit, W
Khlaimanee, N
Akkagraisee, W
Chayapum, K
Jones, JW
AF Lerdthusnee, Kriangkrai
Nigro, Joseph
Monkanna, Taweesak
Leepitakrat, Warisa
Leepitakrat, Surachai
Insuan, Sucheera
Charoensongsermkit, Weerayut
Khlaimanee, Nittaya
Akkagraisee, Wilasinee
Chayapum, Kwanta
Jones, James W.
TI Surveys of rodent-borne disease in Thailand with a focus on scrub typhus
assessment
SO INTEGRATIVE ZOOLOGY
LA English
DT Article
DE GIS model; rodent-borne diseases; scrub typhus; surveillance surveys
AB The epidemiology of many rodent-borne diseases in South-East Asia remains ill-defined. Scrub typhus and leptospirosis are common and medically significant, while other zoonotic diseases, such as spotted fever group Rickettsiae have been identified, but their overall medical significance is unknown. Rodent surveillance was conducted from June 2002 to July 2004 in 18 provinces from Thailand. Traps were set up for one to three nights. Blood and serum samples and animal tissue samples (liver, spleen, kidney and urinary bladder) were collected. Chiggermites, ticks and fleas were removed from captured rodents. A total of 4536 wild-caught rodents from 27 species were captured over two years of animal trapping. Rattus rattus was the dominant species, followed by Rattus exulans and Bandicota indica. Almost 43 000 ectoparasites were removed from the captured animals. Approximately 98% of the ectoparasites were chigger-mites, of which 46% belonged to the genus Leptotrombidium (scrub typhus vector). Other genera included Schoengastia and Blankaartia. Tick and flea specimens together comprised less than 1% of the sample. Among the five species of ticks collected, Haemaphysalis bandicota was the predominant species caught, followed by Ixodes granulatus other Haemaphysalis spp., Rhipicephalus spp. and Dermacentor spp. Only two species of fleas were collected and Xenopsylla cheopis (rat flea) was the predominant species. Using both commercial diagnostic kits and in-house molecular assays, animal tissue samples were examined and screened for zoonotic diseases. Seven zoonotic diseases were detected: scrub typhus, leptospirosis, murine typhus, tick typhus, bartonella, babesiosis and trypanosomiasis. Most samples were positive for scrub typhus. Other zoonotic diseases still under investigation include borrelosis, ehrlichiosis, the plague, and other rickettsial diseases. Using geographic information systems, global positioning systems and remote sensing technology, epidemiological and environmental data were combined to assess the relative risk in different biotopes within highly endemic areas of scrub typhus in Thailand.
C1 [Lerdthusnee, Kriangkrai; Monkanna, Taweesak; Leepitakrat, Warisa; Leepitakrat, Surachai; Insuan, Sucheera; Charoensongsermkit, Weerayut; Khlaimanee, Nittaya; Akkagraisee, Wilasinee; Chayapum, Kwanta; Jones, James W.] Armed Forces Res Inst Med Sci, Dept Entomol, Bangkok 10400, Thailand.
[Nigro, Joseph] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
RP Lerdthusnee, K (reprint author), Armed Forces Res Inst Med Sci, Dept Entomol, 315-6 Rajvithi Rd, Bangkok 10400, Thailand.
EM kriangkrail@afrims.org
FU US. Army Medical and Material Command, Fort Detrick, MD, USA
FX All animal procedures, field activities and experiments were conducted
under the strict guidelines of the Approved Animal Use-Protocols and
were approved by AFRIMS's Institutional Animal Care and Use Committee.
Funding for this project was provided by the Military Infectious
Diseases Research Program of the US. Army Medical and Material Command,
Fort Detrick, MD, USA. The views expressed in this paper are those of
the authors and do not purport to represent the position and/or reflect
the official policy of the Department of the Army, the Department of
Defense or the US Government.
NR 13
TC 12
Z9 14
U1 1
U2 15
PU WILEY-BLACKWELL PUBLISHING, INC
PI MALDEN
PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA
SN 1749-4877
J9 INTEGR ZOOL
JI Integr. Zool.
PD DEC
PY 2008
VL 3
IS 4
BP 267
EP 273
DI 10.1111/j.1749-4877.2008.00100.x
PG 7
WC Zoology
SC Zoology
GA V15GF
UT WOS:000207789800002
PM 21396076
ER
PT J
AU Sakuraba, K
Tsuruda, Y
Hanada, T
Liou, JC
Akahoshi, Y
AF Sakuraba, K.
Tsuruda, Y.
Hanada, T.
Liou, J. -C.
Akahoshi, Y.
TI Investigation and comparison between new satellite impact test results
and NASA standard breakup model
SO INTERNATIONAL JOURNAL OF IMPACT ENGINEERING
LA English
DT Article; Proceedings Paper
CT 10th Hypervelocity Impact Symposium (HVIS 2007)
CY SEP 23-27, 2007
CL Williamsburg, VA
DE Space debris; Modelling; Impact fragmentation
ID LOW-VELOCITY; SPACECRAFT
AB This paper summarizes two new satellite impact tests conducted in order to investigate on the outcome of low- and hypervelocity impacts on two identical target satellites. The first experiment was performed at a low velocity of 1.5 km/s using a 40-g aluminum alloy sphere, whereas the second experiment was performed at a hypervelocity of 4.4 km/s using a 4-g aluminum alloy sphere, by a two-stage light gas gun. To date, approximately 1500 fragments from each impact test have been collected for detailed analysis. Each piece was analyzed based on the method used in the NASA standard breakup model 2000 revision. The detailed analysis will conclude (1) the similarity in mass distribution of fragments between low- and hypervelocity impacts encourages the development of a general-purpose mass-based distribution model applicable for a wide impact velocity range, and (2) the difference in area-to-mass ratio distribution between the impact experiments and the NASA standard breakup model suggests to describe the area-to-mass ratio by a bi-normal distribution. (C) 2008 Published by Elsevier Ltd.
C1 [Sakuraba, K.; Tsuruda, Y.; Hanada, T.] Kyushu Univ, Nishi Ku, Fukuoka 8190395, Japan.
[Liou, J. -C.] NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA.
[Akahoshi, Y.] Kyushu Inst Technol, Tobata Ku, Kitakyushu, Fukuoka 8048550, Japan.
RP Hanada, T (reprint author), Kyushu Univ, Nishi Ku, 744 Motooka, Fukuoka 8190395, Japan.
EM toshi@aero.kyushu-u.ac.jp
NR 8
TC 2
Z9 3
U1 2
U2 5
PU PERGAMON-ELSEVIER SCIENCE LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
SN 0734-743X
J9 INT J IMPACT ENG
JI Int. J. Impact Eng.
PD DEC
PY 2008
VL 35
IS 12
BP 1567
EP 1572
DI 10.1016/j.ijimpeng.2008.07.068
PG 6
WC Engineering, Mechanical; Mechanics
SC Engineering; Mechanics
GA 392YQ
UT WOS:000262338500032
ER
PT J
AU Kearsley, AT
Graham, GA
Burchell, MJ
Cole, MJ
Wozniakiewicz, P
Teslich, N
Bringa, E
Horz, F
Blum, J
Poppe, T
AF Kearsley, A. T.
Graham, G. A.
Burchell, M. J.
Cole, M. J.
Wozniakiewicz, P.
Teslich, N.
Bringa, E.
Horz, F.
Blum, J.
Poppe, T.
TI Micro-craters in aluminum foils: Implications for dust particles from
comet Wild 2 on NASA's Stardust spacecraft
SO INTERNATIONAL JOURNAL OF IMPACT ENGINEERING
LA English
DT Article; Proceedings Paper
CT 10th Hypervelocity Impact Symposium (HVIS 2007)
CY SEP 23-27, 2007
CL Williamsburg, VA
DE Stardust; Wild 2; Cometary dust; Hypervelocity impact; Crater morphology
ID IMPACT FEATURES; 81P/WILD-2; MORPHOLOGY; TARGETS; SAMPLES; SIZE
AB Dust impacts on aluminum foils during encounter of comet 81 P/Wild 2 by the Stardust spacecraft in January 2004 have been simulated using spherical projectiles of monodispersive polymer, glass, and metals, and polydispersive mineral powders of diverse grain shapes. The encounter speed of the cometary particles was a constant and modest 6.1 km s(-1), well within the capabilities of light gas guns. permitting high fidelity experiments to infer dust size, density, and mass from quantitative dimensional analysis of both natural and experimental impact features. Specific interest focused on exceptionally small impactors, all <100 mu m and some as small as 1.5 mu m. To simulate the compound shape of many Stardust craters required novel, artificial aggregate projectiles of heterogeneous mass distribution. We demonstrate that the dimensional scaling obtained previously for millimeter sized impactors extends to particles as small as 10 mu m at 6.1 km s(-1), all yielding a constant relationship for spherical soda lime glass projectiles of diameter (Dp) to crater diameter (Dc) in All 100 of Dc = 4.6 Dp; however, this ratio seems to decrease for projectiles << 10 mu m. The overwhelming majority of the Stardust craters are <20 mu m in diameter, and substantial challenges remain in quantifying the exact size-frequency distribution of the Wild 2 comet dust. Nevertheless, the current experiments provide improved insights into some of the particles' physical properties. (C) 2008 Elsevier Ltd. All rights reserved.
C1 [Kearsley, A. T.; Wozniakiewicz, P.] Nat Hist Museum, Dept Mineral, Impact & Astromat Res Ctr, London SW7 5BD, England.
[Graham, G. A.; Teslich, N.; Bringa, E.] Lawrence Livermore Natl Lab, IGPP, Livermore, CA 94551 USA.
[Burchell, M. J.; Cole, M. J.] Univ Kent, Sch Phys Sci, Canterbury CT2 7NH, Kent, England.
[Wozniakiewicz, P.] Univ London Imperial Coll Sci Technol & Med, Dept Earth Sci & Engn, London SW7 2AZ, England.
[Horz, F.] NASA, Lyndon B Johnson Space Ctr, ESCG, LZ Technol Inc,JE 23, Houston, TX 77058 USA.
[Blum, J.; Poppe, T.] Tech Univ Carolo Wilhelmina Braunschweig, Inst Geophys & Extraterrestr Phys, D-38106 Braunschweig, Germany.
RP Kearsley, AT (reprint author), Nat Hist Museum, Dept Mineral, Impact & Astromat Res Ctr, London SW7 5BD, England.
EM antk@nhm.ac.uk
RI Blum, Jurgen/B-5590-2011; Bringa, Eduardo/F-8918-2011;
OI Blum, Jurgen/0000-0003-1531-737X; Burchell, Mark/0000-0002-2680-8943
NR 19
TC 15
Z9 15
U1 0
U2 5
PU PERGAMON-ELSEVIER SCIENCE LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
SN 0734-743X
J9 INT J IMPACT ENG
JI Int. J. Impact Eng.
PD DEC
PY 2008
VL 35
IS 12
BP 1616
EP 1624
DI 10.1016/j.ijimpeng.2008.07.006
PG 9
WC Engineering, Mechanical; Mechanics
SC Engineering; Mechanics
GA 392YQ
UT WOS:000262338500040
ER
PT J
AU Schonberg, WP
Compton, LE
AF Schonberg, W. P.
Compton, L. E.
TI Application of the NASA/JSC Whipple shield ballistic limit equations to
dual-wall targets under hypervelocity impact
SO INTERNATIONAL JOURNAL OF IMPACT ENGINEERING
LA English
DT Article; Proceedings Paper
CT 10th Hypervelocity Impact Symposium (HVIS 2007)
CY SEP 23-27, 2007
CL Williamsburg, VA
DE Ballistic limit equation; Whipple shield; Obliquity; Penetration;
Dual-wall target
AB All Earth-orbiting spacecraft are susceptible to damage that can be caused by high-speed impacts with pieces of man-made debris or naturally-occurring meteoroids, and spacecraft at locations other than near Earth are subject to similar naturally-occurring hazards. Traditional protective shield design consists of a "bumper" that is placed at a relatively small distance away from the main "inner wall" of the spacecraft component, the performance of which is typically characterized by its ballistic limit equation (BLE). This paper addresses the question of how well the NASA/JSC dual-wall BLE performs when it is used to predict inner wall response in applications other than those used for its development. The major conclusions reached as a result of the analyses performed are that (1) to be truly conservative the critical projectile diameter value as calculated by the NASA/JSC dual-wall BLE needs to be multiplied by 0.75 to accommodate results from other test databases, (2) the NASA/JSC dual-wall BLE is not as conservative for impact obliquities exceeding 60 degrees as it is for obliquities of 45 degrees or less, and (3) the NASA/JSC dual-wall BLE is not as conservative for impact tests with MLI between the bumper and inner wall as it is for tests without the MLI. Published by Elsevier Ltd.
C1 [Schonberg, W. P.] Univ Missouri, Rolla, MO 65401 USA.
[Compton, L. E.] CALTECH, Jet Prop Lab, Pasadena, CA USA.
RP Schonberg, WP (reprint author), Univ Missouri, Rolla, MO 65401 USA.
EM wschon@mst.edu
NR 11
TC 2
Z9 3
U1 1
U2 3
PU PERGAMON-ELSEVIER SCIENCE LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
SN 0734-743X
J9 INT J IMPACT ENG
JI Int. J. Impact Eng.
PD DEC
PY 2008
VL 35
IS 12
BP 1792
EP 1798
DI 10.1016/j.ijimpeng.2008.07.054
PG 7
WC Engineering, Mechanical; Mechanics
SC Engineering; Mechanics
GA 392YQ
UT WOS:000262338500066
ER
PT J
AU Williamsen, JE
Schonberg, WP
Evans, H
Evans, S
AF Williamsen, J. E.
Schonberg, W. P.
Evans, H.
Evans, S.
TI A comparison of NASA, DoD, and hydrocode ballistic limit predictions for
spherical and non-spherical shapes versus dual- and single-wall targets,
and their effects on orbital debris penetration risk
SO INTERNATIONAL JOURNAL OF IMPACT ENGINEERING
LA English
DT Article; Proceedings Paper
CT 10th Hypervelocity Impact Symposium (HVIS 2007)
CY SEP 23-27, 2007
CL Williamsburg, VA
DE NASA; DoD; Hydrocode; Ballistic Limit; Non-Spherical; Penetration Risk;
Dual Wall; Single Wall
ID SPACECRAFT SYSTEMS; EQUATIONS; CURVES
AB All earth-orbiting spacecraft are susceptible to impacts by these particles, which can occur at extremely high speeds and can damage flight- and mission-critical systems. The traditional damage mitigating shield design for this threat consists of a "bumper" that is placed several cm away from the main "inner wall" of the spacecraft. Typical orbital debris risk analyses that include ballistic limit equations (BLEB) and curves (BLCs) assume that orbital debris particles are spherical in shape. However, spheres are not a common shape for orbital debris; rather, debris fragments might be better represented by other regular or irregular solids. This paper presents the results of a study comparing BLCs developed by NASA and the DoD for velocities up to 4 km/s considering spheres, cubes, and a "flake" shape that was proposed within NASA's Standard Breakup Model to represent orbital debris. It also compares performance of these shapes using hydrocodes at higher velocities (7-12 km/s), and generates a combined BLC for these shapes for the entire orbital debris velocity regime. In addition to shape, a multi-view method is used to examine the effects of a variety of cube and flake impact orientations on BLC, as well as a "characteristic length" parameter developed by NASA to compare the particle shapes on the basis of their radar cross section. The developed non-spherical BLCs are then evaluated for overall penetration risk considering the orbital debris environment. Their predictions of risk are compared to that predicted using sphere-based BLCs. This methodology is then extended to a single-wall shield design for velocities up to 15 km/sec, and the results of DoD predictions for a sphere and cube are compared with NASA predictions for a sphere having the same characteristic length. The results indicate that we may be over-predicting orbital debris risk for dual-wall shields by a factor of two-and for single walls by a factor of four-by limiting our analyses to spheres instead of using more representative debris shapes, such as cubes and flakes, and its characteristic length as the primary particle parameter. (C) 2008 Published by Elsevier Ltd.
C1 [Williamsen, J. E.] Inst Def Anal, Alexandria, VA 22311 USA.
[Schonberg, W. P.] Univ Missouri, Dept Civil Engn, Rolla, MO 65401 USA.
[Evans, H.] Univ Denver, Res Inst, Denver, CO 80208 USA.
[Evans, S.] NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA.
RP Williamsen, JE (reprint author), Inst Def Anal, Alexandria, VA 22311 USA.
EM jwilliam@ida.org
NR 14
TC 3
Z9 4
U1 0
U2 4
PU PERGAMON-ELSEVIER SCIENCE LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
SN 0734-743X
J9 INT J IMPACT ENG
JI Int. J. Impact Eng.
PD DEC
PY 2008
VL 35
IS 12
BP 1870
EP 1877
DI 10.1016/j.ijimpeng.2008.07.076
PG 8
WC Engineering, Mechanical; Mechanics
SC Engineering; Mechanics
GA 392YQ
UT WOS:000262338500076
ER
PT J
AU Mukherjee, RM
Crozier, PS
Plimpton, SJ
Anderson, KS
AF Mukherjee, Rudranarayan M.
Crozier, Paul S.
Plimpton, Steven J.
Anderson, Kurt S.
TI Substructured molecular dynamics using multibody dynamics algorithms
SO INTERNATIONAL JOURNAL OF NON-LINEAR MECHANICS
LA English
DT Article
DE Coarse-grained molecular dynamics; Multibody dynamics algorithms;
Open-source software
ID ORDER-N-FORMULATION; NORMAL-MODE ANALYSIS; TIME-STEP METHODS;
CONFORMATIONAL-CHANGE; MOTION SIMULATION; DOMAIN MOTIONS; EWALD SUMS;
SYSTEMS; METHODOLOGY; INTEGRATION
AB This paper reports a new research effort aimed at using efficient multibody dynamics methods to simulate coarse-grained molecular systems. Various molecular systems are studied and the results of nanosecond-long simulations are analyzed to validate the method. The systems studied include bulk water, alkane chains, alanine dipeptide and carboxyl terminal fragments of calmodulin, ribosomal L7/L12 and rhodopsin proteins. The stability and validity of the simulations are studied through conservation of energy, thermodynamics properties and conformational analysis. In these simulations, a speed up of an order of magnitude is realized for conservative error bounds with a fixed timestep integration scheme. A discussion is presented on the open-source software developed to facilitate future research using multibody dynamics with molecular dynamics. Published by Elsevier Ltd.
C1 [Mukherjee, Rudranarayan M.; Anderson, Kurt S.] Rensselaer Polytech Inst, Troy, NY 12180 USA.
[Mukherjee, Rudranarayan M.; Crozier, Paul S.; Plimpton, Steven J.; Anderson, Kurt S.] Sandia Natl Labs, Albuquerque, NM 87185 USA.
RP Mukherjee, RM (reprint author), NASA Jet Prop Lab, Pasadena, CA USA.
EM Rudranarayan.M.Mukherjee@jpl.nasa.gov; pscrozi@sandia.gov;
sjplimp@sandia.gov; anderk5@rpi.edu
FU NSF-NIRT [0303902]; Sandia LDRD [67017]; United States Department of
Energy's National Nuclear Security Administration [DE-AC04-94AL85000]
FX This work was supported in part by NSF-NIRT Grant 0303902 and by Sandia
LDRD 67017. Sandia is a multiprogram laboratory operated by Sandia
Corporation, a Lockheed Martin Company, for the United States Department
of Energy's National Nuclear Security Administration under Contract
DE-AC04-94AL85000. The authors thank the funding agencies for their
support.
NR 60
TC 19
Z9 19
U1 1
U2 8
PU PERGAMON-ELSEVIER SCIENCE LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
SN 0020-7462
J9 INT J NONLIN MECH
JI Int. J. Non-Linear Mech.
PD DEC
PY 2008
VL 43
IS 10
BP 1040
EP 1055
DI 10.1016/j.ijnonlinmec.2008.04.003
PG 16
WC Mechanics
SC Mechanics
GA 389FS
UT WOS:000262077300004
ER
PT J
AU Lin, X
Hou, AY
AF Lin, Xin
Hou, Arthur Y.
TI Evaluation of Coincident Passive Microwave Rainfall Estimates Using TRMM
PR and Ground Measurements as References
SO Journal of Applied Meteorology and Climatology
LA English
DT Article
ID MEASURING MISSION TRMM; LATENT HEATING DISTRIBUTIONS; PRECIPITATION
RADAR; SOUNDING UNIT; SATELLITE-OBSERVATIONS; PHYSICAL RETRIEVALS;
PROFILING ALGORITHM; CLOUD; SENSOR; SCATTERING
AB This study compares instantaneous rainfall estimates provided by the current generation of retrieval algorithms for passive microwave sensors using retrievals from the Tropical Rainfall Measuring Mission (TRMM) precipitation radar (PR) and merged surface radar and gauge measurements over the continental United States as references. The goal is to quantitatively assess surface rain retrievals from cross-track scanning microwave humidity sounders relative to those from conically scanning microwave imagers. The passive microwave sensors included in the study are three operational sounders-the Advanced Microwave Sounding Unit-B (AMSU-B) instruments on the NOAA-15, -16, and -17 satellites-and five imagers: the TRMM Microwave Imager (TMI), the Advanced Microwave Scanning Radiometer for the Earth Observing System (AMSR-E) instrument on the Aqua satellite, and the Special Sensor Microwave Imager (SSM/I) instruments on the Defense Meteorological Satellite Program (DMSP) F-13, -14, and -15 satellites. The comparisons with PR data are based on "coincident" observations, defined as instantaneous retrievals (spatially averaged to 0.25 degrees latitude and 0.25 degrees longitude) within a 10-min interval collected over a 20-month period from January 2005 to August 2006. Statistics of departures of these coincident retrievals from reference measurements as given by the TRMM PR or ground radar and gauges are computed as a function of rain intensity over land and oceans. Results show that over land AMSU-B sounder rain retrievals are comparable in quality to those from conically scanning radiometers for instantaneous rain rates between 1.0 and 10.0 mm h(-1). This result holds true for comparisons using either TRMM PR estimates over tropical land areas or merged ground radar/gauge measurements over the continental United States as the reference. Over tropical oceans, the standard deviation errors are comparable between imager and sounder retrievals for rain intensities above 5 mm h(-1), below which the imagers are noticeably better than the sounders; systematic biases are small for both imagers and sounders. The results of this study suggest that in planning future satellite missions for global precipitation measurement, cross-track scanning microwave humidity sounders on operational satellites may be used to augment conically scanning microwave radiometers to provide improved temporal sampling over land without degradation in the quality of precipitation estimates.
C1 [Lin, Xin; Hou, Arthur Y.] NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Greenbelt, MD 20771 USA.
RP Lin, X (reprint author), NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Code 6101, Greenbelt, MD 20771 USA.
EM xin.lin-1@nasa.gov
RI Hou, Arthur/D-8578-2012
FU GPM Project at the NASA Goddard Space Flight Center in Greenbelt, MD
FX The TRMM PR and TMI pixel data, as well as the gridded SSM/I data, are
obtained from the NASA GSFC Distributed Data Archive Center ( DAAC). The
AMSR-E data are from the National Ice and Snow Center DAAC. The authors
extend their appreciation to George Huffman and Eric Nelkin for
providing the gridded AMSU-B rainfall data, and also to Thomas Bell and
David Wolff for providing estimates of sampling errors associated with
mismatched observation times. Special thanks are given to two anonymous
reviewers for critical and constructive comments that greatly improved
the paper. This research is supported by the GPM Project at the NASA
Goddard Space Flight Center in Greenbelt, MD.
NR 58
TC 29
Z9 29
U1 0
U2 3
PU AMER METEOROLOGICAL SOC
PI BOSTON
PA 45 BEACON ST, BOSTON, MA 02108-3693 USA
SN 1558-8424
J9 J APPL METEOROL CLIM
JI J. Appl. Meteorol. Climatol.
PD DEC
PY 2008
VL 47
IS 12
BP 3170
EP 3187
DI 10.1175/2008JAMC1893.1
PG 18
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 395BF
UT WOS:000262496400010
ER
PT J
AU Smith, GL
Mlynczak, PE
Rutan, DA
Wong, T
AF Smith, G. Louis
Mlynczak, Pamela E.
Rutan, David A.
Wong, Takmeng
TI Comparison of the Diurnal Cycle of Outgoing Longwave Radiation from a
Climate Model with Results from ERBE
SO Journal of Applied Meteorology and Climatology
LA English
DT Article
ID BUDGET EXPERIMENT; CLOUD; SATELLITE; PRECIPITATION; SIMULATION; TROPICS
AB The diurnal cycle of outgoing longwave radiation (OLR) computed by a climate model provides a powerful test of the numerical description of various physical processes. Diurnal cycles of OLR computed by version 3 of the Hadley Centre Atmospheric Model (HadAM3) are compared with those observed by the Earth Radiation Budget Satellite (ERBS) for the boreal summer season (June-August). The ERBS observations cover the domain from 55 degrees S to 55 degrees N. To compare the observed and modeled diurnal cycles, the principal component (PC) analysis method is used over this domain. The analysis is performed separately for the land and ocean regions. For land over this domain, the diurnal cycle computed by the model has a root-mean-square (RMS) of 11.4 W m(-2), as compared with 13.3 W m(-2) for ERBS. PC-1 for ERBS observations and for the model are similar, but the ERBS result has a peak near 1230 LST and decreases very slightly during night, whereas the peak of the model result is an hour later and at night the OLR decreases by 7 W m(-2) between 2000 and 0600 LST. Some of the difference between the ERBS and model results is due to the computation of convection too early in the afternoon by the model. PC-2 describes effects of morning/afternoon cloudiness on OLR, depending on the sign. Over ocean in the ERBS domain, the model RMS of the OLR diurnal cycle is 2.8 W m(-2), as compared with 5.9 W m(-2) for ERBS. Also, for the model, PC-1 accounts for 66% of the variance, while for ERBS, PC-1 accounts for only 16% of the variance. Thus, over ocean, the ERBS results show a greater variety of OLR diurnal cycles than the model does.
C1 [Smith, G. Louis; Wong, Takmeng] NASA, Langley Res Ctr, Hampton, VA 23681 USA.
[Smith, G. Louis] Natl Inst Aerosp, Hampton, VA USA.
[Mlynczak, Pamela E.; Rutan, David A.] Sci Syst & Appl Inc, Hampton, VA USA.
RP Smith, GL (reprint author), NASA, Langley Res Ctr, Mail Stop 420, Hampton, VA 23681 USA.
EM george.l.smith@nasa.gov
FU Earth Sciences Enterprise of NASA
FX The authors were supported in this work by the Earth Sciences Enterprise
of NASA by contract with the Langley Research Center (LaRC) of NASA.
ERBE data for the computation of the diurnal cycle of outgoing longwave
radiation were supplied by the Atmospheric Sciences Data Center of LaRC.
We are indebted to Prof. A. J. Slingo of Reading University for
providing the HadAM3 output for outgoing longwave radiation and for
invaluable discussions. We also thank the reviewers for the insight of
their comments, which improved the paper considerably.
NR 30
TC 5
Z9 6
U1 0
U2 3
PU AMER METEOROLOGICAL SOC
PI BOSTON
PA 45 BEACON ST, BOSTON, MA 02108-3693 USA
SN 1558-8424
J9 J APPL METEOROL CLIM
JI J. Appl. Meteorol. Climatol.
PD DEC
PY 2008
VL 47
IS 12
BP 3188
EP 3201
DI 10.1175/2008JAMC1924.1
PG 14
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 395BF
UT WOS:000262496400011
ER
PT J
AU Suzuki, M
Kumagai, K
Sekiguchi, T
Cassell, AM
Saito, T
Yang, CY
AF Suzuki, Makoto
Kumagai, Kazuhiro
Sekiguchi, Takashi
Cassell, Alan M.
Saito, Tsutomu
Yang, Cary Y.
TI Secondary electron emission from freely supported nanowires
SO JOURNAL OF APPLIED PHYSICS
LA English
DT Article
ID CARBON NANOFIBERS; INSULATING LAYERS; SILICON; BOMBARDMENT; MICROSCOPY;
SPECIMENS; GROWTH; FILMS
AB We present secondary electron (SE) emission results from freely supported carbon/silicon nitride (Si(3)N(4)) hybrid nanowires using scanning electron microscopy. We found that, contrary to bulk materials, the SE emission from insulating or electrically isolated metallic nanowires is strongly suppressed by the penetrating beam. A mechanism of the SE suppression by the positive specimen charging is proposed, which is based on a total emission yield calculation using the Monte Carlo technique. This finding provides an important basis for studying low-energy electron emission from nanostructures under a penetrating electron beam. (C) 2008 American Institute of Physics. [DOI: 10.1063/1.3032910]
C1 [Suzuki, Makoto; Kumagai, Kazuhiro; Sekiguchi, Takashi] Univ Tsukuba, Grad Sch Pure & Appl Sci, Tsukuba, Ibaraki 3058577, Japan.
[Suzuki, Makoto; Kumagai, Kazuhiro; Sekiguchi, Takashi] Natl Inst Mat Sci, Ibaraki 3050044, Japan.
[Cassell, Alan M.] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
[Saito, Tsutomu; Yang, Cary Y.] Santa Clara Univ, Ctr Nanostruct, Santa Clara, CA 95053 USA.
RP Suzuki, M (reprint author), Univ Tsukuba, Grad Sch Pure & Appl Sci, Tsukuba, Ibaraki 3058577, Japan.
EM suzuki-makoto@naka.hiatchi-hitec.com
RI takashi, Sekiguchi/D-2603-2010
NR 38
TC 12
Z9 12
U1 1
U2 4
PU AMER INST PHYSICS
PI MELVILLE
PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1,
MELVILLE, NY 11747-4501 USA
SN 0021-8979
J9 J APPL PHYS
JI J. Appl. Phys.
PD DEC 1
PY 2008
VL 104
IS 11
AR 114306
DI 10.1063/1.3032910
PG 6
WC Physics, Applied
SC Physics
GA 393HI
UT WOS:000262364000132
ER
PT J
AU Lyu, CH
Barnes, WL
AF Lyu, Cheng-Hsuan
Barnes, William L.
TI Ten Years of TRMM/VIRS On-Orbit Calibrations and Multiyear Comparisons
of VIRS and MODIS
SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY
LA English
DT Article
ID RAINFALL MEASURING MISSION; INFRARED SCANNER; TRMM
AB After 10 years of successful operation of the Tropical Rainfall Measuring Mission ( TRMM)/Visible Infrared Scanner ( VIRS), based on sensor performance, the authors have reexamined the calibration algorithms and identified several ways to improve the current VIRS level-1B radiometric calibration software. This study examines the trends in VIRS on-orbit calibration results by using lunar measurements to enable separation of the solar diffuser degradation from that of the VIRS Earth-viewing sensor and by comparing the radiometric data with two nearly identical Moderate Resolution Imaging Spectroradiometer ( MODIS) instruments on board the NASA Earth Observing System ( EOS) Terra and Aqua satellites. For the VIRS, with spectral bands quite similar to several of the MODIS bands, the integrated lunar reflectance data were measured, from January 1998 to March 2007, at phase angles ranging from 0.94 degrees to 121.8 degrees. The authors present trending of the lunar data over periods of 4 yr ( Aqua/MODIS), 6 yr ( Terra/MODIS), and 10 yr ( TRMM/VIRS) and use these observations to examine instrument radiometric stability. The VIRS-measured lunar irradiances are compared with the MODIS-measured lunar irradiances at phase angles around 54 degrees-56 degrees. With the upcoming modified VIRS level-1B version 7 calibration algorithm, the VIRS, along with MODIS, should provide better references for intercalibrating multiple Earth-observing sensors.
C1 [Lyu, Cheng-Hsuan] Sci Syst & Applicat Inc, Lanham, MD USA.
[Barnes, William L.] Univ Maryland Baltimore Cty, Baltimore, MD 21228 USA.
RP Lyu, CH (reprint author), NASA, Goddard Space Flight Ctr, Code 614-4, Greenbelt, MD 20771 USA.
EM lyu@neptune.gsfc.nasa.gov
NR 12
TC 2
Z9 2
U1 0
U2 1
PU AMER METEOROLOGICAL SOC
PI BOSTON
PA 45 BEACON ST, BOSTON, MA 02108-3693 USA
SN 0739-0572
J9 J ATMOS OCEAN TECH
JI J. Atmos. Ocean. Technol.
PD DEC
PY 2008
VL 25
IS 12
BP 2259
EP 2270
DI 10.1175/2008JTECHA1110.1
PG 12
WC Engineering, Ocean; Meteorology & Atmospheric Sciences
SC Engineering; Meteorology & Atmospheric Sciences
GA 387ZU
UT WOS:000261990900009
ER
PT J
AU Wu, Q
McEwen, D
Guo, W
Nidejewski, RJ
Roble, RG
Won, YI
AF Wu, Q.
McEwen, D.
Guo, W.
Nidejewski, R. J.
Roble, R. G.
Won, Y. -I.
TI Long-term thermospheric neutral wind observations over the northern
polar cap
SO JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS
LA English
DT Article
DE Thermospheric dynamics; Polar cap; Fabry-Perot interferometer; Solar
effect
ID INTERPLANETARY MAGNETIC-FIELD; GROUND-BASED OBSERVATIONS; HIGH-LATITUDE;
SOLAR-CYCLE; SOUTH-POLE; CIRCULATION; ANTARCTICA; ION; DYNAMICS; MOTIONS
AB We study the solar dependence of the thermospheric dynamics based on more than 20 years Fabry-Perot interferometer 0 6300 angstrom emission observation of polar cap thermospheric wind from three stations: Thule (76.53 degrees N, 68.73 degrees W, MLAT 86N), Eureka (80.06 degrees N, 86.4 degrees W, MLAT 89N), and Resolute (74.72 degrees N, 94.98 degrees W, MLAT 84N) in combination with the National Center for Atmospheric Research Thermosphere Ionosphere Electrodynamics General Circulation Model (NCAR-TIEGCM). All three stations showed a dominant diurnal oscillation in both the meridional and zonal components, which is a manifestation of anti-sunward thermospheric wind in the polar cap. The three-station observations and the TIEGCM simulation exhibit varying degree of correlations between the anti-sunward thermospheric wind and solar F10.7 index. The diurnal oscillation is stronger at Eureka (similar to 150 m/s) than that at Resolute (similar to 100 m/s) according to both observations and TIEGCM simulation. The semidiurnal oscillation is stronger at Resolute (similar to 20 m/s) than that at Eureka based (similar to 10 m/s) on data and model results. These results are consistent with a two-cell convection pattern in the polar cap thermospheric winds. The Thule results are less consistent between the model and observations. The simulated meridional wind diurnal and semidiurnal oscillations are stronger than those observed. (C) 2008 Elsevier Ltd. All rights reserved.
C1 [Wu, Q.; Roble, R. G.] Natl Ctr Atmospher Res, High Altitude Observ, Boulder, CO 80307 USA.
[McEwen, D.; Guo, W.] Univ Saskatchewan, Dept Phys & Engn Phys, Saskatoon, SK S7N 5E2, Canada.
[Nidejewski, R. J.] Univ Michigan, Space Phys Res Lab, Ann Arbor, MI 48109 USA.
[Won, Y. -I.] NASA, Goddard Space Flight Ctr, RSIS, Goddard Earth Sci DISC, Greenbelt, MD 20771 USA.
RP Wu, Q (reprint author), Natl Ctr Atmospher Res, High Altitude Observ, POB 3000, Boulder, CO 80307 USA.
EM qwu@ucar.edu
NR 24
TC 8
Z9 8
U1 0
U2 1
PU PERGAMON-ELSEVIER SCIENCE LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
SN 1364-6826
J9 J ATMOS SOL-TERR PHY
JI J. Atmos. Sol.-Terr. Phys.
PD DEC
PY 2008
VL 70
IS 16
BP 2014
EP 2030
DI 10.1016/j.jastp.2008.09.004
PG 17
WC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences
SC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences
GA 385KH
UT WOS:000261812600004
ER
PT J
AU Gopalswamy, N
AF Gopalswamy, N.
TI Solar connections of geoeffective magnetic structures
SO JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS
LA English
DT Article; Proceedings Paper
CT 4th Annual Meeting of the Asia-Oceania-Geosciences-Society
CY JUL 30-AUG 04, 2007
CL Bangkok, THAILAND
SP Asia Oceania Geosci Soc
DE Coronal mass ejections; Magnetic clouds; Interplanetary CMEs;
Geomagnetic storms; Solar sources; Geoeffectiveness
ID CORONAL MASS EJECTIONS; COROTATING INTERACTION REGIONS; HIGH-SPEED
STREAMS; GEOMAGNETIC STORMS; INTERPLANETARY SHOCKS; 1-AU ARRIVAL; WIND
SPEED; CLOUDS; FLUX; SOLAR-CYCLE-23
AB Coronal mass ejections (CMEs) and high-speed solar wind streams (HSS) are two solar phenomena that produce large-scale structures in the interplanetary (IP) medium. CMEs evolve into interplanetary CMEs (ICMEs) and the HSS result in corotating interaction regions (CIRs) when they interact with preceding slow solar wind. This paper summarizes the properties of these structures and describes their geoeffectiveness. The primary focus is on the intense storms of solar cycle 23 because this is the first solar cycle during which simultaneous, extensive, and uniform data on solar, IP, and geospace phenomena exist. After presenting illustrative examples of coronal holes and CMEs, I discuss the internal structure of ICMEs, in particular the magnetic clouds (MCs). I then discuss how the magnetic field and speed correlate in the sheath and cloud portions of ICMEs. CME speed measured near the Sun also has significant correlations with the speed and magnetic field strengths measured at 1 AU. The dependence of storm intensity on MC, sheath, and CME properties is discussed pointing to the close connection between solar and IP phenomena. I compare the delay time between MC arrival at I AU and the peak time of storms for the cloud and sheath portions and show that the internal structure of MCs leads to the variations in the observed delay times. Finally, we examine the variation of solar-source latitudes of IP structures as a function of the solar cycle and find that they have to be very close to the disk center. Published by Elsevier Ltd.
C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
RP Gopalswamy, N (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
EM nat.gopalswamy@nasa.gov
RI Gopalswamy, Nat/D-3659-2012
NR 89
TC 28
Z9 29
U1 0
U2 4
PU PERGAMON-ELSEVIER SCIENCE LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
SN 1364-6826
EI 1879-1824
J9 J ATMOS SOL-TERR PHY
JI J. Atmos. Sol.-Terr. Phys.
PD DEC
PY 2008
VL 70
IS 17
SI SI
BP 2078
EP 2100
DI 10.1016/j.jastp.2008.06.010
PG 23
WC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences
SC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences
GA 386TU
UT WOS:000261906300002
ER
PT J
AU Rumaikin, A
Cadavid, AC
Lawrence, J
AF Rumaikin, Alexander
Cadavid, Ana Cristina
Lawrence, John
TI Quasi-periodic patterns coupling the Sun, solar wind and the Earth
SO JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS
LA English
DT Article; Proceedings Paper
CT 4th Annual Meeting of the Asia-Oceania-Geosciences-Society
CY JUL 30-AUG 04, 2007
CL Bangkok, THAILAND
SP Asia Oceania Geosci Soc
DE Solar interior; Solar electric and magnetic fields; Interplanetary
magnetic fields
ID INDEPENDENT COMPONENT ANALYSIS; MAGNETIC-FIELD; WAVELET ANALYSIS;
CONVECTION ZONE; FLUCTUATIONS; LONGITUDES; SEPARATION; SIGNATURES;
1.3-YEAR; ROTATION
AB The spectrum of velocity and magnetic fields in the solar wind is self-similar (power-law type) in the frequency range greater than > 1/day indicating well-mixed turbulence. But it loses self-similarity for lower frequencies indicating the presence of large-scale patterns. which are intermittently generated inside the Sun and propagate from the Sun to the Earth.
Here we discuss the spatia-temporal characteristics and origin of the 1.3-year quasi-periodic pattern found inside the Sun by helioseismic methods and detected in the solar wind. To identify and characterize this pattern on the Sun we use time series of solar magnetic Carrington maps generated at the Wilcox Solar Observatory and independent component data analysis. This analysis shows the latitudinal distribution of the pattern, its variable frequency and intermittent appearance. (C) 2008 Elsevier Ltd. All rights reserved.
C1 [Rumaikin, Alexander] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[Cadavid, Ana Cristina; Lawrence, John] Calif State Univ Northridge, Dept Phys & Astron, Northridge, CA 91300 USA.
RP Rumaikin, A (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM Alexander.Ruzmaikin@jpl.nasa.gov
NR 30
TC 8
Z9 8
U1 0
U2 0
PU PERGAMON-ELSEVIER SCIENCE LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
SN 1364-6826
EI 1879-1824
J9 J ATMOS SOL-TERR PHY
JI J. Atmos. Sol.-Terr. Phys.
PD DEC
PY 2008
VL 70
IS 17
SI SI
BP 2112
EP 2117
DI 10.1016/j.jastp.2008.09.013
PG 6
WC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences
SC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences
GA 386TU
UT WOS:000261906300004
ER
PT J
AU Ferguson, FT
Nuth, JA
AF Ferguson, Frank T.
Nuth, Joseph A., III
TI Vapor Pressure of Silicon Monoxide
SO JOURNAL OF CHEMICAL AND ENGINEERING DATA
LA English
DT Article
ID TRANSMISSION PROBABILITIES; REFRACTORY COMPOUNDS; PHASE NUCLEATION;
SOLID SILICON; KNUDSEN CELL; 1973 K; SIO; CONDENSATION; VAPORIZATION;
IRON
AB Silicon monoxide is a material that is used extensively in the glass and metallurgical industries. In addition, silicon monoxide is also particularly important to the field of astrophysics where it is theorized to play a vital role in the production of metal silicate dust grains in the condensing outflows of dying stars. In this work, the evaporation coefficients and vapor pressure of commercially available amorphous silicon monoxide were measured over the temperature range (1301 to 1519) K using a Knudsen effusion cell and a commercial, thermogravimetric balance. A second- and third-law analysis of the vapor pressure data yielded (351 +/- 11) and (359.1 +/- 2.0) kJ.mol(-1) for the enthalpy of the vaporization reaction at 298.15 K, respectively. It is also shown that a thermodynamic assessment of silicon monoxide vapor pressure that has been used in the modeling of astrophysical condensation at 1000 K and below greatly overpredicts silicon monoxide vapor pressure.
C1 [Ferguson, Frank T.] Catholic Univ Amer, Dept Chem, Washington, DC 20064 USA.
[Nuth, Joseph A., III] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
RP Ferguson, FT (reprint author), Catholic Univ Amer, Dept Chem, Washington, DC 20064 USA.
EM frank.ferguson@nasa.gov
RI Ferguson, Frank/C-9493-2012; Nuth, Joseph/E-7085-2012
NR 35
TC 29
Z9 29
U1 2
U2 20
PU AMER CHEMICAL SOC
PI WASHINGTON
PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA
SN 0021-9568
J9 J CHEM ENG DATA
JI J. Chem. Eng. Data
PD DEC
PY 2008
VL 53
IS 12
BP 2824
EP 2832
DI 10.1021/je800560b
PG 9
WC Thermodynamics; Chemistry, Multidisciplinary; Engineering, Chemical
SC Thermodynamics; Chemistry; Engineering
GA 383EV
UT WOS:000261657800020
ER
PT J
AU Eitzen, ZA
Xu, KM
Wong, T
AF Eitzen, Zachary A.
Xu, Kuan-Man
Wong, Takmeng
TI Statistical Analyses of Satellite Cloud Object Data from CERES. Part V:
Relationships between Physical Properties of Marine Boundary Layer
Clouds
SO JOURNAL OF CLIMATE
LA English
DT Article
ID 1998 EL-NINO; TROPICAL WESTERN PACIFIC; SEA-SURFACE TEMPERATURE;
MICROPHYSICAL PROPERTIES; STRATOCUMULUS CLOUDS; AEROSOL RETRIEVALS;
MODEL SIMULATIONS; EFFECTIVE RADIUS; RADIATION; VALIDATION
AB Relationships between physical properties are studied for three types of marine boundary layer cloud objects identified with the Clouds and the Earth's Radiant Energy System (CERES) footprint data from the Tropical Rainfall Measuring Mission satellite between 30 degrees S and 30 degrees N. Each cloud object is a contiguous region of CERES footprints that have cloud-top heights below 3 km, and cloud fractions of 99%-100% (overcast type), 40%-99% (stratocumulus type), or 10%-40% (shallow cumulus type). These cloud fractions represent the fraction of similar to 2 km x 2 km Visible/Infrared Scanner pixels that are cloudy within each similar to 10 km x 10 km footprint. The cloud objects have effective diameters that are greater than 300 km for the overcast and stratocumulus types, and greater than 150 km for the shallow cumulus type. The Spearman rank correlation coefficient is calculated between many microphysical/optical [effective radius (r(e)), cloud optical depth (tau), albedo, liquid water path, and shortwave cloud radiative forcing (SW CRF)] and macrophysical [outgoing longwave radiation (OLR), cloud fraction, cloud-top temperature, longwave cloud radiative forcing (LW CRF), and sea surface temperature (SST)] properties for each of the three cloud object types. When both physical properties are of the same category (microphysical/optical or macrophysical), the magnitude of the correlation tends to be higher than when they are from different categories. The magnitudes of the correlations also change with cloud object type, with the correlations for overcast and stratocumulus cloud objects tending to be higher than those for shallow cumulus cloud objects.
Three pairs of physical properties are studied in detail, using a k-means cluster analysis: r(e) and tau, OLR and SST, and LW CRF and SW CRF. The cluster analysis of r(e) and tau reveals that for each of the cloud types, there is a cluster of cloud objects with negative slopes, a cluster with slopes near zero, and two clusters with positive slopes. The joint OLR and SST probability plots show that the OLR tends to decrease with SST in regions with boundary layer clouds for SSTs above approximately 298 K. When the cloud objects are split into "dry" and "moist" clusters based on the amount of precipitable water above 700 hPa, the associated OLRs increase with SST throughout the SST range for the dry clusters, but the OLRs are roughly constant with SST for the moist cluster. An analysis of the joint PDFs of LW CRF and SW CRF reveals that while the magnitudes of both LW and SW CRFs generally increase with cloud fraction, there is a cluster of overcast cloud objects that has low values of LW and SW CRF. These objects are generally located near the Sahara Desert, and may be contaminated with dust. Many of these overcast objects also appear in the re and tau cluster with negative slopes.
C1 [Eitzen, Zachary A.; Xu, Kuan-Man; Wong, Takmeng] NASA, Langley Res Ctr, Hampton, VA 23681 USA.
[Eitzen, Zachary A.] Sci Syst & Applicat Inc, Hampton, VA USA.
RP Eitzen, ZA (reprint author), NASA, Langley Res Ctr, Mail Stop 420, Hampton, VA 23681 USA.
EM zachary.a.eitzen@nasa.gov
RI Xu, Kuan-Man/B-7557-2013
OI Xu, Kuan-Man/0000-0001-7851-2629
FU NASA EOS interdisciplinary study program; Modeling, Analysis and
Prediction program managed by Drs. Don Anderson and Hal Maring
FX The CERES data were obtained from the Atmospheric Sciences Data Center
at the NASA Langley Data Center. This research has been supported by the
NASA EOS interdisciplinary study program, and the Modeling, Analysis and
Prediction program managed by Drs. Don Anderson and Hal Maring. The
authors thank three anonymous reviewers for their helpful comments. The
authors would like to acknowledge Dr. Bruce Wielicki for his earlier
insightful vision on this project, Mr. Lindsay Parker for producing the
initial cloud object data, and Drs. Tom Charlock, Fu-Lung Chang, Seiji
Kato, Norman Loeb, and Patrick Minnis of the CERES Science team for
helpful discussions.
NR 48
TC 14
Z9 14
U1 0
U2 6
PU AMER METEOROLOGICAL SOC
PI BOSTON
PA 45 BEACON ST, BOSTON, MA 02108-3693 USA
SN 0894-8755
J9 J CLIMATE
JI J. Clim.
PD DEC
PY 2008
VL 21
IS 24
BP 6668
EP 6688
DI 10.1175/2008JCLI2307.1
PG 21
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 392UZ
UT WOS:000262329000013
ER
PT J
AU Kim, SM
Yuen, HB
Hatami, F
Chin, A
Harris, JS
AF Kim, S. M.
Yuen, H. B.
Hatami, F.
Chin, A.
Harris, J. S.
TI Optical Properties of Dilute Nitride InN(As)Sb Quantum Wells and Quantum
Dots Grown by Molecular Beam Epitaxy
SO JOURNAL OF ELECTRONIC MATERIALS
LA English
DT Article
DE Infrared; narrow bandgap; quantum dots; quantum wells; molecular beam
epitaxy
ID PHOTOLUMINESCENCE; GAINNAS; ALLOYS; SHIFT
AB We report the growth and characterization of a new dilute nitride infrared material: InN(As)Sb. InNAsSb single quantum wells (SQWs) and InNSb self-assembled quantum dots (QDs) were grown on both InAs and GaAs substrates by solid-source molecular beam epitaxy. High-quality InNAsSb epilayers were realized by optimizing the nitrogen incorporation growth conditions. Both secondary-ion mass spectroscopy and x-ray diffraction measurements confirmed a nitrogen incorporation of 1%. Temperature- and power-dependent photoluminescence measurements were conducted and revealed a luminescence emission at 4.03 mu m from localized states and similar to 4.3 mu m from the ground-state transition in InNAsSb SQWs. InNSb QDs exhibited a 10 K photoluminescence peak at 3.6 mu m.
C1 [Kim, S. M.; Yuen, H. B.; Hatami, F.; Harris, J. S.] Stanford Univ, Dept Elect Engn, Solid State & Photon Lab, Stanford, CA 94305 USA.
[Kim, S. M.] Univ Alabama, Dept Elect & Comp Engn, Tuscaloosa, AL 35487 USA.
[Chin, A.] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
RP Kim, SM (reprint author), Stanford Univ, Dept Elect Engn, Solid State & Photon Lab, Stanford, CA 94305 USA.
EM seongsin@eng.ua.edu
RI Hatami, Fariba/D-6807-2015
OI Hatami, Fariba/0000-0001-8033-3873
NR 17
TC 3
Z9 3
U1 0
U2 1
PU SPRINGER
PI NEW YORK
PA 233 SPRING ST, NEW YORK, NY 10013 USA
SN 0361-5235
J9 J ELECTRON MATER
JI J. Electron. Mater.
PD DEC
PY 2008
VL 37
IS 12
BP 1774
EP 1779
DI 10.1007/s11664-008-0472-x
PG 6
WC Engineering, Electrical & Electronic; Materials Science,
Multidisciplinary; Physics, Applied
SC Engineering; Materials Science; Physics
GA 365AD
UT WOS:000260377400005
ER
PT J
AU Quesnel, Y
Langlais, B
Sotin, C
Galdeano, A
AF Quesnel, Y.
Langlais, B.
Sotin, C.
Galdeano, A.
TI Modelling and inversion of local magnetic anomalies
SO JOURNAL OF GEOPHYSICS AND ENGINEERING
LA English
DT Article
DE magnetic anomalies; modeling; inversion; crustal magnetized sources;
dipoles; Champtoceaux complex
ID NAPPE ARMORICAN MASSIF; ANALYTIC SIGNAL; HORIZONTAL CYLINDERS;
SHEAR-ZONE; FIELD; COMPUTER; GRAVITY; PROGRAM; FRANCE; DEPTH
AB We present a method-named as MILMA for modelling and inversion of local magnetic anomalies-that combines forward and inverse modelling of aeromagnetic data to characterize both magnetization properties and location of unconstrained local sources. Parameters of simple-shape magnetized bodies ( cylinder, prism or sphere) are first adjusted by trial and error to predict the signal. Their parameters provide a priori information for inversion of the measurements. Here, a generalized nonlinear approach with a least-squares criterion is adopted to seek the best parameters of the sphere ( dipole). This inversion step allows the model to be more objectively adjusted to fit the magnetic signal. The validity of the MILMA method is demonstrated through synthetic and real cases using aeromagnetic measurements. Tests with synthetic data reveal accurate results in terms of depth source, whatever be the number of sources. The MILMA method is then used with real measurements to constrain the properties of the magnetized units of the Champtoceaux complex ( France). The resulting parameters correlate with the crustal structure and properties revealed by other geological and geophysical surveys in the same area. The MILMA method can therefore be used to investigate the properties of poorly constrained lithospheric magnetized sources.
C1 [Quesnel, Y.] GFZ German Res Ctr Geosci, D-14473 Potsdam, Germany.
[Langlais, B.] CNRS, Lab Planetol & Geodynam, UMR 6112, F-44322 Nantes, France.
[Langlais, B.] Univ Nantes, Lab Planetol & Geodynam, F-44322 Nantes, France.
[Sotin, C.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[Galdeano, A.] Inst Phys Globe, CNRS, UMR 7154, F-75252 Paris 05, France.
RP Quesnel, Y (reprint author), GFZ German Res Ctr Geosci, D-14473 Potsdam, Germany.
EM quesnel@gfz-potsdam.de
RI Langlais, Benoit/K-5366-2012
OI Langlais, Benoit/0000-0001-5207-304X
FU INSU/CNES Programme National de Planetologie
FX We thank the two anonymous reviewers for their thoughtful, constructive
comments. The aeromagnetic dataset over Brittany ( France) was kindly
provided by C Truffert and the 'Bureau de Recherche Geologiques et
Minieres'. We also thank V Lesur, M Mandea, M Purucker, E Thebault and C
Gumiaux for fruitful discussions. This study was initially supported by
INSU/CNES Programme National de Planetologie.
NR 66
TC 8
Z9 8
U1 0
U2 8
PU IOP PUBLISHING LTD
PI BRISTOL
PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND
SN 1742-2132
J9 J GEOPHYS ENG
JI J. Geophys. Eng.
PD DEC
PY 2008
VL 5
IS 4
BP 387
EP 400
DI 10.1088/1742-2132/5/4/003
PG 14
WC Geochemistry & Geophysics
SC Geochemistry & Geophysics
GA 383TH
UT WOS:000261695900003
ER
PT J
AU Habib, E
Malakpet, CG
Tokay, A
Kucera, PA
AF Habib, Emad
Malakpet, Chakradhar G.
Tokay, Ali
Kucera, Paul A.
TI Sensitivity of Streamflow Simulations to Temporal Variability and
Estimation of Z-R Relationships
SO JOURNAL OF HYDROLOGIC ENGINEERING
LA English
DT Article
ID DROP SIZE; RADAR OBSERVATIONS; RAINDROP SPECTRA; RAINFALL;
PRECIPITATION; REFLECTIVITY; ACCURACY; UNCERTAINTIES; DISTRIBUTIONS;
PREDICTION
AB This study focuses on the sensitivity of streamflow simulations to temporal variations in radar reflectivity-rainfall (i.e., Z-R) relationships. The physically based continuous-mode distributed hydrologic model-gridded surface subsurface hydrologic analysis-is used to predict runoff during three major rainfall-runoff periods observed in a 35 km(2) experimental watershed in southern Louisiana. Z-R relationships are derived at a series of temporal scales ranging from a climatological scale, where interstorm Z-R variations are ignored, down to a subevent scale, where variations in rainfall type (convective versus stratiform) are taken into account. The analysis is first performed using Z and R data pairs derived directly from disdrometer drop size distribution measurements, and then repeated using WSR-88D radar reflectivity data. The degree of sensitivity in runoff simulations to temporal variations in Z-R relationships depends largely on the method used to derive the parameters of these relationships. Using event-specific Z-R relationships results in accurate hydrographs when the parameters are derived based on bias removal and minimization of random errors of rainfall estimates. Methods based on least-squares fitting require refining the derivation of Z-R parameters down to a subevent scale, which is not practically feasible. A simple and practical method based on selection of a climatologically representative exponent of the Z-R relationships and adjusting the multiplier coefficient through bias removal still results in reasonably accurate runoff simulations, but only when event-specific Z-R relationships are used.
C1 [Habib, Emad; Malakpet, Chakradhar G.] Univ Louisiana Lafayette, Dept Civil Engn, Lafayette, LA 70504 USA.
[Tokay, Ali] Univ Maryland Baltimore Cty, Joint Ctr Earth Syst Technol, Baltimore, MD 21250 USA.
[Tokay, Ali] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
[Kucera, Paul A.] Natl Ctr Atmospher Res, Res Applicat Lab, Boulder, CO 80307 USA.
RP Habib, E (reprint author), Univ Louisiana Lafayette, Dept Civil Engn, POB 42291, Lafayette, LA 70504 USA.
EM habib@louisiana.edu
FU Research Competitiveness Sub-program of the Louisiana Board of Regents;
LaSPACE Research Enhancement Awards [NNG05GH22H]
FX This work was supported by the Research Competitiveness Sub-program of
the Louisiana Board of Regents Support Fund and by the LaSPACE Research
Enhancement Awards program under the agreement NASA/LEQSF
(2005-2010)-LaSPACE and NASA/LaSPACE under Training Grant NNG05GH22H.
The writers would like to thank David Marks of George Mason University
and NASA Goddard Space Flight Center for generating
stratiform/convective classification from radar reflectivity data for
the October 2004 storm, which were used to verify visually based
classifications for the rest of the storms.
NR 32
TC 14
Z9 14
U1 1
U2 1
PU ASCE-AMER SOC CIVIL ENGINEERS
PI RESTON
PA 1801 ALEXANDER BELL DR, RESTON, VA 20191-4400 USA
SN 1084-0699
J9 J HYDROL ENG
JI J. Hydrol. Eng.
PD DEC
PY 2008
VL 13
IS 12
BP 1177
EP 1186
DI 10.1061/(ASCE)1084-0699(2008)13:12(1177)
PG 10
WC Engineering, Civil; Environmental Sciences; Water Resources
SC Engineering; Environmental Sciences & Ecology; Water Resources
GA 372YI
UT WOS:000260937800008
ER
PT J
AU Case, JL
Crosson, WL
Kumar, SV
Lapenta, WM
Peters-Lidard, CD
AF Case, Jonathan L.
Crosson, William L.
Kumar, Sujay V.
Lapenta, William M.
Peters-Lidard, Christa D.
TI Impacts of High-Resolution Land Surface Initialization on Regional
Sensible Weather Forecasts from the WRF Model
SO JOURNAL OF HYDROMETEOROLOGY
LA English
DT Article
ID SCALE ATMOSPHERIC PROCESSES; DATA ASSIMILATION SYSTEM; SOUTHERN
GREAT-PLAINS; PART I; PREDICTION MODELS; BOUNDARY-LAYER; SOIL-MOISTURE;
ETA-MODEL; MESOSCALE; CONVECTION
AB This manuscript presents an assessment of daily regional simulations of the Weather Research and Forecasting (WRF) numerical weather prediction (NWP) model initialized with high-resolution land surface data from the NASA Land Information System ( LIS) software versus a control WRF configuration that uses land surface data from the National Centers for Environmental Prediction (NCEP) Eta Model. The goal of this study is to investigate the potential benefits of using the LIS software to improve land surface initialization for regional NWP. Fifty-eight individual nested simulations were integrated for 24 h for both the control and experimental (LISWRF) configurations during May 2004 over Florida and the surrounding areas: 29 initialized at 0000 UTC and 29 initialized at 1200 UTC. The land surface initial conditions for the LISWRF runs came from an offline integration of the Noah land surface model (LSM) within LIS for two years prior to the beginning of the month-long study on an identical grid domain to the subsequent WRF simulations. Atmospheric variables used to force the offline Noah LSM integration were provided by the North American Land Data Assimilation System and Global Data Assimilation System gridded analyses.
The LISWRF soil states were generally cooler and drier than the NCEP Eta Model soil states during May 2004. Comparisons between the control and LISWRF runs for one event suggested that the LIS land surface initial conditions led to an improvement in the timing and evolution of a sea-breeze circulation over portions of northwestern Florida. Surface verification statistics for the entire month indicated that the LISWRF runs produced a more enhanced and accurate diurnal range in 2-m temperatures compared to the control as a result of the overall drier initial soil states, which resulted from a reduction in the nocturnal warm bias in conjunction with a reduction in the daytime cold bias. Daytime LISWRF 2-m dewpoints were correspondingly drier than the control dewpoints, again a manifestation of the drier initial soil states in LISWRF. The positive results of the LISWRF experiments help to illustrate the importance of initializing regional NWP models with high-quality land surface data generated at the same grid resolution.
C1 [Case, Jonathan L.] NASA, Short Term Predict Res & Transit Ctr, ENSCO Inc, Huntsville, AL USA.
[Crosson, William L.] NASA, George C Marshall Space Flight Ctr, Univ Space Res Assoc, Huntsville, AL 35812 USA.
[Kumar, Sujay V.] Goddard Earth Sci & Technol Ctr, Greenbelt, MD USA.
[Lapenta, William M.] NASA, George C Marshall Space Flight Ctr, Short Term Predict Res & Transit Ctr, Huntsville, AL 35812 USA.
[Peters-Lidard, Christa D.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
RP Case, JL (reprint author), Natl Space Sci & Technol Ctr, 320 Sparkman Dr,Room 3062, Huntsville, AL 35805 USA.
EM jonathan.case-1@nasa.gov
RI Kumar, Sujay/B-8142-2015; Peters-Lidard, Christa/E-1429-2012
OI Peters-Lidard, Christa/0000-0003-1255-2876
NR 47
TC 29
Z9 30
U1 2
U2 14
PU AMER METEOROLOGICAL SOC
PI BOSTON
PA 45 BEACON ST, BOSTON, MA 02108-3693 USA
SN 1525-755X
J9 J HYDROMETEOROL
JI J. Hydrometeorol.
PD DEC
PY 2008
VL 9
IS 6
BP 1249
EP 1266
DI 10.1175/2008JHM990.1
PG 18
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 386DD
UT WOS:000261861600007
ER
PT J
AU Davis, RE
Painter, TH
Cline, D
Armstrong, R
Haran, T
McDonald, K
Forster, R
Elder, K
AF Davis, Robert E.
Painter, Thomas H.
Cline, Don
Armstrong, Richard
Haran, Terry
McDonald, Kyle
Forster, Rick
Elder, Kelly
TI NASA Cold Land Processes Experiment (CLPX 2002/03): Spaceborne Remote
Sensing
SO JOURNAL OF HYDROMETEOROLOGY
LA English
DT Article
ID SNOW WATER EQUIVALENT; THEMATIC MAPPER; GRAIN-SIZE; COVER; RESOLUTION;
RETRIEVAL
AB This paper describes satellite data collected as part of the 2002/03 Cold Land Processes Experiment (CLPX). These data include multispectral and hyperspectral optical imaging, and passive and active microwave observations of the test areas. The CLPX multispectral optical data include the Advanced Very High Resolution Radiometer (AVHRR), the Landsat Thematic Mapper/Enhanced Thematic Mapper Plus (TM/ETM +), the Moderate Resolution Imaging Spectroradiometer ( MODIS), and the Multi-angle Imaging Spectroradiometer (MISR). The spaceborne hyperspectral optical data consist of measurements acquired with the NASA Earth Observing-1 (EO-1) Hyperion imaging spectrometer. The passive microwave data include observations from the Special Sensor Microwave Imager (SSM/I) and the Advanced Microwave Scanning Radiometer (AMSR) for Earth Observing System (EOS; AMSR-E). Observations from the Radarsat synthetic aperture radar and the SeaWinds scatterometer flown on QuikSCAT make up the active microwave data.
C1 [Davis, Robert E.] USACE, Cold Reg Res & Engn Lab, Hanover, NH 03755 USA.
[Painter, Thomas H.; Forster, Rick] Univ Utah, Dept Geog, Salt Lake City, UT USA.
[Cline, Don] Natl Weather Serv, Natl Operat Remote Sensing Hydrol Ctr, Chanhassen, MN USA.
[Armstrong, Richard; Haran, Terry] Univ Colorado, Natl Snow & Ice Data Ctr, Boulder, CO 80309 USA.
[McDonald, Kyle] CALTECH, Jet Prop Lab, Pasadena, CA USA.
[Elder, Kelly] US Forest Serv, Rocky Mt Res Stn, USDA, Ft Collins, CO USA.
RP Davis, RE (reprint author), USACE, Cold Reg Res & Engn Lab, 72 Lyme Rd, Hanover, NH 03755 USA.
EM robert.e.davis@erdc.usace.army.mil
RI Painter, Thomas/B-7806-2016
FU National Aeronautics and Space Administration (NASA) Earth Science
Enterprise; Terrestrial Hydrology Program; Earth Observing System
Program; Airborne Science Program; National Oceanic and Atmospheric
Administration Office of Global Programs; U. S. Army Corps of Engineers
Civil Works Remote Sensing Research Program; the U. S. Army Basic
Research Program; National Space Development Agency of Japan (NASDA);
Japan Science and Technology Corporation; National Assembly for Wales;
Science Research Investment Fund; Cardiff University; Jet Propulsion
Laboratory at the California Institute of Technology
FX This work was funded through the cooperation of many agencies and
organizations including the National Aeronautics and Space
Administration (NASA) Earth Science Enterprise, Terrestrial Hydrology
Program, Earth Observing System Program, and Airborne Science Program;
the National Oceanic and Atmospheric Administration Office of Global
Programs; the U. S. Army Corps of Engineers Civil Works Remote Sensing
Research Program; the U. S. Army Basic Research Program; the National
Space Development Agency of Japan (NASDA); the Japan Science and
Technology Corporation; and the National Assembly for Wales, Science
Research Investment Fund, Cardiff University. A portion of this work was
conducted at the Jet Propulsion Laboratory at the California Institute
of Technology, under contract to NASA. More than 200 people participated
in the planning and execution of CLPX 2002/03. Their efforts are very
much appreciated. We would also like to thank the two anonymous and
thorough reviewers who helped to improve the manuscript.
NR 30
TC 4
Z9 4
U1 0
U2 5
PU AMER METEOROLOGICAL SOC
PI BOSTON
PA 45 BEACON ST, BOSTON, MA 02108-3693 USA
SN 1525-755X
J9 J HYDROMETEOROL
JI J. Hydrometeorol.
PD DEC
PY 2008
VL 9
IS 6
BP 1427
EP 1433
DI 10.1175/2008JHM926.1
PG 7
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 386DD
UT WOS:000261861600019
ER
PT J
AU Hardy, J
Davis, R
Koh, Y
Cline, D
Elder, K
Armstrong, R
Marshall, HP
Painter, T
Saint-Martin, GC
Deroo, R
Sarabandi, K
Graf, T
Koike, T
McDonald, K
AF Hardy, Janet
Davis, Robert
Koh, Yeohoon
Cline, Don
Elder, Kelly
Armstrong, Richard
Marshall, Hans-Peter
Painter, Thomas
Saint-Martin, Gilles Castres
Deroo, Roger
Sarabandi, Kamal
Graf, Tobias
Koike, Toshio
McDonald, Kyle
TI NASA Cold Land Processes Experiment (CLPX 2002/03): Local Scale
Observation Site
SO JOURNAL OF HYDROMETEOROLOGY
LA English
DT Article
AB The local scale observation site (LSOS) is the smallest study site (0.8 ha) of the 2002/03 Cold Land Processes Experiment (CLPX) and is located within the Fraser mesocell study area. It was the most intensively measured site of the CLPX, and measurements here had the greatest temporal component of all CLPX sites. Measurements made at the LSOS were designed to produce a comprehensive assessment of the snow, soil, and vegetation characteristics viewed by the ground-based remote sensing instruments. The objective of the ground-based microwave remote sensing was to collect time series of active and passive microwave spectral signatures over snow, soil, and forest, which is coincident with the intensive physical characterization of these features. Ground-based remote sensing instruments included frequency modulated continuous wave (FMCW) radars operating over multiple microwave bandwidths; the Ground-Based Microwave Radiometer (GBMR-7) operating at channels 18.7, 23.8, 36.5, and 89 GHz; and in 2003, an L-, C-, X- and Ku-band scatterometer radar system. Snow and soil measurements included standard snow physical properties, snow wetness, snow depth transects, and soil moisture. The stem and canopy temperature and xylem sap flux of several trees were monitored continuously. Five micrometeorological towers monitored ambient conditions and provided forcing datasets for 1D snow and soil models. Arrays of pyranometers (0.3-3 mu m) and a scanning thermal radiometer (8-12 mu m) characterized the variability of radiative receipt in the forests. A field spectroradiometer measured the hyperspectral hemispherical-directional reflectance of the snow surface. These measurements, together with the ground-based remote sensing, provide the framework for evaluating and improving microwave radiative transfer models and coupling them to land surface models. The dataset is archived at the National Snow and Ice Data Center (NSIDC) in Boulder, Colorado.
C1 [Hardy, Janet; Davis, Robert; Koh, Yeohoon] US Army Corps Engineers, Engn Res & Dev Ctr, CRREL, Hanover, NH 03755 USA.
[Cline, Don] NOAA, NWS, Natl Operat Hydrol Remote Sensing Ctr, Chanhassen, MN USA.
[Elder, Kelly] US Forest Serv, USDA, Ft Collins, CO USA.
[Armstrong, Richard; Marshall, Hans-Peter] Univ Colorado, Boulder, CO 80309 USA.
[Painter, Thomas] Univ Utah, Salt Lake City, UT USA.
[Saint-Martin, Gilles Castres; Deroo, Roger; Sarabandi, Kamal] Univ Michigan, Ann Arbor, MI 48109 USA.
[Graf, Tobias; Koike, Toshio] Univ Tokyo, Tokyo, Japan.
[McDonald, Kyle] CALTECH, Jet Prop Lab, NASA, Pasadena, CA USA.
RP Hardy, J (reprint author), US Army Corps Engineers, Engn Res & Dev Ctr, CRREL, 72 Lyme Rd, Hanover, NH 03755 USA.
EM janet.p.hardy@usace.army.mil
RI Marshall, Hans-Peter/A-2374-2010; De Roo, Roger/J-2208-2012; Painter,
Thomas/B-7806-2016
OI Marshall, Hans-Peter/0000-0002-4852-5637; De Roo,
Roger/0000-0001-8391-2950;
FU National Aeronautics and Space Administration (NASA); U. S. Army Corps
of Engineers Civil Works Remote Sensing Research Program; U. S. Army
Basic Research Program; Japan Aerospace Exploration Agency (JAXA); Japan
Science and Technology Agency; National Assembly for Wales; Strategic
Research Investment Fund, Cardiff; Jet Propulsion Laboratory at the
California Institute of Technology
FX This work was funded through cooperation of many agencies and
organizations including the National Aeronautics and Space
Administration (NASA), the U. S. Army Corps of Engineers Civil Works
Remote Sensing Research Program, the U. S. Army Basic Research Program,
the Japan Aerospace Exploration Agency (JAXA), the Japan Science and
Technology Agency, and the National Assembly for Wales, Strategic
Research Investment Fund, Cardiff. A portion of this work was conducted
at the Jet Propulsion Laboratory at the California Institute of
Technology, under contract to NASA.
NR 12
TC 6
Z9 8
U1 0
U2 5
PU AMER METEOROLOGICAL SOC
PI BOSTON
PA 45 BEACON ST, BOSTON, MA 02108-3693 USA
SN 1525-755X
J9 J HYDROMETEOROL
JI J. Hydrometeorol.
PD DEC
PY 2008
VL 9
IS 6
BP 1434
EP 1442
DI 10.1175/2008JHM875.1
PG 9
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 386DD
UT WOS:000261861600020
ER
PT J
AU Feng, X
Sahoo, A
Arsenault, K
Houser, P
Luo, Y
Troy, TJ
AF Feng, Xia
Sahoo, Alok
Arsenault, Kristi
Houser, Paul
Luo, Yan
Troy, Tara J.
TI The Impact of Snow Model Complexity at Three CLPX Sites
SO JOURNAL OF HYDROMETEOROLOGY
LA English
DT Article
ID GENERAL-CIRCULATION MODELS; LAND-SURFACE MODEL; BIOSPHERE MODEL; ALPINE
SITE; PILPS 2(D); HYDROLOGY; FOREST; COVER; CLIMATE; SIMULATIONS
AB Many studies have developed snow process understanding by exploring the impact of snow model complexity on simulation performance. This paper revisits this topic using several recently developed land surface models, including the Simplified Simple Biosphere Model (SSiB); Noah; Variable Infiltration Capacity (VIC); Community Land Model, version 3 (CLM3); Snow Thermal Model (SNTHERM); and new field measurements from the Cold Land Processes Field Experiment (CLPX). Offline snow cover simulations using these five snow models with different physical complexity are performed for the Rabbit Ears Buffalo Pass (RB), Fraser Experimental Forest headquarters (FHQ), and Fraser Alpine ( FA) sites between 20 September 2002 and 1 October 2003. These models simulate the snow accumulation and snowpack ablation with varying skill when forced with the same meteorological observations, initial conditions, and similar soil and vegetation parameters.
All five models capture the basic features of snow cover dynamics but show remarkable discrepancy in depicting snow accumulation and ablation, which could result from uncertain model physics and/or biased forcing. The simulated snow depth in SSiB during the snow accumulation period is consistent with the more complicated CLM3 and SNTHERM; however, early runoff is noted, owing to neglected water retention within the snowpack. Noah is consistent with SSiB in simulating snow accumulation and ablation at RB and FA, but at FHQ, Noah underestimates snow depth and snow water equivalent (SWE) as a result of a higher net shortwave radiation at the surface, resulting from the use of a small predefined maximum snow albedo. VIC and SNTHERM are in good agreement with each other, and they realistically reproduce snow density and net radiation. CLM3 is consistent with VIC and SNTHERM during snow accumulation, but it shows early snow disappearance at FHQ and FA. It is also noted that VIC, CLM3, and SNTHERM are unable to capture the observed runoff timing, even though the water storage and refreezing effects are included in their physics.
A set of sensitivity experiments suggest that Noah's snow simulation is improved with a higher maximum albedo and that VIC exhibits little improvement with a larger fresh snow albedo. There are remarkable differences in the vegetation impact on snow simulation for each snow model. In the presence of forest cover, SSiB shows a substantial increase in snow depth and SWE, Noah and VIC show a slight change though VIC experiences a later onset of snowmelt, and CLM3 has a reduction in its snow depth. Finally, we observe that a refined precipitation dataset significantly improves snow simulation, emphasizing the importance of accurate meteorological forcing for land surface modeling.
C1 [Feng, Xia; Houser, Paul] George Mason Univ, Dept Climate Dynam, Fairfax, VA 22030 USA.
[Sahoo, Alok] George Mason Univ, Ctr Earth Observing & Space Res, Fairfax, VA 22030 USA.
[Sahoo, Alok] Univ Maryland, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21201 USA.
[Houser, Paul; Luo, Yan] Ctr Res Environm & Water, Calverton, MD USA.
[Troy, Tara J.] Princeton Univ, Dept Civil & Environm, Princeton, NJ 08544 USA.
RP Feng, X (reprint author), IGES, COLA, 4041 Powder Mill Rd,Ste 302, Beltsville, MD 20705 USA.
EM xfeng@gmu.edu
RI Feng, Xia/K-1933-2013; Houser, Paul/J-9515-2013
OI Troy, Tara/0000-0001-5366-0633; Houser, Paul/0000-0002-2991-0441
NR 36
TC 31
Z9 31
U1 2
U2 10
PU AMER METEOROLOGICAL SOC
PI BOSTON
PA 45 BEACON ST, BOSTON, MA 02108-3693 USA
SN 1525-755X
J9 J HYDROMETEOROL
JI J. Hydrometeorol.
PD DEC
PY 2008
VL 9
IS 6
BP 1464
EP 1481
DI 10.1175/2008JHM860.1
PG 18
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 386DD
UT WOS:000261861600022
ER
PT J
AU Wojcik, R
Andreadis, K
Tedesco, M
Wood, E
Troy, T
Lettenmeier, D
AF Wojcik, Rafal
Andreadis, Konstantinos
Tedesco, Marco
Wood, Eric
Troy, Tara
Lettenmeier, Dennis
TI Multimodel Estimation of Snow Microwave Emission during CLPX 2003 Using
Operational Parameterization of Microphysical Snow Characteristics
SO JOURNAL OF HYDROMETEOROLOGY
LA English
DT Article
ID MODEL; HYDROLOGY; RANGE; MEDIA; SOIL
AB Existing forward snow emission models (SEMs) are limited by knowledge of both the temporal and spatial variability of snow microphysical parameters, with grain size being the most difficult to measure or estimate. This is due to the sparseness of in situ data and the lack of simple operational parameterizations for the evolution of snowpack properties. This paper compares snow brightness temperatures predicted by three SEMs using, as inputs, predicted snowpack characteristics from the Variable Infiltration Capacity (VIC) model. The latter is augmented by a new parameterization for the evolution of snow grain morphology and density. The grain size dynamics are described using a crystal growth equation. The three SEMs used in the study are the Land Surface Microwave Emission Model (LSMEM), the Dense Media Radiative Transfer (DMRT) model, and the Microwave Emission Model of Layered Snowpacks (MEMLS). Estimated brightness temperature is validated against the satellite [Advanced Microwave Scanning Radiometer for Earth Observing System (AMSR-E)] data at two sites from the Cold Land Processes Experiment (CLPX), conducted in Colorado in the winter of 2003. In addition, a merged multimodel estimate, based on Bayesian model averaging, is developed and compared to the measured brightness temperatures. The advantages of the Bayesian approach include the increase in the mean prediction accuracy as well as providing a nonparametric estimate of the error distributions for the brightness temperature estimates.
C1 [Andreadis, Konstantinos; Lettenmeier, Dennis] Univ Washington, Dept Civil & Environm Engn, Seattle, WA 98195 USA.
[Tedesco, Marco] Univ Maryland, Goddard Earth Sci & Technol Ctr, Baltimore, MD USA.
[Tedesco, Marco] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
[Wojcik, Rafal; Wood, Eric; Troy, Tara] Princeton Univ, Dept Civil & Environm Engn, Princeton, NJ 08544 USA.
RP Wojcik, R (reprint author), MIT, Dept Civil & Environm Engn, 77 Massachusetts Ave,Room 48-36, Cambridge, MA 02139 USA.
EM rwojcik@mit.edu
RI Tedesco, Marco/F-7986-2015;
OI Troy, Tara/0000-0001-5366-0633
FU Princeton University [NA04NES4400002]; University of Washington
[NA04NES4400003]
FX This research was possible through support from the NOAA Joint Center
for Satellite Data Assimilation (resulting in the Development of
Improved Forward Models for the Retrieval of Snow Properties using
EOS-era Satellites proposal) to Princeton University (Agreement
NA04NES4400002) and to the University of Washington (Agreement
NA04NES4400003). This support is gratefully acknowledged.
NR 27
TC 9
Z9 9
U1 0
U2 3
PU AMER METEOROLOGICAL SOC
PI BOSTON
PA 45 BEACON ST, BOSTON, MA 02108-3693 USA
SN 1525-755X
J9 J HYDROMETEOROL
JI J. Hydrometeorol.
PD DEC
PY 2008
VL 9
IS 6
BP 1491
EP 1505
DI 10.1175/2008JHM909.1
PG 15
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 386DD
UT WOS:000261861600024
ER
PT J
AU Shin, SJ
Cesnik, CES
Wilkie, WK
Wilbur, ML
AF Shin, Sang Joon
Cesnik, Carlos E. S.
Wilkie, W. Keats
Wilbur, Matthew L.
TI Design and Manufacturing of a Model-scale Active Twist Rotor Prototype
Blade
SO JOURNAL OF INTELLIGENT MATERIAL SYSTEMS AND STRUCTURES
LA English
DT Article
DE active twist rotor; blade integral actuation; piezoelectric composite
actuator; helicopter vibration control
ID REDUCTION; BEAMS
AB The design and manufacturing of an active twist rotor blade for vibration reduction in helicopters are presented. The rotor blade is integrally twisted by direct strain actuation through embedded piezoelectric fiber composite actuators distributed along the span of the blade. Highlights of the analysis formulation used to design this type of active blade are presented. The requirements for the prototype blade, along with the final design results are also presented. Detailed aspects of its manufacturing are described. Experimental structural characteristics of the prototype blade compare well with design goals, and bench actuation tests characterize its basic actuation performance. The design and manufacturing processes permit the realization of an active blade that satisfies a given set of design requirements. This is used to later develop a fully active rotor blade system.
C1 [Shin, Sang Joon] Seoul Natl Univ, Inst Adv Aerosp Technol, Seoul 151742, South Korea.
[Cesnik, Carlos E. S.] Univ Michigan, Dept Aerosp Engn, Ann Arbor, MI 48109 USA.
[Wilkie, W. Keats] NASA, Jet Prop Lab, Mech Syst Div, Pasadena, CA 91109 USA.
[Wilbur, Matthew L.] USA, Res Lab, NASA, Langley Res Ctr, Hampton, VA 23681 USA.
RP Shin, SJ (reprint author), Seoul Natl Univ, Inst Adv Aerosp Technol, Seoul 151742, South Korea.
EM ssjoon@snu.ac.kr
FU NASA [NCC 1-323]
FX The authors acknowledge the financial support and technical assistance
from Mr. Paul H. Mirick (formerly U. S. Army Vehicle Technology
Directorate, NASA Langley Research Center). The authors are also
thankful to Dr. John P. Rodgers (Starboard Innovation Inc.) for his
support to the blade fabrication, and to Mr. Gary Fleming and Ms. Emily
Pryputniewics (NASA Langley's Advanced Measurement and Diagnostics
Branch) for conducting the PMI tests. This work was sponsored by NASA
Langley Research Center under cooperative agreement NCC 1-323.
NR 38
TC 11
Z9 11
U1 0
U2 4
PU SAGE PUBLICATIONS LTD
PI LONDON
PA 1 OLIVERS YARD, 55 CITY ROAD, LONDON EC1Y 1SP, ENGLAND
SN 1045-389X
J9 J INTEL MAT SYST STR
JI J. Intell. Mater. Syst. Struct.
PD DEC
PY 2008
VL 19
IS 12
BP 1443
EP 1456
DI 10.1177/1045389X07088051
PG 14
WC Materials Science, Multidisciplinary
SC Materials Science
GA 375JP
UT WOS:000261110300007
ER
PT J
AU Yamakov, V
Saether, E
Glaessgen, EH
AF Yamakov, V.
Saether, E.
Glaessgen, E. H.
TI Multiscale modeling of intergranular fracture in aluminum: constitutive
relation for interface debonding
SO JOURNAL OF MATERIALS SCIENCE
LA English
DT Article; Proceedings Paper
CT 5th International Symposium on Ultrafine-Grained Materials
CY MAR 09-13, 2008
CL New Orleans, LA
ID MOLECULAR-DYNAMICS SIMULATION; METALS
AB Intergranular fracture is a dominant mode of failure in ultrafine grained materials. In the present study, the atomistic mechanisms of grain-boundary debonding during intergranular fracture in aluminum are modeled using a coupled molecular dynamics-finite element simulation. Using a statistical mechanics approach, a cohesive-zone law in the form of a traction-displacement constitutive relationship, characterizing the load transfer across the plane of a growing edge crack, is extracted from atomistic simulations and then recast in a form suitable for inclusion within a continuum finite element model. The cohesive-zone law derived by the presented technique is free of finite size effects and is statistically representative for describing the interfacial debonding of a grain boundary (GB) interface examined at atomic length scales. By incorporating the cohesive-zone law in cohesive-zone finite elements, the debonding of a GB interface can be simulated in a coupled continuum-atomistic model, in which a crack starts in the continuum environment, smoothly penetrates the continuum-atomistic interface, and continues its propagation in the atomistic environment. This study is a step toward relating atomistically derived decohesion laws to macroscopic predictions of fracture and constructing multiscale models for nanocrystalline and ultrafine grained materials.
C1 [Yamakov, V.] Natl Inst Aerosp, Hampton, VA 23666 USA.
[Saether, E.; Glaessgen, E. H.] NASA, Langley Res Ctr, Hampton, VA 23681 USA.
RP Yamakov, V (reprint author), Natl Inst Aerosp, Hampton, VA 23666 USA.
EM yamakov@nianet.org
NR 21
TC 14
Z9 16
U1 1
U2 16
PU SPRINGER
PI NEW YORK
PA 233 SPRING ST, NEW YORK, NY 10013 USA
SN 0022-2461
J9 J MATER SCI
JI J. Mater. Sci.
PD DEC
PY 2008
VL 43
IS 23-24
BP 7488
EP 7494
DI 10.1007/s10853-008-2823-7
PG 7
WC Materials Science, Multidisciplinary
SC Materials Science
GA 387LD
UT WOS:000261952800037
ER
PT J
AU Izumi, K
Cohen, EA
Setzer, KD
Fink, EH
Kawaguchi, K
AF Izumi, K.
Cohen, E. A.
Setzer, K. D.
Fink, E. H.
Kawaguchi, K.
TI Near-infrared Fourier-transform and millimeterwave spectra of the BiS
radical
SO JOURNAL OF MOLECULAR SPECTROSCOPY
LA English
DT Article
DE BiS radical; Rotational spectra; Near-infrared emission spectroscopy;
Hyperfine parameters; Relativistic effects
ID MICROWAVE SPECTROSCOPY; ELECTRONIC STATES; GASEOUS BIS; BISMUTH;
CONFIGURATION; FLUORESCENCE; CONSTANTS; BANDS
AB This paper reports the 6400-7400 cm(-1) Fourier-transform (FT) near-infrared (NIR) emission spectrum of the BiS X(2)(2)Pi(3/2) -> X(1)(2)Pi(1/2) fine structure bands as well as the millimeterwave rotational spectrum of the X(1)(2)Pi(1/2) state. For the FTNIR observations, BiS was produced by reaction of bismuth with sulfur vapor and excited by energy transfer from metastable oxygen, O(2)(a(1)Delta(g)), in a fast-flow system. As was the case for BiO [O. Shestakov, R. Breidohr, H. Demes, K.D. Setzer, E.H. Fink, J. Mol. Spectrosc. 190 (1998) 28-77], the 0.5 cm(-1) resolution spectrum revealed a number of strong bands in the Delta v = 0 and +/- 1 sequences which showed perturbed band spacings, band shapes, and intensities due to avoided crossing of the X(2)(2)Pi(3/2) and A(1)(4)Pi(3/2) potential curves for v' >= 4 of X(2)(2)Pi(3/2). The millimeterwave rotational spectrum of BiS in its X(1)(2)Pi(1/2) state was observed when BiS was produced in a high-temperature oven by a discharge in a mixture of Bi vapor and CS(2). The signal to noise ratio was markedly improved by using a White-type multi-path cell. Ninety seven features from J' = 23.5 to J' = 41.5 were measured between 150 and 300 GHz. Analysis of the 0.5 cm(-1) resolution FT spectrum yielded the fine structure splitting and vibrational constants of the states. A simultaneous analysis of millimeterwave and a 0.005 cm(-1) FT spectrum of the 0-0 band of the NIR system was carried out to give precise rotational, fine, and hyperfine constants for the X(1)(2)Pi(1/2) and X(2)(2)Pi(3/2) states. The results are consistent with those reported earlier for BiO and indicate only a slight decrease in the unpaired electron density in the 6p(pi*) orbital on the Bi atom. (C) 2008 Elsevier Inc. All rights reserved.
C1 [Izumi, K.; Kawaguchi, K.] Okayama Univ, Fac Sci, Dept Chem, Okayama 7008530, Japan.
[Cohen, E. A.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[Setzer, K. D.; Fink, E. H.] Berg Univ Wuppertal, Phys Chem Fachbereich C, D-42097 Wuppertal, Germany.
RP Kawaguchi, K (reprint author), Okayama Univ, Fac Sci, Dept Chem, Tsushima Naka 3-1-1, Okayama 7008530, Japan.
EM okakent@cc.okayama-u.ac.jp
RI Kawaguchi, Kentarou/B-1758-2011;
OI Kawaguchi, Kentarou/0000-0003-1067-1839; Setzer,
Klaus-Dieter/0000-0003-1275-0047
NR 30
TC 3
Z9 3
U1 1
U2 1
PU ACADEMIC PRESS INC ELSEVIER SCIENCE
PI SAN DIEGO
PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA
SN 0022-2852
J9 J MOL SPECTROSC
JI J. Mol. Spectrosc.
PD DEC
PY 2008
VL 252
IS 2
BP 198
EP 204
DI 10.1016/j.jms.2008.08.007
PG 7
WC Physics, Atomic, Molecular & Chemical; Spectroscopy
SC Physics; Spectroscopy
GA 382PV
UT WOS:000261618800013
ER
PT J
AU Kang, JH
Park, C
Lowther, SE
Harrison, JS
Park, CE
AF Kang, Jin Ho
Park, Cheol
Lowther, Sharon E.
Harrison, Joycelyn S.
Park, Chan Eon
TI All-Organic Actuator Fabricated with Single Wall Carbon Nanotube
Electrodes
SO JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS
LA English
DT Article
DE actuator; electrodes; high performance polymer; nanocomposite;
polyimide; single wall carbon nanotube
ID POLYMERIZATION; POLYPYRROLE; FILMS
AB Compliant electrodes to replace conventional metal electrodes have been required for many actuators to relieve the constraint on the electroactive layer. Many conducting polymers have been proposed for the alternative electrodes, but they still have a problem of poor thermal stability. This article reports a novel all-organic actuator with single wall carbon nanotube (SWCNT) films as an alternative electrode. The SWCNT film was obtained by filtering a SWCNT solution through an anodized alumina membrane. The conductivity of the SWCNT film was about 280 S/cm. The performance of the SWCNT film electrode was characterized by measuring the dielectric properties of NASA Langley Research Center - Electroactive Polymer (LaRC-EAP) sandwiched by the SWCNT electrodes over a broad range of temperature (from 25 to 280 degrees C) and frequency (from 1 kHz to 1 MHz). The all-organic actuator with the SWCNT electrodes showed a larger electric field-induced strain than that with metal electrodes, under identical measurement conditions. (C) 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 2532-2538, 2008
C1 [Kang, Jin Ho; Park, Cheol] Natl Inst Aerosp, Hampton, VA 23666 USA.
[Lowther, Sharon E.; Harrison, Joycelyn S.] NASA, Langley Res Ctr, Adv Mat & Proc Branch, Hampton, VA 23681 USA.
[Park, Chan Eon] Pohang Univ Sci & Technol, Dept Chem Engn, Polymer Res Inst, Pohang 790784, South Korea.
RP Park, C (reprint author), Natl Inst Aerosp, Hampton, VA 23666 USA.
EM cheol.park-1@nasa.gov
FU NASA University Research, Engineering and Technology Institute on Bio
Inspired Materials (BIMat) [NCC-1-02037]; Korea Science and Engineering
Foundation (KOSEF) [M01-2004-000-10344-0]
FX The authors thank Gregory K. Draughon and Nancy M. Holloway for their
help in preparation of the electrode-deposited film. Park and Kang
appreciate NASA University Research, Engineering and Technology
Institute on Bio Inspired Materials (BIMat) under award no. NCC-1-02037
for support in part. Kang appreciates the Postdoctoral Fellowship
Program of Korea Science and Engineering Foundation (KOSEF) under grant
no. M01-2004-000-10344-0 for support in part.
NR 16
TC 4
Z9 4
U1 0
U2 6
PU JOHN WILEY & SONS INC
PI HOBOKEN
PA 111 RIVER ST, HOBOKEN, NJ 07030 USA
SN 0887-6266
J9 J POLYM SCI POL PHYS
JI J. Polym. Sci. Pt. B-Polym. Phys.
PD DEC 1
PY 2008
VL 46
IS 23
BP 2532
EP 2538
DI 10.1002/polb.21601
PG 7
WC Polymer Science
SC Polymer Science
GA 382CJ
UT WOS:000261582300005
ER
PT J
AU Lu, J
Fang, ZZ
Choi, YJ
Sohn, HY
Kim, C
Bowman, RC
Hwang, SJ
AF Lu, Jun
Fang, Zhigang Zak
Choi, Young Joon
Sohn, Hong Yong
Kim, Chul
Bowman, Robert C., Jr.
Hwang, Son-Jong
TI The effect of heating rate on the reversible hydrogen storage based on
reactions of Li(3)AlH(6) with LiNH(2)
SO JOURNAL OF POWER SOURCES
LA English
DT Article
DE Hydrogenation; Dehydrogenation; Heating rate; Alanate; Amide
ID N-H SYSTEM; THERMAL-DECOMPOSITION; LIALH4; DEHYDROGENATION;
TRANSFORMATIONS; DESORPTION
AB Reversible dehydrogenation and hydrogenation reactions have been reported for a number of reactions based on lithium alanate and lithium amide materials. The dehydrogenation and hydrogenation reactions involving these materials are, however, usually very complex. Significant discrepancies exist among different studies published in literature. Understanding the reaction mechanism and the dependence of the reaction pathway on material preparation processes and processing parameters is critical. In this paper, the hydrogenation reactions of the mixture of 3Li(2)NH/Al/4 wt%TiCl(3) were investigated as a function of the heating rate. The hydrogenated products were characterized by means of TGA, XRD and solid-state NMR. These new results showed that the re-formation of Li(3)AlH(6) depends strongly on the heating rate during the hydrogenation process. The dehydrogenation and rehydrogenation reaction pathways and possible mechanisms of the combined system are, however, still under investigation. (C) 2008 Elsevier B.V. All rights reserved.
C1 [Lu, Jun; Fang, Zhigang Zak; Choi, Young Joon; Sohn, Hong Yong] Univ Utah, Dept Met Engn, Salt Lake City, UT 84112 USA.
[Kim, Chul; Hwang, Son-Jong] CALTECH, Div Chem & Chem Engn, Pasadena, CA 91125 USA.
[Bowman, Robert C., Jr.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Fang, ZZ (reprint author), Univ Utah, Dept Met Engn, 135 S 1460 E Room 412, Salt Lake City, UT 84112 USA.
EM zak.fang@utah.edu
FU U.S. Department of Energy (DOE) [DE-FC36-05GO15069, DE-Al-01-06EE11105];
jet Propulsion Laboratory; California Institute of Technology; National
Aeronautical and Space Administration (NASA); National Science
Foundation (NSF) [9724240]; MRSEC Program of the NSF [DMR-0520565]
FX This research was supported by the U.S. Department of Energy (DOE) under
contract numbers DE-FC36-05GO15069 (U. Utah) and DE-Al-01-06EE11105
(JPL) and was also partially performed at the jet Propulsion Laboratory,
California Institute of Technology, under a contract with the National
Aeronautical and Space Administration (NASA). The NIVIR facility at
Caltech was supported by the National Science Foundation (NSF) under
Grant Number 9724240 and partially supported by the MRSEC Program of the
NSF under award number DMR-0520565. We thank W. Luo and J. W. Reiter for
providing several Li-Mg-N-H reference materials.
NR 23
TC 8
Z9 8
U1 0
U2 4
PU ELSEVIER SCIENCE BV
PI AMSTERDAM
PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS
SN 0378-7753
J9 J POWER SOURCES
JI J. Power Sources
PD DEC 1
PY 2008
VL 185
IS 2
BP 1354
EP 1358
DI 10.1016/j.jpowsour.2008.07.040
PG 5
WC Chemistry, Physical; Electrochemistry; Energy & Fuels; Materials
Science, Multidisciplinary
SC Chemistry; Electrochemistry; Energy & Fuels; Materials Science
GA 384MM
UT WOS:000261748900110
ER
PT J
AU Azar, AE
Ghedira, H
Romanov, P
Mahani, S
Tedesco, M
Khanbilvardi, R
AF Azar, Amir E.
Ghedira, Hosni
Romanov, Peter
Mahani, Shayesteh
Tedesco, Marco
Khanbilvardi, Reza
TI Application of Satellite Microwave Images in Estimating Snow Water
Equivalent
SO JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION
LA English
DT Article
DE snow; snow depth; SWE; remote sensing; microwave
ID ALGORITHM
AB Flood forecast and water resource management requires reliable estimates of snow pack properties [snow depth and snow water equivalent (SWE)]. This study focuses on application of satellite microwave images to estimate the spatial distribution of snow depth and SWE over the Great Lakes area. To estimate SWE, we have proposed the algorithm which uses microwave brightness temperatures (Tb) measured by the Special Sensor Microwave Imager (SSM/I) radiometer along with information on the Normalized Difference Vegetation Index (NDVI).
The algorithm was developed and tested over 19 test sites characterized by different seasonal average snow depth and land cover type. Three spectral signatures derived from SSM/I data, namely T19V-T37V (GTV), T19H-T37H (GTH), and T22V-T85V (SSI), were examined for correlation with the snow depth and SWE. To avoid melting snow conditions, we have used observations taken only during the period from December 1-February 28. It was found that GTH, and GTV exhibit similar correlation with the snow depth/SWE and are most should be used over deep snowpack. In the same time, SSI is more sensitive to snow depth variations over a shallow snow pack. To account for the effect of dense forests on the scattering signal of snow we established the slope of the regression line between GTV and the snow depth as a function of NDVI. The accuracy of the new technique was evaluated through its comparison with ground-based measurements and with results of SWE analysis prepared by the National Operational Hydrological Remote Sensing Center (NOHRSC) of the National Weather Service. The proposed algorithm was found to be superior to previously developed global microwave SWE retrieval techniques.
C1 [Azar, Amir E.; Ghedira, Hosni; Mahani, Shayesteh; Khanbilvardi, Reza] CUNY, NOAA, CREST, New York, NY 10021 USA.
[Romanov, Peter] NOAA, NESDIS, Camp Springs, MD USA.
[Tedesco, Marco] NASA, Goddard Space Flight Ctr, Washington, DC USA.
RP Azar, AE (reprint author), CUNY, NOAA, CREST, 137th St & Convent Ave, New York, NY 10021 USA.
EM eazar@ce.cony.cuny.edu
RI Romanov, Peter/F-5622-2010; Tedesco, Marco/F-7986-2015
OI Romanov, Peter/0000-0002-2153-8307;
NR 17
TC 6
Z9 6
U1 0
U2 6
PU WILEY-BLACKWELL PUBLISHING, INC
PI MALDEN
PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA
SN 1093-474X
J9 J AM WATER RESOUR AS
JI J. Am. Water Resour. Assoc.
PD DEC
PY 2008
VL 44
IS 6
BP 1347
EP 1362
DI 10.1111/j.1752-1688.2008.00227.x
PG 16
WC Engineering, Environmental; Geosciences, Multidisciplinary; Water
Resources
SC Engineering; Geology; Water Resources
GA 378OO
UT WOS:000261334000001
ER
PT J
AU Wu, DL
Eckermann, SD
AF Wu, Dong L.
Eckermann, Stephen D.
TI Global Gravity Wave Variances from Aura MLS: Characteristics and
Interpretation
SO JOURNAL OF THE ATMOSPHERIC SCIENCES
LA English
DT Article
ID MICROWAVE LIMB SOUNDER; ATMOSPHERE RESEARCH SATELLITE; STRATOSPHERIC
MOUNTAIN WAVES; AMSU-A RADIANCES; MIDDLE ATMOSPHERE; LATITUDINAL
VARIATIONS; SOLVE/THESEO 2000; RADIOSONDE DATA; NUMBER SPECTRA; EOS MLS
AB The gravity wave (GW)-resolving capabilities of 118-GHz saturated thermal radiances acquired throughout the stratosphere by the Microwave Limb Sounder (MLS) on the Aura satellite are investigated and initial results presented. Because the saturated (optically thick) radiances resolve GW perturbations from a given altitude at different horizontal locations, variances are evaluated at 12 pressure altitudes between similar to 21 and 51 km using the 40 saturated radiances found at the bottom of each limb scan. Forward modeling simulations show that these variances are controlled mostly by GWs with vertical wavelengths lambda(z) > 5 km and horizontal along-track wavelengths of lambda(y) similar to 100-200 km. The tilted cigar-shaped three-dimensional weighting functions yield highly selective responses to GWs of high intrinsic frequency that propagate toward the instrument. The latter property is used to infer the net meridional component of GW propagation by differencing the variances acquired from ascending (A) and descending (D) orbits. Because of improved vertical resolution and sensitivity, Aura MLS GW variances are similar to 5-8 times larger than those from the Upper Atmosphere Research Satellite (UARS) MLS. Like UARS MLS variances, monthly-mean Aura MLS variances in January and July 2005 are enhanced when local background wind speeds are large, due largely to GW visibility effects. Zonal asymmetries in variance maps reveal enhanced GW activity at high latitudes due to forcing by flow over major mountain ranges and at tropical and subtropical latitudes due to enhanced deep convective generation as inferred from contemporaneous MLS cloud-ice data. At 21-28-km altitude ( heights not measured by the UARS MLS), GW variance in the tropics is systematically enhanced and shows clear variations with the phase of the quasi-biennial oscillation, in general agreement with GW temperature variances derived from radiosonde, rocketsonde, and limb-scan vertical profiles. GW-induced temperature variances at similar to 44-km altitude derived from operational global analysis fields of the ECMWF Integrated Forecast System in August 2006 reveal latitudinal bands of enhanced GW variance and preferred GW meridional propagation directions that are similar to those inferred from the MLS variances, highlighting the potential of MLS GW data for validating the stratospheric GWs simulated and/or parameterized in global models.
C1 [Wu, Dong L.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[Eckermann, Stephen D.] USN, Res Lab, Div Space Sci, Washington, DC 20375 USA.
RP Wu, DL (reprint author), CALTECH, Jet Prop Lab, M-S 183-701,4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM dong.l.wu@jpl.nasa.gov
RI Wu, Dong/D-5375-2012
FU NASA [NNH04ZYS004N]
FX This work was supported by NASA program NNH04ZYS004N ("Measurements,
Modeling, and Analyses in Support of Aura and Other Satellite
Observations of the Earth's Atmosphere"). DLW's research was performed
at the Jet Propulsion Laboratory (JPL), California Institute of
Technology under contract with the National Aeronautics and Space
Administration ( NASA) and supported by the NASA Aura project. SDE
acknowledges additional support from NASA's Geospace Sciences SR&T
Program. We thank the UK Met Office for providing stratospheric wind
analyses and the ECMWF for providing TL799L91 IFS analysis
data. Assistance from Dr. Evan Fishbein in accessing the ECMWF data is
also acknowledged. Finally, we thank the JPL MLS team for successful
instrument development, operation, and data processing, and three
anonymous reviewers for valuable comments on the original manuscript.
NR 73
TC 64
Z9 66
U1 3
U2 15
PU AMER METEOROLOGICAL SOC
PI BOSTON
PA 45 BEACON ST, BOSTON, MA 02108-3693 USA
SN 0022-4928
EI 1520-0469
J9 J ATMOS SCI
JI J. Atmos. Sci.
PD DEC
PY 2008
VL 65
IS 12
BP 3695
EP 3718
DI 10.1175/2008JAS2489.1
PG 24
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 387ZP
UT WOS:000261990400005
ER
PT J
AU Zhu, X
Yee, JH
Talaat, ER
Mlynczak, M
Russell, JM
AF Zhu, Xun
Yee, Jeng-Hwa
Talaat, E. R.
Mlynczak, M.
Russell, J. M., III
TI Diagnostic Analysis of Tidal Winds and the Eliassen-Palm Flux Divergence
in the Mesosphere and Lower Thermosphere from TIMED/SABER Temperatures
SO JOURNAL OF THE ATMOSPHERIC SCIENCES
LA English
DT Article
ID QUASI-BIENNIAL OSCILLATION; GENERALIZED HOUGH MODES; LONG-TERM
VARIABILITY; MIDDLE ATMOSPHERE; DIURNAL TIDE; MEAN FLOW;
SATELLITE-OBSERVATIONS; SABER EXPERIMENT; SPECTRAL MODEL; GRAVITY-WAVE
AB For migrating tides or fast-moving planetary waves, polarization relations derived from the linear wave equations are required to accurately derive the wind components from the temperature field. A common problem in diagnosing winds from the measured temperature is the error amplification associated with apparent singularities in the wave polarization relations. The authors have developed a spectral module that accurately derives tidal winds from the measured tidal temperature field and effectively eliminates the error amplification near the apparent singularities. The algorithm is used to perform a diagnostic analysis of tidal winds and the Eliassen-Palm (EP) flux divergence in the mesosphere and lower thermosphere (MLT) based on the zonal mean and tidal temperature fields derived from 6 yr of temperature measurements made by the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument onboard the Thermosphere-Ionosphere-Mesosphere Energetics and Dynamics ( TIMED) satellite. The derived zonal mean wind and diurnal tidal amplitude reveal new insights into the mesospheric biennial oscillation (MBO) that exists in the MLT at both equatorial and midlatitude regions. The equatorial MBO in the zonal mean wind is present in the entire mesosphere from 50 to 90 km. The equatorial MBO in the temperature amplitude of the diurnal tide occurs near the mesopause region between 80 and 90 km and is largely coincident with the downward phase propagation of the equatorial MBO in the zonal mean wind, indicating a possible mechanism of wave-mean flow interaction between the two. On the other hand, the newly discovered midlatitude MBOs in zonal mean wind and the meridional wind in diurnal tide occur at different altitudes, suggesting possibly a remote forcing-response relationship. The acceleration or deceleration of the zonal mean wind due to EP flux divergence that is contributed by the migrating tides peaks at mid-latitudes with a typical value of 10-20 m s(-1) day(-1) around 95 km.
C1 [Zhu, Xun; Yee, Jeng-Hwa; Talaat, E. R.] Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA.
[Mlynczak, M.] NASA, Langley Res Ctr, Hampton, VA 23665 USA.
[Russell, J. M., III] Hampton Univ, Ctr Atmospher Sci, Hampton, VA 23668 USA.
RP Zhu, X (reprint author), Johns Hopkins Univ, Appl Phys Lab, 11100 Johns Hopkins Rd, Laurel, MD 20723 USA.
EM xun.zhu@jhuapl.edu
RI Mlynczak, Martin/K-3396-2012; Zhu, Xun/C-2097-2016
OI Zhu, Xun/0000-0001-7860-6430
FU NASA [NAS5-97179, NNG05GG57G]; NSF [ATM-0730158]
FX Helpful comments by two anonymous reviewers are greatly appreciated.
This research was supported by the TIMED project sponsored by NASA under
contract NAS5-97179, NASA Grant NNG05GG57G, and in part by NSF Grant
ATM-0730158 to The Johns Hopkins University Applied Physics Laboratory.
NR 65
TC 9
Z9 10
U1 0
U2 2
PU AMER METEOROLOGICAL SOC
PI BOSTON
PA 45 BEACON ST, BOSTON, MA 02108-3693 USA
SN 0022-4928
EI 1520-0469
J9 J ATMOS SCI
JI J. Atmos. Sci.
PD DEC
PY 2008
VL 65
IS 12
BP 3840
EP 3859
DI 10.1175/2008JAS2801.1
PG 20
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 387ZP
UT WOS:000261990400012
ER
PT J
AU Zeng, XP
Tao, WK
Simpson, J
AF Zeng, Xiping
Tao, Wei-Kuo
Simpson, Joanne
TI A Set of Prognostic Variables for Long-Term Cloud-Resolving Model
Simulations
SO JOURNAL OF THE METEOROLOGICAL SOCIETY OF JAPAN
LA English
DT Article
ID ADVECTION-CONDENSATION PROBLEM; BULK ICE SCHEME; THERMODYNAMIC
FOUNDATION; MOIST ATMOSPHERE; CUMULUS CLOUDS; MICROPHYSICS;
SUPERSATURATION; RADIATION; DYNAMICS
AB A set of independent prognostic variables, based on a survey of the microphysical timescales in clouds, is proposed for long-term cloud-resolving model simulations. Two of the variables are the moist entropy and the total mixing ratio of airborne water with no contributions from precipitating particles. Non-prognostic variables such as air temperature can be diagnosed from the prognostic variables easily. In this proposed modeling framework, moist thermodynamics is separated (or modularized) from cloud dynamics and microphysics. Numerical results are compared with analytic solutions to show that the proposed prognostic variables work well when a large time step (e.g., 10 s) is used for numerical integration.
C1 [Zeng, Xiping; Tao, Wei-Kuo; Simpson, Joanne] NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA.
[Zeng, Xiping] Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21228 USA.
RP Zeng, XP (reprint author), NASA, Goddard Space Flight Ctr, Atmospheres Lab, Mail Code 613-1, Greenbelt, MD 20771 USA.
EM zeng@agnes.gsfc.nasa.gov
NR 33
TC 2
Z9 2
U1 0
U2 4
PU METEOROLOGICAL SOC JAPAN
PI TOKYO
PA C/O JAPAN METEOROLOGICAL AGENCY 1-3-4 OTE-MACHI, CHIYODA-KU, TOKYO,
100-0004, JAPAN
SN 0026-1165
EI 2186-9057
J9 J METEOROL SOC JPN
JI J. Meteorol. Soc. Jpn.
PD DEC
PY 2008
VL 86
IS 6
BP 839
EP 856
PG 18
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 412LR
UT WOS:000263726800001
ER
PT J
AU Mishchenko, MI
AF Mishchenko, Michael I.
TI Broadband electromagnetic scattering by particles
SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND
VISION
LA English
DT Article
ID SUM-RULES; PHYSICAL LIMITATIONS; OPTICAL MOMENTS; EXTINCTION;
ABSORPTION; SPHERES
AB The so-called sum rule for the extinction cross section has been the subject of several publications. However, it has not been obtained directly from the macroscopic Maxwell equations but rather follows from heuristic causality considerations. It is argued that these causality considerations are, in fact, questionable and do not follow from the fundamental concept of electromagnetic scattering by a particle. Therefore, the resulting sum rule should be considered an unproven hypothesis rather than an outcome of a rigorous derivation from first principles.
C1 NASA, Goddard Inst Space Studies, New York, NY 10025 USA.
RP Mishchenko, MI (reprint author), NASA, Goddard Inst Space Studies, 2880 Broadway, New York, NY 10025 USA.
EM mmishchenko@giss.nasa.gov
RI Mishchenko, Michael/D-4426-2012
FU NASA Radiation Sciences Program managed by Hal Maring
FX I thank Michael Kahnert and Daniel Mackowski for helpful comments on the
initial version of this paper. This research was funded by the NASA
Radiation Sciences Program managed by Hal Maring.
NR 19
TC 5
Z9 5
U1 0
U2 5
PU OPTICAL SOC AMER
PI WASHINGTON
PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA
SN 1084-7529
J9 J OPT SOC AM A
JI J. Opt. Soc. Am. A-Opt. Image Sci. Vis.
PD DEC
PY 2008
VL 25
IS 12
BP 2893
EP 2895
DI 10.1364/JOSAA.25.002893
PG 3
WC Optics
SC Optics
GA 388MC
UT WOS:000262022900001
PM 19037377
ER
PT J
AU Greenfield, DI
Marin, R
Doucette, GJ
Mikulski, C
Jones, K
Jensen, S
Roman, B
Alvarado, N
Feldman, J
Scholin, C
AF Greenfield, Dianne I.
Marin, Roman, III
Doucette, Gregory J.
Mikulski, Christina
Jones, Kelly
Jensen, Scott
Roman, Brent
Alvarado, Nilo
Feldman, Jason
Scholin, Chris
TI Field applications of the second-generation Environmental Sample
Processor (ESP) for remote detection of harmful algae: 2006-2007
SO LIMNOLOGY AND OCEANOGRAPHY-METHODS
LA English
DT Article
AB We assess the application of the second-generation Environmental Sample Processor (ESP) for the detection of harmful algal bloom (HAB) species in field and laboratory settings using two molecular probe techniques: a sandwich hybridization assay (SHA) and fluorescent in situ hybridization (FISH). During spring 2006, the first time this new instrument was deployed, the ESP successfully automated application of DNA probe arrays for various HAB species and other planktonic taxa, but non-specific background binding on the SHA probe array support made results interpretation problematic. Following 2006, the DNA array support membrane that we were using was replaced with a different membrane, and the SHA chemistry was adjusted. The sensitivity and dynamic range of these modifications were assessed using 96-well plate and ESP array SHA formats for several HAB species found commonly in Monterey Bay over a range of concentrations; responses were significantly correlated (p < 0.01). Modified arrays were deployed in 2007. Compared to 2006, probe arrays showed improved signal: noise, and remote detection of various HAB species was demonstrated. We confirmed that the ESP and affiliated assays can detect HAB populations at levels below those posing human health concerns, and results can be related to prevailing environmental conditions in near real-time.
C1 [Greenfield, Dianne I.] Univ S Carolina, Belle W Baruch Inst Marine & Coastal Sci, Charleston, SC 29412 USA.
[Marin, Roman, III; Jensen, Scott; Roman, Brent; Scholin, Chris] Monterey Bay Aquarium Res Inst, Moss Landing, CA 95039 USA.
[Doucette, Gregory J.; Mikulski, Christina; Jones, Kelly; Alvarado, Nilo] Natl Ocean Serv, NOAA, Marine Biotoxins Program, Charleston, SC 29412 USA.
[Feldman, Jason] NASA, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Greenfield, DI (reprint author), Univ S Carolina, Belle W Baruch Inst Marine & Coastal Sci, 331 Ft Johnson Rd, Charleston, SC 29412 USA.
EM dgreenfield@belle.baruch.sc.edu
RI Doucette, Gregory/M-3283-2013
FU Monterey Bay Aquarium Research Institute; David and Lucille Packard
Foundation; National Science Foundation; National Aeronautics and Space
Administration [OCE-0314222, CCF424599, NNG06GB34G, OCE-0314089]
FX We thank the engineering technicians and machinists at MBARI for their
invaluable help and dedication toward instrument development. We also
greatly appreciate the hard work and dedication from the crew of the R/V
Zephyr and Moss Landing Marine Laboratory, Small Boat Operations, and
help from Drs. W. Jones and C. Preston. The authors gratefully
acknowledge Drs. Z. Wang and T. Roth for the extraction and analysis of
domoic acid in discrete water samples. This project was funded in part
by the Monterey Bay Aquarium Research Institute from funds allocated by
the David and Lucille Packard Foundation, the National Science
Foundation, and the National Aeronautics and Space Administration
(OCE-0314222, CCF424599, and NNG06GB34G to CAS, and OCE-0314089 to GJD).
NR 43
TC 37
Z9 37
U1 3
U2 20
PU AMER SOC LIMNOLOGY OCEANOGRAPHY
PI WACO
PA 5400 BOSQUE BLVD, STE 680, WACO, TX 76710-4446 USA
SN 1541-5856
J9 LIMNOL OCEANOGR-METH
JI Limnol. Oceanogr. Meth.
PD DEC
PY 2008
VL 6
BP 667
EP 679
PG 13
WC Limnology; Oceanography
SC Marine & Freshwater Biology; Oceanography
GA V19FQ
UT WOS:000208058700004
ER
PT J
AU Springman, KR
Short, JW
Lindeberg, MR
Maselko, JM
Khan, C
Hodson, PV
Rice, SD
AF Springman, Kathrine R.
Short, Jeffrey W.
Lindeberg, Mandy R.
Maselko, Jacek M.
Khan, Colin
Hodson, Peter V.
Rice, Stanley D.
TI Semipermeable membrane devices link site-specific contaminants to
effects: Part 1-Induction of CYP1A in rainbow trout from contaminants in
Prince William Sound, Alaska
SO MARINE ENVIRONMENTAL RESEARCH
LA English
DT Article
DE SPMD; Oil spill; CYP1A; Complex mixture; Assessment; EROD; Creosote;
Biomarker; Trout; Induction potential; Lingering oil; Effects
ID POLYCYCLIC AROMATIC-HYDROCARBONS; EXXON-VALDEZ OIL; PERSISTENT ORGANIC
POLLUTANTS; WESTERN MEDITERRANEAN-SEA; POLYCHLORINATED-BIPHENYLS;
ONCORHYNCHUS-MYKISS; SALMO-GAIRDNERI; MILL EFFLUENTS; SPILL SITES;
CRUDE-OIL
AB Extracts from semi-permeable membrane devices (SPMDs) deployed on beaches in Prince William Sound (PWS), Alaska, were used to evaluate if complex contaminant mixtures from different sources can be distinguished by the resulting cytochrome P450 1A (CYP1A) activity in exposed test animals. Deployment sites included canneries, salmon hatcheries, and beaches where lingering oil remains from discharges during the 1964 earthquake or the 1989 Exxon Valdez oil spill. Other sites were selected at random to evaluate region-wide contaminant inputs or were located in salmon streams to evaluate contaminants carried and released by migrating salmon carcasses following reproduction. Following standard deployments of approximately 28 cl, an aliquot of the accumulated contaminants was intraperitoneally injected without cleanup into juvenile rainbow trout (Oncorhynchus mykiss). After 2 d and 7 cl, the activity of CYP1A was measured by the ethoxyresorufin-o-deethylase (EROD) assay. Exposure to extracts from the oiled sites and one hatchery site with numerous creosote pilings elicited strong EROD responses, whereas fish exposed to salmon stream extracts elicited weak but significant responses during late summer compared to late spring. Responses from the other sites were not significant, indicating contaminants from these sources are unlikely to cause CYP1A induction in resident biota. Rather than simply assessing extant contaminants, this method evaluates the potency of the different sites for bringing about aryl hydrocarbon receptor responses in resident biota. (C) 2008 Elsevier Ltd. All rights reserved.
C1 [Springman, Kathrine R.] Univ Calif Davis, Davis, CA 95616 USA.
[Short, Jeffrey W.; Lindeberg, Mandy R.; Maselko, Jacek M.; Rice, Stanley D.] NOAA, Alaska Fisheries Sci Ctr, Natl Marine Fisheries Serv, Juneau, AK 99801 USA.
[Khan, Colin; Hodson, Peter V.] Queens Univ, Kingston, ON K7L 3N6, Canada.
RP Springman, KR (reprint author), POB 315, Littleriver, CA 92456 USA.
EM krspringman@gmail.com
RI surname, name/A-2183-2010
FU Exxon Valdez Oil Spill Trustee Council
FX This study was supported in part by the Exxon Valdez Oil Spill Trustee
Council, but the findings and conclusions are those of the authors and
do not necessarily reflect the views or positions of the Council.
Mention of products or services herein does not imply endorsement by the
US government.
NR 71
TC 14
Z9 14
U1 0
U2 23
PU ELSEVIER SCI LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND
SN 0141-1136
EI 1879-0291
J9 MAR ENVIRON RES
JI Mar. Environ. Res.
PD DEC
PY 2008
VL 66
IS 5
BP 477
EP 486
DI 10.1016/j.marenvres.2008.07.001
PG 10
WC Environmental Sciences; Marine & Freshwater Biology; Toxicology
SC Environmental Sciences & Ecology; Marine & Freshwater Biology;
Toxicology
GA 379AW
UT WOS:000261367900001
PM 18845333
ER
PT J
AU Short, JW
Springman, KR
Lindeberg, MR
Holland, LG
Larsen, ML
Sloan, CA
Khan, C
Hodson, PV
Rice, SD
AF Short, Jeffrey W.
Springman, Kathrine R.
Lindeberg, Mandy R.
Holland, Larry G.
Larsen, Marie L.
Sloan, Catherine A.
Khan, Colin
Hodson, Peter V.
Rice, Stanley D.
TI Semipermeable membrane devices link site-specific contaminants to
effects: PART II - A comparison of lingering Exxon Valdez oil with other
potential sources of CYP1A inducers in Prince William Sound, Alaska
SO MARINE ENVIRONMENTAL RESEARCH
LA English
DT Article
DE Pollution monitoring; Oil spills; Sources; PAH; PCB; SPMD
ID POLYCYCLIC AROMATIC-HYDROCARBONS; CRUDE-OIL; ORGANIC POLLUTANTS; SEA
OTTER; SEDIMENTS; SPILL; FISH; GULF; INDUCTION; TISSUES
AB We deployed semipermeable membrane devices (SPMDs) on beaches for 28 days at 53 sites in Prince William Sound (PWS), Alaska, to evaluate the induction potential from suspected sources of cytochrome P450 1A(CYP1A)-inducing contaminants. Sites were selected to assess known point sources, or were chosen randomly to evaluate the region-wide sources. After deployment, SPMD extracts were analyzed chemically for persistent organic pollutants (POPs) and polycyclic aromatic hydrocarbons (PAH). These results were compared with hepatic CYP1A enzyme activity of juvenile rainbow trout injected with the same extracts priorto clean-up for the chemical analyses. Increased CYP1A activity was strongly associated with PAH concentrations in extracts, especially chrysene homologues but was not associated with POPs. The only apparent sources of chrysene homologues were lingering oil from Exxon Valdez, asphalt and bunker fuels released from storage tanks during the 1964 Alaska earthquake, creosote leaching from numerous pilings at one site, and PAH-contaminated sediments at Cordova Harbor. Our results indicate that PWS is remarkably free of pollution from PAH when nearby sources are absent as well as from pesticides and PCBs generally. Published by Elsevier Ltd.
C1 [Short, Jeffrey W.; Lindeberg, Mandy R.; Holland, Larry G.; Larsen, Marie L.; Rice, Stanley D.] NOAA, Alaska Fisheries Sci Ctr, Natl Marine Fisheries Serv, Juneau, AK 99801 USA.
[Springman, Kathrine R.] Univ Calif Davis, Davis, CA 95616 USA.
[Sloan, Catherine A.] NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Seattle, WA 98112 USA.
[Khan, Colin; Hodson, Peter V.] Queens Univ, Kingston, ON K7L 3N6, Canada.
RP Short, JW (reprint author), NOAA, Alaska Fisheries Sci Ctr, Natl Marine Fisheries Serv, 17109 Point Lena Loop Rd, Juneau, AK 99801 USA.
EM Jeff.Short@noaa.gov; krspringman@gmail.com
FU Exxon Valdez Oil Spill Trustee Council
FX This study was supported in part by the Exxon Valdez Oil Spill Trustee
Council, but the findings and conclusions are those of the authors and
do not necessarily reflect the views or positions of the Council.
Mention of products or services herein does not imply endorsement by the
US government.
NR 45
TC 17
Z9 17
U1 0
U2 19
PU ELSEVIER SCI LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND
SN 0141-1136
EI 1879-0291
J9 MAR ENVIRON RES
JI Mar. Environ. Res.
PD DEC
PY 2008
VL 66
IS 5
BP 487
EP 498
DI 10.1016/j.marenvres.2008.08.007
PG 12
WC Environmental Sciences; Marine & Freshwater Biology; Toxicology
SC Environmental Sciences & Ecology; Marine & Freshwater Biology;
Toxicology
GA 379AW
UT WOS:000261367900002
PM 18845332
ER
PT J
AU Payne, JR
Driskell, WB
Short, JW
Larsen, ML
AF Payne, James R.
Driskell, William B.
Short, Jeffrey W.
Larsen, Marie L.
TI Long term monitoring for oil in the Exxon Valdez spill region
SO MARINE POLLUTION BULLETIN
LA English
DT Article
DE PAH monitoring; Prince William Sound; Mytilus trossulus; LTEMP; Exxon
Valdez oil spill; Alaska; Oil tanker
ID SEA-SURFACE MICROLAYER; PRINCE-WILLIAM-SOUND; POLYCYCLIC
AROMATIC-HYDROCARBONS; PHOTOENHANCED TOXICITY; PUGET-SOUND; PORT-VALDEZ;
CRUDE-OIL; ALASKA; SEDIMENTS; MUSSELS
AB In the aftermath of the 1989 Exxon Valdez oil spill, a Long Term Environmental Monitoring Program (LTEMP) has been regularly sampling mussels (and some sediments) for polycyclic aromatic and saturated hydrocarbons (PAH and SHC) at sites in Port Valdez, Prince William Sound, and the nearby Gulf of Alaska region. After 1999, a decreasing trend appears in total PAH (TPAH) in tissues at all sites with current values below 100 ng/g dry weight (many below 50 ng/g). Currently, most samples reflect a predominantly dissolved-phase signal. This new low in TPAH likely represents ambient background levels. Synchrony in TPAH time-series and similarities in the hydrocarbon signatures portray regional-scale dynamics. The five inner Prince William Sound sites show similar composition and fluctuations that are different from the three Gulf of Alaska sites. The two Port Valdez sites represent a unique third region primarily influenced by the treated ballast water discharge from the Alyeska Marine Terminal. Prince William Sound has reverted to a stable environment of extremely low level contamination in which local perturbations are easily detected. (C) 2008 Elsevier Ltd. All rights reserved.
C1 [Payne, James R.] Payne Environm Consultants Inc, Encinitas, CA 92024 USA.
[Short, Jeffrey W.; Larsen, Marie L.] NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Ted Stevens Marine Res Inst, Juneau, AK 99801 USA.
RP Payne, JR (reprint author), Payne Environm Consultants Inc, 1991 Village Pk Way,Suite 206 B, Encinitas, CA 92024 USA.
EM jrpayne@sbcglobal.net
FU Exxon Valdez Trustee Council
FX We wish to thank the Prince William Sound Regional Citizens' Advisory
Council for their continued support along with partial funding from the
Exxon Valdez Trustee Council. The results presented here solely reflect
our interpretations of the data and not necessarily those of the funding
partners. We are especially grateful for the camaraderie, patience, and
managerial skills of Lisa Ka'aihue, the versatility and field support of
David Janka and crew of the R/V Auklet, the due efforts of our
predecessors - the KLI/GERG team, and the forbearance from our
respective families.
NR 51
TC 30
Z9 30
U1 0
U2 34
PU PERGAMON-ELSEVIER SCIENCE LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
SN 0025-326X
EI 1879-3363
J9 MAR POLLUT BULL
JI Mar. Pollut. Bull.
PD DEC
PY 2008
VL 56
IS 12
BP 2067
EP 2081
DI 10.1016/j.marpolbul.2008.07.014
PG 15
WC Environmental Sciences; Marine & Freshwater Biology
SC Environmental Sciences & Ecology; Marine & Freshwater Biology
GA 388AF
UT WOS:000261992000025
PM 18835610
ER
PT J
AU Deshpande, AD
Doyle, SA
Dockum, BW
Tesolin-Gee, A
AF Deshpande, Ashok D.
Doyle, Scott A.
Dockum, Bruce W.
Tesolin-Gee, Amy
TI Organochlorine contaminants in the muscle of striped bass illegally
harvested from shad gill nets in the Hudson River Estuary
SO MARINE POLLUTION BULLETIN
LA English
DT Article
ID POLYCHLORINATED-BIPHENYLS; HABITAT USE; PCB; ACCUMULATION
C1 [Deshpande, Ashok D.; Dockum, Bruce W.; Tesolin-Gee, Amy] Natl Marine Fisheries Serv, Sandy Hook Lab, Highlands, NJ 07732 USA.
[Doyle, Scott A.] Natl Marine Fisheries Serv, Brielle, NJ 08730 USA.
RP Deshpande, AD (reprint author), Natl Marine Fisheries Serv, Sandy Hook Lab, Highlands, NJ 07732 USA.
EM ashok.deshpande@noaa.gov
NR 39
TC 0
Z9 0
U1 1
U2 4
PU PERGAMON-ELSEVIER SCIENCE LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
SN 0025-326X
EI 1879-3363
J9 MAR POLLUT BULL
JI Mar. Pollut. Bull.
PD DEC
PY 2008
VL 56
IS 12
BP 2088
EP 2093
DI 10.1016/j.marpolbul.2008.09.005
PG 6
WC Environmental Sciences; Marine & Freshwater Biology
SC Environmental Sciences & Ecology; Marine & Freshwater Biology
GA 388AF
UT WOS:000261992000027
PM 18976784
ER
PT J
AU Hatamleh, O
Rivero, IV
Maredia, A
AF Hatamleh, Omar
Rivero, Iris V.
Maredia, Arif
TI Residual Stresses in Friction-Stir-Welded 2195 and 7075 Aluminum Alloys
SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND
MATERIALS SCIENCE
LA English
DT Article
ID FATIGUE-CRACK-GROWTH; JOINTS
AB Surface residual stresses (RSs) were characterized along friction-stir-welded 2195 and 7075 aluminum alloy (AA) plates. The surface measurements were obtained through X-ray diffraction (XRD) at five different locations along the weld. Each location consisted of several regions across the welded plate including the weld nugget, thermomechanically affected zone (TMAZ), heat-affected zone (HAZ), and base material. Measurements revealed that RSs were not uniform along the welded plate, with the highest RSs obtained on the middle of the plate. The RSs across the weld were also asymmetric relative to the weld centerline, with RSs as high as 231 MPa in the TMAZ for the retreating side of the weld.
C1 [Hatamleh, Omar] NASA, Lyndon B Johnson Space Ctr, Struct Branch, Houston, TX 77058 USA.
[Rivero, Iris V.; Maredia, Arif] Texas Tech Univ, Dept Ind Engn, Lubbock, TX 79409 USA.
RP Hatamleh, O (reprint author), NASA, Lyndon B Johnson Space Ctr, Struct Branch, Houston, TX 77058 USA.
EM omar.hatamleh-1@nasa.gov
NR 22
TC 12
Z9 13
U1 3
U2 13
PU SPRINGER
PI NEW YORK
PA 233 SPRING ST, NEW YORK, NY 10013 USA
SN 1073-5623
J9 METALL MATER TRANS A
JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci.
PD DEC
PY 2008
VL 39A
IS 12
BP 2867
EP 2874
DI 10.1007/s11661-008-9657-4
PG 8
WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical
Engineering
SC Materials Science; Metallurgy & Metallurgical Engineering
GA 365AK
UT WOS:000260378100009
ER
PT J
AU Kondrashov, D
Sun, CJ
Ghil, M
AF Kondrashov, Dmitri
Sun, Chaojiao
Ghil, Michael
TI Data Assimilation for a Coupled Ocean-Atmosphere Model. Part II:
Parameter Estimation
SO MONTHLY WEATHER REVIEW
LA English
DT Article
ID ENSEMBLE KALMAN FILTER; NINO SOUTHERN-OSCILLATION; AIR-SEA INTERACTION;
TROPICAL PACIFIC; EL-NINO; CIRCULATION MODEL; ENSO; STATE; OCEANOGRAPHY;
SIMULATIONS
AB The parameter estimation problem for the coupled ocean-atmosphere system in the tropical Pacific Ocean is investigated using an advanced sequential estimator [i.e., the extended Kalman filter (EKF)]. The intermediate coupled model (ICM) used in this paper consists of a prognostic upper-ocean model and a diagnostic atmospheric model. Model errors arise from the uncertainty in atmospheric wind stress. First, the state and parameters are estimated in an identical-twin framework, based on incomplete and inaccurate observations of the model state. Two parameters are estimated by including them into an augmented state vector. Model-generated oceanic datasets are assimilated to produce a time-continuous, dynamically consistent description of the model's El Nino-Southern Oscillation (ENSO). State estimation without correcting erroneous parameter values still permits recovering the true state to a certain extent, depending on the quality and accuracy of the observations and the size of the discrepancy in the parameters. Estimating both state and parameter values simultaneously, though, produces much better results. Next, real sea surface temperatures observations from the tropical Pacific are assimilated for a 30-yr period (1975-2004). Estimating both the state and parameters by the EKF method helps to track the observations better, even when the ICM is not capable of simulating all the details of the observed state. Furthermore, unobserved ocean variables, such as zonal currents, are improved when model parameters are estimated. A key advantage of using this augmented-state approach is that the incremental cost of applying the EKF to joint state and parameter estimation is small relative to the cost of state estimation alone. A similar approach generalizes various reduced-state approximations of the EKF and could improve simulations and forecasts using large, realistic models.
C1 [Kondrashov, Dmitri] Univ Calif Los Angeles, Dept Atmospher & Ocean Sci, Los Angeles, CA 90095 USA.
[Sun, Chaojiao] NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Greenbelt, MD 20771 USA.
[Sun, Chaojiao] Univ Maryland, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21201 USA.
[Ghil, Michael] Ecole Normale Super, Dept Geosci, F-75231 Paris, France.
[Ghil, Michael] Ecole Normale Super, Meteorol Dynam Lab, CNRS & IPSL, F-75231 Paris, France.
RP Kondrashov, D (reprint author), Univ Calif Los Angeles, Dept Atmospher & Ocean Sci, 405 Hilgard Ave, Los Angeles, CA 90095 USA.
EM dkondras@atmos.ucla.edu
RI Sun, Chaojiao/A-9569-2011; Kondrashov, Dmitri/E-2067-2016
OI Sun, Chaojiao/0000-0002-7030-0485; Kondrashov,
Dmitri/0000-0002-3471-7275
FU NASA's Modeling, Analysis and Prediction ( MAP) [1281080]
FX It is a pleasure to thank I. Fukumori and J. D. Neelin for stimulating
discussions and concrete suggestions, and two anonymous reviewers for
constructive comments. The sea surface temperature (SST) data for
1975-2004 were obtained online at http://ingrid.ldeo.columbia.edu/,
while the ocean current data for 1993-2004 were obtained online at
http://www.oscar.noaa.gov/. This work was supported by NASA's Modeling,
Analysis and Prediction ( MAP) Program through Grant 1281080.
NR 55
TC 30
Z9 30
U1 0
U2 3
PU AMER METEOROLOGICAL SOC
PI BOSTON
PA 45 BEACON ST, BOSTON, MA 02108-3693 USA
SN 0027-0644
J9 MON WEATHER REV
JI Mon. Weather Rev.
PD DEC
PY 2008
VL 136
IS 12
BP 5062
EP 5076
DI 10.1175/2008MWR2544.1
PG 15
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 394SD
UT WOS:000262467000030
ER
PT J
AU Peek, AH
Griffith, BO
Underwood, LW
Hall, CM
Armstrong, CD
Spruce, JP
Ross, KW
AF Peek, Anne H.
Griffith, Bryon O.
Underwood, Lauren W.
Hall, Callie M.
Armstrong, C. Duane
Spruce, Joseph P.
Ross, Kenton W.
TI Stennis Space Center Uses NASA Remote Sensing Assets to Address Coastal
Gulf of Mexico Issues
SO PHOTOGRAMMETRIC ENGINEERING AND REMOTE SENSING
LA English
DT Article
C1 [Peek, Anne H.] NASA, Appl Res & Technol Project Off, Stennis Space Ctr, MS USA.
[Griffith, Bryon O.] US EPA, Gulf Mexico Program, Stennis Space Ctr, MS USA.
[Underwood, Lauren W.; Spruce, Joseph P.; Ross, Kenton W.] SSAI, Stennis Space Ctr, MS USA.
RP Peek, AH (reprint author), NASA, Appl Res & Technol Project Off, Bldg 3226, Stennis Space Ctr, MS USA.
EM anne.h.peek@nasa.gov; griffith.bryon@epa.gov;
lauren.w.underwood@nasa.gov; callie.m.hall@nasa.gov;
curtis.d.armstrong@nasa.gov; kenton.w.ross@nasa.gov
NR 0
TC 1
Z9 1
U1 0
U2 0
PU AMER SOC PHOTOGRAMMETRY
PI BETHESDA
PA 5410 GROSVENOR LANE SUITE 210, BETHESDA, MD 20814-2160 USA
SN 0099-1112
J9 PHOTOGRAMM ENG REM S
JI Photogramm. Eng. Remote Sens.
PD DEC
PY 2008
VL 74
IS 12
BP 1449
EP 1453
PG 5
WC Geography, Physical; Geosciences, Multidisciplinary; Remote Sensing;
Imaging Science & Photographic Technology
SC Physical Geography; Geology; Remote Sensing; Imaging Science &
Photographic Technology
GA 381PY
UT WOS:000261549600001
ER
PT J
AU Benoit, MR
Brown, RB
Todd, P
Nelson, ES
Klaus, DM
AF Benoit, M. R.
Brown, R. B.
Todd, P.
Nelson, E. S.
Klaus, D. M.
TI Buoyant plumes from solute gradients generated by non-motile Escherichia
coli
SO PHYSICAL BIOLOGY
LA English
DT Article
ID PROTEIN CRYSTAL-GROWTH; SPACE-FLIGHT; TRANSPORT PHENOMENA;
FLUID-DYNAMICS; MICROGRAVITY; MOTILITY; CELLS; CONVECTION; BACTERIA;
CLINOROTATION
AB The effect of hydrodynamic mixing in bacterial populations due to bacterial chemotaxis is a well-described phenomenon known as bioconvection. Here we report the observation of buoyant plumes that result in hydrodynamic mixing, but in contrast to bioconvection the plumes form in the absence of bacterial motility. We propose that the buoyant flow originates from solute gradients created by bacterial metabolism, similar to solute-induced buoyant flow around growing protein crystals. In our experiments, metabolically-active non-motile Escherichia coli were layered along the bottom of flat-bottomed containers. The E. coli consumed glucose in the medium creating a lighter fluid beneath a heavier fluid. The situation is an example of Rayleigh-Taylor instability, in which a lighter fluid pushes on a heavier one. We developed a numerical model to study the effect of E. coli nutrient consumption and by-product excretion on extracellular solute gradients. The model solutions showed reduced-density fluid along the bottom of the fluid domain leading to buoyant plumes, which were qualitatively similar to the experimental plumes. We also used scaling analyses to study the dependence of plume formation on container size and cell size, and to investigate the effect of reduced gravity, such as the microgravity conditions encountered during spaceflight.
C1 [Benoit, M. R.; Brown, R. B.; Todd, P.; Klaus, D. M.] Univ Colorado, Dept Aerosp Engn Sci, Boulder, CO 80309 USA.
[Nelson, E. S.] NASA, Glenn Res Ctr, Cleveland, OH 44135 USA.
RP Klaus, DM (reprint author), Univ Colorado, Dept Aerosp Engn Sci, Boulder, CO 80309 USA.
EM klaus@colorado.edu
NR 53
TC 7
Z9 7
U1 0
U2 7
PU IOP PUBLISHING LTD
PI BRISTOL
PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND
SN 1478-3967
J9 PHYS BIOL
JI Phys. Biol.
PD DEC
PY 2008
VL 5
IS 4
AR 046007
DI 10.1088/1478-3975/5/4/046007
PG 10
WC Biochemistry & Molecular Biology; Biophysics
SC Biochemistry & Molecular Biology; Biophysics
GA 385WD
UT WOS:000261843400009
PM 19075355
ER
PT J
AU Mishchenko, MI
Dlugach, JM
AF Mishchenko, Michael I.
Dlugach, Janna M.
TI Accuracy of the scalar approximation in computations of diffuse and
coherent backscattering by discrete random media
SO PHYSICAL REVIEW A
LA English
DT Article
DE approximation theory; light coherence; light polarisation; light
scattering; matrix algebra; random media
ID MULTIPLE-SCATTERING; POLARIZED-LIGHT; ENHANCED BACKSCATTERING;
WEAK-LOCALIZATION; PARTICLES; RATIOS; ERRORS; LAYER
AB We use numerically exact computer simulations of multiple scattering in physically realistic models of sparse discrete random media to quantify the errors of the scalar approximation (SA) in computations of coherent backscattering (CB) assuming that the incident light is unpolarized. We show that while the SA errors in the diffuse backscattered intensity are often small, those in the CB enhancement factor can reach 25% and often exceed 20%. We attribute this to the fact that the computation of the enhancement factor involves all diagonal elements of the diffuse backscattering Stokes matrix rather than only its (1, 1) element. Therefore, the coherent enhancement of backscattered intensity appears to be the result of a complex interplay of various polarization effects involved in the process of multiple scattering. Thus our numerical data make a strong case against the use of the SA in theoretical computations of CB in the case of unpolarized incident light.
C1 [Mishchenko, Michael I.] NASA, Goddard Inst Space Studies, New York, NY 10025 USA.
[Dlugach, Janna M.] Natl Acad Sci Ukraine, Main Astron Observ, UA-03680 Kiev, Ukraine.
RP Mishchenko, MI (reprint author), NASA, Goddard Inst Space Studies, 2880 Broadway, New York, NY 10025 USA.
EM mmishchenko@giss.nasa.gov
RI Mishchenko, Michael/D-4426-2012
FU NASA
FX This research was supported by the NASA Radiation Sciences Program.
NR 44
TC 4
Z9 4
U1 0
U2 2
PU AMER PHYSICAL SOC
PI COLLEGE PK
PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA
SN 2469-9926
EI 2469-9934
J9 PHYS REV A
JI Phys. Rev. A
PD DEC
PY 2008
VL 78
IS 6
AR 063822
DI 10.1103/PhysRevA.78.063822
PN B
PG 7
WC Optics; Physics, Atomic, Molecular & Chemical
SC Optics; Physics
GA 391OV
UT WOS:000262243500072
ER
PT J
AU Schmitt-Sody, A
Arissian, L
Velten, A
Diels, JC
Smith, DD
AF Schmitt-Sody, Andreas
Arissian, Ladan
Velten, Andreas
Diels, Jean-Claude
Smith, David D.
TI Rabi cycling of two pulses in a mode-locked ring laser cavity with
electro-optical control
SO PHYSICAL REVIEW A
LA English
DT Article
DE atom-photon collisions; electro-optical effects; laser cavity
resonators; laser mode locking; molecule-photon collisions; optical
control; quantum optics; ring lasers
ID PHASE-INTERACTION; BACKSCATTERING; GYRO
AB The intensities of the circulating pulses in a mode-locked ring laser are shown to be analogous to the population transfer (Rabi cycle) in a two-level system. We present an experimental demonstration of this analogy.
C1 [Schmitt-Sody, Andreas; Arissian, Ladan; Velten, Andreas; Diels, Jean-Claude] Univ New Mexico, Dept Phys & Astron, Albuquerque, NM 87106 USA.
[Schmitt-Sody, Andreas; Arissian, Ladan; Velten, Andreas; Diels, Jean-Claude] Ctr High Technol Mat, Albuquerque, NM 87106 USA.
[Smith, David D.] NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA.
RP Schmitt-Sody, A (reprint author), Univ New Mexico, Dept Phys & Astron, 800 Yale Blvd, Albuquerque, NM 87106 USA.
FU National Science Foundation [ECS-0601612]
FX This work was supported by the National Science Foundation under Grant
No. ECS-0601612.
NR 20
TC 1
Z9 1
U1 0
U2 0
PU AMER PHYSICAL SOC
PI COLLEGE PK
PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA
SN 1050-2947
J9 PHYS REV A
JI Phys. Rev. A
PD DEC
PY 2008
VL 78
IS 6
AR 063802
DI 10.1103/PhysRevA.78.063802
PG 6
WC Optics; Physics, Atomic, Molecular & Chemical
SC Optics; Physics
GA 391OV
UT WOS:000262243500052
ER
PT J
AU Knysh, S
Smelyanskiy, VN
AF Knysh, Sergey
Smelyanskiy, Vadim N.
TI Statistical mechanics of the quantum K-satisfiability problem
SO PHYSICAL REVIEW E
LA English
DT Article
DE critical exponents; magnetic transitions; magnetisation; Monte Carlo
methods; quantum statistical mechanics; statistical distributions
ID ISING SPIN-GLASS; SHERRINGTON-KIRKPATRICK MODEL;
REPLICA-SYMMETRY-BREAKING; TRANSVERSE-FIELD; CRITICAL-BEHAVIOR; RANDOM
IMPURITIES; PHASE-TRANSITION; ZERO-TEMPERATURE; SOLVABLE MODEL; RANDOM
GRAPHS
AB We study the quantum version of the random K-satisfiability problem in the presence of an external magnetic field Gamma applied in the transverse direction. We derive the replica-symmetric free-energy functional within the static approximation and the saddle-point equation for the order parameter: the distribution P[h(m)] of functions of magnetizations. The order parameter is interpreted as the histogram of probability distributions of individual magnetizations. In the limit of zero temperature and small transverse fields, to leading order in Gamma magnetizations m approximate to 0 become relevant in addition to purely classical values of m approximate to +/- 1. Self-consistency equations for the order parameter are solved numerically using a quasi-Monte Carlo method for K=3. It is shown that for an arbitrarily small Gamma quantum fluctuations destroy the phase transition present in the classical limit Gamma=0, replacing it with a smooth crossover transition. The implications of this result with respect to the expected performance of quantum optimization algorithms via adiabatic evolution are discussed. The replica-symmetric solution of the classical random K-satisfiability problem is briefly reexamined. It is shown that the phase transition at T=0 predicted by the replica-symmetric theory is of continuous type with atypical critical exponents.
C1 [Knysh, Sergey] NASA, Ames Res Ctr, ELORET Corp, Moffett Field, CA 94035 USA.
RP Knysh, S (reprint author), NASA, Ames Res Ctr, ELORET Corp, MS 229-1, Moffett Field, CA 94035 USA.
EM Sergey.I.Knysh@nasa.gov; Vadim.N.Smelyanskiy@nasa.gov
NR 67
TC 3
Z9 3
U1 0
U2 1
PU AMER PHYSICAL SOC
PI COLLEGE PK
PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA
SN 2470-0045
EI 2470-0053
J9 PHYS REV E
JI Phys. Rev. E
PD DEC
PY 2008
VL 78
IS 6
AR 061128
DI 10.1103/PhysRevE.78.061128
PN 1
PG 23
WC Physics, Fluids & Plasmas; Physics, Mathematical
SC Physics
GA 391NP
UT WOS:000262240300040
PM 19256823
ER
PT J
AU Sridhar, B
Grabbe, SR
Mukherjee, A
AF Sridhar, Banavar
Grabbe, Shon R.
Mukherjee, Avijit
TI Modeling and Optimization in Traffic Flow Management
SO PROCEEDINGS OF THE IEEE
LA English
DT Article
DE Aggregate models; air traffic management; collaborative decision making;
complex systems; delay modeling; ground delay; large-scale optimization;
linear optimization; performance metrics; traffic flow management;
uncertainty; weather impacts
ID GROUND-HOLDING PROBLEM; COLLABORATIVE DECISION-MAKING; EQUITY
CONSIDERATIONS; KINEMATIC WAVES; CONSTRAINTS; ALGORITHMS; WORKLOAD;
HIGHWAY
AB Traffic flow management (TFM) allocates the various airport, airspace, and other resources to maintain an efficient traffic flow consistent with safety. TFM is a complex area of research involving the disciplines of operations research, guidance and control, human factors, and software engineering. Hundreds of human operators make TFM decisions that involve tens of thousands of aircraft, en route air traffic control centers, the Federal Aviation Administration's System Command Center, and many airline operation centers. This paper provides an overview of how TFM decisions are made today and challenges facing the system in the future, and reviews modeling and optimization approaches for facilitating system-wide modeling, performance assessments, and system-level optimization of the national airspace system in the presence of both en route and airport capacity constraints.
C1 [Sridhar, Banavar; Grabbe, Shon R.; Mukherjee, Avijit] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
RP Sridhar, B (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
NR 89
TC 24
Z9 25
U1 1
U2 20
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA
SN 0018-9219
EI 1558-2256
J9 P IEEE
JI Proc. IEEE
PD DEC
PY 2008
VL 96
IS 12
SI SI
BP 2060
EP 2080
DI 10.1109/JPROC.2008.2006141
PG 21
WC Engineering, Electrical & Electronic
SC Engineering
GA 401IQ
UT WOS:000262934800012
ER
PT J
AU Jones, WR
Jansen, MJ
AF Jones, W. R., Jr.
Jansen, M. J.
TI Tribology for space applications
SO PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART J-JOURNAL OF
ENGINEERING TRIBOLOGY
LA English
DT Article
DE space tribology; lubrication; perfluoropolyethers; Pennazne; Krytox;
Fomblin; Brayco; space mechanisms
ID VACUUM; LUBRICATION; MOS2; PERFLUOROPOLYETHERS; TEMPERATURE;
PERFORMANCE; MECHANISMS; BEARINGS; FILMS; OIL
AB Historically, space mechanism lubricant choices were based on space heritage rather than on the latest technology or best available materials. With the limited mission lives and minimal duty cycles of the early space programme, this strategy was highly successful. As missions extended, other spacecraft components, such as electronics, batteries, and computers, failed before lubricated mechanisms; however, during the 1980s and 1990s, these ancillary components vastly improved and tribological systems became a main factor limiting spacecraft reliability and performance. Although tribological components represent only a small fraction of the spacecraft's cost, they are often single-point failures that cripple or debilitate expensive spacecraft. This paper will discuss the following: common space lubricants, mechanism components, testing, and factors affecting lubricant selections.
C1 [Jones, W. R., Jr.] NASA, Glenn Res Ctr, Cleveland, OH 44135 USA.
[Jansen, M. J.] Univ Toledo, Dept Mech Engn, Toledo, OH USA.
RP Jones, WR (reprint author), NASA, Glenn Res Ctr, 21000 Brookpk Rd,Mailstop 23-2, Cleveland, OH 44135 USA.
EM wjones1940@gmail.com
NR 64
TC 15
Z9 17
U1 4
U2 24
PU PROFESSIONAL ENGINEERING PUBLISHING LTD
PI WESTMINISTER
PA 1 BIRDCAGE WALK, WESTMINISTER SW1H 9JJ, ENGLAND
SN 1350-6501
J9 P I MECH ENG J-J ENG
JI Proc. Inst. Mech. Eng. Part J.-J. Eng. Tribol.
PD DEC
PY 2008
VL 222
IS J8
BP 997
EP 1004
DI 10.1243/13506501JET305
PG 8
WC Engineering, Mechanical
SC Engineering
GA 388MK
UT WOS:000262023700002
ER
PT J
AU Kassis, M
Adams, JD
Hora, JL
Deutsch, LK
Tollestrup, EV
AF Kassis, Marc
Adams, Joseph D.
Hora, Joseph L.
Deutsch, Lynne K.
Tollestrup, Eric V.
TI MIRSI, A Mid-Infrared Spectrometer and Imager: Performance Results from
the IRTF
SO PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF THE PACIFIC
LA English
DT Article
ID SPECTRAL IRRADIANCE CALIBRATION; ARRAY CAMERA; ORION-NEBULA; ASTRONOMY;
EMISSION
AB The Mid-Infrared Spectrometer and Imager (MIRSI) is a mid-infrared camera system built at Boston University for ground-based observing. MIRSI offers complete spectral coverage over the atmospheric windows at 8-14 and 18-26 mu m for both imaging (discrete filters and a circular variable filter) and spectroscopy (in the 10 and 20 mu m windows with resolutions of lambda/Delta lambda = 200 and 100, respectively). The optical design was optimized for use at NASA's Infrared Telescope Facility (IRTF). MIRSI utilizes a 320 x 240 pixel detector array with a plate scale of 0.27 '' pixel(-1), covering a field-of-view of 86 '' x 63 '' at the IRTF. MIRSI's optics provide diffraction-limited spatial resolution, and the instrument achieves 1 sigma detection limits of 4 and 236 mJy at 10 and 21 mu m, respectively, in 60 s of on-source integration time.
C1 [Kassis, Marc] Keck Observ, Kamuela, HI USA.
[Adams, Joseph D.] Cornell Univ, Dept Astron, Ithaca, NY 14853 USA.
[Hora, Joseph L.; Deutsch, Lynne K.] Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA.
[Tollestrup, Eric V.] NASA, Infrared Telescope Facil, Hilo, HI USA.
RP Kassis, M (reprint author), Keck Observ, 65-1120 Mamalahoa Hwy, Kamuela, HI USA.
EM mkassis@keck.hawaii.edu; jdadams@astro.cornell.edu;
jhora@cfa.havard.edu; tolles@ifa.hawaii.edu
OI Hora, Joseph/0000-0002-5599-4650
FU Boston University; NSF [9876656]
FX We thank L. Bergknut, G. Koenig, S. J. Bus, and the IRTF telescope
operators W. Golisch, D. Griep, and P. Sears for their assistance at the
IRTF. We also acknowledge and thank J. Polizotti (SAO) for his design of
the telescope interface. Funding for this work was provided by Boston
University and the NSF Advanced Technologies Instrument Program (NSF
grant 9876656).
NR 20
TC 8
Z9 8
U1 0
U2 0
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0004-6280
J9 PUBL ASTRON SOC PAC
JI Publ. Astron. Soc. Pac.
PD DEC
PY 2008
VL 120
IS 874
BP 1271
EP 1281
DI 10.1086/595711
PG 11
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 385XS
UT WOS:000261847500003
ER
PT J
AU Ban, S
Buchanan, M
Cheeks, N
Funsten, H
Hawsey, R
Lane, M
Whitlow, W
Studt, T
AF Ban, Stephen
Buchanan, Michelle
Cheeks, Nona
Funsten, Herbert
Hawsey, Robert
Lane, Monya
Whitlow, Woodrow, Jr.
Studt, Tim
TI Tough Times Ahead for Government Labs
SO R&D MAGAZINE
LA English
DT Editorial Material
C1 [Ban, Stephen] Argonne Natl Lab, Argonne, IL 60439 USA.
[Buchanan, Michelle] Oak Ridge Natl Lab, Oak Ridge, TN USA.
[Cheeks, Nona] NASA, Goddard Space Flight Ctr, Innovat Partnerships Program Off, Greenbelt, MD 20771 USA.
[Funsten, Herbert] Los Alamos Natl Lab, ISR Technol Div, Los Alamos, NM USA.
[Hawsey, Robert] Natl Renewable Energy Lab, Golden, CO USA.
[Lane, Monya] Lawrence Livermore Natl Lab, Livermore, CA USA.
[Whitlow, Woodrow, Jr.] NASA, Glenn Res Ctr, Cleveland, OH USA.
[Studt, Tim] Adv Business Media, Lab Equipment Magazine, Elk Grove Village, IL USA.
RP Ban, S (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA.
RI Funsten, Herbert/A-5702-2015
OI Funsten, Herbert/0000-0002-6817-1039
NR 0
TC 0
Z9 0
U1 0
U2 1
PU ADVANTAGE BUSINESS MEDIA
PI ROCKAWAY
PA 100 ENTERPRISE DR, SUITE 600, BOX 912, ROCKAWAY, NJ 07866-0912 USA
SN 0746-9179
J9 R&D MAG
JI R D Mag.
PD DEC
PY 2008
VL 50
IS 7
BP 10
EP 12
PG 3
WC Engineering, Industrial; Multidisciplinary Sciences
SC Engineering; Science & Technology - Other Topics
GA 386SS
UT WOS:000261903500002
ER
PT J
AU Guise, JM
Deering, SH
Kanki, BG
Osterweil, P
Li, H
Mori, M
Lowe, NK
AF Guise, Jeanne-Marie
Deering, Shad H.
Kanki, Barbara G.
Osterweil, Patricia
Li, Hong
Mori, Motomi
Lowe, Nancy K.
TI Validation of a Tool to Measure and Promote Clinical Teamwork
SO SIMULATION IN HEALTHCARE-JOURNAL OF THE SOCIETY FOR SIMULATION IN
HEALTHCARE
LA English
DT Article
DE Validation study; Safety; Teamwork; Obstetrics; Health care; Patient
care team; Simulation; Quality assurance; Quality of care;
Interprofessional relations; Clinical competence
AB Objective: Human factors and teamwork are major contributors to sentinel events. A major limitation to improving human factors and teamwork is the paucity of objective validated measurement tools. Our goal was to develop a brief tool that could be used to objectively evaluate teamwork in the field during short clinical team simulations and in everyday clinical care.
Study Design: A pilot validation study. Standardized videos were created demonstrating poor, average, and excellent teamwork among an obstetric team in a common clinical scenario (shoulder dystocia). Three evaluators all trained in Crew Resource Management, and unaware of assigned teamwork level, independently reviewed videos and evaluated teamwork using the Clinical Teamwork Scale (CTS). Statistical analysis included calculation of the Kappa statistic and Kendall coefficient to evaluate agreement and score concordance among raters, and Interclass Correlation Coefficient (ICC) to evaluate interrater reliability. The reliability of the tool was further evaluated by estimating the variance of each component of the tool based on generalizability theory.
Results: There was substantial agreement (Kappa 0.78) and score concordance (Kendall coefficient 0.95) among raters, and excellent interrater reliability (interclass correlation coefficient 0.98). The highest percentage of variance in scores among raters was because of rater/item interaction.
Conclusion: The CTS was developed to efficiently measure key clinical teamwork skills during simulation exercises and in everyday clinical care. It contains 15 questions in 5 clinical teamwork domains (communication, situational awareness, decision-making, role responsibility, and patient friendliness). It is easy to use and has construct validity with median ratings consistently corresponding with the intended teamwork level. The CTS is a brief, straightforward, valid, reliable, and easy-to-use tool to measure key factors in teamwork in simulated and clinical settings. (Sim Healthcare 3: 217-223, 2008)
C1 [Guise, Jeanne-Marie] Oregon Hlth & Sci Univ, Dept Publ Hlth & Prevent, Portland, OR 97239 USA.
[Osterweil, Patricia] Oregon Hlth & Sci Univ, Dept OB GYN, Div Maternal Fetal Med, Portland, OR 97239 USA.
[Guise, Jeanne-Marie] Oregon Hlth & Sci Univ, Dept Med Informat & Clin Epidemiol, Portland, OR 97239 USA.
[Li, Hong; Mori, Motomi] Oregon Hlth & Sci Univ, Ctr Biostat, Portland, OR 97239 USA.
[Deering, Shad H.] Madigan Army Med Ctr, Anderson Simulat Ctr, Tacoma, WA 98431 USA.
[Kanki, Barbara G.] NASA, Ames Res Ctr, Human Syst Integrat Div, Moffett Field, CA 94035 USA.
[Lowe, Nancy K.] Univ Colorado Denver, Coll Nursing, Aurora, CO USA.
RP Guise, JM (reprint author), Oregon Hlth & Sci Univ, Dept Publ Hlth & Prevent, 3181 SW Sam Jackson Pk Rd,L466, Portland, OR 97239 USA.
EM guisej@ohsu.edu
NR 28
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U1 1
U2 13
PU LIPPINCOTT WILLIAMS & WILKINS
PI PHILADELPHIA
PA TWO COMMERCE SQ, 2001 MARKET ST, PHILADELPHIA, PA 19103 USA
SN 1559-2332
EI 1559-713X
J9 SIMUL HEALTHC
JI Simul. Healthc.
PD WIN
PY 2008
VL 3
IS 4
BP 217
EP 223
DI 10.1097/SIH.0b013e31816fdd0a
PG 7
WC Health Care Sciences & Services
SC Health Care Sciences & Services
GA V11MS
UT WOS:000207536300002
PM 19088666
ER
PT J
AU Sibeck, DG
Angelopoulos, V
AF Sibeck, D. G.
Angelopoulos, V.
TI THEMIS Science Objectives and Mission Phases
SO SPACE SCIENCE REVIEWS
LA English
DT Review
DE THEMIS; Magnetosphere; Substorms; Radiation belts; Magnetopause
ID FLUX-TRANSFER EVENTS; MAGNETOTAIL CURRENT SHEET; HIGH-SPEED FLOWS;
PLASMA SHEET; SUBSTORM ONSET; CURRENT DISRUPTION; BOUNDARY-LAYER;
SPACECRAFT OBSERVATIONS; MAGNETOPAUSE STRUCTURES; DAYSIDE MAGNETOPAUSE
AB The five THEMIS spacecraft and a dedicated ground-based observatory array will pinpoint when and where substorms occur, thereby providing the observations needed to identify the processes that cause substorms to suddenly release solar wind energy stored within the Earth's magnetotail. The primary science which drove the mission design enables unprecedented observations relevant to magnetospheric research areas ranging from the foreshock to the Earth's radiation belts. This paper describes how THEMIS will reach closure on its baseline scientific objectives as a function of mission phase.
C1 [Sibeck, D. G.] NASA, GSFC, Greenbelt, MD 20771 USA.
[Angelopoulos, V.] Univ Calif Los Angeles, IGPP, Los Angeles, CA 90095 USA.
RP Sibeck, DG (reprint author), NASA, GSFC, Code 674, Greenbelt, MD 20771 USA.
EM david.g.sibeck@nasa.gov; vassilis@ucla.edu
RI Sibeck, David/D-4424-2012
NR 101
TC 100
Z9 100
U1 1
U2 6
PU SPRINGER
PI DORDRECHT
PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS
SN 0038-6308
EI 1572-9672
J9 SPACE SCI REV
JI Space Sci. Rev.
PD DEC
PY 2008
VL 141
IS 1-4
BP 35
EP 59
DI 10.1007/s11214-008-9393-5
PG 25
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 389JP
UT WOS:000262089000003
ER
PT J
AU Ludlam, M
Angelopoulos, V
Taylor, E
Snare, RC
Means, JD
Ge, YS
Narvaez, P
Auster, HU
Le Contel, O
Larson, D
Moreau, T
AF Ludlam, M.
Angelopoulos, V.
Taylor, E.
Snare, R. C.
Means, J. D.
Ge, Y. S.
Narvaez, P.
Auster, H. U.
Le Contel, O.
Larson, D.
Moreau, T.
TI The THEMIS Magnetic Cleanliness Program
SO SPACE SCIENCE REVIEWS
LA English
DT Review
DE THEMIS; Magnetic cleanliness; Spacecraft cleanliness
AB The five identical THEMIS Spacecraft, launched in February 2007, carry two magnetometers on each probe, one DC fluxgate (FGM) and one AC search coil (SCM). Due to the small size of the THEMIS probes, and the short length of the magnetometer booms, magnetic cleanliness was a particularly complex task for this medium sized mission. The requirements leveled on the spacecraft and instrument design required a detailed approach, but one that did not hamper the development of the probes during their short design, production and testing phase. In this paper we describe the magnetic cleanliness program's requirements, design guidelines, program implementation, mission integration and test philosophy and present test results, and mission on-orbit performance.
C1 [Ludlam, M.; Angelopoulos, V.; Taylor, E.; Larson, D.; Moreau, T.] Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA.
[Angelopoulos, V.; Snare, R. C.; Means, J. D.; Ge, Y. S.] Univ Calif Los Angeles, IGPP ESS, Los Angeles, CA 90095 USA.
[Narvaez, P.] NASA JPL, Pasadena, CA 91109 USA.
[Auster, H. U.] TUBS, D-38106 Braunschweig, Germany.
[Le Contel, O.] CETP IPSL, F-78140 Velizy Villacoublay, France.
RP Ludlam, M (reprint author), Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA.
EM mludlam@ssl.berkeley.edu
NR 8
TC 6
Z9 8
U1 0
U2 4
PU SPRINGER
PI DORDRECHT
PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS
SN 0038-6308
J9 SPACE SCI REV
JI Space Sci. Rev.
PD DEC
PY 2008
VL 141
IS 1-4
BP 171
EP 184
DI 10.1007/s11214-008-9423-3
PG 14
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 389JP
UT WOS:000262089000008
ER
PT J
AU Angelopoulos, V
Sibeck, D
Carlson, CW
McFadden, JP
Larson, D
Lin, RP
Bonnell, JW
Mozer, FS
Ergun, R
Cully, C
Glassmeier, KH
Auster, U
Roux, A
LeContel, O
Frey, S
Phan, T
Mende, S
Frey, H
Donovan, E
Russell, CT
Strangeway, R
Liu, J
Mann, I
Rae, IJ
Raeder, J
Li, X
Liu, W
Singer, HJ
Sergeev, VA
Apatenkov, S
Parks, G
Fillingim, M
Sigwarth, J
AF Angelopoulos, V.
Sibeck, D.
Carlson, C. W.
McFadden, J. P.
Larson, D.
Lin, R. P.
Bonnell, J. W.
Mozer, F. S.
Ergun, R.
Cully, C.
Glassmeier, K. H.
Auster, U.
Roux, A.
LeContel, O.
Frey, S.
Phan, T.
Mende, S.
Frey, H.
Donovan, E.
Russell, C. T.
Strangeway, R.
Liu, J.
Mann, I.
Rae, I. J.
Raeder, J.
Li, X.
Liu, W.
Singer, H. J.
Sergeev, V. A.
Apatenkov, S.
Parks, G.
Fillingim, M.
Sigwarth, J.
TI First Results from the THEMIS Mission
SO SPACE SCIENCE REVIEWS
LA English
DT Review
DE THEMIS; Magnetosphere; Substorms; Radiation belts; Magnetopause
ID TAIL CURRENT DISRUPTION; SUBSTORM CURRENT WEDGE; DAWN-DUSK ASYMMETRY;
PLASMA SHEET; MODEL; EXPANSION; MAGNETOTAIL; ONSET; MAGNETOSPHERE;
MAGNETOPAUSE
AB THEMIS was launched on February 17, 2007 to determine the trigger and large-scale evolution of substorms. During the first seven months of the mission the five satellites coasted near their injection orbit to avoid differential precession in anticipation of orbit placement, which started in September 2007 and led to a commencement of the baseline mission in December 2007. During the coast phase the probes were put into a string-of-pearls configuration at 100 s of km to 2 R(E) along-track separations, which provided a unique view of the magnetosphere and enabled an unprecedented dataset in anticipation of the first tail season. In this paper we describe the first THEMIS substorm observations, captured during instrument commissioning on March 23, 2007. THEMIS measured the rapid expansion of the plasma sheet at a speed that is commensurate with the simultaneous expansion of the auroras on the ground. These are the first unequivocal observations of the rapid westward expansion process in space and on the ground. Aided by the remote sensing technique at energetic particle boundaries and combined with ancillary measurements and MHD simulations, they allow determination and mapping of space currents. These measurements show the power of the THEMIS instrumentation in the tail and the radiation belts. We also present THEMIS Flux Transfer Events (FTE) observations at the magnetopause, which demonstrate the importance of multi-point observations there and the quality of the THEMIS instrumentation in that region of space.
C1 [Angelopoulos, V.; Russell, C. T.; Strangeway, R.; Liu, J.] Univ Calif Los Angeles, IGPP ESS, Los Angeles, CA 90095 USA.
[Sibeck, D.; Sigwarth, J.] NASA, GSFC, Greenbelt, MD 20771 USA.
[Carlson, C. W.; McFadden, J. P.; Larson, D.; Lin, R. P.; Bonnell, J. W.; Mozer, F. S.; Frey, S.; Phan, T.; Mende, S.; Frey, H.; Parks, G.; Fillingim, M.] Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA.
[Ergun, R.; Li, X.; Liu, W.] Univ Colorado, LASP, Boulder, CO 80303 USA.
[Cully, C.] Swedish Inst Space Phys, SE-75121 Uppsala, Sweden.
[Glassmeier, K. H.; Auster, U.] TUBS, D-38106 Braunschweig, Germany.
[Roux, A.; LeContel, O.] CETP IPSL, F-78140 Velizy Villacoublay, France.
[Donovan, E.] Univ Calgary, Dept Phys & Astron, Calgary, AB T2N 1N4, Canada.
[Mann, I.; Rae, I. J.] Univ Alberta, Dept Phys, Edmonton, AB T6G 2J1, Canada.
[Raeder, J.] Univ New Hampshire, Ctr Space Sci, Durham, NH 03824 USA.
[Singer, H. J.] NOAA, Space Environm Lab, Boulder, CO 80303 USA.
[Sergeev, V. A.; Apatenkov, S.] St Petersburg State Univ, Inst Phys, St Petersburg 198904, Russia.
RP Angelopoulos, V (reprint author), Univ Calif Los Angeles, IGPP ESS, Los Angeles, CA 90095 USA.
EM vassilis@ssl.berkeley.edu
RI Sibeck, David/D-4424-2012; Rae, Jonathan/D-8132-2013; Liu,
Wenlong/G-5585-2013; Apatenkov, Sergey/J-4899-2013; Cully,
Christopher/P-2539-2016; Sergeev, Victor/H-1173-2013;
OI Liu, Wenlong/0000-0001-7991-5067; Sergeev, Victor/0000-0002-4569-9631;
Apatenkov, Sergey/0000-0001-8959-3479; Donovan,
Eric/0000-0002-8557-4155; Frey, Harald/0000-0001-8955-3282; Liu,
Jiang/0000-0002-7489-9384
FU NASA [NAS5-02099]
FX This research was funded by NASA contract NAS5-02099.
NR 40
TC 105
Z9 105
U1 4
U2 26
PU SPRINGER
PI DORDRECHT
PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS
SN 0038-6308
J9 SPACE SCI REV
JI Space Sci. Rev.
PD DEC
PY 2008
VL 141
IS 1-4
BP 453
EP 476
DI 10.1007/s11214-008-9378-4
PG 24
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 389JP
UT WOS:000262089000019
ER
PT J
AU Le Contel, O
Roux, A
Robert, P
Coillot, C
Bouabdellah, A
de la Porte, B
Alison, D
Ruocco, S
Angelopoulos, V
Bromund, K
Chaston, CC
Cully, C
Auster, HU
Glassmeier, KH
Baumjohann, W
Carlson, CW
McFadden, JP
Larson, D
AF Le Contel, O.
Roux, A.
Robert, P.
Coillot, C.
Bouabdellah, A.
de la Porte, B.
Alison, D.
Ruocco, S.
Angelopoulos, V.
Bromund, K.
Chaston, C. C.
Cully, C.
Auster, H. U.
Glassmeier, K. H.
Baumjohann, W.
Carlson, C. W.
McFadden, J. P.
Larson, D.
TI First Results of the THEMIS Search Coil Magnetometers
SO SPACE SCIENCE REVIEWS
LA English
DT Review
DE THEMIS; Solar wind; Shock; Magnetosheath; Flux transfer event;
Magnetopause; Substorm; Search-coil; ULF/ELF magnetic waves
ID MAGNETIC RECONNECTION; SUBSTORM ONSET; CURRENT DISRUPTION; WAVES;
INSTABILITY; IDENTIFICATION; MAGNETOSPHERE; MAGNETOTAIL; TURBULENCE;
SHEET
AB We present the first data from the THEMIS Search Coil Magnetometers (SCM), taken between March and June 2007 while the THEMIS constellation apogee moved from the duskside toward the dawnside. Data reduction, especially the SCM calibration method and spurious noise reduction process, is described. The signatures of magnetic fluctuations in key magnetospheric regions such as the bow shock, the magnetopause and the magnetotail during a substorm, are described. We also discuss the role that magnetic fluctuations could play in plasma transport, acceleration and heating.
C1 [Le Contel, O.; Roux, A.; Robert, P.; Coillot, C.; Bouabdellah, A.; de la Porte, B.; Alison, D.; Ruocco, S.] CETP, F-78140 Velizy Villacoublay, France.
[Angelopoulos, V.] Univ Calif Los Angeles, IGPP, Los Angeles, CA 90095 USA.
[Bromund, K.] NASA, GSFC, Space Weather Lab, SP Syst Inc, Greenbelt, MD USA.
[Chaston, C. C.; Carlson, C. W.; McFadden, J. P.; Larson, D.] Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA.
[Cully, C.] Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80309 USA.
[Auster, H. U.; Glassmeier, K. H.] Tech Univ Carolo Wilhelmina Braunschweig, Inst Geophys & Extraterr Phys, D-38106 Braunschweig, Germany.
[Baumjohann, W.] Austrian Acad Sci, Space Res Inst, A-8010 Graz, Austria.
RP Le Contel, O (reprint author), CETP, 10-12 Ave Europe, F-78140 Velizy Villacoublay, France.
EM olivier.lecontel@cetp.ipsl.fr
RI Baumjohann, Wolfgang/A-1012-2010; Cully, Christopher/P-2539-2016
OI Baumjohann, Wolfgang/0000-0001-6271-0110;
FU THEMIS; CNES; CNRS; NASA [NAS5-02099]; KHG; UA University of
Braunschweig; German Ministerium fur Wirtschaft und Technologie; German
Zentrum fur Luft- und Raumfahrt [50QP0402]
FX We are pleased to acknowledge the friendly collaboration and the help of
other THEMIS team members, in particular, P. Harvey, R. Jackson, J.
Lewis, M. Ludlam, D. Meilhan, H. Richard, and E. Taylor. The French
involvement on THEMIS is supported by CNES and CNRS. Work in the US was
supported by NASA contract NAS5-02099. The work of KHG and UA at the
Technical University of Braunschweig was financially supported by the
German Ministerium fur Wirtschaft und Technologie and the German Zentrum
fur Luft- und Raumfahrt under grant 50QP0402.
NR 33
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U1 4
U2 8
PU SPRINGER
PI DORDRECHT
PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS
SN 0038-6308
EI 1572-9672
J9 SPACE SCI REV
JI Space Sci. Rev.
PD DEC
PY 2008
VL 141
IS 1-4
BP 509
EP 534
DI 10.1007/s11214-008-9371-y
PG 26
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 389JP
UT WOS:000262089000021
ER
PT J
AU Fetzer, EJ
Read, WG
Waliser, D
Kahn, BH
Tian, BJ
Vomel, H
Irion, FW
Su, H
Eldering, A
Juarez, MD
Jiang, J
Dang, V
AF Fetzer, Eric J.
Read, William G.
Waliser, Duane
Kahn, Brian H.
Tian, Baijun
Voemel, Holger
Irion, Fredrick W.
Su, Hui
Eldering, Annmarie
Juarez, Manuel de la Torre
Jiang, Jonathan
Dang, Van
TI Comparison of upper tropospheric water vapor observations from the
Microwave Limb Sounder and Atmospheric Infrared Sounder
SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
LA English
DT Article
ID TROPICAL UPPER TROPOSPHERE; RADIATIVE-TRANSFER MODEL; CLOUD ICE
MEASUREMENTS; EOS MLS; RELATIVE-HUMIDITY; AURA SATELLITE; CLIMATE;
TROPOPAUSE; TRANSPORT; FEEDBACK
AB We compare matched retrievals of upper tropospheric water vapor (UTWV) mixing ratios from the Microwave Limb Sounder (MLS) instrument on the Aura satellite, and the Atmospheric Infrared Sounder (AIRS) instrument on the Aqua satellite. Because each instrument's sampling is affected by tropical conditions, about half of mutually observed scenes in the tropics yield simultaneous successful retrievals from both systems. The fraction of mutually retrieved scenes drops to 30% at higher latitudes where clouds significantly inhibit AIRS sounding. Essentially all scenes observed by MLS in extratropical and polar regions yield successful retrievals. At 250 hPa in the tropics, measurements from the two instruments are highly correlated, the differences of their means ((Delta) over bar (q)) are smaller than 10%, and the standard deviations of their differences (sigma(q)) are 30% or less. At 300 hPa, MLS means are drier by 10-15%, and sigma(q) is 40-60%, indicating that responses of MLS and AIRS to UTWV perturbations are not one-to-one. Root mean square agreement is also poorer over the poles at 300 hPa and at 200 and 150 hPa at lower latitudes. In these regions, vertical bar(Delta) over bar (q)vertical bar = 10% or more, and sigma(q) = 40-70%. Correlations between the two data sets are 0.7-0.9 at 300 and 250 hPa globally and at 200 hPa in the tropics. This high correlation indicates that sigma(q) of 50% or greater comes mainly from systematic differences in sensitivity of the two instruments, especially for small and large UTWV amounts; larger values of sigma(q) are generally not due to large random errors from either instrument. An AIRS low-end sensitivity threshold of 15-20 ppmv leads to poorer agreement under the driest conditions. Disagreement at 300 hPa likely comes from overestimation by MLS for the wettest conditions of > 400 ppmv. While MLS is biased slightly dry overall at 300 hPa, it is biased wet in the wettest regions, particularly those associated with deep convection. These sensitivity differences explain nonunity slopes of linear fits to the two data sets. MLS everywhere has a greater dynamic range than AIRS, with larger maxima and smaller minima. Good agreement at 250 hPa suggests AIRS uncertainties of 25% up to the reported 250-200 hPa layer in the tropics and extratropics, consistent with previous comparisons with balloon- and aircraft-borne instruments. The agreement at 250 hPa also indicates that MLS is reliable from its reported 215-hPa level upward in altitude.
C1 [Fetzer, Eric J.; Read, William G.; Waliser, Duane; Kahn, Brian H.; Tian, Baijun; Irion, Fredrick W.; Su, Hui; Eldering, Annmarie; Juarez, Manuel de la Torre; Jiang, Jonathan; Dang, Van] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[Voemel, Holger] Deutsch Wetterdienst, D-15848 Tauche Lindenberg, Germany.
[Tian, Baijun] Univ Calif Los Angeles, Joint Inst Reg Earth Syst Sci & Engn, Los Angeles, CA USA.
RP Fetzer, EJ (reprint author), CALTECH, Jet Prop Lab, MS 169-237,4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM eric.j.fetzer@jpl.nasa.gov
RI Tian, Baijun/A-1141-2007
OI Tian, Baijun/0000-0001-9369-2373
FU Jet Propulsion Laboratory; California Institute of Technology; National
Aeronautics and Space Administration; AIRS; MLS; NASA; Energy and
Water-cycle Study (NEWS)
FX The research described in this paper was carried out at the Jet
Propulsion Laboratory, California Institute of Technology, under a
contract with the National Aeronautics and Space Administration. It was
supported by the AIRS and MLS projects at JPL and by the NASA and Energy
and Water-cycle Study (NEWS) project. We benefited from conversations
with Darryn Waugh, Andrew Gettelman, Jim Yoe, M. K. Rama Varma Raja,
Bill Randel, Mijeong Park, George Aumann, and Evan Fishbein.
NR 75
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U1 0
U2 8
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 2169-897X
EI 2169-8996
J9 J GEOPHYS RES-ATMOS
JI J. Geophys. Res.-Atmos.
PD NOV 29
PY 2008
VL 113
IS D22
AR D22110
DI 10.1029/2008JD010000
PG 17
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 377IN
UT WOS:000261245000002
ER
PT J
AU Pan, XJ
Mannino, A
Russ, ME
Hooker, SB
AF Pan, Xiaoju
Mannino, Antonio
Russ, Mary E.
Hooker, Stanford B.
TI Remote sensing of the absorption coefficients and chlorophyll a
concentration in the United States southern Middle Atlantic Bight from
SeaWiFS and MODIS-Aqua
SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
LA English
DT Article
ID DISSOLVED ORGANIC-MATTER; CHESAPEAKE-BAY; OCEAN COLOR; PRIMARY
PRODUCTIVITY; PHYTOPLANKTON ASSEMBLAGES; LIGHT-ABSORPTION; COASTAL
WATERS; SARGASSO SEA; PARTICLES; PIGMENTS
AB At present, satellite remote sensing of coastal water quality and constituent concentration is subject to large errors as compared to the capability of satellite sensors in oceanic waters. In this study, field measurements collected on a series of cruises within United States southern Middle Atlantic Bight (SMAB) were applied to improve retrievals of satellite ocean color products from the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) and the Moderate Resolution Imaging Spectrometer (MODIS-Aqua) in order to examine the factors that regulate the bio-optical properties within the continental shelf waters of the SMAB. The first objective was to develop improvements in satellite retrievals of absorption coefficients of phytoplankton (a(ph)), colored dissolved organic matter (CDOM) (a(g)), nonpigmented particles (ad), nonpigmented particles plus CDOM (a(dg)), and chlorophyll a concentration ([Chl_a]). Several algorithms were compared to derive constituent absorption coefficients from remote sensing reflectance (R(rs)) ratios. The validation match-ups showed that the mean absolute percent differences were typically <35%, although higher errors were found for ad retrievals. Seasonal and spatial variability of satellite-derived absorption coefficients and [Chl_a] was apparent and consistent with field data. CDOM is a major contributor to the bio-optical properties of the SMAB, accounting for 35-70% of total light absorption by particles plus CDOM at 443 nm, as compared to 30-45% for phytoplankton and 0-20% for nonpigmented particles. The overestimation of [Chl_a] from the operational satellite algorithms may be attributed to the strong CDOM absorption in this region. River discharge is important in controlling the bio-optical environment but cannot explain all of the regional and seasonal variability of biogeochemical constituents in the SMAB.
C1 [Pan, Xiaoju; Mannino, Antonio; Russ, Mary E.; Hooker, Stanford B.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
[Russ, Mary E.] Univ Maryland, Goddard Earth Sci & Technol Ctr, Catonsville, MD 21228 USA.
RP Pan, XJ (reprint author), NASA, Goddard Space Flight Ctr, Mail Code 614-7,Bldg 22,Room 248, Greenbelt, MD 20771 USA.
EM xpan@neptune-web.gsfc.nasa.gov
RI Hooker, Stanford/E-2162-2012; Mannino, Antonio/I-3633-2014
FU NASA Postdoctoral Program at the Goddard Space Flight Center; Oak Ridge
Associated Universities; NASA New Investigator Program,; Coastal
Observatories program [NA03NOS4730220]
FX This research was supported by an appointment to the NASA Postdoctoral
Program at the Goddard Space Flight Center, administered by Oak Ridge
Associated Universities through a contract with NASA. This work was
funded with support from the NASA New Investigator Program,
Interdisciplinary Science, and Earth Observing System programs and by
NOAA through a grant in support of the Coastal Observatories program
(NA03NOS4730220). We thank the captains and crews of R/V Cape Henlopen,
R/V Hugh R. Sharp, and R/V Fay Slover. H. Throckmorton, P. Bernhardt, K.
C. Filippino, C. Makinen, and M. Linksweiler provided assistance in
collecting particulate samples. We are grateful to J. Morrow, J. Brown,
D. D'Alimonte, and J.-N. Druon for deploying the profiling radiometer;
to L. Van Heukelem and C. Thomas for analyzing HPLC pigments; and the
Ocean Biology Processing Group at GSFC. J. O'Reilly kindly provided the
high-resolution bathymetry data.
NR 58
TC 23
Z9 23
U1 0
U2 10
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0148-0227
J9 J GEOPHYS RES-OCEANS
JI J. Geophys. Res.-Oceans
PD NOV 29
PY 2008
VL 113
IS C11
AR C11022
DI 10.1029/2008JC004852
PG 15
WC Oceanography
SC Oceanography
GA 377IT
UT WOS:000261245600003
ER
PT J
AU Abdo, AA
Allen, B
Aune, T
Berley, D
Blaufuss, E
Casanova, S
Chen, C
Dingus, BL
Ellsworth, RW
Fleysher, L
Fleysher, R
Gonzalez, MM
Goodman, JA
Hoffman, CM
Huntemeyer, PH
Kolterman, BE
Lansdell, CP
Linnemann, JT
McEnery, JE
Mincer, AI
Nemethy, P
Noyes, D
Pretz, J
Ryan, JM
Parkinson, PMS
Shoup, A
Sinnis, G
Smith, AJ
Sullivan, GW
Vasileiou, V
Walker, GP
Williams, DA
Yodh, GB
AF Abdo, A. A.
Allen, B.
Aune, T.
Berley, D.
Blaufuss, E.
Casanova, S.
Chen, C.
Dingus, B. L.
Ellsworth, R. W.
Fleysher, L.
Fleysher, R.
Gonzalez, M. M.
Goodman, J. A.
Hoffman, C. M.
Huentemeyer, P. H.
Kolterman, B. E.
Lansdell, C. P.
Linnemann, J. T.
McEnery, J. E.
Mincer, A. I.
Nemethy, P.
Noyes, D.
Pretz, J.
Ryan, J. M.
Parkinson, P. M. Saz
Shoup, A.
Sinnis, G.
Smith, A. J.
Sullivan, G. W.
Vasileiou, V.
Walker, G. P.
Williams, D. A.
Yodh, G. B.
TI Discovery of Localized Regions of Excess 10-TeV Cosmic Rays
SO PHYSICAL REVIEW LETTERS
LA English
DT Article
ID ANISOTROPY
AB The 7 year data set of the Milagro TeV observatory contains 2.2x10(11) events of which most are due to hadronic cosmic rays. These data are searched for evidence of intermediate scale structure. Excess emission on angular scales of similar to 10 degrees has been found in two localized regions of unknown origin with greater than 12 sigma significance. Both regions are inconsistent with pure gamma-ray emission with high confidence. One of the regions has a different energy spectrum than the isotropic cosmic-ray flux at a level of 4.6 sigma, and it is consistent with hard spectrum protons with an exponential cutoff, with the most significant excess at similar to 10 TeV. Potential causes of these excesses are explored, but no compelling explanations are found.
C1 [Abdo, A. A.] USN, Res Lab, Washington, DC 20375 USA.
[Allen, B.] Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA.
[Aune, T.; Parkinson, P. M. Saz; Williams, D. A.] Univ Calif Santa Cruz, Santa Cruz, CA 95064 USA.
[Berley, D.; Blaufuss, E.; Goodman, J. A.; Noyes, D.; Smith, A. J.; Sullivan, G. W.; Vasileiou, V.] Univ Maryland, College Pk, MD 20742 USA.
[Casanova, S.] Max Planck Inst Kernphys, D-69117 Heidelberg, Germany.
[Chen, C.; Yodh, G. B.] Univ Calif Irvine, Irvine, CA USA.
[Dingus, B. L.; Hoffman, C. M.; Huentemeyer, P. H.; Pretz, J.; Sinnis, G.] Los Alamos Natl Lab, Los Alamos, NM USA.
[Ellsworth, R. W.] George Mason Univ, Fairfax, VA 22030 USA.
[Fleysher, L.; Fleysher, R.; Kolterman, B. E.; Mincer, A. I.; Nemethy, P.] NYU, New York, NY USA.
[Gonzalez, M. M.] Univ Nacl Autonoma Mexico, Inst Astron, Mexico City 04510, DF, Mexico.
[Lansdell, C. P.] Inst Def Analyses, Alexandria, VA USA.
[Linnemann, J. T.] Michigan State Univ, E Lansing, MI 48824 USA.
[McEnery, J. E.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
[Ryan, J. M.] Univ New Hampshire, Durham, NH 03824 USA.
[Shoup, A.] Ohio State Univ, Lima, OH 45804 USA.
[Walker, G. P.] Natl Secur Technol, Las Vegas, NV USA.
RP Abdo, AA (reprint author), USN, Res Lab, Washington, DC 20375 USA.
RI McEnery, Julie/D-6612-2012; Casanova, Sabrina/J-8935-2013;
OI Casanova, Sabrina/0000-0002-6144-9122; Mincer,
Allen/0000-0002-6307-1418; Dingus, Brenda/0000-0001-8451-7450; Allen,
Bruce/0000-0003-4285-6256
FU National Science Foundation [PHY-0245234, -0302000, -0400424, -0504201,
-0601080, ATM-0002744]; U. S. Department of Energy; Los Alamos National
Laboratory; University of California; Institute of Geophysics and
Planetary Physics
FX We gratefully acknowledge Scott Delay and Michael Schneider for their
dedicated efforts in the construction and maintenance of the Milagro
experiment. This work has been supported by the National Science
Foundation (under Grants PHY-0245234, -0302000, -0400424, -0504201,
-0601080, and ATM-0002744), the U. S. Department of Energy (Office of
High-Energy Physics and Office of Nuclear Physics), Los Alamos National
Laboratory, the University of California, and the Institute of
Geophysics and Planetary Physics.
NR 13
TC 105
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U1 0
U2 1
PU AMER PHYSICAL SOC
PI COLLEGE PK
PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA
SN 0031-9007
J9 PHYS REV LETT
JI Phys. Rev. Lett.
PD NOV 28
PY 2008
VL 101
IS 22
AR 221101
DI 10.1103/PhysRevLett.101.221101
PG 5
WC Physics, Multidisciplinary
SC Physics
GA 376WT
UT WOS:000261214400009
PM 19113471
ER
PT J
AU Garvin, JB
AF Garvin, James. B.
TI The Price of Exploration
SO SCIENCE
LA English
DT Letter
C1 [Garvin, James. B.] NASA, Goddard Space Flight Ctr, Sci & Explorat Directorate, Greenbelt, MD 20771 USA.
RP Garvin, JB (reprint author), NASA, Goddard Space Flight Ctr, Sci & Explorat Directorate, Greenbelt, MD 20771 USA.
EM james.b.garvin@nasa.gov
NR 0
TC 0
Z9 0
U1 0
U2 0
PU AMER ASSOC ADVANCEMENT SCIENCE
PI WASHINGTON
PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA
SN 0036-8075
J9 SCIENCE
JI Science
PD NOV 28
PY 2008
VL 322
IS 5906
BP 1324
EP 1324
PG 1
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA 376FX
UT WOS:000261170600010
PM 19039117
ER
PT J
AU Marley, MS
AF Marley, Mark S.
TI ASTRONOMY Exoplanets-Seeing Is Believing
SO SCIENCE
LA English
DT Editorial Material
ID BROWN DWARF; GIANT PLANETS
C1 [Marley, Mark S.] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
RP Marley, MS (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
EM mark.s.marley@nasa.gov
RI Marley, Mark/I-4704-2013
NR 11
TC 0
Z9 0
U1 0
U2 1
PU AMER ASSOC ADVANCEMENT SCIENCE
PI WASHINGTON
PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA
SN 0036-8075
J9 SCIENCE
JI Science
PD NOV 28
PY 2008
VL 322
IS 5906
BP 1335
EP 1337
DI 10.1126/science.1167569
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA 376FX
UT WOS:000261170600024
PM 19008413
ER
PT J
AU Kalas, P
Graham, JR
Chiang, E
Fitzgerald, MP
Clampin, M
Kite, ES
Stapelfeldt, K
Marois, C
Krist, J
AF Kalas, Paul
Graham, James R.
Chiang, Eugene
Fitzgerald, Michael P.
Clampin, Mark
Kite, Edwin S.
Stapelfeldt, Karl
Marois, Christian
Krist, John
TI Optical Images of an Exosolar Planet 25 Light-Years from Earth
SO SCIENCE
LA English
DT Article
ID FOMALHAUT; SPECTRA; DEBRIS; PROFILES; COLORS; DISKS; MODEL
AB Fomalhaut, a bright star 7.7 parsecs ( 25 light- years) from Earth, harbors a belt of cold dust with a structure consistent with gravitational sculpting by an orbiting planet. Here, we present optical observations of an exoplanet candidate, Fomalhaut b. Fomalhaut b lies about 119 astronomical units ( AU) from the star and 18 AU of the dust belt, matching predictions of its location. Hubble Space Telescope observations separated by 1.73 years reveal counterclockwise orbital motion. Dynamical models of the interaction between the planet and the belt indicate that the planet's mass is at most three times that of Jupiter; a higher mass would lead to gravitational disruption of the belt, matching predictions of its location. The flux detected at 0.8 mm is also consistent with that of a planet with mass no greater than a few times that of Jupiter. The brightness at 0.6 mm and the lack of detection at longer wavelengths suggest that the detected flux may include starlight reflected off a circumplanetary disk, with dimension comparable to the orbits of the Galilean satellites. We also observe variability of unknown origin at 0.6 mm.
C1 [Kalas, Paul; Graham, James R.; Chiang, Eugene] Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA.
[Chiang, Eugene; Kite, Edwin S.] Univ Calif Berkeley, Dept Earth & Planetary Sci, Berkeley, CA 94720 USA.
[Fitzgerald, Michael P.] Lawrence Livermore Natl Lab, Inst Geophys & Planetary Sci, Livermore, CA 94551 USA.
[Clampin, Mark] NASA, Goddard Space Flight Ctr, Exoplanets & Stellar Astrophys Lab, Greenbelt, MD 20771 USA.
[Stapelfeldt, Karl; Krist, John] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[Marois, Christian] Herzberg Inst Astrophys, Victoria, BC V9E 2E7, Canada.
RP Kalas, P (reprint author), Univ Calif Berkeley, Dept Astron, 601 Campbell Hall, Berkeley, CA 94720 USA.
EM kalas@astron.berkeley.edu
RI Fitzgerald, Michael/C-2642-2009; Clampin, mark/D-2738-2012; Stapelfeldt,
Karl/D-2721-2012
OI Fitzgerald, Michael/0000-0002-0176-8973;
FU HST programs [GO-10598, GO- 10539]; NASA [NAS5-26555, AST-0507805];
Space Telescope Science Institute; Michelson Fellowship Program;
Berkeley Fellowship; U.S. Department of Energy [DE-AC52- 07NA27344]
FX Supported by HST programs GO-10598 (P.K.) and GO-10539 (K.S. and J.K.),
provided by NASA through a grant from the Space Telescope Science
Institute (STScI) under NASA contract NAS5-26555; NSF grant AST-0507805
( E. C.); the Michelson Fellowship Program, under contract with JPL,
funded by NASA ( M. P. F.); and a Berkeley Fellowship (E.S. K.). Work at
LLNL was performed under the auspices of the U.S. Department of Energy
under contract DE-AC52- 07NA27344. We thank the staff at STScI, Keck,
and Gemini for supporting our observations.
NR 21
TC 562
Z9 563
U1 3
U2 30
PU AMER ASSOC ADVANCEMENT SCIENCE
PI WASHINGTON
PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA
SN 0036-8075
J9 SCIENCE
JI Science
PD NOV 28
PY 2008
VL 322
IS 5906
BP 1345
EP 1348
DI 10.1126/science.1166609
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA 376FX
UT WOS:000261170600029
PM 19008414
ER
PT J
AU Remsberg, EE
AF Remsberg, E. E.
TI On the response of Halogen Occultation Experiment (HALOE) stratospheric
ozone and temperature to the 11-year solar cycle forcing
SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
LA English
DT Article
ID QUASI-BIENNIAL OSCILLATION; MIDDLE ATMOSPHERE; LONG-TERM; INTERANNUAL
VARIABILITY; SATELLITE DATA; MODEL; AEROSOL; TREND; CONSTITUENTS;
MIDLATITUDES
AB Results are presented on responses in 14-year (1991-2005) time series of stratospheric ozone and temperature from the Halogen Occultation Experiment (HALOE) of the Upper Atmosphere Research Satellite (UARS) to a solar cycle (SC-like) variation. The ozone time series are for ten, 20-degree-wide, latitude bins from 45 degrees S to 45 degrees N and for thirteen "half-Umkehr'' layers of about 2.5 km thickness and extending from 63 hPa to 0.7 hPa. The temperature time series analyses were restricted to pressure levels in the range of 2 hPa to 0.7 hPa. Multiple linear regression ( MLR) techniques were applied to each of the 130 time series of bin-averaged, sunrise plus sunset ozone points over that latitude/pressure domain. A simple, 11-year periodic term and a linear trend term were added to the final MLR models after their seasonal and interannual terms had been determined. Where the amplitudes of the 11-year terms are significant, they are in phase with those of the more standard proxies for the solar UV flux. The maximum minus minimum response for ozone is on the order of 2 to 3% from about 2 to 5 hPa and for the latitudes of 45 degrees S to 45 degrees N. There is also a significant maximum minus minimum response on the order of 1 K for temperature between 15 degrees S and 15 degrees N and from 2 to 0.7 hPa. The associated linear trends for ozone are near zero in the upper stratosphere. It is noted, however, that effects of the changes in total chlorine during this 14-year period were not accounted for explicitly and that their omission can be a confounding effect for both the analyzed solar cycle responses and the linear terms, especially for tropical upper stratospheric ozone. It is concluded that the solar occultation technique of HALOE provided adequate sampling and sufficient vertical resolution for obtaining the solar cycle response in stratospheric ozone.
C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA.
RP Remsberg, EE (reprint author), NASA, Langley Res Ctr, Mail Stop 401B, Hampton, VA 23681 USA.
EM Ellis.E.Remsberg@nasa.gov
FU UARS Program Office at NASA Headquarters; UARS Project Office at
NASA/GSFC
FX The author embarked on this analysis as a result of his invitation to
participate in a Workshop hosted by Kunihiko Kodera at the 2004 Fall AGU
Meeting. The author appreciates discussions about this work that he has
had with two colleagues: Murali Natarajan, concerning comparisons of the
findings with published results from model studies, and Gretchen
Lingenfelser concerning the MLR analyses. Special thanks go to Jim
Russell, HALOE Principal Investigator, and Larry Gordley and colleagues
of GATS, Inc., for producing the high-quality HALOE data set. He also
appreciates the detailed comments of the three anonymous reviewers.
Support for this work was provided by the UARS Program Office at NASA
Headquarters and the UARS Project Office at NASA/GSFC.
NR 70
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U1 0
U2 6
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 2169-897X
J9 J GEOPHYS RES-ATMOS
JI J. Geophys. Res.-Atmos.
PD NOV 27
PY 2008
VL 113
AR D22304
DI 10.1029/2008JD010189
PG 15
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 377IM
UT WOS:000261244900010
ER
PT J
AU Au, M
Jurgensen, AR
Spencer, WA
Anton, DL
Pinkerton, FE
Hwang, SJ
Kim, C
Bowman, RC
AF Au, Ming
Jurgensen, Arthur R.
Spencer, William A.
Anton, Donald L.
Pinkerton, Frederick E.
Hwang, Son-Jong
Kim, Chul
Bowman, Robert C., Jr.
TI Stability and Reversibility of Lithium Borohydrides Doped by Metal
Halides and Hydrides
SO JOURNAL OF PHYSICAL CHEMISTRY C
LA English
DT Article
ID HYDROGEN STORAGE; LIBH4; DESORPTION; NMR
AB In an effort to develop reversible metal borohydrides with high hydrogen storage capacities and low dehydriding temperature, doping LiBH(4) with various metal halides and hydrides has been conducted. Several metal halides such as TiCl(3), TiF(3), and ZnF(2) effectively reduced the dehydriding temperature through a cation exchange interaction. Some of the halide doped LiBH(4) are partially reversible. The LiBH(4) + 0.1TiF(3) desorbed 3.5 wt % and 8.5 wt % hydrogen at 150 and 450 degrees C, respectively, with subsequent reabsorption of 6 wt % hydrogen at 500 degrees C and 70 bar observed. XRD and NMR analysis of the rehydrided samples confirmed the reformation of LiBH(4). The existence of the (B(12)H(12))(-2) species in dehydrided and rehydrided samples gives insight into the resultant partial reversibility. A number of other halides, MgF(2), MgCl(2), CaCl(2), SrCl(2), and FeCl(3), did not reduce the dehydriding temperature of LiBH4 significantly. XRD and TGA-RGA analyses indicated that an increasing proportion of halides such as TiCl(3), TiF(3), and ZnCl(2) from 0.1 to 0.5 mol makes lithium borohydrides less stable and volatile. Although the less stable borohydrides such as LiBH(4) + 0.5TiCl(3), LiBH(4) + 0.5TiF(3), and LiBH(4) + 0.5ZnCl(2) release hydrogen at room temperature, they are not reversible due to unrecoverable boron loss caused by diborane emission. In most cases, doping that produced less stable borohydrides also reduced the reversible hydrogen uptake. It was also observed that halide doping changed the melting points and reduced air sensitivity of lithium borohydrides.
C1 [Au, Ming; Jurgensen, Arthur R.; Spencer, William A.; Anton, Donald L.] Savannah River Natl Lab, Aiken, SC USA.
[Pinkerton, Frederick E.] Gen Motors R&D Ctr, Warren, MI USA.
[Hwang, Son-Jong; Kim, Chul] CALTECH, Div Chem & Chem Engn, Pasadena, CA 91125 USA.
[Bowman, Robert C., Jr.] CALTECH, Jet Prop Lab, Pasadena, CA USA.
RP Au, M (reprint author), Savannah River Natl Lab, Aiken, SC USA.
OI Bowman, Robert/0000-0002-2114-1713
FU General Motors Corporation; DOE [DE-AI-01-05EE11105]; National Science
Foundation (NSF) [9724240, DMR-0520565]
FX This project is financially supported by General Motors Corporation. The
authors also thank Dr. Scott Jorgensen for constructive discussions and
suggestions on the research. Savannah River National Laboratory is
operated by Savannah River Nuclear Solution for the U.S. Department of
Energy under contract DE-AC09-08SR22470. This research was partially
performed at the Jet Propulsion Laboratory, which is operated by the
California Institute of Technology under contract with the NASA. This
work was also partially supported by DOE through Award Number
DE-AI-01-05EE11105. The NMR facility at Caltech was supported by the
National Science Foundation (NSF) under Grant Number 9724240 and
partially supported by the MRSEC Program of the NSF under Award Number
DMR-0520565.
NR 32
TC 87
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U1 5
U2 30
PU AMER CHEMICAL SOC
PI WASHINGTON
PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA
SN 1932-7447
J9 J PHYS CHEM C
JI J. Phys. Chem. C
PD NOV 27
PY 2008
VL 112
IS 47
BP 18661
EP 18671
DI 10.1021/jp8024304
PG 11
WC Chemistry, Physical; Nanoscience & Nanotechnology; Materials Science,
Multidisciplinary
SC Chemistry; Science & Technology - Other Topics; Materials Science
GA 374PP
UT WOS:000261056500055
ER
PT J
AU Hansen, CJ
Esposito, LW
Stewart, AIF
Meinke, B
Wallis, B
Colwell, JE
Hendrix, AR
Larsen, K
Pryor, W
Tian, F
AF Hansen, C. J.
Esposito, L. W.
Stewart, A. I. F.
Meinke, B.
Wallis, B.
Colwell, J. E.
Hendrix, A. R.
Larsen, K.
Pryor, W.
Tian, F.
TI Water vapour jets inside the plume of gas leaving Enceladus
SO NATURE
LA English
DT Article
ID CASSINI; RING; SPECTROSCOPY; FRACTURES; DUST
AB A plume of water vapour escapes from fissures crossing the south polar region of the Saturnian moon Enceladus(1-6). Tidal deformation of a thin surface crust above an internal ocean could result in tensile and compressive stresses that would affect the width of the fissures(7); therefore, the quantity of water vapour released at different locations in Enceladus' eccentric orbit is a crucial measurement of tidal control of venting. Here we report observations of an occultation of a star by the plume on 24 October 2007 that revealed four high- density gas jets superimposed on the background plume. The gas jet positions coincide with those of dust jets reported elsewhere(8) inside the plume. The maximum water column density in the plume is about twice the density reported earlier(2). The density ratio does not agree with predictions(7)-we should have seen less water than was observed in 2005. The ratio of the jets' bulk vertical velocities to their thermal velocities is 1.5 +/- 0.2, which supports the hypothesis that the source of the plume is liquid water, with gas accelerated to supersonic velocity in nozzle- like channels(9).
C1 [Hansen, C. J.; Wallis, B.; Hendrix, A. R.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[Esposito, L. W.; Stewart, A. I. F.; Meinke, B.; Larsen, K.] Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80303 USA.
[Colwell, J. E.] Univ Cent Florida, Planetary Sci Grp, Orlando, FL 32816 USA.
[Pryor, W.] Cent Arizona Coll, Dept Sci, Coolidge, AZ 85228 USA.
[Tian, F.] MIT, Dept Earth Atmospher & Planetary Sci, Cambridge, MA 02139 USA.
RP Hansen, CJ (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM candice.j.hansen@jpl.nasa.gov
RI Tian, Feng/C-1344-2015
OI Tian, Feng/0000-0002-9607-560X
FU Cassini Project at the Jet Propulsion Laboratory; California Institute
of Technology; National Aeronautics and Space Administration
FX We acknowledge the Cassini Navigation Team, particularly B. Buffington
and Y. Hahn, whowere central to the success of this observation. This
work was supported by the Cassini Project at the Jet Propulsion
Laboratory, California Institute of Technology, under a contract with
the National Aeronautics and Space Administration.
NR 18
TC 68
Z9 68
U1 2
U2 17
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
J9 NATURE
JI Nature
PD NOV 27
PY 2008
VL 456
IS 7221
BP 477
EP 479
DI 10.1038/nature07542
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA 376FW
UT WOS:000261170500032
PM 19037310
ER
PT J
AU Patra, PK
Law, RM
Peters, W
Roedenbeck, C
Takigawa, M
Aulagnier, C
Baker, I
Bergmann, DJ
Bousquet, P
Brandt, J
Bruhwiler, L
Cameron-Smith, PJ
Christensen, JH
Delage, F
Denning, AS
Fan, S
Geels, C
Houweling, S
Imasu, R
Karstens, U
Kawa, SR
Kleist, J
Krol, MC
Lin, SJ
Lokupitiya, R
Maki, T
Maksyutov, S
Niwa, Y
Onishi, R
Parazoo, N
Pieterse, G
Rivier, L
Satoh, M
Serrar, S
Taguchi, S
Vautard, R
Vermeulen, AT
Zhu, Z
AF Patra, P. K.
Law, R. M.
Peters, W.
Roedenbeck, C.
Takigawa, M.
Aulagnier, C.
Baker, I.
Bergmann, D. J.
Bousquet, P.
Brandt, J.
Bruhwiler, L.
Cameron-Smith, P. J.
Christensen, J. H.
Delage, F.
Denning, A. S.
Fan, S.
Geels, C.
Houweling, S.
Imasu, R.
Karstens, U.
Kawa, S. R.
Kleist, J.
Krol, M. C.
Lin, S. -J.
Lokupitiya, R.
Maki, T.
Maksyutov, S.
Niwa, Y.
Onishi, R.
Parazoo, N.
Pieterse, G.
Rivier, L.
Satoh, M.
Serrar, S.
Taguchi, S.
Vautard, R.
Vermeulen, A. T.
Zhu, Z.
TI TransCom model simulations of hourly atmospheric CO2: Analysis of
synoptic-scale variations for the period 2002-2003
SO GLOBAL BIOGEOCHEMICAL CYCLES
LA English
DT Article
ID CARBON-DIOXIDE; TRANSPORT MODELS; TALL TOWER; INVERSIONS; SINKS;
VARIABILITY; DELTA-C-13; EUROPE; TRENDS; CYCLE
AB The ability to reliably estimate CO2 fluxes from current in situ atmospheric CO2 measurements and future satellite CO2 measurements is dependent on transport model performance at synoptic and shorter timescales. The TransCom continuous experiment was designed to evaluate the performance of forward transport model simulations at hourly, daily, and synoptic timescales, and we focus on the latter two in this paper. Twenty-five transport models or model variants submitted hourly time series of nine predetermined tracers (seven for CO2) at 280 locations. We extracted synoptic-scale variability from daily averaged CO2 time series using a digital filter and analyzed the results by comparing them to atmospheric measurements at 35 locations. The correlations between modeled and observed synoptic CO2 variabilities were almost always largest with zero time lag and statistically significant for most models and most locations. Generally, the model results using diurnally varying land fluxes were closer to the observations compared to those obtained using monthly mean or daily average fluxes, and winter was often better simulated than summer. Model results at higher spatial resolution compared better with observations, mostly because these models were able to sample closer to the measurement site location. The amplitude and correlation of model-data variability is strongly model and season dependent. Overall similarity in modeled synoptic CO2 variability suggests that the first-order transport mechanisms are fairly well parameterized in the models, and no clear distinction was found between the meteorological analyses in capturing the synoptic-scale dynamics.
C1 [Patra, P. K.; Takigawa, M.; Maksyutov, S.; Satoh, M.] JAMSTEC, Frontier Res Ctr Global Change, Yokohama, Kanagawa, Japan.
[Law, R. M.] CSIRO, Marine & Atmospher Res, Aspendale, Vic, Australia.
[Peters, W.; Bruhwiler, L.] NOAA, Earth Syst Res Lab, Boulder, CO USA.
[Peters, W.; Krol, M. C.] Univ Wageningen & Res Ctr, Dept Meteorol & Air Qual, Wageningen, Netherlands.
[Roedenbeck, C.; Karstens, U.] Max Planck Inst Biogeochem, Jena, Germany.
[Aulagnier, C.; Bousquet, P.; Delage, F.; Rivier, L.; Vautard, R.] UVSQ, CNRS, CEA Saclay, Lab Sci Climat & Environm,IPSL, F-91191 Gif Sur Yvette, France.
[Baker, I.; Denning, A. S.; Lokupitiya, R.; Parazoo, N.] Colorado State Univ, Dept Atmospher Sci, Ft Collins, CO 80523 USA.
[Bergmann, D. J.; Cameron-Smith, P. J.] Lawrence Livermore Natl Lab, Livermore, CA USA.
[Brandt, J.; Christensen, J. H.; Geels, C.] Univ Aarhus, Dept Atmospher Environm, Natl Environm Res Inst, Roskilde, Denmark.
[Fan, S.; Lin, S. -J.] NOAA, Geophys Fluid Dynam Lab, Princeton, NJ USA.
[Houweling, S.; Pieterse, G.] Inst Marine & Atmospher Res, Utrecht, Netherlands.
[Houweling, S.; Krol, M. C.] Univ Utrecht, Netherlands Inst Space Res, Utrecht, Netherlands.
[Imasu, R.; Niwa, Y.; Satoh, M.] Univ Tokyo, Ctr Climate Syst Res, Chiba, Japan.
[Karstens, U.] Max Planck Inst Meteorol, Hamburg, Germany.
[Kawa, S. R.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
[Kleist, J.] Privacy Networks, Ft Collins, CO USA.
[Maki, T.] Japan Meteorol Agcy, Div Atmospher Environm, Tokyo, Japan.
[Maksyutov, S.] Natl Inst Environm Studies, Ctr Global Environm Res, Tsukuba, Ibaraki, Japan.
[Onishi, R.] JAMSTEC, Earth Simulator Ctr, Yokohama, Kanagawa, Japan.
[Pieterse, G.; Vermeulen, A. T.] Energy Res Ctr Netherlands, Petten, Netherlands.
[Serrar, S.] European Ctr Medium Range Weather Forecasts, Reading RG2 9AX, Berks, England.
[Taguchi, S.] Natl Inst Adv Ind Sci & Technol, Tsukuba, Ibaraki, Japan.
[Zhu, Z.] Sci Syst & Applicat Inc, Lanham, MD USA.
RP Patra, PK (reprint author), JAMSTEC, Frontier Res Ctr Global Change, Yokohama, Kanagawa, Japan.
RI Takigawa, Masayuki/M-2095-2014; Vermeulen, Alex/A-2867-2015; Maksyutov,
Shamil/G-6494-2011; Karstens, Ute/P-7075-2014; Satoh,
Masaki/G-3325-2015; Patra, Prabir/B-5206-2009; Krol,
Maarten/E-3414-2013; onishi, ryo/D-1109-2014; Peters,
Wouter/B-8305-2008; Krol, Maarten/B-3597-2010; Bergmann,
Daniel/F-9801-2011; Law, Rachel/A-1969-2012; Christensen, Jesper
/E-9524-2011; Kawa, Stephan/E-9040-2012; Brandt, Jorgen/B-3733-2011;
Cameron-Smith, Philip/E-2468-2011; Denning, Scott/F-4974-2011; Geels,
Camilla/G-4757-2013
OI Takigawa, Masayuki/0000-0002-5666-6026; Vermeulen,
Alex/0000-0002-8158-8787; Maksyutov, Shamil/0000-0002-1200-9577;
Karstens, Ute/0000-0002-8985-7742; Satoh, Masaki/0000-0003-3580-8897;
Patra, Prabir/0000-0001-5700-9389; onishi, ryo/0000-0001-9250-0712;
Peters, Wouter/0000-0001-8166-2070; Bergmann,
Daniel/0000-0003-4357-6301; Law, Rachel/0000-0002-7346-0927;
Christensen, Jesper /0000-0002-6741-5839; Cameron-Smith,
Philip/0000-0002-8802-8627; Denning, Scott/0000-0003-3032-7875; Geels,
Camilla/0000-0003-2549-1750
FU CarboEurope; INSU; CEA; IPEV; Australian Greenhouse Office; European
Commission; Laboratory Directed Research and Development Program
[06-ERD-031]; EU [SIP4-CT-2004-516099]; French Environment and Energy
Management Agency (ADEME); French Atomic Energy Commission (CEA);
Ministry of Education, Science, Sports and Culture, Japan
[2005/17GS0203]; FRCGC
FX Maintaining continuous CO2 observation records requires
dedicated principal investigators, research teams and support staff. We
wish to thank those who made their data available for this study.
CO2 measurements at many of the European locations including
Hegyhatsal are sponsored by the CarboEurope project. Mace Head and
Amsterdam Island CO2 data is part of the ORE-RAMCES
monitoring network coordinated by LSCE/IPSL and supported by INSU, CEA
and IPEV. An experiment such as this generates a large model data set.
Many thanks to Kevin Gurney and the Department of Earth and Atmospheric
Sciences at Purdue University for data handling and ftp site hosting. We
thank Cathy Trudinger for helpful comments on the manuscript. Suggestion
from Philippe Peylin on correlations versus model resolution is
appreciated. Individual modeling groups acknowledge the following
support. CCAM: Part of this work was supported through the Australian
Greenhouse Office. We thank John McGregor and Eva Kowalczyk for their
development of CCAM. DEHM:Part of the work has been carried out within
the CarboEurope-IP project funded by the European Commission. LLNL: The
project (06-ERD-031) was funded by the Laboratory Directed Research and
Development Program at LLNL. IFS: The work has been funded by EU's GEMS
project SIP4-CT-2004-516099. CHIMERE is a model developed by IPSL,
INERIS and LISA. Part of the implementation of CHIMERE-CO2
has been supported through the French Environment and Energy Management
Agency (ADEME) and the French Atomic Energy Commission (CEA). PKP is
partly supported by the grants-in-aid for Creative Scientific Research
(2005/17GS0203) of the Ministry of Education, Science, Sports and
Culture, Japan; he wishes to thank Hajime Akimoto and Takakiyo Nakazawa
for useful discussions and supporting this research at FRCGC. We
sincerely thank the reviewers and associate editor James Randerson for
providing critical comments to improve the quality of the article.
NR 47
TC 54
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U1 0
U2 13
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0886-6236
J9 GLOBAL BIOGEOCHEM CY
JI Glob. Biogeochem. Cycle
PD NOV 26
PY 2008
VL 22
IS 4
AR GB4013
DI 10.1029/2007GB003081
PG 16
WC Environmental Sciences; Geosciences, Multidisciplinary; Meteorology &
Atmospheric Sciences
SC Environmental Sciences & Ecology; Geology; Meteorology & Atmospheric
Sciences
GA 377IH
UT WOS:000261244400001
ER
PT J
AU Stockli, R
Rutishauser, T
Dragoni, D
O'Keefe, J
Thornton, PE
Jolly, M
Lu, L
Denning, AS
AF Stoeckli, R.
Rutishauser, T.
Dragoni, D.
O'Keefe, J.
Thornton, P. E.
Jolly, M.
Lu, L.
Denning, A. S.
TI Remote sensing data assimilation for a prognostic phenology model
SO JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES
LA English
DT Review
ID CARBON-DIOXIDE EXCHANGE; VEGETATION LEAF-AREA; CLIMATE-CHANGE;
TIME-SERIES; LAND-COVER; INTERANNUAL VARIABILITY; PARAMETER-ESTIMATION;
SPRING PHENOLOGY; PLANT PHENOLOGY; VAPOR EXCHANGE
AB Predicting the global carbon and water cycle requires a realistic representation of vegetation phenology in climate models. However most prognostic phenology models are not yet suited for global applications, and diagnostic satellite data can be uncertain and lack predictive power. We present a framework for data assimilation of Fraction of Photosynthetically Active Radiation absorbed by vegetation (FPAR) and Leaf Area Index (LAI) from the MODerate Resolution Imaging Spectroradiometer (MODIS) to constrain empirical temperature, light, moisture and structural vegetation parameters of a prognostic phenology model. We find that data assimilation better constrains structural vegetation parameters than climate control parameters. Improvements are largest for drought-deciduous ecosystems where correlation of predicted versus satellite-observed FPAR and LAI increases from negative to 0.7-0.8. Data assimilation effectively overcomes the cloud- and aerosol-related deficiencies of satellite data sets in tropical areas. Validation with a 49-year-long phenology data set reveals that the temperature-driven start of season (SOS) is light limited in warm years. The model has substantial skill (R = 0.73) to reproduce SOS inter-annual and decadal variability. Predicted SOS shows a higher inter-annual variability with a negative bias of 5-20 days compared to species-level SOS. It is however accurate to within 1-2 days compared to SOS derived from net ecosystem exchange (NEE) measurements at a FLUXNET tower. The model only has weak skill to predict end of season (EOS). Use of remote sensing data assimilation for phenology model development is encouraged but validation should be extended with phenology data sets covering mediterranean, tropical and arctic ecosystems.
C1 [Stoeckli, R.] MeteoSwiss, Climate Serv, Climate Anal, Fed Off Meteorol & Climatol, CH-8044 Zurich, Switzerland.
[Stoeckli, R.; Lu, L.; Denning, A. S.] Colorado State Univ, Dept Atmospher Sci, Ft Collins, CO 80523 USA.
[Dragoni, D.] Indiana Univ, Atmospher Sci Programme, Dept Geog, Bloomington, IN 47405 USA.
[Jolly, M.] US Forest Serv, RMRS, Missoula, MT 59801 USA.
[O'Keefe, J.] Harvard Univ, Fisher Museum, Petersham, MA 01366 USA.
[Rutishauser, T.] Univ Bern, Inst Geog, Oeschger Ctr Climate Res, CH-3012 Bern, Switzerland.
[Thornton, P. E.] Natl Ctr Atmospher Res, Terr Sci Sect, Oak Ridge, TN USA.
[Stoeckli, R.] NASA, Earth Observ, Goddard Space Flight Ctr, Greenbelt, MD USA.
RP Stockli, R (reprint author), MeteoSwiss, Climate Serv, Climate Anal, Fed Off Meteorol & Climatol, Krahbuhlstr 58, CH-8044 Zurich, Switzerland.
EM reto.stoeckli@meteoswiss.ch
RI Thornton, Peter/B-9145-2012; Denning, Scott/F-4974-2011
OI Thornton, Peter/0000-0002-4759-5158; Denning, Scott/0000-0003-3032-7875
FU NASA Energy and Water Cycle Study (NEWS) [NNG06CG42G]; Science System
and Application Inc. [2207-06-016]; NASA [NAS5-02041]
FX The NASA Energy and Water Cycle Study (NEWS) grant No. NNG06CG42G is the
main funding source of this study. Computing resources were mainly
provided by sub-contract 2207-06-016 issued by Science System and
Application Inc. through NASA contract NAS5-02041. The MODIS Science
Team and the MODIS Science Data Support Team provided the MOD15A2 and
the MOD12Q1 data. Meteorological predictor data have been provided by
the site PI's and their teams participating in the CarboEurope IP,
AmeriFlux and LBA projects as part of FLUXNET: Marc Aubinet (Vielsalm),
Christian Bernhofer (Tharandt), Riccardo Valentini (Castelporziano and
Collelongo), Tuomas Laurila (Kaamanen), Timo Vesala (Hyytiala), Maria
Jose Sanz (El Saler), Serge Rambal (Puechabon), Andre Granier
(Sarrebourg), Mike Goulden (Santarem Km83), Steven Wofsy (Santarem Km67
and BOREAS NSA Old Black Spruce), Hans Peter Schmid (Morgan Monroe State
Forest), Brian Amiro (BOREAS NSA Old Black Spruce), Lawrence Flanagan
(Lethbridge), Tilden Meyers (Fort Peck and Bondville), Bill Munger
(Harvard Forest) and Russ Monson (Niwot Ridge), Kyaw Paw U (Wind River)
and Dennis Baldocchi (Tonzi and Vaira Ranch). The first author is
grateful to Arif Albaryrak (NASA/GSFC GMAO) for his advice and comments
on the ensemble data assimilation methodology.
NR 114
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U1 4
U2 45
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 2169-8953
EI 2169-8961
J9 J GEOPHYS RES-BIOGEO
JI J. Geophys. Res.-Biogeosci.
PD NOV 26
PY 2008
VL 113
IS G4
AR G04021
DI 10.1029/2008JG000781
PG 19
WC Environmental Sciences; Geosciences, Multidisciplinary
SC Environmental Sciences & Ecology; Geology
GA 377IQ
UT WOS:000261245300003
ER
PT J
AU Han, SC
AF Han, Shin-Chan
TI Improved regional gravity fields on the Moon from Lunar Prospector
tracking data by means of localized spherical harmonic functions
SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS
LA English
DT Article
ID ELASTIC THICKNESS; VENUS GRAVITY; 180TH DEGREE; ORDER MODEL; MARS;
TOPOGRAPHY; MASCONS; SPECTRA; MISSION; BASINS
AB An approach to enhance regional gravity fields of the planets using the line-of-sight (LOS) Doppler range-rate measurements is presented. Instead of representing the gravity fields as nonlocalized spherical harmonic functions, I introduced a lumped harmonic representation for obtaining regionally concentrated orthogonal basis functions. Without any regularization or spectral power control, the gravity fields over the four spherical cap regions with the radius of 20 degrees on the nearside of the Moon to degree and order 200 were estimated using all 8 months of the extended mission data from Lunar Prospector. The regional models are variations on the initial global gravity model LP100J. It was found that the regional estimates significantly improve the initial gravity model at all four regions of interest. My improved gravity models fit the LOS Doppler range-acceleration data better than any other global lunar gravity model, especially the data for when the satellite was at low altitude (40 km or less). In addition, a better cross correlation with the topography was obtained from the regional model. The regional enhancement of the correlation was prominent in degrees greater than 100 and in polar regions characterized by clusters of medium- or small-size craters that are presumably uncompensated.
C1 [Han, Shin-Chan] NASA, Goddard Space Flight Ctr, Planetary Geodynam Lab, Greenbelt, MD 20771 USA.
[Han, Shin-Chan] Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21228 USA.
RP Han, SC (reprint author), NASA, Goddard Space Flight Ctr, Planetary Geodynam Lab, Code 698, Greenbelt, MD 20771 USA.
EM shin-chan.han@nasa.gov
RI Han, Shin-Chan/A-2022-2009
FU NASA Earth Surface and Interior program; Gravity Recovery And Climate
Experiment project
FX This work was partially supported by the NASA Earth Surface and Interior
program and Gravity Recovery And Climate Experiment project. David
Rowlands, Frank Lemoine, and Gregory Neumann are acknowledged for their
helpful comments on an earlier version of this paper. Alex Konopliv is
acknowledged for information about the Lunar Prospector data available
from PDS Geosciences node (http://pds-geosciences.wustl.edu). I thank
Mark Wieczorek, Francis Nimmo, and an anonymous reviewer for
constructive reviews. I acknowledge an anonymous reviewer for the
comment on increased S-band measurement error when the spacecraft was
orbiting near the limb.
NR 31
TC 13
Z9 13
U1 1
U2 2
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 2169-9097
J9 J GEOPHYS RES-PLANET
JI J. Geophys. Res.-Planets
PD NOV 26
PY 2008
VL 113
IS E11
AR E11012
DI 10.1029/2008JE003166
PG 15
WC Geochemistry & Geophysics
SC Geochemistry & Geophysics
GA 377IV
UT WOS:000261245800002
ER
PT J
AU Han, SC
Sauber, J
Luthcke, SB
Ji, C
Pollitz, FF
AF Han, Shin-Chan
Sauber, Jeanne
Luthcke, Scott B.
Ji, Chen
Pollitz, Fred F.
TI Implications of postseismic gravity change following the great 2004
Sumatra-Andaman earthquake from the regional harmonic analysis of GRACE
intersatellite tracking data
SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
LA English
DT Article
ID LAYERED SPHERICAL EARTH; SATELLITE GRAVITY; GPS MEASUREMENTS; STATIC
OFFSETS; COSEISMIC SLIP; DEFORMATION; CONSTRAINTS; RELAXATION;
AFTERSLIP; DECEMBER
AB We report Gravity Recovery and Climate Experiment (GRACE) satellite observations of coseismic displacements and postseismic transients from the great Sumatra-Andaman Islands (thrust event; M-w similar to 9.2) earthquake in December 2004. Instead of using global spherical harmonic solutions of monthly gravity fields, we estimated the gravity changes directly using intersatellite range-rate data with regionally concentrated spherical Slepian basis functions every 15-day interval. We found significant step-like (coseismic) and exponential-like (postseismic) behavior in the time series of estimated coefficients (from May 2003 to April 2007) for the spherical Slepian functions. After deriving coseismic slip estimates from seismic and geodetic data that spanned different time intervals, we estimated and evaluated postseismic relaxation mechanisms with alternate asthenosphere viscosity models. The large spatial coverage and uniform accuracy of our GRACE solution enabled us to clearly delineate a postseismic transient signal in the first 2 years of postearthquake GRACE data. Our preferred interpretation of the long-wavelength components of the postseismic gravity change is biviscous viscoelastic flow. We estimated a transient viscosity of 5 x 10(17) Pa s and a steady state viscosity of 5 x 10(18) - 10(19) Pa s. Additional years of the GRACE observations should provide improved steady state viscosity estimates. In contrast to our interpretation of coseismic gravity change, the prominent postearthquake positive gravity change around the Nicobar Islands is accounted for by seafloor uplift with less postseismic perturbation in intrinsic density in the region surrounding the earthquake.
C1 [Han, Shin-Chan; Sauber, Jeanne; Luthcke, Scott B.] NASA, Goddard Space Flight Ctr, Planetary Geodynam Lab, Greenbelt, MD 20771 USA.
[Ji, Chen] Univ Calif Santa Barbara, Dept Earth Sci, Santa Barbara, CA 93106 USA.
[Pollitz, Fred F.] US Geol Survey, Menlo Pk, CA 94025 USA.
[Han, Shin-Chan] Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD USA.
RP Han, SC (reprint author), NASA, Goddard Space Flight Ctr, Planetary Geodynam Lab, Code 698, Greenbelt, MD 20771 USA.
EM Shin-Chan.Han@nasa.gov
RI Luthcke, Scott/D-6283-2012; Sauber, Jeanne/D-7684-2012; Han,
Shin-Chan/A-2022-2009
FU U.S. National Aeronautical and Space Administration GRACE; Earth Surface
and Interior program
FX This work was supported by the U.S. National Aeronautical and Space
Administration GRACE project and Earth Surface and Interior program. We
acknowledge the NASA/GFZ GRACE project for the GRACE data products
(distributed by JPL PODAAC) and colleagues at JPL for producing the
quality Level 1B products. This work also benefited from the Goddard
Space Flight Center's GEODYN software for computing the precise orbits.
We thank Mohamed Chlieh for his afterslip model and Frederik Simons for
clarification on the use of the spherical Slepian function. VISCO1D
software and its upgrade with computation of the gravity component were
used for the viscoelastic calculations. Some FORTRAN codes written by
Mark Wieczorek were used (available at www.ipgp.jussieu.fr/similar to
wieczor/SHTOOLS). We thank Roland Burgmann, Kelin Wang, and an anonymous
reviewer for constructive comments.
NR 36
TC 36
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U1 0
U2 4
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 2169-9313
EI 2169-9356
J9 J GEOPHYS RES-SOL EA
JI J. Geophys. Res.-Solid Earth
PD NOV 26
PY 2008
VL 113
IS B11
AR B11413
DI 10.1029/2008JB005705
PG 13
WC Geochemistry & Geophysics
SC Geochemistry & Geophysics
GA 377JA
UT WOS:000261246300004
ER
PT J
AU Gamayunov, KV
Khazanov, GV
AF Gamayunov, K. V.
Khazanov, G. V.
TI Crucial role of ring current H+ in electromagnetic ion cyclotron wave
dispersion relation: Results from global simulations
SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
LA English
DT Article
ID ELECTRIC-FIELD OBSERVATIONS; 1-2 MAGNETIC PULSATIONS; PITCH-ANGLE
SCATTERING; EQUATORIAL MAGNETOSPHERE; PC-1 WAVES; INNER MAGNETOSPHERE;
GEOMAGNETIC STORMS; SYNCHRONOUS ORBIT; MODEL; PLASMAPAUSE
AB The effect of ring current (RC) H+ in the real part of electromagnetic ion cyclotron (EMIC) wave dispersion relation is studied on the global magnetospheric scale. The simulations of the 2-3 May 1998 storm are done using our model of the He+-mode EMIC waves self-consistently interacting with RC ions. The wave model describes EMIC waves bouncing between the off-equatorial magnetic latitudes, which correspond to the bi-ion hybrid frequencies in conjugate hemispheres, along with tunneling across the reflection zones and subsequent strong absorption in the ionosphere. This model explicitly includes the EMIC wave growth/damping, propagation, refraction, reflection, and tunneling in a multi-ion magnetospheric plasma. An analysis of the wave observations is presented and strongly supports our wave model. The main findings from our simulations can be summarized as follows: First, RC H+ only contributes a few percent to the total plasma density near the inner edge of the plasmasphere boundary layer, but it can dominate outside the plasmapause. About 90% of the RC H+ density in the dawn MLT sector is formed by the suprathermal ions (less than or similar to 2 keV), while a major contribution in dusk comes from the 10-100 keV ions, allowing not more than 10-20% for the suprathermal ions. Second, RC H+ in the real part of the wave dispersion relation increases local growth rate leading to a dramatic change in the wave global patterns. The "new'' EMIC waves are generated not only on the plasmapause, as expected from previous global simulations, but also inside and outside the plasmapause consistent with the observations.
C1 [Gamayunov, K. V.] NASA, George C Marshall Space Flight Ctr, Univ Space Res Assoc, Natl Space Sci & Technol Ctr,Space Sci Dept, Huntsville, AL 35805 USA.
[Khazanov, G. V.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
RP Gamayunov, KV (reprint author), NASA, George C Marshall Space Flight Ctr, Univ Space Res Assoc, Natl Space Sci & Technol Ctr,Space Sci Dept, 320 Sparkman Dr, Huntsville, AL 35805 USA.
EM konstantin.gamayunov-1@nasa.gov; george.v.khazanov@nasa.gov
RI Gamayunov, Konstantin/A-8505-2009; feggans, john/F-5370-2012
OI Gamayunov, Konstantin/0000-0002-8768-8527;
FU NASA [UPN 370-16-10]
FX We would like to thank M. Thomsen for providing LANL data. Funding in
support of this study was provided by NASA grant UPN 370-16-10, NASA HQ
POLAR Project and NASA LWS Program.
NR 81
TC 15
Z9 15
U1 0
U2 2
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 2169-9380
EI 2169-9402
J9 J GEOPHYS RES-SPACE
JI J. Geophys. Res-Space Phys.
PD NOV 26
PY 2008
VL 113
IS A11
AR A11220
DI 10.1029/2008JA013494
PG 20
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 377JM
UT WOS:000261247500002
ER
PT J
AU Malingre, M
Berthelier, JJ
Pfaff, R
Jasperse, J
Parrot, M
AF Malingre, M.
Berthelier, J. -J.
Pfaff, R.
Jasperse, J.
Parrot, M.
TI Lightning-induced lower-hybrid turbulence and trapped Extremely Low
Frequency (ELF) electromagnetic waves observed in deep equatorial plasma
density depletions during intense magnetic storms
SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
LA English
DT Article
ID TRANSVERSE ION-ACCELERATION; PROCESSING ONBOARD DEMETER; SOLITARY
STRUCTURES; SCIENTIFIC OBJECTIVES; AURORAL IONOSPHERE; FIELD EXPERIMENT;
LINE RADIATION; JULY 15; BUBBLES; CAVITIES
AB During the early phase of the intense magnetic storm of 7-11 November 2004, the DEMETER satellite encountered large-scale equatorial plasma density depletions with density decreases of two or three orders of magnitude. Wave measurements carried out inside these depletions show the occurrence of broadband and localized lower-hybrid turbulence triggered by whistlers propagating from thunderstorm lightning occurring below the orbit path. High-sample-rate waveforms reveal that this lower-hybrid turbulence can evolve into localized large-amplitude quasi-monochromatic wave packets similar to lower-hybrid structures that were, up to now, only observed in the auroral regions, usually on high-latitude magnetic field lines associated with discrete aurora. These equatorial structures have typical amplitudes of up to 20 mV/m and durations of similar to 20-30 ms. Simultaneous thermal ion measurements show that these bursts are often correlated with small-scale density depletions of 5-10%. Although the lower-hybrid structures are less intense than those observed in the auroral zone and although their energy source is different, our observations lend support to the idea that the formation of lower-hybrid structures is an universal mechanism operating in inhomogeneous magnetized space plasmas in the presence of VLF whistler mode turbulence. Besides the lower-hybrid turbulence, another interesting feature is the occurrence of strong narrowband electromagnetic ELF emissions with amplitudes of a few millivolts per meter at frequencies below the proton gyrofrequency. They are continuously observed throughout the entire depletion. These emissions occur not only within the depletions but also, although less intense, outside of them over a large latitudinal range. They are tentatively identified as magnetospheric line radiations (MLRs) commonly observed during magnetically disturbed periods. Similar events were observed on 15 May 2005 and on 24 August 2005 during two other intense magnetic storms.
C1 [Malingre, M.; Berthelier, J. -J.] CNRS, Ctr Etude Environm Terrestre & Planetaires, F-94107 St Maur Des Fosses, France.
[Pfaff, R.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
[Jasperse, J.] Hanscom AFB, AF Res Lab, Bedford, MA USA.
[Parrot, M.] Lab Phys & Chim Environm, Orleans, France.
RP Malingre, M (reprint author), CNRS, Ctr Etude Environm Terrestre & Planetaires, 4 Ave Neptune, F-94107 St Maur Des Fosses, France.
EM michel.malingre@cetp.ipsl.fr
RI Pfaff, Robert/F-5703-2012
OI Pfaff, Robert/0000-0002-4881-9715
FU CNES [DEMETER/736/7621]; Air Force Office of Scientific Research
FX This work was supported by funding from CNES under DEMETER/736/7621
grants from 1999 to 2004. J.J. was supported by the
Windows-on-Europe-Program at the Air Force Office of Scientific
Research.
NR 49
TC 2
Z9 2
U1 1
U2 1
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 2169-9380
EI 2169-9402
J9 J GEOPHYS RES-SPACE
JI J. Geophys. Res-Space Phys.
PD NOV 26
PY 2008
VL 113
IS A11
AR A11320
DI 10.1029/2008JA013463
PG 17
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 377JM
UT WOS:000261247500001
ER
PT J
AU Molotch, NP
Meixner, T
Williams, MW
AF Molotch, Noah P.
Meixner, Thomas
Williams, Mark W.
TI Estimating stream chemistry during the snowmelt pulse using a spatially
distributed, coupled snowmelt and hydrochemical modeling approach
SO WATER RESOURCES RESEARCH
LA English
DT Article
ID HIGH-ELEVATION CATCHMENTS; WESTERN UNITED-STATES; COLORADO FRONT RANGE;
GREEN LAKES VALLEY; SIERRA-NEVADA; ROCKY-MOUNTAINS; EMERALD-LAKE;
ADIRONDACK REGION; ACID DEPOSITION; ENERGY-BALANCE
AB We used remotely sensed snow cover data and a physically based snowmelt model to estimate the spatial distribution of energy fluxes, snowmelt, snow water equivalent, and snow cover extent over the different land cover types within the Green Lakes Valley, Front Range, Colorado. The spatially explicit snowpack model was coupled to the Alpine Hydrochemical Model (AHM), and estimates of hydrochemistry at the basin outlflow were compared with the baseline AHM approach, which implicitly prescribes snowmelt. The proportions of total meltwater production from soil, talus, and rock subunits were 46, 25, and 29%, respectively, for the baseline simulation without our advanced snowmelt representation. Conversely, simulations in which the AHM was coupled to our distributed snowmelt model ascribed the largest meltwater production to talus (47%) subunits, with 37% ascribed to soil and 16% ascribed to rock. Accounting for these differences in AHM reduced model overestimates of cation concentration during snowmelt; modeled Ca(2+) estimates explained 82 and 70% (P values < 0.01) of observations with and without the coupled model, respectively. Similarly, the coupled model explained more variability in nitrate concentrations, with 83 versus 70% (P values < 0.01) explained by the coupled and baseline models, respectively. Early snowmelt over talus subunits was not detected at the basin outflow, confirming earlier reports that deeper flow paths are needed in biogeochemical models of alpine systems. Realistic treatment of snowmelt within these models will allow efforts to improve understanding of flow paths and predict catchment response to increases in atmospheric deposition and climate change.
C1 [Molotch, Noah P.] Univ Calif Los Angeles, Dept Civil & Environm Engn, Los Angeles, CA USA.
[Meixner, Thomas] Univ Arizona, Dept Hydrol & Water Resources, Tucson, AZ 85721 USA.
[Williams, Mark W.] Univ Colorado, Inst Arct & Alpine Res, Boulder, CO 80302 USA.
[Williams, Mark W.] Univ Colorado, Dept Geog, Boulder, CO 80302 USA.
RP Molotch, NP (reprint author), CALTECH, Jet Prop Lab, Water & Carbon Cycles Grp, Mail Stop 300-233,4800 Oak Grove Dr,, Pasadena, CA 91109 USA.
EM noah.p.molotch@jpl.nasa.gov
RI Molotch, Noah/C-8576-2009
FU National Science Foundation Hydrologic Sciences [EAR-0739107,
EAR-0711600]; NSF through the Niwot Ridge Long-Term Ecological Research,
NSF [EAR-0515592, EAR-0094312]; Consortium of Universities for the
Advancement of Hydrologic Science, Inc. [NSF EAR-0610112]
FX Support for this work was provided by the National Science Foundation
Hydrologic Sciences program (EAR-0739107 and EAR-0711600). Additional
support was provided by NSF through the Niwot Ridge Long-Term Ecological
Research program, NSF EAR-0515592, and EAR-0094312. Support from the
Consortium of Universities for the Advancement of Hydrologic Science,
Inc. WATERS test bed program (NSF EAR-0610112) is also acknowledged.
NR 65
TC 7
Z9 7
U1 1
U2 19
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0043-1397
J9 WATER RESOUR RES
JI Water Resour. Res.
PD NOV 26
PY 2008
VL 44
IS 11
AR W11429
DI 10.1029/2007WR006587
PG 14
WC Environmental Sciences; Limnology; Water Resources
SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water
Resources
GA 377KN
UT WOS:000261250200003
ER
PT J
AU DeFries, RS
Morton, DC
van der Werf, GR
Giglio, L
Collatz, GJ
Randerson, JT
Houghton, RA
Kasibhatla, PK
Shimabukuro, Y
AF DeFries, R. S.
Morton, D. C.
van der Werf, G. R.
Giglio, L.
Collatz, G. J.
Randerson, J. T.
Houghton, R. A.
Kasibhatla, P. K.
Shimabukuro, Y.
TI Fire-related carbon emissions from land use transitions in southern
Amazonia
SO GEOPHYSICAL RESEARCH LETTERS
LA English
DT Article
ID TROPICAL DEFORESTATION; ATMOSPHERIC CO2; FORESTS
AB Various land-use transitions in the tropics contribute to atmospheric carbon emissions, including forest conversion for small-scale farming, cattle ranching, and production of commodities such as soya and palm oil. These transitions involve fire as an effective and inexpensive means for clearing. We applied the DECAF (DEforestation CArbon Fluxes) model to Mato Grosso, Brazil to estimate fire emissions from various land-use transitions during 2001-2005. Fires associated with deforestation contributed 67 Tg C/yr (17 and 50 Tg C/yr from conversion to cropland and pasture, respectively), while conversion of savannas and existing cattle pasture to cropland contributed 17 Tg C/yr and pasture maintenance fires 6 Tg C/yr. Large clearings (>100 ha/yr) contributed 67% of emissions but comprised only 10% of deforestation events. From a policy perspective, results imply that intensification of agricultural production on already-cleared land and policies to discourage large clearings would reduce the major sources of emissions from fires in this region. Citation: DeFries, R. S., D. C. Morton, G. R. van der Werf, L. Giglio, G. J. Collatz, J. T. Randerson, R. A. Houghton, P. K. Kasibhatla, and Y. Shimabukuro (2008), Fire-related carbon emissions from land use transitions in southern Amazonia, Geophys. Res. Lett., 35, L22705, doi:10.1029/2008GL035689.
C1 [DeFries, R. S.] Columbia Univ, Dept Ecol Evolut & Environm Biol, New York, NY 10027 USA.
[Collatz, G. J.] NASA, Goddard Space Flight Ctr, Biospher Sci Branch, Greenbelt, MD 20771 USA.
[Morton, D. C.; Giglio, L.] Univ Maryland, Dept Geog, College Pk, MD 20742 USA.
[Houghton, R. A.] Woods Hole Res Ctr, Falmouth, MA 02543 USA.
[Kasibhatla, P. K.] Duke Univ, Nicholas Sch Environm & Earth Sci, Durham, NC 27708 USA.
[Randerson, J. T.] Univ Calif Irvine, Dept Earth Syst Sci, Irvine, CA 92697 USA.
[Shimabukuro, Y.] Inst Nacl Pesquisas Espaciais, Remote Sensing Div, BR-12227010 Sao Jose Dos Campos, SP, Brazil.
[van der Werf, G. R.] Vrije Univ Amsterdam, Dept Hydrol & Geo Environm Sci, Fac Earth & Life Sci, NL-1018 HV Amsterdam, Netherlands.
RP DeFries, RS (reprint author), Columbia Univ, Dept Ecol Evolut & Environm Biol, 1200 Amsterdam Ave, New York, NY 10027 USA.
EM rd2402@columbia.edu
RI collatz, george/D-5381-2012; Morton, Douglas/D-5044-2012; van der Werf,
Guido/M-8260-2016;
OI van der Werf, Guido/0000-0001-9042-8630; Kasibhatla,
Prasad/0000-0003-3562-3737
FU NASA [NNG05GD20G, NNG04GK49G, NNX08AL03G]; Netherlands Organization for
Scientific Research
FX This research was supported by NASA grants NNG05GD20G, NNG04GK49G, and
NNX08AL03G (PSK). GRvdW was supported by a Veni grant from the
Netherlands Organization for Scientific Research.
NR 19
TC 22
Z9 22
U1 1
U2 19
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0094-8276
J9 GEOPHYS RES LETT
JI Geophys. Res. Lett.
PD NOV 25
PY 2008
VL 35
IS 22
AR L22705
DI 10.1029/2008GL035689
PG 5
WC Geosciences, Multidisciplinary
SC Geology
GA 377ID
UT WOS:000261244000002
ER
PT J
AU Tam, CKW
Viswanathan, K
Ahuja, KK
Panda, J
AF Tam, Christopher K. W.
Viswanathan, K.
Ahuja, K. K.
Panda, J.
TI The sources of jet noise: experimental evidence
SO JOURNAL OF FLUID MECHANICS
LA English
DT Article
ID HIGH-SPEED JETS; SIMULTANEOUS ACOUSTIC MEASUREMENTS; TURBULENT MIXING
NOISE; DENSITY-FLUCTUATIONS; AERODYNAMIC NOISE; INSTABILITY WAVES;
SUPERSONIC FLOWS; LAYERS; SOUND; PREDICTIONS
AB The primary objective,of this investigation is to determine experimentally the sources of jet mixing noise. In the present study, four different approaches are used. It is reasonable to assume that the characteristics of the noise sources are imprinted on their radiation fields. Under this assumption, it becornes possible to analyse the characteristics of the far-field sound and then infer back to the characteristics of the sources. The first approach is to make use of the spectral and directional information measured by a single microphone in the far field. A detailed analysis of a large collection of far-field noise data has been carried out. The purpose is to identify special characteristics that can be linked directly to those of the sources. The second approach is to measure the coherence of the sound field using two microphones. The autocorrelations and cross-correlations of these measurements offer not only valuable information on the spatial structure of the noise field in the radial and polar angle directions, but also on the sources inside the jet. The third approach involves measuring the correlation between turbulence fluctuations inside a jet and the radiated noise in the far field. This is the most direct and unambiguous way of identifying the sources of jet noise. In the fourth approach, a mirror microphone is used to measure the noise source distribution along the lengths of high-speed jets. Features and trends observed in noise source strength distributions are expected to shed light on the source mechanisms. It will be shown that all four types of data indicate clearly the existence of two distinct noise sources in jets. One source of noise is the fine-scale turbulence and the other source is the large turbulence structures of the jet flow. Some of the salient features of the sound field associated with the two noise sources are reported in this paper.
C1 [Tam, Christopher K. W.] Florida State Univ, Tallahassee, FL 32306 USA.
[Viswanathan, K.] Boeing Co, Seattle, WA 98124 USA.
[Ahuja, K. K.] Georgia Inst Technol, Atlanta, GA 30332 USA.
[Panda, J.] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
RP Tam, CKW (reprint author), Florida State Univ, Tallahassee, FL 32306 USA.
EM tam@math.fsu.edu
FU NASA Vehicle Systems Program; Department of Defense Research and
Engineering (DDRE)
FX The authors are grateful to Georgia Tech students Donald Kirby Nance and
Brian Cook for acquiring the microphone far-field noise
cross-correlation data. They also wish to thank Dr Nikolal Pastouchenko
of Florida State University for his assistance in processing the single
microphone noise measurements. The work of C. K. W. T was partially
Supported by a contract from the Boeing Company. K. V. is the Technical
Monitor and the Boeing Principal Investigator for the project. Georgia
Tech work was sponsored by the NASA Vehicle Systems Program and the
Department of Defense Research and Engineering (DDR&E) under the scope
of the Aeropropulsion University Research Engineering Technology
Institute (URETI).
NR 57
TC 111
Z9 120
U1 3
U2 21
PU CAMBRIDGE UNIV PRESS
PI NEW YORK
PA 32 AVENUE OF THE AMERICAS, NEW YORK, NY 10013-2473 USA
SN 0022-1120
J9 J FLUID MECH
JI J. Fluid Mech.
PD NOV 25
PY 2008
VL 615
BP 253
EP 292
DI 10.1017/S0022112008003704
PG 40
WC Mechanics; Physics, Fluids & Plasmas
SC Mechanics; Physics
GA 377LD
UT WOS:000261251800012
ER
PT J
AU Jacobson, NS
Roth, DJ
Rauser, RW
Cawley, JD
Curry, DM
AF Jacobson, Nathan S.
Roth, Don J.
Rauser, Richard W.
Cawley, James D.
Curry, Donald M.
TI Oxidation through coating cracks of SiC-protected carbon/carbon
SO SURFACE & COATINGS TECHNOLOGY
LA English
DT Article
DE Carbon/carbon; Oxidation; Coatings; Silicon carbide; Non-destructive
evaluation
ID 1D-SIC/C/SIC COMPOSITE-MATERIALS; CARBON-CARBON COMPOSITES; KINETICS;
MECHANISMS; CARBIDE; MATRIX
AB The oxidation Of SiC-protected carbon/carbon through machined slots and naturally occurring craze cracks in the SiC was studied. The slot and crack geometries were characterized, and the subsurface oxidation of the carbon/carbon substrate at temperatures of 1000 to 1300 degrees C in air was assessed using weight change, X-ray computed tomography, and optical microscopy of sections. Rate constants were derived from these measurements and compared with a two-step diffusion control model of carbon oxidation. This model included gas phase diffusion in the channel through the SiC coating and in the growing oxidation cavity within the substrate. Oxidation measurements from sections were the most accurate and also agreed well with the model. Oxidation measurements from weight loss were higher than the model which is likely due to other contributions to net weight loss besides oxidation. Published by Elsevier B.V.
C1 [Jacobson, Nathan S.; Roth, Don J.] NASA, Glenn Res Ctr, Cleveland, OH 44135 USA.
[Rauser, Richard W.] Univ Toledo, Toledo, OH 43006 USA.
[Cawley, James D.] Case Western Reserve Univ, Cleveland, OH 44106 USA.
[Curry, Donald M.] NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA.
RP Jacobson, NS (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA.
EM nathan.s.jacobson@nasa.gov
RI Jacobson, Nathan/A-9411-2009
NR 33
TC 65
Z9 68
U1 0
U2 15
PU ELSEVIER SCIENCE SA
PI LAUSANNE
PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND
SN 0257-8972
J9 SURF COAT TECH
JI Surf. Coat. Technol.
PD NOV 25
PY 2008
VL 203
IS 3-4
BP 372
EP 383
DI 10.1016/j.surfcoat.2008.09.013
PG 12
WC Materials Science, Coatings & Films; Physics, Applied
SC Materials Science; Physics
GA 378YH
UT WOS:000261360600027
ER
PT J
AU Ahn, C
Birnbaum, K
AF Ahn, Charlene
Birnbaum, Kevin
TI Reply to: "Comment on: 'Exposed-key weakness of alpha eta' [Phys. Lett.
A 370 (2007) 131]" [Phys. Lett. A 372 (2008) 7091]
SO PHYSICS LETTERS A
LA English
DT Editorial Material
AB We present simulations countering the claims in [R. Nair, H.P. Yuen, Phys. Lett. A 372 (2008) 7091] that the approximation given in [C. Ahn, K. Birnbaum, Phys. Lett. A 370 (2007) 131, quant-ph/0612058] for the eavesdropper's entropy on the encrypted key cannot be valid, and additionally discuss ways in which our views on security requirements differ from those given in [R. Nair. H.P. Yuen, Phys. Lett. A 372 (2008) 7091]. (C) 2008 Elsevier B.V. All rights reserved.
C1 [Birnbaum, Kevin] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[Ahn, Charlene] Toyon Res Corp, Goleta, CA 93117 USA.
RP Birnbaum, K (reprint author), CALTECH, Jet Prop Lab, M-S 161-135,4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM cahn@toyon.com; kevin.m.birnbaum@jpl.nasa.gov
NR 4
TC 1
Z9 1
U1 0
U2 0
PU ELSEVIER SCIENCE BV
PI AMSTERDAM
PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS
SN 0375-9601
J9 PHYS LETT A
JI Phys. Lett. A
PD NOV 24
PY 2008
VL 372
IS 47
BP 7097
EP 7099
DI 10.1016/j.physleta.2008.10.039
PG 3
WC Physics, Multidisciplinary
SC Physics
GA 384BY
UT WOS:000261719900020
ER
PT J
AU Clerbaux, C
Coheur, PF
Clarisse, L
Hadji-Lazaro, J
Hurtmans, D
Turquety, S
Bowman, K
Worden, H
Carn, SA
AF Clerbaux, C.
Coheur, P. -F.
Clarisse, L.
Hadji-Lazaro, J.
Hurtmans, D.
Turquety, S.
Bowman, K.
Worden, H.
Carn, S. A.
TI Measurements of SO(2) profiles in volcanic plumes from the NASA
Tropospheric Emission Spectrometer (TES)
SO GEOPHYSICAL RESEARCH LETTERS
LA English
DT Article
AB Satellite measurements are now recognized as a key element for the early detection and characterization of volcanic eruptions, in particular in the context of aircraft routing. A common tracer of volcanic plumes is sulfur dioxide (SO(2)), which so far has been measured by ultraviolet-visible (UV-vis) instruments and multispectral infrared (IR) sounders. Here we report the first SO(2) vertical profile retrieved from high spectral resolution thermal infrared nadir radiance spectra and we provide information on both the quantity of gas emitted and its altitude. From the radiance spectra provided by the Tropospheric Emission Spectrometer (TES) aboard the NASA AURA satellite, and owing to the similar to 0.1 cm(-1) (apodized) spectral resolution, elevated levels of SO(2) were measured following volcanic eruptions occurring in 2005 (Manam, Sierra Negra) and 2006 (Rabaul, Nyamuragira). Column values are found to be in good agreement with the data provided by Ozone Mapping Instrument (OMI), a UV-vis instrument also onboard the AURA satellite. Citation: Clerbaux, C., P.-F. Coheur, L. Clarisse, J. Hadji-Lazaro, D. Hurtmans, S. Turquety, K. Bowman, H. Worden, and S. A. Carn (2008), Measurements of SO(2) profiles in volcanic plumes from the NASA Tropospheric Emission Spectrometer (TES), Geophys. Res. Lett., 35, L22807, doi:10.1029/2008GL035566.
C1 [Clerbaux, C.; Hadji-Lazaro, J.; Turquety, S.] Univ Paris 06, CNRS, UMR 7620, Serv Aeron,IPSL, F-75252 Paris 05, France.
[Clerbaux, C.; Coheur, P. -F.; Clarisse, L.; Hurtmans, D.] Univ Libre Bruxelles, Serv Chim Quant & Photophys, B-1050 Brussels, Belgium.
[Bowman, K.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[Carn, S. A.] Univ Maryland, Joint Ctr Earth Syst Technol, Baltimore, MD 21201 USA.
RP Clerbaux, C (reprint author), Univ Paris 06, CNRS, UMR 7620, Serv Aeron,IPSL, 4 Pl Jussieu, F-75252 Paris 05, France.
EM ccl@aero.jussieu.fr
RI Clarisse, Lieven/C-3933-2011; clerbaux, cathy/I-5478-2013
OI Clarisse, Lieven/0000-0002-8805-2141;
FU CNES; Actions de Recherche Concertees (Communaute Francaise); Fonds
National de la Recherche Scientifique (FRS-FNRS) [F.4511.08]; Belgian
State Federal Office for Scientific, Technical and Cultural Affairs and
the European Space Agency (ESA-Prodex) [C90-327]; NASA's Science Mission
Directorate (Atmospheric Composition)
FX We thank the two reviewers for their useful comments. A. Jeulin (France)
and F. Stevens (Belgium) were involved in the initial steps of this
study. C. Clerbaux and S. Turquety are grateful to CNES for financial
support. The research in Belgium was funded by the "Actions de Recherche
Concertees'' (Communaute Francaise), the Fonds National de la Recherche
Scientifique (FRS-FNRS F.4511.08), the Belgian State Federal Office for
Scientific, Technical and Cultural Affairs and the European Space Agency
(ESA-Prodex C90-327). S. A. Carn acknowledges funding from NASA's
Science Mission Directorate (Atmospheric Composition) for OMI
SO2 validation. Contributions from K. Bowman and H. Worden
were performed at the Jet Propulsion Laboratory, California Institute of
Technology, under a contract with the National Aeronautics and Space
Administration. P.-F. Coheur and L. Clarisse are Research Associate and
Scientific Research Worker, respectively, with the F.N.R.S.
NR 26
TC 22
Z9 22
U1 0
U2 5
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0094-8276
J9 GEOPHYS RES LETT
JI Geophys. Res. Lett.
PD NOV 22
PY 2008
VL 35
IS 22
AR L22807
DI 10.1029/2008GL035566
PG 5
WC Geosciences, Multidisciplinary
SC Geology
GA 375WE
UT WOS:000261143700005
ER
PT J
AU Abbott, B
Abbott, R
Adhikari, R
Ajith, P
Allen, B
Allen, G
Amin, R
Anderson, SB
Anderson, WG
Arain, MA
Araya, M
Armandula, H
Armor, P
Aso, Y
Aston, S
Aufmuth, P
Aulbert, C
Babak, S
Ballmer, S
Bantilan, H
Barish, BC
Barker, C
Barker, D
Barr, B
Barriga, P
Barton, MA
Bartos, I
Bastarrika, M
Bayer, K
Betzwieser, J
Beyersdorf, PT
Bilenko, IA
Billingsley, G
Biswas, R
Black, E
Blackburn, K
Blackburn, L
Blair, D
Bland, B
Bodiya, TP
Bogue, L
Bork, R
Boschi, V
Bose, S
Brady, PR
Braginsky, VB
Brau, JE
Brinkmann, M
Brooks, A
Brown, DA
Brunet, G
Bullington, A
Buonanno, A
Burmeister, O
Byer, RL
Cadonati, L
Cagnoli, G
Camp, JB
Cannizzo, J
Cannon, K
Cao, J
Cardenas, L
Casebolt, T
Castaldi, G
Cepeda, C
Chalkley, E
Charlton, P
Chatterji, S
Chelkowski, S
Chen, Y
Christensen, N
Clark, D
Clark, J
Cokelaer, T
Conte, R
Cook, D
Corbitt, T
Coyne, D
Creighton, JDE
Cumming, A
Cunningham, L
Cutler, RM
Dalrymple, J
Danzmann, K
Davies, G
DeBra, D
Degallaix, J
Degree, M
Dergachev, V
Desai, S
DeSalvo, R
Dhurandhar, S
Diaz, M
Dickson, J
Dietz, A
Donovan, F
Dooley, KL
Doomes, EE
Drever, RWP
Duke, I
Dumas, JC
Dupuis, RJ
Dwyer, JG
Echols, C
Effler, A
Ehrens, P
Espinoza, E
Etzel, T
Evans, T
Fairhurst, S
Fan, Y
Fazi, D
Fehrmann, H
Fejer, MM
Finn, LS
Flasch, K
Fotopoulos, N
Freise, A
Frey, R
Fricke, T
Fritschel, P
Frolov, VV
Fyffe, M
Garofoli, J
Gholami, I
Giaime, JA
Giampanis, S
Giardina, KD
Goda, K
Goetz, E
Goggin, L
Gonzalez, G
Gossler, S
Gouaty, R
Grant, A
Gras, S
Gray, C
Gray, M
Greenhalgh, RJS
Gretarsson, AM
Grimaldi, F
Grosso, R
Grote, H
Grunewald, S
Guenther, M
Gustafson, EK
Gustafson, R
Hage, B
Hallam, JM
Hammer, D
Hanna, C
Hanson, J
Harms, J
Harry, G
Harstad, E
Hayama, K
Hayler, T
Heefner, J
Heng, IS
Hennessy, M
Heptonstall, A
Hewitson, M
Hild, S
Hirose, E
Hoak, D
Hosken, D
Hough, J
Huttner, SH
Ingram, D
Ito, M
Ivanov, A
Johnson, B
Johnson, WW
Jones, DI
Jones, G
Jones, R
Ju, L
Kalmus, P
Kalogera, V
Kamat, S
Kanner, J
Kasprzyk, D
Katsavounidis, E
Kawabe, K
Kawamura, S
Kawazoe, F
Kells, W
Keppel, DG
Khalili, FY
Khan, R
Khazanov, E
Kim, C
King, P
Kissel, JS
Klimenko, S
Kokeyama, K
Kondrashov, V
Kopparapu, RK
Kozak, D
Kozhevatov, I
Krishnan, B
Kwee, P
Lam, PK
Landry, M
Lang, MM
Lantz, B
Lazzarini, A
Lei, M
Leindecker, N
Leonhardt, V
Leonor, I
Libbrecht, K
Lin, H
Lindquist, P
Lockerbie, NA
Lodhia, D
Lormand, M
Lu, P
Lubinski, M
Lucianetti, A
Luck, H
Machenschalk, B
MacInnis, M
Mageswaran, M
Mailand, K
Mandic, V
Marka, S
Marka, Z
Markosyan, A
Markowitz, J
Maros, E
Martin, I
Martin, RM
Marx, JN
Mason, K
Matichard, F
Matone, L
Matzner, R
Mavalvala, N
McCarthy, R
McClelland, DE
McGuire, SC
McHugh, M
McIntyre, G
McIvor, G
McKechan, D
McKenzie, K
Meier, T
Melissinos, A
Mendell, G
Mercer, RA
Meshkov, S
Messenger, CJ
Meyers, D
Miller, J
Minelli, J
Mitra, S
Mitrofanov, VP
Mitselmakher, G
Mittleman, R
Miyakawa, O
Moe, B
Mohanty, S
Moreno, G
Mossavi, K
MowLowry, C
Mueller, G
Mukherjee, S
Mukhopadhyay, H
Muller-Ebhardt, H
Munch, J
Murray, P
Myers, E
Myers, J
Nash, T
Nelson, J
Newton, G
Nishizawa, A
Numata, K
O'Dell, J
Ogin, G
O'Reilly, B
O'Shaughnessy, R
Ottaway, DJ
Ottens, RS
Overmier, H
Owen, BJ
Pan, Y
Pankow, C
Papa, MA
Parameshwaraiah, V
Patel, P
Pedraza, M
Penn, S
Perreca, A
Petrie, T
Pinto, IM
Pitkin, M
Pletsch, HJ
Plissi, MV
Postiglione, F
Principe, M
Prix, R
Quetschke, V
Raab, F
Rabeling, DS
Radkins, H
Rainer, N
Rakhmanov, M
Ramsunder, M
Rehbein, H
Reid, S
Reitze, DH
Riesen, R
Riles, K
Rivera, B
Robertson, NA
Robinson, C
Robinson, EL
Roddy, S
Rodriguez, A
Rogan, AM
Rollins, J
Romano, JD
Romie, J
Route, R
Rowan, S
Rudiger, A
Ruet, L
Russell, P
Ryan, K
Sakata, S
Samidi, M
de la Jordana, LS
Sandberg, V
Sannibale, V
Saraf, S
Sarin, P
Sathyaprakash, BS
Sato, S
Saulson, PR
Savage, R
Savov, P
Schediwy, SW
Schilling, R
Schnabel, R
Schofield, R
Schutz, BF
Schwinberg, P
Scott, SM
Searle, AC
Sears, B
Seifert, F
Sellers, D
Sengupta, AS
Shawhan, P
Shoemaker, DH
Sibley, A
Siemens, X
Sigg, D
Sinha, S
Sintes, AM
Slagmolen, BJJ
Slutsky, J
Smith, JR
Smith, MR
Smith, ND
Somiya, K
Sorazu, B
Stein, LC
Stochino, A
Stone, R
Strain, KA
Strom, DM
Stuver, A
Summerscales, TZ
Sun, KX
Sung, M
Sutton, PJ
Takahashi, H
Tanner, DB
Taylor, R
Thacker, J
Thorne, KA
Thorne, KS
Thuring, A
Tokmakov, KV
Torres, C
Torrie, C
Traylor, G
Trias, M
Tyler, W
Ugolini, D
Ulmen, J
Urbanek, K
Vahlbruch, H
Van Den Broeck, C
van der Sluys, M
Vass, S
Vaulin, R
Vecchio, A
Veitch, J
Veitch, P
Villar, A
Vorvick, C
Vyachanin, SP
Waldman, SJ
Wallace, L
Ward, H
Ward, R
Weinert, M
Weinstein, A
Weiss, R
Wen, S
Wette, K
Whelan, JT
Whitcomb, SE
Whiting, BF
Wilkinson, C
Willems, PA
Williams, HR
Williams, L
Willke, B
Wilmut, I
Winkler, W
Wipf, CC
Wiseman, AG
Woan, G
Wooley, R
Worden, J
Wu, W
Yakushin, I
Yamamoto, H
Yan, Z
Yoshida, S
Zanolin, M
Zhang, J
Zhang, L
Zhao, C
Zotov, N
Zucker, M
Zweizig, J
Barthelmy, S
Gehrels, N
Hurley, KC
Palmer, D
AF Abbott, B.
Abbott, R.
Adhikari, R.
Ajith, P.
Allen, B.
Allen, G.
Amin, R.
Anderson, S. B.
Anderson, W. G.
Arain, M. A.
Araya, M.
Armandula, H.
Armor, P.
Aso, Y.
Aston, S.
Aufmuth, P.
Aulbert, C.
Babak, S.
Ballmer, S.
Bantilan, H.
Barish, B. C.
Barker, C.
Barker, D.
Barr, B.
Barriga, P.
Barton, M. A.
Bartos, I.
Bastarrika, M.
Bayer, K.
Betzwieser, J.
Beyersdorf, P. T.
Bilenko, I. A.
Billingsley, G.
Biswas, R.
Black, E.
Blackburn, K.
Blackburn, L.
Blair, D.
Bland, B.
Bodiya, T. P.
Bogue, L.
Bork, R.
Boschi, V.
Bose, S.
Brady, P. R.
Braginsky, V. B.
Brau, J. E.
Brinkmann, M.
Brooks, A.
Brown, D. A.
Brunet, G.
Bullington, A.
Buonanno, A.
Burmeister, O.
Byer, R. L.
Cadonati, L.
Cagnoli, G.
Camp, J. B.
Cannizzo, J.
Cannon, K.
Cao, J.
Cardenas, L.
Casebolt, T.
Castaldi, G.
Cepeda, C.
Chalkley, E.
Charlton, P.
Chatterji, S.
Chelkowski, S.
Chen, Y.
Christensen, N.
Clark, D.
Clark, J.
Cokelaer, T.
Conte, R.
Cook, D.
Corbitt, T.
Coyne, D.
Creighton, J. D. E.
Cumming, A.
Cunningham, L.
Cutler, R. M.
Dalrymple, J.
Danzmann, K.
Davies, G.
DeBra, D.
Degallaix, J.
Degree, M.
Dergachev, V.
Desai, S.
DeSalvo, R.
Dhurandhar, S.
Diaz, M.
Dickson, J.
Dietz, A.
Donovan, F.
Dooley, K. L.
Doomes, E. E.
Drever, R. W. P.
Duke, I.
Dumas, J. -C.
Dupuis, R. J.
Dwyer, J. G.
Echols, C.
Effler, A.
Ehrens, P.
Espinoza, E.
Etzel, T.
Evans, T.
Fairhurst, S.
Fan, Y.
Fazi, D.
Fehrmann, H.
Fejer, M. M.
Finn, L. S.
Flasch, K.
Fotopoulos, N.
Freise, A.
Frey, R.
Fricke, T.
Fritschel, P.
Frolov, V. V.
Fyffe, M.
Garofoli, J.
Gholami, I.
Giaime, J. A.
Giampanis, S.
Giardina, K. D.
Goda, K.
Goetz, E.
Goggin, L.
Gonzalez, G.
Gossler, S.
Gouaty, R.
Grant, A.
Gras, S.
Gray, C.
Gray, M.
Greenhalgh, R. J. S.
Gretarsson, A. M.
Grimaldi, F.
Grosso, R.
Grote, H.
Grunewald, S.
Guenther, M.
Gustafson, E. K.
Gustafson, R.
Hage, B.
Hallam, J. M.
Hammer, D.
Hanna, C.
Hanson, J.
Harms, J.
Harry, G.
Harstad, E.
Hayama, K.
Hayler, T.
Heefner, J.
Heng, I. S.
Hennessy, M.
Heptonstall, A.
Hewitson, M.
Hild, S.
Hirose, E.
Hoak, D.
Hosken, D.
Hough, J.
Huttner, S. H.
Ingram, D.
Ito, M.
Ivanov, A.
Johnson, B.
Johnson, W. W.
Jones, D. I.
Jones, G.
Jones, R.
Ju, L.
Kalmus, P.
Kalogera, V.
Kamat, S.
Kanner, J.
Kasprzyk, D.
Katsavounidis, E.
Kawabe, K.
Kawamura, S.
Kawazoe, F.
Kells, W.
Keppel, D. G.
Khalili, F. Ya.
Khan, R.
Khazanov, E.
Kim, C.
King, P.
Kissel, J. S.
Klimenko, S.
Kokeyama, K.
Kondrashov, V.
Kopparapu, R. K.
Kozak, D.
Kozhevatov, I.
Krishnan, B.
Kwee, P.
Lam, P. K.
Landry, M.
Lang, M. M.
Lantz, B.
Lazzarini, A.
Lei, M.
Leindecker, N.
Leonhardt, V.
Leonor, I.
Libbrecht, K.
Lin, H.
Lindquist, P.
Lockerbie, N. A.
Lodhia, D.
Lormand, M.
Lu, P.
Lubinski, M.
Lucianetti, A.
Lueck, H.
Machenschalk, B.
MacInnis, M.
Mageswaran, M.
Mailand, K.
Mandic, V.
Marka, S.
Marka, Z.
Markosyan, A.
Markowitz, J.
Maros, E.
Martin, I.
Martin, R. M.
Marx, J. N.
Mason, K.
Matichard, F.
Matone, L.
Matzner, R.
Mavalvala, N.
McCarthy, R.
McClelland, D. E.
McGuire, S. C.
McHugh, M.
McIntyre, G.
McIvor, G.
McKechan, D.
McKenzie, K.
Meier, T.
Melissinos, A.
Mendell, G.
Mercer, R. A.
Meshkov, S.
Messenger, C. J.
Meyers, D.
Miller, J.
Minelli, J.
Mitra, S.
Mitrofanov, V. P.
Mitselmakher, G.
Mittleman, R.
Miyakawa, O.
Moe, B.
Mohanty, S.
Moreno, G.
Mossavi, K.
MowLowry, C.
Mueller, G.
Mukherjee, S.
Mukhopadhyay, H.
Mueller-Ebhardt, H.
Munch, J.
Murray, P.
Myers, E.
Myers, J.
Nash, T.
Nelson, J.
Newton, G.
Nishizawa, A.
Numata, K.
O'Dell, J.
Ogin, G.
O'Reilly, B.
O'Shaughnessy, R.
Ottaway, D. J.
Ottens, R. S.
Overmier, H.
Owen, B. J.
Pan, Y.
Pankow, C.
Papa, M. A.
Parameshwaraiah, V.
Patel, P.
Pedraza, M.
Penn, S.
Perreca, A.
Petrie, T.
Pinto, I. M.
Pitkin, M.
Pletsch, H. J.
Plissi, M. V.
Postiglione, F.
Principe, M.
Prix, R.
Quetschke, V.
Raab, F.
Rabeling, D. S.
Radkins, H.
Rainer, N.
Rakhmanov, M.
Ramsunder, M.
Rehbein, H.
Reid, S.
Reitze, D. H.
Riesen, R.
Riles, K.
Rivera, B.
Robertson, N. A.
Robinson, C.
Robinson, E. L.
Roddy, S.
Rodriguez, A.
Rogan, A. M.
Rollins, J.
Romano, J. D.
Romie, J.
Route, R.
Rowan, S.
Ruediger, A.
Ruet, L.
Russell, P.
Ryan, K.
Sakata, S.
Samidi, M.
Sancho de la Jordana, L.
Sandberg, V.
Sannibale, V.
Saraf, S.
Sarin, P.
Sathyaprakash, B. S.
Sato, S.
Saulson, P. R.
Savage, R.
Savov, P.
Schediwy, S. W.
Schilling, R.
Schnabel, R.
Schofield, R.
Schutz, B. F.
Schwinberg, P.
Scott, S. M.
Searle, A. C.
Sears, B.
Seifert, F.
Sellers, D.
Sengupta, A. S.
Shawhan, P.
Shoemaker, D. H.
Sibley, A.
Siemens, X.
Sigg, D.
Sinha, S.
Sintes, A. M.
Slagmolen, B. J. J.
Slutsky, J.
Smith, J. R.
Smith, M. R.
Smith, N. D.
Somiya, K.
Sorazu, B.
Stein, L. C.
Stochino, A.
Stone, R.
Strain, K. A.
Strom, D. M.
Stuver, A.
Summerscales, T. Z.
Sun, K. -X.
Sung, M.
Sutton, P. J.
Takahashi, H.
Tanner, D. B.
Taylor, R.
Thacker, J.
Thorne, K. A.
Thorne, K. S.
Thuering, A.
Tokmakov, K. V.
Torres, C.
Torrie, C.
Traylor, G.
Trias, M.
Tyler, W.
Ugolini, D.
Ulmen, J.
Urbanek, K.
Vahlbruch, H.
Van Den Broeck, C.
van der Sluys, M.
Vass, S.
Vaulin, R.
Vecchio, A.
Veitch, J.
Veitch, P.
Villar, A.
Vorvick, C.
Vyachanin, S. P.
Waldman, S. J.
Wallace, L.
Ward, H.
Ward, R.
Weinert, M.
Weinstein, A.
Weiss, R.
Wen, S.
Wette, K.
Whelan, J. T.
Whitcomb, S. E.
Whiting, B. F.
Wilkinson, C.
Willems, P. A.
Williams, H. R.
Williams, L.
Willke, B.
Wilmut, I.
Winkler, W.
Wipf, C. C.
Wiseman, A. G.
Woan, G.
Wooley, R.
Worden, J.
Wu, W.
Yakushin, I.
Yamamoto, H.
Yan, Z.
Yoshida, S.
Zanolin, M.
Zhang, J.
Zhang, L.
Zhao, C.
Zotov, N.
Zucker, M.
Zweizig, J.
Barthelmy, S.
Gehrels, N.
Hurley, K. C.
Palmer, D.
CA LIGO Sci Collaboration
TI Search for Gravitational-Wave Bursts from Soft Gamma Repeaters
SO PHYSICAL REVIEW LETTERS
LA English
DT Article
ID MAGNETIZED NEUTRON-STARS; RAY REPEATERS; FLARE; SGR-1806-20
AB We present a LIGO search for short-duration gravitational waves (GWs) associated with soft gamma ray repeater (SGR) bursts. This is the first search sensitive to neutron star f modes, usually considered the most efficient GW emitting modes. We find no evidence of GWs associated with any SGR burst in a sample consisting of the 27 Dec. 2004 giant flare from SGR 1806-20 and 190 lesser events from SGR 1806-20 and SGR 1900+14. The unprecedented sensitivity of the detectors allows us to set the most stringent limits on transient GW amplitudes published to date. We find upper limit estimates on the model-dependent isotropic GW emission energies (at a nominal distance of 10 kpc) between 3x10(45) and 9x10(52) erg depending on waveform type, detector antenna factors and noise characteristics at the time of the burst. These upper limits are within the theoretically predicted range of some SGR models.
C1 [Abbott, B.; Abbott, R.; Adhikari, R.; Anderson, S. B.; Araya, M.; Armandula, H.; Ballmer, S.; Barish, B. C.; Betzwieser, J.; Billingsley, G.; Black, E.; Blackburn, K.; Bork, R.; Boschi, V.; Brooks, A.; Cannon, K.; Cardenas, L.; Cepeda, C.; Chatterji, S.; Coyne, D.; DeSalvo, R.; Dupuis, R. J.; Echols, C.; Ehrens, P.; Espinoza, E.; Etzel, T.; Fazi, D.; Fricke, T.; Goggin, L.; Gustafson, E. K.; Heefner, J.; Ivanov, A.; Kells, W.; Keppel, D. G.; King, P.; Kondrashov, V.; Kozak, D.; Lazzarini, A.; Lei, M.; Libbrecht, K.; Lindquist, P.; Mageswaran, M.; Mailand, K.; Maros, E.; Marx, J. N.; McIntyre, G.; Meshkov, S.; Meyers, D.; Miller, J.; Miyakawa, O.; Nash, T.; Ogin, G.; Patel, P.; Pedraza, M.; Robertson, N. A.; Russell, P.; Samidi, M.; Sannibale, V.; Sears, B.; Sengupta, A. S.; Smith, M. R.; Stochino, A.; Taylor, R.; Tyler, W.; Vass, S.; Villar, A.; Waldman, S. J.; Wallace, L.; Ward, R.; Weinstein, A.; Whitcomb, S. E.; Willems, P. A.; Yamamoto, H.; Zhang, L.; Zweizig, J.] CALTECH, LIGO, Pasadena, CA 91125 USA.
[Ajith, P.; Allen, B.; Aulbert, C.; Brinkmann, M.; Burmeister, O.; Danzmann, K.; Fehrmann, H.; Gossler, S.; Grote, H.; Harms, J.; Hewitson, M.; Lueck, H.; Machenschalk, B.; Messenger, C. J.; Mossavi, K.; Mueller-Ebhardt, H.; Pletsch, H. J.; Prix, R.; Rainer, N.; Rehbein, H.; Ruediger, A.; Schilling, R.; Schnabel, R.; Somiya, K.; Weinert, M.; Willke, B.; Winkler, W.] Max Planck Inst Gravitat Phys, Albert Einstein Inst, D-30167 Hannover, Germany.
[Summerscales, T. Z.] Andrews Univ, Berrien Springs, MI 49104 USA.
[Dickson, J.; Gray, M.; Lam, P. K.; McClelland, D. E.; McKenzie, K.; MowLowry, C.; Rabeling, D. S.; Scott, S. M.; Searle, A. C.; Wette, K.] Australian Natl Univ, Canberra, ACT 0200, Australia.
[Chen, Y.; Savov, P.] CALTECH, CaRT, Pasadena, CA 91125 USA.
[Cokelaer, T.; Davies, G.; Dietz, A.; Fairhurst, S.; Jones, G.; McKechan, D.; Robinson, C.; Sathyaprakash, B. S.; Schutz, B. F.; Van Den Broeck, C.] Cardi Univ, Cardiff CF24 3AA, S Glam, Wales.
[Bantilan, H.; Christensen, N.] Carleton Coll, Northfield, MN 55057 USA.
[Charlton, P.] Charles Sturt Univ, Wagga Wagga, NSW 2678, Australia.
[Aso, Y.; Bartos, I.; Dwyer, J. G.; Kalmus, P.; Kamat, S.; Khan, R.; Marka, S.; Marka, Z.; Matone, L.; Rollins, J.] Columbia Univ, New York, NY 10027 USA.
[Gretarsson, A. M.; Zanolin, M.] Embry Riddle Aeronaut Univ, Prescott, AZ 86301 USA.
[Penn, S.] Hobart & William Smith Coll, Geneva, NY 14456 USA.
[Khazanov, E.; Kozhevatov, I.] Russian Acad Sci, Inst Appl Phys, Nizhnii Novgorod 603950, Russia.
[Dhurandhar, S.; Mitra, S.; Mukhopadhyay, H.] Inter Univ, Ctr Astron & Astrophys, Pune 411007, Maharashtra, India.
[Aufmuth, P.; Danzmann, K.; Hage, B.; Kwee, P.; Lueck, H.; Meier, T.; Thuering, A.; Vahlbruch, H.; Willke, B.] Leibniz Univ Hannover, D-30167 Hannover, Germany.
[Bayer, K.; Blackburn, L.; Bodiya, T. P.; Brunet, G.; Cao, J.; Corbitt, T.; Donovan, F.; Duke, I.; Fritschel, P.; Goda, K.; Grimaldi, F.; Harry, G.; Katsavounidis, E.; MacInnis, M.; Markowitz, J.; Mason, K.; Mavalvala, N.; Mittleman, R.; Ottaway, D. J.; Ruet, L.; Sarin, P.; Shoemaker, D. H.; Smith, N. D.; Stein, L. C.; Weiss, R.; Wipf, C. C.; Zucker, M.] MIT, LIGO, Cambridge, MA 02139 USA.
[Barker, C.; Barker, D.; Bland, B.; Cook, D.; Effler, A.; Garofoli, J.; Gray, C.; Guenther, M.; Ingram, D.; Johnson, B.; Kawabe, K.; Landry, M.; Lubinski, M.; McCarthy, R.; Mendell, G.; Moreno, G.; Myers, E.; Myers, J.; Parameshwaraiah, V.; Raab, F.; Radkins, H.; Rivera, B.; Ryan, K.; Sandberg, V.; Savage, R.; Schwinberg, P.; Sigg, D.; Vorvick, C.; Wilkinson, C.; Worden, J.] LIGO Hanford Observ, Richland, WA 99352 USA.
[Bogue, L.; Evans, T.; Frolov, V. V.; Fyffe, M.; Giaime, J. A.; Giardina, K. D.; Hanson, J.; Hoak, D.; Lormand, M.; O'Reilly, B.; Overmier, H.; Riesen, R.; Roddy, S.; Romie, J.; Sellers, D.; Sibley, A.; Stuver, A.; Thacker, J.; Torres, C.; Traylor, G.; Wooley, R.; Yakushin, I.] LIGO Livingston Observ, Livingston, LA 70754 USA.
[Amin, R.; Giaime, J. A.; Gonzalez, G.; Gouaty, R.; Hanna, C.; Johnson, W. W.; Kissel, J. S.; Matichard, F.; Rodriguez, A.; Slutsky, J.; Sung, M.; Wen, S.] Louisiana State Univ, Baton Rouge, LA 70803 USA.
[Zotov, N.] Louisiana Tech Univ, Ruston, LA 71272 USA.
[McHugh, M.] Loyola Univ, New Orleans, LA 70118 USA.
[Bilenko, I. A.; Braginsky, V. B.; Khalili, F. Ya.; Mitrofanov, V. P.; Vyachanin, S. P.] Moscow MV Lomonosov State Univ, Moscow 119992, Russia.
[Camp, J. B.; Cannizzo, J.; Numata, K.; Barthelmy, S.; Gehrels, N.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
[Kawamura, S.; Kawazoe, F.; Kokeyama, K.; Leonhardt, V.; Nishizawa, A.; Sakata, S.; Sato, S.] Natl Astron Observ, Tokyo 1818588, Japan.
[Kalogera, V.; Kim, C.; van der Sluys, M.] Northwestern Univ, Evanston, IL 60208 USA.
[Greenhalgh, R. J. S.; Hayler, T.; O'Dell, J.; Wilmut, I.] Rutherford Appleton Lab, Didcot OX11 0QX, Oxon, England.
[Beyersdorf, P. T.] San Jose State Univ, San Jose, CA 95192 USA.
[Saraf, S.] Sonoma State Univ, Rohnert Pk, CA 94928 USA.
[Rakhmanov, M.; Yoshida, S.] SE Louisiana Univ, Hammond, LA 70402 USA.
[Doomes, E. E.; McGuire, S. C.] Southern Univ, Baton Rouge, LA 70813 USA.
[Doomes, E. E.; McGuire, S. C.] A&M Coll, Baton Rouge, LA 70813 USA.
[Allen, G.; Bullington, A.; Byer, R. L.; Casebolt, T.; Clark, D.; DeBra, D.; Degree, M.; Fejer, M. M.; Hennessy, M.; Lantz, B.; Leindecker, N.; Lu, P.; Markosyan, A.; Route, R.; Sinha, S.; Sun, K. -X.; Ulmen, J.; Urbanek, K.] Stanford Univ, Stanford, CA 94305 USA.
[Brown, D. A.; Dalrymple, J.; Hirose, E.; Saulson, P. R.; Smith, J. R.] Syracuse Univ, Syracuse, NY 13244 USA.
[Desai, S.; Finn, L. S.; Kopparapu, R. K.; Lang, M. M.; Minelli, J.; O'Shaughnessy, R.; Owen, B. J.; Petrie, T.; Ramsunder, M.; Thorne, K. A.; Williams, H. R.] Penn State Univ, University Pk, PA 16802 USA.
[Matzner, R.; McIvor, G.] Univ Texas Austin, Austin, TX 78712 USA.
[Diaz, M.; Grosso, R.; Hayama, K.; Mohanty, S.; Mukherjee, S.; Romano, J. D.; Stone, R.] Univ Texas Brownsville & Texas Southmost Coll, Brownsville, TX 78520 USA.
[Ugolini, D.] Trinity Univ, San Antonio, TX 78212 USA.
[Sancho de la Jordana, L.; Sintes, A. M.; Trias, M.] Univ Illes Balears, E-07122 Palma de Mallorca, Spain.
[Hosken, D.; Munch, J.; Veitch, P.] Univ Adelaide, Adelaide, SA 5005, Australia.
[Aston, S.; Chelkowski, S.; Cutler, R. M.; Freise, A.; Hallam, J. M.; Hild, S.; Kasprzyk, D.; Lodhia, D.; Perreca, A.; Robinson, E. L.; Vecchio, A.; Veitch, J.] Univ Birmingham, Birmingham B15 2TT, W Midlands, England.
[Arain, M. A.; Dooley, K. L.; Klimenko, S.; Lin, H.; Lucianetti, A.; Martin, R. M.; Mercer, R. A.; Mitselmakher, G.; Mueller, G.; Ottens, R. S.; Pankow, C.; Quetschke, V.; Reitze, D. H.; Tanner, D. B.; Whiting, B. F.; Williams, L.; Wu, W.] Univ Florida, Gainesville, FL 32611 USA.
[Barr, B.; Barton, M. A.; Bastarrika, M.; Cagnoli, G.; Chalkley, E.; Clark, J.; Cumming, A.; Cunningham, L.; Grant, A.; Heng, I. S.; Heptonstall, A.; Hough, J.; Huttner, S. H.; Jones, R.; Martin, I.; Miller, J.; Murray, P.; Nelson, J.; Newton, G.; Pitkin, M.; Plissi, M. V.; Reid, S.; Robertson, N. A.; Rowan, S.; Sorazu, B.; Strain, K. A.; Taylor, R.; Tokmakov, K. V.; Torrie, C.; Ward, H.; Woan, G.] Univ Glasgow, Glasgow G12 8QQ, Lanark, Scotland.
[Buonanno, A.; Kanner, J.; Pan, Y.; Shawhan, P.] Univ Maryland, College Pk, MD 20742 USA.
[Cadonati, L.] Univ Massachusetts, Amherst, MA 01003 USA.
[Dergachev, V.; Goetz, E.; Gustafson, R.; Riles, K.; Zhang, J.] Univ Michigan, Ann Arbor, MI 48109 USA.
[Mandic, V.] Univ Minnesota, Minneapolis, MN 55455 USA.
[Brau, J. E.; Frey, R.; Harstad, E.; Ito, M.; Leonor, I.; Schofield, R.; Strom, D. M.] Univ Oregon, Eugene, OR 97403 USA.
[Fricke, T.; Giampanis, S.; Melissinos, A.] Univ Rochester, Rochester, NY 14627 USA.
[Conte, R.; Postiglione, F.] Univ Salerno, I-84084 Salerno, Italy.
[Castaldi, G.; Pinto, I. M.; Principe, M.] Univ Sannio Benevento, I-82100 Benevento, Italy.
[Jones, D. I.] Univ Southampton, Southampton SO17 1BJ, Hants, England.
[Lockerbie, N. A.] Univ Strathclyde, Glasgow G1 1XQ, Lanark, Scotland.
[Barriga, P.; Blair, D.; Dumas, J. -C.; Fan, Y.; Gras, S.; Ju, L.; Schediwy, S. W.; Yan, Z.; Zhao, C.] Univ Western Australia, Crawley, WA 6009, Australia.
[Allen, B.; Anderson, W. G.; Armor, P.; Biswas, R.; Brady, P. R.; Creighton, J. D. E.; Flasch, K.; Fotopoulos, N.; Hammer, D.; Moe, B.; Papa, M. A.; Siemens, X.; Vaulin, R.; Wiseman, A. G.] Univ Wisconsin, Milwaukee, WI 53201 USA.
[Bose, S.; Rogan, A. M.] Washington State Univ, Pullman, WA 99164 USA.
[Hurley, K. C.] Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA.
[Palmer, D.] Los Alamos Natl Lab, Los Alamos, NM 87545 USA.
[Babak, S.; Chen, Y.; Degallaix, J.; Gholami, I.; Grunewald, S.; Krishnan, B.; Papa, M. A.; Schutz, B. F.; Sintes, A. M.; Somiya, K.; Takahashi, H.; Whelan, J. T.] Max Planck Inst Gravitat Phys, Albert Einstein Inst, D-14476 Golm, Germany.
RP Abbott, B (reprint author), CALTECH, LIGO, Pasadena, CA 91125 USA.
RI Sigg, Daniel/I-4308-2015; Pinto, Innocenzo/L-3520-2016; Harms,
Jan/J-4359-2012; Bartos, Imre/A-2592-2017; Frey, Raymond/E-2830-2016;
Ward, Robert/I-8032-2014; Schutz, Bernard/B-1504-2010; Vyatchanin,
Sergey/J-2238-2012; Khazanov, Efim/B-6643-2014; Lucianetti,
Antonio/G-7383-2014; Khalili, Farit/D-8113-2012; Vecchio,
Alberto/F-8310-2015; Mow-Lowry, Conor/F-8843-2015; Khan,
Rubab/F-9455-2015; Ottaway, David/J-5908-2015; Postiglione,
Fabio/O-4744-2015; Mitrofanov, Valery/D-8501-2012; Bilenko,
Igor/D-5172-2012; Allen, Bruce/K-2327-2012; Chen, Yanbei/A-2604-2013;
Barker, David/A-5671-2013; Fricke, Thomas/B-6885-2013; Zhao,
Chunnong/C-2403-2013; Ju, Li/C-2623-2013; Pitkin, Matthew/I-3802-2013;
Martin, Iain/A-2445-2010; Lam, Ping Koy/A-5276-2008; Freise,
Andreas/F-8892-2011; McClelland, David/E-6765-2010; Kawabe,
Keita/G-9840-2011; Finn, Lee Samuel/A-3452-2009; Barthelmy,
Scott/D-2943-2012; Hild, Stefan/A-3864-2010; Rowan, Sheila/E-3032-2010;
Strain, Kenneth/D-5236-2011; Raab, Frederick/E-2222-2011; Lueck,
Harald/F-7100-2011; Kawazoe, Fumiko/F-7700-2011; Gehrels,
Neil/D-2971-2012
OI Aulbert, Carsten/0000-0002-1481-8319; Freise,
Andreas/0000-0001-6586-9901; Whiting, Bernard F/0000-0002-8501-8669;
Veitch, John/0000-0002-6508-0713; Principe, Maria/0000-0002-6327-0628;
Papa, M.Alessandra/0000-0002-1007-5298; Kanner,
Jonah/0000-0001-8115-0577; Matichard, Fabrice/0000-0001-8982-8418;
Pinto, Innocenzo M./0000-0002-2679-4457; Minelli,
Jeff/0000-0002-5330-912X; Sorazu, Borja/0000-0002-6178-3198; Hallam,
Jonathan Mark/0000-0002-7087-0461; Nishizawa,
Atsushi/0000-0003-3562-0990; Zweizig, John/0000-0002-1521-3397;
O'Shaughnessy, Richard/0000-0001-5832-8517; Sigg,
Daniel/0000-0003-4606-6526; Frey, Raymond/0000-0003-0341-2636; Stein,
Leo/0000-0001-7559-9597; Cokelaer, Thomas/0000-0001-6286-1138; Ward,
Robert/0000-0001-5503-5241; Whelan, John/0000-0001-5710-6576; Fairhurst,
Stephen/0000-0001-8480-1961; Boschi, Valerio/0000-0001-8665-2293;
Vecchio, Alberto/0000-0002-6254-1617; Khan, Rubab/0000-0001-5100-5168;
Postiglione, Fabio/0000-0003-0628-3796; Allen,
Bruce/0000-0003-4285-6256; Zhao, Chunnong/0000-0001-5825-2401; Pitkin,
Matthew/0000-0003-4548-526X; Lam, Ping Koy/0000-0002-4421-601X;
McClelland, David/0000-0001-6210-5842; Finn, Lee
Samuel/0000-0002-3937-0688; Strain, Kenneth/0000-0002-2066-5355; Lueck,
Harald/0000-0001-9350-4846;
FU Australian Research Council; Council of Scientific and Industrial
Research of India; Istituto Nazionale di Fisica Nucleare of Italy;
Spanish Ministerio de Educacion y Ciencia; Conselleria d'Economia
Hisenda i Innovacio of the Govern de les Illes Balears; Royal Society;
Scottish Funding Council; Scottish Universities Physics Alliance;
National Aeronautics and Space Administration; Carnegie Trust;
Leverhulme Trust; David and Lucile Packard Foundation; Research
Corporation; Alfred P. Sloan Foundation; JPL [1282043, 1268385]; NASA
[NAG5-11451, NNG04GM50G]
FX The authors are grateful to the Konus-Wind team and to S. Mereghetti for
information used in the S5 burst list, and to G. Lichti and D. Smith for
information on the giant flare event time. The authors gratefully
acknowledge the support of the United States National Science Foundation
for the construction and operation of the LIGO Laboratory and the
Science and Technology Facilities Council of the United Kingdom, the
Max-Planck-Society, and the State of Niedersachsen/ Germany for support
of the construction and operation of the GEO600 detector. The authors
also gratefully acknowledge the support of the research by these
agencies and by the Australian Research Council, the Council of
Scientific and Industrial Research of India, the Istituto Nazionale di
Fisica Nucleare of Italy, the Spanish Ministerio de Educacion y Ciencia,
the Conselleria d'Economia Hisenda i Innovacio of the Govern de les
Illes Balears, the Royal Society, the Scottish Funding Council, the
Scottish Universities Physics Alliance, The National Aeronautics and
Space Administration, the Carnegie Trust, the Leverhulme Trust, the
David and Lucile Packard Foundation, the Research Corporation, and the
Alfred P. Sloan Foundation. K. C. H. is grateful for support under JPL
contracts 1282043 and 1268385, and NASA grants NAG5-11451 and
NNG04GM50G.
NR 39
TC 58
Z9 58
U1 2
U2 12
PU AMER PHYSICAL SOC
PI COLLEGE PK
PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA
SN 0031-9007
J9 PHYS REV LETT
JI Phys. Rev. Lett.
PD NOV 21
PY 2008
VL 101
IS 21
AR 211102
DI 10.1103/PhysRevLett.101.211102
PG 6
WC Physics, Multidisciplinary
SC Physics
GA 375VI
UT WOS:000261141500009
PM 19113401
ER
PT J
AU Abdo, AA
Ackermann, M
Atwood, WB
Baldini, L
Ballet, J
Barbiellini, G
Baring, MG
Bastieri, D
Baughman, BM
Bechtol, K
Bellazzini, R
Berenji, B
Blandford, RD
Bloom, ED
Bogaert, G
Bonamente, E
Borgland, AW
Bregeon, J
Brez, A
Brigida, M
Bruel, P
Burnett, TH
Caliandro, GA
Cameron, RA
Caraveo, PA
Carlson, P
Casandjian, JM
Cecchi, C
Charles, E
Chekhtman, A
Cheung, CC
Chiang, J
Ciprini, S
Claus, R
Cohen-Tanugi, J
Cominsky, LR
Conrad, J
Cutini, S
Davis, DS
Dermer, CD
de Angelis, A
de Palma, F
Digel, SW
Dormody, M
Silva, EDE
Drell, PS
Dubois, R
Dumora, D
Edmonds, Y
Farnier, C
Focke, WB
Fukazawa, Y
Funk, S
Fusco, P
Gargano, F
Gasparrini, D
Gehrels, N
Germani, S
Giebels, B
Giglietto, N
Giordano, F
Glanzman, T
Godfrey, G
Grenier, IA
Grondin, MH
Grove, JE
Guillemot, L
Guiriec, S
Harding, AK
Hartman, RC
Hays, E
Hughes, RE
Johannesson, G
Johnson, AS
Johnson, RP
Johnson, TJ
Johnson, WN
Kamae, T
Kanai, Y
Kanbach, G
Katagiri, H
Kawai, N
Kerr, M
Kishishita, T
Kiziltan, B
Knodlseder, J
Kocian, ML
Komin, N
Kuehn, F
Kuss, M
Latronico, L
Lemoine-Goumard, M
Longo, F
Lonjou, V
Loparco, F
Lott, B
Lovellette, MN
Lubrano, P
Makeev, A
Marelli, M
Mazziotta, MN
McEnery, JE
McGlynn, S
Meurer, C
Michelson, PF
Mineo, T
Mitthumsiri, W
Mizuno, T
Moiseev, AA
Monte, C
Monzani, ME
Morselli, A
Moskalenko, IV
Murgia, S
Nakamori, T
Nolan, PL
Nuss, E
Ohno, M
Ohsugi, T
Okumura, A
Omodei, N
Orlando, E
Ormes, JF
Ozaki, M
Paneque, D
Panetta, JH
Parent, D
Pelassa, V
Pepe, M
Pesce-Rollins, M
Piano, G
Pieri, L
Piron, F
Porter, TA
Raino, S
Rando, R
Ray, PS
Razzano, M
Reimer, A
Reimer, O
Reposeur, T
Ritz, S
Rochester, LS
Rodriguez, AY
Romani, RW
Roth, M
Ryde, F
Sadrozinski, HFW
Sanchez, D
Sander, A
Parkinson, PMS
Schalk, TL
Sellerholm, A
Sgro, C
Siskind, EJ
Smith, DA
Smith, PD
Spandre, G
Spinelli, P
Starck, JL
Strickman, MS
Suson, DJ
Tajima, H
Takahashi, H
Takahashi, T
Tanaka, T
Thayer, JB
Thayer, JG
Thompson, DJ
Thorsett, SE
Tibaldo, L
Torres, DF
Tosti, G
Tramacere, A
Usher, TL
Van Etten, A
Vilchez, N
Vitale, V
Wang, P
Watters, K
Winer, BL
Wood, KS
Yasuda, H
Ylinen, T
Ziegler, M
AF Abdo, A. A.
Ackermann, M.
Atwood, W. B.
Baldini, L.
Ballet, J.
Barbiellini, G.
Baring, M. G.
Bastieri, D.
Baughman, B. M.
Bechtol, K.
Bellazzini, R.
Berenji, B.
Blandford, R. D.
Bloom, E. D.
Bogaert, G.
Bonamente, E.
Borgland, A. W.
Bregeon, J.
Brez, A.
Brigida, M.
Bruel, P.
Burnett, T. H.
Caliandro, G. A.
Cameron, R. A.
Caraveo, P. A.
Carlson, P.
Casandjian, J. M.
Cecchi, C.
Charles, E.
Chekhtman, A.
Cheung, C. C.
Chiang, J.
Ciprini, S.
Claus, R.
Cohen-Tanugi, J.
Cominsky, L. R.
Conrad, J.
Cutini, S.
Davis, D. S.
Dermer, C. D.
de Angelis, A.
de Palma, F.
Digel, S. W.
Dormody, M.
do Couto e Silva, E.
Drell, P. S.
Dubois, R.
Dumora, D.
Edmonds, Y.
Farnier, C.
Focke, W. B.
Fukazawa, Y.
Funk, S.
Fusco, P.
Gargano, F.
Gasparrini, D.
Gehrels, N.
Germani, S.
Giebels, B.
Giglietto, N.
Giordano, F.
Glanzman, T.
Godfrey, G.
Grenier, I. A.
Grondin, M. -H.
Grove, J. E.
Guillemot, L.
Guiriec, S.
Harding, A. K.
Hartman, R. C.
Hays, E.
Hughes, R. E.
Johannesson, G.
Johnson, A. S.
Johnson, R. P.
Johnson, T. J.
Johnson, W. N.
Kamae, T.
Kanai, Y.
Kanbach, G.
Katagiri, H.
Kawai, N.
Kerr, M.
Kishishita, T.
Kiziltan, B.
Knodlseder, J.
Kocian, M. L.
Komin, N.
Kuehn, F.
Kuss, M.
Latronico, L.
Lemoine-Goumard, M.
Longo, F.
Lonjou, V.
Loparco, F.
Lott, B.
Lovellette, M. N.
Lubrano, P.
Makeev, A.
Marelli, M.
Mazziotta, M. N.
McEnery, J. E.
McGlynn, S.
Meurer, C.
Michelson, P. F.
Mineo, T.
Mitthumsiri, W.
Mizuno, T.
Moiseev, A. A.
Monte, C.
Monzani, M. E.
Morselli, A.
Moskalenko, I. V.
Murgia, S.
Nakamori, T.
Nolan, P. L.
Nuss, E.
Ohno, M.
Ohsugi, T.
Okumura, A.
Omodei, N.
Orlando, E.
Ormes, J. F.
Ozaki, M.
Paneque, D.
Panetta, J. H.
Parent, D.
Pelassa, V.
Pepe, M.
Pesce-Rollins, M.
Piano, G.
Pieri, L.
Piron, F.
Porter, T. A.
Raino, S.
Rando, R.
Ray, P. S.
Razzano, M.
Reimer, A.
Reimer, O.
Reposeur, T.
Ritz, S.
Rochester, L. S.
Rodriguez, A. Y.
Romani, R. W.
Roth, M.
Ryde, F.
Sadrozinski, H. F. -W.
Sanchez, D.
Sander, A.
Parkinson, P. M. Saz
Schalk, T. L.
Sellerholm, A.
Sgro, C.
Siskind, E. J.
Smith, D. A.
Smith, P. D.
Spandre, G.
Spinelli, P.
Starck, J. -L.
Strickman, M. S.
Suson, D. J.
Tajima, H.
Takahashi, H.
Takahashi, T.
Tanaka, T.
Thayer, J. B.
Thayer, J. G.
Thompson, D. J.
Thorsett, S. E.
Tibaldo, L.
Torres, D. F.
Tosti, G.
Tramacere, A.
Usher, T. L.
Van Etten, A.
Vilchez, N.
Vitale, V.
Wang, P.
Watters, K.
Winer, B. L.
Wood, K. S.
Yasuda, H.
Ylinen, T.
Ziegler, M.
TI The Fermi Gamma-Ray Space Telescope Discovers the Pulsar in the Young
Galactic Supernova Remnant CTA 1
SO SCIENCE
LA English
DT Article
ID X-RAY; EMISSION; RADIO; RADIATION
AB Energetic young pulsars and expanding blast waves [ supernova remnants (SNRs)] are the most visible remains after massive stars, ending their lives, explode in core-collapse supernovae. The Fermi Gamma- Ray Space Telescope has unveiled a radio quiet pulsar located near the center of the compact synchrotron nebula inside the supernova remnant CTA 1. The pulsar, discovered through its gamma- ray pulsations, has a period of 316.86 milliseconds and a period derivative of 3.614 x 10(-13) seconds per second. Its characteristic age of 10(4) years is comparable to that estimated for the SNR. We speculate that most unidentified Galactic gamma- ray sources associated with star- forming regions and SNRs are such young pulsars.
C1 [Kanbach, G.; Orlando, E.] Max Planck Inst Extraterr Phys, D-85748 Garching, Germany.
[Kawai, N.] RIKEN, Inst Phys & Chem Res, Cosm Radiat Lab, Wako, Saitama 3510198, Japan.
[Kishishita, T.; Ohno, M.; Ozaki, M.; Takahashi, T.] Japan Aerosp Explorat Agcy, Inst Space & Astronaut Sci, Sagamihara, Kanagawa 2298510, Japan.
[Kiziltan, B.] Univ Calif Santa Cruz, Univ Calif Observ, Lick Observ, Santa Cruz, CA 95064 USA.
[Knodlseder, J.; Vilchez, N.] UPS, CNRS, Ctr Etud Spatiale Rayonnements, F-31028 Toulouse 4, France.
[Mineo, T.] Ist Astrofis Spaziale & Fis Cosmica Palermo, I-90146 Palermo, Italy.
[Moiseev, A. A.] NASA, Goddard Space Flight Ctr, Ctr Res & Explorat Space Sci & Technol, Greenbelt, MD 20771 USA.
[Morselli, A.; Piano, G.; Vitale, V.] Ist Nazl Fis Nucl, Sez Roma Tor Vergata, I-00133 Rome, Italy.
[Morselli, A.; Piano, G.; Vitale, V.] Univ Roma Tor Vergata, Dipartimento Fis, I-00133 Rome, Italy.
[Okumura, A.] Univ Tokyo, Dept Phys, Grad Sch Sci, Bunkyo Ku, Tokyo 1130033, Japan.
[Ormes, J. F.] Univ Denver, Dept Phys & Astron, Denver, CO 80208 USA.
[Rodriguez, A. Y.; Torres, D. F.] CSIC, Inst Ciencies Espai, Inst Estud Espacials Catalunya, Barcelona 08193, Spain.
[Siskind, E. J.] NYCB Real Time Comp Inc, Lattingtown, NY 11560 USA.
[Suson, D. J.] Purdue Univ Calumet, Dept Chem & Phys, Hammond, IN 46323 USA.
[Torres, D. F.] Inst Catalana Recerca & Estud Avancats, Barcelona, Spain.
[Tramacere, A.] Consorzio Interuniv Fis Spaziale, I-10133 Turin, Italy.
[Ylinen, T.] Univ Kalmar, Sch Pure & Appl Nat Sci, SE-39182 Kalmar, Sweden.
[Abdo, A. A.] Natl Acad Sci, Natl Res Council, Washington, DC 20001 USA.
[Abdo, A. A.; Chekhtman, A.; Davis, D. S.; Dermer, C. D.; Grove, J. E.; Johnson, W. N.; Lovellette, M. N.; Ray, P. S.; Strickman, M. S.; Wood, K. S.] USN, Res Lab, Div Space Sci, Washington, DC 20375 USA.
[Ackermann, M.; Bechtol, K.; Berenji, B.; Blandford, R. D.; Bloom, E. D.; Borgland, A. W.; Cameron, R. A.; Charles, E.; Chiang, J.; Claus, R.; Digel, S. W.; do Couto e Silva, E.; Drell, P. S.; Dubois, R.; Edmonds, Y.; Focke, W. B.; Funk, S.; Glanzman, T.; Godfrey, G.; Johannesson, G.; Johnson, A. S.; Kamae, T.; Kocian, M. L.; Michelson, P. F.; Mitthumsiri, W.; Monzani, M. E.; Moskalenko, I. V.; Murgia, S.; Nolan, P. L.; Paneque, D.; Panetta, J. H.; Reimer, A.; Reimer, O.; Rochester, L. S.; Romani, R. W.; Tajima, H.; Tanaka, T.; Thayer, J. B.; Thayer, J. G.; Tramacere, A.; Usher, T. L.; Van Etten, A.; Wang, P.; Watters, K.] Stanford Univ, WW Hansen Expt Phys Lab, Kavli Inst Particle Astrophys & Cosmol, Stanford, CA 94305 USA.
[Ackermann, M.; Bechtol, K.; Berenji, B.; Blandford, R. D.; Bloom, E. D.; Borgland, A. W.; Cameron, R. A.; Charles, E.; Chiang, J.; Claus, R.; Digel, S. W.; do Couto e Silva, E.; Drell, P. S.; Dubois, R.; Edmonds, Y.; Focke, W. B.; Funk, S.; Glanzman, T.; Godfrey, G.; Johannesson, G.; Johnson, A. S.; Kamae, T.; Kocian, M. L.; Michelson, P. F.; Mitthumsiri, W.; Monzani, M. E.; Moskalenko, I. V.; Murgia, S.; Nolan, P. L.; Paneque, D.; Panetta, J. H.; Reimer, A.; Reimer, O.; Rochester, L. S.; Romani, R. W.; Tajima, H.; Tanaka, T.; Thayer, J. B.; Thayer, J. G.; Tramacere, A.; Usher, T. L.; Van Etten, A.; Wang, P.; Watters, K.] Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94305 USA.
[Atwood, W. B.; Dormody, M.; Johnson, R. P.; Porter, T. A.; Sadrozinski, H. F. -W.; Parkinson, P. M. Saz; Schalk, T. L.; Thorsett, S. E.; Ziegler, M.] Univ Calif Santa Cruz, Santa Cruz Inst Particle Phys, Dept Phys, Santa Cruz, CA 95064 USA.
[Atwood, W. B.; Dormody, M.; Johnson, R. P.; Porter, T. A.; Sadrozinski, H. F. -W.; Parkinson, P. M. Saz; Schalk, T. L.; Thorsett, S. E.; Ziegler, M.] Univ Calif Santa Cruz, Santa Cruz Inst Particle Phys, Dept Astron, Santa Cruz, CA 95064 USA.
[Baldini, L.; Bellazzini, R.; Bregeon, J.; Brez, A.; Kuss, M.; Latronico, L.; Omodei, N.; Pesce-Rollins, M.; Razzano, M.; Sgro, C.; Spandre, G.] Ist Nazl Fis Nucl, Sez Pisa, I-56127 Pisa, Italy.
[Ballet, J.; Casandjian, J. M.; Grenier, I. A.; Komin, N.; Starck, J. -L.] Univ Paris Diderot, Serv Astrophys, Lab Astrophys Interact Multiechelles, CEA Saclay,CNRS, F-91191 Gif Sur Yvette, France.
[Barbiellini, G.; Longo, F.] Ist Nazl Fis Nucl, Sez Trieste, I-34127 Trieste, Italy.
[Barbiellini, G.; Longo, F.] Univ Trieste, Dipartimento Fis, I-34127 Trieste, Italy.
[Baring, M. G.] Rice Univ, Dept Phys & Astron, Houston, TX 77251 USA.
[Bastieri, D.; Pieri, L.; Rando, R.; Tibaldo, L.] Ist Nazl Fis Nucl, Sez Padova, I-35131 Padua, Italy.
[Bastieri, D.; Rando, R.; Tibaldo, L.] Univ Padua, Dipartimento Fis G Galilei, I-35131 Padua, Italy.
[Baughman, B. M.; Hughes, R. E.; Kuehn, F.; Sander, A.; Smith, P. D.; Winer, B. L.] Ohio State Univ, Dept Phys, Ctr Cosmol & Astroparticle Phys, Columbus, OH 43210 USA.
[Bogaert, G.; Bruel, P.; Giebels, B.; Sanchez, D.] Ecole Polytech, CNRS, Lab Leprince Ringuet, CNRS,IN2P3, F-91128 Palaiseau, France.
[Bonamente, E.; Cecchi, C.; Ciprini, S.; Germani, S.; Lubrano, P.; Pepe, M.; Tosti, G.] Ist Nazl Fis Nucl, Sez Perugia, I-06123 Perugia, Italy.
[Bonamente, E.; Cecchi, C.; Ciprini, S.; Germani, S.; Lubrano, P.; Pepe, M.; Tosti, G.] Univ Perugia, Dipartimento Fis, I-06123 Perugia, Italy.
[Brigida, M.; Caliandro, G. A.; de Palma, F.; Fusco, P.; Giglietto, N.; Giordano, F.; Loparco, F.; Monte, C.; Raino, S.; Spinelli, P.] Univ Politecn Bari, Dipartimento Fis M Merlin, I-70126 Bari, Italy.
[Brigida, M.; Caliandro, G. A.; de Palma, F.; Fusco, P.; Gargano, F.; Giglietto, N.; Giordano, F.; Loparco, F.; Mazziotta, M. N.; Monte, C.; Raino, S.; Spinelli, P.] Ist Nazl Fis Nucl, Sez Bari, I-70126 Bari, Italy.
[Burnett, T. H.; Kerr, M.; Roth, M.] Univ Washington, Dept Phys, Seattle, WA 98195 USA.
[Caraveo, P. A.; Marelli, M.] Ist Astrofis Spaziale & Fis Cosmica, Ist Nazl Astrofis, I-20133 Milan, Italy.
[Carlson, P.; Conrad, J.; McGlynn, S.; Ryde, F.; Ylinen, T.] AlbaNova, Dept Phys, Royal Inst Technol Kungliga Tekn Hogskolan, SE-10691 Stockholm, Sweden.
[Chekhtman, A.; Makeev, A.] George Mason Univ, Fairfax, VA 22030 USA.
[Cheung, C. C.; Gehrels, N.; Harding, A. K.; Hartman, R. C.; Hays, E.; Johnson, T. J.; McEnery, J. E.; Ritz, S.; Thompson, D. J.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
[Cohen-Tanugi, J.; Farnier, C.; Guiriec, S.; Komin, N.; Nuss, E.; Pelassa, V.; Piron, F.] Univ Montpellier 2, Lab Phys Theor & Astroparticules, CNRS IN2P3, Montpellier, France.
[Cominsky, L. R.] Sonoma State Univ, Dept Phys & Astron, Rohnert Pk, CA 94928 USA.
[Conrad, J.; Meurer, C.; Sellerholm, A.] Stockholm Univ, Dept Phys, SE-10691 Stockholm, Sweden.
[Cutini, S.; Gasparrini, D.] Agcy Spaziale Italiana Sci Data Ctr, I-00044 Frascati, Italy.
[Davis, D. S.] Univ Maryland Baltimore Cty, Ctr Space Sci & Technol, Baltimore, MD 21250 USA.
[de Angelis, A.] Univ Udine, Dipartimento Fis, I-33100 Udine, Italy.
[de Angelis, A.] Ist Nazl Fis Nucl, Sez Trieste, Grp Coll Udine, I-33100 Udine, Italy.
[Dumora, D.; Grondin, M. -H.; Guillemot, L.; Lemoine-Goumard, M.; Lonjou, V.; Lott, B.; Parent, D.; Reposeur, T.; Smith, D. A.] CEN Bordeaux Gradignan, CNRS, IN2P3, UMR 5797, F-33175 Gradignan, France.
[Brez, A.; Dumora, D.; Grondin, M. -H.; Guillemot, L.; Lemoine-Goumard, M.; Lonjou, V.; Lott, B.; Parent, D.; Reposeur, T.; Smith, D. A.] Univ Bordeaux 1, CEN Bordeaux Gradignan, UMR 5797, F-33175 Gradignan, France.
[Fukazawa, Y.; Katagiri, H.; Mizuno, T.; Ohsugi, T.; Takahashi, H.; Yasuda, H.] Hiroshima Univ, Dept Phys Sci, Higashihiroshima 7398526, Japan.
[Fukazawa, Y.; Katagiri, H.; Mizuno, T.; Ohsugi, T.; Takahashi, H.; Yasuda, H.] Hiroshima Univ, Hiroshima Astrophys Sci Ctr, Higashihiroshima 7398526, Japan.
[Gehrels, N.; Johnson, T. J.; Ritz, S.] Univ Maryland, College Pk, MD 20742 USA.
[Kanai, Y.; Kawai, N.; Nakamori, T.] Tokyo Inst Technol, Dept Phys, Meguro Ku, Tokyo 1528551, Japan.
RP Kanbach, G (reprint author), Max Planck Inst Extraterr Phys, Giessenbachstr, D-85748 Garching, Germany.
EM gok@mpe.mpg.de; kent.wood@nrl.navy.mil; ziegler@scipp.ucsc.edu
RI Komin, Nukri/J-6781-2015; Ozaki, Masanobu/K-1165-2013; Rando,
Riccardo/M-7179-2013; Hays, Elizabeth/D-3257-2012; Johnson,
Neil/G-3309-2014; Reimer, Olaf/A-3117-2013; Funk, Stefan/B-7629-2015;
Johannesson, Gudlaugur/O-8741-2015; Gargano, Fabio/O-8934-2015; Loparco,
Francesco/O-8847-2015; Moskalenko, Igor/A-1301-2007; Mazziotta, Mario
/O-8867-2015; Sgro, Carmelo/K-3395-2016; Torres, Diego/O-9422-2016;
Orlando, E/R-5594-2016; Nolan, Patrick/A-5582-2009; De Angelis,
Alessandro/B-5372-2009; Starck, Jean-Luc/D-9467-2011; Thompson,
David/D-2939-2012; Harding, Alice/D-3160-2012; Gehrels,
Neil/D-2971-2012; McEnery, Julie/D-6612-2012; Baldini, Luca/E-5396-2012;
lubrano, pasquale/F-7269-2012; Morselli, Aldo/G-6769-2011; Kuss,
Michael/H-8959-2012; giglietto, nicola/I-8951-2012; Tosti,
Gino/E-9976-2013; Saz Parkinson, Pablo Miguel/I-7980-2013
OI Cutini, Sara/0000-0002-1271-2924; Gasparrini, Dario/0000-0002-5064-9495;
Tramacere, Andrea/0000-0002-8186-3793; Baldini,
Luca/0000-0002-9785-7726; Ray, Paul/0000-0002-5297-5278; Sgro',
Carmelo/0000-0001-5676-6214; Thorsett, Stephen/0000-0002-2025-9613;
SPINELLI, Paolo/0000-0001-6688-8864; De Angelis,
Alessandro/0000-0002-3288-2517; Caraveo, Patrizia/0000-0003-2478-8018;
Komin, Nukri/0000-0003-3280-0582; Mineo, Teresa/0000-0002-4931-8445;
Bastieri, Denis/0000-0002-6954-8862; Omodei, Nicola/0000-0002-5448-7577;
Pesce-Rollins, Melissa/0000-0003-1790-8018; Reimer,
Olaf/0000-0001-6953-1385; Funk, Stefan/0000-0002-2012-0080; Johannesson,
Gudlaugur/0000-0003-1458-7036; Gargano, Fabio/0000-0002-5055-6395;
Loparco, Francesco/0000-0002-1173-5673; Moskalenko,
Igor/0000-0001-6141-458X; Mazziotta, Mario /0000-0001-9325-4672; Torres,
Diego/0000-0002-1522-9065; Starck, Jean-Luc/0000-0003-2177-7794;
Thompson, David/0000-0001-5217-9135; lubrano,
pasquale/0000-0003-0221-4806; Morselli, Aldo/0000-0002-7704-9553;
giglietto, nicola/0000-0002-9021-2888;
FU NASA; U. S. Department of Energy in the United States; Commissariat
l'Energie Atomique; Centre National de la Recherche
Scientifique/Institut National de Physique Nuclaire et de Physique des
Particules in France; Agenzia Spaziale Italiana; Istituto Nazionale di
Fisica Nucleare in Italy; Ministry of Education, Culture, Sports,
Science and Technology, the High Energy Accelerator Research
Organization,; JAXA in Japan; K.A. Wallenberg Foundation; Swedish
National Space Board in Sweden
FX The Fermi LAT Collaboration acknowledges the generous support of a
number of agencies and institutes, including NASA and the U. S.
Department of Energy in the United States; the Commissariat l'Energie
Atomique and the Centre National de la Recherche Scientifique/Institut
National de Physique Nuclaire et de Physique des Particules in France;
the Agenzia Spaziale Italiana and the Istituto Nazionale di Fisica
Nucleare in Italy; the Ministry of Education, Culture, Sports, Science
and Technology, the High Energy Accelerator Research Organization, and
JAXA in Japan, and the K.A. Wallenberg Foundation and the Swedish
National Space Board in Sweden.
NR 28
TC 74
Z9 74
U1 0
U2 3
PU AMER ASSOC ADVANCEMENT SCIENCE
PI WASHINGTON
PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA
SN 0036-8075
EI 1095-9203
J9 SCIENCE
JI Science
PD NOV 21
PY 2008
VL 322
IS 5905
BP 1218
EP 1221
DI 10.1126/science.1165572
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA 374HC
UT WOS:000261033400033
PM 18927355
ER
PT J
AU Holt, JW
Safaeinili, A
Plaut, JJ
Head, JW
Phillips, RJ
Seu, R
Kempf, SD
Choudhary, P
Young, DA
Putzig, NE
Biccari, D
Gim, Y
AF Holt, John W.
Safaeinili, Ali
Plaut, Jeffrey J.
Head, James W.
Phillips, Roger J.
Seu, Roberto
Kempf, Scott D.
Choudhary, Prateek
Young, Duncan A.
Putzig, Nathaniel E.
Biccari, Daniela
Gim, Yonggyu
TI Radar Sounding Evidence for Buried Glaciers in the Southern
Mid-Latitudes of Mars
SO SCIENCE
LA English
DT Article
ID POLAR LAYERED DEPOSITS; LOBATE DEBRIS APRONS; CLIMATE-CHANGE; ICE;
SUBSURFACE; OBLIQUITY; ACCUMULATION; REGION; FLOW
AB Lobate features abutting massifs and escarpments in the middle latitudes of Mars have been recognized in images for decades, but their true nature has been controversial, with hypotheses of origin such as ice- lubricated debris flows or glaciers covered by a layer of surface debris. These models imply an ice content ranging from minor and interstitial to massive and relatively pure. Soundings of these deposits in the eastern Hellas region by the Shallow Radar on the Mars Reconnaissance Orbiter reveal radar properties entirely consistent with massive water ice, supporting the debris- covered glacier hypothesis. The results imply that these glaciers formed in a previous climate conducive to glaciation at middle latitudes. Such features may collectively represent the most extensive nonpolar ice yet recognized on Mars.
C1 [Holt, John W.; Kempf, Scott D.; Choudhary, Prateek; Young, Duncan A.] Univ Texas Austin, Inst Geophys, Jackson Sch Geosci, Austin, TX 78758 USA.
[Safaeinili, Ali; Plaut, Jeffrey J.; Gim, Yonggyu] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[Head, James W.] Brown Univ, Dept Geol Sci, Providence, RI 02912 USA.
[Phillips, Roger J.; Putzig, Nathaniel E.] SW Res Inst, Boulder, CO 80302 USA.
[Seu, Roberto; Biccari, Daniela] Univ Roma La Sapienza, INFOCOM Dept, I-00184 Rome, Italy.
RP Holt, JW (reprint author), Univ Texas Austin, Inst Geophys, Jackson Sch Geosci, Austin, TX 78758 USA.
EM jack@ig.utexas.edu
RI Holt, John/C-4896-2009; Young, Duncan/G-6256-2010
OI Young, Duncan/0000-0002-6866-8176
FU Institute for Geophysics of the Jackson School of Geosciences and NASA
[NAG5-12693]
FX We thank F. Russo, M. Cutigni, O. Fuga, and E. Giacomoni of the SHARAD
Operations Center for their role in acquiring the data over these
targets; F. Bernardini for his assistance in the U. S. data processing
effort; and two anonymous reviewers for their comments and suggestions.
Work at the University of Texas was supported by the Institute for
Geophysics of the Jackson School of Geosciences and NASA grant
NAG5-12693 (J.W.H.). MRO is operated for NASA by Caltech's Jet
Propulsion Laboratory. SHARAD was provided to MRO by the Italian Space
Agency through a contract with Thales Alenia Space Italia and is
operated by the INFOCOM Department, University of Rome. This is UTIG
contribution 2006.
NR 30
TC 138
Z9 139
U1 3
U2 25
PU AMER ASSOC ADVANCEMENT SCIENCE
PI WASHINGTON
PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA
SN 0036-8075
EI 1095-9203
J9 SCIENCE
JI Science
PD NOV 21
PY 2008
VL 322
IS 5905
BP 1235
EP 1238
DI 10.1126/science.1164246
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA 374HC
UT WOS:000261033400038
PM 19023078
ER
PT J
AU Cheung, R
Li, KF
Wang, SH
Pongetti, TJ
Cageao, RP
Sander, SP
Yung, YL
AF Cheung, Ross
Li, King Fai
Wang, Shuhui
Pongetti, Thomas J.
Cageao, Richard P.
Sander, Stanley P.
Yung, Yuk L.
TI Atmospheric hydroxyl radical (OH) abundances from ground-based
ultraviolet solar spectra: an improved retrieval method
SO APPLIED OPTICS
LA English
DT Article
ID LASER-INDUCED FLUORESCENCE; IN-SITU DETECTION; VERTICAL COLUMN
ABUNDANCE; TABLE MOUNTAIN FACILITY; MIDDLE ATMOSPHERE; STRATOSPHERIC OH;
DOPPLER DETECTION; TROPOSPHERIC OH; FRITZ PEAK; SPECTROMETER
AB The Fourier Transform Ultraviolet Spectrometer (FTUVS) instrument has recorded a long-term data record of the atmospheric column abundance of the hydroxyl radical (OH) using the technique of high resolution solar absorption spectroscopy. We report new efforts in improving the precision of the OH measurements in order to better model the diurnal, seasonal, and interannual variability of odd hydrogen (HOx) chemistry in the stratosphere, which, in turn, will improve our understanding of ozone chemistry and its long-term changes. Until the present, the retrieval method has used a single strong OH absorption line P-1 (1) in the near-ultraviolet at 32,341 cm(-1). We describe a new method that uses an average based on spectral fits to multiple lines weighted by line strength and fitting precision. We have also made a number of improvements in the ability to fit a model to the spectral feature, which substantially reduces the scatter in the measurements of OH abundances. (c) 2008 Optical Society of America
C1 [Cheung, Ross; Li, King Fai; Yung, Yuk L.] CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA.
[Wang, Shuhui; Pongetti, Thomas J.; Cageao, Richard P.; Sander, Stanley P.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Cheung, R (reprint author), CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA.
EM rjc@gps.caltech.edu
OI Li, King-Fai/0000-0003-0150-2910
FU NASA Undergraduate Student Research Program (USRP); Caltech Summer
Undergraduate Research Fellowship (SURF); NASA Upper Atmosphere
Research; Aura Validation, Solar Occultation Satellite Science, and
Tropospheric Chemistry Programs; National Aeronautics and Space
Administration (NASA)
FX We thank Run-Lie Shia for many valuable discussions on the numerical
methods used in this work. We acknowledge the support of the NASA
Undergraduate Student Research Program (USRP), the Caltech Summer
Undergraduate Research Fellowship (SURF) program, and the NASA Upper
Atmosphere Research, Aura Validation, Solar Occultation Satellite
Science, and Tropospheric Chemistry Programs. Work at the Jet Propulsion
Laboratory, California Institute of Technology, is under contract to the
National Aeronautics and Space Administration (NASA).
NR 34
TC 2
Z9 3
U1 0
U2 6
PU OPTICAL SOC AMER
PI WASHINGTON
PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA
SN 1559-128X
EI 2155-3165
J9 APPL OPTICS
JI Appl. Optics
PD NOV 20
PY 2008
VL 47
IS 33
BP 6277
EP 6284
DI 10.1364/AO.47.006277
PG 8
WC Optics
SC Optics
GA 384FF
UT WOS:000261729000018
PM 19023394
ER
PT J
AU Huffenberger, KM
Eriksen, HK
Hansen, FK
Banday, AJ
Gorski, KM
AF Huffenberger, K. M.
Eriksen, H. K.
Hansen, F. K.
Banday, A. J.
Gorski, K. M.
TI THE SCALAR PERTURBATION SPECTRAL INDEX n(s): WMAP SENSITIVITY TO
UNRESOLVED POINT SOURCES
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE cosmic microwave background; cosmological parameters; cosmology:
observations; methods: data analysis
ID ANGULAR POWER SPECTRUM; 2003 FLIGHT; ANISOTROPY; BOOMERANG
AB Precision measurement of the scalar perturbation spectral index, n(s), from the Wilkinson Microwave Anisotropy Probe (WMAP) temperature angular power spectrum requires the subtraction of unresolved point-source power. Here we reconsider this issue, attempting to resolve inconsistencies found in the literature. First, we note a peculiarity in the WMAP temperature likelihood's response to the source correction: cosmological parameters do not respond to increased source errors. An alternative and more direct method for treating this error term acts more sensibly, and also shifts n(s) by similar to 0.3 sigma closer to unity. Second, we re-examine the source fit used to correct the power spectrum. This fit depends strongly on the Galactic cut and the weighting of the map, indicating that either the source population or masking procedure is not isotropic. Jackknife tests appear inconsistent, causing us to assign large uncertainties to account for possible systematics. Third, we note that the WMAP team's spectrum was computed with two different weighting schemes: uniform weights transition to inverse noise variance weights at l = 500. The fit depends on such weighting schemes, so different corrections apply to each multipole range. For the Kp2 mask used in cosmological analysis, we prefer source corrections A = 0.012 +/- 0.005 mu K-2 for uniform weighting and A = 0.015 +/- 0.005 mu K-2 for Nobs weighting. Correcting WMAP's spectrum correspondingly, we compute cosmological parameters with our alternative likelihood, finding n(s) = 0.970 +/- 0.017 and sigma(8) = 0.778 +/- 0.045. This n(s) is only 1.8 sigma from unity, compared to the similar to 2.6 sigma WMAP 3 year result. Finally, an anomalous feature in the source spectrum at l < 200 remains in the 3 year data, most strongly associated with the W band. We note the implications of these results for the 5 year data.
C1 [Huffenberger, K. M.; Gorski, K. M.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[Huffenberger, K. M.; Gorski, K. M.] CALTECH, Pasadena, CA 91125 USA.
[Eriksen, H. K.; Hansen, F. K.] Univ Oslo, Inst Theoret Astrophys, N-0315 Oslo, Norway.
[Eriksen, H. K.; Hansen, F. K.] Univ Oslo, Ctr Math Applicat, N-0316 Oslo, Norway.
[Banday, A. J.] Max Planck Inst Astrophys, D-85741 Garching, Germany.
[Gorski, K. M.] Univ Warsaw Observ, PL-00478 Warsaw, Poland.
RP Huffenberger, KM (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM huffenbe@jpl.nasa.gov
NR 24
TC 7
Z9 7
U1 0
U2 2
PU IOP PUBLISHING LTD
PI BRISTOL
PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND
SN 0004-637X
EI 1538-4357
J9 ASTROPHYS J
JI Astrophys. J.
PD NOV 20
PY 2008
VL 688
IS 1
BP 1
EP 11
DI 10.1086/592030
PG 11
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 370NU
UT WOS:000260769700001
ER
PT J
AU Kazantzidis, S
Bullock, JS
Zentner, AR
Kravtsov, AV
Moustakas, LA
AF Kazantzidis, Stelios
Bullock, James S.
Zentner, Andrew R.
Kravtsov, Andrey V.
Moustakas, Leonidas A.
TI COLD DARK MATTER SUBSTRUCTURE AND GALACTIC DISKS. I. MORPHOLOGICAL
SIGNATURES OF HIERARCHICAL SATELLITE ACCRETION
SO ASTROPHYSICAL JOURNAL
LA English
DT Review
DE cosmology: theory; dark matter; galaxies: formation; galaxies:
kinematics and dynamics; galaxies: structure; methods: numerical
ID DIGITAL SKY SURVEY; SAGITTARIUS DWARF GALAXY; EXPLORING HALO
SUBSTRUCTURE; SURVEY COMMISSIONING DATA; ANGULAR-MOMENTUM PROBLEM;
MILKY-WAY TOMOGRAPHY; EDGE-ON GALAXIES; CANIS-MAJOR; STELLAR HALO; TIDAL
STREAM
AB We conduct dissipationless N-body simulations to investigate the cumulative effect of substructure impacts onto thin disk galaxies in the context of the Lambda CDM paradigm. Our simulation campaign is based on a hybrid approach combining cosmological simulations and controlled numerical experiments. Substructure properties are culled from cosmological simulations of galaxy-sized CDM halos. We demonstrate that accretions of massive subhalos onto the central regions of host halos, where the galactic disk resides, since z similar to 1 should be common occurrences. In contrast, extremely few satellites in present-day CDM halos are likely to have a significant impact on the disk structure. One host halo merger history is subsequently used to seed controlled N-body experiments of repeated satellite encounters with an initially thin Milky-Way (MW) type disk galaxy. These simulations track the effects of six dark matter substructures, with initial masses in the range similar to(0.7-2) x 10(10) M-circle dot (similar to 20%-60% of the disk mass), crossing the disk in the past similar to 8 Gyr. We demonstrate that these accretion events produce several distinctive morphological signatures in the disk, including long-lived, low surface brightness, ringlike features in the outskirts; significant flares; bars; and faint filamentary structures above the disk plane. The final distribution of disk stars exhibits a complex vertical structure that is well described by a standard "thin-thick'' disk decomposition. We compare one of the resulting ringlike features in our simulations to the Monoceros Ring stellar structure in the MW. The comparison shows quantitative agreement in spatial distribution and kinematics, suggesting that such observed complex stellar components may arise naturally as disk stars are excited by encounters with CDM substructure. We conclude that satellite-disk interactions of the kind expected in Lambda CDM models can induce morphological features in galactic disks that are similar to those being discovered in the Milky Way, M31, and other disk galaxies. These results highlight the significant role of CDM substructure in setting the structure of disk galaxies and driving galaxy evolution. Upcoming galactic structure surveys and astrometric satellites may be able to distinguish between competing cosmological models by testing whether the detailed structure of galactic disks is as excited as predicted by the CDM paradigm.
C1 [Kazantzidis, Stelios] Stanford Univ, Dept Phys, Menlo Pk, CA 94025 USA.
[Kazantzidis, Stelios] Stanford Univ, Stanford Linear Accelerator Ctr, Menlo Pk, CA 94025 USA.
[Kazantzidis, Stelios] Stanford Univ, Kavli Inst Particle Astrophys & Cosmol, Menlo Pk, CA 94025 USA.
[Bullock, James S.] Univ Calif Irvine, Ctr Cosmol, Irvine, CA 92697 USA.
[Bullock, James S.] Univ Calif Irvine, Dept Phys & Astron, Irvine, CA 92697 USA.
[Zentner, Andrew R.] Univ Pittsburgh, Dept Phys & Astron, Pittsburgh, PA 15260 USA.
[Kravtsov, Andrey V.] Univ Chicago, Kavli Inst Cosmol Phys, Chicago, IL 60637 USA.
[Kravtsov, Andrey V.] Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA.
[Kravtsov, Andrey V.] Univ Chicago, Enrico Fermi Inst, Chicago, IL 60637 USA.
[Moustakas, Leonidas A.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Kazantzidis, S (reprint author), Ohio State Univ, Ctr Cosmol & Astro Particle Phys, Columbus, OH 43210 USA.
EM stelios@slac.stanford.edu; bullock@uci.edu; zentner@pitt.edu;
andrey@oddjob.uchicago.edu; leonidas@jpl.nasa.gov
RI Moustakas, Leonidas/F-3052-2014; Bullock, James/K-1928-2015
OI Moustakas, Leonidas/0000-0003-3030-2360; Bullock,
James/0000-0003-4298-5082
FU Kavli Institute for Particle Astrophysics and Cosmology (KIPAC); NSF
[AST 05-07916, AST 06-07377, AST 02-39759, AST 05-07596]; University of
Pittsburgh; KICP
FX The authors are grateful to Andrew Benson, Jeffrey Crane, Annette
Ferguson, Andreea Font, Zeljko Ivezic, Kathryn Johnston, Lucio Mayer,
Ben Moore, Jorge Penarrubia, Tom Quinn, Helio Rocha-Pinto, Steven Snell,
Joachim Stadel, and Octavio Valenzuela for many stimulating discussions
and Jeffrey Crane for making available in electronic format data from
his sample of M giants in the Monoceros stream. S. K. would like to
thank Frank van den Bosch for communicating unpublished results and John
Dubinski and Larry Widrow for kindly making available the software used
to set up the primary galaxy model. S. K., J. S. B., and A. V. K.
acknowledge the Aspen Center for Physics for hosting the summer workshop
"Deconstructing the Local Group-Dissecting Galaxy Formation in our Own
Background'' where some of this work was completed. S. K. is also
grateful to the Research Center for Astronomy and Applied Mathematics at
the Academy of Athens for their hospitality during a visit when the
final stages of this work were completed. S. K. is supported by a Kavli
Institute for Particle Astrophysics and Cosmology (KIPAC) Postdoctoral
Fellowship at Stanford University. J. S. B. is supported by NSF grants
AST 05-07916 and AST 06-07377. A. R. Z. is funded by the University of
Pittsburgh. A. V. K. is supported by the NSF grants AST 02-39759 and AST
05-07596 and by KICP. The work of L. A. M. was carried out at the Jet
Propulsion Laboratory, California Institute of Technology under a
contract with NASA. The numerical simulations were performed on the zBox
supercomputer at The University of Zurich and on the Cosmos cluster at
the Jet Propulsion Laboratory. This research made use of the NASA
Astrophysics Data System.
NR 173
TC 173
Z9 173
U1 0
U2 7
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD NOV 20
PY 2008
VL 688
IS 1
BP 254
EP 276
DI 10.1086/591958
PG 23
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 370NU
UT WOS:000260769700024
ER
PT J
AU Hrivnak, BJ
Smith, N
Su, KYL
Sahai, R
AF Hrivnak, Bruce J.
Smith, Nathan
Su, Kate Y. L.
Sahai, Raghvendra
TI A STUDY OF H-2 EMISSION IN THREE BIPOLAR PROTO-PLANETARY NEBULAE: IRAS
16594-4656, HEN 3-401, AND ROB 22
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE circumstellar matter; infrared: stars; ISM: individual (Hen 3-401, IRAS
16594-4656, Rob 22); planetary nebulae: general; stars: AGB and
post-AGB; stars: mass loss
ID HUBBLE-SPACE-TELESCOPE; NICMOS IMAGING POLARIMETRY; PRE-PLANETARY
NEBULAE; DUST SHELL STRUCTURE; POST-AGB STARS; OBSERVATORY OBSERVATIONS;
POLARIZED-LIGHT; CO OBSERVATIONS; SNAPSHOT SURVEY; FAST WIND
AB We have carried out a spatial-kinematic study of three proto-planetary nebulae, IRAS 16594-4656, Hen 3-401, and Rob 22. High-resolution H-2 images were obtained with NICMOS on the Hubble Space Telescope, and high-resolution spectra were obtained with the Phoenix spectrograph on Gemini-South. IRAS 16594-4656 shows a "peanut-shaped'' bipolar structure with H-2 emission from the walls and from two pairs of more distant, point-symmetric faint blobs. The velocity structure shows the polar axis to be in the plane of the sky, contrary to the impression given by the more complex visual image and the visibility of the central star, with an ellipsoidal velocity structure. Hen 3-401 shows the H-2 emission coming from the walls of the very elongated, open-ended lobes seen in visible light, along with a possible small disk around the star. The bipolar lobes appear to be tilted 10 degrees-15 degrees with respect to the plane of the sky, and their kinematics display a Hubble-like flow. In Rob 22, the H-2 appears in the form of an "S''-shape, approximately tracing out the similar pattern seen in the visible. H-2 is especially seen at the ends of the lobes and at two opposite regions close to the unseen central star. The axis of the lobes is nearly in the plane of the sky. Expansion ages of the lobes are calculated to be similar to 1600 yr (IRAS 16594-4656), similar to 1100 yr (Hen 3-401), and similar to 640 yr (Rob 22), based on approximate distances.
C1 [Hrivnak, Bruce J.] Valparaiso Univ, Dept Phys & Astron, Valparaiso, IN 46383 USA.
[Smith, Nathan] Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA.
[Su, Kate Y. L.] Univ Arizona, Steward Observ, Tucson, AZ 85721 USA.
[Sahai, Raghvendra] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Hrivnak, BJ (reprint author), Valparaiso Univ, Dept Phys & Astron, Valparaiso, IN 46383 USA.
EM bruce.hrivnak@valpo.edu; nathans@astro.berkeley.edu; ksu@as.arizona.edu;
raghvendra.sahai@jpl.nasa.gov
FU NASA [GO-07840.02-A, GO-09366.01-A, GO-07840.01-A, GO-09463.01-A,
GO-09801.01-A, HF-01166.01A, GO-09366.03-A]; Space Telescope Science
Institute; Association of Universities for Research in Astronomy, Inc.,
under NASA [NAS5-26555]; National Science Foundation [0407087]; NASA
LTSA award [399-20-40-06]; Jet Propulsion Laboratory, California
Institute of Technology; National Aeronautics and Space Administration
FX We thank Steve Ridgway, Bernadette Rogers, Kevin Volk, and Claudia Winge
for making the Phoenix queue observations; Ken Hinkle for assistance in
planning the Phoenix observing programs; and Anibal Garcia-Hernandez and
Griet Van de Steene for making available to us their medium-resolution 2
mu m spectra in digital form. We thank Nico Koning for making the SHAPE
images and Wenxian Lu for help with the image measurements. The comments
of the referee were helpful in improving the presentation. We
acknowledge grants from NASA that provided partial support for B.J.H.
(GO-07840.02-A and GO-09366.01-A), R. S. (GO-07840.01-A, GO-09463.01-A,
and GO-09801.01-A), N.S. (HF-01166.01A), and K.Y.L.S. (GO-09366.03-A)
from the Space Telescope Science Institute, which is operated by the
Association of Universities for Research in Astronomy, Inc., under NASA
contract NAS5-26555. B.J.H. also acknowledges the support of the
National Science Foundation under grant 0407087, and R. S. thanks NASA
for partially funding this work by a NASA LTSA award (399-20-40-06).
Some of the research described in this paper was carried out by R. S. at
the Jet Propulsion Laboratory, California Institute of Technology, under
a contract with the National Aeronautics and Space Administration. This
research made use of the SIMBAD database, operated at CDS, Strasbourg,
France, and NASA's Astrophysics Data System.
NR 58
TC 5
Z9 5
U1 1
U2 4
PU IOP PUBLISHING LTD
PI BRISTOL
PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD NOV 20
PY 2008
VL 688
IS 1
BP 327
EP 343
DI 10.1086/591960
PG 17
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 370NU
UT WOS:000260769700029
ER
PT J
AU Sivaramakrishnan, A
Soummer, R
Pueyo, L
Wallace, JK
Shao, M
AF Sivaramakrishnan, Anand
Soummer, Remi
Pueyo, Laurent
Wallace, J. Kent
Shao, Michael
TI SENSING PHASE ABERRATIONS BEHIND LYOT CORONAGRAPHS
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE instrumentation: adaptive optics; instrumentation: high angular
resolution; planetary systems; space vehicles; techniques: high angular
resolution
ID EXTREME ADAPTIVE OPTICS; SPECKLE NOISE ATTENUATION; DYNAMIC-RANGE;
EXTRASOLAR PLANETS; STREHL RATIO; CALIBRATION; COMPANIONS; APERTURES;
IMAGES; SPECTROSCOPY
AB Direct detection of young extrasolar planets orbiting nearby stars can be accomplished from the ground with extreme adaptive optics and coronagraphy in the near-infrared, as long as this combination can provide an image with a dynamic range of 10(7) after the data are processed. Slowly varying speckles due to residual phase aberrations that are not measured by the primary wave-front sensor are the primary obstacle to achieving such a dynamic range. In particular, non-common optical path aberrations occurring between the wave-front sensor and the coronagraphic occulting spot degrade performance the most. We analyze the passage of both low and high spatial frequency phase ripples, as well as low-order Zernike aberrations, through an apodized pupil Lyot coronagraph in order to demonstrate the way coronagraphic filtering affects various aberrations. We derive the coronagraphically induced cutoff frequency of the filtering and estimate coronagraphic contrast losses due to low-order Zernike aberrations: tilt, astigmatism, defocus, coma, and spherical aberration. Such slowly varying path errors can be measured behind a coronagraph and corrected by a slowly updated optical path delay precompensation or offset asserted on the wave front by the adaptive optics (AO) system. We suggest ways of measuring and correcting all but the lowest spatial frequency aberrations using Lyot plane wave-front data, in spite of the complex interaction between the coronagraph and those mid-spatial frequency aberrations that cause image plane speckles near the coronagraphic focal plane mask occulter's edge. This investigation provides guidance for next-generation coronagraphic instruments currently under construction.
C1 [Sivaramakrishnan, Anand; Soummer, Remi] Amer Museum Nat Hist, Dept Astrophys, New York, NY 10024 USA.
[Pueyo, Laurent] Princeton Univ, Dept Mech & Aerosp Engn, Princeton, NJ 08544 USA.
[Wallace, J. Kent; Shao, Michael] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Sivaramakrishnan, A (reprint author), Amer Museum Nat Hist, Dept Astrophys, 79th St,Cent Pk W, New York, NY 10024 USA.
FU National Science Foundation [AST-0334916, AST-0215793, AST-0520822,
AST-0628877, AST-0804417]; National Aeronautics and Space Administration
under the Terrestrial Planet Finder Foundation Science Program
[NNG05GJ86G]; NASA Michelson Postdoctoral Fellowship; NASA; Kalbfleisch
Postdoctoral Fellowship; National Science Foundation Science and
Technology Center for Adaptive Optics [AST 98-76783]
FX We thank Christian Marois and Bruce Macintosh for insightful discussions
and the anonymous referee for very helpful suggestions. This work has
been partially supported by the National Science Foundation under grants
AST-0334916, AST-0215793, AST-0520822, AST-0628877, and AST-0804417, as
well as grant NNG05GJ86G from the National Aeronautics and Space
Administration under the Terrestrial Planet Finder Foundation Science
Program. R. S. was supported in part by a NASA Michelson Postdoctoral
Fellowship under contract to the Jet Propulsion Laboratory (JPL) funded
by NASA. The JPL is managed for NASA by the California Institute of
Technology. R. S. was also supported in part by a Kalbfleisch
Postdoctoral Fellowship. This work was supported in part by the National
Science Foundation Science and Technology Center for Adaptive Optics,
managed by the University of California at Santa Cruz under cooperative
agreement AST 98-76783.
NR 61
TC 19
Z9 19
U1 0
U2 3
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD NOV 20
PY 2008
VL 688
IS 1
BP 701
EP 708
DI 10.1086/591957
PG 8
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 370NU
UT WOS:000260769700057
ER
PT J
AU Adler, RF
Gu, GJ
Wang, JJ
Huffman, GJ
Curtis, S
Bolvin, D
AF Adler, Robert F.
Gu, Guojun
Wang, Jian-Jian
Huffman, George J.
Curtis, Scott
Bolvin, David
TI Relationships between global precipitation and surface temperature on
interannual and longer timescales (1979-2006)
SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
LA English
DT Article
ID EL-NINO; SOUTHERN-OSCILLATION; HYDROLOGIC-CYCLE; CLIMATE-CHANGE;
UNITED-STATES; WATER-VAPOR; TRENDS; VARIABILITY; EVOLUTION; PACIFIC
AB Associations between global and regional precipitation and surface temperature anomalies on interannual and longer timescales are explored for the period of 1979-2006 using the GPCP precipitation product and the NASA-GISS surface temperature data set. Positive (negative) correlations are generally confirmed between these two variables over tropical oceans (lands). ENSO is the dominant factor in these interannual tropical relations. Away from the tropics, particularly in the Northern Hemisphere mid-high latitudes, this correlation relationship becomes much more complicated with positive and negative values of correlation tending to appear over both ocean and land, with a strong seasonal variation in the correlation patterns. Relationships between long-term linear changes in global precipitation and surface temperature are also assessed. Most intense long-term, linear changes in annual-mean rainfall during the data record tend to be within the tropics. For surface temperature however, the strongest linear changes are observed in the Northern Hemisphere mid-high latitudes, with much weaker temperature changes in the tropical region and Southern Hemisphere. Finally, the ratios between the linear changes in zonal-mean rainfall and temperature anomalies over the period are estimated. Globally, the calculation results in a +2.3%/degrees C precipitation change, although the magnitude is sensitive to small errors in the precipitation data set and to the length of record used for the calculation. The long-term temperature-precipitation relations are also compared to the interannual variations of the same ratio in a zonally averaged sense and are shown to have similar profiles, except for over tropical land areas.
C1 [Adler, Robert F.] Univ Maryland, Earth Syst Sci Interdisciplinary Ctr, College Pk, MD 20742 USA.
[Adler, Robert F.; Gu, Guojun; Wang, Jian-Jian; Huffman, George J.; Bolvin, David] NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA.
[Gu, Guojun; Wang, Jian-Jian] Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21228 USA.
[Huffman, George J.; Bolvin, David] Sci Syst & Applicat Inc, Lanham, MD USA.
[Curtis, Scott] E Carolina Univ, Dept Geog, Greenville, NC USA.
RP Adler, RF (reprint author), Univ Maryland, Earth Syst Sci Interdisciplinary Ctr, College Pk, MD 20742 USA.
EM robert.f.adler@nasa.gov
RI Curtis, Scott/C-1115-2013; Huffman, George/F-4494-2014;
OI Huffman, George/0000-0003-3858-8308; Curtis, Scott/0000-0001-9065-8639
FU NASA Energy and Water-cycle Study (NEWS)
FX The global surface temperature anomaly product and global mean
stratospheric aerosol optical thickness data were provided by the
NASA-GISS from its website at http://data.giss.nasa.gov/. This research
is supported under the NASA Energy and Water-cycle Study (NEWS) program.
NR 39
TC 68
Z9 70
U1 5
U2 30
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 2169-897X
EI 2169-8996
J9 J GEOPHYS RES-ATMOS
JI J. Geophys. Res.-Atmos.
PD NOV 20
PY 2008
VL 113
AR D22104
DI 10.1029/2008JD010536
PG 15
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 375WP
UT WOS:000261144800006
ER
PT J
AU Guinn, JR
Garcia, MD
Talley, K
AF Guinn, Joseph R.
Garcia, Mark D.
Talley, Kevin
TI Mission design of the Phoenix Mars Scout mission
SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS
LA English
DT Article
AB The Phoenix Mars Scout Lander, the first robotic explorer in NASA's "Scout Program,'' launched on 4 August 2007, will land on the northern plains of Mars in late May 2008, prior to the northern Martian summer. The Phoenix mission "follows the water'' by landing in a region where NASA's Mars Odyssey orbiter has discovered evidence of ice-rich soil very near the Martian surface. For 3 months after arrival, the fixed Lander will perform in situ investigations that will characterize the chemistry of the materials at the local surface, subsurface, and atmosphere, and will identify potential evidence of key elements significant to the biological potential of Mars. The Lander will employ a robotic arm to dig to the ice layer, and will analyze the acquired samples using a suite of deck-mounted science instruments. The development of the baseline strategy to achieve the objectives of this mission involves the integration of a variety of elements into a coherent mission plan. These elements are involved in defining plans for the launch phase, interplanetary cruise, atmospheric entry, descent and landing, landing site selection, and the surface operations. An overview of the integrated mission plan, from launch through surface operations, is described.
C1 [Guinn, Joseph R.; Garcia, Mark D.; Talley, Kevin] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Guinn, JR (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM mark.d.garcia@jpl.nasa.gov; kevin.talley@jpl.nasa.gov
FU National Aeronautics and Space Administration
FX The work described in this paper was performed at the Jet Propulsion
Laboratory, California Institute of Technology, under a contract with
the National Aeronautics and Space Administration. The authors would
like to thank their families for their support as this manuscript was
compiled and their patience and understanding of the demands that come
from working on a planetary flight project. The authors are also
grateful for the tremendous work done by the rest of the Mission Design
and Navigation team at JPL: Brian Portock, Lynn Craig, Behzad Raofi, Ken
Williams, Eunice Lau, Mark Ryne, and Gene Bonfiglio, that is showcased
here.
NR 8
TC 4
Z9 4
U1 0
U2 1
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0148-0227
J9 J GEOPHYS RES-PLANET
JI J. Geophys. Res.-Planets
PD NOV 20
PY 2008
VL 113
AR E00A26
DI 10.1029/2007JE003038
PG 16
WC Geochemistry & Geophysics
SC Geochemistry & Geophysics
GA 375XD
UT WOS:000261146200001
ER
PT J
AU Chang, J
Adams, JH
Ahn, HS
Bashindzhagyan, GL
Christl, M
Ganel, O
Guzik, TG
Isbert, J
Kim, KC
Kuznetsov, EN
Panasyuk, MI
Panov, AD
Schmidt, WKH
Seo, ES
Sokolskaya, NV
Watts, JW
Wefel, JP
Wu, J
Zatsepin, VI
AF Chang, J.
Adams, J. H., Jr.
Ahn, H. S.
Bashindzhagyan, G. L.
Christl, M.
Ganel, O.
Guzik, T. G.
Isbert, J.
Kim, K. C.
Kuznetsov, E. N.
Panasyuk, M. I.
Panov, A. D.
Schmidt, W. K. H.
Seo, E. S.
Sokolskaya, N. V.
Watts, J. W.
Wefel, J. P.
Wu, J.
Zatsepin, V. I.
TI An excess of cosmic ray electrons at energies of 300-800 GeV
SO NATURE
LA English
DT Article
ID SUPERNOVA REMNANT; SPECTRUM; PARTICLE
AB Galactic cosmic rays consist of protons, electrons and ions, most of which are believed to be accelerated to relativistic speeds in supernova remnants(1-3). All components of the cosmic rays show an intensity that decreases as a power law with increasing energy ( for example as E 22.7). Electrons in particular lose energy rapidly through synchrotron and inverse Compton processes, resulting in a relatively short lifetime ( about 10 5 years) and a rapidly falling intensity, which raises the possibility of seeing the contribution from individual nearby sources ( less than one kiloparsec away)(4). Here we report an excess of galactic cosmic- ray electrons at energies of,300 - 800 GeV, which indicates a nearby source of energetic electrons. Such a source could be an unseen astrophysical object ( such as a pulsar(5) or micro-quasar(6)) that accelerates electrons to those energies, or the electrons could arise from the annihilation of dark matter particles ( such as a Kaluza-Klein particle(7) with a mass of about 620 GeV).
C1 [Guzik, T. G.; Isbert, J.; Wefel, J. P.] Louisiana State Univ, Dept Phys & Astron, Baton Rouge, LA 70803 USA.
[Chang, J.] CAS, Purple Mt Observ, Nanjing 210008, Peoples R China.
[Chang, J.; Schmidt, W. K. H.] Max Planck Inst Sonnensyst Forsch, D-37191 Katlenburg Lindau, Germany.
[Adams, J. H., Jr.; Christl, M.; Watts, J. W.] NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA.
[Ahn, H. S.; Ganel, O.; Kim, K. C.; Seo, E. S.; Wu, J.] Univ Maryland, Inst Phys Sci & Technol, College Pk, MD 20742 USA.
[Bashindzhagyan, G. L.; Kuznetsov, E. N.; Panasyuk, M. I.; Panov, A. D.; Sokolskaya, N. V.; Zatsepin, V. I.] Moscow MV Lomonosov State Univ, Skobeltsyn Inst Nucl Phys, Moscow 119991, Russia.
RP Wefel, JP (reprint author), Louisiana State Univ, Dept Phys & Astron, Baton Rouge, LA 70803 USA.
EM wefel@phunds.phys.lsu.edu
RI Panasyuk, Mikhail/E-2005-2012; Zatsepin, Victor/J-2287-2012; Sokolskaya,
Natalia/J-4609-2012; Panov, Alexander/K-3952-2012;
OI Panov, Alexander/0000-0003-2290-6498; Seo, Eun-Suk/0000-0001-8682-805X
FU NASA; Russian Foundation for Basic Research; National Natural Science
Foundation
FX This research was supported in the USA by NASA, in Russia by the Russian
Foundation for Basic Research, and in China by the National Natural
Science Foundation. The help of the NASA BPO and CSBF during balloon
flights and the US NSF and RPSC for Antarctica operations is gratefully
acknowledged.
NR 32
TC 730
Z9 749
U1 3
U2 38
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
J9 NATURE
JI Nature
PD NOV 20
PY 2008
VL 456
IS 7220
BP 362
EP 365
DI 10.1038/nature07477
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA 374JM
UT WOS:000261039600037
PM 19020615
ER
PT J
AU Ngwira, CM
Pulkkinen, A
McKinnell, LA
Cilliers, PJ
AF Ngwira, Chigomezyo M.
Pulkkinen, Antti
McKinnell, Lee-Anne
Cilliers, Pierre J.
TI Improved modeling of geomagnetically induced currents in the South
African power network
SO SPACE WEATHER-THE INTERNATIONAL JOURNAL OF RESEARCH AND APPLICATIONS
LA English
DT Article
ID TECHNOLOGICAL SYSTEMS; CONDUCTIVITY; FIELDS
AB Geomagnetically induced currents (GICs), resulting from adverse space weather, have been demonstrated to cause damage to power transformers in the midlatitudes. There is growing concern over possible GIC effects in the Southern African network because of its long power lines. Previous efforts to model the electric field associated with GICs in South Africa have used a uniform ground conductivity model. In an effort to improve the modeling of GICs, GIC data together with the Hermanus Magnetic Observatory geomagnetic field data were used in order to obtain a multilayered ground conductivity structure. The method requires a definition of the network coefficients, which are then used in subsequent calculations. This study shows that GIC computed using the new network coefficients and the multilayered ground conductivity model improves the accuracy of GIC modeling. GIC statistics are then derived on the basis of the recordings of the geomagnetic field from 1996 to 2006 at Hermanus, the new network coefficients, and ground conductivity model. The geoelectric field was modeled using the plane wave method.
C1 [Ngwira, Chigomezyo M.; McKinnell, Lee-Anne] Rhodes Univ, Dept Phys & Elect, ZA-6140 Grahamstown, South Africa.
[Ngwira, Chigomezyo M.; McKinnell, Lee-Anne; Cilliers, Pierre J.] Hermanus Magnet Observ, ZA-7200 Hermanus, South Africa.
[Pulkkinen, Antti] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
[Pulkkinen, Antti] Univ Maryland, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21201 USA.
RP Ngwira, CM (reprint author), Rhodes Univ, Dept Phys & Elect, ZA-6140 Grahamstown, South Africa.
EM chigongwira@yahoo.co.uk
RI ngwira, chigomezyo/D-7310-2012
FU National Astrophysics and Space Science Programme of South Africa
FX We would like to extend our gratitude to Trevor Gaunt for providing the
GIC data. Special thanks to Risto Pirjola and Larisa Trichtchenko for
their support and continued interest in our work. Alan Jones is
acknowledged for his comments on the validity of 1-D conductivity models
for South Africa. We also thank Edward Bernhardi, Mark Hamilton, and
Peter Fernberg for their assistance in this work. The work of Chigomezyo
Ngwira was supported by the National Astrophysics and Space Science
Programme of South Africa.
NR 18
TC 22
Z9 22
U1 0
U2 2
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 1542-7390
J9 SPACE WEATHER
JI Space Weather
PD NOV 20
PY 2008
VL 6
IS 11
AR S11004
DI 10.1029/2008SW000408
PG 8
WC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology &
Atmospheric Sciences
SC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology &
Atmospheric Sciences
GA 375XQ
UT WOS:000261147500001
ER
PT J
AU Smith, EJ
Balogh, A
AF Smith, Edward J.
Balogh, Andre
TI Decrease in heliospheric magnetic flux in this solar minimum: Recent
Ulysses magnetic field observations
SO GEOPHYSICAL RESEARCH LETTERS
LA English
DT Article
AB The Ulysses spacecraft has traveled from the solar equator at 1.3 and 5.3 AU to above the polar caps at 2.2 AU three times during the last 17 years and has provided measurements of the solar-heliospheric magnetic field. The open magnetic flux, i.e., the radial component, B(R), multiplied by the square of the radial distance, r, is independent of latitude at both solar minimum and maximum. Measurements of r(2) B(R) contain information about the average polar cap field strength when allowance is made for the non-radial expansion of the magnetic field and solar wind near the Sun that eliminates the latitude gradient in magnetic pressure. Recent Earth-based magnetograph observations indicate that the Sun's polar cap field strength, BP, has decreased by a factor of about two between the previous and present latitude scans. Ulysses measurements show that the average value of r(2) B(R) has decreased from 3.6 nT (AU)(2) in 1993.5 to 1995.0 to 2.3 nT (AU)(2) in 2006.1 to 2007.4, a decrease by 0.64. The two Ulysses scans are not precisely at solar minimum. However, in-ecliptic BR is highly correlated with the Ulysses measurements at all latitudes and can be used to determine the open flux at the two solar minima. Averages of B(R) at the two solar minima are 2.82 and 2.45 nT. This decrease is contrary to the suggestion based on previous solar cycles that BR returns to the same value of approximate to 3 nT at solar minimum. The ratio of BP to the expansion factor, f(E), is proportional to the measured open flux and observed and assumed values of BP are used to determine the corresponding values of f(E). Another property of the fast solar wind is that it is highly turbulent compared to lower latitudes. To determine if the decrease in r(2) B(R) and B(P) has affected the intensity of the magnetic fluctuations, the total variances in the magnetic field fluctuations are derived and found to decrease by a factor of 0.75. Citation: Smith, E. J., and A. Balogh ( 2008), Decrease in heliospheric magnetic flux in this solar minimum: Recent Ulysses magnetic field observations, Geophys. Res. Lett., 35, L22103, doi: 10.1029/2008GL035345.
C1 [Smith, Edward J.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[Balogh, Andre] Univ London Imperial Coll Sci Technol & Med, Blackett Lab, London SW7 2AZ, England.
RP Smith, EJ (reprint author), CALTECH, Jet Prop Lab, Mail Stop 169-506,4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM edward.j.smith@jpl.nasa.gov
NR 9
TC 125
Z9 126
U1 0
U2 3
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0094-8276
J9 GEOPHYS RES LETT
JI Geophys. Res. Lett.
PD NOV 19
PY 2008
VL 35
IS 22
AR L22103
DI 10.1029/2008GL035345
PG 4
WC Geosciences, Multidisciplinary
SC Geology
GA 375WA
UT WOS:000261143300001
ER
PT J
AU Wang, SH
Pickett, HM
Pongetti, TJ
Cheung, R
Yung, YL
Shim, C
Li, QB
Canty, T
Salawitch, RJ
Jucks, KW
Drouin, B
Sander, SP
AF Wang, Shuhui
Pickett, Herbert M.
Pongetti, Thomas J.
Cheung, Ross
Yung, Yuk L.
Shim, Changsub
Li, Qinbin
Canty, Timothy
Salawitch, Ross J.
Jucks, Kenneth W.
Drouin, Brian
Sander, Stanley P.
TI Validation of Aura Microwave Limb Sounder OH measurements with Fourier
Transform Ultra-Violet Spectrometer total OH column measurements at
Table Mountain, California
SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
LA English
DT Article
ID LEAST-SQUARES FITS; MODEL DESCRIPTION; UPPER TROPOSPHERE; EOS MLS;
SATELLITE; ABUNDANCE; RADICALS; NITROGEN; STRATOSPHERE; CHEMISTRY
AB The first seasonal and interannual validation of OH measurements from the Aura Microwave Limb Sounder (MLS) has been conducted using ground-based OH column measurements from the Fourier Transform Ultra-Violet Spectrometer (FTUVS) over the Jet Propulsion Laboratory's Table Mountain Facility (TMF) during 2004-2007. To compare with FTUVS total column measurements, MLS OH vertical profiles over TMF are integrated to obtain partial OH columns above 21.5 hPa, which covers nearly 90% of the total column. The tropospheric OH and the lower stratopheric OH not measured by MLS are estimated using GEOS (Goddard Earth Observing System)-Chem and a Harvard 2-D model implemented within GEOS-Chem, respectively. A number of field observations and calculations from a photochemical box model are compared to OH profiles from these models to estimate the variability in the lower atmospheric OH and thus the uncertainty in the combined total OH columns from MLS and models. In general, the combined total OH columns agree extremely well with TMF total OH columns, especially during seasons with high OH. In winter with low OH, the combined columns are often higher than TMF measurements. A slightly weaker seasonal variation is observed by MLS relative to TMF. OH columns from TMF and the combined total columns from MLS and models are highly correlated, resulting in a mean slope of 0.969 with a statistically insignificant intercept. This study therefore suggests that column abundances derived from MLS vertical profiles have been validated to within the mutual systematic uncertainties of the MLS and FTUVS measurements.
C1 [Wang, Shuhui; Pickett, Herbert M.; Pongetti, Thomas J.; Shim, Changsub; Li, Qinbin; Drouin, Brian; Sander, Stanley P.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[Canty, Timothy; Salawitch, Ross J.] Univ Maryland, Dept Atmospher & Ocean Sci, College Pk, MD 20742 USA.
[Cheung, Ross; Yung, Yuk L.] CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA.
[Jucks, Kenneth W.] Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA.
[Salawitch, Ross J.] Univ Maryland, Dept Chem & Biochem, College Pk, MD 20742 USA.
RP Wang, SH (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM shuhui.wang@jpl.nasa.gov
RI Salawitch, Ross/B-4605-2009; Canty, Timothy/F-2631-2010; Chem,
GEOS/C-5595-2014
OI Salawitch, Ross/0000-0001-8597-5832; Canty, Timothy/0000-0003-0618-056X;
FU NASA
FX We acknowledge the support of the NASA Upper Atmosphere Research, Aura
Validation, Solar Occultation Satellite Science, and Tropospheric
Chemistry Programs, the NASA Undergraduate Student Research Program
(USRP) and the Caltech Summer Undergraduate Research Fellowship (SURF)
program. We also wish to thank King Fai Li and Run-Lie Shia (Caltech)
for helpful discussions. Alyn Lambert (JPL) is kindly acknowledged for
helping with the orthogonal linear fit. Work at the Jet Propulsion
Laboratory, California Institute of Technology, is under contract to the
National Aeronautics and Space Administration.
NR 34
TC 6
Z9 6
U1 0
U2 8
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 2169-897X
EI 2169-8996
J9 J GEOPHYS RES-ATMOS
JI J. Geophys. Res.-Atmos.
PD NOV 19
PY 2008
VL 113
AR D22301
DI 10.1029/2008JD009883
PG 15
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 375WM
UT WOS:000261144500001
ER
PT J
AU Sergeev, VA
Apatenkov, SV
Angelopoulos, V
McFadden, JP
Larson, D
Bonnell, JW
Kuznetsova, M
Partamies, N
Honary, F
AF Sergeev, V. A.
Apatenkov, S. V.
Angelopoulos, V.
McFadden, J. P.
Larson, D.
Bonnell, J. W.
Kuznetsova, M.
Partamies, N.
Honary, F.
TI Simultaneous THEMIS observations in the near-tail portion of the inner
and outer plasma sheet flux tubes at substorm onset
SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
LA English
DT Article
ID MAGNETOSPHERIC SUBSTORMS; FLOW BURSTS; EXPANSION
AB We analyzed the measurements made by two Time History of Events and Macroscale Interactions during Substorms (THEMIS) probes in ideal observational conditions (quiet background, near midnight, inside the substorm current wedge) during two distinct isolated substorm onsets, with probe P2 measuring the inner plasma sheet at similar to 8 Re and P1 near the plasma sheet-lobe interface at 11-12 Re. The earliest onset-related strong perturbations were observed by P1; they include the increase of both B(z) (dipolarization) and E(y) (a few mV/m) as well as the simultaneous drop in total pressure, indicating the unloading process. This was also accompanied by fast inward plasma motion (up to 100 km/s, toward the neutral sheet) and fast plasma sheet thinning while the poleward auroral expansion was in progress in the conjugate ionosphere. These perturbations were followed after 6-8 min by the rapid expansion of the already heated plasma sheet. While in the adjacent lobe during this thinning phase, probe P1 continued to observe intense flux transfer toward the sheet center plane. The inner probe observed intense dipolarization and inward plasma injection but with a smaller flux transfer and starting 1-2 min after the perturbations at P1, supporting the conclusion that onset instability took place tailward of 12 Re. We also demonstrate the global MHD simulations to show that a nontrivial combination of dipolarization and the plasma sheet thinning may be observed simultaneously in the outmost part of the dipolelike region during a sudden increase of the reconnection rate at the nearby active X line, staying a few Re from the observation point. These observations provide constraints for the choice of substorm onset mechanism and indicate near-Earth magnetic reconnection as the most probable source process.
C1 [Sergeev, V. A.; Apatenkov, S. V.] St Petersburg State Univ, St Petersburg 198504, Russia.
[Angelopoulos, V.] Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA 90024 USA.
[McFadden, J. P.; Larson, D.; Bonnell, J. W.] Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA.
[Kuznetsova, M.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
[Partamies, N.] Finnish Meteorol Inst, FIN-00101 Helsinki, Finland.
[Honary, F.] Univ Lancaster, Dept Commun Syst, Lancaster, England.
RP Sergeev, VA (reprint author), St Petersburg State Univ, St Petersburg 198504, Russia.
EM victor@geo.phys.spbu.ru
RI Kuznetsova, Maria/F-6840-2012; Apatenkov, Sergey/J-4899-2013; Partamies,
Noora/G-3408-2014; Sergeev, Victor/H-1173-2013
OI Partamies, Noora/0000-0003-2536-9341; Sergeev,
Victor/0000-0002-4569-9631
FU German Ministry for Economy and Technology; German Center for Aviation
and Space (DLR) [50 OC 0302]; THEMIS [NAS5-02099]; Russian Ministry of
Science; RFBR [07-02-91703, 07-05-91109]; CRDF [2861]
FX Data from the Intermagnet, IMAGE, and SAMNET magnetometer networks were
used in this study as well as solar wind observations from ACE and Wind
(from the OMNI Web site) and energetic particle data (from the LANL Web
site). We thank all data providers as well as the developers of the
BATSRUS code and the CCMC staff for making the global MHD simulations
available. Thanks to K. H. Glassmeier, U. Auster, and W. Baumjohann for
the use of FGM data provided under the lead of the Technical University
of Braunschweig and with financial support through the German Ministry
for Economy and Technology and the German Center for Aviation and Space
(DLR) under contract 50 OC 0302. We thank M. Holeva and Amanda Prentice
for their help in preparing the manuscript and A. Runov for help in the
THEMIS data processing. The work was supported by THEMIS contract
NAS5-02099. The work by V.S. and S.A. was also supported by Russian
Ministry of Science grants, by RFBR grants 07-02-91703 and 07-05-91109
and CRDF grant 2861.
NR 21
TC 15
Z9 15
U1 0
U2 3
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0148-0227
J9 J GEOPHYS RES-SPACE
JI J. Geophys. Res-Space Phys.
PD NOV 19
PY 2008
VL 113
AR A00C02
DI 10.1029/2008JA013527
PG 11
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 375XJ
UT WOS:000261146800001
ER
PT J
AU Rodrigues, DF
Ivanova, N
He, ZL
Huebner, M
Zhou, JZ
Tiedje, JM
AF Rodrigues, Debora F.
Ivanova, Natalia
He, Zhili
Huebner, Marianne
Zhou, Jizhong
Tiedje, James M.
TI Architecture of thermal adaptation in an Exiguobacterium sibiricum
strain isolated from 3 million year old permafrost: A genome and
transcriptome approach
SO BMC GENOMICS
LA English
DT Article
ID HEAT-SHOCK RESPONSE; ANCIENT SIBERIAN PERMAFROST; ESCHERICHIA-COLI K-12;
BACILLUS-SUBTILIS; LOW-TEMPERATURE; LISTERIA-MONOCYTOGENES;
GENE-EXPRESSION; PROTEOMIC ANALYSIS; STRESS-RESPONSE; SP-NOV
AB Background: Many microorganisms have a wide temperature growth range and versatility to tolerate large thermal fluctuations in diverse environments, however not many have been fully explored over their entire growth temperature range through a holistic view of its physiology, genome, and transcriptome. We used Exiguobacterium sibiricum strain 255-15, a psychrotrophic bacterium from 3 million year old Siberian permafrost that grows from -5 degrees C to 39 degrees C to study its thermal adaptation.
Results: The E. sibiricum genome has one chromosome and two small plasmids with a total of 3,015 protein-encoding genes (CDS), and a GC content of 47.7%. The genome and transcriptome analysis along with the organism's known physiology was used to better understand its thermal adaptation. A total of 27%, 3.2%, and 5.2% of E. sibiricum CDS spotted on the DNA microarray detected differentially expressed genes in cells grown at -2.5 degrees C, 10 degrees C, and 39 degrees C, respectively, when compared to cells grown at 28 degrees C. The hypothetical and unknown genes represented 10.6%, 0.89%, and 2.3% of the CDS differentially expressed when grown at -2.5 degrees C, 10 degrees C, and 39 degrees C versus 28 degrees C, respectively.
Conclusion: The results show that E. sibiricum is constitutively adapted to cold temperatures stressful to mesophiles since little differential gene expression was observed between 4 degrees C and 28 degrees C, but at the extremities of its Arrhenius growth profile, namely -2.5 degrees C and 39 degrees C, several physiological and metabolic adaptations associated with stress responses were observed.
C1 [Rodrigues, Debora F.; Tiedje, James M.] Michigan State Univ, NASA, Astrobiol Inst, E Lansing, MI 48824 USA.
[Rodrigues, Debora F.; Tiedje, James M.] Michigan State Univ, Ctr Microbial Ecol, E Lansing, MI 48824 USA.
[Ivanova, Natalia] DOE Joint Genome Inst, Walnut Creek, CA 94598 USA.
[He, Zhili; Zhou, Jizhong] Univ Oklahoma, Dept Bot & Microbiol, Inst Environm Genom, Norman, OK 73019 USA.
[Huebner, Marianne] Michigan State Univ, Dept Stat & Probabil, E Lansing, MI 48824 USA.
RP Rodrigues, DF (reprint author), Michigan State Univ, NASA, Astrobiol Inst, E Lansing, MI 48824 USA.
EM rodri257@msu.edu; NNIvanova@lbl.gov; zhili.he@ou.edu; huebner@msu.edu;
jzhou@ou.edu; tiedjej@msu.edu
RI Rodrigues, Debora/H-4375-2012; He, Zhili/C-2879-2012;
OI Rodrigues, Debora/0000-0002-3124-1443
FU NASA [NCC2-1274]; The United States Department of Energy
FX This research was supported by a cooperative agreement with NASA
Astrobiology Institute number NCC2-1274. The microarray synthesis was
also supported by The United States Department of Energy under Genomics:
GTL program through the Virtual Institute of Microbial Stress and
Survival (VIMSS; http://vimss.lbl.gov) of the Office of Biological and
Environmental Research, Office of Science. Thanks to Alla Lapidus, Lynne
Goodwin, Sam Pitluck, Linda Peters, Duncan Scott and Thanos Lykidis for
their contributions to the Exiguobacterium sibiricum genome. Thanks to
Miriam L. Land for providing the locus tag mapping tables.
NR 69
TC 39
Z9 40
U1 2
U2 8
PU BIOMED CENTRAL LTD
PI LONDON
PA CURRENT SCIENCE GROUP, MIDDLESEX HOUSE, 34-42 CLEVELAND ST, LONDON W1T
4LB, ENGLAND
SN 1471-2164
J9 BMC GENOMICS
JI BMC Genomics
PD NOV 18
PY 2008
VL 9
AR 547
DI 10.1186/1471-2164-9-547
PG 17
WC Biotechnology & Applied Microbiology; Genetics & Heredity
SC Biotechnology & Applied Microbiology; Genetics & Heredity
GA 403UN
UT WOS:000263107600002
PM 19019206
ER
PT J
AU Zhang, XD
Sorteberg, A
Zhang, J
Gerdes, R
Comiso, JC
AF Zhang, Xiangdong
Sorteberg, Asgeir
Zhang, Jing
Gerdes, Ruediger
Comiso, Josefino C.
TI Recent radical shifts of atmospheric circulations and rapid changes in
Arctic climate system
SO GEOPHYSICAL RESEARCH LETTERS
LA English
DT Article
ID SEA-ICE; OSCILLATION; VARIABILITY
AB Arctic climate system change has accelerated tremendously since the beginning of this century, and a strikingly extreme sea-ice loss occurred in summer 2007. However, the greenhouse-gas-emissions forcing has only increased gradually and the driving role in Arctic climate change of the positively-polarized Arctic/North Atlantic Oscillation (AO/NAO) trend has substantially weakened. Although various contributing factors have been examined, the fundamental physical process, which orchestrates these contributors to drive the acceleration and the latest extreme event, remains unknown. We report on drastic, systematic spatial changes in atmospheric circulations, showing a sudden jump from the conventional tri-polar AO/NAO to an unprecedented dipolar leading pattern, following accelerated northeastward shifts of the AO/NAO centers of action. These shifts provide an accelerating impetus for the recent rapid Arctic climate system changes, perhaps shedding light on recent arguments about a tipping point of global-warming-forced climate change in the Arctic. The radical spatial shift is a precursor to the observed extreme change event, demonstrating skilful information for future prediction. Citation: Zhang, X., A. Sorteberg, J. Zhang, R. Gerdes, and J. C. Comiso (2008), Recent radical shifts of atmospheric circulations and rapid changes in Arctic climate system, Geophys. Res. Lett., 35, L22701, doi: 10.1029/2008GL035607.
C1 [Zhang, Xiangdong] Univ Alaska Fairbanks, Int Arctic Res Ctr, Fairbanks, AK 99775 USA.
[Sorteberg, Asgeir] Bjerknes Ctr Climate Res, N-5007 Bergen, Norway.
[Zhang, Jing] Univ Alaska Fairbanks, Arctic Reg Supercomp Ctr, Fairbanks, AK 99775 USA.
[Gerdes, Ruediger] Alfred Wegener Inst Polar & Marine Res, D-27570 Bremerhaven, Germany.
[Comiso, Josefino C.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
RP Zhang, XD (reprint author), Univ Alaska Fairbanks, Int Arctic Res Ctr, Fairbanks, AK 99775 USA.
EM xdz@iarc.uaf.edu
RI Zhang, Jing/B-3465-2009; Zhang, Xiangdong/A-9711-2009; Sorteberg,
Asgeir/N-8576-2015
OI Zhang, Xiangdong/0000-0001-5893-2888; Sorteberg,
Asgeir/0000-0001-6003-9618
FU JAMSTEC; NOAA CVP; Norwegian NORKLIMA; DOI/MMS
FX We thank S. Hov Moen, X. Wang, L. Vincent, O. Skagseth, M. Serreze, J.
Walsh, and two reviewers for data or comments. This work was supported
by the JAMSTEC, NOAA CVP, Norwegian NORKLIMA, and DOI/MMS.
NR 14
TC 121
Z9 127
U1 2
U2 26
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0094-8276
EI 1944-8007
J9 GEOPHYS RES LETT
JI Geophys. Res. Lett.
PD NOV 18
PY 2008
VL 35
IS 22
AR L22701
DI 10.1029/2008GL035607
PG 7
WC Geosciences, Multidisciplinary
SC Geology
GA 375VY
UT WOS:000261143100003
ER
PT J
AU Reichardt, J
Reichardt, S
Lin, RF
Hess, M
Mcgee, TJ
Starr, DO
AF Reichardt, J.
Reichardt, S.
Lin, R. -F
Hess, M.
McGee, T. J.
Starr, D. O.
TI Optical-microphysical cirrus model
SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
LA English
DT Article
ID ICE WATER-CONTENT; CRYSTAL TERMINAL VELOCITIES; EFFECTIVE PARTICLE-SIZE;
RADIATIVE PROPERTIES; LIDAR MEASUREMENTS; CLOUD PARTICLES; NATURAL
CLOUDS; ARCTIC CLOUDS; RAMAN LIDAR; SCATTERING
AB A model is presented that permits the simulation of the optical properties of cirrus clouds as measured with depolarization Raman lidars. It comprises a one-dimensional cirrus model with explicit microphysics and an optical module that transforms the microphysical model output to cloud and particle optical properties. The optical model takes into account scattering by randomly oriented or horizontally aligned planar and columnar monocrystals and polycrystals. Key cloud properties such as the fraction of plate-like particles and the number of basic crystals per polycrystal are parameterized in terms of the ambient temperature, the nucleation temperature, or the mass of the particles. The optical-microphysical model is used to simulate the lidar measurement of a synoptically forced cirrostratus in a first case study. It turns out that a cirrus cloud consisting of only monocrystals in random orientation is too simple a model scenario to explain the observations. However, good agreement between simulation and observation is reached when the formation of polycrystals or the horizontal alignment of monocrystals is permitted. Moreover, the model results show that plate fraction and morphological complexity are best parameterized in terms of particle mass, or ambient temperature which indicates that the ambient conditions affect cirrus optical properties more than those during particle formation. Furthermore, the modeled profiles of particle shape and size are in excellent agreement with in situ and laboratory studies, i.e., (partly oriented) polycrystalline particles with mainly planar basic crystals in the cloud bottom layer, and monocrystals above, with the fraction of columns increasing and the shape and size of the particles changing from large thin plates and long columns to small, more isometric crystals from cloud center to top. The findings of this case study corroborate the microphysical interpretation of cirrus measurements with lidar as suggested previously.
C1 [Reichardt, S.] Univ Maryland Baltimore Cty, Joint Ctr Earth Syst Technol, Baltimore, MD 21228 USA.
[Hess, M.] German Aerosp Ctr, Remote Sensing Technol Inst, D-82234 Wessling, Germany.
[Lin, R. -F; Starr, D. O.] NASA, Goddard Space Flight Ctr, Mesoscale Atmospher Proc Branch, Atmospheres Lab, Greenbelt, MD 20771 USA.
[McGee, T. J.] NASA, Goddard Space Flight Ctr, Atmospheres Lab, Atmospher Chem & Dynam Branch, Greenbelt, MD 20771 USA.
RP Reichardt, J (reprint author), Univ Maryland Baltimore Cty, Joint Ctr Earth Syst Technol, Suite 320,5523 Res Pk Drive, Baltimore, MD 21228 USA.
EM sreichardt@aeolus.gsfc.nasa.gov; jens.reichardt@dwd.de;
lin@agnes.gsfc.nasa.gov; michael.hess@dlr.de;
mcgee@aeolus.gsfc.nasa.gov; starr@agnes.gsfc.nasa.gov
RI McGee, Thomas/G-4951-2013
FU European Commission [ENV4-CT95-0162]; German Bundesministerium fur
Bildung; Wissenschaft und Technologie [01LO9504/5]
FX This work was funded by the European Commission (grant ENV4-CT95-0162)
and the German Bundesministerium fur Bildung, Wissenschaft und
Technologie (grant 01LO9504/5). We appreciate the support of Donald
Anderson and Hal Maring of NASA's Radiation Sciences Program.
NR 55
TC 7
Z9 7
U1 1
U2 7
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 2169-897X
J9 J GEOPHYS RES-ATMOS
JI J. Geophys. Res.-Atmos.
PD NOV 18
PY 2008
VL 113
AR D22201
DI 10.1029/2008JD010071
PG 17
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 375WK
UT WOS:000261144300002
ER
PT J
AU Rosolem, R
Shuttleworth, WJ
de Goncalves, LGG
AF Rosolem, Rafael
Shuttleworth, William James
de Goncalves, Luis Gustavo Goncalves
TI Is the data collection period of the Large-Scale Biosphere-Atmosphere
Experiment in Amazonia representative of long-term climatology?
SO JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES
LA English
DT Article
ID TRANSITIONAL TROPICAL FOREST; RAIN-FOREST; SEASONAL-VARIATIONS;
BRAZILIAN AMAZON; CARBON; BASIN; DEFORESTATION; FLUXES; ENERGY; CO2
AB The Large-Scale Biosphere-Atmosphere Experiment in Amazonia (LBA) sampled surface-atmosphere flux exchanges and related ecohydrometeorological processes at several flux tower sites in the Amazonian region between 1999 and 2006. This extensive database is now being analyzed to investigate, for example, the carbon balance of the Amazon basin and the effect of land use change in the basin on climate. It is therefore important to establish whether the period during which these data were collected is representative of the long-term climatology for the region. This study analyzed long-term climate station data for stations located nearby the LBA eddy flux tower sites. Measurements taken during the period of data collection were compared with the long-term station climatology using the Kolmogorov-Smirnov test and analysis of histogram from random samples from the long-term climatological record. In terms of precipitation, the LBA data collection period is statistically consistent with the climatology for all LBA study sites. In terms of temperature, the same result is true for most flux station sites; the main exception being the Bananal Island site where the temperature during the LBA period is significantly warmer by about 1 degrees C. There were some short periods when temperature in the region of other LBA flux sites was also statistically different ( higher) during the LBA data collection period and an average but not statistically significant tendency toward higher temperatures across the whole region during the LBA period relative to previous years. This is probably because there has been significant land cover change near some of the LBA study sites, but a contribution from climate warming cannot be ruled out.
C1 [Rosolem, Rafael; Shuttleworth, William James] Univ Arizona, Dept Hydrol & Water Resources, Tucson, AZ 85721 USA.
[de Goncalves, Luis Gustavo Goncalves] NASA, Goddard Space Flight Ctr, Hydrol Sci Branch, Greenbelt, MD 20771 USA.
RP Rosolem, R (reprint author), Univ Arizona, Dept Hydrol & Water Resources, Tucson, AZ 85721 USA.
EM rafael@hwr.arizona.edu
RI Garcia Bustamante, Elena/H-4188-2012; de Goncalves, Luis
Gustavo/G-2522-2012; Rosolem, Rafael/J-6637-2013;
OI Garcia Bustamante, Elena/0000-0002-2677-0252; Rosolem,
Rafael/0000-0002-4914-692X; de Goncalves, Luis
Gustavo/0000-0002-1571-0916
FU NASA-LBA Ecology [NNX06AG91G]; NSF Center for Sustainability of
semi-Arid Hydrology and Riparian Areas ( SAHRA) [EAR-9876800,
DEB-0415977]
FX This study was supported by the NASA-LBA Ecology ( Group CD36) Project
under grant NNX06AG91G and by the NSF Center for Sustainability of
semi-Arid Hydrology and Riparian Areas ( SAHRA) under the STC Program of
the National Science Foundation agreement EAR-9876800 and NSF award
DEB-0415977. The maps with the location of the LBA eddy flux towers and
the weather stations were kindly provided by Daniel de Castro Victoria
of the Laboratorio de Geoprocessamento e Tratamento de Imagens (
CENA/USP). The authors would like to thank the two anonymous reviewers
for valuable comments that substantially improved the manuscript.
NR 40
TC 5
Z9 5
U1 0
U2 4
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 2169-8953
EI 2169-8961
J9 J GEOPHYS RES-BIOGEO
JI J. Geophys. Res.-Biogeosci.
PD NOV 18
PY 2008
VL 113
AR G00B09
DI 10.1029/2007JG000628
PG 12
WC Environmental Sciences; Geosciences, Multidisciplinary
SC Environmental Sciences & Ecology; Geology
GA 375WS
UT WOS:000261145100001
ER
PT J
AU Volkov, DL
Fu, LL
AF Volkov, Denis L.
Fu, Lee-Lueng
TI The role of vorticity fluxes in the dynamics of the Zapiola Anticyclone
SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
LA English
DT Article
ID ANTARCTIC CIRCUMPOLAR CURRENT; GENERAL-CIRCULATION MODEL; TOPEX/POSEIDON
ALTIMETER; ARGENTINE BASIN; SOUTH-ATLANTIC; OCEAN; VARIABILITY;
TRANSPORT; CURRENTS; VOLUME
AB The Argentine Basin in the South Atlantic Ocean is one of the most energetic regions in the ocean with complicated dynamics, which plays an important role in the global climate. A number of observations have discovered an intense anticyclonic gyre of barotropic circulation around the Zapiola Rise in the center of the basin. Theoretical studies have shown that the Zapiola Anticyclone represents an eddy-driven flow controlled by bottom friction. Recent advances in high-resolution global-ocean data syntheses, performed using NASA supercomputing facilities, provide realistic simulations of the circulation and the variability in the Argentine Basin. Using these simulations and satellite altimeter observations, we analyzed the vorticity balance of the Zapiola Anticyclone. Our results suggest the dominance of vorticity fluxes and the advection of the potential vorticity over a nonuniform bottom topography in determining the variability of the gyre, while the impact of the local wind stress is small. The divergence of the relative vorticity anomaly advection by eddies is found to be the most important contributor to the relative vorticity flux divergence influencing the variability of the Zapiola Anticyclone. Our results demonstrate that the relative vorticity influencing the variability of the anticyclone is mainly advected from the south where the northern branch of the Antarctic Circumpolar Current at the Subpolar Front is located.
C1 [Volkov, Denis L.; Fu, Lee-Lueng] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Volkov, DL (reprint author), CALTECH, Jet Prop Lab, MS 300-314,4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM dvolkov@caltech.edu
RI Volkov, Denis/A-6079-2011
OI Volkov, Denis/0000-0002-9290-0502
FU National Aeronautics and Space Administration (NASA) Modeling, Analysis
and Prediction program
FX The research described in this paper was carried out at the Jet
Propulsion Laboratory, California Institute of Technology, within the
framework of the ECCO2 project sponsored by the National Aeronautics and
Space Administration (NASA) Modeling, Analysis and Prediction program.
We used M_Map mapping package for Matlab developed by Rich Pawlowicz.
The efforts of all members of the ECCO2 group involved in running
model-simulations are appreciated. The first author thanks Dimitris
Menemenlis for helpful discussions. We are thankful to two anonymous
reviewers for their constructive remarks that helped improve the
manuscript.
NR 24
TC 18
Z9 18
U1 0
U2 4
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0148-0227
J9 J GEOPHYS RES-OCEANS
JI J. Geophys. Res.-Oceans
PD NOV 18
PY 2008
VL 113
IS C11
AR C11015
DI 10.1029/2008JC004841
PG 10
WC Oceanography
SC Oceanography
GA 375WZ
UT WOS:000261145800002
ER
PT J
AU Grant, JA
Wilson, SA
Cohen, BA
Golombek, MP
Geissler, PE
Sullivan, RJ
Kirk, RL
Parker, TJ
AF Grant, John A.
Wilson, Sharon A.
Cohen, Barbara A.
Golombek, Matthew P.
Geissler, Paul E.
Sullivan, Robert J.
Kirk, Randolph L.
Parker, Timothy J.
TI Degradation of Victoria crater, Mars
SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS
LA English
DT Article
ID IMPACT CRATERS; MERIDIANI-PLANUM; EJECTA EMPLACEMENT; LANDING SITE;
DEPOSITS; SOILS
AB The similar to 750 m diameter and similar to 75 m deep Victoria crater in Meridiani Planum, Mars, is a degraded primary impact structure retaining a similar to 5 m raised rim consisting of 1-2 m of uplifted rocks overlain by similar to 3 m of ejecta at the rim crest. The rim is 120-220 m wide and is surrounded by a dark annulus reaching an average of 590 m beyond the raised rim. Comparison between observed morphology and that expected for pristine craters 500-750 m across indicates that the original, pristine crater was close to 600 m in diameter. Hence, the crater has been erosionally widened by similar to 150 m and infilled by similar to 50 m of sediments. Eolian processes are responsible for most crater modification, but lesser mass wasting or gully activity contributions cannot be ruled out. Erosion by prevailing winds is most significant along the exposed rim and upper walls and accounts for similar to 50 m widening across a WNW-ESE diameter. The volume of material eroded from the crater walls and rim is similar to 20% less than the volume of sediments partially filling the crater, indicating eolian infilling from sources outside the crater over time. The annulus formed when similar to 1 m deflation of the ejecta created a lag of more resistant hematite spherules that trapped < 10-20 cm of darker, regional basaltic sands. Greater relief along the rim enabled meters of erosion. Comparison between Victoria and regional craters leads to definition of a crater degradation sequence dominated by eolian erosion and infilling over time.
C1 [Grant, John A.; Wilson, Sharon A.] Smithsonian Inst, Natl Air & Space Museum, Ctr Earth & Planetary Studies, Washington, DC 20560 USA.
[Cohen, Barbara A.] NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA.
[Golombek, Matthew P.; Parker, Timothy J.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[Geissler, Paul E.; Kirk, Randolph L.] US Geol Survey, Flagstaff, AZ 86001 USA.
[Sullivan, Robert J.] Cornell Univ, Dept Astron, Ithaca, NY 14853 USA.
RP Grant, JA (reprint author), Smithsonian Inst, Natl Air & Space Museum, Ctr Earth & Planetary Studies, Washington, DC 20560 USA.
EM grantj@si.edu
FU National Aeronautics and Space Administration
FX The authors heartily thank the MER project for their expertise in the
design and operation of such capable rovers. Constructive reviews by Jim
Rice and Brad Thomson helped to improve the paper. The work described
herein was supported by the National Aeronautics and Space
Administration.
NR 49
TC 22
Z9 22
U1 0
U2 8
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0148-0227
J9 J GEOPHYS RES-PLANET
JI J. Geophys. Res.-Planets
PD NOV 18
PY 2008
VL 113
IS E11
AR E11010
DI 10.1029/2008JE003155
PG 16
WC Geochemistry & Geophysics
SC Geochemistry & Geophysics
GA 375XE
UT WOS:000261146300001
ER
PT J
AU McGouldrick, K
Baines, KH
Momary, TW
Grinspoon, DH
AF McGouldrick, K.
Baines, K. H.
Momary, T. W.
Grinspoon, D. H.
TI Venus Express/VIRTIS observations of middle and lower cloud variability
and implications for dynamics
SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS
LA English
DT Article
ID DARK SIDE; GALILEO; FEATURES; CLIMATE; ATMOSPHERE; MORPHOLOGY;
EVOLUTION; FEEDBACK; ORBITER; MISSION
AB We present an analysis of Venus Express Visible and Infrared Thermal Imaging Spectrometer (VIRTIS) data, carried out to characterize the morphological, geographical, and evolutionary trends of the middle and lower cloud features that are observed in the atmosphere of Venus as variations in brightness temperatures in specific near-infrared wavelengths. In this preliminary study, we analyze only data collected over the span of 11 orbits. The mean radiance as a function of latitude is consistent with previous ground-based observations, indicating that the overall global distribution of mean cloud cover is stable, at least on a 10- to 20-year time scale. In contrast with the consistent level of radiance at high latitudes, a significant amount of variability to the radiance exists at lower latitudes, consistent with significant convective activity in the lower and middle cloud decks. The morphology of the holes tends from highly variable orientations of features with aspect ratios of nearly one at low latitudes, to very large aspect ratios and zonally oriented features at higher latitudes. The peak radiance of the holes appears not to demonstrate a latitudinal tendency. There is evidence of more variability to the morphology and radiance of features at lower latitudes. To investigate the evolution of the holes, we examine a sequence of images taken over a 5 h span of a single orbit. If this limited amount of data is representative, then the typical e-folding time scale for the evolution of a hole is about 1 day.
C1 [McGouldrick, K.; Grinspoon, D. H.] Denver Museum Nat & Sci, Dept Space Sci, Denver, CO 80205 USA.
[Baines, K. H.; Momary, T. W.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP McGouldrick, K (reprint author), Denver Museum Nat & Sci, Dept Space Sci, 2001 Colorado Blvd, Denver, CO 80205 USA.
EM kmcgouldrick@dmns.org
FU NASA [NNX07AI61G]
FX We thank two anonymous reviewers for their careful reading of the
manuscript and their suggestions for making this a stronger paper. We
also acknowledge conversations with Colin Wilson, Con Tsang, and Robert
Carlson that have helped to improve the analysis of the data with
respect to the correction for the emission angle. We also thank The
European Space Agency for the opportunity to work with Venus Express. We
thank Pierre Drossart, Giuseppi Piccioni, and the VIRTIS team for their
assistance in enabling us to reduce and analyze the VIRTIS data. A
portion of the work described in this paper was carried out at the Jet
Propulsion Laboratory, Pasadena, California, under contract with NASA.
K. M. and D. H. G. were supported by NASA in support of ESA's Venus
Express mission under grant NNX07AI61G.
NR 34
TC 4
Z9 4
U1 0
U2 1
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0148-0227
J9 J GEOPHYS RES-PLANET
JI J. Geophys. Res.-Planets
PD NOV 18
PY 2008
VL 113
AR E00B14
DI 10.1029/2008JE003113
PG 12
WC Geochemistry & Geophysics
SC Geochemistry & Geophysics
GA 375XC
UT WOS:000261146100002
ER
PT J
AU Asito, AS
Moormann, AM
Kiprotich, C
Ng'ang'a, ZW
Ploutz-Snyder, R
Rochford, R
AF Asito, Amolo S.
Moormann, Ann M.
Kiprotich, Chelimo
Ng'ang'a, Zipporah W.
Ploutz-Snyder, Robert
Rochford, Rosemary
TI Alterations on peripheral B cell subsets following an acute
uncomplicated clinical malaria infection in children
SO MALARIA JOURNAL
LA English
DT Article
ID PLASMODIUM-FALCIPARUM MALARIA; BLOOD-STAGE ANTIGENS; LYMPHOCYTE;
PATTERNS; DIFFERENTIATION; SUBPOPULATIONS; INDIVIDUALS; DISTURBANCE;
ACTIVATION; EXPRESSION
AB Background: The effects of Plasmodium falciparum on B-cell homeostasis have not been well characterized. This study investigated whether an episode of acute malaria in young children results in changes in the peripheral B cell phenotype.
Methods: Using flow-cytofluorimetric analysis, the B cell phenotypes found in the peripheral blood of children aged 2-5 years were characterized during an episode of acute uncomplicated clinical malaria and four weeks post-recovery and in healthy age-matched controls.
Results: There was a significant decrease in CD19(+) B lymphocytes during acute malaria. Characterization of the CD19(+) B cell subsets in the peripheral blood based on expression of IgD and CD38 revealed a significant decrease in the numbers of naive 1 CD38-IgD(+) B cells while there was an increase in CD38(+) IgD- memory 3 B cells during acute malaria. Further analysis of the peripheral B cell phenotype also identified an expansion of transitional CD10(+) CD19(+) B cells in children following an episode of acute malaria with up to 25% of total CD19(+) B cell pool residing in this subset.
Conclusion: Children experiencing an episode of acute uncomplicated clinical malaria experienced profound disturbances in B cell homeostasis.
C1 [Rochford, Rosemary] SUNY Upstate Med Univ, Dept Microbiol & Immunol, Syracuse, NY 13210 USA.
[Asito, Amolo S.; Ng'ang'a, Zipporah W.] Kenyatta Univ, Sch Pure & Appl Sci, Nairobi, Kenya.
[Asito, Amolo S.; Kiprotich, Chelimo] Ctr Global Hlth Res, Kenya Med Res Inst, Kisumu, Kenya.
[Moormann, Ann M.] Case Western Reserve Univ, Ctr Global Hlth & Dis, Cleveland, OH 44106 USA.
[Ploutz-Snyder, Robert] SUNY Upstate Med Univ, Ctr Outcomes Res & Evaluat, Syracuse, NY USA.
[Ploutz-Snyder, Robert] NASA, Human Adaptat & Countermeasures Div, Biostat Lab, Houston, TX USA.
RP Rochford, R (reprint author), SUNY Upstate Med Univ, Dept Microbiol & Immunol, Syracuse, NY 13210 USA.
EM aamolo@kisian.mimcom.net; moorms@case.edu; kchelimo@kisian.mimcom.net;
zipnganga@yahoo.com; robert.ploutz-snyder-1@nasa.gov;
rochforr@upstate.edu
FU NIH [R01 CA102667, K08 AI 51565]
FX This work was done with the permission of the Director of the Kenya
Medical Research Institute. The authors thank the field assistants and
the families for their participation in this study and Dr. Erwan Piriou
for critical reading of the manuscript. The authors thank Bob Balderas (
BD-Pharmingen Inc., La Jolla, CA) for generous donation of antibodies
for this study. This work was supported by NIH R01 CA102667 ( R. R.),
NIH K08 AI 51565 ( A. M.), and the Elizabeth Crosby Award ( R. R.)
NR 28
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Z9 36
U1 0
U2 0
PU BIOMED CENTRAL LTD
PI LONDON
PA 236 GRAYS INN RD, FLOOR 6, LONDON WC1X 8HL, ENGLAND
SN 1475-2875
J9 MALARIA J
JI Malar. J.
PD NOV 18
PY 2008
VL 7
AR 238
DI 10.1186/1475-2875-7-238
PG 8
WC Infectious Diseases; Parasitology; Tropical Medicine
SC Infectious Diseases; Parasitology; Tropical Medicine
GA 409XX
UT WOS:000263540200001
PM 19019204
ER
PT J
AU Cathey, HM
AF Cathey, H. M., Jr.
TI Development overview of the revised NASA Ultra Long Duration Balloon
SO ADVANCES IN SPACE RESEARCH
LA English
DT Article
DE Balloon; ULDB; Ultra Long Duration; Test flight; Pumpkin; Stratosphere
AB The desire for longer duration stratospheric flights at constant float altitudes for heavy payloads has been the focus of the development of the National Aeronautics and Space Administration's (NASA) Ultra Long Duration Balloon (ULDB) effort. Recent efforts have focused on ground testing and analysis to understand the previously observed issue of balloon deployment. A revised approach to the pumpkin balloon design has been tested through ground testing of model balloons and through two test flights. The design approach does not require foreshortening, and will significantly reduce the balloon handling during manufacture reducing the chances of inducing damage to the envelope. Successful ground testing of model balloons lead to the fabrication and test flight of a similar to 176,000 m(3) (similar to 6.2 MCF - Million Cubic Foot) balloon. Pre-flight analytical predictions predicted that the proposed flight balloon design to be stable and should fully deploy. This paper provides an overview of this first test flight of the revised Ultra Long Duration Balloon design which was a short domestic test flight froth Ft. Sumner, NM, USA. This balloon fully deployed, but developed a leak under pressurization. After an extensive investigation to the cause of the leak, a second test flight balloon was fabricated. This similar to 176,000 m(3) (similar to 6.2 MCF) balloon was flown from Kiruna, Sweden in June of 2006. Flight results for both test flights, including flight performance are presented. (C) 2007 COSPAR. Published by Elsevier Ltd. All rights reserved.
C1 NASA, Goddard Space Flight Ctr, New Mexico State Univ,Balloon Program Off, Phys Sci Lab,Wallops Flight Facil, Wallops Isl, VA 23337 USA.
RP Cathey, HM (reprint author), NASA, Goddard Space Flight Ctr, New Mexico State Univ,Balloon Program Off, Phys Sci Lab,Wallops Flight Facil, Code 820,8016 Atlantic Rd, Wallops Isl, VA 23337 USA.
EM henry.m.cathey.1@gsfc.nasa.gov
NR 5
TC 3
Z9 3
U1 0
U2 1
PU ELSEVIER SCI LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND
SN 0273-1177
J9 ADV SPACE RES
JI Adv. Space Res.
PD NOV 17
PY 2008
VL 42
IS 10
BP 1624
EP 1632
DI 10.1016/j.asr.2007.03.026
PG 9
WC Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology &
Atmospheric Sciences
SC Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences
GA 369PE
UT WOS:000260705600002
ER
PT J
AU Hall, JL
Jones, JA
Kerzhanovich, VV
Lachenmeier, T
Mahr, P
Pauken, M
Plett, GA
Smith, L
Van Luvender, ML
Yavrouian, AH
AF Hall, J. L.
Jones, J. A.
Kerzhanovich, V. V.
Lachenmeier, T.
Mahr, P.
Pauken, M.
Plett, G. A.
Smith, L.
Van Luvender, M. L.
Yavrouian, A. H.
TI Experimental results for Titan aerobot thermo-mechanical subsystem
development
SO ADVANCES IN SPACE RESEARCH
LA English
DT Article
DE Balloon; Aerobot; Titan; Mobility; Planetary exploration
AB This paper describes experimental results from a development program focused on maturing Titan aerobot technology in the areas of mechanical and thermal subsystems. Results from four key activities are described: first, a cryogenic balloon materials development program involving coupon and cylinder tests and culminating in the fabrication and testing of an inflated 4.6 m long prototype blimp at 93 K; second, a combined lab experiment and numerical simulation effort to assess potential problems resulting from radioisotope power source waste heat generation near an inflated blimp; third, an aerial deployment and inflation development program consisting of laboratory and helicopter drop tests on a near full scale (11 m long) prototype blimp; and fourth, a proof of concept experiment demonstrating the viability of using a mechanically steerable high gain antenna on a floating blimp to perform direct to Earth telecommunications from Titan. The paper provides details on all of these successful activities and discusses their impact on the overall effort to produce mature systems technology for future Titan aerobot missions. (C) 2007 COSPAR. Published by Elsevier Ltd. All rights reserved.
C1 [Hall, J. L.; Jones, J. A.; Kerzhanovich, V. V.; Pauken, M.; Plett, G. A.; Van Luvender, M. L.; Yavrouian, A. H.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[Lachenmeier, T.] Near Space Corp, Tillamook, OR 97141 USA.
[Mahr, P.; Smith, L.] Lamart Corp, Clifton, NJ 07015 USA.
RP Hall, JL (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM jlhall@pop.jpl.nasa.gov
NR 13
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U1 0
U2 0
PU ELSEVIER SCI LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND
SN 0273-1177
J9 ADV SPACE RES
JI Adv. Space Res.
PD NOV 17
PY 2008
VL 42
IS 10
BP 1641
EP 1647
DI 10.1016/j.asr.2007.02.060
PG 7
WC Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology &
Atmospheric Sciences
SC Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences
GA 369PE
UT WOS:000260705600004
ER
PT J
AU Hall, JL
Fairbrother, D
Frederickson, T
Kerzhanovich, VV
Said, M
Sandy, C
Ware, J
Willey, C
Yavrouian, AH
AF Hall, J. L.
Fairbrother, D.
Frederickson, T.
Kerzhanovich, V. V.
Said, M.
Sandy, C.
Ware, J.
Willey, C.
Yavrouian, A. H.
TI Prototype design and testing of a Venus long duration, high altitude
balloon
SO ADVANCES IN SPACE RESEARCH
LA English
DT Article
DE Balloon; Aerobot; Venus; Mobility
AB This paper describes the design, fabrication and testing of a full scale prototype balloon intended for long duration flight in the upper atmosphere of Venus. The balloon is 5.5 m diameter and is designed to carry a 45 kg payload at an altitude of 55 km. The balloon material is a 180 g/m(2) multi-component laminate comprised of the following layers bonded together from outside to inside: aluminized Teflon film, aluminized Mylar film. Vectran fabric and a polyurethane coating. This construction provides the required balloon functional characteristics of low gas permeability, sulfuric acid resistance and high strength for superpressure operation. The design burst superpressure is 39,200 Pa which is predicted to be 3.3 times the worst case value expected during flight at the highest solar irradiance in the mission profile. The prototype is constructed from 16 gores with bi-taped seams employing a sulfuric acid resistant adhesive on the outside. Material coupon tests were performed to evaluate the optical and mechanical characteristics of the laminate. These were followed by full prototype tests for inflation, leakage and sulfuric acid tolerance. The results confirmed the suitability of this balloon design for use at Venus in a long duration mission. The various data are presented and the implications for mission design and operation are discussed. (C) 2007 COSPAR. Published by Elsevier Ltd. All rights reserved.
C1 [Hall, J. L.; Kerzhanovich, V. V.; Yavrouian, A. H.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[Fairbrother, D.; Said, M.] NASA, Wallops Flight Facil, Wallops Isl, VA USA.
[Frederickson, T.; Sandy, C.; Ware, J.; Willey, C.] ILC Dover Inc, Frederica, DE 19946 USA.
RP Hall, JL (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM jlhall@pop.jpl.nasa.gov
FU Jet Propulsion Laboratory; California Institute of Technology; National
Aeronautics and Space Administration; NASA Wallops Flight Facility; ILC
Dover, Inc
FX The research described in this paper was funded by the Jet Propulsion
Laboratory, California Institute of Technology, under a contract with
the National Aeronautics and Space Administration. Additional test
support funds were provided by NASA Wallops Flight Facility and ILC
Dover, Inc. The authors thank the following individuals for their
assistance with the work reported therein: Gary Plett, Mike Pauken and
Earl Scott of JPL and Dave Puckett and Molly Powell of NASA GSFC. We
also thank the Jeffrey Cornish, Richard Williamson and Rob Manning from
the Mars Exploration Program for their help in getting us the flight
surplus Vectran fabric used in the prototype.
NR 3
TC 5
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U1 0
U2 5
PU ELSEVIER SCI LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND
SN 0273-1177
J9 ADV SPACE RES
JI Adv. Space Res.
PD NOV 17
PY 2008
VL 42
IS 10
BP 1648
EP 1655
DI 10.1016/j.asr.2007.03.017
PG 8
WC Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology &
Atmospheric Sciences
SC Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences
GA 369PE
UT WOS:000260705600005
ER
PT J
AU Seo, ES
Ahn, HS
Allison, P
Bagliesi, MG
Barbier, L
Barrau, A
Bazer-Bachi, R
Beatty, JJ
Bigongiari, G
Boyle, P
Brandt, TJ
Buenerd, M
Childers, JT
Conklin, NB
Coutu, S
Derome, L
DuVernois, MA
Ganel, O
Han, JH
Jeon, JA
Kim, KC
Lee, MH
Lutz, L
Malinin, A
Mangin-Brinet, M
Marrocchesi, PS
Maestro, P
Menchaca-Rocha, A
Minnick, S
Mognet, SI
Nam, S
Nutter, S
Park, IH
Park, NH
Putze, A
Sina, R
Swordy, S
Wakely, S
Walpole, P
Wu, J
Yang, J
Yoon, YS
Zei, R
Zinn, SY
AF Seo, E. S.
Ahn, H. S.
Allison, P.
Bagliesi, M. G.
Barbier, L.
Barrau, A.
Bazer-Bachi, R.
Beatty, J. J.
Bigongiari, G.
Boyle, P.
Brandt, T. J.
Buenerd, M.
Childers, J. T.
Conklin, N. B.
Coutu, S.
Derome, L.
DuVernois, M. A.
Ganel, O.
Han, J. H.
Jeon, J. A.
Kim, K. C.
Lee, M. H.
Lutz, L.
Malinin, A.
Mangin-Brinet, M.
Marrocchesi, P. S.
Maestro, P.
Menchaca-Rocha, A.
Minnick, S.
Mognet, S. I.
Nam, S.
Nutter, S.
Park, I. H.
Park, N. H.
Putze, A.
Sina, R.
Swordy, S.
Wakely, S.
Walpole, P.
Wu, J.
Yang, J.
Yoon, Y. S.
Zei, R.
Zinn, S. Y.
TI CREAM: 70 days of flight from 2 launches in Antarctica
SO ADVANCES IN SPACE RESEARCH
LA English
DT Article
DE Cosmic rays; ULDB; CREAM; Balloon experiment; Antarctica
ID COSMIC-RAYS; CHARGE DETECTOR; ENERGY-SPECTRA
AB The Cosmic-Ray Energetics And Mass balloon-borne experiment has been launched twice in Antarctica, first in December 2004 and again in December 2005. It circumnavigated the South Pole three times during the first flight, which set a flight duration record of 42 days. A cumulative duration of 70 days within 13 months was achieved when the second flight completed 28 days during two circumnavigations of the Pole on 13 January 2006. Both the science instrument and support systems functioned extremely well, and a total 117 GB of data including 67 million science events were collected during these two flights. Preliminary analysis indicates that the data extend well above 100 TeV and follow reasonable power laws. The payload recovered from the first flight has been refurbished for the third flight in 2007, whereas the payload from the second flight is being refurbished to be ready for the fourth flight in 2008. Each flight will extend the reach of precise cosmic-ray composition measurements to energies not previously possible. (C) 2007 COSPAR. Published by Elsevier Ltd. All rights reserved.
C1 [Seo, E. S.; Ahn, H. S.; Ganel, O.; Han, J. H.; Kim, K. C.; Lee, M. H.; Lutz, L.; Malinin, A.; Sina, R.; Walpole, P.; Wu, J.; Zinn, S. Y.] Univ Maryland, Inst Phys Sci & Technol, College Pk, MD 20742 USA.
[Seo, E. S.; Yoon, Y. S.] Univ Maryland, Dept Phys, College Pk, MD 20742 USA.
[Allison, P.; Beatty, J. J.; Brandt, T. J.] Ohio State Univ, Dept Phys, Columbus, OH 43210 USA.
[Bagliesi, M. G.; Marrocchesi, P. S.; Maestro, P.; Zei, R.] Univ Siena, Dept Phys, I-53100 Siena, Italy.
[Bagliesi, M. G.; Marrocchesi, P. S.; Maestro, P.] Ist Nazl Fis Nucl, I-53100 Siena, Italy.
[Barbier, L.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
[Barrau, A.; Buenerd, M.; Derome, L.; Mangin-Brinet, M.; Putze, A.] Lab Phys Subatom & Cosmol, Grenoble, France.
[Bazer-Bachi, R.] Ctr Etud Spatiale Rayonnements, CNRS, UFR PCA, UPR 8002, Toulouse, France.
[Boyle, P.; Swordy, S.; Wakely, S.] Univ Chicago, Enrico Fermi Inst, Chicago, IL 60637 USA.
[Boyle, P.; Swordy, S.; Wakely, S.] Univ Chicago, Dept Phys, Chicago, IL 60637 USA.
[Childers, J. T.; DuVernois, M. A.] Univ Minnesota, Sch Phys & Astron, Minneapolis, MN 55455 USA.
[Conklin, N. B.; Coutu, S.; Mognet, S. I.] Penn State Univ, Dept Phys, University Pk, PA 16802 USA.
[Jeon, J. A.; Nam, S.; Park, I. H.; Park, N. H.; Yang, J.] Ewha Womans Univ, Dept Phys, Seoul 120750, South Korea.
[Menchaca-Rocha, A.] Univ Nacl Autonoma Mexico, Inst Fis, Mexico City 04510, DF, Mexico.
[Minnick, S.] Kent State Univ Tuscarawas, Dept Phys, New Philadelphia, OH 44663 USA.
[Nutter, S.] No Kentucky Univ, Dept Phys & Geol, Highland Hts, KY 41099 USA.
RP Seo, ES (reprint author), Univ Maryland, Inst Phys Sci & Technol, College Pk, MD 20742 USA.
EM seo@umd.edu
RI maestro, paolo/E-3280-2010; Marrocchesi, Pier Simone/N-9068-2015; Yoon,
Young Soo/O-8580-2014; Beatty, James/D-9310-2011;
OI maestro, paolo/0000-0002-4193-1288; Marrocchesi, Pier
Simone/0000-0003-1966-140X; Yoon, Young Soo/0000-0001-7023-699X; Beatty,
James/0000-0003-0481-4952; Bigongiari, Gabriele/0000-0003-3691-0826;
Seo, Eun-Suk/0000-0001-8682-805X
FU NASA; Korean Ministry of Science and Technology in Korea; NASA/WFF;
Columbia Scientific Balloon Facility; National Science Foundation Office
of Polar Programs; Raytheon Polar Service Company
FX This work is supported by NASA grants in the US, by the Korean Ministry
of Science and Technology in Korea, by INFN in Italy, and by IN2P3 in
France. The authors thank NASA/WFF, Columbia Scientific Balloon
Facility, National Science Foundation Office of Polar Programs, and
Raytheon Polar Service Company for the successful balloon launch, flight
operations, and payload recovery.
NR 23
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PU ELSEVIER SCI LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND
SN 0273-1177
EI 1879-1948
J9 ADV SPACE RES
JI Adv. Space Res.
PD NOV 17
PY 2008
VL 42
IS 10
BP 1656
EP 1663
DI 10.1016/j.asr.2007.03.056
PG 8
WC Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology &
Atmospheric Sciences
SC Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences
GA 369PE
UT WOS:000260705600006
ER
PT J
AU Yoshimura, K
Abe, K
Fuke, H
Haino, S
Hams, T
Hasegawa, M
Horikoshi, A
Kim, KC
Kumazawa, T
Kusumoto, A
Lee, MH
Makida, Y
Matsuda, S
Matsukawa, Y
Mitchell, JW
Moiseev, AA
Nishimura, J
Nozaki, M
Orito, R
Ormes, JF
Sakai, K
Sasaki, M
Seo, ES
Shikaze, Y
Shinoda, R
Streitmatter, RE
Suzuki, J
Takeuchi, K
Thakur, N
Tanaka, K
Yamagami, T
Yamamoto, A
Yoshida, T
AF Yoshimura, K.
Abe, K.
Fuke, H.
Haino, S.
Hams, T.
Hasegawa, M.
Horikoshi, A.
Kim, K. C.
Kumazawa, T.
Kusumoto, A.
Lee, M. -H.
Makida, Y.
Matsuda, S.
Matsukawa, Y.
Mitchell, J. W.
Moiseev, A. A.
Nishimura, J.
Nozaki, M.
Orito, R.
Ormes, J. F.
Sakai, K.
Sasaki, M.
Seo, E. S.
Shikaze, Y.
Shinoda, R.
Streitmatter, R. E.
Suzuki, J.
Takeuchi, K.
Thakur, N.
Tanaka, K.
Yamagami, T.
Yamamoto, A.
Yoshida, T.
TI BESS-Polar experiment: Progress and future prospects
SO ADVANCES IN SPACE RESEARCH
LA English
DT Article
DE Superconducting spectrometer; BESS; Long-duration balloon flight;
Antarctica
ID ANTARCTICA; FLIGHTS; SEARCH
AB The first scientific flight of the BESS-Polar balloon-borne experiment was successfully carried out in December 2004 from Antarctica with the primary scientific objectives of searching for primordial antiparticles from the universe and making precision measurements of primary cosmic-ray fluxes. During the 8.5 day flight, the newly developed BESS-Polar spectrometer worked well and gathered data from 9 x 10(8) cosmic-ray events, showing its capability for making long-duration science observations. We have already started hardware development for the second experiment, which is expected to be a flight of more than 20 days during the next solar minimum period with the upgraded spectrometer. In this manuscript, progress on and prospects for the BESS-Polar experiment are described. (C) 2008 Published by Elsevier Ltd on behalf of COSPAR.
C1 [Yoshimura, K.; Abe, K.; Haino, S.; Hasegawa, M.; Horikoshi, A.; Kumazawa, T.; Makida, Y.; Matsuda, S.; Nozaki, M.; Suzuki, J.; Tanaka, K.; Yamamoto, A.] High Energy Accelerator Res Org KEK, Tsukuba, Ibaraki 3050801, Japan.
[Kusumoto, A.; Matsukawa, Y.; Orito, R.; Shikaze, Y.; Takeuchi, K.] Kobe Univ, Kobe, Hyogo 6578501, Japan.
[Fuke, H.; Yamagami, T.; Yoshida, T.] Japan Aerosp Explorat Agcy, Inst Space & Astronaut Sci, Sagamihara, Kanagawa 2298510, Japan.
[Hams, T.; Mitchell, J. W.; Moiseev, A. A.; Sasaki, M.; Streitmatter, R. E.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
[Kim, K. C.; Lee, M. -H.; Seo, E. S.] Univ Maryland, College Pk, MD 20742 USA.
[Nishimura, J.; Shinoda, R.] Univ Tokyo, Tokyo 1130033, Japan.
[Ormes, J. F.; Thakur, N.] Univ Denver, Denver, CO 80208 USA.
RP Yoshimura, K (reprint author), High Energy Accelerator Res Org KEK, Tsukuba, Ibaraki 3050801, Japan.
EM koji.yoshimura@kek.jp
OI Seo, Eun-Suk/0000-0001-8682-805X
NR 13
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U1 0
U2 5
PU ELSEVIER SCI LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND
SN 0273-1177
J9 ADV SPACE RES
JI Adv. Space Res.
PD NOV 17
PY 2008
VL 42
IS 10
BP 1664
EP 1669
DI 10.1016/j.asr.2007.05.048
PG 6
WC Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology &
Atmospheric Sciences
SC Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences
GA 369PE
UT WOS:000260705600007
ER
PT J
AU Zhou, XY
Lummerzheim, D
Gladstone, GR
Gunapala, SD
Bandara, SB
Trihne, J
Herrell, L
AF Zhou, X. -Y.
Lummerzheim, D.
Gladstone, G. R.
Gunapala, S. D.
Bandara, S. B.
Trihne, J.
Herrell, L.
TI Magnetospheric application of high-altitude long-duration balloon
technology: Daylight auroral observations
SO ADVANCES IN SPACE RESEARCH
LA English
DT Article
DE Aurora; Auroral observations; Balloon technology; Magnetospheric
application
ID X-RAYS; ELECTRON-PRECIPITATION; PRESSURE PULSES; SIMULATION; FIELD;
ZONE; CONDUCTIVITY; STRATOSPHERE; IONOSPHERE
AB Daylight auroral imaging is a proposed application of the NASA high-altitude long-duration balloon technology. This paper discusses the theoretical background of this application and test observations, for proof of the feasibility. It is demonstrated that nitrogen auroral emissions in the near-infrared band are detectable Lit altitudes of 35-40 km and above using a near-infrared InGaAs camera. The purpose of such observations is to identify auroral small-scale structures that are manifestations of auroral particle accelerations and the solar wind - magnetosphere - ionosphere interaction. Use of this new approach will enable studies of the dayside aurora, low-latitude aurora, and storm-time and substorm-time auroral conjugacy. (C) 2007 COSPAR. Published by Elsevier Ltd. All rights reserved.
C1 [Zhou, X. -Y.; Gunapala, S. D.; Bandara, S. B.; Trihne, J.; Herrell, L.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[Lummerzheim, D.] Univ Alaska, Fairbanks, AK 99775 USA.
[Gladstone, G. R.] SW Res Inst, San Antonio, TX 78228 USA.
RP Zhou, XY (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM xiaoyan.zhou@jpl.nasa.gov
NR 34
TC 3
Z9 3
U1 0
U2 1
PU ELSEVIER SCI LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND
SN 0273-1177
J9 ADV SPACE RES
JI Adv. Space Res.
PD NOV 17
PY 2008
VL 42
IS 10
BP 1676
EP 1682
DI 10.1016/j.asr.2007.02.034
PG 7
WC Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology &
Atmospheric Sciences
SC Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences
GA 369PE
UT WOS:000260705600009
ER
PT J
AU Thompson, LD
Stuchlik, DW
AF Thompson, L. D.
Stuchlik, D. W.
TI Balloon support systems performance for the cosmic rays energetics and
mass mission
SO ADVANCES IN SPACE RESEARCH
LA English
DT Article
DE Balloon; CREAM; Support system; WFF
AB The Ballooncraft Support Systems were developed by NASA Wallops Flight Facility for use on ULDB class balloon missions. The support systems have now flown two missions supporting the Cosmic Rays Energetics and Mass (CREAM) experiment. The first, CREAM I, flown in December 2004, was for a record breaking 41 days, 21 h, and the second flight flown in December 2005, was for 28 days, 9 h. These support systems provide CREAM with power, telecommunications, command, and data handling including flight computers, mechanical structures, thermal management, and attitude control to help ensure a successful scientific mission. This paper addresses the performance and success of these support systems over the two missions. Published by Elsevier Ltd. on behalf of COSPAR.
C1 [Thompson, L. D.; Stuchlik, D. W.] NASA, Wallops Flight Facil, Balloon Program Off, Wallops Isl, VA 23337 USA.
RP Thompson, LD (reprint author), NASA, Wallops Flight Facil, Balloon Program Off, Code 840, Wallops Isl, VA 23337 USA.
EM lindia.d.thompson@nasa.gov
FU Columbia Scientific Balloon Facility (CSBF); CREAM
FX The authors acknowledge and thank NASA's management who supported the
development and implementation of this new capability, and the NASA
civil servants and contractors on the project team who dedicated
themselves to delivering and supporting a system with world-class
quality. Acknowledgment and thanks are also extended to the science team
who developed and delivered an instrument capable of cutting-edge
science discoveries, and who worked diligently with the project team to
make the flights a reality. And lastly, our appreciation is extended to
the Columbia Scientific Balloon Facility (CSBF) for their expertise in
launching the balloon supporting the CREAM experiment.
NR 0
TC 1
Z9 1
U1 0
U2 1
PU ELSEVIER SCI LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND
SN 0273-1177
J9 ADV SPACE RES
JI Adv. Space Res.
PD NOV 17
PY 2008
VL 42
IS 10
BP 1698
EP 1703
DI 10.1016/j.asr.2007.11.034
PG 6
WC Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology &
Atmospheric Sciences
SC Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences
GA 369PE
UT WOS:000260705600012
ER
PT J
AU Cavalie, O
Lasserre, C
Doin, MP
Peltzer, G
Sun, J
Xu, X
Shen, ZK
AF Cavalie, O.
Lasserre, C.
Doin, M. -P.
Peltzer, G.
Sun, J.
Xu, X.
Shen, Z. -K.
TI Measurement of interseismic strain across the Haiyuan fault (Gansu,
China), by InSAR
SO EARTH AND PLANETARY SCIENCE LETTERS
LA English
DT Article
DE InSAR; active tectonics; fault creep; interseismic deformation;
atmospheric phase propagation delays; Haiyuan fault; Asia
ID SAN-ANDREAS FAULT; MANYI TIBET EARTHQUAKE; NORTH ANATOLIAN FAULT;
ALTYN-TAGH FAULT; RADAR INTERFEROMETRY; CRUSTAL DEFORMATION; CENTRAL
CALIFORNIA; SLIP RATE; PLATEAU; SYSTEM
AB The Haiyuan fault is part of a major left-lateral fault system at the northeastern edge of the Tibet-Qinghai plateau. Two M8 earthquakes (1920 and 1927) occurred along the fault, bracketing an unbroken section of the fault identified as the Tianzhu seismic gap. We use interferometric synthetic aperture radar data from descending orbits of the ERS satellites, acquired between 1993 and 1998 along two adjacent tracks covering the gap, to measure the current surface movements and better understand the present day mechanical behavior of this fault section. The analysis of the radar data involves first the combined correction of orbital errors and errors associated with the phase delay through the troposphere. A subset of the data is then selected based on the analysis of the residual noise spectra for each pair of data. The selected interferograms are stacked and the average phase change rate is converted in fault-parallel velocity assuming that the ground movement is horizontal and parallel to the fault. Velocity maps from both tracks show a zone of high velocity gradient across the fault, a few kilometers wide, consistent with left-lateral slip on the Haiyuan fault. The average velocity field from the two tracks in their overlapping area is well fit with a single screw dislocation model in an elastic half-space. The derived fault slip rate at depth (4.2-8 mm/yr) is consistent with recent GPS results. The corresponding shallow apparent locking depth (0-4.2 km) can be explained by a current low stress accumulation on the fault due to creep almost on the entire fault plane. However, unless it is transient, this creep Would be paradoxical with the occurrence of past large earthquakes along this fault section, as revealed by paleoseismology. An alternative model, implying both shallow creep in the brittle upper crust and deep aseismic slip beneath the seismogenic layer, separated by a locked section, would be consistent with InSAR observations and with the potential for large earthquakes on the fault as well. A two-dislocation model with slip at 5 mm/yr beneath 15 km and a transient creep rate of 11 mm/yr between 2 and 7 km fits the InSAR data. However, the width and creep rate of the shallow creeping zone and their possible along-strike variations are still poorly resolved with the present data set. (c) 2008 Elsevier B.V. All rights reserved.
C1 [Cavalie, O.; Lasserre, C.; Doin, M. -P.] Ecole Normale Super, CNRS, Geol Lab, F-75231 Paris 05, France.
[Peltzer, G.; Shen, Z. -K.] Univ Calif Los Angeles, Dept Earth & Space Sci, Los Angeles, CA 90025 USA.
[Peltzer, G.] CALTECH, Jet Prop Lab, Pasadena, CA USA.
[Sun, J.; Xu, X.] Chinese Earthquake Adm, Inst Geol, Beijing 100029, Peoples R China.
RP Cavalie, O (reprint author), Ecole Normale Super, CNRS, Geol Lab, 24 Rue Lhomond, F-75231 Paris 05, France.
EM cavalieo@ujf-grenoble.fr; cecile.lasserre@ujf-grenoble.fr;
doin@geologie.ens.fr; peltzer@ess.ucla.edu
RI Lasserre, Cecile/D-7073-2017
OI Lasserre, Cecile/0000-0002-0582-0775
FU European Space Agency [ID 2509]; Association Franco-Chinoise pour la
Recherche Scientifique et Technique [T04/04]; Programme National de
Teledetection Spatiale; NASA
FX ERS data were provided by the European Space Agency under the Dragon
project (ID 2509). This collaborative work was partly funded by the
Association Franco-Chinoise pour la Recherche Scientifique et Technique
(PRA project T04/04, C. Lasserre and Z.-K. Shen) and the Programme
National de Teledetection Spatiale. Gilles Peltzer's contribution was
done in part at the jet Propulsion Laboratory under contract with NASA.
We thank two anonymous reviewers, Paul Lundgren, Roland Burgmann and the
associate editor, whose comments greatly improved the manuscript.
NR 56
TC 65
Z9 72
U1 1
U2 17
PU ELSEVIER SCIENCE BV
PI AMSTERDAM
PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS
SN 0012-821X
EI 1385-013X
J9 EARTH PLANET SC LETT
JI Earth Planet. Sci. Lett.
PD NOV 15
PY 2008
VL 275
IS 3-4
BP 246
EP 257
DI 10.1016/j.epsl.2008.07.057
PG 12
WC Geochemistry & Geophysics
SC Geochemistry & Geophysics
GA 380SB
UT WOS:000261484400005
ER
PT J
AU Zeng, T
Wang, YH
Yoshida, Y
Tian, D
Russell, AG
Barnard, WR
AF Zeng, Tao
Wang, Yuhang
Yoshida, Yasuko
Tian, Di
Russell, Amistead G.
Barnard, William R.
TI Impacts of Prescribed Fires on Air Quality over the Southeastern United
States in Spring Based on Modeling and Ground/Satellite Measurements
SO ENVIRONMENTAL SCIENCE & TECHNOLOGY
LA English
DT Article
ID MODIS DATA; AEROSOL; OZONE; EMISSIONS; ALGORITHM; ATLANTIC
AB Prescribed burning is a large aerosol source in the southeastern United States. Its air quality impact is investigated using 3-D model simulations and analysis of ground and satellite observations. Fire emissions for 2002 are calculated based on a recently developed VISTAS emission inventory. March was selected for the investigation because it is the most active prescribed fire month. Inclusion of fire emissions significantly improved model performance. Model results show that prescribed fire emissions lead to similar to 50% enhancements of mean OC and EC concentrations in the Southeast and a daily increase of PM2.5 up to 25 mu g m(-3), indicating that fire emissions can lead to PM2.5 nonattainment in affected regions. Surface enhancements of CO up to 200 ppbv are found. Fire count measurements from the moderate resolution imaging spectroradiometer (MODIS) onboard the NASA Terra satellite show large springtime burning in most states, which is consistent with the emission inventory. These measurements also indicate that the inventory may underestimate fire emissions in the summer.
C1 [Zeng, Tao; Wang, Yuhang] Georgia Inst Technol, Sch Earth & Atmospher Sci, Atlanta, GA 30313 USA.
[Yoshida, Yasuko] Univ Maryland, Goddard Earth Sci & Technol Ctr, Greenbelt, MD 20771 USA.
[Yoshida, Yasuko] NASA, Goddard Space Flight Ctr, Atmospher Chem & Dynam Branch, Greenbelt, MD 20771 USA.
[Tian, Di] Georgia Dept Nat Resources, Environm Protect Div, Atlanta, GA 30354 USA.
[Russell, Amistead G.] Georgia Inst Technol, Sch Civil & Environm Engn, Atlanta, GA 30313 USA.
[Barnard, William R.] MACTEC Engn & Consulting Inc, Newberry, FL 32669 USA.
RP Zeng, T (reprint author), Georgia Inst Technol, Sch Earth & Atmospher Sci, Atlanta, GA 30313 USA.
EM tzeng@eas.gatech.edu
RI Wang, Yuhang/B-5578-2014
FU U.S. EPA [2004-STAR-L1, RD-83227601, RD83096001, RD82897602,
RD83107601]; U.S. Department of Agriculture Air Quality Program
[2007-55112-178055]
FX This work was funded by the U.S. EPA 2004-STAR-L1 Program (grant
RD-83227601), U.S. EPA grants (RD83096001, RD82897602 and RD83107601),
and U.S. Department of Agriculture Air Quality Program (grant
2007-55112-178055).
NR 30
TC 13
Z9 13
U1 0
U2 11
PU AMER CHEMICAL SOC
PI WASHINGTON
PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA
SN 0013-936X
EI 1520-5851
J9 ENVIRON SCI TECHNOL
JI Environ. Sci. Technol.
PD NOV 15
PY 2008
VL 42
IS 22
BP 8401
EP 8406
DI 10.1021/es800363d
PG 6
WC Engineering, Environmental; Environmental Sciences
SC Engineering; Environmental Sciences & Ecology
GA 372SF
UT WOS:000260921400037
PM 19068824
ER
PT J
AU Gonzalez, WD
Echer, E
Tsurutani, BT
AF Gonzalez, W. D.
Echer, E.
Tsurutani, B. T.
TI Reply to comment by C. Cid, E. Saiz, and Y. Cerrato on "Interplanetary
conditions leading to superintense geomagnetic storms (Dst <=-250 nT)
during solar cycle 23''
SO GEOPHYSICAL RESEARCH LETTERS
LA English
DT Editorial Material
ID MAGNETIC STORMS
C1 [Gonzalez, W. D.; Echer, E.] Inst Nacl Pesquisas Espaciais, Div Geofis Espacial, BR-12227010 Sao Jose Dos Campos, SP, Brazil.
[Tsurutani, B. T.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Gonzalez, WD (reprint author), Inst Nacl Pesquisas Espaciais, Div Geofis Espacial, CP 515,Ave Astronautas 1758, BR-12227010 Sao Jose Dos Campos, SP, Brazil.
EM eecher@dge.inpe.br
NR 11
TC 0
Z9 0
U1 0
U2 1
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0094-8276
J9 GEOPHYS RES LETT
JI Geophys. Res. Lett.
PD NOV 15
PY 2008
VL 35
IS 21
AR L21108
DI 10.1029/2008GL035164
PG 3
WC Geosciences, Multidisciplinary
SC Geology
GA 373RZ
UT WOS:000260991500004
ER
PT J
AU Santer, BD
Thorne, PW
Haimberger, L
Taylor, KE
Wigley, TML
Lanzante, JR
Solomon, S
Free, M
Gleckler, PJ
Jones, PD
Karl, TR
Klein, SA
Mears, C
Nychka, D
Schmidt, GA
Sherwood, SC
Wentz, FJ
AF Santer, B. D.
Thorne, P. W.
Haimberger, L.
Taylor, K. E.
Wigley, T. M. L.
Lanzante, J. R.
Solomon, S.
Free, M.
Gleckler, P. J.
Jones, P. D.
Karl, T. R.
Klein, S. A.
Mears, C.
Nychka, D.
Schmidt, G. A.
Sherwood, S. C.
Wentz, F. J.
TI Consistency of modelled and observed temperature trends in the tropical
troposphere
SO INTERNATIONAL JOURNAL OF CLIMATOLOGY
LA English
DT Article
DE tropospheric temperature changes; climate model evaluation; statistical
significance of trend differences; tropical lapse rates; differential
warming of surface and temperature
ID SEA-SURFACE-TEMPERATURE; AIR-TEMPERATURE; CLIMATE MODEL; TIME-SERIES;
RADIOSONDE; HOMOGENIZATION; UNCERTAINTIES; ATMOSPHERE; BIASES;
SENSITIVITIES
AB A recent report of the U.S. Climate Change Science Program (CCSP) identified a 'potentially serious inconsistency' between modelled and observed trends in tropical lapse rates (Karl et al., 2006). Early versions of Satellite and radiosonde datasets suggested that the tropical surface had warmed more than the troposphere, while climate models consistently showed tropospheric amplification of surface warming in response to human-caused increases in well-mixed greenhouse gases (GHGs). We revisit such comparisons here using new observational estimates of surface and tropospheric temperature changes. We find that there is no longer a serious discrepancy between modelled and observed trends in tropical lapse rates.
This emerging reconciliation of models and observations has two primary explanations. First, because of changes in the treatment of buoy and satellite information, new surface temperature datasets yield slightly reduced tropical warming relative to earlier versions. Second, recently developed satellite and radiosonde datasets show larger warming of the tropical lower troposphere. In the case of a new satellite dataset from Remote Sensing Systems (RSS), enhanced warming is due to an improved procedure of adjusting for inter-satellite biases. When the RSS-derived tropospheric temperature trend is compared with four different observed estimates of surface temperature change, the surface warming is invariably amplified in the tropical troposphere, consistent with model results. Even if we use data from a second satellite dataset with smaller tropospheric warming than in RSS, observed tropical lapse rate trends are not significantly different from those in all other model simulations.
Our results contradict a recent claim that all simulated temperature trends in the tropical troposphere and in tropical lapse rates are inconsistent with observations. This claim was based on use of older radiosonde and satellite datasets, and on two methodological errors: the neglect of observational trend uncertainties introduced by interannual climate variability, and application of an inappropriate statistical 'consistency test'. Copyright (c) 2008 Royal Meteorological Society
C1 [Santer, B. D.; Taylor, K. E.; Gleckler, P. J.; Klein, S. A.] Lawrence Livermore Natl Lab, PCMDI, Livermore, CA 94550 USA.
[Thorne, P. W.] Hadley Ctr, UK Meteorol Off, Exeter EX1 3PB, Devon, England.
[Haimberger, L.] Univ Vienna, Dept Meteorol & Geophys, A-1090 Vienna, Austria.
[Wigley, T. M. L.; Nychka, D.] Natl Ctr Atmospher Res, Boulder, CO 80307 USA.
[Lanzante, J. R.] Natl Ocean & Atmospher Adm, Geophys Fluid Dynam Lab, Princeton, NJ 08542 USA.
[Solomon, S.] Natl Ocean & Atmospher Adm, Earth Syst Res Lab, Div Chem Sci, Boulder, CO 80305 USA.
[Free, M.] NOAA, Air Resources Lab, Silver Spring, MD 20910 USA.
[Jones, P. D.] Univ E Anglia, Sch Environm Sci, Climat Res Unit, Norwich NR4 7TJ, Norfolk, England.
[Karl, T. R.] Natl Ocean & Atmospher Adm, Natl Climat Data Ctr, Asheville, NC 28801 USA.
[Mears, C.; Wentz, F. J.] Remote Sensing Syst, Santa Rosa, CA 95401 USA.
[Schmidt, G. A.] NASA, Goddard Inst Space Studies, New York, NY 10025 USA.
[Sherwood, S. C.] Yale Univ, New Haven, CT 06520 USA.
RP Santer, BD (reprint author), Lawrence Livermore Natl Lab, PCMDI, Livermore, CA 94550 USA.
EM santer1@llnl.gov
RI Sherwood, Steven/B-5673-2008; Jones, Philip/C-8718-2009; Taylor,
Karl/F-7290-2011; Santer, Benjamin/F-9781-2011; Schmidt,
Gavin/D-4427-2012; Thorne, Peter/F-2225-2014; Klein,
Stephen/H-4337-2016; Manager, CSD Publications/B-2789-2015
OI Sherwood, Steven/0000-0001-7420-8216; Jones, Philip/0000-0001-5032-5493;
Taylor, Karl/0000-0002-6491-2135; Schmidt, Gavin/0000-0002-2258-0486;
Thorne, Peter/0000-0003-0485-9798; Klein, Stephen/0000-0002-5476-858X;
NR 71
TC 119
Z9 122
U1 2
U2 39
PU WILEY-BLACKWELL
PI HOBOKEN
PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA
SN 0899-8418
EI 1097-0088
J9 INT J CLIMATOL
JI Int. J. Climatol.
PD NOV 15
PY 2008
VL 28
IS 13
BP 1703
EP 1722
DI 10.1002/joc.1756
PG 20
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 373WE
UT WOS:000261003400002
ER
PT J
AU Ye, ZQ
Hsieh, WW
AF Ye, Zhengqing
Hsieh, William W.
TI Changes in ENSO and Associated Overturning Circulations from Enhanced
Greenhouse Gases by the End of the Twentieth Century
SO JOURNAL OF CLIMATE
LA English
DT Article
ID COUPLED CLIMATE MODELS; EL-NINO-LIKE; DECADAL VARIABILITY; TROPICAL
OCEAN; MULTIMODEL ENSEMBLE; PACIFIC-OCEAN; TRENDS; CYCLE
AB With data from 12 coupled models in the Fourth Assessment Report (AR4) of the Intergovernmental Panel on Climate Change (IPCC), climate under year 2000 greenhouse gas (GHG) + aerosol forcing was compared with climate under preindustrial conditions. In the tropical Pacific, the warming in the mean sea surface temperatures (SST) was found to have an El Nino-like pattern, while both the equatorial zonal overturning circulation and the meridional overturning circulation weakened under increased GHG forcing. For the El Nino-Southern Oscillation (ENSO), the asymmetry in the SST anomalies between El Nino and La Nina was found to be enhanced under increased GHG, for both the ensemble model data and the observed data (1900-99). Enhanced asymmetry between El Nino and La Nina was also manifested in the anomalies of the zonal wind stress, the equatorial undercurrent, and the meridional overturning circulation in the increased GHG simulations. The enhanced asymmetry in the model SST anomalies was mainly caused by the greatly intensified vertical nonlinear dynamic heating (NDH) anomaly (i.e., product of the vertical velocity anomaly and the negative vertical temperature gradient anomaly) during El Nino (but not during La Nina). Under increased GHG, the enhanced positive NDH anomalies during El Nino, when time averaged over the whole record, would change the SST mean state by an El Nino-like pattern.
C1 [Ye, Zhengqing; Hsieh, William W.] Univ British Columbia, Dept Earth & Ocean Sci, Vancouver, BC V5Z 1M9, Canada.
RP Ye, ZQ (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM zye@pacific.jpl.nasa.gov
RI Hsieh, William/G-8380-2011
OI Hsieh, William/0000-0003-2654-392X
FU Office of Science; U. S. Department of Energy; Natural Sciences and
Engineering Research Council of Canada
FX We thank Dr. Aiming Wu for helpful discussions. We acknowledge the
modeling groups for providing their data for analysis, the Program for
Climate Model Diagnosis and Intercomparison (PCMDI) for collecting and
archiving the model output, and the JSC/CLIVAR Working Group on Coupled
Modelling (WGCM) for organizing the model data analysis activity. The
multimodel data archive is supported by the Office of Science, U. S.
Department of Energy. NOAA-ERSST-V2 data is provided by the
NOAA/OAR/ESRL PSD, Boulder, Colorado, from their Web site at
http://www.cdc.noaa.gov/. This work was supported by the Natural
Sciences and Engineering Research Council of Canada.
NR 39
TC 5
Z9 5
U1 0
U2 3
PU AMER METEOROLOGICAL SOC
PI BOSTON
PA 45 BEACON ST, BOSTON, MA 02108-3693 USA
SN 0894-8755
J9 J CLIMATE
JI J. Clim.
PD NOV 15
PY 2008
VL 21
IS 22
BP 5745
EP 5763
DI 10.1175/2008JCLI1580.1
PG 19
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 375IQ
UT WOS:000261107800001
ER
PT J
AU Dewitte, B
Purca, S
Illig, S
Renault, L
Giese, BS
AF Dewitte, Boris
Purca, Sara
Illig, Serena
Renault, Lionel
Giese, Benjamin S.
TI Low-Frequency Modulation of Intraseasonal Equatorial Kelvin Wave
Activity in the Pacific from SODA: 1958-2001
SO JOURNAL OF CLIMATE
LA English
DT Article
ID MADDEN-JULIAN OSCILLATION; EL-NINO; SEA-LEVEL; LA-NINA; ENSO; OCEAN;
MODEL; VARIABILITY; TOPEX/POSEIDON; RECTIFICATION
AB Intraseasonal equatorial Kelvin wave activity (IEKW) at a low frequency in the Pacific is investigated using the Simple Ocean Data Assimilation (SODA) oceanic reanalyses. A vertical and horizontal mode decomposition of SODA variability allows estimation of the Kelvin wave amplitude according to the most energetic baroclinic modes. A wavenumber-frequency analysis is then performed on the time series to derive indices of modulation of the IEKW at various frequency bands. The results indicate that the IEKW activity undergoes a significant modulation that projects onto baroclinic modes and is not related in a straightforward manner to the low-frequency climate variability in the Pacific. Linear model experiments corroborate that part of the modulation of the IEKW is tightly linked to change in oceanic mean state rather than to the low-frequency change of atmospheric equatorial variability.
C1 [Dewitte, Boris; Illig, Serena; Renault, Lionel] IRD LEGOS, F-31400 Toulouse, France.
[Dewitte, Boris; Purca, Sara] IMARPE, Callao, Peru.
[Illig, Serena] JPL, Pasadena, CA USA.
[Giese, Benjamin S.] Texas A&M Univ, College Stn, TX USA.
RP Dewitte, B (reprint author), IRD LEGOS, 14 Av Edouard Belin, F-31400 Toulouse, France.
EM bxd@imarpe.gob.pe
OI Renault, Lionel/0000-0002-3001-2091; Purca, Sara/0000-0001-8751-1476
NR 49
TC 18
Z9 18
U1 3
U2 6
PU AMER METEOROLOGICAL SOC
PI BOSTON
PA 45 BEACON ST, BOSTON, MA 02108-3693 USA
SN 0894-8755
EI 1520-0442
J9 J CLIMATE
JI J. Clim.
PD NOV 15
PY 2008
VL 21
IS 22
BP 6060
EP 6069
DI 10.1175/2008JCLI2277.1
PG 10
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 375IQ
UT WOS:000261107800021
ER
PT J
AU Olsen, MA
Douglass, AR
Newman, PA
Gille, JC
Nardi, B
Yudin, VA
Kinnison, DE
Khosravi, R
AF Olsen, Mark A.
Douglass, Anne R.
Newman, Paul A.
Gille, John C.
Nardi, Bruno
Yudin, Valery A.
Kinnison, Douglas E.
Khosravi, Rashid
TI HIRDLS observations and simulation of a lower stratospheric intrusion of
tropical air to high latitudes
SO GEOPHYSICAL RESEARCH LETTERS
LA English
DT Article
ID SEASONAL-VARIATION; WATER-VAPOR; TRANSPORT; TROPOSPHERE; TRACER; MODEL
AB On 26 January 2006, the High Resolution Dynamic Limb Sounder (HIRDLS) observed low mixing ratios of ozone and nitric acid in a similar to 2 km layer near 100 hPa extending from the subtropics to 55 degrees N over North America. The subsequent evolution of the layer is simulated with the Global Modeling Initiative model and substantiated with HIRDLS observations. Air with low mixing ratios of ozone is transported poleward to 80 degrees N. Although there is evidence of mixing with extratropical air, much of the tropical intrusion returns to the subtropics. This study demonstrates that HIRDLS and the GMI model resolve thin intrusion events. The observations combined with simulation are a first step towards development of a quantitative understanding of the lower stratospheric ozone budget. Citation: Olsen, M. A., A. R. Douglass, P. A. Newman, J. C. Gille, B. Nardi, V. A. Yudin, D. E. Kinnison, and R. Khosravi (2008), HIRDLS observations and simulation of a lower stratospheric intrusion of tropical air to high latitudes, Geophys. Res. Lett., 35, L21813, doi: 10.1029/2008GL035514.
C1 [Olsen, Mark A.] Univ Maryland, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21201 USA.
[Gille, John C.] Univ Colorado, Ctr Limb Atmospher Sounding, Boulder, CO 80309 USA.
[Gille, John C.; Nardi, Bruno; Yudin, Valery A.; Kinnison, Douglas E.; Khosravi, Rashid] Natl Ctr Atmospher Res, Boulder, CO 80307 USA.
[Douglass, Anne R.; Newman, Paul A.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
RP Olsen, MA (reprint author), Univ Maryland, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21201 USA.
EM mark.olsen@nasa.gov
RI Newman, Paul/D-6208-2012; Douglass, Anne/D-4655-2012
OI Newman, Paul/0000-0003-1139-2508;
FU NASA's EOS IDS; ACMAP
FX This work was supported by NASA's EOS IDS and ACMAP programs.
NR 20
TC 16
Z9 16
U1 1
U2 3
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0094-8276
J9 GEOPHYS RES LETT
JI Geophys. Res. Lett.
PD NOV 14
PY 2008
VL 35
IS 21
AR L21813
DI 10.1029/2008GL035514
PG 6
WC Geosciences, Multidisciplinary
SC Geology
GA 373RX
UT WOS:000260991300002
ER
PT J
AU Campbell, JE
Carmichael, GR
Chai, T
Mena-Carrasco, M
Tang, Y
Blake, DR
Blake, NJ
Vay, SA
Collatz, GJ
Baker, I
Berry, JA
Montzka, SA
Sweeney, C
Schnoor, JL
Stanier, CO
AF Campbell, J. E.
Carmichael, G. R.
Chai, T.
Mena-Carrasco, M.
Tang, Y.
Blake, D. R.
Blake, N. J.
Vay, S. A.
Collatz, G. J.
Baker, I.
Berry, J. A.
Montzka, S. A.
Sweeney, C.
Schnoor, J. L.
Stanier, C. O.
TI Photosynthetic Control of Atmospheric Carbonyl Sulfide During the
Growing Season
SO SCIENCE
LA English
DT Article
ID GROSS PRIMARY PRODUCTION; ECOSYSTEM RESPIRATION; CO2; MODEL; EXCHANGE;
FLUXES; STRATOSPHERE; CONSUMPTION; VEGETATION; FEEDBACKS
AB Climate models incorporate photosynthesis- climate feedbacks, yet we lack robust tools for large- scale assessments of these processes. Recent work suggests that carbonyl sulfide ( COS), a trace gas consumed by plants, could provide a valuable constraint on photosynthesis. Here we analyze airborne observations of COS and carbon dioxide concentrations during the growing season over North America with a three- dimensional atmospheric transport model. We successfully modeled the persistent vertical drawdown of atmospheric COS using the quantitative relation between COS and photosynthesis that has been measured in plant chamber experiments. Furthermore, this drawdown is driven by plant uptake rather than other continental and oceanic fluxes in the model. These results provide quantitative evidence that COS gradients in the continental growing season may have broad use as a measurement- based photosynthesis tracer.
C1 [Campbell, J. E.; Schnoor, J. L.] Univ Iowa, Dept Civil & Environm Engn, Iowa City, IA 52242 USA.
[Carmichael, G. R.; Tang, Y.; Stanier, C. O.] Univ Iowa, Ctr Global & Reg Environm Res, Iowa City, IA 52242 USA.
[Chai, T.] Sci & Technol Corp, Hampton, VA 23666 USA.
[Mena-Carrasco, M.] Univ Andres Bello, Dept Environm Engn, Santiago, Chile.
[Mena-Carrasco, M.] MIT, Molina Ctr Energy & Environm, Cambridge, MA 02139 USA.
[Blake, D. R.; Blake, N. J.] Univ Calif Irvine, Dept Chem, Irvine, CA 92697 USA.
[Vay, S. A.] NASA, Langley Res Ctr, Hampton, VA 23681 USA.
[Collatz, G. J.] NASA, Goddard Space Flight Ctr, Biospher Sci Branch, Greenbelt, MD 20771 USA.
[Baker, I.] Colorado State Univ, Dept Atmospher Sci, Ft Collins, CO 80523 USA.
[Berry, J. A.] Carnegie Inst Sci, Dept Global Ecol, Stanford, CA 94305 USA.
[Montzka, S. A.] NOAA, Earth Syst Res Lab, Global Monitoring Div, Boulder, CO 80305 USA.
[Sweeney, C.] Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80304 USA.
RP Campbell, JE (reprint author), Univ Calif Merced, Coll Engn, Merced, CA 95344 USA.
EM ecampbell3@ucmerced.edu
RI Campbell, Elliott/B-8025-2008; Chai, Tianfeng/E-5577-2010; collatz,
george/D-5381-2012; Mena-Carrasco, Marcelo/B-8483-2012; Stanier,
Charles/D-4307-2016; Tang, Youhua/D-5205-2016; Mena-Carrasco,
Marcelo/L-9730-2016;
OI Chai, Tianfeng/0000-0003-3520-2641; Stanier,
Charles/0000-0001-9924-0853; Tang, Youhua/0000-0001-7089-7915; Berry,
Joseph A/0000-0002-5849-6438; Montzka, Stephen/0000-0002-9396-0400
FU NASA Earth System Science Graduate Fellowship; Center for Global and
Regional Environmental Research; NOAA Office of Oceanic and Atmospheric
Research contribution to the North American Carbon Program; NASA INTEX;
NSF Information Technology Research
FX We thank J. Kettle for COS flux data and C. Tebaldi, J. Dungan, T.
Campbell, and D. Campbell for critical comments on the manuscript. This
research was supported by a NASA Earth System Science Graduate
Fellowship, Center for Global and Regional Environmental Research, NOAA
Office of Oceanic and Atmospheric Research contribution to the North
American Carbon Program, NASA INTEX, and NSF Information Technology
Research grants. NOAA observations of COS and CO2 were made
possible by the assistance of P. Tans, C. Sweeney, L. Miller, T. Conway,
P. Lang, C. Siso, and B. Hall.
NR 30
TC 69
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U1 2
U2 44
PU AMER ASSOC ADVANCEMENT SCIENCE
PI WASHINGTON
PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA
SN 0036-8075
J9 SCIENCE
JI Science
PD NOV 14
PY 2008
VL 322
IS 5904
BP 1085
EP 1088
DI 10.1126/science.1164015
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA 371YD
UT WOS:000260867700033
PM 19008442
ER
PT J
AU Stallard, T
Miller, S
Lystrup, M
Achilleos, N
Bunce, EJ
Arridge, CS
Dougherty, MK
Cowley, SWH
Badman, SV
Talboys, DL
Brown, RH
Baines, KH
Buratti, BJ
Clark, RN
Sotin, C
Nicholson, PD
Drossart, P
AF Stallard, Tom
Miller, Steve
Lystrup, Makenzie
Achilleos, Nicholas
Bunce, Emma J.
Arridge, Christopher S.
Dougherty, Michele K.
Cowley, Stan W. H.
Badman, Sarah V.
Talboys, Dean L.
Brown, Robert H.
Baines, Kevin H.
Buratti, Bonnie J.
Clark, Roger N.
Sotin, Christophe
Nicholson, Phil D.
Drossart, Pierre
TI Complex structure within Saturn's infrared aurora
SO NATURE
LA English
DT Article
ID JOVIAN IONOSPHERE; EMISSION; TEMPERATURE; DYNAMICS
AB The majority of planetary aurorae are produced by electrical currents flowing between the ionosphere and the magnetosphere which accelerate energetic charged particles that hit the upper atmosphere. At Saturn, these processes collisionally excite hydrogen, causing ultraviolet emission(1-8), and ionize the hydrogen, leading to H-3(+) infrared emission(9-15). Although the morphology of these aurorae is affected by changes in the solar wind(6,11), the source of the currents which produce them is a matter of debate(16,17). Recent models predict only weak emission away from the main auroral oval(18). Here we report images that show emission both poleward and equatorward of the main oval (separated by a region of low emission). The extensive polar emission is highly variable with time, and disappears when the main oval has a spiral morphology; this suggests that although the polar emission may be associated with minor increases in the dynamic pressure from the solar wind, it is not directly linked to strong magnetospheric compressions. This aurora appears to be unique to Saturn and cannot be explained using our current understanding of Saturn's magnetosphere. The equatorward arc of emission exists only on the nightside of the planet, and arises from internal magnetospheric processes that are currently unknown.
C1 [Stallard, Tom; Bunce, Emma J.; Cowley, Stan W. H.; Badman, Sarah V.; Talboys, Dean L.] Univ Leicester, Dept Phys & Astron, Leicester LE1 7RH, Leics, England.
[Miller, Steve; Lystrup, Makenzie; Achilleos, Nicholas] UCL, Atmospher Phys Lab, Dept Phys & Astron, London WC1E 6BT, England.
[Arridge, Christopher S.] Univ Coll London, Mullard Space Sci Lab, Dept Space & Climate Phys, Dorking RH5 6NT, Surrey, England.
[Dougherty, Michele K.] Univ London Imperial Coll Sci Technol & Med, Dept Phys, Space & Atmospher Phys Grp, London SW7 2AZ, England.
[Brown, Robert H.] Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA.
[Brown, Robert H.] Univ Arizona, Steward Observ, Tucson, AZ 85721 USA.
[Baines, Kevin H.; Buratti, Bonnie J.; Sotin, Christophe] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[Clark, Roger N.] US Geol Survey, Lakewood, CO 80225 USA.
[Nicholson, Phil D.] Cornell Univ, Dept Astron, Ithaca, NY 14853 USA.
[Drossart, Pierre] Observ Paris, F-92195 Meudon, France.
RP Stallard, T (reprint author), Univ Leicester, Dept Phys & Astron, Leicester LE1 7RH, Leics, England.
EM tss@ion.le.ac.uk
RI Arridge, Christopher/A-2894-2009; Achilleos, Nicholas/C-1647-2008;
Bunce, Emma/I-9067-2016;
OI Stallard, Tom/0000-0003-3990-670X; Arridge,
Christopher/0000-0002-0431-6526; Bunce, Emma/0000-0002-9456-0345;
Achilleos, Nicholas/0000-0002-5886-3509
FU Research Councils UK Fellowship; UK Science and Technology Facilities
Council; European Union's Sixth Framework Programme
FX This work was supported by a Research Councils UK Fellowship (T.S.) and
by the UK Science and Technology Facilities Council (N.A., S.V.B.,
D.L.T., C.S.A., E.J.B., M.K.D.). The European authors are part of the
Europlanet European Planetology Network, supported by the European
Union's Sixth Framework Programme.
NR 26
TC 28
Z9 28
U1 0
U2 8
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
J9 NATURE
JI Nature
PD NOV 13
PY 2008
VL 456
IS 7219
BP 214
EP 217
DI 10.1038/nature07440
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA 374JJ
UT WOS:000261039300034
PM 19005549
ER
PT J
AU Kwok, R
Hunke, EC
Maslowski, W
Menemenlis, D
Zhang, J
AF Kwok, R.
Hunke, E. C.
Maslowski, W.
Menemenlis, D.
Zhang, J.
TI Variability of sea ice simulations assessed with RGPS kinematics
SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
LA English
DT Article
ID THICKNESS DISTRIBUTION; FLUX MEASUREMENTS; ARCTIC-OCEAN; PACK ICE;
MODEL; DEFORMATION; MOTION; ASSIMILATION; DYNAMICS; SYSTEM
AB Sea ice drift and deformation from coupled ice-ocean models are compared with high-resolution ice motion from the RADARSAT Geophysical Processor System (RGPS). In contrast to buoy drift, the density and extent of the RGPS coverage allows a more extensive assessment and understanding of model simulations at spatial scales from similar to 10 km to near basin scales and from days to seasonal timescales. This work illustrates the strengths of the RGPS data set as a basis for examining model ice drift and its gradients. As it is not our intent to assess relative performance, we have selected four models with a range of attributes and grid resolution. Model fields are examined in terms of ice drift, export, deformation, deformation-related ice production, and spatial deformation patterns. Even though the models are capable of reproducing large-scale drift patterns, variability among model behavior is high. When compared to the RGPS kinematics, the characteristics shared by the models are (1) ice drift along coastal Alaska and Siberia is slower, (2) the skill in explaining the time series of regional divergence of the ice cover is poor, and (3) the deformation-related volume production is consistently lower. Attribution of some of these features to specific causes is beyond our current scope because of the complex interplay between model processes, parameters, and forcing. The present work suggests that high-resolution ice drift observations, like those from the RGPS, would be essential for future model developments, improvements, intercomparisons, and especially for evaluation of the small-scale behavior of models with finer grid spacing.
C1 [Kwok, R.; Menemenlis, D.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[Hunke, E. C.] Los Alamos Natl Lab, Climate Ocean & Sea Ice Modeling Program, Los Alamos, NM USA.
[Maslowski, W.] USN, Postgrad Sch, Grad Sch Engn & Appl Sci, Dept Oceanog, Monterey, CA USA.
[Zhang, J.] Univ Washington, Coll Ocean & Fishery Sci, Appl Phys Lab, Polar Sci Ctr, Seattle, WA 98105 USA.
RP Kwok, R (reprint author), CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
EM ron.kwok@jpl.nasa.gov
RI Kwok, Ron/A-9762-2008
OI Kwok, Ron/0000-0003-4051-5896
FU Climate Change Prediction Program of the Department of Energy's Office
of Biological and Environmental Research; NSF [ARC0629326, ARC0629312,
ARC0611967]; NASA [NNG04GB03G, NNG04GH52G]; National Aeronautics and
Space Administration; Department of Energy; National Science Foundation
FX We wish to thank S. S. Pang for her software support during the
preparation of this paper. The RGPS data are provided by the Jet
Propulsion Laboratory and the Alaska Satellite Facility through a
project sponsored by the NASA Earth Science REASoN Program (data are
available at http://www-radar.jpl.nasa.gov/rgps/radarsat.html). E. Hunke
is supported by the Climate Change Prediction Program of the Department
of Energy's Office of Biological and Environmental Research. J. Zhang is
supported by NSF (grants ARC0629326, ARC0629312, and ARC0611967) and
NASA (grants NNG04GB03G and NNG04GH52G). The NPS contribution has been
funded through grants from the National Aeronautics and Space
Administration, Department of Energy, and National Science Foundation.
Computer resources for the NPS work are provided by the Arctic Region
Supercomputing Center under the Department of Defense High Performance
Computer Modernization Program. The ECCO2 products are provided by the
consortium for Estimating the Circulation and Climate of the Ocean,
Phase II (ECCO2 data are available at http://ecco2.org/). The ECCO2
project is sponsored by the NASA Modeling Analysis and Prediction (MAP)
program. R. Kwok and D. Menemenlis carried out this work at the Jet
Propulsion Laboratory, California Institute of Technology under contract
with the National Aeronautics and Space Administration.
NR 62
TC 31
Z9 32
U1 0
U2 2
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0148-0227
J9 J GEOPHYS RES-OCEANS
JI J. Geophys. Res.-Oceans
PD NOV 12
PY 2008
VL 113
IS C11
AR C11012
DI 10.1029/2008JC004783
PG 20
WC Oceanography
SC Oceanography
GA 373TH
UT WOS:000260995700001
ER
PT J
AU Segura, TL
Toon, OB
Colaprete, A
AF Segura, Teresa L.
Toon, O. Brian
Colaprete, Anthony
TI Modeling the environmental effects of moderate-sized impacts on Mars
SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS
LA English
DT Article
ID CARBON-DIOXIDE CLOUDS; ASTEROID IMPACTS; VALLEY NETWORKS; EARLY EARTH;
GROUND ICE; EROSION; CLIMATE; CHANNELS; DEPOSITS; SYSTEMS
AB We have modeled the effects of moderate-sized (30-100 km diameter) impacts on Mars using a one-dimensional radiative-convective model. The model computes the evolution of temperature following an impact and includes a subsurface model to compute the evolution of the ground temperature; a hydrological cycle to follow the evaporation, condensation, and precipitation of injected and surface-evaporated water; a radiative transfer code to compute greenhouse warming by CO(2), water vapor, and water clouds; and an atmospheric thermodynamics module to compute the latent heating due to cloud formation/dissipation. We have found that parts of the Martian regolith may be kept above freezing for 95 days to decades by the modeled events. However, if we include the radiative effects of water clouds, a sustained greenhouse climate is computed for impactors 50 km in size that could be centuries long. The amount of water precipitated out of the atmosphere from vaporization of impactor, target, and polar caps yields global rainfall totals ranging from 40 to 18 m depending on the size of the impactor and assumed background CO(2) atmosphere. We also estimate the surface erosion following precipitation events and find that the total erosion done by all impactors in time is the same order of magnitude as the total erosion estimated to have occurred on early Mars.
C1 [Segura, Teresa L.] Northrop Grumman Space Technol, Civil Syst Div, Redondo Beach, CA 90278 USA.
[Toon, O. Brian] Univ Colorado, Dept Atmospher & Ocean Sci, Boulder, CO 80309 USA.
[Colaprete, Anthony] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
RP Segura, TL (reprint author), Northrop Grumman Space Technol, Civil Syst Div, E1 4037,1 Space Pk Dr,Redondo Beach, Redondo Beach, CA 90278 USA.
EM teresa.segura@ngc.com; btoon@lasp.colorado.edu;
tonyc@freeze.arc.nasa.gobv
FU NASA [NNX08AG93G]; Northrop Grumman
FX The authors would like to thank the NASA Graduate Student Researchers
Program, NASA Grant NNX08AG93G, and Northrop Grumman discretionary
resources for the funding for this research. The authors would like to
thank Kevin Zahnle for valuable input and our reviewers for their
insightful questions, comments, and suggestions.
NR 51
TC 49
Z9 49
U1 0
U2 3
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0148-0227
J9 J GEOPHYS RES-PLANET
JI J. Geophys. Res.-Planets
PD NOV 12
PY 2008
VL 113
IS E11
AR E11007
DI 10.1029/2008JE003147
PG 15
WC Geochemistry & Geophysics
SC Geochemistry & Geophysics
GA 373TM
UT WOS:000260996400002
ER
PT J
AU Smith, HT
Shappirio, M
Johnson, RE
Reisenfeld, D
Sittler, EC
Crary, FJ
McComas, DJ
Young, DT
AF Smith, H. T.
Shappirio, M.
Johnson, R. E.
Reisenfeld, D.
Sittler, E. C.
Crary, F. J.
McComas, D. J.
Young, D. T.
TI Enceladus: A potential source of ammonia products and molecular nitrogen
for Saturn's magnetosphere
SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
LA English
DT Article
ID NEUTRAL MASS-SPECTROMETER; CASSINI ION; SATELLITES; EVOLUTION; PLASMA
AB The detection of nitrogen species in Saturn's magnetosphere could, in principle, provide clues to the origin and evolution of its satellites and tenuous rings. Smith et al. (2005) first identified low-energy N+ using the Cassini Plasma Spectrometer (CAPS). N+ was predominantly seen in the Saturn's inner magnetosphere (= 0.4. The error distributions have not shown any significant tendency with other aerosol radiative properties as well as size and shape particles.
C1 [Garcia, O. E.; Diaz, A. M.; Exposito, F. J.; Diaz, J. P.] Univ La Laguna, Grp Observac Tierra & Atmosfera, Dept Fis FEES, E-38320 Tenerife, Spain.
[Dubovik, O.; Dubuisson, P.; Derimian, Y.] Univ Sci & Tech Lille Flandres Artois, Opt Atmospher Lab, F-59655 Villeneuve Dascq, France.
[Dutton, E. G.] NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80305 USA.
[Eck, T. F.; Sinyuk, A.] NASA, Goddard Space Flight Ctr, Terr Phys Lab, Greenbelt, MD 20771 USA.
[Holben, B. N.] NASA, Goddard Space Flight Ctr, Biol Sci Branch, Greenbelt, MD 20771 USA.
[Roger, J-C] Univ Clermont Ferrand, Lab Meteorol Phys, Clermont Ferrand, France.
[Eck, T. F.] Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21228 USA.
[Sinyuk, A.; Schafer, J. S.] Sci Syst & Applicat Inc, Lanham, MD USA.
RP Garcia, OE (reprint author), Univ La Laguna, Grp Observac Tierra & Atmosfera, Dept Fis FEES, Avda Astrofis Francisco Sanchez S-N, E-38320 Tenerife, Spain.
EM ogarcia@ull.es
RI Dubovik, Oleg/A-8235-2009; Schafer, Joel/A-3978-2010; ECK,
THOMAS/D-7407-2012; Garcia, Omaira/M-2896-2014;
OI Dubovik, Oleg/0000-0003-3482-6460; Exposito, Francisco
Javier/0000-0002-6946-6090
FU Ministry of Education and Science (MEC, Spain) [CGL2004-05984-C07-05,
CGL2005-03428-C04-02, CGL2007-66477-C02-02/CLI, and PI042005/033]
FX We acknowledge the Ministry of Education and Science (MEC, Spain) for
the next supports: projects CGL2004-05984-C07-05, CGL2005-03428-C04-02,
and CGL2007-66477-C02-02/CLI, and PI042005/033. We gratefully
acknowledge the data provided by BSRN, SolRad-Net, MLO, and AERONET
networks. Finally, we wish to express our appreciation to the operators
of stations for their help on running the instruments.
NR 60
TC 38
Z9 38
U1 3
U2 9
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 2169-897X
EI 2169-8996
J9 J GEOPHYS RES-ATMOS
JI J. Geophys. Res.-Atmos.
PD NOV 11
PY 2008
VL 113
IS D21
AR D21207
DI 10.1029/2008JD010211
PG 16
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 373SF
UT WOS:000260992100003
ER
PT J
AU Holmes, WA
Bock, JJ
Crill, BP
Koch, TC
Jones, WC
Lange, AE
Paine, CG
AF Holmes, Warren A.
Bock, James J.
Crill, Brendan P.
Koch, Timothy C.
Jones, William C.
Lange, Andrew E.
Paine, Christopher G.
TI Initial test results on bolometers for the Planck high frequency
instrument
SO APPLIED OPTICS
LA English
DT Article
ID HOPPING CONDUCTION; DOPED GERMANIUM; NOISE; NONLINEARITIES;
OPTIMIZATION; PERFORMANCE; BOOMERANG; DETECTORS; SURVEYOR; RECEIVER
AB We summarize the fabrication, flight qualification, and dark performance of bolometers completed at the Jet Propulsion Laboratory for the High Frequency Instrument (HFI) of the joint ESA/NASA Herschel/Planck mission to be launched in 2009. The HFI is a multicolor focal plane which consists of 52 bolometers operated at 100 mK. Each bolometer is mounted to a feedhorn-filter assembly which defines one of six frequency bands centered between 100-857 GHz. Four detectors in each of five bands from 143-857 GHz are coupled to both linear polarizations and thus measure the total intensity. In addition, eight detectors in each of four bands (100, 143, 217, and 353 GHz) couple only to a single linear polarization and thus provide measurements of the Stokes parameters, Q and U, as well as the total intensity. The measured noise equivalent power (NEP) of all detectors is at or below the background limit for the telescope and time constants are a few ms, short enough to resolve point sources as the 5 to 9 are min beams move across the sky at 1 rpm. (c) 2008 Optical Society of America
C1 [Holmes, Warren A.; Bock, James J.; Crill, Brendan P.; Koch, Timothy C.; Jones, William C.; Lange, Andrew E.; Paine, Christopher G.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[Crill, Brendan P.] CALTECH, Ctr Infrared Proc & Anal, Pasadena, CA 91125 USA.
[Jones, William C.] Princeton Univ, Dept Phys, Princeton, NJ 08544 USA.
RP Holmes, WA (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM Warren.A.Holmes@jpl.nasa.gov
NR 32
TC 28
Z9 28
U1 0
U2 4
PU OPTICAL SOC AMER
PI WASHINGTON
PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA
SN 1559-128X
EI 2155-3165
J9 APPL OPTICS
JI Appl. Optics
PD NOV 10
PY 2008
VL 47
IS 32
BP 5996
EP 6008
DI 10.1364/AO.47.005996
PG 13
WC Optics
SC Optics
GA 380DZ
UT WOS:000261447700006
PM 19002223
ER
PT J
AU Elsner, RF
Heinke, CO
Cohn, HN
Lugger, PM
Maxwell, JE
Stairs, IH
Ransom, SM
Hessels, JWT
Becker, W
Huang, RHH
Edmonds, PD
Grindlay, JE
Bogdanov, S
Ghosh, K
Weisskopf, MC
AF Elsner, Ronald F.
Heinke, Craig O.
Cohn, Haldan N.
Lugger, Phyllis M.
Maxwell, J. Edward
Stairs, Ingrid H.
Ransom, Scott M.
Hessels, Jason W. T.
Becker, Werner
Huang, Regina H. H.
Edmonds, Peter D.
Grindlay, Jonathan E.
Bogdanov, Slavko
Ghosh, Kajal
Weisskopf, Martin C.
TI CHANDRA X-RAY OBSERVATORY OBSERVATIONS OF THE GLOBULAR CLUSTER M71
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE globular clusters: individual (M71 NGC 6838); pulsars: individual (PSR
J1953+1846A, M71A); X-rays: binaries; X-rays: stars
ID HUBBLE-SPACE-TELESCOPE; GLOBULAR-CLUSTER-47 TUCANAE; MILLISECOND PULSAR;
BINARIES; CATALOG; CORE; NGC-6397; ARECIBO; PLASMAS; M4
AB We observe the nearby, low-density globular cluster M71 (NGC 6838) with the Chandra X-Ray Observatory to study its faint X-ray populations. Five X-ray sources are found inside the cluster core radius, including the known eclipsing binary millisecond pulsar (MSP) PSR J1953+1846A. The X-ray light curve of the source coincident with this MSP shows marginal evidence for periodicity at the binary period of 4.2 hr. Its hard X-ray spectrum and luminosity resemble those of other eclipsing binary MSPs in 47 Tuc, suggesting a similar shock origin of the X-ray emission. A further 24 X-ray sources are found within the half-mass radius, reaching to a limiting luminosity of 1.5 x 10(30) ergs s (1) (0.3-8 keV). From a radial distribution analysis, we find that 18 +/- 6 of these 29 sources are associated with M71, somewhat more than predicted, and that 11 +/- 6 are background sources, both Galactic and extragalactic. M71 appears to have more X-ray sources in the range L-X - 10(30) -10(31) ergs s(-1) than expected by extrapolating from other studied clusters using either mass or collision frequency. We explore the spectra and variability of these sources and describe the results of ground-based optical counterpart searches.
C1 [Elsner, Ronald F.; Ghosh, Kajal; Weisskopf, Martin C.] NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA.
[Heinke, Craig O.] Univ Alberta, Dept Phys, Edmonton, AB T6G 267, Canada.
[Cohn, Haldan N.; Lugger, Phyllis M.; Maxwell, J. Edward] Indiana Univ, Dept Astron, Bloomington, IN 47405 USA.
[Stairs, Ingrid H.] Univ British Columbia, Dept Phys & Astron, Vancouver, BC V6T 1Z1, Canada.
[Ransom, Scott M.] Natl Radio Astron Observ, Charlottesville, VA 22903 USA.
[Hessels, Jason W. T.] Univ Amsterdam, Astron Inst Anton Pannekoek, NL-1098 SJ Amsterdam, Netherlands.
[Becker, Werner; Huang, Regina H. H.] Max Planck Inst Extraterr Phys, D-85741 Garching, Germany.
[Edmonds, Peter D.; Grindlay, Jonathan E.; Bogdanov, Slavko] Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA.
RP Elsner, RF (reprint author), NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA.
EM ron.elsner@nasa.gov
OI Bogdanov, Slavko/0000-0002-9870-2742; Heinke, Craig/0000-0003-3944-6109
FU Northwestern University; University of Virginia; NASA's Marshall Space
Flight Center (MSFC); NSERC Discovery
FX This research has made use of data obtained from the High Energy
Astrophysics Science Archive Center (HEASARC), provided by NASA's
Goddard Space Flight Center. C. O. H. acknowledges support from a
Lindheimer Postdoctoral Fellowship at Northwestern University and from
Chandra Guest Observer grants at the University of Virginia. Those of us
at NASA's Marshall Space Flight Center (MSFC) acknowledge support from
the Chandra Program, as well as from the Chandra Guest Observer
Programadministered by the Chandra X-ray Center. J. W. T. H. is funded
by an NSERC postdoctoral fellowship and CSA supplement. Pulsar research
at UBC is supported by an NSERC Discovery Grant. We also thank Allyn
Tennant for discussions of source finding and many aspects of Chandra
data analysis, as well as for sharing useful scripts. Finally, we thank
the referee for several helpful comments and questions.
NR 50
TC 15
Z9 15
U1 0
U2 3
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD NOV 10
PY 2008
VL 687
IS 2
BP 1019
EP 1034
DI 10.1086/591899
PG 16
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 367QG
UT WOS:000260566700021
ER
PT J
AU Williams, BJ
Borkowski, KJ
Reynolds, SP
Raymond, JC
Long, KS
Morse, J
Blair, WP
Ghavamian, P
Sankrit, R
Hendrick, SP
Smith, RC
Points, S
Winkler, PF
AF Williams, Brian J.
Borkowski, Kazimierz J.
Reynolds, Stephen P.
Raymond, John C.
Long, Knox S.
Morse, Jon
Blair, William P.
Ghavamian, Parviz
Sankrit, Ravi
Hendrick, Sean P.
Smith, R. Chris
Points, Sean
Winkler, P. Frank
TI EJECTA, DUST, AND SYNCHROTRON RADIATION IN SNR B0540-69.3: A MORE
CRAB-LIKE REMNANT THAN THE CRAB
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE dust, extinction; Magellanic Clouds; pulsars: individual (SNR
0540-69.3); supernova remnants
ID LARGE-MAGELLANIC-CLOUD; RICH SUPERNOVA-REMNANTS; SPACE-TELESCOPE
OBSERVATIONS; NOVA REMNANTS; MILLISECOND PULSAR; PLANETARY SYSTEM;
MAGNETIC-FIELD; MASSIVE STARS; PSR B0540-69; CASSIOPEIA-A
AB We present near- and mid-infrared observations of the pulsar-wind nebula (PWN) SNR B0540-69.3 and its associated supernova remnant made with the Spitzer Space Telescope. We report detections of the PWN with all four IRAC bands, the 24 mu m band of MIPS, and the Infrared Spectrograph (IRS). We find no evidence of IR emission from the X-ray/radio shell surrounding the PWN resulting from the forward shock of the supernova blast wave. The flux of the PWN itself is dominated by synchrotron emission at shorter (IRAC) wavelengths, with a warm dust component longward of 20 mu m. We show that this dust continuum can be explained by a small amount [similar to(1-3) x 10(-3) M-circle dot] of dust at a temperature of similar to 50-65 K, heated by the shock wave generated by the PWN being driven into the inner edge of the ejecta. This is evidently dust synthesized in the supernova. We also report the detection of several lines in the spectrum of the PWN and present kinematic information about the PWN as determined from these lines. Kinematics are consistent with previous optical studies of this object. Line strengths are also broadly consistent with what one expects from optical line strengths. We find that lines arise from slow (similar to 20 km s(-1)) shocks driven into oxygen-rich clumps in the shell swept up by an iron-nickel bubble, which have a density contrast of similar to 100-200 relative to the bulk of the ejecta, and that faster shocks (similar to 250 km s(-1)) in the hydrogen envelope are required to heat dust grains to observed temperatures. We infer from estimates of heavy-element ejecta abundances that the progenitor star was likely in the range of 20-25 M-circle dot.
C1 [Williams, Brian J.; Borkowski, Kazimierz J.; Reynolds, Stephen P.] N Carolina State Univ, Dept Phys, Raleigh, NC 27695 USA.
[Raymond, John C.] Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA.
[Long, Knox S.] Space Telescope Sci Inst, Baltimore, MD 21218 USA.
[Morse, Jon] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
[Blair, William P.; Ghavamian, Parviz] Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA.
[Sankrit, Ravi] Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA.
[Hendrick, Sean P.] Millersville Univ Pennsylvania, Dept Phys, Millersville, PA 17551 USA.
[Smith, R. Chris; Points, Sean] Cerro Tololo Interamer Observ, La Serena, Chile.
[Winkler, P. Frank] Middlebury Coll, Dept Phys, Middlebury, VT 05753 USA.
RP Williams, BJ (reprint author), N Carolina State Univ, Dept Phys, Raleigh, NC 27695 USA.
EM bjwilli2@ncsu.edu
FU Spitzer Guest Observer [RSA 170640]
FX We thank the referee for useful comments, and gratefully acknowledge
support through Spitzer Guest Observer grant RSA 170640.
NR 65
TC 30
Z9 30
U1 0
U2 4
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD NOV 10
PY 2008
VL 687
IS 2
BP 1054
EP 1069
DI 10.1086/592139
PG 16
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 367QG
UT WOS:000260566700024
ER
PT J
AU Sidoli, L
Romano, P
Mangano, V
Pellizzoni, A
Kennea, JA
Cusumano, G
Vercellone, S
Paizis, A
Burrows, DN
Gehrels, N
AF Sidoli, L.
Romano, P.
Mangano, V.
Pellizzoni, A.
Kennea, J. A.
Cusumano, G.
Vercellone, S.
Paizis, A.
Burrows, D. N.
Gehrels, N.
TI MONITORING SUPERGIANT FAST X-RAY TRANSIENTS WITH SWIFT. I. BEHAVIOR
OUTSIDE OUTBURSTS
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE X-rays: individual (AX J1841.0-0536/IGR J18410-0535, IGR J16479-4514,
IGR J17544-2619, XTE J1739-302)
ID CLUMPY STELLAR WINDS; XTE J1739-302; IGR J11215-5952; NEUTRON-STAR;
CATALOG; REGION; ASCA
AB Supergiant fast X-ray transients (SFXTs) are a new class of high-mass X-ray binaries (HMXBs) discovered thanks to the monitoring of the Galactic plane performed with the INTEGRAL satellite in the last 5 years. These sources display short outbursts (significantly shorter than typical Be/X-ray binaries) with a peak luminosity of a few 1036 erg s(-1). The quiescent level, measured only in a few sources, is around 1032 erg s(-1). The X- ray spectral properties are reminiscent of those of accreting pulsars; thus, it is likely that all the members of the new class are indeed HMXBs hosting a neutron star, although only two SFXTs have a measured pulse period, IGR J11215-5952 (similar to 187 s) and IGR J18410-0535 (similar to 4.7 s). Several competing mechanisms have been proposed to explain the shortness of these outbursts, mostly involving the structure of the wind from the supergiant companion. To characterize the properties of these sources on timescales of months (e. g., the quiescent level and the outburst recurrence), we are performing a monitoring campaign with Swift of four SFXTs (IGR J16479-4514, XTE J1739-302, IGR J17544-2619, and AX J1841.0-0536/IGR J18410-0535). We report on the first 4 months of Swift observations, which started on 2007 October 26. We detect low-level X- ray activity in all four SFXTs, which demonstrates that these transient sources accrete matter even outside their outbursts. This fainter X- ray activity is composed of many flares with a large flux variability, on timescales of thousands of seconds. The light-curve variability is also evident on larger timescales of days, weeks, and months, with a dynamic range of more than 1 order of magnitude in all four SFXTs. The X- ray spectra are typically hard, with an average 2-10 keV luminosity during this monitoring of about 1033-1034 erg s(-1). We detected pulsations from the pulsar AX J1841.0-0536/IGR J18410-0535, with a period of 4: 7008 +/- 0: 0004 s. This monitoring demonstrates that these transients spend most of the time accreting matter, although at a much lower level (similar to 100-1000 times lower) than during the bright outbursts, and that the "true quiescence,'' characterized by a soft spectrum and a luminosity of a few 1032 erg s(-1), observed in the past in only a couple of members of this class, is probably a very rare state.
C1 [Sidoli, L.; Pellizzoni, A.; Vercellone, S.; Paizis, A.] INAF, Ist Astrofis Spaziale & Fis Cosm, I-20133 Milan, Italy.
[Romano, P.; Mangano, V.; Cusumano, G.] INAF, Ist Astrofis Spaziale & Fis Cosm, I-90146 Palermo, Italy.
[Kennea, J. A.; Burrows, D. N.] Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA.
[Gehrels, N.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
RP Sidoli, L (reprint author), INAF, Ist Astrofis Spaziale & Fis Cosm, Via E Bassini 15, I-20133 Milan, Italy.
RI Gehrels, Neil/D-2971-2012;
OI Vercellone, Stefano/0000-0003-1163-1396; Sidoli,
Lara/0000-0001-9705-2883; Paizis, Adamantia/0000-0001-5067-0377;
Cusumano, Giancarlo/0000-0002-8151-1990
FU MIUR [2005-025417]; ASI/INAF [I/023/05/0, I/008/07/0, I/088/06/0]; Swift
NASA [NAS5-00136]
FX We thank the Swift team for making these observations possible, in
particular the duty scientists and science planners. This work was
supported by MIUR grant 2005-025417, contracts ASI/INAF I/023/05/0,
I/008/07/0, and I/088/06/0, and Swift NASA contract NAS5-00136. P. R.
thanks INAF-IASFMi, where part of the work was carried out, for their
kind hospitality. We thank the anonymous referee for a swift and very
constructive report.
NR 25
TC 56
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U1 0
U2 2
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD NOV 10
PY 2008
VL 687
IS 2
BP 1230
EP 1235
DI 10.1086/590077
PG 6
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 367QG
UT WOS:000260566700036
ER
PT J
AU Sekanina, Z
Chodas, PW
AF Sekanina, Zdenek
Chodas, Paul W.
TI A NEW ORBIT DETERMINATION FOR BRIGHT SUNGRAZING COMET OF 1843
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE astrometry; celestial mechanics; comets: general; comets: individual
(C/1843 D1, C/1880 C1, C/1882 R1, C/1963 R1, C/1965 S1, X/1106 C1);
methods: data analysis
ID KREUTZ SYSTEM; FRAGMENTATION; HIERARCHY; EVOLUTION; ORIGIN; BIRTH
AB Given the critical role of the bright sungrazer C/1843 D1, also called the Great March Comet of 1843, in hypotheses of the origin and evolution of the Kreutz system, a new orbital investigation of this comet was desirable. Closely inspecting Kreutz's classical work, we conclude that his result of 512 yr for the orbital period, which has been endlessly quoted in the literature and employed in studies of the sungrazer system's evolution, is not realistic. We derive improved sets of orbital elements based on the best astrometric observations available from 1843, using new comparison star positions from the Hipparcos and Tycho Catalogues. We find that the 1843 osculating value of the orbital period was most probably between 600 and 800 yr and that the observations are consistent with a forced value of 742 yr, in which case comet C/1843 D1 could be a major (and possibly the most massive) fragment of X/1106 C1, the celebrated sungrazer of 1106.
C1 [Sekanina, Zdenek; Chodas, Paul W.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Sekanina, Z (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM zs@sek.jpl.nasa.gov; Paul.W.Chodas@jpl.nasa.gov
FU National Aeronautics and Space Administration
FX We thank B. G. Marsden for his comments on a draft of this paper. This
research was carried out at the Jet Propulsion Laboratory, California
Institute of Technology, under contract with the National Aeronautics
and Space Administration.
NR 18
TC 6
Z9 6
U1 0
U2 3
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD NOV 10
PY 2008
VL 687
IS 2
BP 1415
EP 1422
DI 10.1086/592081
PG 8
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 367QG
UT WOS:000260566700050
ER
PT J
AU Cuzzi, JN
Hogan, RC
Shariff, K
AF Cuzzi, Jeffrey N.
Hogan, Robert C.
Shariff, Karim
TI TOWARD PLANETESIMALS: DENSE CHONDRULE CLUMPS IN THE PROTOPLANETARY
NEBULA
SO ASTROPHYSICAL JOURNAL
LA English
DT Review
DE accretion, accretion disks; instabilities; minor planets, asteroids;
solar system: formation; turbulence
ID SOLAR NEBULA; ACCRETION DISKS; PREFERENTIAL CONCENTRATION;
GRAVITATIONAL-INSTABILITY; HYDRODYNAMIC ACCRETION; COMET 81P/WILD-2;
ASTEROID BELT; PARENT BODIES; DUST LAYER; TURBULENCE
AB We outline a scenario that traces a direct path from freely floating nebula particles to the first 10-100 km sized bodies in the terrestrial planet region, producing planetesimals that have properties matching those of primitive meteorite parent bodies. We call this "primary accretion.'' The scenario draws on elements of previous work and introduces a new critical threshold for planetesimal formation. We presume the nebula to be weakly turbulent, which leads to dense concentrations of aerodynamically size-sorted particles that have properties similar to those observed in chondrites. The fractional volume of the nebula occupied by these dense zones or clumps obeys a probability distribution as a function of their density, and the densest concentrations have particle mass densities that are 100 times that of the gas. However, even these densest clumps are prevented by gas pressure from undergoing gravitational instability in the traditional sense (on a dynamical timescale). While in this state of arrested development, they are susceptible to disruption by the ram pressure of the differentially orbiting nebula gas. However, self-gravity can preserve sufficiently large and dense clumps from ram pressure disruption, allowing their entrained particles to sediment gently but inexorably toward their centers, producing 10-100 km "sandpile'' planetesimals. Localized radial pressure fluctuations in the nebula, as well as interactions between differentially moving dense clumps, will also play a role that must be accounted for in future studies. The scenario is readily extended from meteorite parent bodies to primary accretion throughout the solar system.
C1 [Cuzzi, Jeffrey N.] Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA.
[Hogan, Robert C.] Bay Area Environm Res Inst, Sonoma, CA 95476 USA.
[Shariff, Karim] NASA, Ames Res Ctr, Adv Supercomp Div, Moffett Field, CA 94035 USA.
RP Cuzzi, JN (reprint author), Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA.
EM jeffrey.cuzzi@nasa.gov
OI Shariff, Karim/0000-0002-7256-2497
NR 109
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Z9 177
U1 0
U2 10
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD NOV 10
PY 2008
VL 687
IS 2
BP 1432
EP 1447
DI 10.1086/591239
PG 16
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 367QG
UT WOS:000260566700052
ER
PT J
AU Shariff, K
Leonard, A
Ferziger, JH
AF Shariff, Karim
Leonard, Anthony
Ferziger, Joel H.
TI A contour dynamics algorithm for axisymmetric flow
SO JOURNAL OF COMPUTATIONAL PHYSICS
LA English
DT Article
DE Contour dynamics; Vortex rings; Vorticity dynamics
ID VORTEX RINGS; QUADRATURE; VORTICITY; EVOLUTION; EQUATION; STEADY;
FAMILY; STRAIN; LAYER
AB The method of contour dynamics, developed for two-dimensional vortex patches by Zabusky et al. [N.J. Zabusky, M.H. Hughes, K.V. Roberts, Contour dynamics for the Euler equations in two-dimensions, J. Comp. Phys. 30 (1979) 96-106] is extended to vortex rings in which the vorticity distribution varies linearly with normal distance from the symmetry axis. The method tracks the motion of the boundaries of the vorticity regions and hence reduces the dimensionality of the problem by one. We discuss the formulation and implementation of the scheme, verify its accuracy and convergence, and present illustrative examples. (C) 2007 Elsevier Inc. All rights reserved.
C1 [Shariff, Karim] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
[Leonard, Anthony] CALTECH, Grad Aeronaut Labs, Pasadena, CA 91125 USA.
[Ferziger, Joel H.] Stanford Univ, Stanford, CA 94305 USA.
RP Shariff, K (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
EM kshariff@mail.arc.nasa.gov; tony@galcit.caltech.edu
OI Shariff, Karim/0000-0002-7256-2497
NR 34
TC 9
Z9 9
U1 0
U2 2
PU ACADEMIC PRESS INC ELSEVIER SCIENCE
PI SAN DIEGO
PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA
SN 0021-9991
J9 J COMPUT PHYS
JI J. Comput. Phys.
PD NOV 10
PY 2008
VL 227
IS 21
SI SI
BP 9044
EP 9062
DI 10.1016/j.jcp.2007.10.005
PG 19
WC Computer Science, Interdisciplinary Applications; Physics, Mathematical
SC Computer Science; Physics
GA 364RW
UT WOS:000260353900005
ER
PT J
AU Csatho, B
Schenk, T
Kyle, P
Wilson, T
Krabill, WB
AF Csatho, Bea
Schenk, Toni
Kyle, Philip
Wilson, Terry
Krabill, William B.
TI Airborne laser swath mapping of the summit of Erebus volcano,
Antarctica: Applications to geological mapping of a volcano
SO JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH
LA English
DT Article
DE Erebus volcano; lidar; volcanic geomorphology; DEM generation; feature
extraction
ID MOUNT EREBUS; ERUPTIVE HISTORY; ROSS ISLAND; EVOLUTION; FLOWS; LIDAR;
DEM
AB The lidar observations reported here have provided the first high precision topographic data on the active craters of Erebus volcano, Antarctica. Digital elevation data are invaluable for geomorphic analysis of volcanoes especially when combined with methods to automatically extract landscape features. The data are indispensable for studying eruptive events and volcano-tectonic processes. Airborne laser scanning or lidar is a rapidly emerging technology to map surface topography with high accuracy and detail, comparable to a 1:1000 scale map. In the austral summer of 2001-2002 airborne laser scanning data were collected in Antarctica over the summit plateau of Erebus volcano. We describe the high-resolution data set from Erebus, products derived from the data and demonstrate how extracted topographic features can be used in the geomorphic analysis of volcanoes. Background is presented on the airborne laser scanning method and on the accuracy estimation of laser points. We describe the computation of a high-resolution DEM with a grid size of 2 m x 2 m for the summit area of Erebus volcano. Errors in the DEM are assessed using independent ground-based GPS data and the RMS error is estimated to be 039 m. Visualization methods reveal topographic features that are very useful for geomorphic analysis. Automatic feature extraction and processing is necessary to exploit the high-resolution and accurate elevation data. Methods are described to extract 1D and 2D features and organize them for subsequent analysis. Fitting analytical functions to 3D point clouds or DEMs is particularly effective in extracting topographic features, including planes, higher order surfaces, cones, and conic sections. These methods are used to obtain a quantitative description of the calderas and modem-day crater of Erebus. Especially valuable are the measured surface areas if the lava lakes as these control thermal emissions and gas fluxes from the volcano. Examination of the surface elevations of Ray Lava Lake, Werner Vent and Active Vent indicates that the active vents were more or less in magmastatic equilibrium in 2001 December. Conic segments are fitted to mapped sections of caldera rims to identify the sections buried under younger lava flows or covered by ice and snow. Automatic methods are used to detect and characterize lava channels using geomorphometric maps generated from the DEM. (c) 2008 Elsevier B.V. All rights reserved.
C1 [Csatho, Bea] SUNY Buffalo, Dept Geol, Buffalo, NY 14260 USA.
[Schenk, Toni] Ohio State Univ, Dept Civil & Environm Engn & Geodet Sci, Columbus, OH 43210 USA.
[Kyle, Philip] New Mexico Inst Min & Technol, Dept Earth & Environm Sci, Socorro, NM 87801 USA.
[Wilson, Terry] Ohio State Univ, Sch Earth Sci, Columbus, OH 43210 USA.
[Krabill, William B.] NASA, Cryospher Sci Branch, GSFC, Wallops Flight Facil, Wallops Isl, VA 23337 USA.
RP Csatho, B (reprint author), SUNY Buffalo, Dept Geol, 411 Cooke Hall, Buffalo, NY 14260 USA.
EM bcsatho@buffalo.edu; schenk.2@osu.edu; kyle@nmt.edu; wilson.43@osu.edu;
william.b.krabill@nasa.gov
FU NSF [OPP-0233246, OPP-0229305, ANT-0538414]; NASA's ICESat
FX We thank members of NASA's ATM group for collecting and processing the
ATM data. Taehun Yoon (UB) and students of OSU photogrammetry group
assisted in generating the DEM. We thank Raytheon Polar Services and
especially PHI for field and helicopter support, and Mike Willis (OSU),
Beth Bartel (UNAVCO) and Mark Murray (NMT) for processing ground GPS
observations. C. Hallam (USGS) provided quality checking and
dissemination of the DEMs via the Antarctic Atlas of USGS. Reviews by
Richard Aster and Clive Oppenheimer help improve the final version of
the manuscript. BC, TS and WK were supported by NSF grant OPP-0233246
and by NASA's ICESat program. PK was supported by NSF grants OPP-0229305
and ANT-0538414. GPS data were made available by UNAVCO, Landsat and
ASTER satellite imagery and aerial photographs are from USGS.
NR 54
TC 24
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U1 1
U2 11
PU ELSEVIER SCIENCE BV
PI AMSTERDAM
PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS
SN 0377-0273
J9 J VOLCANOL GEOTH RES
JI J. Volcanol. Geotherm. Res.
PD NOV 10
PY 2008
VL 177
IS 3
BP 531
EP 548
DI 10.1016/j.jvolgeores.2008.08.016
PG 18
WC Geosciences, Multidisciplinary
SC Geology
GA 383YT
UT WOS:000261711100002
ER
PT J
AU Davies, AG
Calkins, J
Scharenbroich, L
Vaughan, RG
Wright, R
Kyle, P
Castano, R
Chien, S
Tran, D
AF Davies, Ashley Gerard
Calkins, Julie
Scharenbroich, Lucas
Vaughan, R. Greg
Wright, Robert
Kyle, Philip
Castano, Rebecca
Chien, Steve
Tran, Daniel
TI Multi-instrument remote and in situ observations of the Erebus Volcano
(Antarctica) lava lake in 2005: A comparison with the Pele lava lake on
the jovian moon Io
SO JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH
LA English
DT Article
DE Erebus; remote sensing; lo; lava lake; infrared
ID AUTONOMOUS SCIENCECRAFT EXPERIMENT; SPACEBORNE THERMAL EMISSION;
REFLECTION RADIOMETER ASTER; GALILEO NIMS DATA; SILICATE VOLCANISM;
ACTIVE VOLCANISM; MOUNT EREBUS; HEAT-FLOW; TEMPERATURE; EO-1
AB The stable, persistent, active lava lake at Erebus volcano (Ross Island, Antarctica) provides an excellent thermal target for analysis of spacecraft observations, and for testing new technology. In the austral summer of 2005 visible and infrared observations of the Erebus lava lake were obtained with sensors on three space vehicles Terra (ASTER, MODIS), Aqua (MODIS) and EO-1 (Hyperion, ALI). Contemporaneous ground-based observations were obtained with hand-held infrared cameras. This allowed a quantitative comparison of the thermal data obtained from different instruments, and of the analytical techniques used to analyze the data, both with and without the constraints imposed by ground-truth. From the thermal camera data, in December 2005 the main Erebus lava lake (Ray Lake) had an area of approximate to 820 m(2). Surface colour temperatures ranged from 575 K to 1090 K, with a broad peak in the distribution from 730 K to 850 K. Total heat loss was estimated at 23.5 MW. The flux density was approximate to 29 kW m(-2). Mass flux was estimated at 64 to 93 kg s(-1). The best correlation between thermal emission and emitting area was obtained with ASTER, which has the best combination of spatial resolution and wavelength coverage, especially in the thermal infrared. The high surface temperature of the lava lake means that Hyperion data are for the most part saturated. Uncertainties, introduced by the need to remove incident sunlight cause the thermal emission from the Hyperion data to be a factor of about two greater than that measured by hand-held thermal camera. MODIS also over-estimated thermal output from the lava lake by the same factor of two because it was detecting reflected sunlight from the rest of the pixel area. The measurement of the detailed temperature distribution on the surface of an active terrestrial lava lake will allow testing of thermal emission models used to interpret remote-sensing data of volcanism on lo, where no such ground-truth exists. Although the Erebus lava lake is four orders of magnitude smaller than the lava lake at Pele on lo, the shape of the integrated thermal emission spectra are similar. Thermal emission from this style of effusive volcanism appears to be invariant. Excess thermal emission in most Pele spectra (compared to Erebus) at short wavelengths (<3 mu m) is most likely due to disruption of the surface on the lava lake by escaping volatiles. (c) 2008 Published by Elsevier B.V.
C1 [Davies, Ashley Gerard; Scharenbroich, Lucas; Vaughan, R. Greg; Castano, Rebecca; Chien, Steve; Tran, Daniel] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[Calkins, Julie; Kyle, Philip] New Mexico Inst Min & Technol, Dept Earth & Environm Sci, Socorro, NM 87801 USA.
[Wright, Robert] Univ Hawaii Manoa, Hawaii Inst Geophys & Planetol, Honolulu, HI 96822 USA.
RP Davies, AG (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM ashley.davies@jpl.nasa.gov
RI CALKINS, JULIE/K-2668-2012
FU National Science Foundation Office of Polar Research [OPP-0229305,
ANT-0538414]; NASA Planetary Geology and Geophysics Program
FX A deployment of this kind is a complex business, and AGD thanks the many
people who helped make this possible. Firstly, the 2005 MEVO Field Team:
Philip Kyle, Nelia Dunbar, Bill Mcintosh, Julie Calkins, Kyle Jones,
Peter Kelly and Christine Kimball; Alexander Gerst (University of
Hamburg); Elizabeth Morton (Raytheon Polar Services); and Clive
Oppenheimer (Cambridge University). Also Mike Rotigliano of FUR Systems
Inc.; the National Science Foundation Office of Polar Research (Grants
OPP-0229305, ANT-0538414); Leon Maldonado, Michael Abrams and Dave Pieri
(all JPL) for planning the ASTER observations; Stuart Frye, Dan Mandl
and Lawrence Ong of the EO-1 Flight Management Team at the NASA Goddard
Space Flight Center; and Steve Saunders, manager of the NASA Planetary
Geology and Geophysics Program. AGO is supported by a grant from this
program. AGD thanks Alison Canning Davies for her meticulous review of
the manuscript prior to submission. We thank David Williams (Arizona
State University) and Clive Oppenheimer (Cambridge University) for their
reviews of the manuscript.
NR 80
TC 29
Z9 29
U1 1
U2 14
PU ELSEVIER SCIENCE BV
PI AMSTERDAM
PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS
SN 0377-0273
J9 J VOLCANOL GEOTH RES
JI J. Volcanol. Geotherm. Res.
PD NOV 10
PY 2008
VL 177
IS 3
BP 705
EP 724
DI 10.1016/j.jvolgeores.2008.02.010
PG 20
WC Geosciences, Multidisciplinary
SC Geology
GA 383YT
UT WOS:000261711100015
ER
PT J
AU Rosenqvist, L
Opgenoorth, HJ
Rastaetter, L
Vaivads, A
Dandouras, I
Buchert, S
AF Rosenqvist, L.
Opgenoorth, H. J.
Rastaetter, L.
Vaivads, A.
Dandouras, I.
Buchert, S.
TI Comparison of local energy conversion estimates from Cluster with global
MHD simulations
SO GEOPHYSICAL RESEARCH LETTERS
LA English
DT Article
ID MAGNETOHYDRODYNAMICS
AB The local energy conversion across the magnetopause has been estimated with Cluster for two magnetopause crossings. A load region, conversion from magnetic to particle energy, was identified on the dayside high-latitude magnetopause during south/dawnward IMF. Another crossing of the dawn flank magnetotail during dominantly duskward IMF was identified as a generator region where the magnetosphere is loaded with magnetic energy. The observations have been compared to results of the BATS-R-US global MHD simulation based on observed IMF conditions. BATS-R-US reproduced the magnetopause regions crossed by Cluster as a load and a generator region, correspondingly. The magnitude of the estimated energy conversion from Cluster and the model are in quite good agreement. BATS-R-US cannot reproduce the observed sharp magnetopause and some topological differences between the observations and the model occur. Citation: Rosenqvist, L., H. J. Opgenoorth, L. Rastaetter, A. Vaivads, I. Dandouras, and S. Buchert (2008), Comparison of local energy conversion estimates from Cluster with global MHD simulations, Geophys. Res. Lett., 35, L21104, doi: 10.1029/2008GL035854.
C1 [Rosenqvist, L.; Vaivads, A.; Buchert, S.] Swedish Inst Space Phys, SE-75121 Uppsala, Sweden.
[Dandouras, I.] CESR, F-31028 Toulouse, France.
[Opgenoorth, H. J.] European Space Agcy, Estec, Solar Syst Miss Div, NL-2200 AG Noordwijk, Netherlands.
[Rastaetter, L.] NASA, Goddard Space Flight Ctr, Space Weather Lab, Greenbelt, MD 20771 USA.
RP Rosenqvist, L (reprint author), Swedish Inst Space Phys, Box 537,Lagerhyddsvagen 1, SE-75121 Uppsala, Sweden.
EM lisa.rosenqvist@irfu.se
RI Rastaetter, Lutz/D-4715-2012;
OI Rastaetter, Lutz/0000-0002-7343-4147; Dandouras,
Iannis/0000-0002-7121-1118
FU Swedish National Space Board; Swedish Research Council
FX Simulation results have been provided by the Community Coordinated
Modeling Center at Goddard Space Flight Center. The BATS-R-US Model was
developed by the Center for Space Environment Modeling at the University
of Michigan. LR is supported by the Swedish National Space Board. AV is
supported by the Swedish Research Council.
NR 10
TC 10
Z9 10
U1 0
U2 1
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0094-8276
J9 GEOPHYS RES LETT
JI Geophys. Res. Lett.
PD NOV 8
PY 2008
VL 35
IS 21
AR L21104
DI 10.1029/2008GL035854
PG 6
WC Geosciences, Multidisciplinary
SC Geology
GA 370UT
UT WOS:000260789300003
ER
PT J
AU Li, RX
Wu, B
Di, K
Angelova, A
Arvidson, RE
Lee, IC
Maimone, M
Matthies, LH
Richer, L
Sullivan, R
Sims, MH
Greenberger, R
Squyres, SW
AF Li, Rongxing
Wu, Bo
Di, Kaichang
Angelova, Anelia
Arvidson, Raymond E.
Lee, I-Chieh
Maimone, Mark
Matthies, Larry H.
Richer, Lutz
Sullivan, Robert
Sims, Michael H.
Greenberger, Rebecca
Squyres, Steven W.
TI Characterization of traverse slippage experienced by Spirit rover on
Husband Hill at Gusev crater
SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS
LA English
DT Article
ID MARS EXPLORATION ROVERS; MERIDIANI-PLANUM; VISUAL ODOMETRY;
LOCALIZATION; OPPORTUNITY; MISSION
AB Spirit rover experienced significant slips traversing Husband Hill. This paper analyzes the slippage Spirit experienced from Sol 154 to Sol 737. Slippage with respect to terrain type and slope is computed using data downlinked from the rover, rover position, and orientation estimations from visual odometry (VO) and photogrammetry based bundle adjustment (BA) method. Accumulated slippage reached a maximum of 83.86 m on Sol 648. However, as Spirit descended into the Inner Basin, the direction of slippage reversed, and accumulated slippage approached zero by the end of the entire traverse. Eight local regions with significant slips and nineteen traverse segments have been analyzed. Slippage was found to be highly correlated to slope direction and magnitude; the reverse of slope directions in the ascending and descending portions of the traverse proves to be the main contributor to the observed cancellation of slippage. While the horizontal component of the slippage almost canceled out, the difference in elevation continually accumulated, mainly during the ascent. In general, long traverse segments created more slips than short ones. This is reflected in both the accumulated and individual slippages. In considering the four major Mars terrain types, Spirit performed best on bedrock, managing to drive on slopes close to 30 degrees. Fine-grain surfaces were the most challenging; though progress was made on slopes up to 15 degrees, slippages of over 100% (more slippage than distance traveled) occurred for short segments. The results of this work can be incorporate into a traverse planning framework in which rover slippage is minimized. Results can be employed in landed planetary missions for precision navigation to avoid potentially dangerous regions by considering expected slippage.
C1 [Li, Rongxing; Wu, Bo; Di, Kaichang; Lee, I-Chieh] Ohio State Univ, Dept Civil & Environm Engn & Geodet Sci, Mapping & GIS Lab, Columbus, OH 43210 USA.
[Angelova, Anelia] CALTECH, Dept Comp Sci, Pasadena, CA 91125 USA.
[Arvidson, Raymond E.; Greenberger, Rebecca] Washington Univ, Dept Earth & Planetary Sci, St Louis, MO 63130 USA.
[Maimone, Mark; Matthies, Larry H.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[Richer, Lutz] DLR, Inst Space Simulat, D-51170 Cologne, Germany.
[Sims, Michael H.] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
[Sullivan, Robert; Squyres, Steven W.] Cornell Univ, Dept Astron, Ithaca, NY 14853 USA.
RP Li, RX (reprint author), Ohio State Univ, Dept Civil & Environm Engn & Geodet Sci, Mapping & GIS Lab, 470 Hitchcock Hall,2070 Neil Ave, Columbus, OH 43210 USA.
EM li.282@osu.edu
RI Wu, Bo/J-6177-2012;
OI Wu, Bo/0000-0001-9530-3044; Greenberger, Rebecca/0000-0003-1583-0261
FU Mars Exploration Program of NASA
FX This work was partially performed at the Jet Propulsion Laboratory,
California Institute of Technology, under a contract with the National
Aeronautics and Space Administration. Funding of this research by the
Mars Exploration Program of NASA is acknowledged.
NR 30
TC 7
Z9 7
U1 0
U2 2
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 2169-9097
EI 2169-9100
J9 J GEOPHYS RES-PLANET
JI J. Geophys. Res.-Planets
PD NOV 8
PY 2008
VL 113
IS E12
AR E12S35
DI 10.1029/2008JE003097
PG 16
WC Geochemistry & Geophysics
SC Geochemistry & Geophysics
GA 370UC
UT WOS:000260787600001
ER
PT J
AU Harries, J
Carli, B
Rizzi, R
Serio, C
Mlynczak, M
Palchetti, L
Maestri, T
Brindley, H
Masiello, G
AF Harries, J.
Carli, B.
Rizzi, R.
Serio, C.
Mlynczak, M.
Palchetti, L.
Maestri, T.
Brindley, H.
Masiello, G.
TI THE FAR-INFRARED EARTH
SO REVIEWS OF GEOPHYSICS
LA English
DT Review
ID FOURIER-TRANSFORM SPECTROMETER; STRATOSPHERIC SUBMILLIMETER LINES;
MOLECULAR SPECTROSCOPIC DATABASE; EMITTED RADIANCE INTERFEROMETER;
DOWNWELLING SPECTRAL RADIANCE; GENERAL-CIRCULATION MODELS; CLIMATE
FEEDBACK PROCESSES; WATER-VAPOR; RADIATION BUDGET; CIRRUS CLOUDS
AB The paper presents a review of the far-infrared (FIR) properties of the Earth's atmosphere and their role in climate. These properties have been relatively poorly understood, and it is one of the purposes of this review to demonstrate that in recent years we have made great strides in improving this understanding. Seen from space, the Earth is a cool object, with an effective emitting temperature of about 255 K. This contrasts with a global mean surface temperature of similar to 288 K and is due primarily to strong absorption of outgoing longwave energy by water vapor, carbon dioxide, and clouds (especially ice). A large fraction of this absorption occurs in the FIR, and so the Earth is effectively a FIR planet. The FIR is important in a number of key climate processes, for example, the water vapor and cloud feedbacks (especially ice clouds). The FIR is also a spectral region which can be used to remotely sense and retrieve atmospheric composition in the presence of ice clouds. Recent developments in instrumentation have allowed progress in each of these areas, which are described, and proposals for a spaceborne FIR instrument are being formulated. It is timely to review the FIR properties of the clear and cloudy atmosphere, the role of FIR processes in climate, and its use in observing our planet from space.
C1 [Harries, J.; Brindley, H.] Univ London Imperial Coll Sci Technol & Med, Blackett Lab, London SW7 2AZ, England.
[Carli, B.; Palchetti, L.] CNR, Ist Fisica Applicata Nello Carrara, I-50019 Sesto Fiorentino, Italy.
[Rizzi, R.; Maestri, T.] Univ Bologna, Atmospher Dynam Grp, Dipartimento Fis, I-40127 Bologna, Italy.
[Serio, C.; Masiello, G.] Univ Basilicata, Dipartimento Ingn & Fis Ambiente, I-85100 Potenza, Italy.
[Mlynczak, M.] NASA, Langley Res Ctr, Hampton, VA 23687 USA.
RP Harries, J (reprint author), Univ London Imperial Coll Sci Technol & Med, Blackett Lab, Prince Consort Rd, London SW7 2AZ, England.
EM j.harries@ic.ac.uk
RI Mlynczak, Martin/K-3396-2012; Rizzi, Rolando/L-3556-2013; Masiello,
Guido/I-6459-2015; PALCHETTI, LUCA/O-1270-2015;
OI Masiello, Guido/0000-0002-7986-8296; PALCHETTI,
LUCA/0000-0003-4022-8125; Brindley, Helen/0000-0002-7859-9207; RIZZI,
ROLANDO/0000-0001-7792-7806; Serio, Carmine/0000-0002-5931-7681
NR 143
TC 35
Z9 35
U1 0
U2 19
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 8755-1209
J9 REV GEOPHYS
JI Rev. Geophys.
PD NOV 8
PY 2008
VL 46
IS 4
AR RG4004
DI 10.1029/2007RG000233
PG 34
WC Geochemistry & Geophysics
SC Geochemistry & Geophysics
GA 370TI
UT WOS:000260785600001
ER
PT J
AU Zhang, J
Richardson, IG
Webb, DF
AF Zhang, J.
Richardson, I. G.
Webb, D. F.
TI Interplanetary origin of multiple-dip geomagnetic storms
SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
LA English
DT Article
ID CORONAL MASS EJECTIONS; SOLAR-WIND; MAGNETIC-FIELD; COMPLEX EJECTA;
CLOUDS; SIGNATURES; REGIONS; SHOCKS; PHASE; DECAY
AB In this paper, we have systematically investigated the interplanetary drivers of major dips during intense (Dst <= -100 nT) geomagnetic storms in 1996-2006. A major dip is defined as a temporary decrease in Dst index with amplitude larger than 14.5 nT. Multiple dips result in a storm if regions of geoeffective solar wind with strong southward magnetic fields are separated by less geoeffective solar wind. Among these 90 intense storms, we found that only 34% (31 events) showed a classical "one-dip'' profile, while 49% (44 events) had two dips. Another 17% (15 events) had triple or more dips. We found that of a total of 165 major dips associated with the 90 storms, about 45% (74 dips) were caused by interplanetary coronal mass ejections (ICMEs), or ejecta, and 30% (49 dips) were caused by sheaths (SHs) that lie between shocks driven by ICMEs and leading edges of the ICMEs. About 7% (11 dips) were caused by a shock driven by an ICME running into a preceding ICME and intensifying its magnetic field (PICME-SH). About 11% (18 dips) were due to corotating interaction regions (CIRs) formed by the interaction of high-speed solar wind from coronal holes with the preceding slower solar wind. Another 7% (12 dips) were caused by various solar wind structures prior the onset of the storm. Among these different types of drivers, the largest storms dips on average were produced by shocks propagating through preceding ICMEs (PICME-SH). One frequent cause of a two-dip storm is that the first dip is produced by the upstream sheath and the second dip is produced by the driving ICME. Another common cause of a two-dip or multiple-dip storm is the presence of multiple subregions of southward magnetic field within a complex solar wind flow, resulting from two successive, closely spaced ICMEs.
C1 [Zhang, J.] George Mason Univ, Dept Computat & Data Sci, Fairfax, VA 22030 USA.
[Richardson, I. G.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
[Webb, D. F.] Boston Coll, Inst Sci Res, Chestnut Hill, MA 02467 USA.
[Richardson, I. G.] Univ Maryland, CRESST, College Pk, MD 20742 USA.
[Richardson, I. G.] Univ Maryland, Dept Astron, College Pk, MD 20742 USA.
RP Zhang, J (reprint author), George Mason Univ, Dept Computat & Data Sci, 4400 Univ Dr,MSN 6A2, Fairfax, VA 22030 USA.
EM jzhang7@gmu.edu; ian.g.richardson@nasa.gov;
david.webb.ctr@hanscom.af.mil
OI Richardson, Ian/0000-0002-3855-3634
FU NASA [NNG04GN36G, NNG05GG19G]; NSF SHINE [ATM-0454612]; NASA
Heliospheric Guest Investigator; AFRL [FA8718-06-C-0015]
FX The ACE plasma and magnetic field data are provided by GSFC Space
Physics Data Facility. J. Z. acknowledges the support from NASA grants
NNG04GN36G and NNG05GG19G and NSF SHINE grant ATM-0454612. I. G. R.
acknowledges a NASA Heliospheric Guest Investigator grant. D. F. W. was
supported by AFRL contract FA8718-06-C-0015.
NR 38
TC 13
Z9 13
U1 0
U2 2
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 2169-9380
J9 J GEOPHYS RES-SPACE
JI J. Geophys. Res-Space Phys.
PD NOV 7
PY 2008
VL 113
AR A00A12
DI 10.1029/2008JA013228
PG 12
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 370TN
UT WOS:000260786100001
ER
PT J
AU Williams, CA
Hanan, NP
Baker, I
Collatz, GJ
Berry, J
Denning, AS
AF Williams, Christopher A.
Hanan, Niall P.
Baker, Ian
Collatz, G. James
Berry, Joseph
Denning, A. Scott
TI Interannual variability of photosynthesis across Africa and its
attribution
SO JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES
LA English
DT Article
ID TERRESTRIAL BIOPHYSICAL PARAMETERS; NET PRIMARY PRODUCTION; GLOBAL
CARBON-CYCLE; ATMOSPHERIC CO2; STOMATAL CONDUCTANCE; RAINFALL
VARIABILITY; SPATIAL-RESOLUTION; SATELLITE DATA; NDVI DATA; CLIMATE
AB Africa is thought to be a large source of interannual variability in the global carbon cycle, only vaguely attributed to climate fluctuations. This study uses a biophysical model, Simple Biosphere, to examine in detail what specific factors, physiological (acute stress from low soil water, temperature, or low humidity) and biophysical (low vegetation radiation use), are responsible for spatiotemporal patterns of photosynthesis across the African continent during the period 1982-2003. Acute soil water stress emerges as the primary factor driving interannual variability of photosynthesis for most of Africa. Southern savannas and woodlands are a particular hot spot of interannual variability in photosynthesis, owing to high rainfall variability and photosynthetic potential but intermediate annual rainfall. Surprisingly low interannual variability of photosynthesis in much of the Sudano-Sahelian zone derives from relatively low vegetation cover, pronounced humidity stress, and somewhat lower rainfall variability, whereas perennially wet conditions diminish interannual variability in photosynthesis across much of the Congo Basin and coastal West Africa. Though not of focus here, the coefficient of variation in photosynthesis is notably high in drylands and desert margins (i.e., Sahel, Greater Horn, Namib, and Kalahari) having implications for supply of food and fiber. These findings emphasize that when considering impacts of climate change and land surface feedbacks to the atmosphere, it is important to recognize how vegetation, climate, and soil characteristics may conspire to filter or dampen ecosystem responses to hydroclimatic variability.
C1 [Williams, Christopher A.] Clark Univ, Grad Sch Geog, Worcester, MA 01610 USA.
[Hanan, Niall P.] Colorado State Univ, Nat Resource Ecol Lab, Ft Collins, CO 80523 USA.
[Baker, Ian; Denning, A. Scott] Colorado State Univ, Dept Atmospher Sci, Ft Collins, CO 80523 USA.
[Berry, Joseph] Carnegie Inst Sci, Washington, DC 20005 USA.
[Collatz, G. James] NASA, Goddard Space Flight Ctr, Biospher Sci Branch, Hydrospher & Biospher Sci Lab, Greenbelt, MD 20771 USA.
RP Williams, CA (reprint author), Clark Univ, Grad Sch Geog, 950 Main St, Worcester, MA 01610 USA.
EM cwilliams@clarku.edu
RI collatz, george/D-5381-2012; Denning, Scott/F-4974-2011;
OI Denning, Scott/0000-0003-3032-7875; Hanan, Niall/0000-0002-9130-5306
FU United States National Aeronautics and Space Administration (NASA);
National Oceanic and Atmospheric Administration (DOAA)
FX Funding for this study was provided by the United States National
Aeronautics and Space Administration (NASA) Terrestrial Ecology Program
(Diane Wickland) and the National Oceanic and Atmospheric Administration
(DOAA) Global Carbon Cycle Program (Kathy Tedesco).
NR 62
TC 20
Z9 22
U1 0
U2 17
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 2169-8953
EI 2169-8961
J9 J GEOPHYS RES-BIOGEO
JI J. Geophys. Res.-Biogeosci.
PD NOV 6
PY 2008
VL 113
IS G4
AR G04015
DI 10.1029/2008JG000718
PG 15
WC Environmental Sciences; Geosciences, Multidisciplinary
SC Environmental Sciences & Ecology; Geology
GA 370UJ
UT WOS:000260788300001
ER
PT J
AU Arvidson, RE
Ruff, SW
Morris, RV
Ming, DW
Crumpler, LS
Yen, AS
Squyres, SW
Sullivan, RJ
Bell, JF
Cabrol, NA
Clark, BC
Farrand, WH
Gellert, R
Greenberger, R
Grant, JA
Guinness, EA
Herkenhoff, KE
Hurowitz, JA
Johnson, JR
Klingelhofer, G
Lewis, KW
Li, R
McCoy, TJ
Moersch, J
McSween, HY
Murchie, SL
Schmidt, M
Schroder, C
Wang, A
Wiseman, S
Madsen, MB
Goetz, W
McLennan, SM
AF Arvidson, R. E.
Ruff, S. W.
Morris, R. V.
Ming, D. W.
Crumpler, L. S.
Yen, A. S.
Squyres, S. W.
Sullivan, R. J.
Bell, J. F., III
Cabrol, N. A.
Clark, B. C.
Farrand, W. H.
Gellert, R.
Greenberger, R.
Grant, J. A.
Guinness, E. A.
Herkenhoff, K. E.
Hurowitz, J. A.
Johnson, J. R.
Klingelhoefer, G.
Lewis, K. W.
Li, R.
McCoy, T. J.
Moersch, J.
McSween, H. Y.
Murchie, S. L.
Schmidt, M.
Schroeder, C.
Wang, A.
Wiseman, S.
Madsen, M. B.
Goetz, W.
McLennan, S. M.
TI Spirit Mars Rover Mission to the Columbia Hills, Gusev Crater: Mission
overview and selected results from the Cumberland Ridge to Home Plate
SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS
LA English
DT Article
ID KILAUEA VOLCANO; SOILS; REFLECTANCE; TEPHRA; ROCKS
AB This paper summarizes the Spirit rover operations in the Columbia Hills of Gusev Crater from sols 513 to 1476 and provides an overview of selected findings that focus on synergistic use of the Athena Payload and comparisons to orbital data. Results include discovery of outcrops (Voltaire) on Husband Hill that are interpreted to be altered impact melt deposits that incorporated local materials during emplacement. Evidence for extensive volcanic activity and aqueous alteration in the Inner Basin is also detailed, including discovery and characterization of accretionary lapilli and formation of sulfate, silica, and hematite-rich deposits. Use of Spirit's data to understand the range of spectral signatures observed over the Columbia Hills by the Mars Reconnaissance Orbiter's Compact Reconnaissance Imaging Spectrometer (CRISM) hyperspectral imager (0.4-4 mu m) is summarized. We show that CRISM spectra are controlled by the proportion of ferric-rich dust to ferrous-bearing igneous minerals exposed in ripples and other windblown deposits. The evidence for aqueous alteration derived from Spirit's data is associated with outcrops that are too small to be detected from orbital observations or with materials exposed from the shallow subsurface during rover activities. Although orbital observations show many other locations on Mars with evidence for minerals formed or altered in an aqueous environment, Spirit's data imply that the older crust of Mars has been altered even more extensively than evident from orbital data. This result greatly increases the potential that the surface or shallow subsurface was once a habitable regime.
C1 [Arvidson, R. E.; Greenberger, R.; Guinness, E. A.; Wang, A.; Wiseman, S.] Washington Univ, Dept Earth & Planetary Sci, St Louis, MO 63130 USA.
[Squyres, S. W.; Sullivan, R. J.; Bell, J. F., III] Cornell Univ, Dept Astron, Ithaca, NY 14853 USA.
[Clark, B. C.] Lockheed Martin Corp, Littleton, CO 80125 USA.
[Cabrol, N. A.] NASA, Ames SETI Inst, Moffett Field, CA 94035 USA.
[Crumpler, L. S.] New Mexico Museum Nat Hist & Sci, Albuquerque, NM 87104 USA.
[Farrand, W. H.] Space Sci Inst, Boulder, CO 80301 USA.
[Gellert, R.] Univ Guelph, Dept Phys, Guelph, ON N1G 2W1, Canada.
[Goetz, W.] Max Planck Inst Sonnensyst Forsch, D-37191 Katlenburg Lindau, Germany.
[Grant, J. A.] Smithsonian Inst, Natl Air & Space Museum, Ctr Earth & Planetary Studies, Washington, DC 20013 USA.
[Herkenhoff, K. E.; Johnson, J. R.] US Geol Survey, Flagstaff, AZ 86001 USA.
[Yen, A. S.; Hurowitz, J. A.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[Klingelhoefer, G.] Johannes Gutenberg Univ Mainz, Inst Anorgan & Analyt Chem, D-55099 Mainz, Germany.
[Lewis, K. W.] CALTECH, Pasadena, CA 91125 USA.
[Li, R.; Schmidt, M.] Ohio State Univ, Dept Civil & Environm Engn & Geodet Sci, Columbus, OH 43210 USA.
[Madsen, M. B.] Univ Copenhagen, Niels Bohr Inst, DK-2100 Copenhagen, Denmark.
[McCoy, T. J.] Smithsonian Inst, Dept Mineral Sci, Washington, DC 20013 USA.
[McLennan, S. M.] SUNY Stony Brook, Dept Geosci, Stony Brook, NY 11794 USA.
[Moersch, J.; McSween, H. Y.] Univ Tennessee, Dept Earth & Planetary Sci, Knoxville, TN 37996 USA.
[Morris, R. V.; Ming, D. W.; Schroeder, C.] NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA.
[Murchie, S. L.] Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA.
[Ruff, S. W.] Arizona State Univ, Sch Earth & Space Explorat, Tempe, AZ 85287 USA.
RP Arvidson, RE (reprint author), Washington Univ, Dept Earth & Planetary Sci, 1 Brookings Dr, St Louis, MO 63130 USA.
EM arvidson@rsmail.wustl.edu
RI Schroder, Christian/B-3870-2009; Moersch, Jeffrey/F-7189-2010; Lewis,
Kevin/E-5557-2012; Madsen, Morten/D-2082-2011; Murchie,
Scott/E-8030-2015; Johnson, Jeffrey/F-3972-2015;
OI Schroder, Christian/0000-0002-7935-6039; Madsen,
Morten/0000-0001-8909-5111; Murchie, Scott/0000-0002-1616-8751;
Greenberger, Rebecca/0000-0003-1583-0261
FU Johnson Space Center, administered by Oak Ridge Associated Universities;
NASA
FX We thank the capable team of engineers and scientists who made the
Spirit mission possible, and we thank NASA for its support of our
endeavors and the HiRISE, CTX, and CRISM teams who worked to acquire,
process, and release the orbital data used in this study. We also thank
Bethany Ehlmann and Horton Newsom for thoughtful reviews. C. S.
specifically acknowledges support by an appointment to the NASA
Postdoctoral Program at the Johnson Space Center, administered by Oak
Ridge Associated Universities through a contract with NASA.
NR 48
TC 59
Z9 61
U1 1
U2 16
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 2169-9097
EI 2169-9100
J9 J GEOPHYS RES-PLANET
JI J. Geophys. Res.-Planets
PD NOV 6
PY 2008
VL 113
IS E12
AR E12S33
DI 10.1029/2008JE003183
PG 35
WC Geochemistry & Geophysics
SC Geochemistry & Geophysics
GA 370UB
UT WOS:000260787500003
ER
PT J
AU Herkenhoff, KE
Grotzinger, J
Knoll, AH
McLennan, SM
Weitz, C
Yingst, A
Anderson, R
Archinal, BA
Arvidson, RE
Barrett, JM
Becker, KJ
Bell, JF
Budney, C
Chapman, MG
Cook, D
Ehlmann, B
Franklin, B
Gaddis, LR
Galuszka, DM
Garcia, PA
Geissler, P
Hare, TM
Howington-Kraus, E
Johnson, JR
Keszthelyi, L
Kirk, RL
Lanagan, P
Lee, EM
Leff, C
Maki, JN
Mullins, KF
Parker, TJ
Redding, BL
Rosiek, MR
Sims, MH
Soderblom, LA
Spanovich, N
Springer, R
Squyres, SW
Stolper, D
Sucharski, RM
Sucharski, T
Sullivan, R
Torson, JM
AF Herkenhoff, Ken E.
Grotzinger, John
Knoll, Andrew H.
McLennan, Scott M.
Weitz, Catherine
Yingst, Aileen
Anderson, Robert
Archinal, Brent A.
Arvidson, Raymond E.
Barrett, Janet M.
Becker, Kris J.
Bell, James F., III
Budney, Charles
Chapman, Mary G.
Cook, Debbie
Ehlmann, Bethany
Franklin, Brenda
Gaddis, Lisa R.
Galuszka, Donna M.
Garcia, Patricia A.
Geissler, Paul
Hare, Trent M.
Howington-Kraus, Elpitha
Johnson, Jeffrey R.
Keszthelyi, Laszlo
Kirk, Randolph L.
Lanagan, Peter
Lee, Ella Mae
Leff, Craig
Maki, Justin N.
Mullins, Kevin F.
Parker, Timothy J.
Redding, Bonnie L.
Rosiek, Mark R.
Sims, Michael H.
Soderblom, Laurence A.
Spanovich, Nicole
Springer, Richard
Squyres, Steve W.
Stolper, Daniel
Sucharski, Robert M.
Sucharski, Tracie
Sullivan, Rob
Torson, James M.
TI Surface processes recorded by rocks and soils on Meridiani Planum, Mars:
Microscopic Imager observations during Opportunity's first three
extended missions
SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS
LA English
DT Article
ID LANDING SITE; MOSSBAUER SPECTROMETER; BURNS FORMATION; ROVER;
ENVIRONMENT; DIAGENESIS; MINERALOGY; CHEMISTRY; ORIGIN; CRATER
AB The Microscopic Imager (MI) on the Mars Exploration Rover Opportunity has returned images of Mars with higher resolution than any previous camera system, allowing detailed petrographic and sedimentological studies of the rocks and soils at the Meridiani Planum landing site. Designed to simulate a geologist's hand lens, the MI is mounted on Opportunity's instrument arm and can resolve objects 0.1 mm across or larger. This paper provides an overview of MI operations, data calibration, and analysis of MI data returned during the first 900 sols (Mars days) of the Opportunity landed mission. Analyses of Opportunity MI data have helped to resolve major questions about the origin of observed textures and features. These studies support eolian sediment transport, rather than impact surge processes, as the dominant depositional mechanism for Burns formation strata. MI stereo observations of a rock outcrop near the rim of Erebus Crater support the previous interpretation of similar sedimentary structures in Eagle Crater as being formed by surficial flow of liquid water. Well-sorted spherules dominate ripple surfaces on the Meridiani plains, and the size of spherules between ripples decreases by about 1 mm from north to south along Opportunity's traverse between Endurance and Erebus craters.
C1 [Herkenhoff, Ken E.; Archinal, Brent A.; Barrett, Janet M.; Becker, Kris J.; Chapman, Mary G.; Cook, Debbie; Gaddis, Lisa R.; Galuszka, Donna M.; Garcia, Patricia A.; Geissler, Paul; Hare, Trent M.; Howington-Kraus, Elpitha; Johnson, Jeffrey R.; Keszthelyi, Laszlo; Kirk, Randolph L.; Lee, Ella Mae; Mullins, Kevin F.; Redding, Bonnie L.; Rosiek, Mark R.; Soderblom, Laurence A.; Sucharski, Robert M.; Sucharski, Tracie; Torson, James M.] US Geol Survey, Astrogeol Team, Flagstaff, AZ 86001 USA.
[Arvidson, Raymond E.; Ehlmann, Bethany] Washington Univ, Dept Earth & Planetary Sci, St Louis, MO 63130 USA.
[Bell, James F., III; Squyres, Steve W.; Sullivan, Rob] Cornell Univ, Dept Astron, Ithaca, NY 14853 USA.
[Grotzinger, John; Stolper, Daniel] CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA.
[Knoll, Andrew H.] Harvard Univ, Dept Organism & Evolutionary Biol, Cambridge, MA 02138 USA.
[Lanagan, Peter] Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA.
[McLennan, Scott M.] SUNY Stony Brook, Dept Geosci, Stony Brook, NY 11794 USA.
[Sims, Michael H.] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
[Weitz, Catherine] Planetary Sci Inst, Tucson, AZ 85719 USA.
[Yingst, Aileen] Univ Wisconsin, Dept Nat & Appl Sci, Green Bay, WI 54311 USA.
[Anderson, Robert; Budney, Charles; Franklin, Brenda; Leff, Craig; Maki, Justin N.; Parker, Timothy J.; Spanovich, Nicole; Springer, Richard] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Herkenhoff, KE (reprint author), US Geol Survey, Astrogeol Team, Flagstaff, AZ 86001 USA.
EM kherkenhoff@usgs.gov
RI Johnson, Jeffrey/F-3972-2015;
OI Hare, Trent/0000-0001-8842-389X
NR 49
TC 16
Z9 16
U1 1
U2 9
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 2169-9097
EI 2169-9100
J9 J GEOPHYS RES-PLANET
JI J. Geophys. Res.-Planets
PD NOV 6
PY 2008
VL 113
IS E12
AR E12S32
DI 10.1029/2008JE003100
PG 39
WC Geochemistry & Geophysics
SC Geochemistry & Geophysics
GA 370UB
UT WOS:000260787500002
ER
PT J
AU Zahnle, K
Haberle, RM
Catling, DC
Kasting, JF
AF Zahnle, Kevin
Haberle, Robert M.
Catling, David C.
Kasting, James F.
TI Photochemical instability of the ancient Martian atmosphere
SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS
LA English
DT Article
ID EARTHS EARLY ATMOSPHERE; EVALUATED KINETIC-DATA; LYMAN-ALPHA DATA; EARLY
MARS; TEMPERATURE-DEPENDENCE; SULFUR ISOTOPES; OXIDATION-STATE;
CARBON-DIOXIDE; OXYGEN-ATOMS; HYDROGEN
AB We develop a 1-D steady state photochemical model of the modern Martian atmosphere and apply it to possible Martian atmospheres present and past. A unique feature of our model is that the major current sink of oxygen is dry deposition (surface reactions) of highly reactive, oxidized molecules (chiefly H2O2), rather than oxygen escape to space. Another difference is that we allow hydrogen to escape to space at the diffusion limit, which gives H escape fluxes similar to 70% higher than in other models. What results is a model with one free parameter: a dry deposition velocity to describe the surface sink of reactive molecules. An effective global average deposition velocity of 0.02 cm s(-1) for H2O2 and O-3 gives a good match to the observed abundances of O-2, CO, and H-2, the three abundant photochemical trace gases. We then apply our model to Martian atmospheres with different amounts of CO2, H2O, and solar forcing. We find that thick, cold, dry CO2 atmospheres are photochemically unstable with respect to conversion to CO. This may be pertinent to ancient Mars when the Sun was faint and O escape rates were likely high, for which the tipping point is computed to be similar to 10 mbar of CO2. The possible photochemical instability of cold thick CO2 atmospheres, and the high likelihood that CO was abundant even if CO2 were stable, has broad implications for early Mars.
C1 [Zahnle, Kevin; Haberle, Robert M.] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
[Catling, David C.] Univ Bristol, Dept Earth Sci, Bristol BS8 1RJ, Avon, England.
[Kasting, James F.] Penn State Univ, Dept Geosci, University Pk, PA 16802 USA.
RP Zahnle, K (reprint author), NASA, Ames Res Ctr, MS 245-3, Moffett Field, CA 94035 USA.
EM kzahnle@mail.arc.nasa.gov
RI Catling, David/D-2082-2009;
OI Catling, David/0000-0001-5646-120X
FU EU Marie Curie Chair
FX We thank Mark Claire, Pat Hamill, and Robert Chatfield for helpful
improvements of the photochemical code. We also thank Darrell Strobel,
Bob Johnson, Roger Yelle, and Jun Cui for discussions, insightful
comments, and prepublication manuscripts addressing problems related to
diffusion-limited escape. We thank NASA's Exobiology Program, Planetary
Atmospheres Program, and the Mars Fundamental Research Program for
support. D. C. also acknowledges the support of an EU Marie Curie Chair.
NR 86
TC 40
Z9 43
U1 2
U2 19
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 2169-9097
EI 2169-9100
J9 J GEOPHYS RES-PLANET
JI J. Geophys. Res.-Planets
PD NOV 6
PY 2008
VL 113
IS E11
AR E11004
DI 10.1029/2008JE003160
PG 16
WC Geochemistry & Geophysics
SC Geochemistry & Geophysics
GA 370TZ
UT WOS:000260787300002
ER
PT J
AU Randles, CA
Ramaswamy, V
AF Randles, C. A.
Ramaswamy, V.
TI Absorbing aerosols over Asia: A Geophysical Fluid Dynamics Laboratory
general circulation model sensitivity study of model response to aerosol
optical depth and aerosol absorption
SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
LA English
DT Article
ID BLACK CARBON AEROSOLS; SEA THERMAL CONTRAST; SUMMER MONSOON; ACE-ASIA;
TROPOSPHERIC AEROSOL; HYDROLOGICAL CYCLE; RELATIVE-HUMIDITY; CLIMATE;
CHINA; SURFACE
AB Forcing by absorbing atmospheric black carbon (BC) tends to heat the atmosphere, cool the surface, and reduce the surface latent and sensible heat fluxes. BC aerosol can have a large impact on regional climates and the hydrologic cycle. However, significant uncertainties remain concerning the increases in (1) the total amount of all aerosol species and (2) the amount of aerosol absorption that may have occurred over the 1950-1990 period. Focusing on south and east Asia, the sensitivity of a general circulation model's climate response (with prescribed sea surface temperatures and aerosol distributions) to such changes is investigated by considering a range of both aerosol absorption and aerosol extinction optical depth increases. We include direct and semidirect aerosol effects only. Precipitation changes are less sensitive to changes in aerosol absorption optical depth at lower aerosol loadings. At higher-extinction optical depths, low-level convergence and increases in vertical velocity overcome the stabilizing effects of absorbing aerosols and enhance the monsoonal circulation and precipitation in northwestern India. In contrast, the presence of increases in only scattering aerosols weakens the monsoonal circulation and inhibits precipitation here. Cloud amount changes can enhance or counteract surface solar flux reduction depending on the aerosol loading and absorption, with the changes also influencing the surface temperature and the surface energy balance. The results have implications for aerosol reduction strategies in the future that seek to mitigate air pollution concerns. At higher optical depths, if absorbing aerosol is present, reduction of scattering aerosol alone has a reduced effect on precipitation changes, implying that reductions in BC aerosols should be undertaken at the same time as reductions in sulfate aerosols.
C1 [Ramaswamy, V.] NOAA, Geophys Fluid Dynam Lab, Princeton, NJ 08540 USA.
[Randles, C. A.; Ramaswamy, V.] Princeton Univ, Atmospher & Ocean Sci Program, Princeton, NJ 08544 USA.
RP Randles, CA (reprint author), NASA, Goddard Space Flight Ctr, Code 613-3,Bldg 33 Room 311,Mailstop 613-3, Greenbelt, MD 20771 USA.
EM crandles@umbc.edu; V.Ramaswamy@noaa.gov
RI Randles, Cynthia/B-6972-2013
NR 67
TC 53
Z9 53
U1 2
U2 21
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 2169-897X
EI 2169-8996
J9 J GEOPHYS RES-ATMOS
JI J. Geophys. Res.-Atmos.
PD NOV 5
PY 2008
VL 113
IS D21
AR D21203
DI 10.1029/2008JD010140
PG 20
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 370UL
UT WOS:000260788500007
ER
PT J
AU Chambers, DP
Willis, JK
AF Chambers, Don P.
Willis, Josh K.
TI Analysis of large-scale ocean bottom pressure variability in the North
Pacific
SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
LA English
DT Article
ID MEAN SEA-LEVEL; WATER MASS BUDGET; SURFACE TEMPERATURES; GLOBAL OCEAN;
TOPEX/POSEIDON; MODEL; ASSIMILATION; CIRCULATION; ATLANTIC; GRACE
AB We use the leading empirical orthogonal functions (EOFs) of ocean bottom pressure (OBP) derived from an ocean model and the technique of EOF reconstruction to reduce noise in the large-scale OBP variations derived from the Gravity Recovery and Climate Experiment (GRACE). The subsequent OBP variations from the model and GRACE are then examined in the North Pacific between January 2003 and May 2007. Although annual and semiannual variations are similar, GRACE observes large interannual fluctuations poleward of 30 degrees, where OBP increases from a low of nearly 3 cm below normal in early 2003 to normal throughout 2004 and 2005, then an increase of nearly the same magnitude in 2006. These fluctuations have also been observed in OBP inferred from satellite altimetry corrected for steric variations computed from Argo float data. Since GRACE and steric-corrected altimetry are completely independent observations of OBP, we conclude that the model has errors or deficiencies in predicting the interannual OBP fluctuations in the North Pacific.
C1 [Chambers, Don P.] Univ Texas Austin, Ctr Space Res, Austin, TX 78759 USA.
[Willis, Josh K.] CALTECH, NASA, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Chambers, DP (reprint author), Univ Texas Austin, Ctr Space Res, 3925 W Braker Lane,Suite 200, Austin, TX 78759 USA.
EM chambers@csr.utexas.edu
OI Chambers, Don/0000-0002-5439-0257
FU National Oceanographic Partnership Program; CNES; NASA GRACE Science
Team
FX We would like to thank I. Fukumori for providing the output of the
JPL_ECCO runs and for useful discussions on this paper. The data are a
contribution of the Consortium for Estimating the Circulation and
Climate of the Ocean (ECCO) funded by the National Oceanographic
Partnership Program. GRACE data were processed under NASA Earth Science
REASoN GRACE Project and are available at http://grace.jpl.nasa.gov. The
altimeter products were produced by Ssalto/Duacs and distributed by
AVISO with support from CNES and are available at
http://www.aviso.oceanobs.com/en/data. The float data were collected and
made freely available by the International Argo Project (a pilot program
of the Global Ocean Observing System) and contributing national programs
and are available at http://www.argo.net. Finally, we would like to
thank the two anonymous reviewers of this paper who made several
important suggestions for improving this paper. This research was
carried out under a grant from the NASA GRACE Science Team.
NR 39
TC 26
Z9 26
U1 0
U2 4
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 2169-9275
EI 2169-9291
J9 J GEOPHYS RES-OCEANS
JI J. Geophys. Res.-Oceans
PD NOV 4
PY 2008
VL 113
IS C11
AR C11003
DI 10.1029/2008JC004930
PG 13
WC Oceanography
SC Oceanography
GA 370UD
UT WOS:000260787700001
ER
PT J
AU Wilson, CF
Guerlet, S
Irwin, PGJ
Tsang, CCC
Taylor, FW
Carlson, RW
Drossart, P
Piccioni, G
AF Wilson, C. F.
Guerlet, S.
Irwin, P. G. J.
Tsang, C. C. C.
Taylor, F. W.
Carlson, R. W.
Drossart, P.
Piccioni, G.
TI Evidence for anomalous cloud particles at the poles of Venus
SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS
LA English
DT Article
ID RADIATIVE-TRANSFER; ATMOSPHERE; GALILEO; NIGHTSIDE; MISSION; MODEL;
SIDE; NIMS
AB An analysis of near-infrared emissions on the nightside of Venus observed by the Visible and Infrared Thermal Imaging Spectrometer (VIRTIS) instrument on board Venus Express reveals anomalous cloud particles in the polar regions of Venus. These anomalous particles are found within the centers of polar vortices at both poles and are either larger or different in composition from those elsewhere in the planet. We find no persistent latitudinal variation in cloud properties at low to midlatitudes, nor do we find asymmetry between the southern and northern hemispheres. These findings arise from analysis of the relative brightness of 1.74 and 2.30 mu m infrared radiation thermally emitted from the deep atmosphere of Venus. Larger cloud particles cause relatively more attenuation at 2.30 mu m than at 1.74 mu m, so we use a "size parameter,'' m = (I(1.74)mu m)/(I(2.30)mu m) 0.53, as a proxy for particle size. This methodology follows that of Carlson et al. (1993), supported by new radiative transfer modeling.
C1 [Wilson, C. F.; Irwin, P. G. J.; Tsang, C. C. C.; Taylor, F. W.] Univ Oxford, Dept Phys, Oxford OX1 3PU, England.
[Carlson, R. W.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[Guerlet, S.; Drossart, P.] Observ Paris, Lab Etud Spatiales & Instrumentat Astrophys, F-92195 Meudon, France.
[Piccioni, G.] Ist Astrofis Spaziale & Fis Cosm, I-00133 Rome, Italy.
RP Wilson, CF (reprint author), Univ Oxford, Dept Phys, Parks Rd, Oxford OX1 3PU, England.
EM wilson@atm.ox.ac.uk
FU UK Science and Technology Facilities Council; CNES; ASI; NASA
FX We acknowledge the work of the entire Venus Express team, who allowed
these data to be obtained. This work was made possible by funding from
the UK Science and Technology Facilities Council, as well as national
space agencies CNES, ASI, and NASA.
NR 28
TC 19
Z9 19
U1 0
U2 1
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0148-0227
J9 J GEOPHYS RES-PLANET
JI J. Geophys. Res.-Planets
PD NOV 4
PY 2008
VL 113
AR E00B13
DI 10.1029/2008JE003108
PG 12
WC Geochemistry & Geophysics
SC Geochemistry & Geophysics
GA 370TW
UT WOS:000260787000001
ER
PT J
AU Li, ZR
Little, R
Dervishi, E
Saini, V
Xu, Y
Biris, AR
Lupu, D
Trigwell, S
Saini, D
Biris, AS
AF Li, Zhongrui
Little, Reginald
Dervishi, Enkeleda
Saini, Viney
Xu, Yang
Biris, Alexandru R.
Lupu, Dan
Trigwell, Steve
Saini, Divey
Biris, Alexandru S.
TI Micro-Raman spectroscopy analysis of catalyst morphology for carbon
nanotubes synthesis
SO CHEMICAL PHYSICS
LA English
DT Article
DE Carbon nanotubes; Chemical vapor deposition; Catalysts; Raman
spectroscopy
ID EXCITATION WAVELENGTH; PHASE-TRANSITIONS; HIGH-PRESSURES; CVD SYNTHESIS;
GROWTH; SPECTRA; GRAPHITE; SUPPORT; ORIGIN; BAND
AB Multiwall carbon nanotubes (CNTs) were grown using the chemical vapor deposition method by applying C2H2 fluxed over FexCo5-x/CaCO3 catalyst under radio frequency heating. Micro-Raman scattering investigations of the metal active species over the oxidic support allowed the understanding of the relationship between the compositional distribution among the catalyst particles and the nanotube production rate, diameter distribution and morphology. It was proved that the catalyst chemical and structural non-uniformities of the active metals relative ratios (FexCo5-x) strongly influence the carbon deposition rate as well as the nanotube crystallinity characteristics. The catalytic activity of the FexCo5-x alloy relative to pure metals was correlated with the better relative permeability and polarizability contributed by certain ratios of Fe and Co as active catalytic species. It was also found evidence that catalyst pretreatment plays an active role on the nanotube yield and morphology. Micro-Raman spectroscopy of the catalytic systems was used successfully to predict the quality and crystallinity of the corresponding carbon nanotubes. (C) 2008 Elsevier B.V. All rights reserved.
C1 [Li, Zhongrui; Dervishi, Enkeleda; Saini, Viney; Xu, Yang; Biris, Alexandru S.] Univ Arkansas, Dept Appl Sci, Nanotechnol Ctr, Little Rock, AR 72204 USA.
[Little, Reginald] Florida State Univ, Natl High Magnet Field Lab, Tallahassee, FL 32310 USA.
[Biris, Alexandru R.; Lupu, Dan] Natl Inst Res & Dev Isotop & Mol Technol, R-400293 Cluj Napoca, Romania.
[Trigwell, Steve] NASA, Electrostat & Surface Phys Lab, Kennedy Space Ctr, Kennedy Space Ctr, FL 32899 USA.
[Saini, Divey] St Louis Univ, Hlth Sci Ctr, Dept Mol Microbiol & Immunol, St Louis, MO 63104 USA.
RP Li, ZR (reprint author), Univ Arkansas, Dept Appl Sci, Nanotechnol Ctr, Little Rock, AR 72204 USA.
EM zxli3@ualr.edu; asbiris@ualr.edu
RI Biris, Alexandru/A-8507-2010; Lupu, Dan/C-3346-2009; Dervishi,
Enkeleda/B-2239-2010; Biris, Alexandru /C-4517-2011
FU US Department of Energy [DE-FG 36-06 GO 86072]; Arkansas Science and
Technology Authority (ASTA) [08-CAT-03]
FX This work was partially funded by a grant provided by the US Department
of Energy (Grant No. DE-FG 36-06 GO 86072). Also the financial support
from Arkansas Science and Technology Authority (ASTA) Grant # 08-CAT-03
is highly appreciated.
NR 45
TC 9
Z9 9
U1 2
U2 8
PU ELSEVIER SCIENCE BV
PI AMSTERDAM
PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS
SN 0301-0104
EI 1873-4421
J9 CHEM PHYS
JI Chem. Phys.
PD NOV 3
PY 2008
VL 353
IS 1-3
BP 25
EP 31
DI 10.1016/j.chemphys.2008.07.013
PG 7
WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical
SC Chemistry; Physics
GA 375SX
UT WOS:000261134700004
ER
PT J
AU Her, JH
Yousufuddin, M
Zhou, W
Jalisatgi, SS
Kulleck, JG
Zan, JA
Hwang, SJ
Bowman, RC
Udovic, TJ
AF Her, Jae-Hyuk
Yousufuddin, Muhammed
Zhou, Wei
Jalisatgi, Satish S.
Kulleck, James G.
Zan, Jason A.
Hwang, Son-Jong
Bowman, Robert C., Jr.
Udovic, Terrence J.
TI Crystal Structure of Li2B12H12: a Possible Intermediate Species in the
Decomposition of LiBH4
SO INORGANIC CHEMISTRY
LA English
DT Article
ID NEUTRON-SCATTERING
AB The crystal structure of solvent-free Li2B12H12 has been determined by powder X-ray diffraction and confirmed by a combination of neutron vibrational spectroscopy and first-principles calculations. This compound is a possible intermediate in the dehydrogenation of LiBH4, and its structural characterization is crucial for understanding the decomposition and regeneration of LiBH4. Our results reveal that the structure of Li2B12H12 differs from other known alkali-metal (K, Rb, and Cs) derivatives.
C1 [Her, Jae-Hyuk; Yousufuddin, Muhammed; Zhou, Wei; Udovic, Terrence J.] NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA.
[Her, Jae-Hyuk; Yousufuddin, Muhammed; Zhou, Wei] Univ Maryland, Dept Mat Sci & Engn, College Pk, MD 20742 USA.
[Jalisatgi, Satish S.] Univ Missouri, Dept Radiol, Int Inst Nano & Mol Med, Columbia, MO 65211 USA.
[Kulleck, James G.; Zan, Jason A.; Bowman, Robert C., Jr.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[Hwang, Son-Jong] CALTECH, Div Chem & Chem Engn, Pasadena, CA 91125 USA.
RP Her, JH (reprint author), NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA.
EM jhher@nist.gov
RI Zhou, Wei/C-6504-2008;
OI Zhou, Wei/0000-0002-5461-3617; Bowman, Robert/0000-0002-2114-1713
NR 13
TC 88
Z9 88
U1 3
U2 26
PU AMER CHEMICAL SOC
PI WASHINGTON
PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA
SN 0020-1669
J9 INORG CHEM
JI Inorg. Chem.
PD NOV 3
PY 2008
VL 47
IS 21
BP 9757
EP 9759
DI 10.1021/ic801345h
PG 3
WC Chemistry, Inorganic & Nuclear
SC Chemistry
GA 365RY
UT WOS:000260426700012
PM 18834192
ER
PT J
AU Huang, Y
Chameides, WL
Tan, Q
Dickinson, RE
AF Huang, Yan
Chameides, William L.
Tan, Qian
Dickinson, Robert E.
TI Characteristics of Anthropogenic Sulfate and Carbonaceous Aerosols over
East Asia: Regional Modeling and Observation
SO ADVANCES IN ATMOSPHERIC SCIENCES
LA English
DT Article; Proceedings Paper
CT ESSP Open Science Conference on Global Change
CY NOV 09-11, 2006
CL Beijing, PEOPLES R CHINA
DE regional climate modeling; anthropogenic emission; sulfate aerosol;
black carbon and organic carbon; East Asia
ID GLOBAL 3-DIMENSIONAL MODEL; TROPOSPHERIC SULFUR CYCLE;
GENERAL-CIRCULATION MODEL; YANGTZE DELTA REGION; UNITED-STATES;
PARTICULATE MATTER; HYDROLOGICAL CYCLE; RADIATIVE-TRANSFER; DRY
DEPOSITION; CROP YIELDS
AB The authors present spatial and temporal characteristics of anthropogenic sulfate and carbonaceous aerosols over East Asia using a 3-D coupled regional climate-chemistry-aerosol model, and compare the Simulation with the limited aerosol observations over the region. The aerosol. module consists of SO2 SO4-2, hydrophobic and hydrophilic black carbon (BC) and organic carbon compounds (OC) including emission, advections, dry and wet deposition, and chemical production and conversion. The simulated patterns of SO2 are closely tied to its emission rate, with sharp gradients between the highly polluted regions and more rural areas. Chemical conversion (especially in the aqueous phase) and dry deposition remove 60% and 30% of the total SO2 emission, respectively. The SO4-2 shows less horizontal gradient and seasonality than SO2, with wet deposition (60%) and export (27%) being two major sinks. Carbonaceous aerosols are spatially smoother than Sulfur species. The aging process transforms more than 80% of hydrophobic BC and OC to hydrophilic components, which are removed by wet deposition (60%) and export, (30%). The simulated spatial and seasonal SO4-2, BC and OC aerosol concentrations and total aerosol optical depth are generally consistent with the observations in rural areas over East Asia, with lower bias in simulated OC aerosols, likely due to the underestimation of anthropogenic OC emissions and missing treatment of secondary organic carbon. The results suggest that our model is a useful tool for characterizing the anthropogenic aerosol cycle and for assessing its potential climatic and environmental effects in future studies.
C1 [Huang, Yan; Dickinson, Robert E.] Georgia Inst Technol, Sch Earth & Atmospher Sci, Atlanta, GA 30332 USA.
[Chameides, William L.] Duke Univ, Nicholas Sch Environm & Earth Sci, Durham, NC 27708 USA.
[Tan, Qian] Univ Maryland, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21228 USA.
RP Huang, Y (reprint author), Georgia Inst Technol, Sch Earth & Atmospher Sci, Atlanta, GA 30332 USA.
EM yhuang@eas-gatech.edu
RI AAS, AAS/C-2949-2014
NR 57
TC 6
Z9 7
U1 1
U2 2
PU SCIENCE PRESS
PI BEIJING
PA 16 DONGHUANGCHENGGEN NORTH ST, BEIJING 100717, PEOPLES R CHINA
SN 0256-1530
EI 1861-9533
J9 ADV ATMOS SCI
JI Adv. Atmos. Sci.
PD NOV
PY 2008
VL 25
IS 6
BP 946
EP 959
DI 10.1007/s00376-008-0946-z
PG 14
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 374NX
UT WOS:000261052100005
ER
PT J
AU Reichle, RH
AF Reichle, Rolf H.
TI Data assimilation methods in the Earth sciences
SO ADVANCES IN WATER RESOURCES
LA English
DT Article
DE Data assimilation; Remote sensing; Land surface hydrology; Variational
methods; Kalman filter
ID ENSEMBLE KALMAN FILTER; HYDROLOGIC DATA ASSIMILATION; ATMOSPHERIC DATA
ASSIMILATION; SURFACE DATA ASSIMILATION; SOIL-MOISTURE; BIAS CORRECTION;
TEMPERATURE; PARAMETERS; MODEL
AB Although remote sensing data are often plentiful, they do not usually satisfy the users' needs directly. Data assimilation is required to extract information about geophysical fields of interest from the remote sensing observations and to make the data more accessible to users. Remote sensing may provide, for example, measurements of surface soil moisture, snow water equivalent, snow cover, or land surface (skin) temperature. Data assimilation can then be used to estimate variables that are not directly observed from space but are needed for applications, for instance root zone soil moisture or land surface fluxes. The paper provides a brief introduction to modern data assimilation methods in the Earth sciences, their applications, and pertinent research questions. Our general overview is readily accessible to hydrologic remote sensing scientists. Within the general context of Earth science data assimilation, we point to examples of the assimilation of remotely sensed observations in land surface hydrology. (C) 2008 Elsevier Ltd. All rights reserved.
C1 [Reichle, Rolf H.] NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Greenbelt, MD 20771 USA.
[Reichle, Rolf H.] Univ Maryland, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21201 USA.
RP Reichle, RH (reprint author), NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Code 610-1, Greenbelt, MD 20771 USA.
EM rolf.reichle@nasa.gov
RI Reichle, Rolf/E-1419-2012
NR 54
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U1 6
U2 44
PU ELSEVIER SCI LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND
SN 0309-1708
J9 ADV WATER RESOUR
JI Adv. Water Resour.
PD NOV
PY 2008
VL 31
IS 11
SI SI
BP 1411
EP 1418
DI 10.1016/j.advwatres.2008.01.001
PG 8
WC Water Resources
SC Water Resources
GA 383BR
UT WOS:000261649600001
ER
PT J
AU Kumar, SV
Reichle, RH
Peters-Lidard, CD
Koster, RD
Zhan, XW
Crow, WT
Eylander, JB
Houser, PR
AF Kumar, Sujay V.
Reichle, Rolf H.
Peters-Lidard, Christa D.
Koster, Randal D.
Zhan, Xiwu
Crow, Wade T.
Eylander, John B.
Houser, Paul R.
TI A land surface data assimilation framework using the land information
system: Description and applications
SO ADVANCES IN WATER RESOURCES
LA English
DT Article
DE Land surface modeling; Data assimilation; Remote sensing; Hydrology;
Soil moisture; Snow
ID ENSEMBLE KALMAN FILTER; CATCHMENT-BASED APPROACH; SOIL-MOISTURE;
SNOW-COVER; MODEL; UNCERTAINTY; IMPACT; BIAS
AB The Land Information System (LIS) is an established land surface modeling framework that integrates various community land surface models, ground measurements, satellite-based observations, high performance computing and data management tools. The use of advanced software engineering principles in LIS allows interoperability of individual system components and thus enables assessment and prediction of hydrologic conditions at various spatial and temporal scales. In this work, we describe a sequential data assimilation extension of LIS that incorporates multiple observational sources, land surface models and assimilation algorithms. These capabilities are demonstrated here in a suite of experiments that use the ensemble Kalman filter (EnKF) and assimilation through direct insertion. In a soil moisture experiment, we discuss the impact of differences in modeling approaches on assimilation performance. Provided careful choice of model error parameters, we find that two entirely different hydrological modeling approaches offer comparable assimilation results. In a snow assimilation experiment, we investigate the relative merits of assimilating different types of observations (snow cover area and snow water equivalent). The experiments show that data assimilation enhancements in LIS are uniquely suited to compare the assimilation of various data types into different land surface models within a single framework. The high performance infrastructure provides adequate support for efficient data assimilation integrations of high computational granularity. (C) 2008 Elsevier Ltd. All rights reserved.
C1 [Kumar, Sujay V.; Reichle, Rolf H.] Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21250 USA.
[Kumar, Sujay V.; Peters-Lidard, Christa D.] NASA, Goddard Space Flight Ctr, Hydrol Sci Branch, Greenbelt, MD 20771 USA.
[Reichle, Rolf H.; Koster, Randal D.] NASA, Goddard Space Flight Ctr, NASA Global Modeling & Assimilat Off, Greenbelt, MD 20771 USA.
[Zhan, Xiwu] NOAA, NESDIS, Ctr Satellite Applicat & Res, Camp Springs, MD 20746 USA.
[Crow, Wade T.] ARS, USDA, Hydrol & Remote Sensing Lab, Beltsville, MD 20705 USA.
[Houser, Paul R.] George Mason Univ, Ctr Res Environm & Water, Beltsville, MD 20705 USA.
RP Kumar, SV (reprint author), Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21250 USA.
EM Sujay.V.Kumar@nasa.gov
RI Zhan, Xiwu/F-5487-2010; Reichle, Rolf/E-1419-2012; Koster,
Randal/F-5881-2012; Houser, Paul/J-9515-2013; Kumar, Sujay/B-8142-2015;
Peters-Lidard, Christa/E-1429-2012
OI Koster, Randal/0000-0001-6418-6383; Houser, Paul/0000-0002-2991-0441;
Peters-Lidard, Christa/0000-0003-1255-2876
FU NASA Goddard Space Flight Center; NASA Energy and Water Cycle (NEWS)
program; NASA Earth Observing System (EOS) program; Joint Center for
Satellite Data Assimilation (JCSDA)
FX We gratefully acknowledge support of LIS data assimilation development
by the Air Force Weather Agency, internal investment from NASA Goddard
Space Flight Center, the NASA Energy and Water Cycle (NEWS) program, the
NASA Earth Observing System (EOS) program, and a grant from the Joint
Center for Satellite Data Assimilation (JCSDA), among others. We also
thank Dr. Sarith Mahanama and James V. Geiger for their help in the
implementation of Catchment land surface model in LIS and Dr. Jiarui
Dong for helpful discussions.
NR 44
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PU ELSEVIER SCI LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND
SN 0309-1708
EI 1872-9657
J9 ADV WATER RESOUR
JI Adv. Water Resour.
PD NOV
PY 2008
VL 31
IS 11
SI SI
BP 1419
EP 1432
DI 10.1016/j.advwatres.2008.01.013
PG 14
WC Water Resources
SC Water Resources
GA 383BR
UT WOS:000261649600002
ER
PT J
AU Merlin, O
Walker, JP
Kalma, JD
Kim, EJ
Hacker, J
Panciera, R
Young, R
Summerell, G
Hornbuckle, J
Hafeez, M
Jackson, T
AF Merlin, Olivier
Walker, Jeffrey P.
Kalma, Jetse D.
Kim, Edward J.
Hacker, Jorg
Panciera, Rocco
Young, Rodger
Summerell, Gregory
Hornbuckle, John
Hafeez, Mohsin
Jackson, Thomas
TI The NAFE'06 data set: Towards soil moisture retrieval at intermediate
resolution
SO ADVANCES IN WATER RESOURCES
LA English
DT Article
DE Soil moisture; Airborne experiment; L-band radiometry; Multi-spectral;
Synergy; Calibration/validation; Downscaling; Assimilation
ID WATER-CONTENT; SPACE; ASSIMILATION; CALIBRATION; MONSOON-90; EMISSION;
GRASS
AB The National Airborne Field Experiment 2006 (NAFE'06) was conducted during a three week period of November 2006 in the Murrumbidgee River catchment, located in southeastern Australia. One objective of NAFE'06 was to explore the suitability of the area for SMOS (Soil Moisture and Ocean Salinity) calibration/validation and develop downscaling and assimilation techniques for when SMOS does come on line. Airborne L-band brightness temperature was mapped at 1 km resolution 11 times (every 1-3 days) over a 40 by 55 km area in the Yanco region and 3 times over a 40 by 50 km area that includes Kyeamba Creek catchment. Moreover, multi-resolution, multi-angle and multi-spectral airborne data including surface temperature, surface reflectance (green, read and near infrared), lidar data and aerial photos were acquired over selected areas to develop downscaling algorithms and test multi-angle and multi-spectral retrieval approaches. The near-surface soil moisture was measured extensively on the ground in eight sampling areas concurrently with aircraft flights, and the soil moisture profile was continuously monitored at 41 sites. Preliminary analyses indicate that (i) the uncertainty of a single ground measurement was typically less than 5% vol. (ii) the spatial variability of ground measurements at I km resolution was up to 10% vol. and (iii) the validation of I kin resolution L-band data is facilitated by selecting pixels with a spatial soil moisture variability lower than the point-scale uncertainty. The sensitivity of passive microwave and thermal data is also compared at I kin resolution to illustrate the multi-spectral synergy for soil moisture monitoring at improved accuracy and resolution. The data described in this paper are available at www.nafe.unimelb.edu.au. (C) 2008 Elsevier Ltd. All rights reserved.
C1 [Merlin, Olivier; Walker, Jeffrey P.; Panciera, Rocco; Young, Rodger] Univ Melbourne, Melbourne, Vic 3010, Australia.
[Kalma, Jetse D.] Univ Newcastle, Sch Engn, Callaghan, NSW 2308, Australia.
[Kim, Edward J.] NASA, Goddard Space Flight Ctr, Greenbelt, MD USA.
[Hacker, Jorg] Flinders Univ Airborne, Res Australia, Adelaide, SA, Australia.
[Jackson, Thomas] USDA, Washington, DC USA.
RP Merlin, O (reprint author), Univ Melbourne, Melbourne, Vic 3010, Australia.
EM omerlin@unimelb.edu.au
RI Hornbuckle, John/D-5981-2011; Walker, Jeffrey/D-2624-2009
FU Australian Research Council [LE0453434, LE0560930, DP0557543,
DP0343778]; collaboration of a large number of scientists from
throughout Australia, United States and Europe; CRC for Catchment
Hydrology
FX The Yanco farmers involved in the field experiment, Wayne Durnan, David
Gooden, Adrian Hays, Franck McKersie, Murray Shaw, and Danean Smith, are
gratefully acknowledged. Likewise the landholders of the Livingstone
Creek and Yenda site are acknowledged for access to their properties.
Coleambally Irrigation Co-operative Limited is also acknowledged for
their logistical support in the preparation of the ground sampling. We
wish to thank the NAFE'06 participants, Elizabeth Botha, Gilles Boulet,
Micah Bell, Aaron Berg, Shakti Chakravarty, Yuriming Chen, Evan
Christen, Richard de Jeu, Clara Draper, Carmen Gomez, Dionne Hansen,
Ruud Hurkmans, Jon Johanson, Vadim Kuzmin, Venkat Lakshmi, Philippe
Maisongrande, Lynn McKee, Iva Mladenova, Peggy O'Neill, Walter Rawls,
Victor Shoemark, Ryan Teuling, Mark Thyer, and Jessika Toyra. The
National Airborne Field Experiments have been made possible through
recent infrastructure (LE0453434 and LE0560930) and research (DP0557543)
funding from the Australian Research Council, and the collaboration of a
large number of scientists from throughout Australia, United States and
Europe. Initial setup and maintenance of the study catchments was funded
by a research grant (DP0343778) from the Australian Research Council and
by the CRC for Catchment Hydrology.
NR 29
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PU ELSEVIER SCI LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND
SN 0309-1708
J9 ADV WATER RESOUR
JI Adv. Water Resour.
PD NOV
PY 2008
VL 31
IS 11
BP 1444
EP 1455
DI 10.1016/j.advwatres.2008.01.018
PG 12
WC Water Resources
SC Water Resources
GA 383BR
UT WOS:000261649600004
ER
PT J
AU Molotch, NP
Margulis, SA
AF Molotch, Noah P.
Margulis, Steven A.
TI Estimating the distribution of snow water equivalent using remotely
sensed snow cover data and a spatially distributed snowmelt model: A
multi-resolution, multi-sensor comparison
SO ADVANCES IN WATER RESOURCES
LA English
DT Article
DE Snow & ice; Snowmelt; Modeling; Remote sensing; Snow water equivalent;
Rio grande
ID LANDSAT THEMATIC MAPPER; MOUNTAIN BASINS; SPECTRAL ALBEDO; RUNOFF MODEL;
SURFACE; MODIS; ENERGY; RADIATION; ASSIMILATION; REFLECTANCE
AB Time series of fractional snow covered area (SCA) estimates from Landsat Enhanced Thematic Mapper (ETM+), Moderate Resolution Imaging Spectroradiometer (MODIS), and Advanced Very High Resolution Radiometer (AVHRR) data were combined with a spatially distributed snowmelt model to reconstruct snow water equivalent (SWE) in the Rio Grande headwaters (3419 km(2)). In this reconstruction approach, modeled snowmelt over each pixel is integrated during the period of satellite-observed snow cover to estimate SWE. Due to underestimates in snow cover detection, maximum basin-wide mean SWE using MODIS and AVHRR were, respectively, 45% and 68% lower than SWE estimates obtained using ETM+ data. The mean absolute error (MAE) of SWE estimated at 100-m resolution using ETM+ data was 23% relative to observed SWE from intensive field campaigns. Model performance deteriorated when MODIS (MAE - 50%) and AVHRR (MAE = 89%) SCA data were used. Relative to differences in the SCA products, model output was less sensitive to spatial resolution (MAE = 39% and 73% for ETM+ and MODIS simulations run at 1 km resolution, respectively), indicating that SWE reconstructions at the scale of MODIS acquisitions may be tractable provided the SCA product is improved. When considering tradeoffs between spatial and temporal resolution of different sensors, our results indicate that higher spatial resolution products such as ETM+ remain more accurate despite the lower frequency of acquisition. This motivates continued efforts to improve MODIS snow cover products. (C) 2008 Elsevier Ltd. All rights reserved.
C1 [Molotch, Noah P.; Margulis, Steven A.] Univ Calif Los Angeles, Dept Civil & Environm Engn, Los Angeles, CA 90095 USA.
[Molotch, Noah P.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Molotch, NP (reprint author), Univ Calif Los Angeles, Dept Civil & Environm Engn, 5732 Boelter Hall, Los Angeles, CA 90095 USA.
EM molotch@seas.ucla.edu
RI Molotch, Noah/C-8576-2009
FU National Science Foundation Hydrologic Sciences [EAR-0711600]; National
Oceanic and Atmospheric Administration Office of Hydrologic Development
[NA07NWS4620016]; Cooperative Institute for Research in Environmental
Sciences; University of Colorado, Boulder and NASA [NNG04GO74G,
NNX08AH18G]; Sustainability of Hydrology and Riparian Areas (SAHRA)
FX This research was supported by the National Science Foundation
Hydrologic Sciences (EAR-0711600) and by the National Oceanic and
Atmospheric Administration Office of Hydrologic Development
(NA07NWS4620016). Additional support was provided by a research
fellowship at the Cooperative Institute for Research in Environmental
Sciences, University of Colorado, Boulder and NASA Grants #NNG04GO74G,
NNX08AH18G. Data collection was supported by the National Science
Foundation, Science and Technology Center for the Sustainability of
Hydrology and Riparian Areas (SAHRA). Walter Rosenthal is acknowledged
for processing the Landsat snow cover data. R. Bales, T. Bardsley, R.
Brice, R. Davis, J. Dozier, S. Fassnacht, J. McConnell, C. McKenzie, and
T. Painter contributed to technical support and useful discussions. The
Wolf Creek Ski Area, D. Pitcher, and field assistants are acknowledged
for field support.
NR 60
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U1 1
U2 33
PU ELSEVIER SCI LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND
SN 0309-1708
J9 ADV WATER RESOUR
JI Adv. Water Resour.
PD NOV
PY 2008
VL 31
IS 11
BP 1503
EP 1514
DI 10.1016/j.advwatres.2008.07.017
PG 12
WC Water Resources
SC Water Resources
GA 383BR
UT WOS:000261649600009
ER
PT J
AU Turso, JA
Litt, JS
AF Turso, J. A.
Litt, J. S.
TI Toward an intelligent, deterioration accommodating controller for aging
turbofan engines
SO AERONAUTICAL JOURNAL
LA English
DT Article
AB A method for accommodating engine deterioration via a scheduled linear parameter varying quadratic Lyapunov function (LPVQLF)-based controller is presented. The LPVQLF design methodology provides a means for developing unconditionally stable, robust control of linear parameter varying (LPV) systems. The controller is scheduled on the engine deterioration index, a function of estimated parameters that relate to engine health, and is computed using a multilayer feedforward neural network. Acceptable thrust response and tight control of exhaust gas temperature (EGT) is accomplished by adjusting the performance weighting on these parameters for different levels of engine degradation. Nonlinear Simulations demonstrate that the controller achieves specified performance objectives while being robust to engine deterioration as well as engine-to-engine variations.
C1 [Turso, J. A.] Northrop Grumman Ship Syst, Pascagoula, MS USA.
[Litt, J. S.] NASA, Glenn Res Ctr, Cleveland, OH USA.
RP Turso, JA (reprint author), Northrop Grumman Ship Syst, Pascagoula, MS USA.
NR 24
TC 1
Z9 1
U1 0
U2 1
PU ROYAL AERONAUTICAL SOC
PI LONDON
PA 4 HAMILTON PL, LONDON W1J 7BQ, ENGLAND
SN 0001-9240
J9 AERONAUT J
JI Aeronaut. J.
PD NOV
PY 2008
VL 112
IS 1137
BP 641
EP 651
PG 11
WC Engineering, Aerospace
SC Engineering
GA 382GP
UT WOS:000261594000002
ER
PT J
AU Chabalko, CC
Hajj, MR
Silva, WA
AF Chabalko, Christopher C.
Hajj, Muhammad R.
Silva, Walter A.
TI Interrogative Testing for Nonlinear Identification of Aeroelastic
Systems
SO AIAA JOURNAL
LA English
DT Editorial Material
ID SEMISPAN MODEL
C1 [Chabalko, Christopher C.; Hajj, Muhammad R.] Virginia Polytech Inst & State Univ, Blacksburg, VA 24061 USA.
[Silva, Walter A.] NASA, Langley Res Ctr, Aeroelast Branch, Hampton, VA 23681 USA.
RP Chabalko, CC (reprint author), Virginia Polytech Inst & State Univ, Blacksburg, VA 24061 USA.
RI Hajj, Muhammad/A-1176-2010
NR 4
TC 5
Z9 5
U1 0
U2 0
PU AMER INST AERONAUT ASTRONAUT
PI RESTON
PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA
SN 0001-1452
J9 AIAA J
JI AIAA J.
PD NOV
PY 2008
VL 46
IS 11
BP 2657
EP 2658
DI 10.2514/1.40092
PG 2
WC Engineering, Aerospace
SC Engineering
GA 371FT
UT WOS:000260817900001
ER
PT J
AU Kandula, M
AF Kandula, Max
TI Prediction of Turbulent Jet Mixing Noise Reduction by Water Injection
SO AIAA JOURNAL
LA English
DT Article; Proceedings Paper
CT AIAA/CEAS 13th Aeroacoustics Conference
CY MAY 21-23, 2007
CL Rome, ITALY
SP AIAA, CEAS
ID LARGE-EDDY SIMULATION; ATTENUATION; DISPERSION; SPRAYS; SOUND
AB A one-dimensional control volume formulation is developed for the determination of jet mixing noise reduction due to water injection. The analysis starts from the conservation of mass, momentum, and energy for the control volume and introduces the concept of effective jet parameters (jet temperature,jet velocity, and jet Mach number). It is shown that the water-to-jet mass How rate ratio is an important parameter characterizing the jet noise reduction on account of gas-to-droplet momentum and heat transfer. Two independent dimensionless invariant groups are postulated and provide the necessary relations for the droplet size and droplet Reynolds number. Results are presented illustrating the effect of mass flow rate ratio on the jet mixing noise reduction for a range of jet Mach numbers and jet Reynolds numbers. Predictions from the model show satisfactory comparison with available test data on perfectly expanded hot supersonic jets. The results suggest that significant noise reductions can be achieved at increased How rate ratios.
C1 [Kandula, Max] NASA, ASRC Aerosp, Kennedy Space Ctr, FL 32899 USA.
RP Kandula, M (reprint author), Mail Stop ASRC-5211, Kennedy Space Ctr, FL 32899 USA.
NR 45
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U1 0
U2 3
PU AMER INST AERONAUT ASTRONAUT
PI RESTON
PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA
SN 0001-1452
J9 AIAA J
JI AIAA J.
PD NOV
PY 2008
VL 46
IS 11
BP 2714
EP 2722
DI 10.2514/1.33599
PG 9
WC Engineering, Aerospace
SC Engineering
GA 371FT
UT WOS:000260817900006
ER
PT J
AU Leroux, H
Jacob, D
Stodolna, J
Nakamura-Messenger, K
Zolensky, ME
AF Leroux, Hugues
Jacob, Damien
Stodolna, Julien
Nakamura-Messenger, Keiko
Zolensky, Michael E.
TI Igneous Ca-rich pyroxene in comet 81P/Wild 2
SO AMERICAN MINERALOGIST
LA English
DT Article
DE Comet dust; electron microscopy; pyroxene; Stardust; phase
transformation
ID IRON-FREE CLINOPYROXENE; TRANSMISSION ELECTRON-MICROSCOPE;
X-RAY-MICROANALYSIS; FE-FREE PYROXENES; EXSOLUTION LAMELLAE; THERMAL
HISTORY; CHONDRULES; MICROSTRUCTURE; CAPTURE; OBJECTS
AB The Stardust spacecraft successfully returned dust from comet 81P/Wild 2 to Earth in January 2006. Preliminary examination of the samples showed abundant crystalline silicates comparable to those found in chondritic meteorites presumably formed in the asteroid belt. Here, we report results of a transmission electron microscopy (TEM) study of a pyroxene-bearing terminal particle, which contains lamellar intergrowths of pigeonite and diopside on the (001) plane. This microstructure is typical for an igneous process and formation by exsolution during cooling. Width and wavelength of the lamellae indicate a cooling rate within the range 10-100 degrees C/h, in close agreement with those of chondrules or lava from an asteroidal igneous rock. This observation shows that some Stardust material experienced periods of igneous processing similar to material found in the inner early solar system. This implies that igneous materials were common materials in a large region of the protoplanetary disk and were not restricted to the asteroid belt. Their presence in comet Wild 2 also supports the favored view of large radial mixing from the inner to the outer regions before the comet's accretion.
C1 [Leroux, Hugues; Jacob, Damien; Stodolna, Julien] Univ Sci & Tech Lille Flandres Artois, Lab Struct & Proprietes Etat Solide, F-59655 Villeneuve Dascq, France.
[Leroux, Hugues; Jacob, Damien; Stodolna, Julien] CNRS, UMR 8008, F-59655 Villeneuve Dascq, France.
[Nakamura-Messenger, Keiko; Zolensky, Michael E.] NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA.
RP Leroux, H (reprint author), Univ Sci & Tech Lille Flandres Artois, Lab Struct & Proprietes Etat Solide, F-59655 Villeneuve Dascq, France.
EM hugues.leroux@univ-lille1.fr
FU CNES (Centre National des Eludes Spatiales); European FEDER;
Nord-Pas-de-Calais; NASA's Stardust Data Analysis Program
FX The authors thank Jean-Francois Dhenin for his assistance with the
microscopes, M. Roskosz and S. Merkel for constructive discussions. We
are thankful for support from CNES (Centre National des Eludes
Spatiales) and from the electron microscope facility by European FEDER
and region Nord-Pas-de-Calais. M. Zolensky was supported by NASA's
Stardust Data Analysis Program. The paper has benefited from extremely
helpful and constructive reviews by H.A. Ishii and an anonymous
reviewer.
NR 34
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U1 0
U2 4
PU MINERALOGICAL SOC AMER
PI CHANTILLY
PA 3635 CONCORDE PKWY STE 500, CHANTILLY, VA 20151-1125 USA
SN 0003-004X
J9 AM MINERAL
JI Am. Miner.
PD NOV-DEC
PY 2008
VL 93
IS 11-12
BP 1933
EP 1936
DI 10.2138/am.2008.3048
PG 4
WC Geochemistry & Geophysics; Mineralogy
SC Geochemistry & Geophysics; Mineralogy
GA 374VT
UT WOS:000261072500025
ER
PT J
AU Ksendzov, A
Lewi, T
Lay, OP
Martin, SR
Gappinger, RO
Lawson, PR
Peters, RD
Shalem, S
Tsun, A
Katzir, A
AF Ksendzov, A.
Lewi, T.
Lay, O. P.
Martin, S. R.
Gappinger, R. O.
Lawson, P. R.
Peters, R. D.
Shalem, S.
Tsun, A.
Katzir, A.
TI Modal filtering for midinfrared nulling interferometry using single mode
silver halide fibers
SO APPLIED OPTICS
LA English
DT Article; Proceedings Paper
CT 1st North American Symposium, on Laser Induced Breakdown Spectroscopy
CY OCT 08-10, 2007
CL New Orleans, LA
SP Mississippi State Univ
AB We demonstrate the modal filtering properties of newly developed single mode silver halide fibers for use at midinfrared wavelengths, centered at 10.5 mu m. The goal was to achieve a suppression of nonfundamental modes greater than a factor of 300 to enable the detection and characterization of Earthlike exo-planets with a space-based nulling interferometer. Fiber segments of 4.5 cm, 10.5 cm, 15 cm, and 20 cm lengths were tested. We find that the performance of the fiber was limited not by the modal filtering properties of the core but by the unsuppressed cladding modes present at the output of the fiber. In 10.5 cm and longer sections, this effect can be alleviated by properly aperturing the output. Exclusive of coupling losses, the fiber segments of 10.5-20 cm length can provide power suppression of undesirable components of the input field by a factor of 15000 at least. The demonstrated performance thus far surpasses our requirements, such that even very short sections of fiber provide adequate modal filtering for exoplanet characterization.
C1 [Ksendzov, A.; Lay, O. P.; Martin, S. R.; Gappinger, R. O.; Lawson, P. R.; Peters, R. D.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[Lewi, T.; Shalem, S.; Tsun, A.; Katzir, A.] Tel Aviv Univ, Sch Phys & Astron, Sackler Fac Exact Sci, IL-69978 Tel Aviv, Israel.
RP Ksendzov, A (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM alexander.ksendzov@jpl.nasa.gov
NR 16
TC 19
Z9 19
U1 0
U2 1
PU OPTICAL SOC AMER
PI WASHINGTON
PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA
SN 1559-128X
EI 2155-3165
J9 APPL OPTICS
JI Appl. Optics
PD NOV 1
PY 2008
VL 47
IS 31
BP 5728
EP 5735
DI 10.1364/AO.47.005728
PG 8
WC Optics
SC Optics
GA 374AD
UT WOS:000261013700023
PM 19122712
ER
PT J
AU Lynch, DK
Woodward, CE
Gehrz, R
Helton, LA
Rudy, RJ
Russell, RW
Pearson, R
Venturini, CC
Mazuk, S
Rayner, J
Ness, JU
Starrfield, S
Wagner, RM
Osborne, JP
Page, K
Puetter, RC
Perry, RB
Schwarz, G
Vanlandingham, K
Black, J
Bode, M
Evans, A
Geballe, T
Greenhouse, M
Hauschildt, P
Krautter, J
Liller, W
Lyke, J
Truran, J
Kerr, T
Eyres, SPS
Shore, SN
AF Lynch, David K.
Woodward, Charles E.
Gehrz, Robert
Helton, L. Andrew
Rudy, Richard J.
Russell, Ray W.
Pearson, Richard
Venturini, Catherine C.
Mazuk, S.
Rayner, John
Ness, Jan-Uwe
Starrfield, Sumner
Wagner, R. Mark
Osborne, Julian P.
Page, Kim
Puetter, Richard C.
Perry, R. Brad
Schwarz, Greg
Vanlandingham, Karen
Black, John
Bode, Michael
Evans, Aneurin
Geballe, Thomas
Greenhouse, Matthew
Hauschildt, Peter
Krautter, Joachim
Liller, William
Lyke, James
Truran, Jim
Kerr, T.
Eyres, S. P. S.
Shore, Steven N.
TI NOVA V2362 CYGNI (NOVA CYGNI 2006): SPITZER, SWIFT, AND GROUND-BASED
SPECTRAL EVOLUTION
SO ASTRONOMICAL JOURNAL
LA English
DT Article
DE accretion, accretion disks; line: profiles; novae, cataclysmic
variables; stars: winds, outflows
ID POLYCYCLIC AROMATIC-HYDROCARBONS; DUST FORMATION; EMISSION;
SPECTROSCOPY; SPECTROGRAPH; TELESCOPE; MODELS; PERIOD; STARS; SPEX
AB Nova V2362 Cygni has undergone a number of very unusual changes. Ground-based spectroscopy initially revealed a normal sequence of events: the object faded and its near-infrared emission lines gradually shifted to higher excitation conditions until about day 100 when the optical fading reversed and the object slowly brightened. This was accompanied by a rise in the Swift X-ray telescope flux and a sudden shift in excitation of the visible and IR spectrum back to low levels. The new lower excitation spectrum revealed broad line widths and many P-Cygni profiles, all indicative of the ejection of a second shell. Eventually, dust formed, the X-ray brightness apparently unaffected by dust formation-peaked and then declined, and the object faded at all wavelengths. The Spitzer dust spectra revealed a number of solid-state emission features that, at this time, are not identified.
C1 [Lynch, David K.; Rudy, Richard J.; Russell, Ray W.; Pearson, Richard; Venturini, Catherine C.; Mazuk, S.] Aerosp Corp, Los Angeles, CA 90009 USA.
[Woodward, Charles E.; Gehrz, Robert; Helton, L. Andrew] Univ Minnesota, Sch Phys & Astron, Dept Astron, Minneapolis, MN 55455 USA.
[Rayner, John] Univ Hawaii, Inst Astron, Honolulu, HI 96822 USA.
[Ness, Jan-Uwe; Starrfield, Sumner] Arizona State Univ, Sch Earth & Space Explorat, Tempe, AZ 85287 USA.
[Wagner, R. Mark] Large Binocular Telescope Observ, Tucson, AZ 85721 USA.
[Osborne, Julian P.; Page, Kim] Univ Leicester, Dept Astron, Leicester LE1 7RH, Leics, England.
[Puetter, Richard C.] Univ Calif San Diego, CASS, La Jolla, CA 92093 USA.
[Perry, R. Brad] NASA Lark, Hampton, VA 23681 USA.
[Schwarz, Greg; Vanlandingham, Karen] W Chester Univ, W Chester, PA 19383 USA.
[Black, John] Chalmers, Onsala Space Observ, S-43992 Onsala, Sweden.
[Bode, Michael] Liverpool John Moores Univ, Astrophys Res Inst, Birkenhead CH41 1LD, Merseyside, England.
[Evans, Aneurin] Univ Keele, Astrophys Grp, Keele ST5 5BG, Staffs, England.
[Geballe, Thomas] Gemini Observ, Hilo, HI 96720 USA.
[Greenhouse, Matthew] NASA Goddard JWST, Greenbelt, MD 20771 USA.
[Hauschildt, Peter] Univ Hamburg, Hamburger Sternwarte, Hamburg, Germany.
[Krautter, Joachim] Landessternwarte Konigstuhl, D-69117 Heidelberg, Germany.
[Liller, William] Univ Chile, Renaca Bajo, Chile.
[Lyke, James] Keck Observ, Kamuela, HI 96743 USA.
[Truran, Jim] Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA.
[Kerr, T.] Joint Astron Ctr, Hilo, HI 96720 USA.
[Eyres, S. P. S.] Univ Cent Lancashire, Ctr Astrophys, Preston PR1 2HE, Lancs, England.
[Shore, Steven N.] Univ Pisa, Dipartimento Fis Enrico Fermi, I-56100 Pisa, Italy.
[Shore, Steven N.] Ist Nazl Fis Nucl, Sez Pisa, Pisa, Italy.
RP Lynch, DK (reprint author), Aerosp Corp, M2-266,POB 92957, Los Angeles, CA 90009 USA.
EM david.k.lynch@aero.org; chelsea@astro.umn.edu; gehrz@astro.umn.edu;
ahelton@astro.umn.edu; Richard.J.Rudy@aero.org; Ray.Russell@aero.org;
Richard.Person@aero.org; Catherine.C.Venturini@aero.org;
S.Mazuk@aero.org; rayner@ifa.hawaii.edu; sumner.starrfield@asu.edu;
ness@susie.la.asu.edu; rmw@as.arizona.edu; julo@star.le.ac.uk;
kpa@star.le.ac.uk; rpuetter@ucsd.edu; Raleigh.B.Perry@NASA.gov;
gschwarz@pha.jhu.edu; kvanlandingham@wcupa.edu; jblack@oso.chalmers.se;
mfb@astro.livjm.ac.uk; ae@astro.keele.ac.uk; tgeballe@gemini.edu;
matt.greenhouse@nasa.gov; yeti@hs.uni-hamburg.de;
j.krautter@lsw.uni-heidelberg.de; wliller@compuserve.com;
jlyke@keck.hawaii.edu; truran@nova.uchicago.edu; t.kerr@jach.hawaii.edu;
spseyres@uclan.ac.uk; shore@df.unipi.it
OI Schwarz, Gregory/0000-0002-0786-7307
FU The Aerospace Corporation's Independent Research and Development
program; Spitzer Space Telescope; Jet Propulsion Laboratory, California
Institute of Technology (CalTech); NASA; NSF; Chandra Postdoctoral
Fellowship [PF5-60039]; The Chandra X-Ray Center; Smithsonian
Astrophysical Observatory for NASA [NAS8-03060]
FX This work was supported in part by The Aerospace Corporation's
Independent Research and Development program. We thank Daryl Kim, Ralph
Ford, and Trishana Prater of the Aerospace Corporation for assistance in
obtaining and reducing the IRTF data. We also thank IRTF telescope
operators David Griep, William Golisch, and Paul Sears, as well as Lick
telescope operators Kris Miller and Keith Baker. This work is based (in
part) on observations made with the Spitzer Space Telescope, which is
operated by the Jet Propulsion Laboratory, California Institute of
Technology (CalTech) under a contract with NASA. Support for this work
was provided by NASA through an award issued by JPL/Caltech. We
acknowledge with thanks the variable star observations from the AAVSO
International Database contributed by observers worldwide and used in
this research. J.P.O. and K. P. acknowledge support from the Science and
Technology Facilities Council (STFC) and are grateful to the SWIFT PI
Prof. Neil Gehrel for his support of this observation campaign. We also
thank David Dearborn for informative discussions about TNRs and Angela
Speck for useful discussions about dust emission. Sumner Starrfield
acknowledges NSF and NASA grants to Arizona State University. J.-U.N.
gratefully acknowledges support provided by NASA through Chandra
Postdoctoral Fellowship grant PF5-60039 awarded by The Chandra X-Ray
Center, which is operated by the Smithsonian Astrophysical Observatory
for NASA under contract NAS8-03060.
NR 31
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PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND
SN 0004-6256
J9 ASTRON J
JI Astron. J.
PD NOV
PY 2008
VL 136
IS 5
BP 1815
EP 1827
DI 10.1088/0004-6256/136/5/1815
PG 13
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 361MT
UT WOS:000260132500006
ER
PT J
AU Krist, JE
Stapelfeldt, KR
Hester, JJ
Healy, K
Dwyer, SJ
Gardner, CL
AF Krist, John E.
Stapelfeldt, Karl R.
Hester, J. Jeff
Healy, Kevin
Dwyer, Steven J.
Gardner, Carl L.
TI A MULTI-EPOCH HST STUDY OF THE HERBIG-HARO FLOW FROM XZ TAURI
SO ASTRONOMICAL JOURNAL
LA English
DT Article
DE binaries: general; ISM: Herbig; Haro objects; stars: individual (XZ
Tau); stars: pre-main sequence
ID HUBBLE-SPACE-TELESCOPE; HL TAURI; BOW SHOCK; STARS; EVOLUTION; EMISSION;
REGION; IMAGES; L1551; DISK
AB We present nine epochs of Hubble Space Telescope optical imaging of the bipolar outflow from the pre-main-sequence binary XZ Tauri. Our data monitor the system from 1995 to 2005 and include emission line images of the flow. The northern lobe appears to be a succession of bubbles, the outermost of which expanded ballistically from 1995 to 1999 but in 2000 began to deform and decelerate along its forward edge. It reached an extent of 6 '' from the binary in 2005. A larger and fainter southern counterbubble was detected for the first time in deep Advanced Camera for Surveys images from 2004. Traces of shocked emission are seen as far as 20 '' south of the binary. The bubble emission nebulosity has a low excitation overall, as traced by the [S II]/H alpha line ratio, requiring a nearly comoving surrounding medium that has been accelerated by previous ejections or stellar winds. Within the broad bubbles there are compact emission knots whose alignments and proper motions indicate that collimated jets are ejected from each binary component. The jet from the southern component, XZ Tau A, is aligned with the outflow axis of the bubbles and has tangential knot velocities of 70-200 km s(-1). Knots in the northern flow are seen to slow and brighten as they approach the forward edge of the outermost bubble. The knots in the jet from the other star, XZ Tau B, have lower velocities of similar to 100 km s(-1). To explain the observations of the outer bubble, we propose that the XZ Tau A stellar jet underwent a large velocity pulse circa 1980. This ejection quickly overtook older, slower-moving ejecta very near the star, producing a similar to 70 km s(-1) shock in a hot (T similar to 80,000 K), compact "fireball." The initial thermal pressure of this gas parcel drove the expansion of a spherical bubble. Subsequent cooling caused the bubble to transition to ballistic expansion, followed by slowing of its forward edge by mass loading from the pre-shock medium. Repeated pulses may explain the multiple bubbles seen in the data. Collimated jets continue to flow through the bubble's interior, and with the fading of the original fireball they are becoming the primary energizing mechanism for the emission line structures. Future evolution of the flow should see the outer bubble structures fade from view, and the emergence of a more typical Herbig-Haro jet/bow shock morphology. We present a preliminary numerical model of a pulsed jet to illustrate this scenario.
C1 [Krist, John E.; Stapelfeldt, Karl R.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[Hester, J. Jeff; Healy, Kevin] Arizona State Univ, Sch Earth & Space Explorat, Tempe, AZ 85287 USA.
[Gardner, Carl L.] Arizona State Univ, Dept Math & Stat, Tempe, AZ 85287 USA.
RP Krist, JE (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
RI Stapelfeldt, Karl/D-2721-2012
FU Space Telescope Science Institute; HST GO [6754, 8289, 8771, 9236,
9863]; STScI, Arizona State University; Jet Propulsion Laboratory;
California Institute of Technology
FX This research has made use of the HST, operated by the Space Telescope
Science Institute under a contract with NASA. This research was
supported by HST GO grants 6754, 8289, 8771, 9236, and 9863 to STScI,
Arizona State University, and to the Jet Propulsion Laboratory,
California Institute of Technology. We thank Angela Cotera for allowing
us the use of her ACS polarimetric images for this study and Andrew
Williams for assembling the animated version of Figure 12.
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PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND
SN 0004-6256
J9 ASTRON J
JI Astron. J.
PD NOV
PY 2008
VL 136
IS 5
BP 1980
EP 1994
DI 10.1088/0004-6256/136/5/1980
PG 15
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 361MT
UT WOS:000260132500022
ER
PT J
AU Herbig, GH
Vacca, WD
AF Herbig, G. H.
Vacca, William D.
TI THE UNUSUAL OBJECT IC 2144/MWC 778
SO ASTRONOMICAL JOURNAL
LA English
DT Article
DE reflection nebulae; stars: emission-line; stars: individual (MWC 778);
stars: pre-main sequence
ID NEAR-INFRARED SPECTRA; EMISSION-LINE; PLANETARY-NEBULAE; IRAS SOURCES;
YOUNG STARS; FE-II; RECOMBINATION; LKH-ALPHA-101; SPECTROGRAPH;
EXTINCTION
AB IC 2144 is a small reflection nebula located in the zone of avoidance near the Galactic anticenter. It has been investigated here largely on the basis of Keck/HIRES optical spectroscopy (R approximate to 48,000) and a SpeX spectrogram of the near-IR (NIR; R = 2000) obtained at the NASA Infrared Telescope Facility. The only star in the nebula that is obvious in the optical or NIR is the peculiar emission-line object MWC 778 (V = 12.8), which resembles a T Tauri star in some respects. What appear to be F- or G-type absorption features are detectable in its optical region under the very complex emission-line spectrum; their radial velocity agrees with the CO velocity of the larger cloud in which IC 2144 is embedded. There are significant differences between the spectrum of the brightest area of the nebula and of MWC 778, the presumed illuminator, an issue discussed in some detail. The distance of IC 2144 is inferred to be about 1.0 kpc by reference to other star-forming regions in the vicinity. The extinction is large, as demonstrated by [ Fe II] emission-line ratios in the NIR and by the strength of the diffuse interstellar band spectrum; a provisional value of A(V) of 3.0 mag was assumed. The spectral energy distribution of MWC 778 rises steeply beyond about 1 mu m, with a slope characteristic of a Class I source. Integration of the flux distribution leads to an IR luminosity of about 510 L-circle dot. If MWC 778 is indeed an F- or G-type pre-main-sequence star several magnitudes above the zero-age main sequence, a population of faint emission Ha stars would be expected in the vicinity. Such a search, like other investigations that are recommended in this paper, has yet to be carried out.
C1 [Herbig, G. H.] Univ Hawaii, Inst Astron, Honolulu, HI 96822 USA.
[Vacca, William D.] NASA, Ames Res Ctr, SOFIA USRA, Moffett Field, CA 94035 USA.
RP Herbig, GH (reprint author), Univ Hawaii, Inst Astron, Honolulu, HI 96822 USA.
EM herbig@ifa.hawaii.edu; wvacca@sofia.usra.edu
FU U. S. National Science Foundation [AST 02-04021, AST 07-02941]
FX G. H. was partially supported during this investigation by the U. S.
National Science Foundation under grants AST 02-04021 and AST 07-02941.
We are grateful for access to the SIMBAD database at CDS, Strasbourg,
France, to Colin Aspin and Bo Reipurth for comments, and to Marshall
Perrin for making his thesis available and for a valuable comment.
NR 36
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PI BRISTOL
PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND
SN 0004-6256
J9 ASTRON J
JI Astron. J.
PD NOV
PY 2008
VL 136
IS 5
BP 1995
EP 2010
DI 10.1088/0004-6256/136/5/1995
PG 16
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 361MT
UT WOS:000260132500023
ER
PT J
AU Pryor, W
Gangopadhyay, P
Sandel, B
Forrester, T
Quemerais, E
Moebius, E
Esposito, L
Stewart, I
McClintock, W
Jouchoux, A
Colwell, J
Izmodenov, V
Malama, Y
Tobiska, K
Shemansky, D
Ajello, J
Hansen, C
Bzowski, M
AF Pryor, W.
Gangopadhyay, P.
Sandel, B.
Forrester, T.
Quemerais, E.
Moebius, E.
Esposito, L.
Stewart, I.
McClintock, W.
Jouchoux, A.
Colwell, J.
Izmodenov, V.
Malama, Y.
Tobiska, K.
Shemansky, D.
Ajello, J.
Hansen, C.
Bzowski, M.
TI Radiation transport of heliospheric Lyman-alpha from combined Cassini
and Voyager data sets
SO ASTRONOMY & ASTROPHYSICS
LA English
DT Article
DE ISM: atoms; interplanetary medium; Sun: UV radiation
ID LOCAL INTERSTELLAR-MEDIUM; INTERPLANETARY HYDROGEN DENSITY; SOLAR
RESONANCE RADIATION; INTER-STELLAR MEDIUM; MULTIPLE-SCATTERING;
TERMINATION SHOCK; WIND; IRRADIANCE; ABSORPTION; PARAMETERS
AB Aims. Heliospheric neutral hydrogen scatters solar Lyman-alpha radiation from the Sun with "27-day" intensity modulations observed near Earth due to the Sun's rotation combined with Earth's orbital motion. These modulations are increasingly damped in amplitude at larger distances from the Sun due to multiple scattering in the heliosphere, providing a diagnostic of the interplanetary neutral hydrogen density independent of instrument calibration.
Methods. This paper presents Cassini data from 2003-2004 obtained downwind near Saturn at similar to 10 AU that at times show undamped "27-day" waves in good agreement with the single-scattering models of Pryor et al. ( 1992, ApJ, 394, 363). Simultaneous Voyager 1 data from 2003- 2004 obtained upwind at a distance of 88.8-92.6 AU from the Sun show waves damped by a factor of similar to 0.21. The observed degree of damping is interpreted in terms of Monte Carlo multiple-scattering calculations ( e. g., Keller et al. 1981, A& A, 102, 415) applied to two heliospheric hydrogen two-shock density distributions ( discussed in Gangopadhyay et al. 2006, ApJ, 637, 786) calculated in the frame of the Baranov-Malama model of the solar wind interaction with the two-component ( neutral hydrogen and plasma) interstellar wind (Baranov & Malama 1993, J. Geophys. Res., 98, 15157; Izmodenov et al. 2001, J. Geophys. Res., 106, 10681; Baranov & Izmodenov 2006, Fluid Dyn., 41, 689).
Results. We conclude that multiple scattering is definitely occurring in the outer heliosphere. Both models compare favorably to the data, using heliospheric neutral H densities at the termination shock of 0.085 cm(-3) and 0.095 cm(-3). This work generally agrees with earlier discussions of Voyager data in Quemerais et al. ( 1996, ApJ, 463, 349) showing the importance of multiple scattering but is based on Voyager data obtained at larger distances from the Sun ( with larger damping) simultaneously with Cassini data obtained closer to the Sun. Key words. ISM: atoms
C1 [Pryor, W.] Cent Arizona Coll, Coolidge, AZ 85228 USA.
[Pryor, W.; Tobiska, K.; Shemansky, D.] Space Environm Technol, Pacific Palisades, CA 90272 USA.
[Gangopadhyay, P.] Univ So Calif, Dept Phys, Ctr Space Sci & Astrophys, Los Angeles, CA 90089 USA.
[Sandel, B.; Forrester, T.] Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA.
[Quemerais, E.] CNRS, Serv Aeron, F-91371 Verrieres Le Buisson, France.
[Moebius, E.] Univ New Hampshire, Dept Phys, Durham, NH 03824 USA.
[Esposito, L.; Stewart, I.; McClintock, W.; Jouchoux, A.] Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80303 USA.
[Colwell, J.] Univ Cent Florida, Dept Phys, Orlando, FL 32816 USA.
[Izmodenov, V.] Moscow MV Lomonosov State Univ, Dept Aeromech & Gas Dynam, Sch Mech & Math, Moscow 119899, Russia.
[Izmodenov, V.; Malama, Y.] Russian Acad Sci, Space Res Inst IKI, Moscow 117526, Russia.
[Izmodenov, V.; Malama, Y.] Russian Acad Sci, Inst Problems Mech, Moscow 117526, Russia.
[Ajello, J.; Hansen, C.] Jet Prop Lab, Pasadena, CA 91109 USA.
[Bzowski, M.] Polish Acad Sci, Space Res Ctr, PL-00716 Warsaw, Poland.
RP Pryor, W (reprint author), Cent Arizona Coll, 8470 N Overfield Rd, Coolidge, AZ 85228 USA.
EM wayne.pryor@centralaz.edu
RI Izmodenov, Vladislav/K-6073-2012
OI Izmodenov, Vladislav/0000-0002-1748-0982
FU ISSI, the International Space Science Institute, is based in Bern,
Switzerland; NASA Heliospheric Missions Guest Investigator Program; NASA
JPL Cassini Project; Hampton University; Central Arizona College;
University of Colorado; University of Southern California High
Performance Computing and Communication (HPCC) center; NASA [NNG04GB80G,
NNG06GD55G]; RFBR [05-02-22000(PICS), 07-02-01101, 06-02-7255];
"Dynastia" Foundation
FX We acknowledge support from two ISSI team projects to evaluate
interstellar H parameters. ISSI, the International Space Science
Institute, is based in Bern, Switzerland. Wayne Pryor also acknowledges
support from the NASA Heliospheric Missions Guest Investigator Program,
the NASA JPL Cassini Project, Hampton University, Central Arizona
College and the University of Colorado. It is a pleasure to acknowledge
the computational support given by the University of Southern California
High Performance Computing and Communication (HPCC) center. Pradip
Gangopadhyay was supported in part by NASA grant NNG04GB80G. Eberhard
Mobius gratefully acknowledges support for this study from NASA grant
NNG06GD55G. V. Izmodenov was supported by RFBR grants 05-02-22000(PICS),
07-02-01101 and "Dynastia" Foundation. Yu. G. Malama was supported by
RFBR grant 06-02-7255. Tom Woods provided the composite Lyman-alpha data
used in this analysis. We acknowledge helpful discussions with Priscilla
Frisch on the heliospheric boundary conditions.
NR 57
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PI LES ULIS CEDEX A
PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A,
FRANCE
SN 0004-6361
J9 ASTRON ASTROPHYS
JI Astron. Astrophys.
PD NOV
PY 2008
VL 491
IS 1
BP 21
EP 28
DI 10.1051/0004-6361:20078862
PG 8
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 367NW
UT WOS:000260559700003
ER
PT J
AU Pelangeon, A
Atteia, JL
Nakagawa, YE
Hurley, K
Yoshida, A
Vanderspek, R
Suzuki, M
Kawai, N
Pizzichini, G
Boer, M
Braga, J
Crew, G
Donaghy, TQ
Dezalay, JP
Doty, J
Fenimore, EE
Galassi, M
Graziani, C
Jernigan, JG
Lamb, DQ
Levine, A
Manchanda, J
Martel, F
Matsuoka, M
Olive, JF
Prigozhin, G
Ricker, GR
Sakamoto, T
Shirasaki, Y
Sugita, S
Takagishi, K
Tamagawa, T
Villasenor, J
Woosley, SE
Yamauchi, M
AF Pelangeon, A.
Atteia, J.-L.
Nakagawa, Y. E.
Hurley, K.
Yoshida, A.
Vanderspek, R.
Suzuki, M.
Kawai, N.
Pizzichini, G.
Boer, M.
Braga, J.
Crew, G.
Donaghy, T. Q.
Dezalay, J. P.
Doty, J.
Fenimore, E. E.
Galassi, M.
Graziani, C.
Jernigan, J. G.
Lamb, D. Q.
Levine, A.
Manchanda, J.
Martel, F.
Matsuoka, M.
Olive, J.-F.
Prigozhin, G.
Ricker, G. R.
Sakamoto, T.
Shirasaki, Y.
Sugita, S.
Takagishi, K.
Tamagawa, T.
Villasenor, J.
Woosley, S. E.
Yamauchi, M.
TI Intrinsic properties of a complete sample of HETE-2 gamma-ray bursts A
measure of the GRB rate in the Local Universe
SO ASTRONOMY & ASTROPHYSICS
LA English
DT Review
DE gamma rays: bursts; X-rays: bursts
ID TIME RADIO OBSERVATIONS; 25 APRIL 1998; PROMPT EMISSION; STAR-FORMATION;
HOST GALAXY; E-P,E-I-E-ISO CORRELATION; LUMINOSITY FUNCTION; REDSHIFT
INDICATOR; UNUSUAL SUPERNOVA; SPECTRAL-ANALYSIS
AB Context. As a result of the numerous missions dedicated to the detection of Gamma-ray bursts (GRBs), the observed properties of these events are now well known. However, studying their parameters in the source frame is not simple since it requires having measurements of both the bursts' parameters and of their distances.
Aims. Taking advantage of the forthcoming Catalog of the High Energy Transient Explorer 2 (HETE-2) mission, the aim of this paper is to evaluate the main properties of HETE-2 GRBs - the peak energy (E(peak)), the duration (T(90)) and the isotropic energy (E(iso)) - in their source frames and to derive their unbiased distribution.
Methods. We first construct a complete sample containing all the bursts localized by the Wide-Field X-ray Monitor (WXM) on-board HETE-2, which are selected with a uniform criterion and whose observed parameters can be constrained. We then derive the intrinsic E(peak), T(90) and E(is)o distributions using their redshift when it is available, or their pseudo-redshift otherwise. We finally compute the "volume of detectability" V(max) of each GRB, i.e. the volume of the universe in which the burst is bright enough to be part of our sample, and the corresponding number of GRB within their visibility volume N(Vmax), in order to derive a weight for each detected burst accounting both for the detection significance and the star formation history of the universe.
Results. We obtain unbiased distributions of three intrinsic properties of HETE-2 GRBs: E(peak)(intr), T(90)(intr) and the isotropic energy of the burst. These distributions clearly show the predominence of X-ray flashes (XRFs) in the global GRB population. We also derive the rate of local GRBs: R(0)(H2) greater than or similar to 11 Gpc(-3) yr(-1), which is intermediate between the local rate obtained by considering only the "high-luminosity" bursts (similar to 1 Gpc(-3) yr(-1)) and that obtained by including the "low-luminosity" bursts (greater than or similar to 200 Gpc(-3) yr(-1)).
Conclusions. This study shows that the XRFs are predominent in the GRB population and are closely linked to the "classical" GRBs. We show that HETE-2 detected no low-luminosity GRB like GRB 980425 or XRF 060218, due to the small size of its detectors, excluding this type of burst from our statistical analysis. The comparison of the GRB rate derived in this study with the known rate of type Ib/c supernovae clearly shows that the progenitors of SNe Ib/c must have some special characteristics in order to produce a gamma- ray burst or an X-ray flash.
C1 [Pelangeon, A.; Atteia, J.-L.] Univ Toulouse, CNRS, Lab Astrophys Toulouse Tarbes, F-31400 Toulouse, France.
[Nakagawa, Y. E.; Yoshida, A.] Aoyama Gakuin Univ, Dept Math & Phys, Kanagawa 2298558, Japan.
[Nakagawa, Y. E.; Yoshida, A.; Kawai, N.; Tamagawa, T.] RIKEN, Inst Phys & Chem Res, Wako, Saitama 3510198, Japan.
[Vanderspek, R.; Crew, G.; Doty, J.; Levine, A.; Martel, F.; Prigozhin, G.; Ricker, G. R.; Villasenor, J.] MIT, Ctr Space Res, Cambridge, MA 02139 USA.
[Jernigan, J. G.] Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA.
[Kawai, N.] Tokyo Inst Technol, Dept Phys, Meguro Ku, Tokyo 1528551, Japan.
[Pizzichini, G.] INAF IASF Bologna, I-40129 Bologna, Italy.
[Boer, M.] St Michael Observ, CNRS, OAMP, Observ Haute Provence, Paris, France.
[Braga, J.] Inst Nacl Pesquisas Espaciais, BR-12227010 Sao Jose Dos Campos, Brazil.
[Donaghy, T. Q.; Graziani, C.; Lamb, D. Q.] Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA.
[Dezalay, J. P.] Univ Toulouse, CNRS, Ctr Etud Spatiale Rayonnements, F-31028 Toulouse, France.
[Fenimore, E. E.; Galassi, M.] Los Alamos Natl Lab, Los Alamos, NM 87545 USA.
[Manchanda, J.] Tata Inst Fundamental Res, Dept Astron & Astrophys, Mumbai 400005, Maharashtra, India.
[Suzuki, M.; Matsuoka, M.] Natl Space Dev Agcy Japan, Tsukuba Space Ctr, Tsukuba, Ibaraki 3058505, Japan.
[Sakamoto, T.] NASA, Goddard Space Flight Ctr, CRESST, Greenbelt, MD 20771 USA.
[Shirasaki, Y.] Natl Astron Observ, Mitaka, Tokyo 1818588, Japan.
[Sugita, S.] Aoyama Gakuin Univ, Dept Phys, Setagaya Ku, Tokyo 1578572, Japan.
[Takagishi, K.; Yamauchi, M.] Miyazaki Univ, Fac Engn, Miyazaki 8892192, Japan.
[Woosley, S. E.] Univ Calif Santa Cruz, Dept Astron & Astrophys, Santa Cruz, CA 95064 USA.
[Sakamoto, T.] Univ Maryland, Joint Astron Ctr, Baltimore, MD 21250 USA.
RP Pelangeon, A (reprint author), Univ Toulouse, CNRS, Lab Astrophys Toulouse Tarbes, 14 Av Edouard Belin, F-31400 Toulouse, France.
EM alexandre.pelangeon@ast.obs-mip.fr; atteia@ast.obs-mip.fr
FU NASA [NASW-4690]; CNES [793-01-8479]; Ministry of Education, Culture,
Sports, Science and Technology [19047001]; Ministry of National
Education, Research and Technology; JSPS Research Fellowships for Young
Scientists; RIKEN; MIT [SC-R-293291]; ASI [I/088/06/0]
FX The HETE-2 mission was supported in the US by NASA contract NASW-4690,
in France by CNES contract 793-01-8479 and in Japan in part by the
Ministry of Education, Culture, Sports, Science and Technology and by
Grant-in-Aid for Scientific Research on Priority Areas 19047001. The
authors acknowledge the valuable support of the HETE-2 Operation Team.
AP is supported in France by the Ministry of National Education,
Research and Technology. Y.E.N. is supported by the JSPS Research
Fellowships for Young Scientists. This work is supported in part by a
special postdoctoral researchers program in RIKEN. K. H. is grateful for
support under MIT Contract SC-R-293291. G. Pizzichini aknowledges
financial support as part of ASI contract I/088/06/0. Finally, the
authors acknowledge the referee for his/her valuable and relevant
remarks that helped improving the content of this paper.
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FRANCE
SN 0004-6361
J9 ASTRON ASTROPHYS
JI Astron. Astrophys.
PD NOV
PY 2008
VL 491
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BP 157
EP U67
DI 10.1051/0004-6361:200809709
PG 19
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 367NW
UT WOS:000260559700012
ER
PT J
AU Piranomonte, S
D'Avanzo, P
Covino, S
Antonelli, LA
Beardmore, AP
Campana, S
Chincarini, G
D'Elia, V
Della Valle, M
Fiore, F
Fugazza, D
Guetta, D
Guidorzi, C
Israel, GL
Lazzati, D
Malesani, D
Parsons, AM
Perna, R
Stella, L
Tagliaferri, G
Vergani, SD
AF Piranomonte, S.
D'Avanzo, P.
Covino, S.
Antonelli, L. A.
Beardmore, A. P.
Campana, S.
Chincarini, G.
D'Elia, V.
Della Valle, M.
Fiore, F.
Fugazza, D.
Guetta, D.
Guidorzi, C.
Israel, G. L.
Lazzati, D.
Malesani, D.
Parsons, A. M.
Perna, R.
Stella, L.
Tagliaferri, G.
Vergani, S. D.
TI The short GRB 070707 afterglow and its very faint host galaxy
SO ASTRONOMY & ASTROPHYSICS
LA English
DT Article
DE gamma rays: bursts
ID GAMMA-RAY BURSTS; SHORT-DURATION GRBS; HIGH-REDSHIFT; VELOCITY
DISPERSIONS; LIGHT CURVES; GIANT FLARE; SUPERNOVAE; CLUSTERS;
PROGENITORS; LUMINOSITY
AB We present the results from an ESO/VLT campaign aimed at studying the afterglow properties of the short/hard gamma ray burst GRB 070707. Observations were carried out at ten different epochs from similar to 0.5 to similar to 80 days after the event. The optical flux decayed steeply with a power-law decay index greater than 3, later levelling off at R similar to 27.3 mag; this is likely the emission level of the host galaxy, the faintest yet detected for a short GRB. Spectroscopic observations did not reveal any line features/edges that could unambiguously pinpoint the GRB redshift, but set a limit z < 3.6. In the range of allowed redshifts, the host has a low luminosity, comparable to that of long-duration GRBs. The existence of such faint host galaxies suggests caution when associating short GRBs with bright, offset galaxies, where the true host might just be too dim for detection. The steepness of the decay of the optical afterglow of GRB 070707 challenges external shock models for the optical afterglow of short/hard GRBs. We argue that this behaviour might result from prolonged activity of the central engine or require alternative scenarios.
C1 [Piranomonte, S.; Antonelli, L. A.; D'Elia, V.; Fiore, F.; Guetta, D.; Israel, G. L.; Stella, L.] INAF Osservatorio Astron Roma, I-00040 Monte Porzio Catone, RM, Italy.
[D'Avanzo, P.; Covino, S.; Campana, S.; Chincarini, G.; Fugazza, D.; Guidorzi, C.; Tagliaferri, G.] INAF Osservatorio Astron Brera, I-23807 Merate, LC, Italy.
[Beardmore, A. P.] Univ Leicester, Dept Phys & Astron, Leicester LE1 7RH, Leics, England.
[Chincarini, G.] Univ Milano Bicocca, Dipartimento Fis, I-20126 Milan, Italy.
[Della Valle, M.] INAF Osservatorio Astron Capodimonte, I-80131 Naples, Italy.
[Della Valle, M.] European So Observ, D-85748 Garching, Germany.
[Della Valle, M.] Int Ctr Relativist Astrophys Network, I-65122 Pescara, Italy.
[Lazzati, D.; Perna, R.] Univ Colorado, JILA, Boulder, CO 80309 USA.
[Lazzati, D.] N Carolina State Univ, Dept Phys, Raleigh, NC 27695 USA.
[Malesani, D.] Univ Copenhagen, Niels Bohr Inst, Dark Cosmol Ctr, DK-2100 Kobenavn O, Denmark.
[Parsons, A. M.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
[Vergani, S. D.] DIAS, Dunsink Observ, Dublin 15, Ireland.
[Vergani, S. D.] Dublin City Univ, Sch Phys Sci, Dublin 9, Ireland.
[Vergani, S. D.] Dublin City Univ, NCPST, Dublin 9, Ireland.
RP Piranomonte, S (reprint author), INAF Osservatorio Astron Roma, Via Frascati 33, I-00040 Monte Porzio Catone, RM, Italy.
EM piranomonte@oa-roma.inaf.it
RI Parsons, Ann/I-6604-2012;
OI Tagliaferri, Gianpiero/0000-0003-0121-0723; guetta,
dafne/0000-0002-7349-1109; D'Elia, Valerio/0000-0002-7320-5862; Vergani,
Daniela/0000-0003-0898-2216; Della Valle, Massimo/0000-0003-3142-5020;
Fiore, Fabrizio/0000-0002-4031-4157; Covino, Stefano/0000-0001-9078-5507
FU MIUR [COFIN-03-02-23, INAF/PRIN 270/2003]; ASI [ASI/I/R/039/04,
ASI/I/R/023/05/0]; SFI; Danish National Research Foundation; STFC
FX We thank an anonymous referee for comments. We thank D. A. Kann and A.
Dar for useful discussion. Part of this work was supported by MIUR
COFIN-03-02-23 and INAF/PRIN 270/2003 and ASI contracts ASI/I/R/039/04
and ASI/I/R/023/05/0. S. D. V. is supported by SFI. The Dark Cosmology
Centre is funded by the Danish National Research Foundation. A. P. B. is
supported by STFC.
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JI Astron. Astrophys.
PD NOV
PY 2008
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SC Astronomy & Astrophysics
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ER
PT J
AU Giuliani, A
Mereghetti, S
Fornari, F
Del Monte, E
Feroci, M
Marisaldi, M
Esposito, P
Perotti, F
Tavani, M
Argan, A
Barbiellini, G
Boffelli, F
Bulgarelli, A
Caraveo, P
Cattaneo, PW
Chen, AW
Costa, E
D'Ammando, F
Di Cocco, G
Donnarumma, I
Evangelista, Y
Fiorini, M
Fuschino, F
Galli, M
Gianotti, F
Labanti, C
Lapshov, I
Lazzarotto, F
Lipari, P
Longo, F
Morselli, A
Pacciani, L
Pellizzoni, A
Piano, G
Picozza, P
Prest, M
Pucella, G
Rapisarda, M
Rappoldi, A
Soffitta, P
Trifoglio, M
Trois, A
Vallazza, E
Vercellone, S
Zanello, D
Salotti, L
Cutini, S
Pittori, C
Preger, B
Santolamazza, P
Verrecchia, F
Gehrels, N
Page, K
Burrows, D
Rossi, A
Hurley, K
Mitrofanov, I
Boynton, W
AF Giuliani, A.
Mereghetti, S.
Fornari, F.
Del Monte, E.
Feroci, M.
Marisaldi, M.
Esposito, P.
Perotti, F.
Tavani, M.
Argan, A.
Barbiellini, G.
Boffelli, F.
Bulgarelli, A.
Caraveo, P.
Cattaneo, P. W.
Chen, A. W.
Costa, E.
D'Ammando, F.
Di Cocco, G.
Donnarumma, I.
Evangelista, Y.
Fiorini, M.
Fuschino, F.
Galli, M.
Gianotti, F.
Labanti, C.
Lapshov, I.
Lazzarotto, F.
Lipari, P.
Longo, F.
Morselli, A.
Pacciani, L.
Pellizzoni, A.
Piano, G.
Picozza, P.
Prest, M.
Pucella, G.
Rapisarda, M.
Rappoldi, A.
Soffitta, P.
Trifoglio, M.
Trois, A.
Vallazza, E.
Vercellone, S.
Zanello, D.
Salotti, L.
Cutini, S.
Pittori, C.
Preger, B.
Santolamazza, P.
Verrecchia, F.
Gehrels, N.
Page, K.
Burrows, D.
Rossi, A.
Hurley, K.
Mitrofanov, I.
Boynton, W.
TI AGILE detection of delayed gamma-ray emission from GRB 080514B
SO ASTRONOMY & ASTROPHYSICS
LA English
DT Article
DE gamma rays: bursts
ID HIGH-ENERGY; BURST; SUPERAGILE
AB GRB 080514B is the first gamma ray burst (GRB), since the time of EGRET, for which individual photons of energy above several tens of MeV have been detected with a pair-conversion tracker telescope. This burst was discovered with the Italian AGILE gamma-ray satellite. The GRB was localized by a cooperation between AGILE and the interplanetary network (IPN). The gamma-ray imager ( GRID) estimate of the position, obtained before the SuperAGILE-IPN localization, is found to be consistent with the burst position. The hard X-ray emission observed by SuperAGILE lasted about 7 s, while there is evidence that the emission above 30 MeV extends for a longer duration ( at least 13 s). Similar behavior has been seen from a few other GRBs observed with EGRET. However, during the brightest phases, the latter measurements were affected by instrumental dead time effects, resulting in only lower limits to the burst intensity. Thanks to the small dead time of the AGILE/GRID we could assess that in the case of GRB 080514B the gamma-ray to X-ray flux ratio changes significantly between the prompt and extended emission phase.
C1 [Giuliani, A.; Mereghetti, S.; Fornari, F.; Esposito, P.; Perotti, F.; Caraveo, P.; Chen, A. W.; Fiorini, M.; Pellizzoni, A.; Vercellone, S.] INAF IASF Milano, I-20133 Milan, Italy.
[Chen, A. W.] CIFS Torino, I-10133 Turin, Italy.
[Del Monte, E.; Feroci, M.; Tavani, M.; Argan, A.; Costa, E.; D'Ammando, F.; Donnarumma, I.; Evangelista, Y.; Lapshov, I.; Lazzarotto, F.; Pacciani, L.; Piano, G.; Pucella, G.; Soffitta, P.; Trois, A.] INAF IASF Roma, I-00133 Rome, Italy.
[Tavani, M.; D'Ammando, F.; Piano, G.] Univ Roma Tor Vergata, Dip Fis, I-00133 Rome, Italy.
[Marisaldi, M.; Bulgarelli, A.; Di Cocco, G.; Fuschino, F.; Gianotti, F.; Labanti, C.; Trifoglio, M.] INAF IASF Bologna, I-40129 Bologna, Italy.
[Barbiellini, G.; Longo, F.; Vallazza, E.] Ist Nazl Fis Nucl, I-34127 Trieste, Italy.
[Barbiellini, G.; Longo, F.; Vallazza, E.] Dip Fis, I-34127 Trieste, Italy.
[Esposito, P.; Boffelli, F.; Cattaneo, P. W.; Rappoldi, A.] Ist Nazl Fis Nucl, I-27100 Pavia, Italy.
[Cutini, S.; Pittori, C.; Preger, B.; Santolamazza, P.; Verrecchia, F.] ASI ASDC, I-00044 Frascati, Roma, Italy.
[Morselli, A.; Picozza, P.] INFN Roma Tor Vergata, I-00133 Rome, Italy.
[Prest, M.] Univ Insubria, Dip Fis, I-22100 Como, Italy.
[Rapisarda, M.] ENEA, I-00044 Frascati, Roma, Italy.
[Lipari, P.; Zanello, D.] INFN Roma La Sapienza, I-00185 Rome, Italy.
[Salotti, L.] ASI, I-00198 Rome, Italy.
[Galli, M.] ENEA, I-40129 Bologna, Italy.
[Gehrels, N.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
[Page, K.] Univ Leicester, Dept Phys & Astron, Leicester LE1 7RH, Leics, England.
[Burrows, D.] Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA.
[Esposito, P.; Boffelli, F.] Univ Pavia, Dipartimento Fis Nucl & Teor, I-27100 Pavia, Italy.
[Rossi, A.] Thuringer Landessternwarte Tautenburg, D-07778 Tautenburg, Germany.
[Hurley, K.] Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA.
[Mitrofanov, I.] Moscow Space Res Inst, Moscow 117997, Russia.
[Boynton, W.] Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA.
RP Giuliani, A (reprint author), INAF IASF Milano, Via E Bassini 15, I-20133 Milan, Italy.
EM giuliani@iasf-milano.inaf.it
RI Rossi, Andrea/N-4674-2015; Gehrels, Neil/D-2971-2012; Morselli,
Aldo/G-6769-2011; Lazzarotto, Francesco/J-4670-2012; Trifoglio,
Massimo/F-5302-2015; Pittori, Carlotta/C-7710-2016;
OI PREST, MICHELA/0000-0003-3161-4454; Verrecchia,
Francesco/0000-0003-3455-5082; Marisaldi, Martino/0000-0002-4000-3789;
Vercellone, Stefano/0000-0003-1163-1396; MEREGHETTI,
SANDRO/0000-0003-3259-7801; Esposito, Paolo/0000-0003-4849-5092; Tavani,
Marco/0000-0003-2893-1459; Cutini, Sara/0000-0002-1271-2924; Fiorini,
Mauro/0000-0001-8297-1983; Bulgarelli, Andrea/0000-0001-6347-0649;
Pacciani, Luigi/0000-0001-6897-5996; trois, alessio/0000-0002-3180-6002;
Donnarumma, Immacolata/0000-0002-4700-4549; Pellizzoni, Alberto
Paolo/0000-0002-4590-0040; Labanti, Claudio/0000-0002-5086-3619; Feroci,
Marco/0000-0002-7617-3421; Soffitta, Paolo/0000-0002-7781-4104; Picozza,
Piergiorgio/0000-0002-7986-3321; Rossi, Andrea/0000-0002-8860-6538;
Caraveo, Patrizia/0000-0003-2478-8018; Morselli,
Aldo/0000-0002-7704-9553; Gianotti, Fulvio/0000-0003-4666-119X;
Lazzarotto, Francesco/0000-0003-4871-4072; Costa,
Enrico/0000-0003-4925-8523; Trifoglio, Massimo/0000-0002-2505-3630;
Pittori, Carlotta/0000-0001-6661-9779; galli,
marcello/0000-0002-9135-3228; Cattaneo, Paolo
Walter/0000-0001-6877-6882; Fuschino, Fabio/0000-0003-2139-3299
FU Italian Space Agency (ASI); STFC; Mars Odyssey Participating Scientist
program, JPL [1282043]
FX The AGILE Mission is funded by the Italian Space Agency (ASI) with
scientific and programmatic participation by the Italian Institute of
Astrophysics (INAF) and the Italian Institute of Nuclear Physics (INFN).
K. L. P. acknowledges financial support from STFC. K. H. is grateful for
support under the Mars Odyssey Participating Scientist program, JPL
grant 1282043.
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SC Astronomy & Astrophysics
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ER
PT J
AU Rossi, A
Postigo, AD
Ferrero, P
Kann, DA
Klose, S
Schulze, S
Greiner, J
Schady, P
Filgas, R
Gonsalves, EE
Yoldas, AK
Kruhler, T
Szokoly, G
Yoldas, A
Afonso, PMJ
Clemens, C
Bloom, JS
Perley, DA
Fynbo, JPU
Castro-Tirado, AJ
Gorosabel, J
Kubanek, P
Updike, AC
Hartmann, DH
Giuliani, A
Holland, ST
Hanlon, L
Bremer, M
French, J
Melady, G
Garcia-Hernandez, DA
AF Rossi, A.
de Ugarte Postigo, A.
Ferrero, P.
Kann, D. A.
Klose, S.
Schulze, S.
Greiner, J.
Schady, P.
Filgas, R.
Gonsalves, E. E.
Yoldas, A. Kuepcue
Kruehler, T.
Szokoly, G.
Yoldas, A.
Afonso, P. M. J.
Clemens, C.
Bloom, J. S.
Perley, D. A.
Fynbo, J. P. U.
Castro-Tirado, A. J.
Gorosabel, J.
Kubanek, P.
Updike, A. C.
Hartmann, D. H.
Giuliani, A.
Holland, S. T.
Hanlon, L.
Bremer, M.
French, J.
Melady, G.
Garcia-Hernandez, D. A.
TI A photometric redshift of z=1.8(-0.3)(+0.4) for the AGILE GRB 080514B
SO ASTRONOMY & ASTROPHYSICS
LA English
DT Article
DE gamma rays: bursts
ID GAMMA-RAY BURSTS; SPECTRAL CATALOG; LIGHT CURVES; HOST-GALAXY; DUST;
EMISSION; AFTERGLOWS; ABSORPTION; GAS
AB The AGILE gamma-ray burst GRB 080514B is the first detected to have emission above 30 MeV and an optical afterglow. However, no spectroscopic redshift for this burst is known. We report on our ground-based optical/NIR and millimeter follow-up observations of this event at several observatories, including the multi-channel imager GROND on La Silla, supplemented by Swift UVOT and Swift XRT data. The spectral energy distribution ( SED) of the optical/NIR afterglow is found to decline sharply bluewards to the UV bands, which can be utilized in estimating the redshift. Fitting the SED from the Swift UVOT uvw2 band to the H band, we estimate a photometric redshift of z = 1.8(-0.3)(+0.4), which is consistent with the reported pseudo-redshift based on gamma-ray data. We find that the afterglow properties of GRB 080514B do not differ from those exhibited by the global sample of long bursts. Compared with the long burst sample, we conclude that this burst was special because of its high-energy emission properties, even though both its afterglow and host galaxy are not remarkable in any way. Obviously, high-energy emission in the gamma-ray band does not automatically correlate with the occurrence of special features in the corresponding afterglow light.
C1 [Rossi, A.; Ferrero, P.; Kann, D. A.; Klose, S.; Schulze, S.; Filgas, R.; Gonsalves, E. E.] Thuringer Landessternwarte Tautenburg, D-07778 Tautenburg, Germany.
[de Ugarte Postigo, A.] European So Observ, Santiago 19, Chile.
[Greiner, J.; Yoldas, A. Kuepcue; Kruehler, T.; Szokoly, G.; Yoldas, A.; Afonso, P. M. J.; Clemens, C.] Max Planck Inst Extraterr Phys, D-85748 Garching, Germany.
[Schady, P.] Univ Coll London, Mullard Space Sci Lab, Dorking RH5 6NT, Surrey, England.
[Gonsalves, E. E.] Dartmouth Coll, Hanover, NH 03755 USA.
[Yoldas, A. Kuepcue] European So Observ, D-85748 Garching, Germany.
[Kruehler, T.] Tech Univ Munich, Universe Cluster, D-85748 Garching, Germany.
[Szokoly, G.] Eotvos Lorand Univ, Inst Phys, H-1117 Budapest, Hungary.
[Bloom, J. S.; Perley, D. A.] Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA.
[Fynbo, J. P. U.] Univ Copenhagen, Niels Bohr Inst, Dark Cosmol Ctr, DK-2100 Copenhagen, Denmark.
[Castro-Tirado, A. J.; Gorosabel, J.; Kubanek, P.] CSIC, IAA, E-18080 Granada, Spain.
[Updike, A. C.; Hartmann, D. H.] Clemson Univ, Dept Phys & Astron, Clemson, SC 29634 USA.
[Giuliani, A.] INAF IASF Milano, I-20133 Milan, Italy.
[Holland, S. T.] Goddard Space Flight Ctr, Astrophys Sci Div, Greenbelt, MD 20771 USA.
[Hanlon, L.; French, J.; Melady, G.] Univ Coll Dublin, Sch Phys, Dublin 4, Ireland.
[Bremer, M.] Inst Radio Astron Millimetr, F-38406 St Martin Dheres, France.
[Garcia-Hernandez, D. A.] Inst Astrofis Canarias, Tenerife 38205, Spain.
[Kubanek, P.] Univ Valencia, Edif Inst Invest GACE ICMOL, Paterna 46980, Spain.
RP Rossi, A (reprint author), Thuringer Landessternwarte Tautenburg, Sternwarte 5, D-07778 Tautenburg, Germany.
EM rossi@tls-tautenburg.de
RI Kubanek, Petr/G-7209-2014
FU DFG [K1 766/11-3]; ESO; Thuringer Landessternwarte; DNRF; J. Gorosabel
[ESP2005-07714-C03-03, AYA2007-63677]; SFI
FX We thank the referee for a very careful reading of the manuscript and a
rapid reply. A. R., P. F. and S. K. acknowledge support by DFG K1
766/11-3, A. D. U. P. by an ESO fellowship, D. A. K., S. S., and R. F.
by the Thuringer Landessternwarte, T. K. by the DFG cluster of
excellence "Origin and Structure of the Universe", J. P. U. F. by the
DNRF, J. Gorosabel by the programmes ESP2005-07714-C03-03 and
AYA2007-63677, and L. H. by SFI. We thank D. Malesani for a careful
reading of the manuscript, P. E. Nissen and W. J. Schuster for
performing the NOT observations as well as A. Pimienta, E. Curras and C.
Pereira for performing the IAC80 observations. This work made use of
data supplied by the UK Swift Science Data Centre at the University of
Leicester.
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SC Astronomy & Astrophysics
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PT J
AU Dorodnitsyn, A
Kallman, T
Proga, D
AF Dorodnitsyn, A.
Kallman, T.
Proga, D.
TI AN AXISYMMETRIC, HYDRODYNAMICAL MODEL FOR THE TORUS WIND IN ACTIVE
GALACTIC NUCLEI. II. X-RAY-EXCITED FUNNEL FLOW
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE acceleration of particles; galaxies: active; hydrodynamics; methods:
numerical; quasars: absorption lines; X-rays: galaxies
ID REFLECTION GRATING SPECTROMETER; HUBBLE-SPACE-TELESCOPE; IONIZED-GAS;
RADIATION PRESSURE; SEYFERT-GALAXIES; ANGULAR-MOMENTUM; WARM ABSORBERS;
STELLAR WINDS; HEATED WINDS; NGC-1068
AB We have calculated a series of models of outflows from the obscuring torus in active galactic nuclei (AGNs). Our modeling assumes that the inner face of a rotationally supported torus is illuminated and heated by the intense X-rays from the inner accretion disk and black hole. As a result of such heating, a strong biconical outflow is observed in our simulations. We calculate three-dimensional hydrodynamical models, assuming axial symmetry and including the effects of X-ray heating, ionization, and radiation pressure. We discuss the behavior of a large family of these models, their velocity fields, mass fluxes, and temperature, as functions of the torus properties and X-ray flux. Synthetic warm-absorber spectra are calculated, assuming pure absorption, for sample models at various inclination angles and observing times. We show that these models have mass fluxes and flow speeds comparable to those inferred from observations of Seyfert 1 warm absorbers, and that they can produce rich absorption-line spectra.
C1 [Dorodnitsyn, A.; Kallman, T.] NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA.
[Dorodnitsyn, A.] Space Res Inst, Moscow 117997, Russia.
[Proga, D.] Univ Nevada, Dept Phys & Astron, Las Vegas, NV 89154 USA.
RP Dorodnitsyn, A (reprint author), NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Code 662, Greenbelt, MD 20771 USA.
FU NASA Goddard Space Flight Center; Oak Ridge Associated Universities
through a contract with NASA; NASA Astrophysics Theory Program
[05-ATP05-18]
FX This research was supported by an appointment to the NASA Postdoctoral
Program at the NASA Goddard Space Flight Center, administered by Oak
Ridge Associated Universities through a contract with NASA and by grants
from the NASA Astrophysics Theory Program 05-ATP05-18. We would like to
thank the referee for many constructive comments, which have led to
improvement of the manuscript.
NR 46
TC 23
Z9 23
U1 0
U2 2
PU IOP PUBLISHING LTD
PI BRISTOL
PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND
SN 0004-637X
EI 1538-4357
J9 ASTROPHYS J
JI Astrophys. J.
PD NOV 1
PY 2008
VL 687
IS 1
BP 97
EP 110
DI 10.1086/591418
PG 14
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 364YD
UT WOS:000260370800009
ER
PT J
AU Stutz, AM
Rubin, M
Werner, MW
Rieke, GH
Bieging, JH
Keene, J
Kang, MJ
Shirley, YL
Su, KYL
Velusamy, T
Wilner, DJ
AF Stutz, Amelia M.
Rubin, Mark
Werner, Michael W.
Rieke, George H.
Bieging, John H.
Keene, Jocelyn
Kang, Miju
Shirley, Yancy L.
Su, K. Y. L.
Velusamy, Thangasamy
Wilner, David J.
TI SPITZER AND HHT OBSERVATIONS OF BOK GLOBULE B335: ISOLATED STAR
FORMATION EFFICIENCY AND CLOUD STRUCTURE
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE infrared: ISM; ISM: globules; ISM: individual (Barnard 335); stars:
formation
ID SPECTRAL ENERGY-DISTRIBUTIONS; MULTIBAND IMAGING PHOTOMETER;
FAR-INFRARED OBSERVATIONS; INTERSTELLAR DUST GRAINS; YOUNG STELLAR
OBJECTS; LOW-MASS STARS; PROTOSTELLAR COLLAPSE; MOLECULAR CLOUDS;
SPACE-TELESCOPE; CONTINUUM OBSERVATIONS
AB We present infrared and millimeter observations of Barnard 335, the prototypical isolated Bok globule with an embedded protostar. Using Spitzer data we measure the source luminosity accurately; we also constrain the density profile of the innermost globule material near the protostar using the observation of an 8.0 mu m shadow. Heinrich Hertz Telescope (HHT) observations of (12)CO 2-1 confirm the detection of a flattened molecular core with diameter similar to 10,000 AU and the same orientation as the circumstellar disk (similar to 100 to 200 AU in diameter). This structure is probably the same as that generating the 8.0 mu m shadow and is expected from theoretical simulations of collapsing embedded protostars. We estimate the mass of the protostar to be only similar to 5% of the mass of the parent globule.
C1 [Stutz, Amelia M.; Rieke, George H.; Bieging, John H.; Kang, Miju; Shirley, Yancy L.; Su, K. Y. L.] Univ Arizona, Dept Astron, Tucson, AZ 85721 USA.
[Stutz, Amelia M.; Rieke, George H.; Bieging, John H.; Kang, Miju; Shirley, Yancy L.; Su, K. Y. L.] Univ Arizona, Steward Observ, Tucson, AZ 85721 USA.
[Rubin, Mark; Werner, Michael W.; Velusamy, Thangasamy] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[Keene, Jocelyn] CALTECH, Pasadena, CA 91125 USA.
[Kang, Miju] Korea Astron & Space Sci Inst, Taejon 305348, South Korea.
[Kang, Miju] Chungnam Natl Univ, Dept Astron & Space Sci, Taejon 305348, South Korea.
[Wilner, David J.] Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA.
RP Stutz, AM (reprint author), Univ Arizona, Dept Astron, 933 N Cherry Ave, Tucson, AZ 85721 USA.
EM astutz@as.arizona.edu
FU Jet Propulsion Laboratory, California Institute of Technology; National
Aeronautics and Space Administration; Caltech/JPL to the University of
Arizona [1255094]; National Science Foundation [AST-0708131]; University
of Arizona [KRF-2007-612-C00050]
FX We thank Kevin M. Flaherty, Fabian Heitsch, and Craig Kulesa for helpful
comments. We thank Thomas Robitaille for his help with model fitting.
The authors also thank the anonymous referee for helpful comments that
improved the text. A. M. S. thanks the c2d team members for insightful
comments. Portions of this work were carried out at the Jet Propulsion
Laboratory, California Institute of Technology, under contract with the
National Aeronautics and Space Administration. This work was supported
by contract 1255094 issued by Caltech/JPL to the University of Arizona.
This work was supported in part by National Science Foundation grant
AST-0708131 to the University of Arizona. M. K. was supported by the
KRF-2007-612-C00050 grant.
NR 73
TC 30
Z9 30
U1 0
U2 8
PU IOP PUBLISHING LTD
PI BRISTOL
PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD NOV 1
PY 2008
VL 687
IS 1
BP 389
EP 405
DI 10.1086/591789
PG 17
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 364YD
UT WOS:000260370800030
ER
PT J
AU Choi, M
Hamaguchi, K
Lee, JE
Tatematsu, K
AF Choi, Minho
Hamaguchi, Kenji
Lee, Jeong-Eun
Tatematsu, Ken'ichi
TI CENTIMETER IMAGING OF THE R CORONAE AUSTRALIS REGION
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE ISM: individual (R Coronae Australis IRS 7); ISM: structure; stars:
formation
ID YOUNG STELLAR OBJECTS; STAR-FORMING REGIONS; X-RAY-EMISSION;
MAIN-SEQUENCE STARS; TRIPLE RADIO-SOURCE; T-TAURI STARS; MOLECULAR
CLOUD; CONTINUUM SOURCES; PROTOSTELLAR JET; HIGH-RESOLUTION
AB The R CrA region was observed in the 3.5 and 6.2 cm continuum with high angular resolutions (0.6 ''-1.7 ''). Archival data sets were also analyzed for comparison. IRS 7A showed an enhanced outflow activity recently. The main peak of IRS 7A positionally coincides with an X-ray source, suggesting that the X-ray emission is directly related to the central protostar. The Class 0 source SMA 2 is associated with a double radio source, B9a/b, and seems to be driving two outflows. The B9 complex is probably a multiple-protostar system. IRS 7B is a compact radio source surrounded by an extended structure. The compact source corresponds to the Class 0/I source SMA 1 and is closely associated with an X-ray source, suggesting that magnetic activity starts early in the protostellar stage of evolution. IRS 5 was resolved into two sources, and they display radio flares and X-ray emission, suggesting that energetic magnetic processes are active in both members. The month-scale active phase of IRS 5b implies that the flare activity must involve large-scale magnetic fields. During the strong flare event of IRS 5b in 1998, IRS 5a also showed an enhanced level of emission. This concurrent activity suggests that IRS 5 may be an interacting young binary system. Alternatively, what was seen in the radio images could be a circumbinary halo. The variable radio source B5 was found to be a nonthermal source. Properties of other radio sources, IRS 1, IRS 2, IRS 6, and R CrA, are discussed, and the radio detections of T CrA and WMB55 are reported. Also presented is the classification of infrared sources based on an infrared color-color diagram.
C1 [Choi, Minho] Korea Astron & Space Sci Inst, Int Ctr Astrophys, Taejon 305348, South Korea.
[Hamaguchi, Kenji] NASA, Goddard Space Flight Ctr, Ctr Res & Explorat Space Sci & Technol, Greenbelt, MD 20771 USA.
[Hamaguchi, Kenji] NASA, Goddard Space Flight Ctr, Xray Astrophys Lab, Greenbelt, MD 20771 USA.
[Hamaguchi, Kenji] Univ Maryland Baltimore Cty, Dept Phys, Baltimore, MD 21250 USA.
[Lee, Jeong-Eun] Sejong Univ, Dept Astron & Space Sci, Astrophys Res Ctr Struct & Evolut Cosmos, Seoul 143747, South Korea.
[Tatematsu, Ken'ichi] Natl Astron Observ Japan, Mitaka, Tokyo 1818588, Japan.
RP Choi, M (reprint author), Korea Astron & Space Sci Inst, Int Ctr Astrophys, Hwaam 61-1, Taejon 305348, South Korea.
EM minho@kasi.re.kr
RI Lee , Jeong-Eun/E-2387-2013
FU LRG Program of KASI; NASA Astrobiology Program [CAN 03-OSS-02]; Korea
Science and Engineering Foundation; Astrophysical Research Center for
the Structure and Evolution of the Cosmos; National Radio Astronomy
Observatory; National Science Foundation; University of Massachusetts
and the Infrared Processing and Analysis Center/California Institute of
Technology; National Aeronautics and Space Administration and the
National Science Foundation.
FX We thank K.-H. Kim for helpful discussions. This work was supported by
the LRG Program of KASI. K. H. is supported by the NASA Astrobiology
Program under CAN 03-OSS-02. J.- E. L. gratefully acknowledges the
support by the Korea Science and Engineering Foundation (KOSEF) under a
cooperative agreement with the Astrophysical Research Center for the
Structure and Evolution of the Cosmos (ARCSEC). The National Radio
Astronomy Observatory is a facility of the National Science Foundation
operated under cooperative agreement by Associated Universities, Inc.
This work is based in part on observations made with the Spitzer Space
Telescope, which is operated by the Jet Propulsion Laboratory,
California Institute of Technology, under a contract with NASA. This
publication makes use of data products from the Two Micron All Sky
Survey, which is a joint project of the University of Massachusetts and
the Infrared Processing and Analysis Center/California Institute of
Technology, funded by the National Aeronautics and Space Administration
and the National Science Foundation.
NR 54
TC 16
Z9 16
U1 0
U2 4
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD NOV 1
PY 2008
VL 687
IS 1
BP 406
EP 424
DI 10.1086/591540
PG 19
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 364YD
UT WOS:000260370800031
ER
PT J
AU Hamaguchi, K
Choi, M
Corcoran, MF
Choi, CS
Tatematsu, K
Petre, R
AF Hamaguchi, Kenji
Choi, Minho
Corcoran, Michael F.
Choi, Chul-Sung
Tatematsu, Ken'ichi
Petre, Rob
TI RESOLVING A CLASS I PROTOSTAR BINARY SYSTEM WITH CHANDRA
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE binaries: visual; stars: magnetic fields; stars: pre-main-sequence;
techniques:high angular resolution; X-rays: stars
ID YOUNG STELLAR OBJECTS; AUSTRALIS MOLECULAR CLOUD; X-RAY VARIABILITY;
LOW-MASS STARS; CORONAE-AUSTRALIS; RADIO-EMISSION; CLUSTER; EVOLUTION;
DISCOVERY; CORE
AB Using a subpixel event repositioning technique, we spatially resolved X-ray emission from the infrared double system IRS 5 in the R Corona Australis molecular cloud with similar to 0.8 '' separation. As far as we know, this result-obtained from eight Chandra archival observations between 2000 and 2005-is the first X-ray study of individual sources in a Class I protostar binary system with a projected separation of less than 200 AU. We extracted light curves and spectra of the individual sources using a two-dimensional image-fitting method. IRS 5a at the south, the source that was brighter in the near-infrared, showed three X-ray flares lasting >20 ks, reminiscent of X-ray flares from pre-main-sequence stars, while the northern source (IRS 5b) was quiescent in X-rays in all the observations except for a 2005 August 9 observation with a factor of similar to 2 flux enhancement. In quiescence, these sources showed almost identical X-ray spectra, with N-H similar to 4; 10(22) cm(-2), kT similar to 2 keV, and log L-X similar to 30:2-30: 3 ergs s(-1). IRS 5a showed plasma at temperatures up to kT similar to 5-6 keV during flares, while the column density of IRS 5b increased by a factor of 2 during an observation on 2005 August 9. We discuss the evolutionary stages and variation of the X-ray activity of these sources.
C1 [Hamaguchi, Kenji; Corcoran, Michael F.] NASA, Goddard Space Flight Ctr, Ctr Res & Explorat Space Sci & Technol, Greenbelt, MD 20771 USA.
[Hamaguchi, Kenji; Corcoran, Michael F.] NASA, Goddard Space Flight Ctr, Xray Astrophys Lab, Greenbelt, MD 20771 USA.
[Hamaguchi, Kenji] Univ Maryland Baltimore Cty, Dept Phys, Baltimore, MD 21250 USA.
[Choi, Minho; Choi, Chul-Sung] Korea Astron & Space Sci Inst, Int Ctr Astrophys, Taejon 305348, South Korea.
[Corcoran, Michael F.] Univ Space Res Assoc, Columbia, MD 21044 USA.
[Tatematsu, Ken'ichi] Natl Astron Observ Japan, Mitaka, Tokyo 1818588, Japan.
[Petre, Rob] NASA, Goddard Space Flight Ctr, Astrophys Sci Div, Greenbelt, MD 20771 USA.
RP Hamaguchi, K (reprint author), NASA, Goddard Space Flight Ctr, Ctr Res & Explorat Space Sci & Technol, Greenbelt, MD 20771 USA.
FU NASA Astrobiology Program [CAN 03-OSS-02]; University of Massachusetts;
Analysis Center/California Institute of Technology; National Aeronautics
and Space Administration; National Science Foundation; High Energy
Astrophysics Science Archive Research Center; NASA's Goddard Space
Flight Center
FX This work was performed while K. H. was supported by the NASA
Astrobiology Program under CAN 03-OSS-02. This publication makes use of
data products from the Two Micron All Sky Survey, which is a joint
project of the University of Massachusetts and the Infrared Processing
and Analysis Center/California Institute of Technology, funded by the
National Aeronautics and Space Administration and the National Science
Foundation. This research has made use of data obtained from the High
Energy Astrophysics Science Archive Research Center (HEASARC), provided
by NASA's Goddard Space Flight Center.
NR 43
TC 5
Z9 5
U1 0
U2 2
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD NOV 1
PY 2008
VL 687
IS 1
BP 425
EP 432
DI 10.1086/591544
PG 8
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 364YD
UT WOS:000260370800032
ER
PT J
AU Berghea, CT
Weaver, KA
Colbert, EJM
Roberts, TP
AF Berghea, C. T.
Weaver, K. A.
Colbert, E. J. M.
Roberts, T. P.
TI PARADIGM THAT ULTRALUMINOUS X-RAY SOURCES AS A CLASS REPRESENT ACCRETING
INTERMEDIATE-MASS BLACK HOLES
SO ASTROPHYSICAL JOURNAL
LA English
DT Review
DE accretion; accretion disks; galaxies: general; surveys; X-rays: binaries
ID XMM-NEWTON OBSERVATIONS; POINT-SOURCE POPULATION; HIGH-RESOLUTION
CAMERA; NEARBY SPIRAL GALAXIES; SOURCE NGC-5204 X-1; CHANDRA
OBSERVATIONS; STARBURST GALAXY; SUPERNOVA REMNANT; ANTENNAE GALAXIES;
CIRCINUS GALAXY
AB To test the idea that ultraluminous X-ray sources (ULXs) in external galaxies represent a class of accreting intermediate-mass black holes (IMBHs), we have undertaken a program to identify ULXs and a lower luminosity X-ray comparison sample with the highest quality data in the Chandra archive. We establish as a general property of ULXs that the most X-ray-luminous objects possess the flattest X-ray spectra (in the Chandra bandpass). No prior sample studies have established the general hardening of ULX spectra with luminosity. This hardening occurs at the highest luminosities (absorbed luminosity >= 5 x 10(39) erg s(-1)) and is in line with recent models arguing that ULXs are actually stellar mass black holes. From spectral modeling, we show that the evidence originally taken to mean that ULXs are IMBHs-i.e., the "simple IMBH model''-is nowhere near as compelling when a large sample of ULXs is looked at properly. During the last couple of years, XMM-Newton spectroscopy of ULXs has to a large extent begun to negate the simple IMBH model based on fewer objects. We confirm and expand these results, which validates the XMM-Newton work in a broader sense with independent X-ray data. We find that (1) cool-disk components are present with roughly equal probability and total flux fraction for any given ULX, regardless of luminosity, and (2) cool-disk components extend below the standard ULX luminosity cutoff of 10(39) erg s(-1), down to our sample limit of 10(38.3) erg s(-1). The fact that cool-disk components are not correlated with luminosity damages the argument that cool disks indicate IMBHs in ULXs, for which strong statistical support was never found.
C1 [Berghea, C. T.] Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA.
[Weaver, K. A.] NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA.
[Colbert, E. J. M.] Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA.
[Roberts, T. P.] Univ Durham, Dept Phys, Durham DH1 3LE, England.
RP Berghea, CT (reprint author), Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA.
EM 79berghea@cua.edu; kweaver@milkyway.gsfc.nasa.gov; colbert@jhu.edu;
t.p.roberts@durham.ac.uk
NR 113
TC 44
Z9 45
U1 0
U2 2
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD NOV 1
PY 2008
VL 687
IS 1
BP 471
EP 487
DI 10.1086/591722
PG 17
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 364YD
UT WOS:000260370800037
ER
PT J
AU Altamirano, D
van der Klis, M
Mendez, M
Wijnands, R
Markwardt, C
Swank, J
AF Altamirano, D.
van der Klis, M.
Mendez, M.
Wijnands, R.
Markwardt, C.
Swank, J.
TI DISCOVERY OF KILOHERTZ QUASI-PERIODIC OSCILLATIONS AND STATE TRANSITIONS
IN THE LOW-MASS X-RAY BINARY 1E 1724-3045 (TERZAN 2)
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE accretion, accretion disks; binaries: close; stars: individual (4U
1636-53, 4U 1820-30, 4U 1608-52; 4U 0614+09, 4U 1728 34, Terzan 2, 1E
1724-3045); stars: neutron; X-rays: stars
ID ACCRETING MILLISECOND PULSAR; PROPORTIONAL COUNTER ARRAY;
GLOBULAR-CLUSTER TERZAN-2; ATOLL SOURCE STATES; 4U 1608-52;
NEUTRON-STAR; TIMING FEATURES; AQUILA X-1; SPECTRAL BEHAVIOR; POWER
SPECTRA
AB We have studied the rapid X-ray time variability in 99 pointed observations with the Rossi X-Ray Timing Explorer (RXTE) Proportional Counter Array of the low-mass X-ray binary 1E 1724-3045, including, for the first time, observations of this source in its island and banana states, confirming the atoll nature of this source. We report the discovery of kilohertz quasi-periodic oscillations (kHz QPOs). Although we have five detections of the lower kHz QPO and one detection of the upper kHz QPO, in none of the observations we detect both QPOs simultaneously. By comparing the dependence of the rms amplitude with energy of kHz QPOs in different atoll sources, we conclude that this information cannot be use to unambiguously identify the kilohertz QPOs as was previously thought. We find that Terzan 2 in its different states shows timing behavior similar to that seen in other neutron-star low-mass X-ray binaries (LMXBs). We studied the flux transitions observed between 2004 February and 2005 October and conclude that they are due to changes in the accretion rate.
C1 [Altamirano, D.; van der Klis, M.; Mendez, M.; Wijnands, R.] Univ Amsterdam, Astron Inst Anton Pannekoek, NL-1098 SJ Amsterdam, Netherlands.
[Altamirano, D.; van der Klis, M.; Mendez, M.; Wijnands, R.] Ctr High Energy Astrophys, NL-1098 SJ Amsterdam, Netherlands.
[Mendez, M.] Univ Groningen, Kapteyn Astron Inst, NL-9700 AV Groningen, Netherlands.
[Markwardt, C.; Swank, J.] NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA.
[Markwardt, C.] Univ Maryland, Dept Astron, College Pk, MD 20742 USA.
RP Altamirano, D (reprint author), Univ Amsterdam, Astron Inst Anton Pannekoek, Kruislaan 403, NL-1098 SJ Amsterdam, Netherlands.
EM diego@science.uva.nl
RI Swank, Jean/F-2693-2012; Mendez, Mariano/C-8011-2012
OI Mendez, Mariano/0000-0003-2187-2708
NR 76
TC 9
Z9 9
U1 0
U2 3
PU IOP PUBLISHING LTD
PI BRISTOL
PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND
SN 0004-637X
EI 1538-4357
J9 ASTROPHYS J
JI Astrophys. J.
PD NOV 1
PY 2008
VL 687
IS 1
BP 488
EP 504
DI 10.1086/591304
PG 17
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 364YD
UT WOS:000260370800038
ER
PT J
AU Arzoumanian, Z
Safi-Harb, S
Landecker, TL
Kothes, R
Camilo, F
AF Arzoumanian, Z.
Safi-Harb, S.
Landecker, T. L.
Kothes, R.
Camilo, F.
TI CHANDRA CONFIRMATION OF A PULSAR WIND NEBULA IN DA 495
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE ISM: individual (DA 495, G65.7+1.2); radiation mechanisms: nonthermal;
stars: neutron; supernova remnants; X-rays: ISM
ID X-RAY-EMISSION; CRAB-NEBULA; SUPERNOVA REMNANT; VELA PULSAR;
SIMULATIONS; CONSTRAINTS; EVOLUTION; DA-495; MODEL; SHELL
AB As part of a multiwavelength study of the unusual radio supernova remnant DA 495, we present observations made with the Chandra X-Ray Observatory. Imaging and spectroscopic analysis confirms the previously detected X-ray source at the heart of the annular radio nebula, establishing the radiative properties of two key emission components: a soft unresolved source with a blackbody temperature of 1 MK consistent with a neutron star, surrounded by a non-thermal nebula 4000 in diameter exhibiting a power-law spectrum with photon index Gamma = 1.6 +/- 0.3, typical of a pulsar wind nebula. The implied spin-down luminosity of the neutron star, assuming a conversion efficiency to nebular flux appropriate to Vela-like pulsars, is similar to 10(35) ergs s(-1), again typical of objects a few tens of kiloyears old. Morphologically, the nebular flux is slightly enhanced along a direction, in projection on the sky, independently demonstrated to be of significance in radio polarization observations; we argue that this represents the orientation of the pulsar spin axis. At smaller scales, a narrow X-ray feature is seen extending out 500 from the point source, a distance consistent with the sizes of resolved wind termination shocks around many Vela-like pulsars. Finally, we argue based on synchrotron lifetimes in the estimated nebular magnetic field, that DA 495 represents a rare pulsar wind nebula in which electromagnetic flux makes up a significant part, together with particle flux, of the neutron star's wind, and that this high magnetization factor may account for the nebula's low luminosity.
C1 [Arzoumanian, Z.] CRESST, Greenbelt, MD 20771 USA.
[Arzoumanian, Z.] NASA, Goddard Space Flight Ctr, Xray Astrophys Lab, Greenbelt, MD 20771 USA.
[Arzoumanian, Z.] Univ Space Res Assoc, Columbia, MD 21044 USA.
[Safi-Harb, S.] Univ Manitoba, Dept Phys & Astron, Canada Res Chair, Winnipeg, MB R3T 2N2, Canada.
[Landecker, T. L.; Kothes, R.] Dominion Radio Astrophys Observ, Herzberg Inst Astrophys, Natl Res Council Canada, Penticton, BC V2A 6J9, Canada.
[Kothes, R.] Univ Calgary, Dept Phys & Astron, Calgary, AB T2N 1N4, Canada.
[Camilo, F.] Columbia Univ, Columbia Astrophys Lab, New York, NY 10027 USA.
RP Arzoumanian, Z (reprint author), CRESST, Greenbelt, MD 20771 USA.
FU National Aeronautics and Space Administration [GO3-4092A]; National
Aeronautics and Space Administration ( NASA) [NAS8-03060]; Natural
Sciences and Engineering Research Council (NSERC) of Canada; CGPS is a
Canadian
FX We thank the anonymous referee for a rigorous review that resulted in a
much-improved manuscript. Support for this work was provided by the
National Aeronautics and Space Administration through Chandra Award
Number GO3-4092A issued by the Chandra X-Ray Observatory Center, which
is operated by the Smithsonian Astrophysical Observatory for and on
behalf of the National Aeronautics and Space Administration ( NASA)
under contract NAS8-03060. S. S. H. is supported by the Natural Sciences
and Engineering Research Council (NSERC) of Canada and the Canada
Research Chair program. The CGPS is a Canadian project with
international partners and is supported by NSERC.
NR 40
TC 8
Z9 8
U1 0
U2 3
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD NOV 1
PY 2008
VL 687
IS 1
BP 505
EP 515
DI 10.1086/591654
PG 11
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 364YD
UT WOS:000260370800039
ER
PT J
AU Kothes, R
Landecker, TL
Reich, W
Safi-Harb, S
Arzoumanian, Z
AF Kothes, R.
Landecker, T. L.
Reich, W.
Safi-Harb, S.
Arzoumanian, Z.
TI DA 495: AN AGING PULSAR WIND NEBULA
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE ISM: individual (G65.7+1.2); magnetic fields; polarization; supernova
remnants
ID GALACTIC SUPERNOVA-REMNANTS; RADIO-SOURCES; MAGNETIC-FIELD; CRAB-NEBULA;
SKY SURVEY; PLANE SURVEY; VELA PULSAR; GHZ; CATALOG; EVOLUTION
AB We present a radio continuum study of the pulsar wind nebula (PWN) DA 495 (G65.7+1.2), including images of total intensity and linear polarization from 408 to 10550 MHz based on the Canadian Galactic Plane Survey and observations with the Effelsberg 100 m Radio Telescope. Removal of flux density contributions from a superimposed H II region and from compact extragalactic sources reveals a break in the spectrum of DA 495 at 1.3 GHz, with a spectral index alpha = -0.45 +/- 0:20 below the break and alpha = -0:87 +/- 0.10 above it (S-v alpha V (alpha)). The spectral break is more than 3 times lower in frequency than the lowest break detected in any other PWN. The break in the spectrum is likely the result of synchrotron cooling, and DA 495, at an age of similar to 20,000 yr, may have evolved from an object similar to the Vela X nebula, with a similarly energetic pulsar. We find a magnetic field of similar to 1.3 mG inside the nebula. After correcting for the resulting high internal rotation measure, the magnetic field structure is quite simple, resembling the inner part of a dipole field projected onto the plane of the sky, although a toroidal component is likely also present. The dipole field axis, which should be parallel to the spin axis of the putative pulsar, lies at an angle of similar to 50 degrees east of the north celestial pole and is pointing away from us toward the southwest. The upper limit for the radio surface brightness of any shell-type supernova remnant emission around DA 495 is Sigma(1GHz) similar to 5.4 x 10(-23) Wm(-2) Hz(-1) sr(-1) (assuming a radio spectral index of alpha = -0.5), lower than the faintest shell-type remnant known to date.
C1 [Kothes, R.; Landecker, T. L.] Dominion Radio Astrophys Observ, Herzberg Inst Astrophys, Natl Res Council Canada, Penticton, BC V2A 6J9, Canada.
[Kothes, R.] Univ Calgary, Dept Phys & Astron, Calgary, AB T2N 1N4, Canada.
[Reich, W.] Max Planck Inst Radioastron, D-53121 Bonn, Germany.
[Safi-Harb, S.] Univ Manitoba, Dept Phys & Astron, Canada Res Chair, Winnipeg, MB R3T 2N2, Canada.
[Arzoumanian, Z.] CRESST, Greenbelt, MD 20771 USA.
[Arzoumanian, Z.] NASA, Goddard Space Flight Ctr, Xray Astrophys Lab, Greenbelt, MD 20771 USA.
RP Kothes, R (reprint author), Dominion Radio Astrophys Observ, Herzberg Inst Astrophys, Natl Res Council Canada, POB 248, Penticton, BC V2A 6J9, Canada.
FU Dominion Radio Astrophysical Observatory is a National Facility; Natural
Sciences and Engineering Research Council (NSERC).; Max-Planck-Institut
fur Radioastronomie at Effelsberg; Natural Sciences and Engineering
Research Council; Canadian Research Chairs Program; NASA
[NRA-99-01-LTSA-070]; National Radio Astronomy Observatory (NRAO); Naval
Research Lab; NRAO is operated by Associated Universities, Inc; National
Science Foundation
FX The Dominion Radio Astrophysical Observatory is a National Facility
operated by the National Research Council. The Canadian Galactic Plane
Survey is a Canadian project with international partners and is
supported by the Natural Sciences and Engineering Research Council
(NSERC). This research is based on observations with the 100 m telescope
of the Max-Planck-Institut fur Radioastronomie at Effelsberg. S. S. H.
acknowledges support by the Natural Sciences and Engineering Research
Council and the Canadian Research Chairs Program. Z.A. was supported by
NASA grant NRA-99-01-LTSA-070. The VLSS is being carried out by the
National Radio Astronomy Observatory (NRAO) and the Naval Research Lab.
The NRAO is operated by Associated Universities, Inc., and is a facility
of the National Science Foundation.
NR 58
TC 17
Z9 17
U1 0
U2 3
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD NOV 1
PY 2008
VL 687
IS 1
BP 516
EP 531
DI 10.1086/591653
PG 16
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 364YD
UT WOS:000260370800040
ER
PT J
AU Hendrix, AR
Johnson, RE
AF Hendrix, Amanda R.
Johnson, Robert E.
TI CALLISTO: NEW INSIGHTS FROM GALILEO DISK-RESOLVED UV MEASUREMENTS
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE planets and satellites: general; planets and satellites: individual
(Callisto); ultraviolet: solar system
ID HUBBLE-SPACE-TELESCOPE; MU-M; SATELLITES; IAPETUS; SO2; IRRADIATION;
ATMOSPHERE; EVOLUTION; GANYMEDE; ORGANICS
AB The entire set of observations from the Galileo Ultraviolet Spectrometer (UVS) is analyzed to look for spectral trends across the surface of Callisto, and to probe the spectral shapes in the near-UV. At low resolution, the leading hemisphere is slightly redder than the trailing hemisphere at lambda > 280 nm; this has been interpreted by past researchers to indicate the presence of SO2 on the leading hemisphere. Here we point out that such an "absorption feature'' can be induced when ratioing hemispherical spectra. High-resolution observations are used to detect the presence of an absorption band at high southern latitudes, interpreted to be due to some organic species that is weathered away (carbonized) at lower latitudes. The presence of CO2 in the surface and in the atmosphere of Callisto and the dark nature of the surface suggest that carbon-based species are present across the surface associated with either endogenic or delivered organics. These organics experience chemical modification by UV radiation and are mixed into the regolith by meteoritic bombardment.
C1 [Hendrix, Amanda R.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[Johnson, Robert E.] Univ Virginia, Charlottesville, VA 22904 USA.
RP Hendrix, AR (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM arh@jpl.nasa.gov
FU NASA's Planetary Geology and Geophysics Program
FX The authors acknowledge support from NASA's Planetary Geology and
Geophysics Program and thank Anne Verbiscer for helpful comments on the
manuscript. A. R. H. thanks Karen Simmons for assistance with Galileo
UVS data. This work was performed at the Jet Propulsion Laboratory,
California Institute of Technology, under contract with the National
Aeronautics and Space Administration.
NR 36
TC 10
Z9 10
U1 0
U2 4
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD NOV 1
PY 2008
VL 687
IS 1
BP 706
EP 713
DI 10.1086/591491
PG 8
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 364YD
UT WOS:000260370800054
ER
PT J
AU Griffith, CA
Mckay, CP
Ferri, F
AF Griffith, Caitlin A.
McKay, Christopher P.
Ferri, Francesca
TI TITAN'S TROPICAL STORMS IN AN EVOLVING ATMOSPHERE
SO ASTROPHYSICAL JOURNAL LETTERS
LA English
DT Article
DE convection; methods: analytical; planets and satellites: individual
(Titan); radiative transfer
ID HUYGENS LANDING SITE; TROPOSPHERIC CLOUDS; SOUTH-POLE; METHANE; SURFACE;
ETHANE; ENVIRONMENT; DESCENT; WINDS; PROBE
AB The Huygens probe landed in a damp lake bed fed by fluvial channels, indicative of past rainfall. Such washes, interspersed with vast dunes, are typical of Titan's tropical landscape. Yet, Cassini-Huygens measurements reveal a highly stable tropical atmosphere devoid of deep convective storms, and the formation of washes in dune fields is not understood. Here we examine the effects of seasonal variations in humidity, surface heating, and dynamical forcing on the stability of Titan's troposphere. We find that during the probe landing, the middle troposphere was weakly unstable to convection, consistent with the tenuous cloud detected at 21 km. Yet the tropical atmosphere, at any season, is too stable to produce deep convective storms. Convection in the tropics remains weak and confined to altitudes below similar to 30 km, unless the humidity is increased below 9 km altitude. Solar heating is insufficient to significantly humidify the tropical atmosphere. The large polar lakes are seasonably stable, and the methane column abundance measured by Huygens typical of the tropical atmosphere. Our study indicates the presence of distinct polar and equatorial climates. It also suggests that fluvial features in the tropics do not result from recent seasonal rainstorms, and thereby supports other origins such as geological seepage, cryovolcanism, or a wetter climate in the past.
C1 [Griffith, Caitlin A.] Univ Arizona, Dept Planetary Sci, Tucson, AZ 85719 USA.
[McKay, Christopher P.] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
[Ferri, Francesca] Univ Padua, CISAS, I-35131 Padua, Italy.
RP Griffith, CA (reprint author), Univ Arizona, Dept Planetary Sci, Tucson, AZ 85719 USA.
FU NASA's Planetary Atmospheres Program
FX We thank G. Mitri and S. Rafkin for helpful discussions regarding
Titan's boundary layer, T. Tokano and R. Hueso for constructive comments
on the manuscript, and R. V. Yelle for editorial comments. C. Griffith's
work is supported by NASA's Planetary Atmospheres Program.
NR 36
TC 37
Z9 37
U1 0
U2 3
PU IOP PUBLISHING LTD
PI BRISTOL
PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND
SN 2041-8205
J9 ASTROPHYS J LETT
JI Astrophys. J. Lett.
PD NOV 1
PY 2008
VL 687
IS 1
BP L41
EP L44
DI 10.1086/593117
PG 4
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 398KU
UT WOS:000262731800011
ER
PT J
AU Verth, G
Erdelyi, R
Jess, DB
AF Verth, G.
Erdelyi, R.
Jess, D. B.
TI REFINED MAGNETOSEISMOLOGICAL TECHNIQUE FOR THE SOLAR CORONA
SO ASTROPHYSICAL JOURNAL LETTERS
LA English
DT Article
DE MHD; Sun: corona; Sun: magnetic fields; Sun: oscillations
ID MODE KINK OSCILLATIONS; LOOP OSCILLATIONS; TRANSVERSE OSCILLATIONS;
DENSITY STRATIFICATION; PROMINENCE FIBRILS; AMPLITUDE PROFILE; COOL
LOOPS; TRACE; SEISMOLOGY; TEMPERATURE
AB We present a step-by-step guide of a refined magnetoseismological technique for plasma diagnostics in the Sun's corona. Recently developed MHD wave theory which models a coronal loop as an expanding magnetic flux tube with an arbitrary longitudinal plasma density profile is applied to TRACE observations of fast kink oscillations. The theory predicts that using the observed ratio of the first overtone and fundamental mode to predict the plasma density scale height and not taking account of loop expansion will lead to an overestimation of scale height. For the first time, the size of this correction is quantified directly from observation and for the particular case study presented here, it is found that the overestimation is approximately by a factor of 2.
C1 [Verth, G.; Erdelyi, R.] Univ Sheffield, Solar Phys & Space Plasma Res Ctr, Sheffield S3 7RH, S Yorkshire, England.
[Jess, D. B.] Queens Univ Belfast, Sch Math & Phys, Astrophys Res Ctr, Belfast BT7 1NN, Antrim, North Ireland.
[Jess, D. B.] NASA, Goddard Space Flight Ctr, Solar Phys Lab, Greenbelt, MD 20771 USA.
RP Verth, G (reprint author), Univ Sheffield, Solar Phys & Space Plasma Res Ctr, Hicks Bldg,Hounsfield Rd, Sheffield S3 7RH, S Yorkshire, England.
EM G.Verth@sheffield.ac.uk; robertus@sheffield.ac.uk; djess01@qub.ac.uk
FU Engineering and Physical Sciences Research Council (EPSRC), UK; NSF,
Hungary [K67746]; Northern Ireland Department for Employment and
Learning studentship; NASA Goddard Space Flight Center
FX G. V. is grateful to the Engineering and Physical Sciences Research
Council (EPSRC), UK, for funding received. R. E. acknowledges M. Keray
for patient encouragement and is also grateful to NSF, Hungary (OTKA,
Ref. No. K67746), for financial support. D. B. J. is funded by a
Northern Ireland Department for Employment and Learning studentship. D.
B. J. additionally thanks NASA Goddard Space Flight Center for a CAST
studentship.
NR 33
TC 52
Z9 52
U1 0
U2 1
PU IOP PUBLISHING LTD
PI BRISTOL
PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND
J9 ASTROPHYS J LETT
JI Astrophys. J. Lett.
PD NOV 1
PY 2008
VL 687
IS 1
BP L45
EP L48
DI 10.1086/593184
PG 4
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 398KU
UT WOS:000262731800012
ER
PT J
AU Trouille, L
Barger, AJ
Cowie, LL
Yang, Y
Mushotzky, RF
AF Trouille, L.
Barger, A. J.
Cowie, L. L.
Yang, Y.
Mushotzky, R. F.
TI THE OPTX PROJECT. I. THE FLUX AND REDSHIFT CATALOGS FOR THE CLANS,
CLASXS, AND CDF-N FIELDS
SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
LA English
DT Article
DE cosmology: observations; galaxies: active
ID ACTIVE GALACTIC NUCLEI; X-RAY SURVEY; FRANCE-HAWAII-TELESCOPE;
STAR-FORMING GALAXIES; POINT-SOURCE CATALOG; NUMBER COUNTS; WIDE-FIELD;
LARGE-AREA; PHOTOMETRIC REDSHIFTS; NORTH SURVEY
AB We present the redshift catalogs for the X-ray sources detected in the Chandra Deep Field-North (CDF-N), the Chandra Large Area Synoptic X-ray Survey (CLASXS), and the Chandra Lockman Area North Survey (CLANS). The catalogs for the CDF-N and CLASXS fields include redshifts from previous work, while the redshifts for the CLANS field are all new. For fluxes above 10(-14) ergs cm(-2) s(-1) (2-8 keV) we have redshifts for 76% of the sources. We extend the redshift information for the full sample using photometric redshifts. The goal of the OPTX Project is to use these three surveys, which are among the most spectroscopically complete surveys to date, to analyze the effect of spectral type on the shape and evolution of the X-ray luminosity functions and to compare the optical spectral types with the X-ray spectral properties. We also present the CLANS X-ray catalog. The nine ACIS-I fields cover a solid angle of similar to 0.6 deg(2) and reach fluxes of 7; 10(-16) ergs cm(-2) s(-1) (0.5Y2keV) and 3: 5; 10(-15) ergs cm(-2) s(-1) (2Y8keV). We find a total of 761 X-ray point sources. In addition, we present the optical and infrared photometric catalog for the CLANS X-ray sources, as well as updated optical and infrared photometric catalogs for the X-ray sources in the CLASXS and CDF-N fields. The CLANS and CLASXS surveys bridge the gap between the ultradeep pencil-beam surveys, such as the CDFs, and the shallower, very large-area surveys. As a result, they probe the X-ray sources that contribute the bulk of the 2-8 keV X-ray background and cover the flux range of the observed break in the log N-log S distribution. We construct differential number counts for each individual field and for the full sample.
C1 [Trouille, L.; Barger, A. J.] Univ Wisconsin, Dept Astron, Madison, WI 53706 USA.
[Barger, A. J.] Univ Hawaii, Dept Phys & Astron, Honolulu, HI 96822 USA.
[Barger, A. J.; Cowie, L. L.] Univ Hawaii, Inst Astron, Honolulu, HI 96822 USA.
[Yang, Y.] Univ Illinois, Dept Astron, Urbana, IL 61801 USA.
[Mushotzky, R. F.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
RP Trouille, L (reprint author), Univ Wisconsin, Dept Astron, 475 N Charter St, Madison, WI 53706 USA.
FU NSF [AST 0239425, AST 0708793, AST 0407374, AST 0709356]; Wisconsin
Alumni Research Foundation; David and Lucile Packard Foundation;
University of Wisconsin Research Committee
FX We thank John Silverman for alerting us to the zero-point problems with
the optical data for the CLASXS X-ray sources. We thank the TERAPIX team
for the work they do to produce the CFHT data. L. T. was supported by a
National Science Foundation Graduate Research Fellowship and a Wisconsin
Space Grant Consortium Graduate Fellowship Award during portions of this
work. We also gratefully acknowledge support from NSF grants AST 0239425
and AST 0708793 (A.J.B.) and AST 0407374 and AST 0709356 ( L. L. C.),
the University of Wisconsin Research Committee with funds granted by the
Wisconsin Alumni Research Foundation (A.J.B.), and the David and Lucile
Packard Foundation (A.J.B.). This paper is part of L. T.'s Ph.D. thesis
work at the University of Wisconsin-Madison.
NR 67
TC 46
Z9 46
U1 0
U2 1
PU IOP PUBLISHING LTD
PI BRISTOL
PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND
SN 0067-0049
J9 ASTROPHYS J SUPPL S
JI Astrophys. J. Suppl. Ser.
PD NOV
PY 2008
VL 179
IS 1
BP 1
EP 18
DI 10.1086/591648
PG 18
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 400IV
UT WOS:000262862200001
ER
PT J
AU Luo, B
Bauer, FE
Brandt, WN
Alexander, DM
Lehmer, BD
Schneider, DP
Brusa, M
Comastri, A
Fabian, AC
Finoguenov, A
Gilli, R
Hasinger, G
Hornschemeier, AE
Koekemoer, A
Mainieri, V
Paolillo, M
Rosati, P
Shemmer, O
Silverman, JD
Smail, I
Steffen, AT
Vignali, C
AF Luo, B.
Bauer, F. E.
Brandt, W. N.
Alexander, D. M.
Lehmer, B. D.
Schneider, D. P.
Brusa, M.
Comastri, A.
Fabian, A. C.
Finoguenov, A.
Gilli, R.
Hasinger, G.
Hornschemeier, A. E.
Koekemoer, A.
Mainieri, V.
Paolillo, M.
Rosati, P.
Shemmer, O.
Silverman, J. D.
Smail, I.
Steffen, A. T.
Vignali, C.
TI THE CHANDRA DEEP FIELD-SOUTH SURVEY: 2 Ms SOURCE CATALOGS
SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
LA English
DT Article
DE cosmology: observations; diffuse radiation; galaxies: active; surveys;
X-rays: galaxies
ID X-RAY SOURCES; CCD IMAGING SPECTROMETER; CHARGE-TRANSFER INEFFICIENCY;
MEDIUM-SENSITIVITY SURVEY; POINT-SOURCE CATALOGS; LARGE-SCALE STRUCTURE;
NORTH SURVEY; PHOTOMETRIC REDSHIFTS; CONFIDENCE-LIMITS; NUMBER COUNTS
AB We present point-source catalogs for the approximate to 2Ms exposure of the Chandra Deep Field-South (CDF-S); this is one of the two most sensitive X-ray surveys ever performed. The survey covers an area of approximate to 436 arcmin(2) and reaches on-axis sensitivity limits of approximate to 1: 9; 10(-17) and approximate to 1:3; 10(-16) ergs cm(-2) s(-1) for the 0.5-2.0 and 2-8 keV bands, respectively. Four hundred and sixty-two X-ray point sources are detected in at least one of three X-ray bands that were searched; 135 of these sources are new compared to the previous approximate to 1 Ms CDF-S detections. Source positions are determined using centroid and matched-filter techniques; the median positional uncertainty is approximate to 0.36 ''. The X-ray-to-optical flux ratios of the newly detected sources indicate a variety of source types; approximate to 55% of them appear to be active galactic nuclei, while approximate to 45% appear to be starburst and normal galaxies. In addition to the main Chandra catalog, we provide a supplementary catalog of 86 X-ray sources in the approximate to 2Ms CDF-S footprint that was created by merging the approximate to 250 ks Extended Chandra Deep Field-South with the CDF-S; this approach provides additional sensitivity in the outer portions of the CDF-S. A second supplementary catalog that contains 30 X-ray sources was constructed by matching lower significance X-ray sources to bright optical counterparts (R < 23: 8); the majority of these sources appear to be starburst and normal galaxies. The total number of sources in the main and supplementary catalogs is 578. Optical R-band counterparts and basic optical and infrared photometry are provided for the X-ray sources in the main and supplementary catalogs. We also include existing spectroscopic redshifts for 224 of the X-ray sources. The average backgrounds in the 0.5-2.0 and 2Y8 keV bands are 0.066 and 0.167 counts Ms(-1) pixel(-1), respectively, and the background counts follow Poisson distributions. The effective exposure times and sensitivity limits of the CDF-S are now comparable to those of the approximate to 2Ms Chandra Deep Field-North (CDF-N). We also present cumulative number counts for the main catalog and compare the results to those for the CDF-N. The soft-band number counts for these two fields agree well with each other at fluxes higher than approximate to 2; 10(-16) ergs cm(-2) s(-1), while the CDF-S number counts are up to approximate to 25% smaller than those for the CDF-N at fluxes below approximate to 2; 10(-16) ergs cm(-2) s(-1) in the soft band and approximate to 2; 10(-15) ergs cm(-2) s(-1) in the hard band, suggesting small field-to-field variations.
C1 [Luo, B.; Brandt, W. N.; Schneider, D. P.; Shemmer, O.] Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA.
[Bauer, F. E.] Columbia Univ, Columbia Astrophys Lab, Pupin Labs, New York, NY 10027 USA.
[Alexander, D. M.; Lehmer, B. D.] Univ Durham, Dept Phys, Durham DH1 3LE, England.
[Brusa, M.; Finoguenov, A.; Hasinger, G.] Max Planck Inst Extraterr Phys, D-85748 Garching, Germany.
[Brusa, M.; Finoguenov, A.] Univ Maryland, Baltimore, MD 21250 USA.
[Comastri, A.; Gilli, R.] Osservatorio Astron Bologna, INAF, I-04127 Bologna, Italy.
[Fabian, A. C.] Univ Cambridge, Inst Astron, Cambridge CB3 0HA, England.
[Hornschemeier, A. E.] NASA, Goddard Space Flight Ctr, Lab Xray Astrophys, Greenbelt, MD 20771 USA.
[Koekemoer, A.] Space Telescope Sci Inst, Baltimore, MD 21218 USA.
[Mainieri, V.; Rosati, P.] European So Observ, D-85748 Garching, Germany.
[Paolillo, M.] Univ Naples Federico 2, Dipartimento Sci Fisiche, I-80126 Naples, Italy.
[Silverman, J. D.] ETH, Dept Phys, Inst Astron, CH-8093 Zurich, Switzerland.
[Smail, I.] Univ Durham, Inst Computat Cosmol, Durham DH1 3LE, England.
[Steffen, A. T.] CALTECH, Spitzer Sci Ctr, Pasadena, CA 91125 USA.
[Vignali, C.] Univ Bologna, I-04127 Bologna, Italy.
RP Luo, B (reprint author), Penn State Univ, Dept Astron & Astrophys, 525 Davey Lab, University Pk, PA 16802 USA.
RI Paolillo, Maurizio/J-1733-2012; Vignali, Cristian/J-4974-2012; Smail,
Ian/M-5161-2013; Brandt, William/N-2844-2015; Comastri,
Andrea/O-9543-2015; Gilli, Roberto/P-1110-2015
OI Alexander, David/0000-0002-5896-6313; Koekemoer,
Anton/0000-0002-6610-2048; Brusa, Marcella/0000-0002-5059-6848;
Paolillo, Maurizio/0000-0003-4210-7693; Vignali,
Cristian/0000-0002-8853-9611; Smail, Ian/0000-0003-3037-257X; Brandt,
William/0000-0002-0167-2453; Comastri, Andrea/0000-0003-3451-9970;
Gilli, Roberto/0000-0001-8121-6177
FU NASA through Chandra [SP8-9003A]; Royal Society; Science and Technology
Facilities Council [06-7634, ASIYINAF I/023/05/0, PRIN-MIUR
2006-02-5203]
FX Support for this work was provided by NASA through Chandra Award
SP8-9003A ( B. L., F. E. B., W. N. B., M. B., A. F.) issued by the
Chandra X-ray Observatory Center, which is operated by the Smithsonian
Astrophysical Observatory. We also acknowledge the financial support of
the Royal Society ( D. M. A. and I. R. S.), the Science and Technology
Facilities Council fellowship program ( B. D. L.), NSF grant 06-7634 (
D. P. S.), contract ASIYINAF I/023/05/0 and grant PRIN-MIUR 2006-02-5203
( A. C., R. G., and C. V.). We thank H. D. Tananbaum for allocating the
time for these observations and T. L. Aldcroft, P. Broos, and L. K.
Townsley for helpful discussions.
NR 56
TC 219
Z9 219
U1 0
U2 3
PU IOP PUBLISHING LTD
PI BRISTOL
PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND
SN 0067-0049
J9 ASTROPHYS J SUPPL S
JI Astrophys. J. Suppl. Ser.
PD NOV
PY 2008
VL 179
IS 1
BP 19
EP 36
DI 10.1086/591248
PG 18
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 400IV
UT WOS:000262862200002
ER
PT J
AU Brassington, NJ
Fabbiano, G
Kim, DW
Zezas, A
Zepf, S
Kundu, A
Angelini, L
Davies, RL
Gallagher, J
Kalogera, V
Fragos, T
King, AR
Pellegrini, S
Trinchieri, G
AF Brassington, N. J.
Fabbiano, G.
Kim, D. -W.
Zezas, A.
Zepf, S.
Kundu, A.
Angelini, L.
Davies, R. L.
Gallagher, J.
Kalogera, V.
Fragos, T.
King, A. R.
Pellegrini, S.
Trinchieri, G.
TI DEEP CHANDRA MONITORING OBSERVATIONS OF NGC 3379: CATALOG OF SOURCE
PROPERTIES
SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
LA English
DT Article
DE galaxies: individual (NGC 3379); X-rays: binaries; X-rays: galaxies
ID X-RAY BINARIES; GLOBULAR-CLUSTER SYSTEMS; EARLY-TYPE GALAXIES; ELLIPTIC
GALAXIES; MULTIWAVELENGTH PROJECT; POINT-SOURCE; LUMINOSITY FUNCTION;
CONFIDENCE-LIMITS; SOURCE POPULATION; NEARBY GALAXIES
AB We present the properties of the discrete X-ray sources detected in our monitoring program of the 'typical' elliptical galaxy, NGC 3379, observed with Chandra ACIS-S in five separate pointings, resulting in a co-added exposure of 324 ks. From this deep observation, 132 sources have been detected within the region overlapped by all observations, 98 of which lie within the D(25) ellipse of the galaxy. These 132 sources range in L(X) from 6 x 10(35) erg s(-1) (with 3 sigma upper limit <= 4 x 10(36) erg s(-1)) to similar to 2 x 10(39) erg s(-1), including one source with L(X) > 1 x 10(39) erg s(-1), which has been classified as a ULX. From optical data, 10 X-ray sources have been determined to be coincident with a globular cluster, these sources tend to have high X-ray luminosity, with three of these sources exhibiting L(X) > 1; 1038 erg s(-1). From X-ray source photometry, it has been determined that the majority of the 132 sources that have well constrained colors, have values that are consistent with typical LMXB spectra. In addition to this, a subpopulation of 10 sources has been found to exhibit very hard spectra and it is expected that most of these sources are absorbed background AGN. There are 64 sources in this population that exhibit long-term variability, indicating that they are accreting compact objects. Five of these sources have been identified as transient candidates, with a further 3 possible transients. Spectral variations have also been identified in the majority of the source population, where a diverse range of variability has been identified, indicating that there are many different source classes located within this galaxy.
C1 [Brassington, N. J.; Fabbiano, G.; Kim, D. -W.; Zezas, A.] Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA.
[Zepf, S.; Kundu, A.] Michigan State Univ, Dept Phys & Astron, E Lansing, MI 48824 USA.
[Angelini, L.] NASA, Goddard Space Flight Ctr, Lab Xray Astrophys, Greenbelt, MD 20771 USA.
[Davies, R. L.] Univ Oxford, Subdept Astrophys, Oxford OX1 3RH, England.
[Gallagher, J.] Univ Wisconsin, Dept Astron, Madison, WI 53706 USA.
[Kalogera, V.; Fragos, T.] Northwestern Univ, Dept Phys & Astron, Evanston, IL 60208 USA.
[King, A. R.] Univ Leicester, Theoret Astrophys Grp, Leicester LE1 7RH, Leics, England.
[Pellegrini, S.] Univ Bologna, Dipartimento Astron, I-40127 Bologna, Italy.
[Trinchieri, G.] INAF Osservatorio Astron Brera, I-20121 Milan, Italy.
RP Brassington, NJ (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA.
EM nbrassington@head.cfa.harvard.edu
RI Zezas, Andreas/C-7543-2011
OI Zezas, Andreas/0000-0001-8952-676X
NR 48
TC 36
Z9 36
U1 1
U2 3
PU IOP PUBLISHING LTD
PI BRISTOL
PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND
SN 0067-0049
J9 ASTROPHYS J SUPPL S
JI Astrophys. J. Suppl. Ser.
PD NOV
PY 2008
VL 179
IS 1
BP 142
EP 165
DI 10.1086/591527
PG 24
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 400IV
UT WOS:000262862200008
ER
PT J
AU Contreras, CS
Sahai, R
de Paz, AG
Goodrich, R
AF Sanchez Contreras, C.
Sahai, R.
de Paz, A. Gil
Goodrich, R.
TI ECHELLE LONG-SLIT OPTICAL SPECTROSCOPY OF EVOLVED STARS
SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
LA English
DT Article
DE circumstellar matter; ISM: jets and outflows; planetary nebulae:
general; stars: AGB and post-AGB; stars: mass loss
ID POST-AGB STARS; HIGH-RESOLUTION SPECTROSCOPY; PLANETARY-NEBULA
CANDIDATES; ASYMPTOTIC GIANT BRANCH; PROTOPLANETARY NEBULA;
CIRCUMSTELLAR ENVELOPES; PREPLANETARY NEBULA; IRAS 04296+3429; LINE
EMISSION; DUST SHELL
AB We present echelle long-slit optical spectra of a sample of objects evolving off the asymptotic giant branch (AGB), most of them in the preplanetary nebula (PPN) phase, obtained with the ESI and MIKE spectrographs at the 10 m Keck II and 6.5 m Magellan-I telescopes, respectively. The total wavelength range covered with ESI (MIKE) is similar to 3900-10900 angstrom (similar to 3600-7200 angstrom). In this paper, we focus our analysis mainly on the H alpha profiles. Prominent H alpha emission is detected in half of the objects, most of which show broad H alpha wings (with total widths of up to similar to 4000 km s(-1)). In the majority of the H alpha-emission sources, fast, post-AGB winds are revealed by P-Cygni profiles. In similar to 37% of the objects H alpha is observed in absorption. In almost all cases, the absorption profile is partially filled with emission, leading to complex, structured profiles that are interpreted as an indication of incipient post-AGB mass loss. The rest of the objects (similar to 13%) are H alpha nondetections. We investigate correlations between the H alpha profile and different stellar and envelope parameters. All sources in which H alpha is seen mainly in absorption have F-G type central stars, whereas sources with intense H alpha emission span a larger range of spectral types from O to G, with a relative maximum around B, and also including very late C types. Shocks may be an important excitation/ionization agent of the close stellar surroundings for objects with late type central stars. Sources with pure emission or P Cygni H alpha profiles have larger J - K color excess than objects with H alpha mainly in absorption, which suggests the presence of warm dust near the star in the former. The two classes of profile sources also segregate in the IRAS color-color diagram in away that intense H alpha-emitters have dust grains with a larger range of temperatures. Spectral classification of the central stars in our sample is presented. For a subsample (13 objects), the stellar luminosity has been derived from the analysis of the O I 7771-7775 angstrom infrared triplet. The location in the HR diagram of most of these targets, which represent similar to 30% of the whole sample, is consistent with relatively high final (and, presumably, initial) masses in the range M-f similar to 0: 6-0:9 M-circle dot (M-i similar to 3-8 M-circle dot).
C1 [Sanchez Contreras, C.] CSIC, Inst Estructura Mat, Dept Astrofis Mol & Infrarroja, E-28006 Madrid, Spain.
[Sahai, R.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[de Paz, A. Gil] Univ Complutense Madrid, Dept Astrofis, E-28040 Madrid, Spain.
[Goodrich, R.] WM Keck Observ, Kamuela, HI 96743 USA.
RP Contreras, CS (reprint author), CSIC, Inst Estructura Mat, Dept Astrofis Mol & Infrarroja, Serrano 121, E-28006 Madrid, Spain.
RI Sanchez-Contreras, Carmen/N-3718-2015; Gil de Paz, Armando/J-2874-2016
OI Sanchez-Contreras, Carmen/0000-0002-6341-592X; Gil de Paz,
Armando/0000-0001-6150-2854
NR 93
TC 26
Z9 27
U1 0
U2 3
PU IOP PUBLISHING LTD
PI BRISTOL
PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND
SN 0067-0049
EI 1538-4365
J9 ASTROPHYS J SUPPL S
JI Astrophys. J. Suppl. Ser.
PD NOV
PY 2008
VL 179
IS 1
BP 166
EP 194
PG 29
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 400IV
UT WOS:000262862200009
ER
PT J
AU Henderson, SB
Burkholder, B
Jackson, PL
Brauer, M
Ichoku, C
AF Henderson, Sarah B.
Burkholder, Benjamin
Jackson, Peter L.
Brauer, Michael
Ichoku, Charles
TI Use of MODIS products to simplify and evaluate a forest fire plume
dispersion model for PM10 exposure assessment
SO ATMOSPHERIC ENVIRONMENT
LA English
DT Article
DE Forest fire smoke; Dispersion modeling; MODIS products; Public health
ID AIR-QUALITY; RADIATIVE ENERGY; INDONESIA; EMISSIONS; POLLUTION; HEALTH
AB Plume dispersion models may improve assessment of the health effects associated with forest fire smoke, but they require considerable expertise in atmospheric and fire sciences to initialize and evaluate. Products from MODIS (Moderate Resolution Imaging Spectroradiometer) sensors can simplify the process by providing (1) estimates of fire location, size and emission rates, and (2) data useful for assessing model output. By grouping individual MODIS fire pixels into discrete events we simulated the growth and decay of large fires and estimated their total burned area. Radiative power measurements for each fire pixel were multiplied against a fuel-specific coefficient to estimate particle emission rates. Using the CALMET/CALPUFF package we modeled the dispersion of these particles throughout a 325,000 km 2 area with complex terrain. Moderate agreement (mean r = 0.61) between estimated and measured PM10 concentrations was observed at five of six sites. Because surface measurements are only made at a limited number of locations, we used aerosol optical thickness (AOT) and color imagery product from MODIS for further evaluation. Strong trend association was observed between surface concentrations, model estimates and the AOT measurements. When CALPUFF plume contours were compared to smoke outlines traced from MODIS images we found an average overlap of 50% with better performance under high wind conditions. We conclude that this relatively simple and globally applicable approach can provide a strong foundation for enhanced smoke exposure modeling and public health risk assessment. (c) 2008 Elsevier Ltd. All Fights reserved.
C1 [Jackson, Peter L.] Univ British Columbia, Sch Environm Hlth, Vancouver, BC V6T 1Z3, Canada.
[Ichoku, Charles] Univ Maryland, ESSIC, College Pk, MD 20742 USA.
[Ichoku, Charles] NASA, Goddard Space Flight Ctr, Climate & Radiat Branch, Greenbelt, MD 20771 USA.
RP Henderson, SB (reprint author), Univ British Columbia, Sch Environm Hlth, 3rd Floor,2206 E Mall, Vancouver, BC V6T 1Z3, Canada.
EM sarah.henderson@ubc.ca
RI Ichoku, Charles/E-1857-2012;
OI Ichoku, Charles/0000-0003-3244-4549; Brauer, Michael/0000-0002-9103-9343
FU BC Lung Association; Canadian Institutes of Health Research; Michael
Smith Foundation for Health Research
FX First and foremost we thank Ellen Larcombe who spent many long hours
processing the MODIS data used in these analyses. Thanks also to our
reviewers for helping to focus, clarify and strengthen this work. We
would like to acknowledge the moral and technical support provided by
our colleagues at the British Columbia (BC) Ministry of Forests, BC
Ministry of Environment, NASA, NOAA and SENES Consultants Limited.
Particular thanks go to Cid Praderas for his ongoing support with the
HEG software. Funding for this project is provided by the BC Lung
Association, the Canadian Institutes of Health Research, and the Michael
Smith Foundation for Health Research.
NR 34
TC 10
Z9 10
U1 0
U2 11
PU PERGAMON-ELSEVIER SCIENCE LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
SN 1352-2310
EI 1873-2844
J9 ATMOS ENVIRON
JI Atmos. Environ.
PD NOV
PY 2008
VL 42
IS 36
BP 8524
EP 8532
DI 10.1016/j.atmosenv.2008.05.008
PG 9
WC Environmental Sciences; Meteorology & Atmospheric Sciences
SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences
GA 377QY
UT WOS:000261266900017
ER
PT J
AU Singh, M
Asthana, R
AF Singh, M.
Asthana, R.
TI Characterization of brazed joints of C-C composite to Cu-clad-Molybdenum
SO COMPOSITES SCIENCE AND TECHNOLOGY
LA English
DT Article; Proceedings Paper
CT 5th Asian/Australasian Conference on Composite Materials (ACCM-5)
CY NOV 27-30, 2006
CL Hong Kong, PEOPLES R CHINA
SP Hong Kong Univ Sci & Technol, Nanjing Univ Aeronaut & Astronaut, Hong Kong Polytech Univ, Univ Hong Kong
DE Scanning electron microscopy; Welding/joining; Metals; Hardness testing;
Carbon-carbon composite
ID TO-METAL JOINTS; CARBON-CARBON COMPOSITES; STRAIN-ENERGY RELEASE;
RESIDUAL-STRESSES; INTERLAYERS; TITANIUM; ALUMINA; ALLOYS
AB Carbon-carbon composites with either CVI matrix or resin-derived matrix were joined to copper-clad-molybdenum using two active braze alloys, Cusil-ABA (1.75% Ti) and Ticusil (4.5% Ti). The brazed joints revealed good interfacial bonding, preferential precipitation of Ti at the composite/braze interface, and a tendency toward de-lamination in resin-derived C-C composite due to its low inter-laminar shear strength. Extensive braze penetration of the inter-fiber channels in the CVI C-C composites was observed. The relatively low brazing temperatures (<950 degrees C) precluded melting of the clad layer and restricted the redistribution of alloying elements but led to metallurgically sound composite joints. The Knoop microhardness (HK) distribution across the joint interfaces revealed sharp gradients at the Cu-clad-Mo/braze interface and higher hardness in Ticusil (similar to 85-250 HK) than in Cusil-ABA (similar to 50-150 HK). These C-C/Cu-clad-Mo joints with relatively low thermal resistance may be promising for thermal management applications. (C) 2008 Elsevier Ltd. All rights reserved.
C1 [Asthana, R.] Univ Wisconsin Stout, Dept Engn & Technol, Menomonie, WI 54751 USA.
[Singh, M.] NASA, Ohio Aerosp Inst, Ceram Branch, Glenn Res Ctr, Cleveland, OH 44135 USA.
RP Asthana, R (reprint author), Univ Wisconsin Stout, Dept Engn & Technol, Menomonie, WI 54751 USA.
EM asthanar@uwstout.edu
NR 20
TC 29
Z9 33
U1 3
U2 18
PU ELSEVIER SCI LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND
SN 0266-3538
J9 COMPOS SCI TECHNOL
JI Compos. Sci. Technol.
PD NOV
PY 2008
VL 68
IS 14
SI SI
BP 3010
EP 3019
DI 10.1016/j.compscitech.2008.06.012
PG 10
WC Materials Science, Composites
SC Materials Science
GA 374BM
UT WOS:000261017300026
ER
PT J
AU Tian, Y
Peters-Lidard, CD
Kumar, SV
Geiger, J
Houser, PR
Eastman, JL
Dirmeyer, P
Doty, B
Adams, J
AF Tian, Y.
Peters-Lidard, C. D.
Kumar, S. V.
Geiger, J.
Houser, P. R.
Eastman, J. L.
Dirmeyer, P.
Doty, B.
Adams, J.
TI High-performance land surface modeling with a Linux cluster
SO COMPUTERS & GEOSCIENCES
LA English
DT Article
DE Hydrology modeling; Beowulf cluster; Distributed computing; Parallel
computing; Peer-to-peer network; High-resolution simulation
ID FRAMEWORK; SYSTEM
AB The Land Information System (LIS) was developed at NASA to perform global land surface simulations at a resolution of l-km or finer in real time. Such unprecedented scales and intensity pose many computational challenges. In this article, we demonstrate some of our approaches in high-performance computing with a Linux cluster to meet these challenges and reach our performance goals. These approaches include job partition and a job management system for parallel processing on the cluster, high-performance parallel input/output based on GrADS-DODS (GDS) servers, dynamic load-balancing and distributed data storage techniques, and highly scalable data replication with peer-to-peer (P2P) technology. These techniques work coherently to provide a high-performance land surface modeling system featuring fault tolerance, optimal resource utilization, and high scalability. Examples are given with LIS's high-resolution modeling of surface runoff during 2003 to illustrate LIS's capability to enable new scientific explorations. (C) 2008 Elsevier Ltd. All rights reserved.
C1 [Tian, Y.; Peters-Lidard, C. D.] NASA, Goddard Space Flight Ctr, Hydrol Sci Branch, Greenbelt, MD 20771 USA.
[Tian, Y.; Kumar, S. V.; Eastman, J. L.] Univ Maryland Baltimore Cty, Goddard Earth Sci Technol Ctr, Baltimore, MD 21250 USA.
[Geiger, J.] NASA, Goddard Space Flight Ctr, Informat Syst Div, Greenbelt, MD 20771 USA.
[Houser, P. R.] George Mason Univ, Climate Dynam Program, Calverton, MD 20705 USA.
[Houser, P. R.] George Mason Univ, Ctr Res Environm & Water, Calverton, MD 20705 USA.
[Dirmeyer, P.; Doty, B.; Adams, J.] Ctr Ocean Land Atmosphere Studies, Calverton, MD 20705 USA.
RP Tian, Y (reprint author), NASA, Goddard Space Flight Ctr, Hydrol Sci Branch, Mail Code 614-3, Greenbelt, MD 20771 USA.
EM Yudong.Tian@nasa.gov
RI Peters-Lidard, Christa/E-1429-2012; Houser, Paul/J-9515-2013; Kumar,
Sujay/B-8142-2015; Dirmeyer, Paul/B-6553-2016
OI Peters-Lidard, Christa/0000-0003-1255-2876; Houser,
Paul/0000-0002-2991-0441; Dirmeyer, Paul/0000-0003-3158-1752
FU NASA [ESTO/CT CAN-00-OES01, ESTO/AIST NRA-02-OES-04]
FX We greatly appreciate the assistance from Susan Olden, Luther Lighty,
Joe Wielgosz, Shujia Zhou, Kevin Miller, Meg Larko, Aedan Jenkins, Uttam
Majumder, Nikkia Anderson and Steve Lidard. LIS is a Grand Challenge
investigation funded under NASA ESTO/CT CAN-00-OES01 (Co-Pl's Houser and
Peters-Lidard), with additional support from NASA ESTO/AIST
NRA-02-OES-04 (PI Peters-Lidard). Suggestions and edits from anonymous
reviewers greatly improved this paper.
NR 16
TC 9
Z9 11
U1 0
U2 4
PU PERGAMON-ELSEVIER SCIENCE LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
SN 0098-3004
EI 1873-7803
J9 COMPUT GEOSCI-UK
JI Comput. Geosci.
PD NOV
PY 2008
VL 34
IS 11
BP 1492
EP 1504
DI 10.1016/j.cageo.2007.12.014
PG 13
WC Computer Science, Interdisciplinary Applications; Geosciences,
Multidisciplinary
SC Computer Science; Geology
GA 363SQ
UT WOS:000260287400008
ER
PT J
AU Zhang, Y
Rohde, LH
Emami, K
Hammond, D
Casey, R
Mehta, SK
Jeevarajan, AS
Pierson, DL
Wu, HL
AF Zhang, Ye
Rohde, Larry H.
Emami, Kamal
Hammond, Dianne
Casey, Rachael
Mehta, Satish K.
Jeevarajan, Antony S.
Pierson, Duane L.
Wu, Honglu
TI Suppressed expression of non-DSB repair genes inhibits
gamma-radiation-induced cytogenetic repair and cell cycle arrest
SO DNA REPAIR
LA English
DT Article
DE Gamma radiation; siRNA; Gene expression; DNA repair; Cell cycle
ID ENERGETIC HEAVY-IONS; DOUBLE-STRAND BREAKS; IONIZING-RADIATION;
DNA-DAMAGE; HUMAN-LYMPHOCYTES; ADAPTIVE RESPONSE; HUMAN FIBROBLASTS;
MSH2 DEFICIENCY; UV-IRRADIATION; X-RAYS
AB Changes of gene expression profile are one of the most important biological responses in living cells after ionizing radiation (IR) exposure. Although some studies have shown that genes up-regulated by IR may play important roles in DNA damage repair, the relationship between the regulation of gene expression by IR, particularly genes not known for their roles in double-strand break (DSB) repair, and its impact on cytogenetic responses has not been well studied. The purpose of this study is to identify new roles of IR inducible genes in regulating DSB repair and cell cycle progression. In this study, the expression of 25 genes selected on the basis of their transcriptional changes in response to IR was individually knocked down by small interfering RNA in human fibroblast cells. Frequency of micronuclei (MN) formation and chromosome aberrations were measured to determine efficiency of cytogenetic repair, especially DSB repair. In response to IR, the formation of MN was significantly increased by suppressed expression of five genes: Ku70 (DSB repair pathway), XPA (nucleotide excision repair pathway), RPAI (mismatch repair pathway), RAD17 and RBBP8 (cell cycle control). Knocked-down expression of four genes (MRE11A, RADS1 in the DSB pathway, SESN1, and SUMO1) significantly inhibited cell cycle progression, possibly because of severe impairment of DNA damage repair. Moreover, decreased XPA, p21, or MLH1 expression resulted in both significantly enhanced cell cycle progression and increased yields of chromosome aberrations, indicating that these gene products modulate both cell cycle control and DNA damage repair. Nine of these eleven genes, whose knock-down expression affected cytogenetic repair, were up-regulated in cells exposed to gamma radiation, suggesting that genes transcriptionally modulated by IR were critical to regulate IR-induced biological consequences. Furthermore, eight non-DBS repair genes showed involvement in regulating DSB repair, indicating that successful DSB repair requires both DSB repair mechanisms and non-DSB repair systems, These results reveal that many genes play previously unrecognized roles in multiple DNA repair responses, all of which are required for successful repair of IR-induced damage. (C) 2008 Elsevier B.V. All rights reserved.
C1 [Zhang, Ye] NASA, Lyndon B Johnson Space Ctr, Human Adaptat & Countermeasures Div, Houston, TX 77058 USA.
[Zhang, Ye; Rohde, Larry H.] Univ Houston Clear Lake, Houston, TX 77058 USA.
[Emami, Kamal] Wyle, Houston, TX 77058 USA.
[Hammond, Dianne; Mehta, Satish K.] Enterprise Advisory Serv Inc, Houston, TX 77058 USA.
[Casey, Rachael] Univ Space Res Assoc, Houston, TX 77058 USA.
RP Zhang, Y (reprint author), NASA, Lyndon B Johnson Space Ctr, Human Adaptat & Countermeasures Div, Mail Code SK,2101 NASA Pkwy, Houston, TX 77058 USA.
EM Ye.Zhang-1@nasa.gov
FU NASA
FX We thank Dr. M. Hada for useful discussion. This work was supported by
the NASA Space Radiation Health Program.
NR 47
TC 21
Z9 21
U1 0
U2 4
PU ELSEVIER SCIENCE BV
PI AMSTERDAM
PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS
SN 1568-7864
J9 DNA REPAIR
JI DNA Repair
PD NOV 1
PY 2008
VL 7
IS 11
BP 1835
EP 1845
DI 10.1016/j.dnarep.2008.07.009
PG 11
WC Genetics & Heredity; Toxicology
SC Genetics & Heredity; Toxicology
GA 373CQ
UT WOS:000260949000007
PM 18703169
ER
PT J
AU Van Doornik, DM
Parker, SJ
Millard, SR
Berntson, EA
Moran, P
AF Van Doornik, Donald M.
Parker, Steven J.
Millard, Steven R.
Berntson, Ewann A.
Moran, Paul
TI Multiple paternity is prevalent in Pacific ocean perch (Sebastes alutus)
off the Oregon coast, and is correlated with female size and age
SO ENVIRONMENTAL BIOLOGY OF FISHES
LA English
DT Article
DE Polyandry; Maternal age; Rockfish; Paternity analysis; Mating system;
Microsatellite
ID MICROSATELLITE LOCI; MATING SYSTEMS; ROCKFISH; STOCKS; FISH;
REPRODUCTION; SCORPAENIDAE; POPULATIONS; COMPETITION; WASHINGTON
AB The need to rebuild Pacific ocean perch, Sebastes alutus, populations on the west coast of the United States has precipitated a need to better understand the life history characteristics of this rockfish species. One such characteristic is mating behavior, which has the potential to influence the amount of genetic diversity in a population. We documented and examined the frequency of multiple mating in Pacific ocean perch collected off the Oregon coast using five microsatellite loci. We found that 47 of 66 (71.2%) females examined had broods sired by multiple males. The mean number of sires per brood was 1.92 (SD=0.76) and ranged from 1-4. Polyandrous females were significantly larger and had an older average age than monogamous females. Our results suggest that polyandrous behavior among female Pacific ocean perch off the coast of Oregon is prevalent, is related to female size and age, and should be preserved by maintaining a natural age structure in this population.
C1 [Van Doornik, Donald M.] Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Manchester Res Stn, Manchester, WA 98353 USA.
[Parker, Steven J.] Hatfield Marine Sci Ctr, Oregon Dept Fish & Wildlife, Newport, OR 97365 USA.
[Millard, Steven R.] Willamette Univ, Salem, OR 97301 USA.
[Berntson, Ewann A.; Moran, Paul] NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Seattle, WA 98112 USA.
RP Van Doornik, DM (reprint author), Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Manchester Res Stn, POB 130, Manchester, WA 98353 USA.
EM don.vandoornik@noaa.gov
NR 33
TC 7
Z9 7
U1 0
U2 3
PU SPRINGER
PI NEW YORK
PA 233 SPRING ST, NEW YORK, NY 10013 USA
SN 0378-1909
J9 ENVIRON BIOL FISH
JI Environ. Biol. Fishes
PD NOV
PY 2008
VL 83
IS 3
BP 269
EP 275
DI 10.1007/s10641-008-9331-0
PG 7
WC Ecology; Marine & Freshwater Biology
SC Environmental Sciences & Ecology; Marine & Freshwater Biology
GA 363JE
UT WOS:000260262800004
ER
PT J
AU Hrinda, GA
Nguyen, DT
AF Hrinda, Glenn A.
Nguyen, Duc T.
TI Optimization of stability-constrained geometrically nonlinear shallow
trusses using an arc length sparse method with a strain energy density
approach
SO FINITE ELEMENTS IN ANALYSIS AND DESIGN
LA English
DT Article
DE Optimization; Stability constrained; Geometrically nonlinear; Trusses;
Arc length; Sparse; Strain energy density
ID STRUCTURAL DESIGN; SNAP-THROUGH
AB A technique for the optimization of stability-constrained geometrically nonlinear shallow trusses with snap-through behavior is demonstrated using the arc length method and a strain energy density approach within a discrete finite-element formulation. The optimization method uses an iterative scheme that evaluates the performance of the design variables and then updates them according to a recursive formula that is controlled by the arc length method. A minimum weight design is achieved when a uniform nonlinear strain energy density is found in all members. This minimal condition places the design load just below the critical-limit load that causes snap-through of the structure. The optimization scheme is programmed into a nonlinear finite-element algorithm to find the large strain energy at critical-limit loads. Examples of highly nonlinear trusses that are found in literature are presented to verify the method. Published by Elsevier B.V.
C1 [Hrinda, Glenn A.] NASA, Langley Res Ctr, Hampton, VA 23681 USA.
[Nguyen, Duc T.] Old Dominion Univ, Dept Civil & Environm Engn, Norfolk, VA 23529 USA.
RP Hrinda, GA (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA.
EM glenn.a.hrinda@nasa.gov
NR 18
TC 6
Z9 6
U1 0
U2 7
PU ELSEVIER SCIENCE BV
PI AMSTERDAM
PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS
SN 0168-874X
J9 FINITE ELEM ANAL DES
JI Finite Elem. Anal. Des.
PD NOV
PY 2008
VL 44
IS 15
BP 933
EP 950
DI 10.1016/j.finel.2008.07.004
PG 18
WC Mathematics, Applied; Mechanics
SC Mathematics; Mechanics
GA 366CZ
UT WOS:000260459500005
ER
PT J
AU Milliken, RE
Swayze, GA
Arvidson, RE
Bishop, JL
Clark, RN
Ehlmann, BL
Green, RO
Grotzinger, JP
Morris, RV
Murchie, SL
Mustard, JF
Weitz, C
AF Milliken, R. E.
Swayze, G. A.
Arvidson, R. E.
Bishop, J. L.
Clark, R. N.
Ehlmann, B. L.
Green, R. O.
Grotzinger, J. P.
Morris, R. V.
Murchie, S. L.
Mustard, J. F.
Weitz, C.
TI Opaline silica in young deposits on Mars
SO GEOLOGY
LA English
DT Article
ID MERIDIANI-PLANUM; VALLES MARINERIS; JAROSITE; WATER; DIVERSITY;
MINERALS; GLASSES; HISTORY
AB High spatial and spectral resolution reflectance data acquired by the Mars Reconnaissance Orbiter Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) instrument reveal the presence of H2O- and SiOH-bearing phases on the Martian surface. The spectra are most consistent with opaline silica and glass altered to various degrees, confirming predictions based on geochernicall experiments and models that amorphous silica should be a common weathering product of the basaltic Martian crust. These materials are associated with hydrated Fe sulfates, including H3O-bearing jarosite, and are found in finely stratified deposits exposed on the floor of and on the plains surrounding the Valles Marineris canyon system. Stratigraphic relationships place the formation age of these deposits in the late Hesperian or possibly the Amazonian, implying that aqueous alteration continued to be an important and regionally extensive process on Mars during that time.
C1 [Milliken, R. E.; Green, R. O.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[Swayze, G. A.; Clark, R. N.] US Geol Survey, Denver, CO 80225 USA.
[Arvidson, R. E.] Washington Univ, Dept Earth & Planetary Sci, St Louis, MO 63130 USA.
[Bishop, J. L.] NASA, Ames Res Ctr, SETI Inst, Mountain View, CA 94043 USA.
[Mustard, J. F.] Brown Univ, Dept Geol Sci, Providence, RI 02912 USA.
[Grotzinger, J. P.] CALTECH, Pasadena, CA 91125 USA.
[Morris, R. V.] NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA.
[Murchie, S. L.] Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA.
[Weitz, C.] Planetary Sci Inst, Tucson, AZ 85719 USA.
RP Milliken, RE (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM ralph.milliken@jpl.nasa.gov
RI Murchie, Scott/E-8030-2015
OI Murchie, Scott/0000-0002-1616-8751
NR 29
TC 172
Z9 174
U1 5
U2 33
PU GEOLOGICAL SOC AMER, INC
PI BOULDER
PA PO BOX 9140, BOULDER, CO 80301-9140 USA
SN 0091-7613
EI 1943-2682
J9 GEOLOGY
JI Geology
PD NOV
PY 2008
VL 36
IS 11
BP 847
EP 850
DI 10.1130/G24967A.1
PG 4
WC Geology
SC Geology
GA 370HK
UT WOS:000260753100004
ER
PT J
AU Uritsky, VM
Donovan, E
Klimas, AJ
Spanswick, E
AF Uritsky, V. M.
Donovan, E.
Klimas, A. J.
Spanswick, E.
TI Scale-free and scale-dependent modes of energy release dynamics in the
nighttime magnetosphere
SO GEOPHYSICAL RESEARCH LETTERS
LA English
DT Article
ID SELF-ORGANIZED CRITICALITY; AVALANCHING SYSTEM; MAGNETOTAIL;
RECONNECTION; INDEX
AB Based on a spatiotemporal analysis of POLAR UVI images, we show for the first time that energy, power, area and lifetime probability distributions of electron precipitation events in the nighttime auroral oval have a significant latitudinal dependence. The low-latitude group of the events contains a distinct subpopulation of strong auroral distributions violating the uniform power-law behavior reported in previous publications, while the high latitude group is described by nearly perfect power-law statistics over the entire range of scales studied, in agreement with earlier findings. The results obtained indicate that the inner and outer portions of the plasma sheet may be characterized by substantially different scaling regimes of bursty energy dissipation suggestive of different universality classes and/or driving conditions associated with multiscale turbulence in these regions. Citation: Uritsky, V. M., E. Donovan, A. J. Klimas, and E. Spanswick (2008), Scale-free and scale-dependent modes of energy release dynamics in the nighttime magnetosphere, Geophys. Res. Lett., 35, L21101, doi: 10.1029/2008GL035625.
C1 [Uritsky, V. M.; Donovan, E.; Spanswick, E.] Univ Calgary, Dept Phys & Astron, Calgary, AB T3A 0P4, Canada.
[Klimas, A. J.] NASA, Goddard Space Flight Ctr, UMBC, Greenbelt, MD 20771 USA.
RP Uritsky, VM (reprint author), Univ Calgary, Dept Phys & Astron, SB605,2500 Univ Dr NW, Calgary, AB T3A 0P4, Canada.
EM vuritsky@phas.ucalgary.ca
OI Donovan, Eric/0000-0002-8557-4155
FU NSERC
FX This work was partly supported by NSERC operating grant of EFD. We thank
William Liu for stimulating discussions, Art Richmond for APEX
Conversion algorithms, and George Parks and Daniel Chua for Calibrated
POLAR UVI data.
NR 26
TC 14
Z9 14
U1 0
U2 2
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0094-8276
EI 1944-8007
J9 GEOPHYS RES LETT
JI Geophys. Res. Lett.
PD NOV 1
PY 2008
VL 35
IS 21
AR L21101
DI 10.1029/2008GL035625
PG 5
WC Geosciences, Multidisciplinary
SC Geology
GA 368BZ
UT WOS:000260597600002
ER
PT J
AU Moskovitz, NA
Jedicke, R
Gaidos, E
Willman, M
Nesvorny, D
Fevig, R
Ivezic, Z
AF Moskovitz, Nicholas A.
Jedicke, Robert
Gaidos, Eric
Willman, Mark
Nesvorny, David
Fevig, Ronald
Ivezic, Zeljko
TI The distribution of basaltic asteroids in the Main Belt
SO ICARUS
LA English
DT Article
DE Asteriods; Spectroscopy; Asteroids, composition; Asteroid Vesta
ID DIGITAL SKY SURVEY; V-TYPE ASTEROIDS; SPECTROSCOPIC SURVEY; VESTA
FAMILY; PARENT BODY; ORDINARY CHONDRITES; SECULAR RESONANCES;
IRON-METEORITES; SOLAR-SYSTEM; SPECTROGRAPH
AB We present the observational results of a Survey designed to target and detect asteroids whose photometric colors are similar to those of Vesta family members and thus may be considered as candidates for having a basaltic composition. Fifty basaltic candidates were selected with orbital elements that lie outside of the Vesta dynamical family. Optical and near-infrared spectra were used to assign a taxonomic type to 11 of the 50 candidates. Ten of these were spectroscopically confirmed as V-type asteroids, Suggesting that most of the candidates are basaltic and can be used to constrain the distribution of basaltic material in the Main Belt. Using our catalog of V-type candidates and the Success rate of the survey, we Calculate unbiased size-frequency and semi-major axis distributions of V-type asteroids. These distributions, in addition to an estimate For the total mass of basaltic material, suggest that Vesta was the predominant contributor to the basaltic asteroid inventory of the Main Belt, however scattered planetesimals from the inner Solar System (a < 2.0 AU) and other partially/fully differentiated bodies likely contributed to this inventory. In particular, we infer the presence of basaltic fragments in the vicinity of Asteroid 15 Eunomia, which may be derived from a differentiated parent body in the middle Main Belt (2.5 < a < 2.8). We find no asteroidal evidence for a large number of previously undiscovered basaltic asteroids, which agrees with previous theories suggesting that basaltic fragments from the similar to 100 differentiated parent bodies represented in meteorite collections have been "battered to bits" [Burbine, T.H., Meiborn, A., Binzel, R.P., 1996. Meteorit. Planet. Sci. 31, 607-620]. Published by Elsevier Inc.
C1 [Moskovitz, Nicholas A.; Jedicke, Robert; Willman, Mark] Univ Hawaii, Inst Astron, Honolulu, HI 96822 USA.
[Gaidos, Eric] Univ Hawaii, Dept Geol & Geophys, Honolulu, HI 96822 USA.
[Gaidos, Eric] Univ Hawaii, NASA, Astrobiol Inst, Honolulu, HI 96822 USA.
[Nesvorny, David] SW Res Inst, Dept Space Studies, Boulder, CO 80302 USA.
[Fevig, Ronald] Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA.
[Ivezic, Zeljko] Univ Washington, Dept Astron, Seattle, WA 98195 USA.
RP Moskovitz, NA (reprint author), Univ Hawaii, Inst Astron, 2680 Woodlawn Dr, Honolulu, HI 96822 USA.
EM nmosko@ifa.hawaii.edu
FU NASA GSRP [NNX06AI30H]; NSF planetary astronomy [AST04-07134]; NASA
Astrobiology Institute; .M. Keck Foundation; National Science Foundation
[0506716]
FX Thanks to Greg Wirth for his patience and expert advice as we have
Strived for competency with ESI. We would like to acknowledge the
tremendous help received front Greg Aldering, Rolin Thomas, Yannick
Copin and the rest of the SNIFS team. Thanks to Bobby Bus for helpful
suggestions regarding observing and data reduction. We are grateful to
Richard Binzel and Fernando Roig for their insightful reviews. N.M.
would like to acknowledge the support of NASA GSRP grant NNX06AI30H. RJ.
Would like to acknowledge the support of NSF planetary astronomy grant
AST04-07134. E.G. acknowledges support from the NASA Astrobiology
Institute. Some of the data presented herein were obtained at the W.M.
Keck Observatory, which is operated as a scientific partnership among
the California Institute of Technology, the University of California and
the National Aeronautics and Space Administration. The Observatory was
made possible by the generous financial support of the W.M. Keck
Foundation. Part of the data utilized in this publication were obtained
and made available by the MIT-UH-IRTF joint Campaign for NEO
Reconnaissance. The IRTF is operated by the University of Hawaii under
Cooperative Agreement No. NCC 5-538 with the National Aeronautics and
Space Administration, Office of Space Science, Planetary Astronomy
Program. The MIT component of this work is supported by the National
Science Foundation under Grant No. 0506716. We wish to recognize and
acknowledge the very significant cultural role and reverence that the
summit of Mauna Kea has always had within the indigenous Hawaiian
community. We are most fortunate to have the opportunity to conduct
observations from this mountain.
NR 81
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U1 0
U2 4
PU ACADEMIC PRESS INC ELSEVIER SCIENCE
PI SAN DIEGO
PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA
SN 0019-1035
J9 ICARUS
JI Icarus
PD NOV
PY 2008
VL 198
IS 1
BP 77
EP 90
DI 10.1016/j.icarus.2008.07.006
PG 14
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 367YY
UT WOS:000260589700008
ER
PT J
AU Stolorz, P
Roden, J
Granat, R
AF Stolorz, Paul
Roden, Joe
Granat, Robert
TI Data Mining as a Foundation for Science-Enabling Autonomy
SO IEEE AEROSPACE AND ELECTRONIC SYSTEMS MAGAZINE
LA English
DT Article
AB In-situ exploration by spacecraft and planetary rovers will increasingly require knowledge "on demand" in the future as downlink constraints limit the amount of information that can be transmitted from these platforms back to Earth. Several on-board processing methods have the potential to significantly enhance scientific results in these settings. They include automatic detection of natural satellites of planetary bodies, investigation of possible surface motions on planets and planetary moons, and directed acquisition of scientific data by planetary rovers. The key ingredient in all three cases is the need to process scientific data directly on-board, so that information can be rapidly provided to an automated spacecraft executive and/or to ground-based Principal Investigators (PIs). We discuss, herein, recent developments in data mining technology that were designed initially for ground-based scientific data analysis. We then outline how these ideas can be migrated to on-board platforms to dramatically enhance the scientific capabilities of autonomous spacecraft.
C1 [Stolorz, Paul; Roden, Joe; Granat, Robert] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Stolorz, P (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
NR 2
TC 0
Z9 0
U1 0
U2 2
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA
SN 0885-8985
J9 IEEE AERO EL SYS MAG
JI IEEE Aerosp. Electron. Syst. Mag.
PD NOV
PY 2008
VL 23
IS 11
BP 19
EP 24
DI 10.1109/MAES.2008.4693986
PG 6
WC Engineering, Aerospace; Engineering, Electrical & Electronic
SC Engineering
GA 380LN
UT WOS:000261467300007
ER
PT J
AU Blackmore, L
Rajamanoharan, S
Williams, BC
AF Blackmore, Lars
Rajamanoharan, Senthooran
Williams, Brian C.
TI Active Estimation for Jump Markov Linear Systems
SO IEEE TRANSACTIONS ON AUTOMATIC CONTROL
LA English
DT Article
DE Estimation; fault diagnosis; hybrid systems; switching systems
ID ADAPTIVE ESTIMATION; FAILURE-DETECTION; SIGNAL-DESIGN
AB Jump Markov Linear Systems are convenient models for systems that exhibit both continuous dynamics and discrete mode changes. Estimating the hybrid discrete-continuous state of these systems is important for control and fault detection. Existing solutions for hybrid estimation approximate the belief state by maintaining a subset of the possible discrete mode sequences. This approximation can cause the estimator to lose track of the true mode sequence when the effects of discrete mode changes are subtle.
In this paper, we present a method for active hybrid estimation, where control inputs can be designed to discriminate between possible mode sequences. By probing the system for the purposes of estimation, such a sequence of control inputs can greatly reduce the probability of losing the true mode sequence compared to a nominal control sequence. Furthermore, by using a constrained finite horizon optimization formulation, we are able to guarantee that a given control task is achieved, while optimally detecting the hybrid state.
In order to achieve this, we present three main contributions. First, we develop a method by which a sequence of control inputs is designed in order to discriminate optimally between a finite number of linear dynamic system models. These control inputs minimize a novel, tractable upper bound on the probability of model selection error. Second, we extend this approach to develop an active estimation method for Jump Markov Linear Systems by relating the probability of model selection error to the probability of losing the true mode sequence. Finally, we make this method tractable using a principled pruning technique.
Simulation results show that the new method applied to an aircraft fault detection problem significantly decreases the probability of a hybrid estimator losing the true mode sequence.
C1 [Blackmore, Lars] CALTECH, Jet Prop Lab, NASA, Pasadena, CA 91109 USA.
[Rajamanoharan, Senthooran] Univ Cambridge, Dept Theoret Phys, Cambridge CB2 1TN, England.
[Williams, Brian C.] MIT, Dept Aeronaut & Astronaut, Cambridge, MA 02139 USA.
RP Blackmore, L (reprint author), CALTECH, Jet Prop Lab, NASA, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM lars@jpl.nasa.gov
FU Massachusetts Institute of Technology; NASA [NNA04CK9A]; Jet Propulsion
Laboratory; California Institute of Technology
FX This work was supported by the Massachusetts Institute of Technology,
sponsored by NASA Award NNA04CK9A, and by the Jet Propulsion Laboratory,
California Institute of Technology, under a Contract with the National
Aeronautics and Space Administration. Recommended by Associate Editor H.
Hjaimarsson.
NR 35
TC 32
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U1 0
U2 7
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA
SN 0018-9286
EI 1558-2523
J9 IEEE T AUTOMAT CONTR
JI IEEE Trans. Autom. Control
PD NOV
PY 2008
VL 53
IS 10
BP 2223
EP 2236
DI 10.1109/TAC.2008.2006100
PG 14
WC Automation & Control Systems; Engineering, Electrical & Electronic
SC Automation & Control Systems; Engineering
GA 372KD
UT WOS:000260899600001
ER
PT J
AU Kumar, MJ
Reed, MA
Amaratunga, GAJ
Cohen, GM
Janes, DB
Lieber, CM
Meyyappan, M
Wernersson, LE
Wang, KL
Chau, RS
Kamins, TI
Lundstrom, M
Yu, B
Zhou, CW
AF Kumar, M. Jagadesh
Reed, Mark A.
Amaratunga, Gehan A. J.
Cohen, Guy M.
Janes, David B.
Lieber, Charles M.
Meyyappan, M.
Wernersson, Lars-Erik
Wang, Kang L.
Chau, Robert S.
Kamins, Theodore I.
Lundstrom, Mark
Yu, Bin
Zhou, Chongwu
TI Special Issue on Nanowire Transistors: Modeling, Device Design, and
Technology
SO IEEE TRANSACTIONS ON ELECTRON DEVICES
LA English
DT Editorial Material
C1 [Kumar, M. Jagadesh] Indian Inst Technol, New Delhi 110016, India.
[Reed, Mark A.] Yale Univ, New Haven, CT 06520 USA.
[Amaratunga, Gehan A. J.] Univ Cambridge, Cambridge CB2 1TN, England.
[Cohen, Guy M.] IBM Corp, Thomas J Watson Res Ctr, Yorktown Hts, NY 10598 USA.
[Janes, David B.; Lundstrom, Mark] Purdue Univ, W Lafayette, IN 47907 USA.
[Lieber, Charles M.] Harvard Univ, Cambridge, MA 02138 USA.
[Meyyappan, M.; Yu, Bin] NASA, Ames Res Ctr, Ctr Nanotechnol, Moffett Field, CA 94035 USA.
[Wernersson, Lars-Erik] Lund Univ, S-22100 Lund, Sweden.
[Wang, Kang L.] Univ Calif Los Angeles, Los Angeles, CA 90095 USA.
[Chau, Robert S.] Intel Corp, Santa Clara, CA 95054 USA.
[Kamins, Theodore I.] Hewlett Packard Labs, Bristol BS34 8QZ, Avon, England.
[Zhou, Chongwu] Univ So Calif, Los Angeles, CA 90089 USA.
RP Reed, MA (reprint author), Indian Inst Technol, New Delhi 110016, India.
EM mamidala@iece.org; mark.reed@yale.edu; gajl@cam.ac.uk;
guycohen@us.ibm.com; janes@ecn.purdue.edu; cml@cmliris.harvard.edu;
mmeyyappan@mail.arc.nasa.gov; Lars-Erik.wernersson@ftf.lth.se;
wang@ee.ucla.edu; robert.s.chau@intel.com; kamins@hp.com;
lundstro@purdue.edu; byu@mail.arc.nasa.gov; chongwuz@usc.edu
RI KUMAR, M JAGADESH/I-4264-2012
OI KUMAR, M JAGADESH/0000-0001-6657-1277
NR 0
TC 3
Z9 3
U1 1
U2 18
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA
SN 0018-9383
J9 IEEE T ELECTRON DEV
JI IEEE Trans. Electron Devices
PD NOV
PY 2008
VL 55
IS 11
BP 2813
EP 2819
DI 10.1109/TED.2008.2006781
PG 7
WC Engineering, Electrical & Electronic; Physics, Applied
SC Engineering; Physics
GA 372JX
UT WOS:000260899000001
ER
PT J
AU Sun, XH
Yu, B
Ng, G
Meyyappan, M
Ju, SH
Janes, DB
AF Sun, Xuhui
Yu, Bin
Ng, Garrick
Meyyappan, M.
Ju, Sanghyun
Janes, David B.
TI Germanium Antimonide Phase-Change Nanowires for Memory Applications
SO IEEE TRANSACTIONS ON ELECTRON DEVICES
LA English
DT Article
DE Chalcogenide; Flash memory; nanowire; phase change material (PCM); phase
change memory; random access memory (RAM)
ID GESB FILMS; STORAGE
AB GeSb nanowires (NWs) have been grown using a vapor-liquid-solid approach for the fabrication of electrically operated phase-change random access memory device. The NWs are 40-100 nm in diameter and have approximately 90% Sb for fast crystallization. Memory devices show an on/off resistance ratio of 104, reset programming current of 0.7 mA, and set programming current of 60 nA.
C1 [Sun, Xuhui; Yu, Bin; Ng, Garrick; Meyyappan, M.] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
[Ju, Sanghyun; Janes, David B.] Purdue Univ, Sch Elect & Comp Engn, W Lafayette, IN 47907 USA.
RP Sun, XH (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
EM xsun@arc.nasa.gov; bin.yu@nasa.gov; m.meyyappan@nasa.gov
RI Sun, Xuhui /K-5689-2012
NR 19
TC 21
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U1 0
U2 6
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA
SN 0018-9383
EI 1557-9646
J9 IEEE T ELECTRON DEV
JI IEEE Trans. Electron Devices
PD NOV
PY 2008
VL 55
IS 11
BP 3131
EP 3135
DI 10.1109/TED.2008.2005160
PG 5
WC Engineering, Electrical & Electronic; Physics, Applied
SC Engineering; Physics
GA 372JX
UT WOS:000260899000032
ER
PT J
AU Xie, FQ
Haase, JS
Syndergaard, S
AF Xie, Feiqin
Haase, Jennifer S.
Syndergaard, Stig
TI Profiling the Atmosphere Using the Airborne GPS Radio Occultation
Technique: A Sensitivity Study
SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING
LA English
DT Article
DE Airborne; aircraft; atmospheric measurements; Global Positioning System
(GPS); microwave radio propagation; radio occultation (RO)
ID GLOBAL POSITIONING SYSTEM; EARTHS ATMOSPHERE; NEUTRAL ATMOSPHERE;
INVERSION; CHAMP; VALIDATION; ASSIMILATION; TROPOSPHERE; RECEIVER;
MISSION
AB Global Positioning System (GPS) radio occultation (RO) sounding, with its high vertical resolution temperature and humidity profiling capability, is revolutionizing atmospheric science, particularly through assimilation in numerical weather prediction (NWP) models. Currently, the observations are derived from GPS receivers onboard low Earth orbiting satellites. However, with the current number of satellites, it is difficult to provide dense sounding measurements in a specific region within a limited time period. With a GPS receiver onboard an airplane, the GPS RO technique offers such an opportunity while retaining the high vertical resolution sounding capability. The GNSS Instrument System for Multistatic and Occultation Sensing is currently under development for the National Science Foundation's High-performance Instrumented Airborne Platform for Environmental Research (HIAPER) aircraft. This paper presents a sensitivity analysis of the airborne occultation technique that will be used for the HIAPER system. The results demonstrate an anticipated overall accuracy of better than 0.5% for the retrieved refractivity from the surface to about 1 km below the airplane, where the expected airplane velocity errors of up to 5 mm/s limit the accuracy. The effects on the retrievals due to horizontal variations in atmospheric refractivity are significant, and retrieval errors may reach several percent inside frontal systems when the front is perpendicular to the ray paths and within 200 km of the tangent point. In general, the airborne GPS RO system provides a promising new data source for NWP and targeted observational studies.
C1 [Xie, Feiqin; Haase, Jennifer S.] Purdue Univ, Dept Earth & Atmospher Sci, W Lafayette, IN 47907 USA.
[Syndergaard, Stig] Univ Corp Atmospher Res, COSMIC Project Off, Boulder, CO 80307 USA.
RP Xie, FQ (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM Feiqin.Xie@jpl.nasa.gov; jhaase@purdue.edu; ssy@ucar.edu
RI XIE, FEIQIN/J-4569-2013; Syndergaard, Stig/C-1103-2017;
OI Syndergaard, Stig/0000-0003-3119-2618; Xie, Feiqin/0000-0002-3936-9759
FU National Science Foundation [S05-39696]; National Aeronautics and Space
Administration [521 13970250 NRA 03-OES-02]
FX This work was supported in part by the National Science Foundation under
UCAR Contract S05-39696 and in part by the National Aeronautics and
Space Administration under Grant 521 13970250 NRA 03-OES-02.
NR 47
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U1 1
U2 8
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA
SN 0196-2892
EI 1558-0644
J9 IEEE T GEOSCI REMOTE
JI IEEE Trans. Geosci. Remote Sensing
PD NOV
PY 2008
VL 46
IS 11
BP 3424
EP 3435
DI 10.1109/TGRS.2008.2004713
PN 1
PG 12
WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote
Sensing; Imaging Science & Photographic Technology
SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science
& Photographic Technology
GA 378GL
UT WOS:000261309100007
ER
PT J
AU Tanelli, S
Durden, SL
Im, E
Pak, KS
Reinke, DG
Partain, P
Haynes, JM
Marchand, RT
AF Tanelli, Simone
Durden, Stephen L.
Im, Eastwood
Pak, Kyung S.
Reinke, Dale G.
Partain, Philip
Haynes, John M.
Marchand, Roger T.
TI CloudSat's Cloud Profiling Radar After Two Years in Orbit: Performance,
Calibration, and Processing
SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING
LA English
DT Article
DE A-train; clouds; CloudSat; radar
ID MEASURING MISSION TRMM; PRECIPITATION RADAR; DIELECTRIC-CONSTANT;
CROSS-SECTIONS; SEA-WATER; KU-BAND; SURFACE; OCEAN; MODEL; AIRBORNE
AB The Cloud Profiling Radar, the sole science instrument of the CloudSat Mission, is a 94-GHz nadir-looking radar that measures the power backscattered by hydrometeors (clouds and precipitation) as a function of distance from the radar. This instrument has been acquiring global time series of vertical cloud structures since June 2, 2006. In this paper, an overview of the radar performance and status, to date, is provided together with a description of the basic data products and the surface clutter rejection algorithm introduced for the Release 04 data product.
C1 [Tanelli, Simone; Durden, Stephen L.; Pak, Kyung S.] CALTECH, Jet Prop Lab, Radar Sci & Engn Sect, Pasadena, CA 91109 USA.
[Im, Eastwood] CALTECH, Jet Prop Lab, Earth Sci Technol Res & Adv Concepts Off, Pasadena, CA 91109 USA.
[Partain, Philip] Colorado State Univ, Cooperat Inst Res Atmosphere, CloudSat Data Proc Ctr, Ft Collins, CO 80523 USA.
[Partain, Philip] Sci & Technol Corp, METSAT Div, Ft Collins, CO 80521 USA.
[Marchand, Roger T.] Univ Washington, Joint Inst Study Atmosphere & Oceans, Seattle, WA 98195 USA.
RP Tanelli, S (reprint author), CALTECH, Jet Prop Lab, Radar Sci & Engn Sect, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM simone.tanelli@jpl.nasa.gov
FU NASA Earth Science Pathfinder Program (ESSP)
FX This work was supported by the NASA Earth Science Pathfinder Program
(ESSP).
NR 41
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PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA
SN 0196-2892
J9 IEEE T GEOSCI REMOTE
JI IEEE Trans. Geosci. Remote Sensing
PD NOV
PY 2008
VL 46
IS 11
BP 3560
EP 3573
DI 10.1109/TGRS.2008.2002030
PN 1
PG 14
WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote
Sensing; Imaging Science & Photographic Technology
SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science
& Photographic Technology
GA 378GL
UT WOS:000261309100018
ER
PT J
AU Vogel, RL
Privette, JL
Yu, Y
AF Vogel, Ronald L.
Privette, Jeffrey L.
Yu, Yunyue
TI Creating Proxy VIIRS Data From MODIS: Spectral Transformations for Mid-
and Thermal-Infrared Bands
SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING
LA English
DT Article
DE Infrared; remote sensing; simulation; visible-infrared imager-radiometer
suite (VIIRS)
ID TERRESTRIAL MATERIALS; ATMOSPHERIC WINDOW; EMISSIVITY
AB Prior to the launch of a new satellite, simulated sensor data are often desired to develop and test the new sensors and algorithms. Ideally, these data closely approximate the data that will be collected on-orbit. Although radiative-transfer models can be employed for this purpose, all models have biases, and none can completely mimic the complex heterogeneity of Earth's environmental system. An alternative approach is to derive "proxy" data sets by transforming real observations collected from past or current sensors. Proxy data inherently contain both natural Earth radiation characteristics and sensor noise as the data from the new sensor will. In preparation for the National Polar-orbiting Operational Environmental Satellite System (NPOESS) and NPOESS Preparatory Project missions, we developed a methodology to create proxy data for the mid- and thermal-infrared bands of the Visible-Infrared Imager-Radiometer Suite (VIIRS). Specifically, by combining radiative-transfer modeling and data from NASA's Atmospheric Infrared Sounder (AIRS), we developed spectral transformation equations to convert real Moderate Resolution Imaging Spectroradiometer (MODIS) data into proxy VIIRS data. The functional forms of the equations were determined through regression analysis. Typically, the best spectral transformation equation for a given VIIRS band was a function of multiple MODIS bands, sensor/solar geometry, and surface type. All transformation equations are for clear-sky conditions. Our daytime midinfrared transformation equations have an accuracy that is below the predicted sensor noise for all surface types. Our thermal-infrared equations over land are most accurate for vegetated covers; our ocean equations are accurate for most bands. Validation of this approach with the Advanced Very High Resolution Radiometer suggests that this method may provide higher accuracy proxy data than other methods. Although the advantage in using AIRS is its hyperspectral design, allowing simulation of MODIS and VIIRS bands, its coarse spatial resolution presented a disadvantage in identifying pure land-cover and cloud-free pixels for generating the equation coefficients. Our primary intent with this paper is to offer a methodology for consideration by other sensor teams. Our provisional MODIS-to-VIIRS spectral transformation equations are included for some example surface types.
C1 [Vogel, Ronald L.; Yu, Yunyue] Natl Environm Satellite Data & Informat Serv, IM Syst Grp, NOAA, Ctr Satellite Applicat & Res, Camp Springs, MD 20746 USA.
[Privette, Jeffrey L.] Natl Environm Satellite Data & Informat Serv, NOAA, Natl Climate Data Ctr, Asheville, NC 28801 USA.
NASA, Goddard Space Flight Ctr, Washington, DC USA.
RP Vogel, RL (reprint author), Natl Environm Satellite Data & Informat Serv, IM Syst Grp, NOAA, Ctr Satellite Applicat & Res, Camp Springs, MD 20746 USA.
EM Ronald.Vogel@noaa.gov; Jeff.Privette@noaa.gov; Yunyue.Yu@noaa.gov
RI Privette, Jeffrey/G-7807-2011; Yu, Yunyue/F-5636-2010
OI Privette, Jeffrey/0000-0001-8267-9894;
FU NPOESS Preparatory Project Science Office, National Aeronautics and
Space Administration, Goddard Space Flight Center
FX Manuscript received October 15, 2007; revised February 1, 2008. Current
version published October 30, 2008. This work was Supported by the
NPOESS Preparatory Project Science Office, National Aeronautics and
Space Administration, Goddard Space Flight Center. The manuscript
contents are solely the opinions of the authors and do not constitute a
statement of policy, decision, or position on behalf of NOAA or the U.S.
Government.
NR 16
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U2 4
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA
SN 0196-2892
J9 IEEE T GEOSCI REMOTE
JI IEEE Trans. Geosci. Remote Sensing
PD NOV
PY 2008
VL 46
IS 11
BP 3768
EP 3782
DI 10.1109/TGRS.2008.923320
PN 2
PG 15
WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote
Sensing; Imaging Science & Photographic Technology
SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science
& Photographic Technology
GA 378GJ
UT WOS:000261308900009
ER
PT J
AU Minnis, P
Trepte, QZ
Sun-Mack, S
Chen, Y
Doelling, DR
Young, DF
Spangenberg, DA
Miller, WF
Wielicki, BA
Brown, RR
Gibson, SC
Geier, EB
AF Minnis, Patrick
Trepte, Qing Z.
Sun-Mack, Szedung
Chen, Yan
Doelling, David R.
Young, David F.
Spangenberg, Douglas A.
Miller, Walter F.
Wielicki, Bruce A.
Brown, Ricky R.
Gibson, Sharon C.
Geier, Erika B.
TI Cloud Detection in Nonpolar Regions for CERES Using TRMM VIRS and Terra
and Aqua MODIS Data
SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING
LA English
DT Article
DE Cloud; cloud detection; cloud mask; Clouds and Earth's Radiant Energy
System (CERES); Moderate Resolution Imaging Spectroradiometer (MODIS);
Visible and Infrared Scanner (VIRS)
ID RAINFALL MEASURING MISSION; LAND-SURFACE EMISSIVITY; ENERGY SYSTEM
CERES; METEOROLOGICAL SATELLITE IMAGERS; ON-ORBIT CALIBRATIONS;
CLEAR-SKY; AEROSOL RETRIEVALS; RAPID CALIBRATION; PART I; CHANNELS
AB Objective techniques have been developed to consistently identify cloudy pixels over nonpolar regions in multispectral imager data coincident with measurements taken by the Clouds and Earth's Radiant Energy System (CERES) on the Tropical Rainfall Measuring Mission (TRMM), Terra, and Aqua satellites. The daytime method uses the 0.65-, 3.8-, 10.8-, and 12.0-mu m channels on the TRMM Visible and Infrared Scanner (VIRS) and the Terra and Aqua MODIS. The VIRS and Terra 1.6-mu m channel and the Aqua 1.38- and 2.1-mu m channels are used secondarily. The primary nighttime radiances are from the 3.8-, 10.8-, and 12.0-mu m channels. Significant differences were found between the VIRS and Terra 1.6-mu m and the Terra and Aqua 3.8-mu m channels' calibrations. Cascading threshold tests provide clear or cloudy classifications that are qualified according to confidence levels or other conditions, such as sunglint, that affect the classification. The initial infrared threshold test classifies similar to 43% of the pixels as clouds. The next level seeks consistency in three (two) different channels during daytime (nighttime) and accounts for roughly 40% (25%) of the pixels. The third tier uses refined thresholds to classify remaining pixels. For cloudy pixels, similar to 4% yield no retrieval when analyzed with a cloud retrieval algorithm. The techniques were applied to data between 1998 and 2006 to yield average nonpolar cloud amounts of similar to 0.60. Averages among the platforms differ by < 0.01 and are comparable to surface climatological values, but roughly 0.07 less than means from two other satellite analyses, primarily as a result of missing small subpixel and thin clouds.
C1 [Minnis, Patrick; Doelling, David R.; Young, David F.; Wielicki, Bruce A.; Geier, Erika B.] NASA, Langley Res Ctr, Sci Directorate, Hampton, VA 23681 USA.
[Trepte, Qing Z.; Sun-Mack, Szedung; Chen, Yan; Spangenberg, Douglas A.; Miller, Walter F.; Brown, Ricky R.; Gibson, Sharon C.] Sci Syst & Applicat Inc, Hampton, VA 23666 USA.
RP Minnis, P (reprint author), NASA, Langley Res Ctr, Sci Directorate, Hampton, VA 23681 USA.
RI Minnis, Patrick/G-1902-2010
OI Minnis, Patrick/0000-0002-4733-6148
NR 63
TC 95
Z9 96
U1 0
U2 10
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA
SN 0196-2892
J9 IEEE T GEOSCI REMOTE
JI IEEE Trans. Geosci. Remote Sensing
PD NOV
PY 2008
VL 46
IS 11
BP 3857
EP 3884
DI 10.1109/TGRS.2008.2001351
PN 2
PG 24
WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote
Sensing; Imaging Science & Photographic Technology
SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science
& Photographic Technology
GA 378GJ
UT WOS:000261308900017
ER
PT J
AU Kumar, MJ
Reed, MA
Amaratunga, GAJ
Cohen, GM
Janes, DB
Lieber, CM
Meyyappan, M
Wernersson, LE
Wang, KL
Chau, RS
Kamins, TI
Lundstrom, M
Yu, B
Zhou, CW
AF Kumar, M. Jagadesh
Reed, Mark A.
Amaratunga, Gehan A. J.
Cohen, Guy M.
Janes, David B.
Lieber, Charles M.
Meyyappan, M.
Wernersson, Lars-Erik
Wang, Kang L.
Chau, Robert S.
Kamins, Theodore I.
Lundstrom, Mark
Yu, Bin
Zhou, Chongwu
TI Guest Editorial Special Issue on Nanowire Transistors: Modeling, Device
Design, and Technology
SO IEEE TRANSACTIONS ON NANOTECHNOLOGY
LA English
DT Editorial Material
C1 [Kumar, M. Jagadesh] Indian Inst Technol, New Delhi 110016, India.
[Reed, Mark A.] Yale Univ, New Haven, CT 06520 USA.
[Amaratunga, Gehan A. J.] Univ Cambridge, Cambridge CB2 1TN, England.
[Cohen, Guy M.] IBM Corp, Thomas J Watson Res Ctr, Yorktown Hts, NY 10598 USA.
[Janes, David B.; Lundstrom, Mark] Purdue Univ, W Lafayette, IN 47907 USA.
[Lieber, Charles M.] Harvard Univ, Cambridge, MA 02138 USA.
[Meyyappan, M.; Yu, Bin] NASA, Ames Res Ctr, Ctr Nanotechnol, Moffett Field, CA 94035 USA.
[Wernersson, Lars-Erik] Lund Univ, S-22100 Lund, Sweden.
[Chau, Robert S.] Intel Corp, Santa Clara, CA 95054 USA.
[Kamins, Theodore I.] Hewlett Packard Labs, Bristol BS34 8QZ, Avon, England.
[Zhou, Chongwu] Univ So Calif, Los Angeles, CA 90089 USA.
RP Kumar, MJ (reprint author), Indian Inst Technol, New Delhi 110016, India.
EM mamidala@ieee.org; mark.reed@yale.edu; gajl@cam.ac.uk;
guycohen@us.ibm.com; janes@ecn.purdue.edu; cml@cmliris.harvard.edu;
mmeyyappan@mail.arc.nasa.gov; Lars-Erik.wemersson@ftf.lth.se;
wang@ee.ucla.edu; robert.s.chau@intel.com; kamins@hp.com;
lundstro@purdue.edu; byu@mail.arc.nasa.gov; chongwuz@usc.edu
RI KUMAR, M JAGADESH/I-4264-2012
OI KUMAR, M JAGADESH/0000-0001-6657-1277
NR 0
TC 1
Z9 1
U1 0
U2 8
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA
SN 1536-125X
J9 IEEE T NANOTECHNOL
JI IEEE Trans. Nanotechnol.
PD NOV
PY 2008
VL 7
IS 6
BP 643
EP 650
DI 10.1109/TNANO.2009.2010023
PG 8
WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology;
Materials Science, Multidisciplinary; Physics, Applied
SC Engineering; Science & Technology - Other Topics; Materials Science;
Physics
GA 393HM
UT WOS:000262364400001
ER
PT J
AU Sherrit, S
AF Sherrit, Stewart
TI Complex Material Coefficients and Energy Ratios for Lossy Piezoelectric
Materials
SO IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL
LA English
DT Article
ID DEPENDENCE; VIBRATIONS; CERAMICS; TUBES
AB This correspondence reviews complex material coefficients of piezoelectric materials and their influence on the energy ratios in coupled systems. In lossless systems. it is shown for the length extensional (LE 33) mode in a C-infinity material that there are at least 4 energy ratios that will produce the same coupling value. In addition, in the (LE 33) mode there are at least 2 different experimental conditions to define an energy ratio that produces the same coupling. With the introduction of loss, these 2 experiments and the 4 energy ratios diverge and no longer produce the same coupling. It is shown that the instantaneous ratio of coupled to input energy or the time average of this ratio, if a numerical value is desired, is the appropriate energy ratio in a dissipating system.
C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Sherrit, S (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM ssherrit@jpl.nasa.gov
NR 12
TC 4
Z9 4
U1 0
U2 5
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA
SN 0885-3010
J9 IEEE T ULTRASON FERR
JI IEEE Trans. Ultrason. Ferroelectr. Freq. Control
PD NOV
PY 2008
VL 55
IS 11
BP 2479
EP 2483
DI 10.1109/TUFFC.955
PG 5
WC Acoustics; Engineering, Electrical & Electronic
SC Acoustics; Engineering
GA 372AN
UT WOS:000260873900015
PM 19049927
ER
PT J
AU del Grosso, MF
Mosca, HO
Bozzolo, G
AF del Grosso, M. F.
Mosca, H. O.
Bozzolo, G.
TI Atomistic modeling of Pt additions to NiAl
SO INTERMETALLICS
LA English
DT Article
DE Nickel aluminides, based on NiAl; Thermal properties; Site occupancy;
Simulations, atomistic; Aero-engine components
ID SITE PREFERENCE; ALLOYS; AL; HF; PLATINUM; METAL; FE; ZR; AU; CU
AB Modeling of the behavior of Pt additions to NiAl alloys is performed using a quantum approximate technique suitable for the study of site preference, phase structure, bulk properties and the coefficient of thermal expansion for the B2 NiAlPt phase field. An atom-by-atom analysis yields insight into the quantitative and qualitative changes in these properties as a function of Pt concentration. (C) 2008 Elsevier Ltd. All rights reserved.
C1 [Bozzolo, G.] Ohio Aerosp Inst, Cleveland, OH 44142 USA.
[del Grosso, M. F.; Mosca, H. O.] UA Fis, Comis Nacl Energia Atom, San Martin, Argentina.
[del Grosso, M. F.; Mosca, H. O.] FRG Pacheco, UTN, GCMM, Gral, Pacheco, Argentina.
[Bozzolo, G.] NASA, Glenn Res Ctr, Cleveland, OH 44135 USA.
RP Bozzolo, G (reprint author), Ohio Aerosp Inst, 22800 Cedar Point Rd, Cleveland, OH 44142 USA.
EM guillermobozzolo@oai.org
FU NASA
FX Fruitful discussions with N. Bozzolo are gratefully acknowledged. This
work was partially sponsored by the NASA Fundamental Aeronautics
Program.
NR 19
TC 4
Z9 4
U1 0
U2 5
PU ELSEVIER SCI LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND
SN 0966-9795
J9 INTERMETALLICS
JI Intermetallics
PD NOV-DEC
PY 2008
VL 16
IS 11-12
BP 1305
EP 1309
DI 10.1016/j.intermet.2008.08.006
PG 5
WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy &
Metallurgical Engineering
SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering
GA 381ON
UT WOS:000261545900011
ER
PT J
AU Hauser, K
Bretl, T
Latombe, JC
Harada, K
Wilcox, B
AF Hauser, Kris
Bretl, Timothy
Latombe, Jean-Claude
Harada, Kensuke
Wilcox, Brian
TI Motion Planning for Legged Robots on Varied Terrain
SO INTERNATIONAL JOURNAL OF ROBOTICS RESEARCH
LA English
DT Article; Proceedings Paper
CT 7th International Workshop on Algorithmic Foundations of Robotics
CY JUL 16-18, 2006
CL New York, NY
DE Motion planning; legged robots; humanoids; probabilistic sample-based
planning; motion primitives
ID INVERSE KINEMATICS; CONTACT; OPTIMIZATION; STYLE
AB In this paper we study the quasi-static motion of large legged robots that have many degrees of freedom. While gaited walking may suffice on easy ground, rough and steep terrain requires unique sequences of footsteps and postural adjustments specifically adapted to the terrain's local geometric and physical properties. In this paper we present a planner that computes these motions by combining graph searching to generate a sequence of candidate footfalls with probabilistic sample-based planning to generate continuous motions that reach these footfalls. To improve motion quality, the probabilistic planner derives its sampling strategy from a small set of motion primitives that have been generated offline. The viability of this approach is demonstrated in simulation for the six-legged Lunar vehicle ATHLETE and the humanoid HRP-2 on several example terrains, including one that requires both hand and foot contacts and another that requires rappelling.
C1 [Hauser, Kris; Latombe, Jean-Claude] Stanford Univ, Dept Comp Sci, Stanford, CA 94305 USA.
[Bretl, Timothy] Univ Illinois, Urbana, IL 61801 USA.
[Harada, Kensuke] Natl Inst Adv Ind Sci & Technol, Intelligent Syst Res Inst, Humanoid Res Grp, Tsukuba, Ibaraki 3058568, Japan.
[Wilcox, Brian] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Hauser, K (reprint author), Stanford Univ, Dept Comp Sci, Stanford, CA 94305 USA.
EM khauser@cs.stanford.edu; tbretl@illinois.edu; latombe@cs.stanford.edu;
kensuke.harada@aist.go.jp; Brian.H.Wilcox@jpl.nasa.gov
NR 83
TC 52
Z9 52
U1 0
U2 12
PU SAGE PUBLICATIONS LTD
PI LONDON
PA 1 OLIVERS YARD, 55 CITY ROAD, LONDON EC1Y 1SP, ENGLAND
SN 0278-3649
EI 1741-3176
J9 INT J ROBOT RES
JI Int. J. Robot. Res.
PD NOV
PY 2008
VL 27
IS 11-12
BP 1325
EP 1349
DI 10.1177/0278364908098447
PG 25
WC Robotics
SC Robotics
GA 375EA
UT WOS:000261095700011
ER
PT J
AU Baxley, BT
Williams, D
Consiglio, M
Adams, C
Abbot, T
AF Baxley, Brian T.
Williams, Daniel
Consiglio, Maria
Adams, Cathy
Abbot, Terence
TI Small Aircraft Transportation System, Higher Volume Operations Concept
and Research Summary
SO JOURNAL OF AIRCRAFT
LA English
DT Article; Proceedings Paper
CT AIAA 5th Aviation, Technology, Integration, and Operations Conference
(ATIO)
CY SEP 26-28, 2005
CL Arlington, VA
SP AIAA
AB The ability to conduct concurrent, multiple aircraft operations in poor weather at virtually any airport offers an opportunity to increase the rate of flight operations, an improvement in passenger convenience, and the potential to foster the growth of small airports. The small aircraft transportation system, higher volume operations concept will increase capacity at the 3400 nonradar, nontowered airports in the United States where operations are currently restricted to a "one-in, one-out'' procedural separation during low visibility or ceilings. The concept's key feature is that pilots maintain their own separation from other aircraft using the air-to-air data link and onboard software within the self-controlled area, an area of flight operations established during poor visibility and low ceilings around an airport without Air Traffic Control services. While pilots self-separate within the self-controlled area, an airport management module located at the airport assigns arriving pilots their sequence based on aircraft performance, position, and Air Traffic Control intent. The higher volume operations concept uses distributed decision making and safe procedures designed to minimize pilot and controller workload and integrates with today's Air Traffic Control environment. This paper summarizes the higher volume operations concept, procedures, research, and results, as well as outlines areas in which future higher volume operations research is required.
C1 [Baxley, Brian T.; Williams, Daniel] NASA, Langley Res Ctr, Aviat Operat & Evaluat Branch, Hampton, VA 23681 USA.
[Abbot, Terence] Booz Allen & Hamilton Inc, Mclean, VA 22101 USA.
[Consiglio, Maria; Adams, Cathy] NASA, Langley Res Ctr, Crew Syst Branch, Hampton, VA 23681 USA.
RP Baxley, BT (reprint author), NASA, Langley Res Ctr, Aviat Operat & Evaluat Branch, MS 152, Hampton, VA 23681 USA.
NR 24
TC 2
Z9 2
U1 1
U2 3
PU AMER INST AERONAUT ASTRONAUT
PI RESTON
PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA
SN 0021-8669
J9 J AIRCRAFT
JI J. Aircr.
PD NOV-DEC
PY 2008
VL 45
IS 6
BP 1825
EP 1834
DI 10.2514/1.20493
PG 10
WC Engineering, Aerospace
SC Engineering
GA 383FQ
UT WOS:000261659900001
ER
PT J
AU Edwards, JW
AF Edwards, John W.
TI Calculated Viscous and Scale Effects on Transonic Aeroelasticty
SO JOURNAL OF AIRCRAFT
LA English
DT Article
ID AIRFOIL; FLOW
AB A viscous-inviscid interactive coupling method is used for the computation of unsteady transonic flows. A lag-entrainment integral boundary layer method is used with a transonic small-disturbance potential code to compute the transonic aeroelastic response for two wing flutter models. By varying the modeled length scale, viscous effects may be studied as the Reynolds number per reference chord length varies. Appropriate variation of modeled frequencies and generalized masses then allows comparison of responses for varying scales or Reynolds number. Two wing flutter models are studied: one a 4% thick swept wing and the other a transport aircraft wing. Calculations for both wings show limit cycle oscillation behavior at transonic speeds in the vicinity of minimum flutter speed indices with amplitudes which are affected by Reynolds number.
C1 NASA, Langley Res Ctr, Aeroelast Branch, Hampton, VA 23681 USA.
RP Edwards, JW (reprint author), NASA, Langley Res Ctr, Aeroelast Branch, Hampton, VA 23681 USA.
NR 47
TC 8
Z9 9
U1 0
U2 0
PU AMER INST AERONAUT ASTRONAUT
PI RESTON
PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA
SN 0021-8669
J9 J AIRCRAFT
JI J. Aircr.
PD NOV-DEC
PY 2008
VL 45
IS 6
BP 1863
EP 1871
DI 10.2514/1.30082
PG 9
WC Engineering, Aerospace
SC Engineering
GA 383FQ
UT WOS:000261659900004
ER
PT J
AU An, J
Acar, E
Haftka, RT
Kim, NH
Ifju, PG
Johnson, TF
AF An, Jungeun
Acar, Erdem
Haftka, Raphael T.
Kim, Nam H.
Ifju, Peter G.
Johnson, Theodore F.
TI Being Conservative with a Limited Number of Test Results
SO JOURNAL OF AIRCRAFT
LA English
DT Article; Proceedings Paper
CT AIAA/ASME/ASCE/AHS/ASC 48th Structures, Structural Dynamics, and
Materials Conference/3rd AIAA Multidisciplinary Design Optimization
Specialist Conference
CY APR 23-26, 2007
CL Honolulu, HI
SP Amer Inst Aeronaut & Astronaut, ASME, ASCE, AHS, ASC
ID STRUCTURAL SAFETY
AB In aircraft structural design, failure stresses are obtained from coupon tests and then used to predict failure under combined loads in structural elements. Structural element tests are next used to update the failure envelope for combined loads. It is a common practice to repeat the element tests and then select the lowest test result as a conservative estimate of the mean failure stress. This practice is equivalent to reducing the average test failure stress by a knockdown factor (one that is quite variable). Instead, we propose using the average test result with an explicit knockdown factor obtained from statistical distribution of the test data. We show reductions in the variability of the estimated mean failure stress as well as the likelihood of unconservative estimate. In addition, when the initial distribution or confidence interval of the mean failure stresses is available, we can further decrease the chance of unconservative estimate using Bayesian updating. We demonstrate the gains associated with Bayesian updating when the upper and lower bounds of errors in the analytical predictions are available. Examples with uniform and lognormal distributions of failure stresses compare the lowest-result approach with the two alternatives with the explicit knockdown factor. Both approaches significantly reduce the likelihood of unconservative estimates of the mean failure stress. The average approach reduced this likelihood by about a half and the Bayesian approach by up to an order of magnitude (from 12.5 to 1%). We also examine scenarios in which estimates of error and variability are substantially inaccurate. We show that, even then, the likelihood of unconservalive estimates reduces significantly. Remarkably, an underestimate of variability also results in about a 2% higher average of the estimated mean failure stress. Thus, we are able to simultaneously use higher average failure stress (leading to lower weight) and reduce the likelihood of unconservative estimates.
C1 [An, Jungeun; Acar, Erdem; Haftka, Raphael T.; Kim, Nam H.; Ifju, Peter G.] Univ Florida, Dept Mech & Aerosp Engn, Gainesville, FL 32611 USA.
[Johnson, Theodore F.] NASA, Langley Res Ctr, Hampton, VA 23681 USA.
RP An, J (reprint author), Univ Florida, Dept Mech & Aerosp Engn, Gainesville, FL 32611 USA.
EM jean@ufl.edu; acar@etu.edu.tr; haftka@ufl.edu; nkim@ufl.edu;
ifju@ufl.edu; Theodore.F.Johnson@nasa.gov
RI Acar, Erdem/K-2731-2014
OI Acar, Erdem/0000-0002-3661-5563
NR 10
TC 5
Z9 6
U1 1
U2 1
PU AMER INST AERONAUT ASTRONAUT
PI RESTON
PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA
SN 0021-8669
J9 J AIRCRAFT
JI J. Aircr.
PD NOV-DEC
PY 2008
VL 45
IS 6
BP 1969
EP 1975
DI 10.2514/1.35551
PG 7
WC Engineering, Aerospace
SC Engineering
GA 383FQ
UT WOS:000261659900014
ER
PT J
AU Paielli, RA
AF Paielli, Russell A.
TI Tactical Conflict Resolution Using Vertical Maneuvers in En Route
Airspace
SO JOURNAL OF AIRCRAFT
LA English
DT Article; Proceedings Paper
CT AIAA 8th Aviation Technology, Integration, and Operations Conference
CY SEP 14-19, 2008
CL Anchorage, AK
SP Amer Inst Aeronaut & Astronaut
AB An algorithm is presented far computing vertical resolution maneuvers to resolve imminent air traffic conflicts in which loss of separation could occur within two minutes. Several procedures are used, including rejection of altitude amendments that could cause a conflict, temporary altitudes, step attitudes, and critical-level-off confirmation. These methods are tested on archived data from 100 actual operational errors (loss of separation due to controller error), which tend to be more difficult to detect and resolve than routine conflicts that get resolved successfully. Successful resolution wits achieved in simulation for 84 of them using vertical maneuvers only. Augmented attitude amendments are then added to the input files to simulate altitude amendments that should have been entered by the controller but were not, or to correct amendments to make them consistent with the pilot's understanding. The number of successful resolutions increased to 94 of the 100 cases. The reasons for the failures are discussed.
C1 NASA, Ames Res Ctr, Aviat Syst Div, Moffett Field, CA 94035 USA.
RP Paielli, RA (reprint author), NASA, Ames Res Ctr, Aviat Syst Div, Mail Stop 210-10, Moffett Field, CA 94035 USA.
EM Russ.Paielli@nasa.gov
NR 10
TC 4
Z9 4
U1 0
U2 4
PU AMER INST AERONAUT ASTRONAUT
PI RESTON
PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA
SN 0021-8669
J9 J AIRCRAFT
JI J. Aircr.
PD NOV-DEC
PY 2008
VL 45
IS 6
BP 2111
EP 2119
DI 10.2514/1.39427
PG 9
WC Engineering, Aerospace
SC Engineering
GA 383FQ
UT WOS:000261659900028
ER
PT J
AU Moody, EG
King, MD
Schaaf, CB
Platnick, S
AF Moody, Eric G.
King, Michael D.
Schaaf, Crystal B.
Platnick, Steven
TI MODIS-Derived Spatially Complete Surface Albedo Products: Spatial and
Temporal Pixel Distribution and Zonal Averages
SO JOURNAL OF APPLIED METEOROLOGY AND CLIMATOLOGY
LA English
DT Article
ID REFLECTANCE DISTRIBUTION FUNCTION; AEROSOL PROPERTIES; WATER-VAPOR;
LAND; PHENOLOGY; CLOUD; RETRIEVALS; MODEL; VARIABILITY; ASSESSMENTS
AB Five years (2000-04) of spatially complete snow-free land surface albedo data have been produced using high-quality-flagged diffuse bihemispherical (white sky) and direct-beam directional hemispherical (black sky) land surface albedo data derived from observations taken by the Moderate-Resolution Imaging Spectroradiometer (MODIS) instrument aboard the NASA Terra satellite platform (MOD43B3, collection 4). In addition, a spatially complete snow-free aggregate albedo climatological product was generated. These spatially complete products were prepared using an ecosystem-dependent temporal interpolation technique that retrieves missing data within 3%-8% error. These datasets have already been integrated into research and operational projects that require snow-free land surface albedo. As such, this paper provides details regarding the spatial and temporal distribution of the filled versus the original MOD43B3 data. The paper also explores the intra- and interannual variation in the 5-yr data record and provides a qualitative comparison of zonal averages and annual cycles of the filled versus the original MOD43B3 data. The analyses emphasize the data's inter- and intraannual variation and show that the filled data exhibit large- and small-scale phenological behavior that is qualitatively similar to that of the original MOD43B3. These analyses thereby serve to showcase the inherent spectral, spatial, and temporal variability in the MOD43B3 data as well as the ability of the fill technique to preserve these unique regional and pixel-level phenological characteristics.
C1 [Moody, Eric G.] RS Informat Syst Inc, Lanham, MD USA.
[King, Michael D.; Platnick, Steven] NASA, Goddard Space Flight Ctr, Div Earth Sci, Greenbelt, MD 20771 USA.
[Schaaf, Crystal B.] Boston Univ, Dept Geog, Ctr Remote Sensing, Boston, MA 02215 USA.
RP Moody, EG (reprint author), Wyle Informat Syst, 1651 Old Meadow Rd, Mclean, VA 22102 USA.
EM eric.g.moody@gmail.com
RI King, Michael/C-7153-2011; Platnick, Steven/J-9982-2014
OI King, Michael/0000-0003-2645-7298; Platnick, Steven/0000-0003-3964-3567
FU NASA [621-30-H4, NAS531369]
FX The research reported in this article was supported by the MODIS Science
Team under NASA Contract 621-30-H4 to Goddard Space Flight Center (EGM,
MDK, SP) and NASA Contract NAS531369 to Boston University (CBS). The
authors express their appreciation to Dr. Bernard Pinty, European
Commission Joint Research Centre, for insightful suggestions to clarify
this work and to Dr. Lahouari Bounoua, NASA Goddard Space Flight Center,
for providing valuable insight into modeling-community requirements and
for reviewing the methods used in this work.
NR 38
TC 46
Z9 48
U1 1
U2 9
PU AMER METEOROLOGICAL SOC
PI BOSTON
PA 45 BEACON ST, BOSTON, MA 02108-3693 USA
SN 1558-8424
J9 J APPL METEOROL CLIM
JI J. Appl. Meteorol. Climatol.
PD NOV
PY 2008
VL 47
IS 11
BP 2879
EP 2894
DI 10.1175/2008JAMC1795.1
PG 16
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 374VR
UT WOS:000261072300009
ER
PT J
AU Nasiri, SL
Kahn, BH
AF Nasiri, Shaima L.
Kahn, Brian H.
TI Limitations of Bispectral Infrared Cloud Phase Determination and
Potential for Improvement
SO JOURNAL OF APPLIED METEOROLOGY AND CLIMATOLOGY
LA English
DT Article
ID RADIATION BUDGET EXPERIMENT; AIRBORNE SIMULATOR IMAGERY;
THERMODYNAMIC-PHASE; OPTICAL-CONSTANTS; TRANSFER MODEL; WATER-VAPOR;
THIN CIRRUS; MU-M; MODIS; CLIMATE
AB Determining cloud thermodynamic phase using infrared satellite observations typically requires a priori assumptions about relationships between cloud phase and cloud temperature. In this study, limitations of an approach using two infrared channels with moderate spectral resolutions are demonstrated, as well as the potential for improvement using channels with higher spectral resolution. The Moderate Resolution Imaging Spectroradiometer (MODIS) instrument uses a bispectral infrared cloud phase determination algorithm. MODIS observations during January 2005 show that approximately 23% of cloudy pixels are classified as mixed or unknown cloud phase; this increases to 78% when only cloud-top temperatures between 250 and 265 K are considered. Radiative transfer simulations show that the bispectral algorithm has limited ability to discriminate between water and ice clouds in this temperature range. There is also the potential for thin ice clouds at colder temperatures to be misclassified as water clouds. In addition, sensitivities to cloud particle size and cloud height can be larger than sensitivities to cloud phase. Simulations suggest that phase sensitivity may be higher with hyperspectral observations such as those from the Atmospheric Infrared Sounder (AIRS). The AIRS brightness temperature differences between channels at 8.1 and 10.4 mu m show phase sensitivities of at least 0.5 K, regardless of cloud particle size, cloud-top temperature, or cloud height. They also demonstrate reduced sensitivity to atmospheric temperature and water vapor variability. The reduced sensitivity of AIRS radiances to these physical quantities shows that hyperspectral sounders will serve an important role in refining estimates of cloud phase.
C1 [Nasiri, Shaima L.] Texas A&M Univ, Dept Atmospher Sci, College Stn, TX 77843 USA.
[Kahn, Brian H.] CALTECH, Jet Prop Lab, Pasadena, CA USA.
RP Nasiri, SL (reprint author), Texas A&M Univ, Dept Atmospher Sci, 3150 TAMU, College Stn, TX 77843 USA.
EM snasiri@tamu.edu
RI Nasiri, Shaima/C-8044-2011
FU NASA Postdoctoral Program; NASA Radiation Sciences Program
FX Author Kahn was funded by the NASA Postdoctoral Program during this
study and acknowledges the support of the NASA Radiation Sciences
Program directed by H. Maring. The authors thank Dr. David Kratz for
providing correlated k-distribution routines for MODIS and the AIRS and
MODIS team members for assistance and public release of data products,
as well as information regarding algorithm thresholds. MODIS data were
obtained through the level-1 and Atmosphere Archive and Distribution
System (LAADS; http://ladsweb.nascom.nasa.gov/). AIRS data were obtained
through the Goddard Earth Sciences Data and Information Services Center
(http://daac.gsfc.nasa.gov). A portion of this work was performed at the
Jet Propulsion Laboratory, California Institute of Technology, under
contract with NASA.
NR 57
TC 29
Z9 30
U1 0
U2 7
PU AMER METEOROLOGICAL SOC
PI BOSTON
PA 45 BEACON ST, BOSTON, MA 02108-3693 USA
SN 1558-8424
EI 1558-8432
J9 J APPL METEOROL CLIM
JI J. Appl. Meteorol. Climatol.
PD NOV
PY 2008
VL 47
IS 11
BP 2895
EP 2910
DI 10.1175/2008JAMC1879.1
PG 16
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 374VR
UT WOS:000261072300010
ER
PT J
AU Silberstein, DS
Wolff, DB
Marks, DA
AF Silberstein, David S.
Wolff, David B.
Marks, David A.
TI Ground Clutter as a Monitor of Radar Stability at Kwajalein, RMI
SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY
LA English
DT Article
ID MEASURING MISSION TRMM; VALIDATION; SATELLITE
AB There are many applications in which the absolute and day-to-day calibrations of radar sensitivity are necessary. This is particularly so in the case of quantitative radar measurements of precipitation. While fine calibrations may be made periodically by a variety of techniques such as the use of antenna ranges, standard targets, and solar radiation, knowledge of variations that occur between such checks is required to maintain the accuracy of the data. This paper presents a method for this purpose using the radar on Kwajalein Atoll to provide a baseline calibration for the control of measurements of rainfall made by the Tropical Rainfall Measuring Mission (TRMM). The method uses echoes from a multiplicity of ground targets. The daily average clutter echoes at the lowest elevation scan have been found to be remarkably stable from hour to hour, day to day, and month to month within better than +/- 1 dB. They vary significantly only after either deliberate system modifications, equipment failure, or other unknown causes. A cumulative distribution function (CDF) of combined precipitation and clutter reflectivity (Ze in dBZ) is obtained on a daily basis, regardless of whether or not rain occurs over the clutter areas. The technique performs successfully if the average daily area mean precipitation echoes (over the area of the clutter echoes) do not exceed 45 dBZ, a condition that is satisfied in most locales. In comparison, reflectivities associated with the most intense clutter echoes can approach 70 dBZ. Thus, the level at which the CDF reaches 95% is affected only by the clutter and reflects variations only in the radar sensitivity. Daily calculations of the CDFs have recently been made beginning with August 1999 data and are used to correct 7.5 yr of measurements, thus enhancing the integrity of the global record of precipitation observed by TRMM. The method is robust and may be applicable to other ground-based radars.
C1 [Silberstein, David S.] NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA.
[Silberstein, David S.; Wolff, David B.; Marks, David A.] Sci Syst & Applicat Inc, Lanham, MD USA.
RP Silberstein, DS (reprint author), NASA, Goddard Space Flight Ctr, Atmospheres Lab, Code 613, Greenbelt, MD 20771 USA.
EM david.s.silberstein@nasa.gov
RI Wolff, David/H-5502-2012
FU NASA [NNG07EJ50C]
FX This study was funded by NASA Grant NNG07EJ50C. The authors thank Dr.
Ramesh Kakar (NASA Headquarters), Dr. Robert Adler (TRMM project
scientist), and Mr. Richard Lawrence (chief, TRMM Satellite Validation
Office) for their guidance and support of this effort. We are grateful
to Dr. Merrill Skolnik for discussions of ground clutter, to Mr. Bartie
Kelley for developing the suite of routines in the Radar Software
Library (RSL in IDL) used in this study, and the support of David
Makofski and Marcella Shupp. We also acknowledge the valuable comments
of the reviewers.
NR 10
TC 22
Z9 23
U1 0
U2 3
PU AMER METEOROLOGICAL SOC
PI BOSTON
PA 45 BEACON ST, BOSTON, MA 02108-3693 USA
SN 0739-0572
J9 J ATMOS OCEAN TECH
JI J. Atmos. Ocean. Technol.
PD NOV
PY 2008
VL 25
IS 11
BP 2037
EP 2045
DI 10.1175/2008JTECHA1063.1
PG 9
WC Engineering, Ocean; Meteorology & Atmospheric Sciences
SC Engineering; Meteorology & Atmospheric Sciences
GA 375IR
UT WOS:000261107900011
ER
PT J
AU Li, ZJ
Chao, Y
Mcwilliams, JC
Ide, K
AF Li, Zhijin
Chao, Yi
Mcwilliams, James C.
Ide, Kayo
TI A Three-Dimensional Variational Data Assimilation Scheme for the
Regional Ocean Modeling System
SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY
LA English
DT Article
ID RANGE FORECAST ERRORS; KALMAN FILTER; STATISTICAL STRUCTURE; ECMWF
IMPLEMENTATION; CIRCULATION MODEL; TROPICAL PACIFIC; RADIOSONDE DATA;
PART II; COVARIANCES; 4D-VAR
AB A three-dimensional variational data assimilation (3DVAR) scheme has been developed within the framework of the Regional Ocean Modeling System (ROMS). This ROMS3DVAR enables the capability of predicting meso-to small-scale variations with temporal scales from hours to days in coastal oceans. To cope with particular difficulties that result from complex coastlines and bottom topography, unbalanced flows, and sparse observations, ROMS3DVAR includes novel strategies. These strategies include the implementation of three-dimensional anisotropic and inhomogeneous error correlations based on a Kronecker product, application of particular weak dynamic constraints, and implementation of efficient and reliable algorithms for minimizing the cost function. The formulation of ROMS3DVAR is presented here, and its implementation off the West Coast is currently under way.
C1 [Li, Zhijin; Chao, Yi] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[Mcwilliams, James C.; Ide, Kayo] Univ Calif Los Angeles, Dept Atmospher & Ocean Sci, Inst Geophys & Planetary Phys, Los Angeles, CA USA.
RP Li, ZJ (reprint author), CALTECH, Jet Prop Lab, M-S 300-323,4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM zhijin.li@jpl.nasa.gov
NR 54
TC 49
Z9 51
U1 0
U2 11
PU AMER METEOROLOGICAL SOC
PI BOSTON
PA 45 BEACON ST, BOSTON, MA 02108-3693 USA
SN 0739-0572
J9 J ATMOS OCEAN TECH
JI J. Atmos. Ocean. Technol.
PD NOV
PY 2008
VL 25
IS 11
BP 2074
EP 2090
DI 10.1175/2008JTECHO594.1
PG 17
WC Engineering, Ocean; Meteorology & Atmospheric Sciences
SC Engineering; Meteorology & Atmospheric Sciences
GA 375IR
UT WOS:000261107900014
ER
PT J
AU Vassiliadis, D
AF Vassiliadis, D.
TI Response of the radiation belt electron flux to the solar wind velocity:
Parameterization by radial distance and energy
SO JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS
LA English
DT Article; Proceedings Paper
CT AGU Fall Meeting 2006
CY DEC 11-15, 2006
CL San Francisco, CA
DE Radiation belts; Energetic particles; Impulse response function; Space
weather; Nonlinear models
ID RELATIVISTIC ELECTRONS; INNER MAGNETOSPHERE; WAVE POWER; PREDICTION;
DEPENDENCE; DYNAMICS; STORMS; SPEED; POLAR
AB The solar wind velocity is the primary driver of the electron flux variability in Earth's radiation belts. The response of the logarithmic flux ("log-flux") to this driver has been determined at the geosynchronous orbit and at a fixed energy [Baker, D.N., McPherron, R-L, Cayton, TE., Klebesadel, R.W., 1990. Linear prediction filter analysis of relativistic electron properties at 6.6 RE. journal of Geophysical Research 95(A9), 15,133-15,140) and as a function of L shell and fixed energy [Vassiliadis, D.. Klimas, A.J., Kanekal, S.G., Baker, D.N., Weigel, R.S., 2002. Long-term average, solar-cycle, and seasonal response of magnetospheric energetic electrons to the solar wind speed. journal of Geophysical Research 107, doi:10.1029/2001JA000506). In this paper we generalize the response model as a function of particle energy (0.8-6.4 MeV) using POLAR HIST measurements. All three response peaks identified earlier figure prominently in the high-altitude POLAR measurements. The positive response around the geosynchronous orbit is peak P, (tau = 2 +/- 1 d: L = 5.8 +/- 0.5; E = 0.8-6.4 MeV), associated with high-speed, low-density streams and the ULF wave activity they produce. Deeper in the magnetosphere, the response is dominated by a positive peak P(0) (0 +/- 1 d; 2.9 +/- 0.5R(E): 0.8-1.1 MeV), of a shorter duration and producing lower-energy electrons. The P(0) response occurs during the passage of geoeffective structures containing high IMF and high-density parts, such as ICMEs and other mass ejecta. Finally, the negative peak V(1) (0 +/- 0.5 d; 5.7 +/- 0.5R(E): 0.8-6.4 MeV) is associated with the "D(st) effect" or the quasiadiabatic transport produced by ring-current intensifications. As energies increase, the P(1) and V(1) peaks appear at lower L, while the D,, effect becomes more pronounced in the region L < 3. The P(0) effectively disappears for E > 1.6 MeV because of low statistics, although it is evident in individual events. The continuity of the response across radial and energy scales supports the earlier hypothesis that each of the three modes corresponds to a qualitatively different type of large-scale electron acceleration and transport. (C) 2008 Elsevier Ltd. All rights reserved.
C1 [Vassiliadis, D.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
[Vassiliadis, D.] George Mason Univ, Dept Computat & Data Sci, Fairfax, VA 22030 USA.
RP Vassiliadis, D (reprint author), W Virginia Univ, Dept Phys, Hodges Hall Box 6315, Morgantown, WV 26506 USA.
EM Dimitris.Vassiliadis@mail.wvu.edu
NR 30
TC 2
Z9 2
U1 1
U2 3
PU PERGAMON-ELSEVIER SCIENCE LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
SN 1364-6826
J9 J ATMOS SOL-TERR PHY
JI J. Atmos. Sol.-Terr. Phys.
PD NOV
PY 2008
VL 70
IS 14
SI SI
BP 1810
EP 1828
DI 10.1016/j.jastp.2008.05.019
PG 19
WC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences
SC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences
GA 381LX
UT WOS:000261538700012
ER
PT J
AU Wijffels, SE
Willis, J
Domingues, CM
Barker, P
White, NJ
Gronell, A
Ridgway, K
Church, JA
AF Wijffels, Susan E.
Willis, Josh
Domingues, Catia M.
Barker, Paul
White, Neil J.
Gronell, Ann
Ridgway, Ken
Church, John A.
TI Changing Expendable Bathythermograph Fall Rates and Their Impact on
Estimates of Thermosteric Sea Level Rise
SO JOURNAL OF CLIMATE
LA English
DT Article
ID WEIGHTED LEAST-SQUARES; OCEAN; XBT; TEMPERATURE; PROFILES; QUALITY;
WATERS
AB A time-varying warm bias in the global XBT data archive is demonstrated to be largely due to changes in the fall rate of XBT probes likely associated with small manufacturing changes at the factory. Deep-reaching XBTs have a different fall rate history than shallow XBTs. Fall rates were fasterst in the early 1970s, reached a minimum between 1975 and 1985, reached another maximum in the late 1980s and early 1990s, and have been declining since. Field XBT/CTD intercomparisons and a pseudoprofile technique based on satellite altimetry largely confirm this time history. A global correction is presented and applied to estimates of the thermosteric component of sea level rise. The XBT fall rate minimum from 1975 to 1985 appears as a 10-yr "warm period" in the global ocean in thermosteric sea level and heat content estimates using uncorrected data. Upon correction, the thermosteric sea level curve has reduced decadal variability and a larger, steadier long-term trend.
C1 [Wijffels, Susan E.; Domingues, Catia M.; Barker, Paul; White, Neil J.; Gronell, Ann; Ridgway, Ken; Church, John A.] Ctr Australian Weather & Climate Res, Hobart, Tas, Australia.
[Willis, Josh] CALTECH, Jet Prop Lab, Pasadena, CA USA.
[White, Neil J.; Church, John A.] Antarctic Climate & Ecosyst Cooperat Res Ctr, Hobart, Tas, Australia.
RP Wijffels, SE (reprint author), CSIRO Marine & Atmospher Res, GPO 1538, Hobart, Tas 7000, Australia.
EM susan.wijffels@csiro.au
RI Wijffels, Susan/I-8215-2012; White, Neil/B-2077-2013; Church,
John/A-1541-2012; Domingues, Catia /A-2901-2015
OI Church, John/0000-0002-7037-8194; Domingues, Catia /0000-0001-5100-4595
NR 30
TC 140
Z9 142
U1 0
U2 13
PU AMER METEOROLOGICAL SOC
PI BOSTON
PA 45 BEACON ST, BOSTON, MA 02108-3693 USA
SN 0894-8755
EI 1520-0442
J9 J CLIMATE
JI J. Clim.
PD NOV
PY 2008
VL 21
IS 21
BP 5657
EP 5672
DI 10.1175/2008JCLI2290.1
PG 16
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 367ZN
UT WOS:000260591200014
ER
PT J
AU Vavrus, S
Waliser, D
AF Vavrus, Steve
Waliser, Duane
TI An Improved Parametrization for Simulating Arctic Cloud Amount in the
CCSM3 Climate Model
SO JOURNAL OF CLIMATE
LA English
DT Article
ID POLAR PATHFINDER DATASET; RADIATION PROPERTIES; SEA-ICE; COUPLED MODELS;
RECENT TRENDS; ANNUAL CYCLE; PART II; SURFACE; PARAMETERIZATION;
PRECIPITATION
AB A simple alternative parametrization for predicting cloud fraction in the Community Climate System Model, version 3 (CCSM3) global climate model is presented. This formula, dubbed "freezedry," is designed to alleviate the bias of excessive low clouds during polar winter by reducing the cloud amount under very dry conditions. During winter, freezedry decreases the low cloud amount over the coldest regions in high latitudes by over 50% locally and more than 30% averaged across the Arctic. The cloud reduction causes an Arctic-wide drop of 15 W m(-2) in surface cloud radiative forcing (CRF) during winter and about a 50% decrease in mean annual Arctic CRF. Consequently, wintertime surface temperatures fall by up to 4 K on land and 2-8 K over the Arctic Ocean, thus significantly reducing the model's pronouncfed warm bias. Freezedry also affects CCSM3's sensitivity to greenhouse forcing. In a transient-CO2 experiment, the model version with freezedry warms up to 20% less in the North Polar and South Polar regions (1.5- and 0.5-K-smaller warming, respectively). Paradoxically, the muted high-latitude response occurs despite a much larger increase in cloud amount with freezedry during nonsummer months (when clouds warm the surface), apparently because of the colder modern reference climate. While improving the polar climate simulation in CCSM3, freezedry has virtually no influence outside of very cold regions and has already been implemented in another climate model, the Global Environmental and Ecological Simulation of Ecological Systems, version 1 (GENESIS1). Furthermore, the simplicity of this parametrization allows it to be readily incorporated into other GCMs, many of which also suffer from excessive wintertime polar cloudiness.
C1 [Vavrus, Steve] Univ Wisconsin, Ctr Climat Res, Madison, WI 53706 USA.
[Waliser, Duane] CALTECH, Jet Prop Lab, Water & Carbon Cycles Grp, Pasadena, CA USA.
RP Vavrus, S (reprint author), Univ Wisconsin, Ctr Climat Res, 1225 W Dayton St, Madison, WI 53706 USA.
EM sjvavrus@wisc.edu
NR 62
TC 52
Z9 53
U1 0
U2 7
PU AMER METEOROLOGICAL SOC
PI BOSTON
PA 45 BEACON ST, BOSTON, MA 02108-3693 USA
SN 0894-8755
EI 1520-0442
J9 J CLIMATE
JI J. Clim.
PD NOV
PY 2008
VL 21
IS 21
BP 5673
EP 5687
DI 10.1175/2008JCLI2299.1
PG 15
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 367ZN
UT WOS:000260591200015
ER
PT J
AU Yong, A
Houch, SE
Abrams, MJ
Wills, CJ
AF Yong, Alan
Houch, Susan E.
Abrams, Michael J.
Wills, Christopher J.
TI Preliminary results for a semi-automated quantification of site effects
using geomorphometry and ASTER satellite data for Mozambique, Pakistan
and Turkey
SO JOURNAL OF EARTH SYSTEM SCIENCE
LA English
DT Article
DE Shear-wave velocity; site conditions; geomorphometry; terrain modeling;
object-oriented; satellite data; Geophysics; Geomorphology; remote
sensing
ID SPACEBORNE THERMAL EMISSION; REFLECTION RADIOMETER ASTER; SEISMIC
RESPONSE; CALIFORNIA; GEOLOGY; VELOCITY; MOTION; WAVES; MAP
AB Estimation of the degree of local seismic wave amplification (site effects) requires precise information about the local site conditions. In many regions of the world, local geologic information is either sparse or is not readily available. Because of this, seismic hazard maps for countries such as Mozambique, Pakistan and Turkey are developed without consideration of site factors and, therefore, do not provide a complete assessment of future hazards. Where local geologic information is available, details on the traditional maps often lack the precision (better than 1:10,000 scale) or the level of information required for modern seismic microzonation requirements. We use high-resolution (1:50,000) satellite imagery and newly developed image analysis methods to begin addressing this problem. Our:imagery, consisting of optical data and digital elevation models (DEMs), is recorded from the ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer) sensor system. We apply a semi-automated, object-oriented, multi-resolution feature segmentation method to identify and extract local terrain features. Then we classify the terrain types into mountain, piedmont and basin units using geomorphometry (topographic slope) as our parameter. Next, on the basis of the site classification schemes from the Wills and Silva (1998) study and the Wills et al (2000) and Wills and Clahan (2006) maps of California, we assign the local terrain units with V(s)30 (the average seismic shear-wave velocity through the upper 30 m of the subsurface) ranges for selected regions in Mozambique, Pakistan and Turkey. We find that the applicability of our site class assignments in each region is a good first-approximation for quantifying local site conditions and that additional work, such as the verification of the terrain's compositional. rigidity, is needed.
C1 [Yong, Alan; Houch, Susan E.] US Geol Survey, Pasadena, CA 91106 USA.
[Abrams, Michael J.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[Wills, Christopher J.] Calif Geol Survey, Sacramento, CA 95814 USA.
RP Yong, A (reprint author), US Geol Survey, 525 S Wilson Ave, Pasadena, CA 91106 USA.
EM yong@usgs.gov
FU U.S. Geological Survey Working Capital Fund
FX We greatly appreciate the helpful comments by Robert S Dollar and Karen
R Felzer, in addition to earlier discussions with Edward E Field and Ken
W Hudnut. We also greatly appreciate technical guidance from Matthias,
Stolz and John Parker of Definiens A.G. Work done by Michael J Abrams
was performed at the Jet Propulsion Laboratory/California, Institute of
Technology, under contract to the National Aeronautics and Space
Administration. we thank Linda Gundersen for the partial support through
U.S. Geological Survey Working Capital Fund.
NR 41
TC 5
Z9 5
U1 0
U2 5
PU INDIAN ACAD SCIENCES
PI BANGALORE
PA C V RAMAN AVENUE, SADASHIVANAGAR, P B #8005, BANGALORE 560 080, INDIA
SN 0253-4126
J9 J EARTH SYST SCI
JI J. Earth Syst. Sci.
PD NOV
PY 2008
VL 117
BP 797
EP 808
DI 10.1007/s12040-008-0061-7
PG 12
WC Geosciences, Multidisciplinary; Multidisciplinary Sciences
SC Geology; Science & Technology - Other Topics
GA 404QE
UT WOS:000263167300012
ER
PT J
AU Dou, FG
Ping, CL
Guo, LD
Jorgenson, T
AF Dou, Fugen
Ping, Chien-Lu
Guo, Laodong
Jorgenson, Torre
TI Estimating the Impact of Seawater on the Production of Soil
Water-Extractable Organic Carbon during Coastal Erosion
SO JOURNAL OF ENVIRONMENTAL QUALITY
LA English
DT Article
ID AGRICULTURAL SOILS; MOLECULAR-WEIGHT; ARCTIC ALASKA; MATTER; FOREST;
DOC; DIOXIDE; QUALITY; OCEAN; CU
AB The production of water-extractable organic carbon (WEOC) during arctic coastal erosion and permafrost degradation may contribute significantly to C fluxes under warming conditions, but it remains difficult to quantify. A tundra soil collected near Barrow, AK, was selected to evaluate the effects of soil pretreatments (oven drying vs. freeze drying) as well as extraction solutions (pure water vs. seawater) on WEOC yields. Both oven drying and freeze drying significantly increased WEOC release compared with the original moist soil samples; dried samples released, on average, 18% more WEOC than did original moist samples. Similar results were observed for the production of low-molecular-weight dissolved organic C. However, extractable OC released from different soil horizons exhibited differences in specific UV absorption, Suggesting differences in WEOC quality. Furthermore, extractable OC yields were significantly less in samples extracted with seawater compared with those extracted with pure water, likely due to the effects of major ions on extractable OC flocculation. Compared with samples from the active horizons, upper permafrost samples released more WEOC, suggesting that continuously frozen samples were more sensitive than samples that had experienced more drying-wetting cycles in nature. Specific UV absorption of seawater-extracted OC was significantly lower than that of OC extracted using pure water, suggesting more aromatic or humic substances were flocculated during seawater extraction. Our results Suggest that overestimation of total terrestrial WEOC input to the Arctic Ocean during coastal erosion could occur if estimations were based on WEOC extracted from dried soil samples using pure water.
C1 [Dou, Fugen; Ping, Chien-Lu] Univ Alaska, Dep Anim Plant & Soil Sci, Fairbanks, AK 99645 USA.
[Guo, Laodong] Univ So Mississippi, Stennis Space Ctr, Dept Marine Sci, Stennis Space Ctr, MS 39529 USA.
[Jorgenson, Torre] ABR Inc, Fairbanks, AK 99708 USA.
RP Dou, FG (reprint author), Univ Alaska, Dep Anim Plant & Soil Sci, Fairbanks, AK 99645 USA.
EM fdou@ucdavis.edu
RI Guo, Laodong/F-6045-2010; Dou, Fugen/B-8696-2011
OI Guo, Laodong/0000-0002-5010-1630;
FU National Science Foundation (NSF-OPP) [0436179]; International Arctic
Research Center at the University Of Alaska, Fairbanks
FX We thank Gary Michaelson for his technical support during soil sampling,
Candace O'Connor for critical reading, and the editors and three
anonymous reviewers for constructive comments. This material is based on
work supported by the National Science Foundation (NSF-OPP no. 0436179)
and the International Arctic Research Center at the University Of
Alaska, Fairbanks.
NR 50
TC 10
Z9 10
U1 2
U2 17
PU AMER SOC AGRONOMY
PI MADISON
PA 677 S SEGOE RD, MADISON, WI 53711 USA
SN 0047-2425
J9 J ENVIRON QUAL
JI J. Environ. Qual.
PD NOV-DEC
PY 2008
VL 37
IS 6
BP 2368
EP 2374
DI 10.2134/jeq2007.0403
PG 7
WC Environmental Sciences
SC Environmental Sciences & Ecology
GA 372ZW
UT WOS:000260941800040
PM 18948491
ER
PT J
AU Kopasakis, G
Brinson, T
Credle, S
AF Kopasakis, George
Brinson, Thomas
Credle, Sydni
TI A Theoretical Solid Oxide Fuel Cell Model for System Controls and
Stability Design
SO JOURNAL OF FUEL CELL SCIENCE AND TECHNOLOGY
LA English
DT Article
AB As the aviation industry moves toward higher efficiency electrical power generation, all electric aircraft, or zero emissions and more quiet aircraft, fuel cells are sought as the technology that can deliver on these high expectations. The hybrid solid oxide fuel cell system combines the fuel cell with a microturbine to obtain up to 70% Cycle efficiency, and then distributes the electrical power to the loads via a power distribution system. The challenge is to understand the dynamics of this complex multidiscipline system and the design distributed controls that take the system through its operating conditions in a stable and safe manner while maintaining the system performance. This particular system is a power generation and a distribution system, and the fuel cell and microturbine model fidelity should be compatible with the dynamics of the power distribution system in order to allow proper stability and distributed controls design. The novelty in this paper is that, first, the case is made why a high fidelity,fuel cell model is needed for systems control and stability designs. Second, a novel modeling approach is proposed for the fuel cell that will allow the fuel cell and the power system to be integrated and designed,for stability, distributed controls, and other interface specifications. This investigation shows that for the fuel cell, the voltage characteristic should be modeled, but in addition, conservation equation dynamics, ion diffusion, charge transfer kinetics, and the electron flow inherent impedance should also be included.
C1 [Kopasakis, George] NASA, Glenn Res Ctr, Cleveland, OH 44135 USA.
[Brinson, Thomas; Credle, Sydni] Florida A&M Univ, Tallahassee, FL 32307 USA.
RP Kopasakis, G (reprint author), NASA, Glenn Res Ctr, 21000 Brookpk Rd, Cleveland, OH 44135 USA.
NR 21
TC 0
Z9 0
U1 0
U2 2
PU ASME-AMER SOC MECHANICAL ENG
PI NEW YORK
PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA
SN 1550-624X
J9 J FUEL CELL SCI TECH
JI J. Fuel Cell Sci. Technol.
PD NOV
PY 2008
VL 5
IS 4
AR 041007
DI 10.1115/1.2971018
PG 8
GA 359EM
UT WOS:000259969200007
ER
PT J
AU Lu, P
Griffin, BJ
Dukeman, GA
Chavez, FR
AF Lu, Ping
Griffin, Brian J.
Dukeman, Gregory A.
Chavez, Frank R.
TI Rapid Optimal Multiburn Ascent Planning and Guidance
SO JOURNAL OF GUIDANCE CONTROL AND DYNAMICS
LA English
DT Article; Proceedings Paper
CT AIAA Guidance, Navigation, and Control Conference
CY AUG 20-23, 2007
CL Hilton Head Isl, SC
ID TRAJECTORIES; OPTIMIZATION; ARCS
AB This paper provides detailed development of an analytical multiple-shooting method for rapid and reliable generation of the optimal exoatmospheric ascent trajectory of a launch vehicle. The trajectory consists of two burns (stages) and an optimal coast arc between the two burns. The problem is known to be highly sensitive and challenging. The problem solution is given in closed form and quadratures and key development details are presented. An indepth analysis of a transversality condition in the optimal ascent problem is conducted to gain better understanding of the problem. The analysis reveals several properties that allow us to overcome a numerical difficulty caused by a scaling mismatch in the transversality condition. This measure is instrumental in increasing the convergence reliability of the algorithm. A dogleg trust-region method that is more robust than the classical Newton-Raphson method is employed for the numerical solution. The multiple-shooting formulation, constraint simplification, and more sophisticated numerical method are all aimed at enhancing the robustness of the algorithm for this otherwise difficult problem. The final product of combining all of these techniques is a very reliable, effective, and fast algorithm. Such an algorithm can be a valuable tool in rapid planning of launch missions and in onboard applications for closed-loop guidance.
C1 [Lu, Ping] Iowa State Univ, Dept Aerosp Engn, Ames, IA 50011 USA.
[Dukeman, Gregory A.] NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA.
[Chavez, Frank R.] USAF, Res Lab, Space Vehicles Directorate, Kirtland AFB, NM 87117 USA.
RP Lu, P (reprint author), Iowa State Univ, Dept Aerosp Engn, 2271 Howe Hall, Ames, IA 50011 USA.
EM plu@iastate.edu; Brian.J.Griffin@nasa.gov; Greg.Dukeman@nasa.gov
NR 21
TC 18
Z9 25
U1 2
U2 8
PU AMER INST AERONAUT ASTRONAUT
PI RESTON
PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA
SN 0731-5090
J9 J GUID CONTROL DYNAM
JI J. Guid. Control Dyn.
PD NOV-DEC
PY 2008
VL 31
IS 6
BP 1656
EP 1664
DI 10.2514/1.36084
PG 9
WC Engineering, Aerospace; Instruments & Instrumentation
SC Engineering; Instruments & Instrumentation
GA 369YA
UT WOS:000260728600011
ER
PT J
AU Zeng, J
Baldelli, DH
Brenner, M
AF Zeng, Jie
Baldelli, Dario H.
Brenner, Martin
TI Novel Nonlinear Hammerstein Model Identification: Application to
Nonlinear Aeroelastic/Aeroservoelastic System
SO JOURNAL OF GUIDANCE CONTROL AND DYNAMICS
LA English
DT Article; Proceedings Paper
CT AIAA Atmospheric Flight Mechanics Conference
CY AUG, 2007
CL Hilton Head Isl, SC
ID SEPARABLE LEAST-SQUARES; ORTHONORMAL BASES; LINEAR-SYSTEMS; ALGORITHM
AB In this paper, a novel iterative algorithm for the identification of a nonlinear Hammerstein system is presented. The proposed algorithm is based on the iterative estimation and the orthonormal basis functions. The linear part of the Hammerstein cascade system is represented by the orthonormal finite impulse response filter, and the static nonlinear part is represented by the cubic spline function. The advantage of using orthonormal bases in the orthonormal finite impulse response filter lies in the possibility of incorporating prior poles knowledge of the system dynamics into the identification process. As a result, more accurate and simplified linear models can be obtained with a limited number of basis functions. Using the cubic spline function instead of the polynomial will greatly improve the extrapolation capability of the static identified nonlinearity. Furthermore, a criterion based on the frequency-domain identification method and stabilization diagram is introduced to estimate the physical poles of the dynamic system. Two case studies including a simulated structurally nonlinear prototypical two-dimensional wing section are presented to illustrate the proposed identification algorithm.
C1 [Zeng, Jie; Baldelli, Dario H.] ZONA Technol Inc, Scottsdale, AZ 85258 USA.
[Brenner, Martin] NASA Dryden Flight Res Ctr, Edwards AFB, CA 93523 USA.
RP Zeng, J (reprint author), ZONA Technol Inc, Scottsdale, AZ 85258 USA.
NR 26
TC 6
Z9 9
U1 2
U2 6
PU AMER INST AERONAUT ASTRONAUT
PI RESTON
PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA
SN 0731-5090
J9 J GUID CONTROL DYNAM
JI J. Guid. Control Dyn.
PD NOV-DEC
PY 2008
VL 31
IS 6
BP 1677
EP 1686
DI 10.2514/1.35719
PG 10
WC Engineering, Aerospace; Instruments & Instrumentation
SC Engineering; Instruments & Instrumentation
GA 369YA
UT WOS:000260728600013
ER
PT J
AU Markley, FL
Sedlak, JE
AF Markley, F. Landis
Sedlak, Joseph E.
TI Kalman Filter for Spinning Spacecraft Attitude Estimation
SO JOURNAL OF GUIDANCE CONTROL AND DYNAMICS
LA English
DT Article
ID QUATERNION; CONSTRAINT
AB This paper presents a Kalman filter using a seven-component attitude state vector comprising the angular momentum components in an inertial reference frame, the angular momentum components in the body frame, and a rotation angle. The relatively slow variation of these parameters makes this parameterization advantageous for spinning spacecraft attitude estimation. The filter accounts for the constraint that the magnitude of the angular momentum vector is the same in the inertial and body frames by employing a reduced six-component error state. Three variants of the filter, defined by different choices for the reduced error state, are tested against a quaternion-based filter using simulated data for the THEMIS mission. The infinitesimal attitude error angles are components of the error state in two of these variants, facilitating the computation of measurement sensitivity matrices and causing the usual 3 x 3 attitude covariance matrix to be a submatrix of the 6 x 6 covariance of the error state. These variants differ in their choice for the other three components of the error state, using either the angular momentum errors in the spacecraft body frame or in the inertial frame. The latter variant shows the best combination of robustness and efficiency in the simulations. Attitude estimation results using THEMIS flight data are also presented.
C1 [Markley, F. Landis] NASA, Goddard Space Flight Ctr, Guidance Navigat & Control Syst Engn Branch, Greenbelt, MD 20771 USA.
[Sedlak, Joseph E.] ai Solut Inc, Lanham, MD 20706 USA.
RP Markley, FL (reprint author), NASA, Goddard Space Flight Ctr, Guidance Navigat & Control Syst Engn Branch, Code 591, Greenbelt, MD 20771 USA.
NR 26
TC 16
Z9 17
U1 1
U2 10
PU AMER INST AERONAUT ASTRONAUT
PI RESTON
PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA
SN 0731-5090
J9 J GUID CONTROL DYNAM
JI J. Guid. Control Dyn.
PD NOV-DEC
PY 2008
VL 31
IS 6
BP 1750
EP 1760
DI 10.2514/1.35221
PG 11
WC Engineering, Aerospace; Instruments & Instrumentation
SC Engineering; Instruments & Instrumentation
GA 369YA
UT WOS:000260728600020
ER
PT J
AU Jah, MK
Lisano, ME
Born, GH
Axelrad, P
AF Jah, Moriba K.
Lisano, Michael E., II
Born, George H.
Axelrad, Penina
TI Mars Aerobraking Spacecraft State Estimation by Processing Inertial
Measurement Unit Data
SO JOURNAL OF GUIDANCE CONTROL AND DYNAMICS
LA English
DT Article; Proceedings Paper
CT SpaceOps 2006 Conference
CY JUN 19-23, 2006
CL Rome, ITALY
AB Aerobraking is an efficient technique for orbit adjustment of planetary spacecraft, such as the Magellan (Venue), the Mars Global Surveyor, and the Mars Odyssey. Determination of the vehicle state during the aerobraking phase has conventionally been performed using only radiometric tracking data before and following the atmospheric drag pass. This approach is sufficiently accurate and timely to meet current mission operational requirements; however, it is human-hour-intensive and leads to delayed results because of the need for post-drag-pass data. This research presents a new approach to estimation of the vehicle state during the atmospheric pass that sequentially incorporates observations from an inertial measurement unit and models of the vehicle and environment. The approach, called inertial measurements for aeroassisted navigation, has a comparable navigation accuracy and superior availability of the results immediately after completion of the pass against current navigation team solutions. Furthermore, the research shows that inertial measurements for aeroassisted navigation can be used to reliably predict subsequent periapsis times and locations over all aerobraking regimes; it also yields accurate peak dynamic pressure and heating rates, critical for a successful corridor control strategy. This research also provides the first instance of the utilization of the unscented Kalman filter for the purpose of estimating an actual spacecraft trajectory arc about another planet.
C1 [Jah, Moriba K.] USAF, Res Lab, Kihei, HI 96753 USA.
[Lisano, Michael E., II] CALTECH, Jet Prop Lab, Guidance Navigat & Control Sect, Pasadena, CA 91040 USA.
[Axelrad, Penina] Univ Colorado, Colorado Ctr Astrodynam Res, Boulder, CO 80309 USA.
RP Jah, MK (reprint author), USAF, Res Lab, Air Force Maui Opt & Supercomp Site,535 Lipoa Pkw, Kihei, HI 96753 USA.
OI Jah, Moriba/0000-0003-1109-0374
NR 21
TC 3
Z9 3
U1 0
U2 2
PU AMER INST AERONAUT ASTRONAUT
PI RESTON
PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA
SN 0731-5090
J9 J GUID CONTROL DYNAM
JI J. Guid. Control Dyn.
PD NOV-DEC
PY 2008
VL 31
IS 6
BP 1802
EP 1813
DI 10.2514/1.24304
PG 12
WC Engineering, Aerospace; Instruments & Instrumentation
SC Engineering; Instruments & Instrumentation
GA 369YA
UT WOS:000260728600025
ER
PT J
AU Nguyen, N
Krishnakumar, K
Kaneshige, J
Nespeca, P
AF Nguyen, Nhan
Krishnakumar, Kalmanje
Kaneshige, John
Nespeca, Pascal
TI Flight Dynamics and Hybrid Adaptive Control of Damaged Aircraft (vol 31,
pg 751, 2008)
SO JOURNAL OF GUIDANCE CONTROL AND DYNAMICS
LA English
DT Correction
C1 [Nguyen, Nhan; Krishnakumar, Kalmanje; Kaneshige, John] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
[Nespeca, Pascal] Univ Calif Davis, Davis, CA 95616 USA.
RP Nguyen, N (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
NR 2
TC 1
Z9 1
U1 0
U2 2
PU AMER INST AERONAUT ASTRONAUT
PI RESTON
PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA
SN 0731-5090
J9 J GUID CONTROL DYNAM
JI J. Guid. Control Dyn.
PD NOV-DEC
PY 2008
VL 31
IS 6
BP 1837
EP 1838
DI 10.2514/1.39924
PG 2
WC Engineering, Aerospace; Instruments & Instrumentation
SC Engineering; Instruments & Instrumentation
GA 369YA
UT WOS:000260728600032
ER
PT J
AU Mackowski, DW
Mishchenko, MI
AF Mackowski, Daniel W.
Mishchenko, Michael I.
TI Prediction of thermal emission and exchange among neighboring
wavelength-sized spheres
SO JOURNAL OF HEAT TRANSFER-TRANSACTIONS OF THE ASME
LA English
DT Article
DE nanoscale heat transfer; electromagnetic scattering; spheres; radiative
heat transfer
ID T-MATRIX; SCATTERING
AB An analysis of radiative emission and radiative exchange among an ensemble of closely spaced, wavelength-sized spheres, in which each sphere in the ensemble is at a distinct and uniform temperature, is presented. We show that the rate of spectral emission from a specific sphere in the ensemble and the rate at which emission is exchanged between a pair of spheres can be deduced from the application of reciprocity and energy conservation principles to the solution of Maxwell's time harmonic wave equations for a sphere ensemble that is exposed to a plane wave incident field of wavelength lambda. We show that in the limit of d/lambda -> 0, the emissive exchange between a pair of spheres becomes inversely proportional to the gap thickness d. We also show that when the spheres are in the mutual far-field zones of each other, the emissive exchange between the spheres can be well approximated by geometric configuration factors, with an effective area correction to account for finite wavelength effects.
C1 [Mackowski, Daniel W.] Auburn Univ, Dept Mech Engn, Auburn, AL 36849 USA.
[Mishchenko, Michael I.] NASA, Goddard Inst Space Studies, New York, NY 10025 USA.
RP Mackowski, DW (reprint author), Auburn Univ, Dept Mech Engn, Auburn, AL 36849 USA.
EM mackodw@auburn.edu
RI Mackowski, Daniel/K-1917-2013; Mishchenko, Michael/D-4426-2012
NR 11
TC 6
Z9 6
U1 0
U2 2
PU ASME-AMER SOC MECHANICAL ENG
PI NEW YORK
PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA
SN 0022-1481
J9 J HEAT TRANS-T ASME
JI J. Heat Transf.-Trans. ASME
PD NOV
PY 2008
VL 130
IS 11
AR 112702
DI 10.1115/1.2957596
PG 7
WC Thermodynamics; Engineering, Mechanical
SC Thermodynamics; Engineering
GA 345DG
UT WOS:000258975600015
ER
PT J
AU Das, M
Madenci, E
Ambur, DR
AF Das, Manabendra
Madenci, Erdogan
Ambur, Damodar R.
TI THREE-DIMENSIONAL NONLINEAR ANALYSES OF SCARF REPAIR IN COMPOSITE
LAMINATES AND SANDWICH PANELS
SO JOURNAL OF MECHANICS OF MATERIALS AND STRUCTURES
LA English
DT Article
DE scarf repair; laminate; sandwich panels; nonlinear analyses
ID FINITE-ELEMENT; BONDED JOINTS; STRESS; FAILURE
AB A special-purpose analysis tool based on the finite element method is presented for parametric design studies of composite laminates and sandwich panels with scarf repairs. This design tool provides the complete three-dimensional stress and strain fields in scarf-repaired panels without any requirements on the nature of the lamination and the type of loading. The adherends are modeled using a plate element based on a higher-order single-layer theory, and the adhesive is modeled using a solid element. The higher-order nature of the plate theory makes it suitable for analyzing thick laminates and sandwich panels comprised of numerous plies. The model takes into account geometric nonlinearity in the adherends and assumes a bilinear stress-strain relationship for the adhesive. The responses of composite laminates with single-and double-sided repairs and sandwich panels with both full and partial repairs of the top face sheets are investigated.
C1 [Das, Manabendra; Madenci, Erdogan] Univ Arizona, Dept Aerosp & Mech Engn, Tucson, AZ 85721 USA.
[Ambur, Damodar R.] NASA, Res & Technol Directorate, Langley Res Ctr, Hampton, VA 23681 USA.
RP Das, M (reprint author), Univ Arizona, Dept Aerosp & Mech Engn, 1130 N Mt Ave, Tucson, AZ 85721 USA.
EM mdas@email.arizona.edu; madenci@email.arizona.edu;
damodar.r.ambur@nasa.gov
NR 20
TC 3
Z9 3
U1 2
U2 6
PU MATHEMATICAL SCIENCE PUBL
PI BERKELEY
PA UNIV CALIFORNIA, DEPT MATHEMATICS, BERKELEY, CA 94720-3840 USA
SN 1559-3959
J9 J MECH MATER STRUCT
JI J. Mech. Mater. Struct.
PD NOV
PY 2008
VL 3
IS 9
BP 1641
EP 1658
DI 10.2140/jomms.2008.3.1641
PG 18
WC Materials Science, Multidisciplinary; Mechanics
SC Materials Science; Mechanics
GA 399ZD
UT WOS:000262836900003
ER
PT J
AU Maruyama, B
Arepalli, S
AF Maruyama, Benji
Arepalli, Sivaram
TI The Proceedings of the Second Workshop on SWCNT Growth Mechanisms
Organized by NASA-JSC and Rice University
SO JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY
LA English
DT Editorial Material
C1 [Maruyama, Benji] USAF, Res Lab, Nanostructured & Biol Mat Branch, Wright Patterson AFB, OH USA.
[Arepalli, Sivaram] NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA.
RP Maruyama, B (reprint author), USAF, Res Lab, Nanostructured & Biol Mat Branch, Wright Patterson AFB, OH USA.
RI Arepalli, Sivaram/A-5372-2010; Maruyama, Benji/E-3634-2010
NR 0
TC 0
Z9 0
U1 0
U2 1
PU AMER SCIENTIFIC PUBLISHERS
PI STEVENSON RANCH
PA 25650 NORTH LEWIS WAY, STEVENSON RANCH, CA 91381-1439 USA
SN 1533-4880
J9 J NANOSCI NANOTECHNO
JI J. Nanosci. Nanotechnol.
PD NOV
PY 2008
VL 8
IS 11
BP 6052
EP 6052
DI 10.1166/jnn.2008.SW1a
PG 1
WC Chemistry, Multidisciplinary; Nanoscience & Nanotechnology; Materials
Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter
SC Chemistry; Science & Technology - Other Topics; Materials Science;
Physics
GA 379IV
UT WOS:000261390800068
ER
PT J
AU Allgood, D
Gutmark, E
Hoke, J
Bradley, R
Schauer, F
AF Allgood, Daniel
Gutmark, Ephraim
Hoke, John
Bradley, Royce
Schauer, Fred
TI Performance Studies of Pulse Detonation Engine Ejectors
SO JOURNAL OF PROPULSION AND POWER
LA English
DT Article
ID TUBE
AB An experimental study on the performance of pulse detonation engine ejectors was performed. Time-averaged thrust augmentation produced by straight and diverging pulse detonation engine ejectors was measured using a damped thrust stand. The ejector length-to-diameter ratio was varied from 1.25 to 5.62 by changing the length of the ejector and maintaining a nominal ejector diameter ratio of 2.75. In general, the level of thrust augmentation was found to increase with ejector length. Also, the ejector performance was observed to be strongly dependent on the operating fill fraction. A new nondimensional parameter incorporating the fill fraction was proposed. When the pulse detonation engine ejector data were represented as a function of this new parameter, the ejector data were reduced to one representative thrust augmentation curve for ejectors of similar internal geometry. Straight pulse detonation engine ejectors compared well with the available data on straight steady-flow ejectors. Diverging pulse detonation engine ejectors produced nearly twice the thrust augmentation as their straight-ejector counterparts due to the additional thrust surface area the divergence provided. All pulse detonation engine ejectors tested were seen to be sensitive to the axial position of the ejector as well. The optimum ejector axial placement was found to be a function of fill fraction due to a tradeoff between the detonation wave induced drag and increased
C1 [Gutmark, Ephraim] Univ Cincinnati, Dept Aerosp Engn, Cincinnati, OH 45221 USA.
[Hoke, John; Bradley, Royce] Innovat Sci Solut Inc, Dayton, OH 45440 USA.
[Schauer, Fred] USAF, Res Lab, Prop Directorate, Head Pulsed Detonat Res Facil, Wright Patterson AFB, OH 45433 USA.
RP Allgood, D (reprint author), NASA, Stennis Space Ctr, MS 39529 USA.
OI Gutmark, Ephraim/0000-0001-7816-4257
FU U.S. Air Force Research Laboratory and Innovative Scientific Solutions,
Inc.; NASA Glenn Research Center [NAG3-2669]; University of Cincinnati
FX The authors would like to thank the Propulsion Directorate at the U.S.
Air Force Research Laboratory and Innovative Scientific Solutions, Inc.,
for providing the financial support for this work. In addition, the
authors are grateful for the financial support from NASA Glenn Research
Center (NAG3-2669) for sponsoring the development of the University of
Cincinnati pulse detonation engine research facility. The technical
support of Curtis Rice of Innovative Scientific Solutions, Inc., is also
appreciated.
NR 23
TC 9
Z9 13
U1 0
U2 3
PU AMER INST AERONAUT ASTRONAUT
PI RESTON
PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA
SN 0748-4658
J9 J PROPUL POWER
JI J. Propul. Power
PD NOV-DEC
PY 2008
VL 24
IS 6
BP 1317
EP 1323
DI 10.2514/1.35001
PG 7
WC Engineering, Aerospace
SC Engineering
GA 372EX
UT WOS:000260886000015
ER
PT J
AU Rinsland, CP
Chiou, L
Mahieu, E
Zander, R
Boone, CD
Bernath, PF
AF Rinsland, Curtis P.
Chiou, Linda
Mahieu, Emmanuel
Zander, Rodolphe
Boone, Chris D.
Bernath, Peter F.
TI Measurements of long-term changes in atmospheric OCS (carbonyl sulfide)
from infrared solar observations
SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER
LA English
DT Article
DE Atmospheric carbonyl sulfide; Long-term lower stratospheric trend;
Infrared spectroscopy
ID MOLECULAR SPECTROSCOPIC DATABASE; STRATOSPHERE; TRENDS; RETRIEVALS;
LAYER; COS
AB Multi-decade atmospheric OCS (carbonyl sulfide) infrared measurements have been analyzed with the goal of quantifying long-term changes and evaluating the consistency of the infrared atmospheric OCS remote-sensing measurement record. Solar-viewing grating spectrometer measurements recorded in April 1951 at the jungfraujoch station (46.5 degrees N latitude, 8.0 degrees E longitude, 3.58 km altitude) show evidence for absorption by lines of the strong nu(3) band of OCS at 2062cm(-1). The observation predates the earliest previously reported OCS atmosphere remote-sensing measurement by two decades. More recent infrared ground-based measurements of OCS have been obtained primarily with high-resolution solar-viewing Fourier transform spectrometers (FTSs). Long-term trends derived from this record span more than two decades and show OCS columns that have remained constant or have decreased slightly with time since the Mt. Pinatubo eruption, though retrievals assuming different versions of public spectroscopic databases have been impacted by OCS nu(3) band line intensity differences of similar to 10%. The lower stratospheric OCS trend has been inferred assuming spectroscopic parameters from the high-resolution transmission (HITRAN) 2004 database. Volume mixing ratio (VMR) profiles measured near 30 degrees N latitude with high-resolution solar-viewing FTSs operating in the solar occultation mode over a 22 years time span were combined. Atmospheric Trace MOlecule Spectroscopy (ATMOS) version 3 FTS measurements in 1985 and 1994 were used with Atmospheric Chemistry Experiment (ACE) measurements during 2004-2007. Trends were calculated by referencing the measured OCS VMRs to those of the long-lived constituent N2O to account for variations in the dynamic history of the sampled airmasses. Means and 1-sigma standard deviations of VMRs (in ppbv, or 10(-9) per unit air volume) averaged over 30-100 hPa from measurements at 25-35 degrees N latitude are 0.334 +/- 0.089 ppbv from 1985 (ATMOS Spacelab 3 measurements), 0.297 +/- 0.094 ppbv from 1994 ATLAS 3 measurements, 0.326 +/- 0.074 ppbv from ACE 2004 measurements, 0.305 +/- 0.096 ppbv from ACE 2005 measurements, 0.328 +/- 0.074 from ACE 2006 measurements, and 0.305 +/- 0.090 ppbv from ACE measurements through August 2007. Assuming these parameters, we conclude that there has been no statistically significant trend in lower stratospheric OCS over the measurement time span. We discuss past measurement sets, quantify the impact of changes in infrared spectroscopic parameters on atmospheric retrievals and trend measurements, and discuss OCS spectroscopic uncertainties of the current nu(3) band parameters in public atmospheric databases. (C) 2008 Elsevier Ltd. All rights reserved.
C1 [Rinsland, Curtis P.] NASA, Langley Res Ctr, Sci Directorate, Hampton, VA 23681 USA.
[Chiou, Linda] Sci Syst & Applicat Inc, Hampton, VA 23666 USA.
[Mahieu, Emmanuel; Zander, Rodolphe] Univ Liege, Inst Astrophys & Geophys, B-4000 Sart Tilman Par Liege, Belgium.
[Boone, Chris D.; Bernath, Peter F.] Univ Waterloo, Dept Chem, Waterloo, ON N2L 3G1, Canada.
[Bernath, Peter F.] Univ York, Dept Chem, York YO10 5DD, N Yorkshire, England.
RP Rinsland, CP (reprint author), NASA, Langley Res Ctr, Sci Directorate, Mail Stop 401A, Hampton, VA 23681 USA.
EM curtis.p.rinsland@nasa.gov; linda.s.chiou@nasa.gov;
Emmanuel.Mahieu@ulg.ac.be; R.Zander@ulg.ac.be;
cboone@sciborg.uwaterloo.ca; bernath@uwaterloo.ca
RI Bernath, Peter/B-6567-2012;
OI Bernath, Peter/0000-0002-1255-396X; Mahieu, Emmanuel/0000-0002-5251-0286
FU NASA's Atmospheric Chemistry and Modeling Program (ACMAP); Upper
Atmosphere Research Program (UARP); Canadian Space Agency; Natural
Sciences and Engineering Research (NSERC) Council of Canada; Belgian
Federal Science Policy Office
FX Analysis of the ACE spectra at the NASA Langley Research Center was
supported by NASA's Atmospheric Chemistry and Modeling Program (ACMAP)
and Upper Atmosphere Research Program (UARP). Funding for ACE is
provided by the Canadian Space Agency and the Natural Sciences and
Engineering Research (NSERC) Council of Canada. E Mahieu was primarily
supported by the Belgian Federal Science Policy Office (PRODEX
Programme), Brussels. The authors thank Linda Brown and Frederick Irion
for making available the OCS parameters that were used in the version 3
ATMOS analysis.
NR 39
TC 13
Z9 13
U1 0
U2 8
PU PERGAMON-ELSEVIER SCIENCE LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
SN 0022-4073
EI 1879-1352
J9 J QUANT SPECTROSC RA
JI J. Quant. Spectrosc. Radiat. Transf.
PD NOV
PY 2008
VL 109
IS 16
BP 2679
EP 2686
DI 10.1016/j.jqsrt.2008.07.008
PG 8
WC Optics; Spectroscopy
SC Optics; Spectroscopy
GA 358VP
UT WOS:000259945900003
ER
PT J
AU Hwang, SM
Kojima, JN
Nguyen, QV
Rabinowitz, MJ
AF Hwang, Soon Muk
Kojima, Jun N.
Nguyen, Quang-Viet
Rabinowitz, Martin J.
TI Measurement of collision broadening of the P-1(5) line of (0,0) band of
OH A(2)Sigma(+) <- X-2 Pi transition at high temperatures
SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER
LA English
DT Article
DE OH; UV absorption spectroscopy; Collision broadening widths; Collision
broadening cross sections; Intermolecular potentials
ID RATE COEFFICIENT MEASUREMENTS; AIR COMBUSTION; HYDROGEN-AIR; FLAMES;
ABSORPTION; STATE; GAS
AB Even for the well-studied and ubiquitous species, OH, the current state of theoretical development of broadening theory does not allow extrapolation from low-temperature laboratory measurements to the range of practical combustion devices. We performed a series of experiments at typical combustion conditions to determine the collision broadening of the P-1(5) line of the (0,0) band of OH A(2)Sigma(+) <- X-2 Pi transition by Ar in shock-heated H-2-O-2-Ar mixtures and by air in H-2-air flames over a wide range of stoichiometry (phi = 0.01-10.0), temperature (T=780-2440K), and pressure (p = 0.7-10.0 atm). The values of the collision width, Delta nu(C), were acquired by fitting Voigt profiles to the measured spectral line shapes in flames and to the peak absorption coefficients (k(vo)) in shock tube experiments. Collision broadening parameters (2 gamma(Ar), 2 gamma(N2), and 2 gamma(H2O)) were then calculated assuming the linear dependence of Delta nu(C) with pressure-the 2 gamma(N2), and 2 gamma(H2O), values were inferred from 2 gamma(Air), and the equilibrium concentration of N-2 and H2O of a given flame. The temperature dependences of 2 gamma(i) in our temperature range are, respectively, 1.0, 0.75, and 0.87 for Ar, N-2, and H2O. The collision broadening cross sections (sigma) deduced from 2 gamma(i) values are expressed with an assumed form, sigma(i)(T) = sigma(i,0)(T-0/T)(k), T-0 = 1000 K: for Ar, sigma(Ar,0) = 63.3 (angstrom(2)), k = 0.50; for N-2, sigma N-2.0 = 68.0 (angstrom(2)), k 0.25: for H2O, sigma H-2O.0 = 188.8 (angstrom(2)), k = 0.37. Published by Elsevier Ltd.
C1 [Nguyen, Quang-Viet; Rabinowitz, Martin J.] NASA, Glenn Res Ctr Lewis Field, Cleveland, OH 44135 USA.
[Kojima, Jun N.] Ohio Aerosp Inst, Cleveland, OH 44142 USA.
[Hwang, Soon Muk] Univ Toledo, Dept Chem Engn, Toledo, OH 43606 USA.
RP Rabinowitz, MJ (reprint author), NASA, Glenn Res Ctr Lewis Field, 21000 Brook Pk Rd, Cleveland, OH 44135 USA.
EM martin.j.rabinowitz@nasa.gov
NR 32
TC 5
Z9 5
U1 0
U2 4
PU PERGAMON-ELSEVIER SCIENCE LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
SN 0022-4073
J9 J QUANT SPECTROSC RA
JI J. Quant. Spectrosc. Radiat. Transf.
PD NOV
PY 2008
VL 109
IS 16
BP 2715
EP 2724
DI 10.1016/j.jqsrt.2008.05.010
PG 10
WC Optics; Spectroscopy
SC Optics; Spectroscopy
GA 358VP
UT WOS:000259945900007
ER
PT J
AU Weltz, MA
Jolley, L
Nearing, M
Stone, J
Goodrich, D
Spaeth, K
Kiniry, J
Arnold, J
Bubenheim, D
Hernandez, M
Wei, HY
AF Weltz, Mark A.
Jolley, Leonard
Nearing, Mark
Stone, Jeff
Goodrich, Dave
Spaeth, Ken
Kiniry, Jim
Arnold, Jeff
Bubenheim, David
Hernandez, Mariano
Wei, Haiyan
TI Assessing the benefits of grazing land conservation practices
SO JOURNAL OF SOIL AND WATER CONSERVATION
LA English
DT Article
C1 [Weltz, Mark A.] USDA ARS, Reno, NV USA.
[Jolley, Leonard] USDA Nat Resources Conservat Serv NRCS, Beltsville, MD USA.
[Nearing, Mark; Stone, Jeff; Goodrich, Dave] USDA ARS, Tucson, AZ USA.
[Spaeth, Ken] USDA NRCS, Ft Worth, TX USA.
[Arnold, Jeff] USDA ARS, Temple, TX USA.
[Bubenheim, David] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
[Hernandez, Mariano; Wei, Haiyan] Univ Arizona, Tucson, AZ USA.
RP Weltz, MA (reprint author), USDA ARS, Reno, NV USA.
RI Goodrich, David/B-1763-2009
OI Goodrich, David/0000-0001-7735-1448
NR 7
TC 5
Z9 5
U1 0
U2 4
PU SOIL WATER CONSERVATION SOC
PI ANKENY
PA 945 SW ANKENY RD, ANKENY, IA 50023-9723 USA
SN 0022-4561
J9 J SOIL WATER CONSERV
JI J. Soil Water Conserv.
PD NOV-DEC
PY 2008
VL 63
IS 6
SI SI
BP 214A
EP 217A
DI 10.2489/jswc.63.6.214A
PG 4
WC Ecology; Soil Science; Water Resources
SC Environmental Sciences & Ecology; Agriculture; Water Resources
GA 374WI
UT WOS:000261074000011
ER
PT J
AU Luo, H
Churu, G
Fabrizio, EF
Schnobrich, J
Hobbs, A
Dass, A
Mulik, S
Zhang, Y
Grady, BP
Capecelatro, A
Sotiriou-Leventis, C
Lu, H
Leventis, N
AF Luo, H.
Churu, G.
Fabrizio, E. F.
Schnobrich, J.
Hobbs, A.
Dass, A.
Mulik, S.
Zhang, Y.
Grady, B. P.
Capecelatro, A.
Sotiriou-Leventis, C.
Lu, H.
Leventis, N.
TI Synthesis and characterization of the physical, chemical and mechanical
properties of isocyanate-crosslinked vanadia aerogels
SO JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY
LA English
DT Article; Proceedings Paper
CT 14th International Sol-Gel Conference
CY SEP 02-07, 2007
CL Montpellier, FRANCE
SP Int Sol Gel Soc
DE crosslinked vanadia aerogel; nano-foam; cryogenic temperature; specific
energy absorption; split Hopkinson pressure bar; digital image
correlation
ID AMINE-MODIFIED SILICA; CORE-SHELL SUPERSTRUCTURES; OXIDE AEROGELS;
COMPRESSION; TEMPERATURE; MONOLITHS; BEHAVIOR; SHEAR; BAR
AB A strong lightweight material (X-VOx) was formulated by nanocasting a conformal 4 nm thin layer of an isocyanate-derived polymer on the entangled worm-like skeletal framework of typical vanadia aerogels. The mechanical properties were characterized under both quasi-static loading conditions (dynamic mechanical analysis, compression and flexural bending testing) as well as high strain rate loading conditions using a split Hopkinson pressure bar (SHPB). The effects of mass density, moisture concentration and low temperature on the mechanical properties were determined and evaluated. Digital image correlation was used to measure the surface strains through analysis of images acquired by ultra-high speed photography, indicating nearly uniform compression at all stages of deformation during compression. The energy absorption of X-VOx was plotted as a function of the density, strain rate and temperature, and compared with that of plastic foams. X-VOx remains ductile even at -180 C, a characteristic not found in most materials. This unusual ductility is derived from interlocking and sintering-like fusion of nanoworms during compression. X-VOx emerges as an ideal material for force protection under impact.
C1 [Schnobrich, J.; Hobbs, A.; Leventis, N.] NASA, Glenn Res Ctr, Cleveland, OH 44135 USA.
[Luo, H.; Churu, G.; Zhang, Y.; Lu, H.] Oklahoma State Univ, Sch Mech & Aerosp Engn, Stillwater, OK 74078 USA.
[Fabrizio, E. F.] Ohio Aerosp Inst, Cleveland, OH 44142 USA.
[Dass, A.; Mulik, S.; Sotiriou-Leventis, C.; Leventis, N.] Missouri Univ Sci & Technol, Dept Chem, Rolla, MO 65409 USA.
[Grady, B. P.] Univ Oklahoma, Sch Chem Biol & Mat Engn, Norman, OK 73019 USA.
[Capecelatro, A.] Univ Calif Los Angeles, Dept Mat Sci, Los Angeles, CA 90024 USA.
RP Leventis, N (reprint author), NASA, Glenn Res Ctr, 21000 Brookpk Rd, Cleveland, OH 44135 USA.
EM cslevent@mst.edu; hongbing.lu@okstate.edu; leventis@mst.edu
RI Lu, Hongbing/A-1312-2011; Dass, Amal/A-2520-2011; Dass,
Amala/H-4729-2012
OI Dass, Amala/0000-0001-6942-5451
NR 37
TC 31
Z9 37
U1 2
U2 30
PU SPRINGER
PI DORDRECHT
PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS
SN 0928-0707
J9 J SOL-GEL SCI TECHN
JI J. Sol-Gel Sci. Technol.
PD NOV
PY 2008
VL 48
IS 1-2
BP 113
EP 134
DI 10.1007/s10971-008-1788-y
PG 22
WC Materials Science, Ceramics
SC Materials Science
GA 349IB
UT WOS:000259273400018
ER
PT J
AU Berger, KT
Greene, FA
Kimmel, R
Alba, C
Johnson, H
AF Berger, Karen T.
Greene, Frank A.
Kimmel, Roger
Alba, Christopher
Johnson, Heath
TI Aerothermodynamic Testing and Boundary-Layer Trip Sizing of the HIFiRE
Flight 1 Vehicle
SO JOURNAL OF SPACECRAFT AND ROCKETS
LA English
DT Article
ID ROUGHNESS
AB An experimental wind-tunnel test was conducted in the NASA Langley Research Center's 20 in. Mach 6 air tunnel in support of the Hypersonic International Flight Research Experimentation Program. The information in this paper focuses on the flight 1 configuration, the first in a series of flight experiments. The paper documents the experimental measurements made over Reynolds numbers ranging from 2.1 to 5.6 x 10(6)/ft and angles of attack from -5 to +5 deg on several scaled ceramic heat-transfer models of the flight I configuration. Global heat transfer was measured using phosphor thermography, and the resulting images and heat-transfer distributions were used to infer the state of the boundary layer on the vehicle wind- and lee-side surfaces. Boundary-layer trips were used to obtain turbulent heating information, and the experimental data highlighted in this paper were used to size and place the boundary-layer trip for the flight vehicle. The required height of the flight boundary-layer trip was determined to be 0.079 in., and the trip was moved from the design location of 7.87 to 20.47 in. to ensure that augmented heating would not impact the laminar side of the vehicle. The allowable roughness was selected to be 3.2 x 10(-3) in.
C1 [Berger, Karen T.; Greene, Frank A.] NASA, Langley Res Ctr, Aerothermodynam Branch, Hampton, VA 23681 USA.
[Kimmel, Roger] USAF, Res Lab, Wright Patterson AFB, OH 45433 USA.
[Alba, Christopher; Johnson, Heath] Univ Minnesota, Minneapolis, MN 55455 USA.
RP Berger, KT (reprint author), NASA, Langley Res Ctr, Aerothermodynam Branch, Mail Stop 408A, Hampton, VA 23681 USA.
NR 20
TC 5
Z9 5
U1 0
U2 4
PU AMER INST AERONAUT ASTRONAUT
PI RESTON
PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA
SN 0022-4650
J9 J SPACECRAFT ROCKETS
JI J. Spacecr. Rockets
PD NOV-DEC
PY 2008
VL 45
IS 6
BP 1117
EP 1124
DI 10.2514/1.38722
PG 8
WC Engineering, Aerospace
SC Engineering
GA 384MT
UT WOS:000261749600004
ER
PT J
AU Alba, CR
Johnson, HB
Bartkowicz, MD
Candler, GV
Berger, KT
AF Alba, Christopher R.
Johnson, Heath B.
Bartkowicz, Matthew D.
Candler, Graham V.
Berger, Karen T.
TI Boundary-Layer Stability Calculations for the HIFiRE-1 Transition
Experiment
SO JOURNAL OF SPACECRAFT AND ROCKETS
LA English
DT Article
AB Boundary-layer stability analysis is performed by computational fluid dynamic simulation of experiments conducted in the National Aeronautics and Space Administration Langley Research Center 20-in. Mach 6 Air Tunnel in support of the first flight of the Hypersonic International Flight Research Experimentation program. From the laminar computational flow solutions, disturbances are calculated using the linear parabolized stability equations to obtain integrated disturbance growth rates. Comparisons are made between the experimentally observed transition locations and the results of the stability analysis. The stability results from the NASA Langley Research Center Air Tunnel are combined with previous work done for the Calspan University at Buffalo Research Center Large-Energy National Shock Tunnel to show excellent correlation between predicted and observed boundary-layer transition locations. Roughness calculations are also performed and a Reynolds number based on trip height is tabulated with experimental results.
C1 [Alba, Christopher R.; Johnson, Heath B.; Bartkowicz, Matthew D.; Candler, Graham V.] Univ Minnesota, Dept Aerosp Engn & Mech, Minneapolis, MN 55455 USA.
[Berger, Karen T.] NASA, Langley Res Ctr, Aerothermodynam Branch, Hampton, VA 23681 USA.
RP Alba, CR (reprint author), Univ Minnesota, Dept Aerosp Engn & Mech, Minneapolis, MN 55455 USA.
FU U.S. Air Force Research Laboratory; Australian Defence Science
Technology Organisation (DSTO); Sandia National Laboratories [619327];
U.S. Air Force Office of Scientific Research [FA9550-04-1-0341]
FX HIFiRE is a joint program of the U.S. Air Force Research Laboratory and
the Australian Defence Science Technology Organisation (DSTO). The U.S.
portion of the technical program is managed by the U.S. Air Force
Research Laboratory Air Vehicles Directorate RBAA. This work was
sponsored by Sandia National Laboratories Award no. 619327 and by the
U.S. Air Force Office of Scientific Research under grant no.
FA9550-04-1-0341. The views and conclusions contained herein are those
of the authors and should not be interpreted as necessarily representing
the official policies or endorsements, either expressed or implied, of
the U.S. Government.
NR 24
TC 7
Z9 7
U1 0
U2 6
PU AMER INST AERONAUT ASTRONAUT
PI RESTON
PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA
SN 0022-4650
J9 J SPACECRAFT ROCKETS
JI J. Spacecr. Rockets
PD NOV-DEC
PY 2008
VL 45
IS 6
BP 1125
EP 1133
DI 10.2514/1.37445
PG 9
WC Engineering, Aerospace
SC Engineering
GA 384MT
UT WOS:000261749600005
ER
PT J
AU Johnston, CO
Hollis, BR
Sutton, K
AF Johnston, Christopher O.
Hollis, Brian R.
Sutton, Kenneth
TI Nonequilibrium Stagnation-Line Radiative Heating for Fire II
SO JOURNAL OF SPACECRAFT AND ROCKETS
LA English
DT Article
ID LUNAR-RETURN CONDITIONS; SHOCK-LAYER RADIATION; N-2
AB This paper presents a detailed analysis of the shock-layer radiative heating to the Fire II vehicle using a new air-radiation model and a viscous shock-layer flowfield model. This new air-radiation model contains the most up-to-date properties for modeling the atomic-line, atomic photoionization, molecular band, and non-Boltzmann processes. The applied viscous shock-layer flowfield analysis contains the same thermophysical properties and nonequilibrium models as the LAURA Navier-Stokes code. Radiation-flowfield coupling, or radiation cooling, is accounted for in detail in this study. It is shown to reduce the radiative heating by about 30 % for the peak radiative heating points, although reducing the convective heating only slightly. A detailed review of past Fire II radiative heating studies is presented. It is observed that the scatter in the radiation predicted by these past studies is mostly a result of the different flowfield chemistry models and the treatment of the electronic state populations. The present predictions provide, on average throughout the trajectory, a better comparison with Fire II flight data than any previous study. The magnitude of the vacuum ultraviolet contribution to the radiative flux is estimated from the calorimeter measurements. This is achieved using the radiometer measurements and the predicted convective heating. The vacuum ultraviolet radiation predicted by the present model agrees well with the vacuum ultraviolet contribution inferred from the Fire II calorimeter measurement, although only when radiation-flowfield coupling is accounted for.
C1 [Johnston, Christopher O.; Hollis, Brian R.] NASA, Langley Res Ctr, Hampton, VA 23681 USA.
[Sutton, Kenneth] Natl Inst Aerosp, Hampton, VA 24060 USA.
RP Johnston, CO (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA.
NR 43
TC 16
Z9 16
U1 0
U2 2
PU AMER INST AERONAUT ASTRONAUT
PI RESTON
PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA
SN 0022-4650
J9 J SPACECRAFT ROCKETS
JI J. Spacecr. Rockets
PD NOV-DEC
PY 2008
VL 45
IS 6
BP 1185
EP 1195
DI 10.2514/1.33008
PG 11
WC Engineering, Aerospace
SC Engineering
GA 384MT
UT WOS:000261749600010
ER
PT J
AU Desai, PN
Lyons, DT
Tooley, J
Kangas, J
AF Desai, Prasun N.
Lyons, Dan T.
Tooley, Jeff
Kangas, Julie
TI Entry, Descent, and Landing Operations Analysis for the Stardust Entry
Capsule
SO JOURNAL OF SPACECRAFT AND ROCKETS
LA English
DT Article
ID SAMPLE RETURN CAPSULE
AB On the morning of 15 January 2006, the Stardust capsule successfully landed at the Utah Test and Training Range in northwest Utah, returning cometary samples from the comet Wild-2. An overview of the entry, descent, and landing trajectory analysis that was performed for targeting during the mission operations phase upon final approach to Earth is described. The final orbit determination solution produced an inertial entry flight-path angle of -8.21 deg (the desired nominal value) with a 3-sigma uncertainty of +/- 0.0017 deg (2% of the requirement). The navigation and entry, descent, and landing operations effort accurately delivered the entry capsule to the desired landing site. The final landing location was 8.1 km from the target, which was well within the allowable landing area. Overall, the Earth approach operation procedures worked well and there were no issues (logistically or performance-based) that arose. As a result, the process of targeting a capsule from an interplanetary trajectory and accurately landing it on Earth was successfully demonstrated.
C1 [Desai, Prasun N.] NASA, Langley Res Ctr, Hampton, VA 23681 USA.
[Lyons, Dan T.; Tooley, Jeff; Kangas, Julie] CALTECH, Jet Prop Lab, Aero Applicat Grp, Pasadena, CA 91109 USA.
RP Desai, PN (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA.
EM prasun.n.desai@nasa.gov; daniel.t.lyons@jpl.nasa.gov;
jeffrey.tooley@jpl.nasa.gov; julie.a.kangas@jpl.nasa.gov
FU Jet Propulsion Laboratory; California Institute of Technology; NASA
FX A portion of this research was carried out at the Jet Propulsion
Laboratory, California Institute of Technology, under a contract with
NASA. Reference herein to any specific commercial product, process, or
service by trade name, trademark, manufacturer, or otherwise, does not
constitute or imply its endorsement by the U.S. Government or the Jet
Propulsion Laboratory, California Institute of Technology. The authors
would like to acknowledge the efforts of the entire spacecraft
operations, navigation, and entry, descent, and landing teams that
resulted in such a successful mission.
NR 14
TC 10
Z9 14
U1 0
U2 1
PU AMER INST AERONAUT ASTRONAUT
PI RESTON
PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA
SN 0022-4650
J9 J SPACECRAFT ROCKETS
JI J. Spacecr. Rockets
PD NOV-DEC
PY 2008
VL 45
IS 6
BP 1262
EP 1268
DI 10.2514/1.37090
PG 7
WC Engineering, Aerospace
SC Engineering
GA 384MT
UT WOS:000261749600018
ER
PT J
AU Covington, MA
Heineman, JM
Golstein, HE
Chen, YK
Terrazas-Salinas, I
Balboni, JA
Olejniczak, J
Martinez, ER
AF Covington, M. A.
Heineman, J. M.
Golstein, H. E.
Chen, Y. -K.
Terrazas-Salinas, I.
Balboni, J. A.
Olejniczak, J.
Martinez, E. R.
TI Performance of a Low Density Ablative Heat Shield Material (vol 45, pg
854, 2008)
SO JOURNAL OF SPACECRAFT AND ROCKETS
LA English
DT Correction
C1 [Covington, M. A.; Heineman, J. M.] Eloret Corp, Sunnyvale, CA 94086 USA.
[Golstein, H. E.] Adv Comp Sci Res Inst, Moffett Field, CA 94035 USA.
[Chen, Y. -K.; Terrazas-Salinas, I.; Balboni, J. A.; Olejniczak, J.; Martinez, E. R.] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
RP Covington, MA (reprint author), Eloret Corp, Sunnyvale, CA 94086 USA.
NR 1
TC 4
Z9 4
U1 1
U2 10
PU AMER INST AERONAUT ASTRONAUT
PI RESTON
PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA
SN 0022-4650
J9 J SPACECRAFT ROCKETS
JI J. Spacecr. Rockets
PD NOV-DEC
PY 2008
VL 45
IS 6
BP 1330
EP 1330
DI 10.2514/1.40599
PG 1
WC Engineering, Aerospace
SC Engineering
GA 384MT
UT WOS:000261749600027
ER
PT J
AU Roy, AS
Back, MR
Khoury, SF
Schneeberger, EW
Back, LH
Velury, VV
Millard, RW
Banerjee, RK
AF Roy, Abhijit Sinha
Back, Martin R.
Khoury, Saeb F.
Schneeberger, Eric W.
Back, Lloyd H.
Velury, Vijaya V.
Millard, Ronald W.
Banerjee, Rupak K.
TI Functional and Anatomical Diagnosis of Coronary Artery Stenoses
SO JOURNAL OF SURGICAL RESEARCH
LA English
DT Article
DE coronary circulation; fractional flow reserve; coronary flow reserve;
hemodynamics
ID FRACTIONAL FLOW RESERVE; LESION SEVERITY; MICROVASCULAR RESISTANCE;
PRESSURE; ASSOCIATION; ANGIOGRAPHY; GUIDEWIRES; VALIDATION; CARDIOLOGY;
THERAPY
AB Background. Functional/physiological evaluation of coronary artery stenoses may be more important than anatomical measurements of severity. Optimization of thresholds for stenosis intervention and treatment endpoints depend on coupling functional hemodynamic and anatomical data. We sought to develop a single prognostic parameter correlating stenosis-specific anatomy, pressure gradient, and velocities that could be measured during catheterization.
Materials and methods. In vivo Experiments were performed in six swine (41 +/- 3 kg). The lumen area of the left anterior descending coronary artery was measured with intravascular ultrasound. An angioplasty balloon was inflated to create the desired intraluminal area obstructions. Fractional flow reserve (FFR), coronary flow reserve (CFR), and hyperemic-stenosis-resistance index were measured distal to the balloon at peak hyperemia with 10 mg intracoronary papaverine. A functional index:pressure drop coefficient (CDP) and a combined functional and anatomical index:lesion flow coefficient (LFC) were calculated from measured hyperemic pressure gradient, velocity, and percentage area stenosis. P < 0.05 was considered statistically significant.
Results. The CDP and LFC correlated linearly and significantly with FFR and CFR. The CDP (R-2 = 0.72, P < 0.0001) correlated better than LFC (R-2 = 0.19, P < 0.003) with hyperemic-stenosis-resistance index. When LFC was correlated simultaneously with FFR and CFR, R-2 improved to 0.82 (P < 0.0001). Inclusion of percentage area stenoses concurrently with FFR and CFR marginally improved the correlation with LFC.
Conclusions. A dimensionless parameter combining measured pressure gradient, velocity, and area reduction data can optimally define the severity of coronary stenoses based on our preliminary results and could prove useful clinically. (c) 2008 Elsevier Inc. All rights reserved.
C1 [Roy, Abhijit Sinha; Banerjee, Rupak K.] Univ Cincinnati, Dept Mech Engn, Cincinnati, OH 45221 USA.
[Banerjee, Rupak K.] Univ Cincinnati, Dept Biomed Engn, Cincinnati, OH 45221 USA.
[Khoury, Saeb F.; Velury, Vijaya V.] Univ Cincinnati, Dept Internal Med, Div Cardiol, Cardiac Catheterizat Lab, Cincinnati, OH 45221 USA.
[Schneeberger, Eric W.] Univ Cincinnati, Dept Surg, Div Cardiac Surg, Cincinnati, OH 45221 USA.
[Millard, Ronald W.] Univ Cincinnati, Dept Pharmacol & Cell Biophys, Cincinnati, OH 45221 USA.
[Back, Lloyd H.] CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA.
[Back, Martin R.] Univ S Florida Hlth, Div Vasc & Endovasc Surg, Bay Pines, FL USA.
RP Banerjee, RK (reprint author), Univ Cincinnati, Dept Mech Engn, 598 Rhodes Hall,POB 210072, Cincinnati, OH 45221 USA.
EM Rupak.Banerjee@UC.Edu
FU merican Heart Association National-Scientific Development Grant (AHA
National-SDG) [0335270N]
FX This work was supported by American Heart Association
National-Scientific Development Grant (AHA National-SDG Grant 0335270N).
The authors are also grateful to K. D. Ashtekar, M. Krishnamoorthy, R.
R. Raghunathan, B. Arunachalani of Bio-fluid, heat, and mass transfer
laboratory at University of Cincinnati for their assistance during the
experiments.
NR 29
TC 18
Z9 19
U1 0
U2 3
PU ACADEMIC PRESS INC ELSEVIER SCIENCE
PI SAN DIEGO
PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA
SN 0022-4804
J9 J SURG RES
JI J. Surg. Res.
PD NOV
PY 2008
VL 150
IS 1
BP 24
EP 33
DI 10.1016/j.jss.2007.10.018
PG 10
WC Surgery
SC Surgery
GA 361SI
UT WOS:000260147000005
ER
PT J
AU Kandula, M
AF Kandula, Max
TI Spectral attenuation of sound in dilute suspensions with nonlinear
particle relaxation
SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA
LA English
DT Article
ID EMULSIONS; PROPAGATION; DISPERSION; ULTRASOUND; WAVES
AB Previous studies on the sound attenuation in particle-laden flows under Stokesian drag and conduction-controlled heat transfer have been extended to accommodate the nonlinear drag and heat transfer. It has been shown that for large particle-to-fluid density ratio, the particle Reynolds number bears a cubic relationship with omega tau(d) (where omega is the circular frequency and tau(d) is the Stokesian particle relaxation time). This dependence leads to the existence of a peak value in the linear absorption coefficient occurring at a finite value of omega tau(d). Comparison of the predictions with the test data for the spectral attenuation of sound with water injection in a perfectly expanded supersonic air jet shows a satisfactory trend of the theory accounting for nonlinear particle relaxation processes. (C) 2008 Acoustical Society of America
C1 NASA, ASRC Aerosp, Kennedy Space Ctr, FL 32899 USA.
RP Kandula, M (reprint author), NASA, ASRC Aerosp, Kennedy Space Ctr, FL 32899 USA.
EM max.kandula-1@ksc.nasa.gov
NR 30
TC 9
Z9 9
U1 0
U2 6
PU ACOUSTICAL SOC AMER AMER INST PHYSICS
PI MELVILLE
PA STE 1 NO 1, 2 HUNTINGTON QUADRANGLE, MELVILLE, NY 11747-4502 USA
SN 0001-4966
J9 J ACOUST SOC AM
JI J. Acoust. Soc. Am.
PD NOV
PY 2008
VL 124
IS 5
BP EL284
EP EL290
DI 10.1121/1.2987463
PG 7
WC Acoustics; Audiology & Speech-Language Pathology
SC Acoustics; Audiology & Speech-Language Pathology
GA 371MZ
UT WOS:000260836700066
PM 19045679
ER
PT J
AU Yang, Y
Marshak, A
Chiu, JC
Wiscombe, WJ
Palm, SP
Davis, AB
Spangenberg, DA
Nguyen, L
Spinhirne, JD
Minnis, P
AF Yang, Yuekui
Marshak, Alexander
Chiu, J. Christine
Wiscombe, Warren J.
Palm, Stephen P.
Davis, Anthony B.
Spangenberg, Douglas A.
Nguyen, Louis
Spinhirne, James D.
Minnis, Patrick
TI Retrievals of Thick Cloud Optical Depth from the Geoscience Laser
Altimeter System (GLAS) by Calibration of Solar Background Signal
SO JOURNAL OF THE ATMOSPHERIC SCIENCES
LA English
DT Article
ID SATELLITE; INSTRUMENT
AB Laser beams emitted from the Geoscience Laser Altimeter System (GLAS), as well as other spaceborne laser instruments, can only penetrate clouds to a limit of a few optical depths. As a result, only optical depths of thinner clouds (< about 3 for GLAS) are retrieved from the reflected lidar signal. This paper presents a comprehensive study of possible retrievals of optical depth of thick clouds using solar background light and treating GLAS as a solar radiometer. To do so one must first calibrate the reflected solar radiation received by the photon-counting detectors of the GLAS 532-nm channel, the primary channel for atmospheric products. Solar background radiation is regarded as a noise to be subtracted in the retrieval process of the lidar products. However, once calibrated, it becomes a signal that can be used in studying the properties of optically thick clouds. In this paper, three calibration methods are presented: (i) calibration with coincident airborne and GLAS observations, (ii) calibration with coincident Geostationary Operational Environmental Satellite (GOES) and GLAS observations of deep convective clouds, and (iii) calibration from first principles using optical depth of thin water clouds over ocean retrieved by GLAS active remote sensing. Results from the three methods agree well with each other. Cloud optical depth (COD) is retrieved from the calibrated solar background signal using a one-channel retrieval. Comparison with COD retrieved from GOES during GLAS overpasses shows that the average difference between the two retrievals is 24%. As an example, the COD values retrieved from GLAS solar background are illustrated for a marine stratocumulus cloud field that is too thick to be penetrated by the GLAS laser. Based on this study, optical depths for thick clouds will be provided as a supplementary product to the existing operational GLAS cloud products in future GLAS data releases.
C1 [Yang, Yuekui] Univ Maryland, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21201 USA.
[Chiu, J. Christine] Univ Maryland, Joint Ctr Earth Syst Technol, Baltimore, MD 21201 USA.
[Palm, Stephen P.; Spangenberg, Douglas A.] Sci Syst & Applicat Inc, Lanham, MD USA.
[Davis, Anthony B.] Los Alamos Natl Lab, Los Alamos, NM USA.
[Nguyen, Louis; Minnis, Patrick] NASA, Langley Res Ctr, Hampton, VA USA.
RP Yang, Y (reprint author), NASA, Goddard Space Flight Ctr, Code 613-2, Greenbelt, MD 20771 USA.
EM yuekui@umbc.edu
RI Minnis, Patrick/G-1902-2010; Wiscombe, Warren/D-4665-2012; Chiu,
Christine/E-5649-2013; Marshak, Alexander/D-5671-2012; Yang,
Yuekui/B-4326-2015
OI Minnis, Patrick/0000-0002-4733-6148; Wiscombe,
Warren/0000-0001-6844-9849; Chiu, Christine/0000-0002-8951-6913;
FU NASA's ICESat Science Project
FX The authors thank Drs. Tamas Varnai, William Hart, David Doelling, and
Kristine Barbieri for helpful discussions and advice. This work was
supported by NASA's ICESat Science Project.
NR 26
TC 10
Z9 10
U1 3
U2 6
PU AMER METEOROLOGICAL SOC
PI BOSTON
PA 45 BEACON ST, BOSTON, MA 02108-3693 USA
SN 0022-4928
J9 J ATMOS SCI
JI J. Atmos. Sci.
PD NOV
PY 2008
VL 65
IS 11
BP 3513
EP 3527
DI 10.1175/2008JAS2744.1
PG 15
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 374VZ
UT WOS:000261073100009
ER
PT J
AU Zeng, XP
Tao, WK
Lang, S
Hou, AY
Zhang, MH
Simpson, J
AF Zeng, Xiping
Tao, Wei-Kuo
Lang, Stephen
Hou, Arthur Y.
Zhang, Minghua
Simpson, Joanne
TI On the Sensitivity of Atmospheric Ensembles to Cloud Microphysics in
Long-Term Cloud-Resolving Model Simulations
SO JOURNAL OF THE METEOROLOGICAL SOCIETY OF JAPAN
LA English
DT Article
ID SOUTH CHINA SEA; CONVECTIVE SYSTEMS; TOGA COARE; BULK PARAMETERIZATION;
RADIATION INTERACTION; MONSOON EXPERIMENT; SURFACE PROCESSES; DEEP
CONVECTION; ENERGY-BALANCE; PHASE-III
AB Month-long large-scale forcing data from two field campaigns are used to drive a cloud-resolving model (CRM) and produce ensemble simulations of clouds and precipitation. Observational data are then used to evaluate the model results. To improve the model results, a new parameterization of the Bergeron process is proposed that incorporates the number concentration of ice nuclei (IN). Numerical simulations reveal that atmospheric ensembles are sensitive to IN concentration and ice crystal multiplication.
Two- (2D) and three-dimensional (3D) simulations are carried out to address the sensitivity of atmospheric ensembles to model dimensionality. It is found that the ensembles with high IN concentration are more sensitive to dimensionality than those with low IN concentration. Both the analytic solutions of linear dry models and the CRM output show that there are more convective cores with stronger updrafts in 3D simulations than in 2D, which explains the differing sensitivity of the ensembles to dimensionality at different IN concentrations.
C1 [Zeng, Xiping; Tao, Wei-Kuo; Lang, Stephen; Hou, Arthur Y.; Simpson, Joanne] NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA.
[Zeng, Xiping] Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21228 USA.
[Lang, Stephen] Sci Syst & Applicat Inc, Lanham, MD USA.
[Zhang, Minghua] SUNY Stony Brook, Sch Marine & Atmospher Sci, Stony Brook, NY USA.
RP Zeng, XP (reprint author), NASA, Goddard Space Flight Ctr, Atmospheres Lab, Mail Code 613-1, Greenbelt, MD 20771 USA.
EM zeng@agnes.gsfc.nasa.gov
RI Hou, Arthur/D-8578-2012
NR 52
TC 29
Z9 29
U1 1
U2 8
PU METEOROLOGICAL SOC JAPAN
PI TOKYO
PA C/O JAPAN METEOROLOGICAL AGENCY 1-3-4 OTE-MACHI, CHIYODA-KU, TOKYO,
100-0004, JAPAN
SN 0026-1165
EI 2186-9057
J9 J METEOROL SOC JPN
JI J. Meteorol. Soc. Jpn.
PD NOV
PY 2008
VL 86A
SI SI
BP 45
EP 65
PG 21
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 401CU
UT WOS:000262916800005
ER
PT J
AU Cheng, AN
Xu, KM
AF Cheng, Anning
Xu, Kuan-Man
TI Simulation of Boundary-Layer Cumulus and Stratocumulus Clouds Using a
Cloud-Resolving Model with Low- and Third-order Turbulence Closures
SO JOURNAL OF THE METEOROLOGICAL SOCIETY OF JAPAN
LA English
DT Article
ID LARGE-EDDY SIMULATION; PROBABILITY DENSITY-FUNCTIONS; TRADE-WIND CUMULI;
PDF-BASED MODEL; PART I; MOIST CONVECTION; UNIFIED PARAMETERIZATION;
TRANSITION; SCALE; SENSITIVITY
AB The effects of subgrid-scale (SGS) condensation and transport become more important as the grid spacings increase from those typically used in large-eddy simulation (LES) to those typically used in cloud-resolving models (CRMs). Incorporation of these SGS effects can be achieved by a joint probability density function approach that utilizes higher-order moments of thermodynamic and dynamic variables. This study examines how well shallow cumulus and stratocumulus clouds are simulated by two versions of a CRM implemented with low-order (1.5-order) and third-order turbulence closures (LOC and TOC). Resolution sensitivities of the closure are studied by refining the grid spacing from control simulation (with standard CRM grids of 4 km) to simulations with much finer meshes in the horizontal.
In our simulations cumulus clouds are mostly produced through SGS transport processes while stratocumulus clouds are produced through both SGS and resolved-scale processes in the TOC version of the CRM at standard resolution. In contrast, the LOC version of the CRM requires resolved-scale circulations to produce both cumulus and stratocumulus clouds, as SGS transports within cloud layer remain small in this model. The mean profiles of thermodynamic variables, cloud fraction and liquid water content exhibit significant differences between the two versions of the CRM, with the TOC results agreeing better with the LES than the LOC results. The characteristics, temporal evolution and mean profiles of shallow cumulus and stratocumulus clouds are weakly dependent upon the horizontal grid spacing used in the TOC CRM. However, the ratio of the SGS to resolved-scale fluxes becomes smaller as the horizontal grid spacing decreases. The subcloud-layer fluxes are mostly due to the resolved scales when horizontal grid spacings approach the depth of this layer. The overall results of the TOC simulations suggest that the 1-km grid spacing is a good choice for CRM simulation of shallow cumulus and stratocumulus.
C1 [Xu, Kuan-Man] NASA, Langley Res Ctr, Climate Sci Branch, Hampton, VA 23681 USA.
[Cheng, Anning] Analyt Serv & Mat Inc, Hampton, VA 23666 USA.
RP Xu, KM (reprint author), NASA, Langley Res Ctr, Climate Sci Branch, Mail Stop 420, Hampton, VA 23681 USA.
EM Kuan-Man.Xu@nasa.gov
RI Xu, Kuan-Man/B-7557-2013
OI Xu, Kuan-Man/0000-0001-7851-2629
FU Office of Biological and Environmental Research; U.S. Department of
Energy [DE-Al-02-06ER64183]; NASA Modeling, Analysis and Prediction
Program
FX This work was supported by Office of Biological and Environmental
Research, U.S. Department of Energy as part of the Atmospheric Radiation
Measurement (ARM) Program, under interagency agreement
DE-Al-02-06ER64183 and by NASA Modeling, Analysis and Prediction Program
(Dr. Don Anderson, program manager). The authors would Eke to thank Dr.
Marat Khairoutdinov of Colorado State University for providing the SAM
model codes used in this study. He is also thanked for providing
invaluable advice for coupling the third-order closure with the SAM.
Special thanks are given to Dr. Bjorn Stevens for his constructive
suggestions on the revision of the paper. Drs. Zachary Eitzen and
Takmeng Wong are thanked for reading drafts of this paper.
NR 48
TC 21
Z9 21
U1 0
U2 4
PU METEOROLOGICAL SOC JAPAN
PI TOKYO
PA C/O JAPAN METEOROLOGICAL AGENCY 1-3-4 OTE-MACHI, CHIYODA-KU, TOKYO,
100-0004, JAPAN
SN 0026-1165
EI 2186-9057
J9 J METEOROL SOC JPN
JI J. Meteorol. Soc. Jpn.
PD NOV
PY 2008
VL 86A
SI SI
BP 67
EP 86
PG 20
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 401CU
UT WOS:000262916800006
ER
PT J
AU Bindschadler, R
AF Bindschadler, Robert
TI ICE ON THE EDGE
SO NATURAL HISTORY
LA English
DT Article
C1 NASA, Goddard Space Flight Ctr, Hydrospher & Biospher Sci Lab, Greenbelt, MD USA.
RP Bindschadler, R (reprint author), NASA, Goddard Space Flight Ctr, Hydrospher & Biospher Sci Lab, Greenbelt, MD USA.
NR 0
TC 0
Z9 0
U1 1
U2 1
PU NATURAL HISTORY MAGAZINE
PI NEW YORK
PA 36 WEST 25TH STREET, FIFTH FLOOR, NEW YORK, NY 10010 USA
SN 0028-0712
J9 NAT HIST
JI Nat. Hist.
PD NOV
PY 2008
VL 117
IS 9
BP 28
EP 33
PG 6
WC Biodiversity Conservation; Ecology
SC Biodiversity & Conservation; Environmental Sciences & Ecology
GA 391BO
UT WOS:000262207900013
ER
PT J
AU McCleese, DJ
Schofield, JT
Taylor, FW
Abdou, WA
Aharonson, O
Banfield, D
Calcutt, SB
Heavens, NG
Irwin, PGJ
Kass, DM
Kleinbohl, A
Lawson, WG
Leovy, CB
Lewis, SR
Paige, DA
Read, PL
Richardson, MI
Teanby, N
Zurek, RW
AF McCleese, D. J.
Schofield, J. T.
Taylor, F. W.
Abdou, W. A.
Aharonson, O.
Banfield, D.
Calcutt, S. B.
Heavens, N. G.
Irwin, P. G. J.
Kass, D. M.
Kleinboehl, A.
Lawson, W. G.
Leovy, C. B.
Lewis, S. R.
Paige, D. A.
Read, P. L.
Richardson, M. I.
Teanby, N.
Zurek, R. W.
TI Intense polar temperature inversion in the middle atmosphere on Mars
SO NATURE GEOSCIENCE
LA English
DT Article
ID GENERAL-CIRCULATION MODEL; MARTIAN ATMOSPHERE; DUST STORMS; SIMULATION;
MARINER-9; DATABASE; SURFACE; HAZES; ICE
AB Current understanding of weather, climate and global atmospheric circulation on Mars is incomplete, in particular at altitudes above about 30 km. General circulation models for Mars(1-6) are similar to those developed for weather and climate forecasting on Earth and require more martian observations to allow testing and model improvements. However, the available measurements of martian atmospheric temperatures, winds, water vapour and airborne dust are generally restricted to the region close to the surface and lack the vertical resolution and global coverage that is necessary to shed light on the dynamics of Mars' middle atmosphere at altitudes between 30 and 80 km ( ref. 7). Here we report high-resolution observations from the Mars Climate Sounder instrument(8) on the Mars Reconnaissance Orbiter(9). These observations show an intense warming of the middle atmosphere over the south polar region in winter that is at least 10-20 K warmer than predicted by current model simulations. To explain this finding, we suggest that the atmospheric downwelling circulation over the pole, which is part of the equator-to-poleHadley circulation, may be as much as 50% more vigorous than expected, with consequences for the cycles of water, dust and CO2 that regulate the present-day climate on Mars.
C1 [McCleese, D. J.; Schofield, J. T.; Abdou, W. A.; Kass, D. M.; Kleinboehl, A.; Zurek, R. W.] CALTECH, Jet Prop Lab, Pasadena, CA 91103 USA.
[Taylor, F. W.; Calcutt, S. B.; Irwin, P. G. J.; Read, P. L.; Teanby, N.] Univ Oxford, Dept Phys, Clarendon Lab, Oxford OX1 3PU, England.
[Aharonson, O.; Lawson, W. G.; Richardson, M. I.] CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91105 USA.
[Banfield, D.] Cornell Univ, Dept Astron, Ithaca, NY 14850 USA.
[Leovy, C. B.] Univ Washington, Dept Atmospher Sci, Seattle, WA 98101 USA.
[Lewis, S. R.] Open Univ, Dept Phys & Astron, Milton Keynes MK7 6AA, Bucks, England.
[Paige, D. A.] Univ Calif Los Angeles, Dept Earth & Space Sci, Los Angeles, CA 90024 USA.
RP McCleese, DJ (reprint author), CALTECH, Jet Prop Lab, Pasadena, CA 91103 USA.
EM Daniel.J.McCleese@jpl.nasa.gov; fwt@atm.ox.ac.uk
OI Calcutt, Simon/0000-0002-0102-3170; Banfield, Don/0000-0003-2664-0164;
Teanby, Nicholas/0000-0003-3108-5775; Heavens,
Nicholas/0000-0001-7654-503X; Irwin, Patrick/0000-0002-6772-384X; Lewis,
Stephen/0000-0001-7237-6494
FU Science, Technology and Facilities Council
FX The authors acknowledge J. Shirley, C. Backus, T. Pavlicek and E. Sayfi
for their contribution to the acquisition and analysis of MCS data. The
research described in this letter was carried out at the Jet Propulsion
Laboratory, California Institute of Technology, under a contract with
the National Aeronautics and Space Administration and in the UK with the
support of the Science, Technology and Facilities Council.
NR 30
TC 43
Z9 43
U1 0
U2 6
PU NATURE PUBLISHING GROUP
PI NEW YORK
PA 75 VARICK ST, 9TH FLR, NEW YORK, NY 10013-1917 USA
SN 1752-0894
EI 1752-0908
J9 NAT GEOSCI
JI Nat. Geosci.
PD NOV
PY 2008
VL 1
IS 11
BP 745
EP 749
DI 10.1038/ngeo332
PG 5
WC Geosciences, Multidisciplinary
SC Geology
GA 374DU
UT WOS:000261023700011
ER
PT J
AU Martin, W
Baross, J
Kelley, D
Russell, MJ
AF Martin, William
Baross, John
Kelley, Deborah
Russell, Michael J.
TI Hydrothermal vents and the origin of life
SO NATURE REVIEWS MICROBIOLOGY
LA English
DT Review
ID MID-ATLANTIC RIDGE; ANAEROBIC METHANE OXIDATION; SULFATE-REDUCING
BACTERIA; ENERGY-CONSERVATION; METHANOGENIC ARCHAEA; ACETOGENIC
BACTERIA; OXIDIZING ARCHAEA; ORGANIC-COMPOUNDS; CARBON FIXATION; MARINE
SEDIMENT
AB Submarine hydrothermal vents are geochemically reactive habitats that harbour rich microbial communities. There are striking parallels between the chemistry of the H(2)-CO(2) redox couple that is present in hydrothermal systems and the core energy metabolic reactions of some modern prokaryotic autotrophs. The biochemistry of these autotrophs might, in turn, harbour clues about the kinds of reactions that initiated the chemistry of life. Hydrothermal vents thus unite microbiology and geology to breathe new life into research into one of biology's most important questions - what is the origin of life?
C1 [Martin, William] Univ Dusseldorf, Inst Bot 3, D-40225 Dusseldorf, Germany.
[Baross, John; Kelley, Deborah] Univ Washington, Sch Oceanog, Seattle, WA 98195 USA.
[Russell, Michael J.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Martin, W (reprint author), Univ Dusseldorf, Inst Bot 3, D-40225 Dusseldorf, Germany.
EM w.martin@uni-duesseldorf.de
RI Martin, William/C-5680-2008; Martin, William /O-5446-2015
OI Martin, William /0000-0003-1478-6449
FU National Science Foundation [OCE-0137206]; National Oceanic and
Atmospheric Administration Office of Exploration; NASA Astrobiology
Institute; government of New Zealand; Deutsche Forschungsgemeinschaft
FX We thank J. F. Allen, N. Lane and C. Schmidt for comments. M. J. R. is
supported by the Jet Propulsion Laboratory, California Institute of
Technology, through a contract from the National Aeronautics and Space
Administration. D. K. and J. B. are supported by a grant from the
National Science Foundation (grant number OCE-0137206) and a grant from
the National Oceanic and Atmospheric Administration Office of
Exploration. J. B. received additional support from the NASA
Astrobiology Institute through the Cornegie Geophysical Institute. W. M.
is supported, in part, by a Julius-von-Haast Fellowship from the
government of New Zealand and by the Deutsche Forschungsgemeinschaft.
NR 106
TC 291
Z9 313
U1 65
U2 439
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 1740-1526
J9 NAT REV MICROBIOL
JI Nat. Rev. Microbiol.
PD NOV
PY 2008
VL 6
IS 11
BP 805
EP 814
DI 10.1038/nrmicro1991
PG 10
WC Microbiology
SC Microbiology
GA 361HK
UT WOS:000260118500010
PM 18820700
ER
PT J
AU Sarkar, P
Sarkar, S
Ramesh, V
Kim, H
Barnes, S
Kulkarni, A
Hall, JC
Wilson, BL
Thomas, RL
Pellis, NR
Ramesh, GT
AF Sarkar, Poonam
Sarkar, Shubhashish
Ramesh, Vani
Kim, Helen
Barnes, Stephen
Kulkarni, Anil
Hall, Joseph C.
Wilson, Bobby L.
Thomas, Renard L.
Pellis, Neal R.
Ramesh, Govindarajan T.
TI Proteomic analysis of mouse hypothalamus under simulated microgravity
SO NEUROCHEMICAL RESEARCH
LA English
DT Article
DE brain; hypothalamus; microgravity
ID ALZHEIMERS-DISEASE; OXIDATIVE STRESS; GENE-EXPRESSION; SPACE-FLIGHT;
BRAIN; IDENTIFICATION; RATS; DEHYDROGENASE; MITOCHONDRIA; SPACEFLIGHT
AB Exposure to altered microgravity during space travel induces changes in the brain and these are reflected in many of the physical behavior seen in the astronauts. The vulnerability of the brain to microgravity stress has been reviewed and reported. Identifying microgravity-induced changes in the brain proteome may aid in understanding the impact of the microgravity environment on brain function. In our previous study we have reported changes in specific proteins under simulated microgravity in the hippocampus using proteomics approach. In the present study the profiling of the hypothalamus region in the brain was studied as a step towards exploring the effect of microgravity in this region of the brain. Hypothalamus is the critical region in the brain that strictly controls the pituitary gland that in turn is responsible for the secretion of important hormones. Here we report a 2-dimensional gel electrophoretic analysis of the mouse hypothalamus in response to simulated microgravity. Lowered glutathione and differences in abundance expression of seven proteins were detected in the hypothalamus of mice exposed to microgravity. These changes included decreased superoxide dismutase-2 (SOD-2) and increased malate dehydrogenase and peroxiredoxin-6, reflecting reduction of the antioxidant system in the hypothalamus. Taken together the results reported here indicate that oxidative imbalance occurred in the hypothalamus in response to simulated microgravity.
C1 [Hall, Joseph C.; Ramesh, Govindarajan T.] Norfolk State Univ, Ctr Biotechnol & Biomed Sci, Dept Biol, Mol Toxicol Lab, Norfolk, VA 23504 USA.
[Sarkar, Poonam; Kim, Helen; Barnes, Stephen] Univ Alabama, Dept Pharmacol & Toxicol, Birmingham, AL 35294 USA.
[Sarkar, Shubhashish; Wilson, Bobby L.; Thomas, Renard L.] Texas So Univ, NASA URC, Houston, TX 77004 USA.
[Ramesh, Vani; Kulkarni, Anil] Univ Texas Houston, Dept Surg, Houston, TX 77030 USA.
[Pellis, Neal R.] NASA JSC, Cellular Biotechnol Program, Houston, TX 77058 USA.
RP Ramesh, GT (reprint author), Norfolk State Univ, Ctr Biotechnol & Biomed Sci, Dept Biol, Mol Toxicol Lab, Norfolk, VA 23504 USA.
EM gtramesh@nsu.edu
FU NASA [NCC 9-165, NSTI NNA06CB14H]; NIH-NCMHHD [1P20MD001822]
FX This work was supported by NASA funding NCC 9-165; NIH-NCMHHD
1P20MD001822; NASA NSTI NNA06CB14H.
NR 26
TC 22
Z9 26
U1 1
U2 6
PU SPRINGER/PLENUM PUBLISHERS
PI NEW YORK
PA 233 SPRING ST, NEW YORK, NY 10013 USA
SN 0364-3190
J9 NEUROCHEM RES
JI Neurochem. Res.
PD NOV
PY 2008
VL 33
IS 11
BP 2335
EP 2341
DI 10.1007/s11064-008-9738-1
PG 7
WC Biochemistry & Molecular Biology; Neurosciences
SC Biochemistry & Molecular Biology; Neurosciences & Neurology
GA 352GG
UT WOS:000259483300021
PM 18473167
ER
PT J
AU Schodlok, MP
Wenzel, M
Schroter, JG
Hellmer, HH
AF Schodlok, Michael P.
Wenzel, Manfred
Schroeter, Jens G.
Hellmer, Hartmut H.
TI Regional and global effects of southern ocean constraints in a global
model
SO OCEAN DYNAMICS
LA English
DT Article
DE Weddell Sea; Ross Sea; Numerical modelling; State estimation; Global
ocean; Adjoint method
ID ANTARCTIC BOTTOM WATER; WEDDELL SEA; ROSS-SEA; CIRCULATION MODEL;
HEAT-TRANSPORT; INDIAN-OCEAN; VARIABILITY; ORIGIN; MASSES; ASSIMILATION
AB Global ocean circulation models do not usually take high-latitude processes into account in an adequate form due to a limited model domain or insufficient resolution. Without the processes in key areas contributing to the lower part of the global thermohaline circulation, the characteristics and flow of deep and bottom waters often remain unrealistic in these models. In this study, various sections of the Bremerhaven Regional Ice Ocean Simulation model results are combined with a global inverse model by using temperature, salinity, and velocity constraints for the Hamburg Large Scale Geostrophic ocean general circulation model. The differences between the global model with and without additional constraints from the regional model demonstrate that the Weddell Sea circulation exerts a significant influence on the course of the Antarctic Circumpolar Current with consequences for Southern Ocean water mass characteristics and the spreading of deep and bottom waters in the South Atlantic. The influence of the Ross Sea is found to be less important in terms of global influences. However, regional changes in the Pacific sector of the Southern Ocean are found to be of Ross Sea origin. The additional constraints change the hydrographic conditions of the global model in the vicinity of the Antarctic Circumpolar Current in such a way that transport values, e.g., in Drake Passage no longer need to be prescribed to obtain observed transports. These changes not only improve the path and transport of the Antarctic Circumpolar Current but affect the meso- and large-scale circulation. With a higher (lower) mean Drake Passage transport, the mean Weddell Gyre transport is lower (higher). Furthermore, an increase (decrease) in the Antarctic Circumpolar Current leads to a decrease (increase) of the circum-Australian flow, i.e., a decrease (increase) of the Indonesian Throughflow.
C1 [Schodlok, Michael P.; Wenzel, Manfred; Schroeter, Jens G.; Hellmer, Hartmut H.] Alfred Wegener Inst Polar & Marine Res, D-2850 Bremerhaven, Germany.
RP Schodlok, MP (reprint author), CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA.
EM Michael.P.Schodlok@jpl.nasa.gov
NR 53
TC 2
Z9 2
U1 0
U2 4
PU SPRINGER HEIDELBERG
PI HEIDELBERG
PA TIERGARTENSTRASSE 17, D-69121 HEIDELBERG, GERMANY
SN 1616-7341
EI 1616-7228
J9 OCEAN DYNAM
JI Ocean Dyn.
PD NOV
PY 2008
VL 58
IS 3-4
BP 155
EP 168
DI 10.1007/s10236-008-0143-8
PG 14
WC Oceanography
SC Oceanography
GA 371NZ
UT WOS:000260839300001
ER
PT J
AU Cullings, K
Ishkhanova, G
Henson, J
AF Cullings, Ken
Ishkhanova, Galina
Henson, Joan
TI Defoliation effects on enzyme activities of the ectomycorrhizal fungus
Suillus granulatus in a Pinus contorta (lodgepole pine) stand in
Yellowstone National Park
SO OECOLOGIA
LA English
DT Article
DE ectomycorrhizae; Suillus granulatus; enzymes; defoliation; Yellowstone
ID ELEVATED ATMOSPHERIC CO2; PHANEROCHAETE-CHRYSOSPORIUM; MYCORRHIZAL
COLONIZATION; EXTRACELLULAR PROTEASES; AXENIC-CULTURE; PINYON PINES;
NITROGEN; LITTER; LIGNIN; FOREST
AB Ectomycorrhizal (EM) basidiomycete fungi are obligate mutualists of pines and hardwoods that receive fixed C from the host tree. Though they often share most recent common ancestors with wood-rotting fungi, it is unclear to what extent EM fungi retain the ability to express enzymes that break down woody substrates. In this study, we tested the hypothesis that the dominant EM fungus in a pure pine system retains the ability to produce enzymes that break down woody substrates in a natural setting, and that this ability is inducible by reduction of host photosynthetic potential via partial defoliation. To achieve this, pines in replicate blocks were defoliated 50% by needle removal, and enzyme activities were measured in individual EM root tips that had been treated with antibiotics to prevent possible bacterial activity. Results indicate that the dominant EM fungal species (Suillus granulatus) expressed all enzymes tested (endocellulase D-glucosidase, laccase, manganese peroxidase, lignin peroxidase, phosphatase and protease), and that activities of these enzymes increased significantly (P < 0.001) in response to defoliation. Thus, this EM fungus (one of the more specialized mutualists of pine) has the potential to play a significant role in C, N and P cycling in this forested ecosystem. Therefore, many above-ground factors that reduce photosynthetic potential or divert fixed C from roots may have wide-reaching ecosystem effects.
C1 [Cullings, Ken; Ishkhanova, Galina] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
[Henson, Joan] Montana State Univ, Dept Microbiol, Bozeman, MT 59717 USA.
RP Cullings, K (reprint author), NASA, Ames Res Ctr, MS 239-11, Moffett Field, CA 94035 USA.
EM cullings1@earthlink.net; jhenson@montana.edu
FU NSF [0211848]
FX This work was supported by an NSF grant to Henson and Cullings (NSF
Ecology 0211848). We thank the Yellowstone Center for Resources for
logistical support.
NR 52
TC 30
Z9 31
U1 2
U2 34
PU SPRINGER
PI NEW YORK
PA 233 SPRING ST, NEW YORK, NY 10013 USA
SN 0029-8549
J9 OECOLOGIA
JI Oecologia
PD NOV
PY 2008
VL 158
IS 1
BP 77
EP 83
DI 10.1007/s00442-008-1119-6
PG 7
WC Ecology
SC Environmental Sciences & Ecology
GA 357AX
UT WOS:000259819800008
PM 18679722
ER
PT J
AU Bro-Jorgensen, J
Brown, ME
Pettorelli, N
AF Bro-Jorgensen, Jakob
Brown, Molly E.
Pettorelli, Nathalie
TI Using the satellite-derived normalized difference vegetation index
(NDVI) to explain ranging patterns in a lek-breeding antelope: the
importance of scale
SO OECOLOGIA
LA English
DT Article
DE satellite vegetation data; mating behaviour; territoriality;
antipredator behaviour; ungulate
ID NET PRIMARY PRODUCTION; DAMALISCUS-LUNATUS; WILDEBEEST MIGRATION; MATING
STRATEGIES; TOPI BULLS; SERENGETI; LEKKING; BEHAVIOR; HOTSPOTS; IMPACT
AB Lek-breeding species are characterized by a negative association between territorial resource availability and male mating success; however, the impact of resources on the overall distribution patterns of the two sexes in lek systems is not clear. The normalized difference vegetation index (NDVI) has recently emerged as a powerful proxy measure for primary productivity, allowing the links between the distributions of animals and resources to be explored. Using NDVI at four spatial resolutions, we here investigate how the distribution of the two sexes in a lek-breeding population of topi antelopes relates to resource abundance before and during the rut. We found that in the dry season preceding the rut, topi density correlated positively with NDVI at the large, but not the fine, scale. This suggests that before the rut, when resources were relatively scant, topi preferred pastures where green grass was widely abundant. The pattern was less pronounced in males, suggesting that the need for territorial attendance prevents males from tracking resources as freely as females do. During the rut, which occurs in the wet season, both male and female densities correlated negatively with NDVI at the fine scale. At this time, resources were generally plentiful and the results suggest that, rather than by resource maximization, distribution during the rut was determined by benefits of aggregating on relatively resource-poor leks for mating, and possibly antipredator, purposes. At the large scale, no correlation between density and NDVI was found during the rut in either sex, which can be explained by leks covering areas too small to be reflected at this resolution. The study illustrates that when investigating spatial organization, it is important: (1) to choose the appropriate analytic scale, and (2) to consider behavioural as well as strictly ecological factors.
C1 [Bro-Jorgensen, Jakob; Pettorelli, Nathalie] Zool Soc London, Inst Zool, London NW1 4RY, England.
[Bro-Jorgensen, Jakob] Univ Jyvaskyla, Dept Biol & Environm Sci, Jyvaskyla, Finland.
[Brown, Molly E.] NASA, Goddard Space Flight Ctr, SSAI, Greenbelt, MD 20771 USA.
RP Bro-Jorgensen, J (reprint author), Zool Soc London, Inst Zool, Regents Pk, London NW1 4RY, England.
EM jb504@cam.ac.uk
RI Brown, Molly/E-2724-2010; Brown, Molly/M-5146-2013
OI Brown, Molly/0000-0001-7384-3314; Brown, Molly/0000-0001-7384-3314
FU Danish Research Agency; Marie Curie Intra-European
FX We are grateful to Paul E. Loth and two anonymous reviewers for their
comments, to Mada Hotels for logistic support, and to the Ministry of
Science and Technology in Kenya, Narok County Council, the Senior Warden
of Masai Mara National Reserve and Kenya Wildlife Service for permission
to do Weld work. This research was supported by the Danish Research
Agency and a Marie Curie Intra-European Fellowship within the 6th
European Community Framework Programme to Jakob Bro-Jorgensen.
NR 36
TC 19
Z9 20
U1 0
U2 24
PU SPRINGER
PI NEW YORK
PA 233 SPRING ST, NEW YORK, NY 10013 USA
SN 0029-8549
J9 OECOLOGIA
JI Oecologia
PD NOV
PY 2008
VL 158
IS 1
BP 177
EP 182
DI 10.1007/s00442-008-1121-z
PG 6
WC Ecology
SC Environmental Sciences & Ecology
GA 357AX
UT WOS:000259819800017
PM 18670791
ER
PT J
AU Pinto, N
Keitt, TH
AF Pinto, Naiara
Keitt, Timothy H.
TI Scale-dependent responses to forest cover displayed by frugivore bats
SO OIKOS
LA English
DT Article
ID HOME-RANGE SIZE; ARTIBEUS-JAMAICENSIS; FRAGMENTED LANDSCAPE; SPECIES
RICHNESS; FRENCH-GUIANA; RAIN-FOREST; HABITAT; BRAZIL; ECOSYSTEM;
ECOLOGY
AB Despite vast evidence of species turnover displayed by Neotropical bat communities in response to forest fragmentation, the exact shape of the relationship between fragment area and abundance for individual bat species is still unclear. Bats' ample variation in diet, morphology, and movement behaviour can potentially influence species' perception of the landscape. Thus, studies describing fragment area at a single spatial scale may fail to capture the amount of forest available from the perspective of individual bat species. In the present paper, we study the influence of forest cover on bats inhabiting a fragmented forest in Mexico, focusing on some of the most common frugivore species: Artibeus jamaicensis, Carollia spp. (C. brevicauda/C. perspicillata) and Sturnira spp. (S. lilium/S. ludovici).
We quantified forest cover at scales ranging from 50 to 2000 m, and measured the influence of forest cover on bat capture success, a surrogate for abundance. The three species displayed positive and significant scale-dependent associations with forest cover. Abundance of A. jamaicensis increased with forest cover measured at scales ranging between 500 and 2000 m, while Carollia spp. responded more strongly to variation in forest cover measured at scales 100-500 m. For Sturnira spp., abundance was a function of presence of creeks near mist-netting sites, and amount of secondary forest present at a 200 m scale. The observed variation in responses to forest cover can be explained in light of interspecific differences in diet, home range, and body size. Our results illustrate a method for measuring the effect of forest fragmentation on mobile species and suggest that changes in abundance in fragmented landscapes emerge from the interaction between species' traits and landscape structure.
C1 [Pinto, Naiara; Keitt, Timothy H.] Univ Texas Austin, Sect Integrat Biol, Austin, TX 78712 USA.
[Pinto, Naiara] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Pinto, N (reprint author), Univ Texas Austin, Sect Integrat Biol, Austin, TX 78712 USA.
EM naiara@mail.utexas.edu
FU Dorothea Bennet Memorial Graduate Fellowship
FX The authors would like to thank A. Estrada and M. Ricker for support at
the Los Tuxtlas Biological Station, E. Sanchez Vazquez, D. Gallegos
Castillo and M. Leoni for assistance in the field, R. Coates for
assistance identifying species, and C. Brooks and T. Fuller for comments
on the manuscript. This work was funded by the Exploration Fund and the
Dorothea Bennet Memorial Graduate Fellowship.
NR 38
TC 17
Z9 18
U1 2
U2 22
PU BLACKWELL PUBLISHING
PI OXFORD
PA 9600 GARSINGTON RD, OXFORD OX4 2DQ, OXON, ENGLAND
SN 0030-1299
J9 OIKOS
JI Oikos
PD NOV
PY 2008
VL 117
IS 11
BP 1725
EP 1731
DI 10.1111/j.1600-0706.2008.16495.x
PG 7
WC Ecology
SC Environmental Sciences & Ecology
GA 366QY
UT WOS:000260499700014
ER
PT J
AU Francis Simpanya, M
Ansari, RR
Leverenz, V
Giblin, FJ
AF Francis Simpanya, M.
Ansari, Rafat R.
Leverenz, Victor
Giblin, Frank J.
TI Measurement of Lens Protein Aggregation in Vivo Using Dynamic Light
Scattering in a Guinea Pig/UVA Model for Nuclear Cataract
SO PHOTOCHEMISTRY AND PHOTOBIOLOGY
LA English
DT Article
ID BEAVER DAM EYE; SUNLIGHT EXPOSURE; UVA IRRADIATION; SINGLET OXYGEN; PIG
LENS; ULTRAVIOLET-RADIATION; HYDROGEN-PEROXIDE; OXIDATIVE STRESS; RABBIT
LENS; AGING LENS
AB The role of UVA radiation in the formation of human nuclear cataract is not well understood. We have previously shown that exposing guinea pigs for 5 months to a chronic low level of UVA light produces increased lens nuclear light scattering and elevated levels of protein disulfide. Here we have used the technique of dynamic light scattering (DLS) to investigate lens protein aggregation in vivo in the guinea pig/UVA model. DLS size distribution analysis conducted at the same location in the lens nucleus of control and UVA-irradiated animals showed a 28% reduction in intensity of small diameter proteins in experimental lenses compared with controls (P < 0.05). In addition, large diameter proteins in UVA-exposed lens nuclei increased five-fold in intensity compared to controls (P < 0.05). The UVA-induced increase in apparent size of lens nuclear small diameter proteins was three-fold (P < 0.01), and the size of large diameter aggregates was more than four-fold in experimental lenses compared with controls. The diameter of crystallin aggregates in the UVA-irradiated lens nucleus was estimated to be 350 nm, a size able to scatter light. No significant changes in protein size were detected in the anterior cortex of UVA-irradiated lenses. It is presumed that the presence of a UVA chromophore in the guinea pig lens (NADPH bound to zeta crystallin), as well as traces of oxygen, contributed to UVA-induced crystallin aggregation. The results indicate a potentially harmful role for UVA light in the lens nucleus. A similar process of UVA-irradiated protein aggregation may take place in the older human lens nucleus, accelerating the formation of human nuclear cataract.
C1 [Francis Simpanya, M.; Leverenz, Victor; Giblin, Frank J.] Oakland Univ, Eye Res Inst, Rochester, MI USA.
[Ansari, Rafat R.] NASA, Glenn Res Ctr, Cleveland, OH USA.
RP Giblin, FJ (reprint author), Oakland Univ, Eye Res Inst, Rochester, MI USA.
EM giblin@oakland.edu
FU NASA [NAG3-2892]; NIH [EY EY02027, EY 014803]
FX This work was supported in part by NASA Award NAG3-2892, NIH EY EY02027
and NIH EY 014803. We thank James King of NASA for help with in vivo
analysis of the guinea pig lenses by DLS, and Li-Ren Lin, M. D., for
slit-lamp examination of the eyes of the animals. We appreciate the
professional long-term care of the animals provided by Cliff Snitgen,
Janet Schofding and Joyce Schram.
NR 69
TC 1
Z9 1
U1 1
U2 6
PU WILEY-BLACKWELL PUBLISHING, INC
PI MALDEN
PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA
SN 0031-8655
J9 PHOTOCHEM PHOTOBIOL
JI Photochem. Photobiol.
PD NOV-DEC
PY 2008
VL 84
IS 6
BP 1589
EP 1595
DI 10.1111/j.1751-1097.2008.00390.x
PG 7
WC Biochemistry & Molecular Biology; Biophysics
SC Biochemistry & Molecular Biology; Biophysics
GA 374ZC
UT WOS:000261081200040
ER
PT J
AU Niepold, F
Herring, D
McConville, D
AF Niepold, Frank
Herring, David
McConville, David
TI THE ROLE OF NARRATIVE AND GEOSPATIAL VISUALIZATION IN FOSTERING CLIMATE
LITERATE CITIZENS
SO PHYSICAL GEOGRAPHY
LA English
DT Article
DE climate; climate change; global warming; Earth science; climate
literacy; science literacy; education; visualization; storytelling
ID SCIENCE; CONSENSUS
AB The advent of the Internet and evolutionary advances in geospatial data browsers, virtual globes, and immersive visualization displays have significantly increased the potential for a more climate science literate public. At the same time, space-based Earth-observing agencies like NASA and NOAA in the United States have geometrically increased the volume of data they collect everyday over the entire globe. Fortunately, Moore's Law held true during that same time span, so that the processing capacity of modern computers has exponentially increased, enabling scientists to collect, process, and share these data with increasing efficiency and turnaround time. Since 1980, the combination of these technologies has substantially increased public access to cutting-edge climate science data and information. But has there been a corresponding increase in public climate science literacy? Has there also been a corresponding improvement in public attitudes and opinions about climate science research? In this paper, we review current research about public awareness, understanding, and opinions about existing climate research. We also review several initiatives that our agencies (NASA and NOAA) have taken to help improve climate science literacy. Our research coincides with others' findings in, suggesting that it is possible to improve climate science literacy and positive attitudes about modern climate research, via particular methods of communication. We conclude with a call for collaborators to work with NASA and NOAA in the assembly of a "synergetic" new climate science communications and education infrastructure, as articulated by the late R. Buckminster Fuller, in which the whole works together much more effectively than the sum of the individual parts. We argue that the inherent difficulty of improving public climate science literacy, much less addressing the problems that stem from illiteracy and negative attitudes toward climate science, render the problem too great for any one agency or effort to tackle alone. Addressing the problem synergistically through transdisciplinary collaborations increases the potential for success while enriching all those involved in climate literacy efforts.
C1 [Niepold, Frank] NOAA, UCAR Climate Program Off, Natl Ocean & Atmospher Adm, Silver Spring, MD 20910 USA.
[Herring, David] NASA, Goddard Space Flight Ctr, Div Earth Sci, Greenbelt, MD 20771 USA.
[McConville, David] Elumenati, Asheville, NC 28806 USA.
RP Niepold, F (reprint author), NOAA, UCAR Climate Program Off, Natl Ocean & Atmospher Adm, 1315 East West Highway,SSMC 3,Room 12117, Silver Spring, MD 20910 USA.
NR 27
TC 3
Z9 3
U1 3
U2 26
PU BELLWETHER PUBL LTD
PI COLUMBIA
PA 8640 GUILFORD RD, STE 200, COLUMBIA, MD 21046 USA
SN 0272-3646
J9 PHYS GEOGR
JI Phys. Geogr.
PD NOV-DEC
PY 2008
VL 29
IS 6
BP 529
EP 544
DI 10.2747/0272-3646.29.6.529
PG 16
WC Environmental Sciences; Geography, Physical; Geosciences,
Multidisciplinary; Meteorology & Atmospheric Sciences
SC Environmental Sciences & Ecology; Physical Geography; Geology;
Meteorology & Atmospheric Sciences
GA 423HW
UT WOS:000264488400005
ER
PT J
AU Smith, DD
Chang, H
Arissian, L
Diels, JC
AF Smith, David D.
Chang, Hongrok
Arissian, L.
Diels, J. C.
TI Dispersion-enhanced laser gyroscope
SO PHYSICAL REVIEW A
LA English
DT Article
ID ELECTROMAGNETICALLY INDUCED TRANSPARENCY; MODULATION SPECTROSCOPY;
PROPAGATION; LIGHT; MODE
AB We analyze the effect of a highly dispersive element placed inside a modulated optical cavity on the frequency and amplitude of the output modulation to determine the conditions for enhanced gyroscopic sensitivities. The element is treated as both a phase and amplitude filter, and the time dependence of the cavity field is considered. Both atomic gases (two level and multilevel) and optical resonators (single and coupled) are considered and compared as dispersive elements. We find that it is possible to simultaneously enhance the gyro scale factor sensitivity and suppress the dead band by using an element with anomalous dispersion that has greater loss at the carrier frequency than at the sideband frequencies, i.e., an element that simultaneously pushes and intensifies the perturbed cavity modes, e.g. a two-level absorber or an undercoupled optical resonator. The sensitivity enhancement is inversely proportional to the effective group index, becoming infinite at a group index of zero. However, the number of round trips required to reach a steady state also becomes infinite when the group index is zero (or two). For even larger dispersions a steady state cannot be achieved, and nonlinear dynamic effects such as bistability and periodic oscillations are predicted in the gyro response.
C1 [Smith, David D.] NASA, George C Marshall Space Flight Ctr, Spacecraft & Vehicle Syst Dept, Huntsville, AL 35812 USA.
[Smith, David D.; Chang, Hongrok] Univ Alabama, Dept Phys, Huntsville, AL 35899 USA.
[Arissian, L.; Diels, J. C.] Univ New Mexico, Dept Phys & Astron, Albuquerque, NM 87131 USA.
RP Smith, DD (reprint author), NASA, George C Marshall Space Flight Ctr, Spacecraft & Vehicle Syst Dept, EV43, Huntsville, AL 35812 USA.
NR 30
TC 29
Z9 30
U1 0
U2 8
PU AMER PHYSICAL SOC
PI COLLEGE PK
PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA
SN 2469-9926
EI 2469-9934
J9 PHYS REV A
JI Phys. Rev. A
PD NOV
PY 2008
VL 78
IS 5
AR 053824
DI 10.1103/PhysRevA.78.053824
PG 9
WC Optics; Physics, Atomic, Molecular & Chemical
SC Optics; Physics
GA 376XF
UT WOS:000261215600171
ER
PT J
AU Dicus, DA
Repko, WW
Teplitz, VL
AF Dicus, Duane A.
Repko, Wayne W.
Teplitz, V. L.
TI Critical charges on strange quark nuggets and other extended objects
SO PHYSICAL REVIEW D
LA English
DT Article
AB We investigate the behavior of the critical charge for spontaneous pair production, Z(C), defined as the charge at which the total energy of a K-shell electron is E = -m(e), as a function of the radius R of the charge distribution. Our approach is to solve the Dirac equation for a potential V(r) consisting of a spherically symmetrical charge distribution of radius R and a Coulomb tail. For a spherical shell distribution of the type usually associated with color-flavor locked strange quark nuggets, we confirm the relation Z(C) = 0.71R (fm) for sufficiently large R obtained by Madsen, who used an approach based on the Thomas-Fermi model. We also present results for a uniformly charged sphere and again find that Z(C) similar to R for large enough R. Also discussed is the behavior of Z(C) when simple ad hoc modifications are made to the potential for 0 <= r < R.
C1 [Dicus, Duane A.] Univ Texas Austin, Dept Phys, Austin, TX 78712 USA.
[Repko, Wayne W.] Michigan State Univ, Dept Phys & Astron, E Lansing, MI 48824 USA.
[Teplitz, V. L.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
[Teplitz, V. L.] So Methodist Univ, Dept Phys, Dallas, TX 75275 USA.
RP Dicus, DA (reprint author), Univ Texas Austin, Dept Phys, Austin, TX 78712 USA.
EM dicus@physics.utexas.edu; repko@pa.msu.edu;
teplitz@milkyway.gsfc.nasa.gov
FU U.S. Department of Energy [DE-FG03-93ER40757]; National Science
Foundation [PHY-0555544]
FX D. A. D. was supported in part by the U.S. Department of Energy under
Grant No. DE-FG03-93ER40757. W. W. R. was supported in part by the
National Science Foundation under Grant No. PHY-0555544.
NR 9
TC 3
Z9 3
U1 1
U2 1
PU AMER PHYSICAL SOC
PI COLLEGE PK
PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA
SN 1550-7998
J9 PHYS REV D
JI Phys. Rev. D
PD NOV
PY 2008
VL 78
IS 9
AR 094006
DI 10.1103/PhysRevD.78.094006
PG 5
WC Astronomy & Astrophysics; Physics, Particles & Fields
SC Astronomy & Astrophysics; Physics
GA 376WO
UT WOS:000261213900028
ER
PT J
AU Hesse, M
Zenitani, S
Klimas, A
AF Hesse, Michael
Zenitani, Seiji
Klimas, Alex
TI The structure of the electron outflow jet in collisionless magnetic
reconnection
SO PHYSICS OF PLASMAS
LA English
DT Article
DE magnetic reconnection; plasma jets
ID FIELD; SHEET
AB Particle-in-cell simulations and analytic theory are applied to the study of the electron outflow jet in collisionless magnetic reconnection. In these jets, which have also been identified in spacecraft observations, electron flow speeds in thin layers exceed the ExB drift, suggesting that electrons are unmagnetized. In this study, we find the surprising result that the electron flow jets can be explained by a combination of ExB drifts and of diamagnetic effects through the combination of the gradients of particle pressure and of the magnetic field. In a suitably rotated coordinate system, the electron motion is readily decomposed into ExB drift and the motion to support the required current density, consistent with electron gyrotropy. This process appears to be nondissipative.
C1 [Hesse, Michael; Zenitani, Seiji; Klimas, Alex] NASA, Goddard Space Flight Ctr, Space Weather Lab, Greenbelt, MD 20771 USA.
RP Hesse, M (reprint author), NASA, Goddard Space Flight Ctr, Space Weather Lab, Code 674, Greenbelt, MD 20771 USA.
RI Hesse, Michael/D-2031-2012; Zenitani, Seiji/D-7988-2013; NASA MMS,
Science Team/J-5393-2013
OI Zenitani, Seiji/0000-0002-0945-1815; NASA MMS, Science
Team/0000-0002-9504-5214
FU NASA
FX This research was supported by NASA's MMS mission. One of us (S.Z.)
gratefully acknowledges support from NASA's postdoctoral program. The
authors acknowledge helpful comments from Karl Schindler.
NR 14
TC 28
Z9 28
U1 0
U2 1
PU AMER INST PHYSICS
PI MELVILLE
PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1,
MELVILLE, NY 11747-4501 USA
SN 1070-664X
J9 PHYS PLASMAS
JI Phys. Plasmas
PD NOV
PY 2008
VL 15
IS 11
AR 112102
DI 10.1063/1.3006341
PG 5
WC Physics, Fluids & Plasmas
SC Physics
GA 376VZ
UT WOS:000261212400003
ER
PT J
AU Levasseur-Regourd, AC
Zolensky, M
Lasue, J
AF Levasseur-Regourd, A. C.
Zolensky, M.
Lasue, J.
TI Dust in cometary comae: Present understanding of the structure and
composition of dust particles
SO PLANETARY AND SPACE SCIENCE
LA English
DT Article; Proceedings Paper
CT 4th Annual Meeting of the Asia-Oceania-Geosciences-Society
CY JUL 30-AUG 04, 2007
CL Bangkok, THAILAND
SP Asia Oceania Geosci Soc
DE Comet; Dust; Structure; Composition; Polarimetry; Aggregate
ID BOPP C/1995 O1; LIGHT-SCATTERING; HALE-BOPP; ROSETTA MISSION;
SOLAR-SYSTEM; PROGRA(2) EXPERIMENT; INTERPLANETARY DUST;
PHYSICAL-PROPERTIES; DEEP IMPACT; WATER ICE
AB In situ probing of a very few cometary comae has shown that dust particles present a low albedo and it low density, and that they consist of both rocky material and refractory organics. Remote observations of solar light scattered by cometary dust provide information on the properties of dust particles in the coma of a larger set of cornets. The observations of the linear polarization in the coma indicate that the dust particles are irregular, with a size greater (on the average) than about 1 mu m. Besides, they suggest, through numerical and experimental simulations, that both compact grains and fluffy aggregates (with a power law of the size distribution in the -2.6 to -3 range), and both rather transparent silicates and absorbing organics Eire present in the coma. Recent analysis of the cometary dust samples collected by the Stardust mission provide it unique ground truth and confirm, for cornet 81 P/Wild 2, the results from remote sensing observations. Future space missions to comets should, in the next decade, lead to a more precise characterization of the structure and composition of cometary dust particles. (C) 2008 Elsevier Ltd. All rights reserved.
C1 [Levasseur-Regourd, A. C.; Lasue, J.] Univ Paris 06, UPMC, CNRS, IPSL,UMR 7620, F-91371 Verrieres Le Buisson, France.
[Zolensky, M.] KT NASA Johnson Space Ctr, Houston, TX 77058 USA.
RP Levasseur-Regourd, AC (reprint author), Univ Paris 06, UPMC, CNRS, IPSL,UMR 7620, BP 3, F-91371 Verrieres Le Buisson, France.
EM aclr@aerov.jussieu.fr
NR 45
TC 14
Z9 14
U1 0
U2 3
PU PERGAMON-ELSEVIER SCIENCE LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
SN 0032-0633
J9 PLANET SPACE SCI
JI Planet Space Sci.
PD NOV
PY 2008
VL 56
IS 13
SI SI
BP 1719
EP 1724
DI 10.1016/j.pss.2008.08.006
PG 6
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 381QP
UT WOS:000261551300008
ER
PT J
AU Wong, JY
Asnani, VM
AF Wong, J. Y.
Asnani, V. M.
TI Study of the correlation between the performances of lunar vehicle
wheels predicted by the Nepean wheeled vehicle performance model and
test data
SO PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART D-JOURNAL OF
AUTOMOBILE ENGINEERING
LA English
DT Article
DE correlation study; lunar vehicle wheels; simulation models; terrestrial
and extraterrestrial vehicles; tractive performance
ID RIGID WHEELS
AB This paper describes the results of a study of the correlation between the performances of wheels for lunar vehicles predicted using the Nepean wheeled vehicle performance model (NWVPM), developed under the auspices of Vehicle Systems Development Corporation, Ottawa, Canada, and the corresponding test data presented in 'Performance evaluation of wheels for lunar vehicles', Technical Report M-70-2, prepared for George C. Marshall Space Flight Center, National Aeronautics and Space Administration (NASA), USA, by the US Army Engineer Waterways Experiment Station (WES). The NWVPM was originally developed for design and performance evaluation of terrestrial off-road wheeled vehicles. The purpose of this study is to assess the potential of the NWVPM for evaluating wheel candidates for the new generation of extra-terrestrial vehicles. Two versions of a wire-mesh wheel and a hoop-spring wheel, which were considered as candidates for lunar roving vehicles for the NASA Apollo program in the late 1960s, together with a pneumatic wheel were examined in this study. The tractive performances of these wheels and of a 4 x 4 test vehicle with the pneumatic wheels on air-dry sand were predicted using the NWVPM and compared with the corresponding test data obtained under Earth's gravity and previously documented in the above-named report. While test data on wheel or vehicle performances obtained under Earth's gravity may not necessarily be representative of those on extra-terrestrial bodies, because of the differences in gravity and in environmental conditions, such as atmospheric pressure, it is still a valid approach to use test data obtained under Earth's gravity to evaluate the predictive capability of the NWVPM and its potential applications to predicting wheel or wheeled rover performances on extra-terrestrial bodies. Results of this study show that, using the ratio (P(20)/W) of the drawbar pull to normal load at 20 per cent slip as a performance indicator, there is a reasonable correlation between the predictions and experimental data. This indicates that the NWVPM has the potential as an engineering tool for evaluating wheel candidates for a future generation of extra-terrestrial vehicles, provided that appropriate input data are available.
C1 [Wong, J. Y.] Vehicle Syst Dev Corp, Ottawa, ON K2E 7J7, Canada.
[Asnani, V. M.] NASA, Glenn Res Ctr, Mech Components Branch, Cleveland, OH USA.
RP Wong, JY (reprint author), Vehicle Syst Dev Corp, 49 Fifeshire Crescent, Ottawa, ON K2E 7J7, Canada.
EM jwong@connect.carleton.ca
NR 20
TC 14
Z9 14
U1 0
U2 6
PU PROFESSIONAL ENGINEERING PUBLISHING LTD
PI WESTMINISTER
PA 1 BIRDCAGE WALK, WESTMINISTER SW1H 9JJ, ENGLAND
SN 0954-4070
J9 P I MECH ENG D-J AUT
JI Proc. Inst. Mech. Eng. Part D-J. Automob. Eng.
PD NOV
PY 2008
VL 222
IS D11
BP 1939
EP 1954
DI 10.1243/09544070JAUTO811
PG 16
WC Engineering, Mechanical; Transportation Science & Technology
SC Engineering; Transportation
GA 389MG
UT WOS:000262096500001
ER
PT J
AU Hora, JL
Carey, S
Surace, J
Marengo, M
Lowrance, P
Glaccum, WJ
Lacy, M
Reach, WT
Hoffmann, WF
Barmby, P
Willner, SP
Fazio, GG
Megeath, ST
Allen, LE
Bhattacharya, B
Quijada, M
AF Hora, Joseph L.
Carey, Sean
Surace, Jason
Marengo, Massimo
Lowrance, Patrick
Glaccum, William J.
Lacy, Mark
Reach, William T.
Hoffmann, William F.
Barmby, Pauline
Willner, S. P.
Fazio, Giovanni G.
Megeath, S. Thomas
Allen, Lori E.
Bhattacharya, Bidushi
Quijada, Manuel
TI Photometry using the Infrared Array Camera on the Spitzer Space
Telescope
SO PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF THE PACIFIC
LA English
DT Article
ID CALIBRATION; CLOUD; IRAC
AB We present several corrections for point-source photometry to be applied to data from the Infrared Array Camera (IRAC) on the Spitzer Space Telescope. These corrections are necessary because of characteristics of the IRAC arrays and optics and the way the instrument is calibrated in flight. When these corrections are applied, it is possible to achieve a similar to 2% relative photometric accuracy for sources of adequate signal-to-noise ratio in an IRAC image.
C1 [Hora, Joseph L.; Marengo, Massimo; Willner, S. P.; Fazio, Giovanni G.; Allen, Lori E.] Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA.
[Carey, Sean; Surace, Jason; Lowrance, Patrick; Glaccum, William J.; Lacy, Mark; Reach, William T.] CALTECH, Spitzer Sci Ctr, Pasadena, CA 91125 USA.
[Hoffmann, William F.] Univ Arizona, Steward Observ, Tucson, AZ USA.
[Barmby, Pauline] Univ Western Ontario, Dept Phys & Astron, London, ON N6A 3K7, Canada.
[Megeath, S. Thomas] Univ Toledo, Ritter Observ, Toledo, OH 43606 USA.
[Bhattacharya, Bidushi] CALTECH, NASA Herschel Sci Ctr, Pasadena, CA 91125 USA.
[Quijada, Manuel] NASA, Goddard Space Flight Ctr, Opt Branch, Greenbelt, MD 20771 USA.
RP Hora, JL (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA.
EM jhora@cfa.harvard.edu
RI Barmby, Pauline/I-7194-2016;
OI Barmby, Pauline/0000-0003-2767-0090; Hora, Joseph/0000-0002-5599-4650;
Reach, William/0000-0001-8362-4094
FU Spitzer Space Telescope; NASA [1407]
FX This work is based on observations made with the Spitzer Space
Telescope, which is operated by the Jet Propulsion Laboratory,
California Institute of Technology, under NASA contract 1407. Support
for this work was provided by NASA through an award issued by
JPL/Caltech.
NR 17
TC 35
Z9 35
U1 0
U2 1
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0004-6280
J9 PUBL ASTRON SOC PAC
JI Publ. Astron. Soc. Pac.
PD NOV
PY 2008
VL 120
IS 873
BP 1233
EP 1243
DI 10.1086/593217
PG 11
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 371VN
UT WOS:000260860200008
ER
PT J
AU Thompson, DJ
AF Thompson, D. J.
TI Gamma ray astrophysics: the EGRET results
SO REPORTS ON PROGRESS IN PHYSICS
LA English
DT Review
ID POSITRON-ANNIHILATION RADIATION; EXPERIMENT TELESCOPE EGRET; ACTIVE
GALACTIC NUCLEI; PULSAR PSR J0218+4232; COS-B OBSERVATION; SOURCE 2CG
135+01; VERY-HIGH-ENERGY; SUPERNOVA-REMNANTS; SOURCE 3EG;
MULTIWAVELENGTH OBSERVATIONS
AB Cosmic gamma rays provide insight into some of the most dynamic processes in the Universe. At the dawn of a new generation of gamma-ray telescopes, this review summarizes results from the Energetic Gamma Ray Experiment Telescope (EGRET) on the Compton Gamma Ray Observatory, the principal predecessor mission studying high-energy photons in the 100 MeV energy range. EGRET viewed a gamma-ray sky dominated by prominent emission from the Milky Way, but featuring an array of other sources, including quasars, pulsars, gamma-ray bursts and many sources that remain unidentified. A central feature of the EGRET results was the high degree of variability seen in many gamma-ray sources, indicative of the powerful forces at work in objects visible to gamma-ray telescopes.
C1 NASA, Goddard Space Flight Ctr, Astrophys Sci Div, Greenbelt, MD 20771 USA.
RP Thompson, DJ (reprint author), NASA, Goddard Space Flight Ctr, Astrophys Sci Div, Greenbelt, MD 20771 USA.
EM David.J.Thompson@nasa.gov
RI Thompson, David/D-2939-2012
OI Thompson, David/0000-0001-5217-9135
NR 168
TC 45
Z9 46
U1 0
U2 0
PU IOP PUBLISHING LTD
PI BRISTOL
PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND
SN 0034-4885
J9 REP PROG PHYS
JI Rep. Prog. Phys.
PD NOV
PY 2008
VL 71
IS 11
AR 116901
DI 10.1088/0034-4885/71/11/116901
PG 23
WC Physics, Multidisciplinary
SC Physics
GA 370JM
UT WOS:000260758500002
ER
PT J
AU Sengupta, A
Kulleck, J
Hill, N
Ohlinger, W
AF Sengupta, Anita
Kulleck, James
Hill, Norm
Ohlinger, Wayne
TI Invited Article: Physical and chemical analyses of impregnated cathodes
operated in a plasma environment
SO REVIEW OF SCIENTIFIC INSTRUMENTS
LA English
DT Article
DE cathodes; discharges (electric); erosion; life testing
ID HOLLOW CATHODES
AB Destructive analyses of impregnated-cathode assemblies from an ion thruster life test were performed to characterize erosion and degradation after 30 472 h of operation. Post-test inspection of each cathode included examination of the emitter (insert), orifice plate, cathode tube, heater, anode assembly, insulator, and propellant isolator. The discharge-cathode assembly experienced significant erosion due to ion sputtering from the discharge plasma. The keeper electrode plate was removed and the heater and orifice plate were heavily eroded at the conclusion of the test. Had the test continued, these processes would likely have led to cathode failure. The discharge cathode insert experienced significant tungsten transport and temperature dependent barium oxide depletion within the matrix. Using barium depletion semiempirical relations developed by Palluel and Shroff, it is estimated that 25 000 h of operation remained in the discharge insert at the conclusion of the test. In contrast, the neutralizer insert exhibited significantly less tungsten transport and barium oxide depletion consistent with its lower current operation. The neutralizer was estimated to have 140 000 h of insert life remaining at the conclusion of the test. Neither insert had evidence of tungstate or oxide layer formation, previously known to have impeded cathode ignition and operation in similar long duration hollow-cathode tests. The neutralizer cathode was in excellent condition at the conclusion of the test with the exception of keeper tube erosion from direct plume-ion impingement, a previously underappreciated life-limiting mechanism. The most critical finding from the test was a power dependent deposition process within the neutralizer-cathode orifice. The process manifested at low-power operation and led to the production of energetic ions in the neutralizer plume, a potential life-limiting process for the neutralizer. Subsequent return of the engine and neutralizer operation to full-power removed the deposits and energetic ion production ceased.
C1 [Sengupta, Anita; Kulleck, James] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[Hill, Norm] Georgia Inst Technol, Sch Mat Sci & Engn, Atlanta, GA 30332 USA.
RP Sengupta, A (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
FU National Aeronautics and Space Administration
FX The authors would like to acknowledge Rich Schafer of the Georgia
Institute of Technology and Lois Lewis, Ron Ruiz, Al Owens, and John
Brophy of the Jet Propulsion Laboratory. The Jet Propulsion Laboratory,
California Institute of Technology, carried out the research described
in this paper, under a contract with the National Aeronautics and Space
Administration.
NR 29
TC 4
Z9 4
U1 3
U2 6
PU AMER INST PHYSICS
PI MELVILLE
PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1,
MELVILLE, NY 11747-4501 USA
SN 0034-6748
J9 REV SCI INSTRUM
JI Rev. Sci. Instrum.
PD NOV
PY 2008
VL 79
IS 11
AR 111301
DI 10.1063/1.3005784
PG 14
WC Instruments & Instrumentation; Physics, Applied
SC Instruments & Instrumentation; Physics
GA 376WB
UT WOS:000261212600001
PM 19045882
ER
PT J
AU Noorda, R
Noorda, J
Patterson, J
Schneider, JA
Dyess, M
Hastings, WC
Delay, TK
AF Noorda, R.
Noorda, J.
Patterson, J.
Schneider, J. A.
Dyess, M.
Hastings, W. C.
Delay, T. K.
TI Development of COPV's for High Pressure, In-Space, Cryogenic Fuel
Storage
SO SAMPE JOURNAL
LA English
DT Article
AB Polymeric composite overwrapped pressure vessels (COPV) provide an attractive material system to support developing commercial launch business and alternate fuel ventures. However to be able to design with these materials, the mechanical behavior of the materials must be understood with regards to processing, performance, damage tolerance, and environment. For the storage of cryogenic propellants, it is important to evaluate the materials performance and impact damage resistance at cryogenic temperatures in order to minimize weight and to ensure safety and reliability. To evaluate the ultimate performance, various polymeric COPV have been statically burst tested at cryogenic conditions before and after exposure to irradiation. Materials selected for these COP V were based on the measured mechanical properties of candidate resin systems and fibers that were also tested at cryogenic conditions before and after exposure to it-radiation. The correlation of COP V burst pressures with the constituent material properties has proven to be a valuable screening method for selection of suitable candidate materials with resistance to material degradation due to exposure to temperature and radiation.
C1 [Noorda, R.; Noorda, J.; Patterson, J.] HyPerComp Engn Inc, Brigham City, UT USA.
[Schneider, J. A.; Dyess, M.; Hastings, W. C.] Mississippi State Univ, Dept Mech Engn, Mississippi State, MS 39762 USA.
[Delay, T. K.] NASA, George C Marshall Space Flight Ctr, Nonmetall Mfg Proc, Huntsville, AL 35812 USA.
RP Noorda, R (reprint author), HyPerComp Engn Inc, Brigham City, UT USA.
EM judys@me.msstate.edu
FU NASA-STTR Phase I [NNM05AA61C (HEI/MSU), NNM05AA45C (HEI)]; NASA-SBIR
Phase II [NNM05AA45C (HEI/MSU), NNM06AA15C (HEI)]
FX This effort was performed under contracts: NASA-STTR Phase I Contract
#NNM05AA61C (HEI/MSU), NASA-SBIR Phase II Contract # NNM05AA45C
(HEI/MSU), NASA-SBIR Phase I Contract #NNM05AA45C (HEI) and NASA-SBIR
Phase II Contract #NNM06AA15C (HEI). The authors wish to thank Ron
Allred, President of Adherent Technologies, for assistance with the
fiber sizing studies.
NR 7
TC 0
Z9 0
U1 2
U2 8
PU SAMPE PUBLISHERS
PI COVINA
PA 1161 PARKVIEW DRIVE, COVINA, CA 91722 USA
SN 0091-1062
J9 SAMPE J
JI Sampe J.
PD NOV-DEC
PY 2008
VL 44
IS 6
BP 6
EP 14
PG 9
WC Engineering, Multidisciplinary; Materials Science, Multidisciplinary
SC Engineering; Materials Science
GA 367ZV
UT WOS:000260592000003
ER
PT J
AU Hu, ZW
De Carlo, F
AF Hu, Z. W.
De Carlo, F.
TI Noninvasive three-dimensional visualization of defects and crack
propagation in layered foam structures by phase-contrast microimaging
SO SCRIPTA MATERIALIA
LA English
DT Article
DE Layered structures; Interface defects; Foams; Stress-rupture; Imaging
ID X-RAYS; MICROTOMOGRAPHY; TOMOGRAPHY
AB Layered polymer foam structures used to insulate the fuel tank on the Space Shuttle were investigated by combining phase-contrast X-ray three-dimensional imaging and loading. It is shown that the interlayers between layers were distinctly different from the layers, resulting in incoherent interfaces where defects developed due to severe mismatch of cell structure between the mechanically weaker layers and stronger interlayers. These images reveal noninvasively that cracks nucleated readily at the interfaces and grew preferably along the direction of foam rise. (C) 2008 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
C1 [Hu, Z. W.] NASA, George C Marshall Space Flight Ctr, BAE Syst, Huntsville, AL 35812 USA.
[De Carlo, F.] Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA.
RP Hu, ZW (reprint author), NASA, George C Marshall Space Flight Ctr, BAE Syst, Huntsville, AL 35812 USA.
EM zhengwei.hu-l@nasa.gov
FU NASA/Marshall Space Flight Center; U.S. Department of Energy, Office of
Science, Office of Basic Energy Sciences [DE-AC02-06CH11357]
FX Z.W.H. thank Mr. B. Tiemen and Ms. P. Fernandez for help with data
processing and cryogenic testing, respectively. Mr. M. Suits, Mr. J.
Walker and Ms. B. Cook are thanked for their support and encouragement.
The work was supported by the Advanced Materials for Exploration Element
and the Biotechnology Science Program at NASA/Marshall Space Flight
Center. Use of the APS was supported by the U.S. Department of Energy,
Office of Science, Office of Basic Energy Sciences, under contract No.
DE-AC02-06CH11357.
NR 22
TC 2
Z9 2
U1 1
U2 5
PU PERGAMON-ELSEVIER SCIENCE LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
SN 1359-6462
J9 SCRIPTA MATER
JI Scr. Mater.
PD NOV
PY 2008
VL 59
IS 10
BP 1127
EP 1130
DI 10.1016/j.scriptamat.2008.07.043
PG 4
WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary;
Metallurgy & Metallurgical Engineering
SC Science & Technology - Other Topics; Materials Science; Metallurgy &
Metallurgical Engineering
GA 357ZL
UT WOS:000259885800026
ER
PT J
AU Juckett, DA
Wolff, CL
AF Juckett, David A.
Wolff, Charles L.
TI Evidence for Long-term Retrograde Motions of Sunspot Patterns and
Indications of Coupled g-mode Rotation Rates
SO SOLAR PHYSICS
LA English
DT Article
DE Sunspots; G-modes; Solar interior; Rotation; Solar cycle; Solar
activity; Spherical harmonics; Stackplots
ID DIFFERENTIAL ROTATION; ACTIVE LONGITUDES; SOLAR; OSCILLATIONS; SUN;
PERSISTENCE; SURFACE
AB Solar g-modes are global oscillations that would exist primarily in the radiative zone (RZ) and would be excited by either convective overshoot or nuclear burning in the core. Wolff and O'Donovan (Astrophys. J. 661, 568, 2007) proposed a non-linear coupling of g-modes into groups that share the same harmonic degree l. Each group (denoted set(l)) exhibits a unique retrograde rotation rate with respect to the RZ that depends mainly on l. The coupling yields a standing wave (nearly stationary in longitude) that has two angularly defined hot spots offset from the equator on opposite sides of the Sun that would deposit energy asymmetrically in the lower convective envelope (CE). It is anticipated that when two or more groups overlap in longitude, an increase in local heating would influence the distribution of sunspots. In this paper, we scanned a multitude of rotational reference frames for sunspot clustering to test for frames that are concordant with the rotation of these g-modes sets. To achieve this, spherical harmonic filtering of sunspot synoptic maps was used to extract patterns consistent with coalesced g-modes. The latitude band, with minimal differential rotation, was sampled from each filtered synoptic map and layered into a stackplot. This was progressively shifted, line-by-line, into different rotational reference frames. We have detected long-lived longitudinal alignments, spanning 90 years of solar cycles, which are consistent with the rotation rate of the deep solar interior as well as other rotational frames predicted by the coupled g-mode model. Their sidereal rotation rates of 370.0, 398.8, 412.7, 418.3, 421.0, 424.2 and 430.0 nHz correspond, respectively, to coupled g-modes for l = 2 through 7 and G, where G is a set with high l values or a group of such sets (unresolved) that rotate almost as fast as the RZ. While the clustering in these reference frames offers new approaches for studying the longitudinal behavior of solar activity, it tentatively leads to the more profound conclusion that a portion of the driving force for sunspot occurrence is linked to energy extracted from the solar core and deposited at the top of the RZ by solar g-modes.
C1 [Juckett, David A.] Michigan State Univ, Dept Chem, E Lansing, MI 48824 USA.
[Wolff, Charles L.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
[Juckett, David A.] Barros Res Inst, Holt, MI USA.
RP Juckett, DA (reprint author), Barros Res Inst, Holt, MI USA.
EM juckett@msu.edu; charles.l.wolff@nasa.gov
OI Wolff, Charles/0000-0001-8854-507X
NR 24
TC 3
Z9 3
U1 0
U2 1
PU SPRINGER
PI DORDRECHT
PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS
SN 0038-0938
J9 SOL PHYS
JI Sol. Phys.
PD NOV
PY 2008
VL 252
IS 2
BP 247
EP 266
DI 10.1007/s11207-008-9265-x
PG 20
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 367BD
UT WOS:000260526600003
ER
PT J
AU Scott, JT
Martens, PCH
Cirtain, JW
AF Scott, J. T.
Martens, P. C. H.
Cirtain, J. W.
TI Analysis of Two Coronal Loops with Combined TRACE and SOHO/CDS Data
SO SOLAR PHYSICS
LA English
DT Article
DE Sun: corona; Sun: EUV; Sun: coronal loops; Sun: spectra
ID TRANSITION-REGION; SOLAR; TEMPERATURE; EXPLORER
AB We use an innovative research technique to analyze combined images from the Coronal Diagnostic Spectrometer (CDS) on the Solar and Heliospheric Observatory (SOHO) and the Transition Region and Coronal Explorer (TRACE). We produce a high spatial and temporal resolution simulated CDS raster or "composite" map from TRACE data and use this composite map to jointly analyze data from both instruments. We show some of the advantages of using the "composite" map method for coronal loop studies. We investigate two postflare loop structures. We find cool material (250 000 K) concentrated at the tips or apex of the loops. This material is found to be above its scale height and therefore not in hydrostatic equilibrium. The exposure times of the composite map and TRACE images are used to give an estimate of another loop's cooling time. The contribution to the emission in the TRACE images for the spectral lines present in its narrow passband is estimated by using the CDS spectral data and CHIANTI to derive synthetic spectra. We obtain cospatial and cotemporal data collected by both instruments in SOHO Joint Observations Program (JOP) 146 and show how the combination of these data can be utilized to obtain more accurate measurements of coronal plasmas than if analyzed individually.
C1 [Scott, J. T.; Martens, P. C. H.; Cirtain, J. W.] Montana State Univ, Dept Phys, Bozeman, MT 59717 USA.
[Martens, P. C. H.; Cirtain, J. W.] Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA.
[Cirtain, J. W.] NASA, George C Marshall Space Flight Ctr, Solar Phys Grp, Natl Space Sci & Technol Ctr VP62, Huntsville, AL 35805 USA.
RP Scott, JT (reprint author), Montana State Univ, Dept Phys, Bozeman, MT 59717 USA.
EM scott@solar.physics.montana.edu
FU NASA [NAS5-38099]; Lockheed-Martin Solar and Astrophysics Laboratory;
NASA Graduate Students Research Program [NNG05GK64H]
FX The authors would like to thank the reviewer for constructive comments
that gave the paper more clarity. The authors thank the SOHO/CDS and
TRACE consortia for their data. TRACE mission operations and data
analysis at Montana State University are supported by NASA Grant
NAS5-38099, through a subcontract with Lockheed-Martin Solar and
Astrophysics Laboratory. J.S. is supported through NASA Graduate
Students Research Program Grant NNG05GK64H.
NR 23
TC 1
Z9 1
U1 0
U2 0
PU SPRINGER
PI DORDRECHT
PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS
SN 0038-0938
J9 SOL PHYS
JI Sol. Phys.
PD NOV
PY 2008
VL 252
IS 2
BP 293
EP 304
DI 10.1007/s11207-008-9259-8
PG 12
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 367BD
UT WOS:000260526600006
ER
PT J
AU Mierla, M
Davila, J
Thompson, W
Inhester, B
Srivastava, N
Kramar, M
Cyr, OCS
Stenborg, G
Howard, RA
AF Mierla, M.
Davila, J.
Thompson, W.
Inhester, B.
Srivastava, N.
Kramar, M.
Cyr, O. C. St.
Stenborg, G.
Howard, R. A.
TI A Quick Method for Estimating the Propagation Direction of Coronal Mass
Ejections Using STEREO-COR1 Images
SO SOLAR PHYSICS
LA English
DT Article
DE Corona: structures; Coronal mass ejections: initiation and propagation
ID CONE MODEL; SECCHI; LASCO
AB We describe here a method to obtain the position of a coronal moving feature in a three-dimensional coordinate system based on height-time measurements applied to STEREO data. By using the height-time diagrams from the two SECCHI-COR1 coronagraphs onboard STEREO, one can easily determine the direction of propagation of a coronal mass ejection (i.e., if the moving plasma is oriented toward or away from the Earth). This method may prove to be a useful tool for space weather forecasting by easily identifying the direction of propagation as well as the real speed of the coronal mass ejections.
C1 [Mierla, M.] Royal Observ Belgium, B-1180 Brussels, Belgium.
[Mierla, M.] Acad Romana, Astron Inst, Bucharest 040557, Romania.
[Davila, J.; Cyr, O. C. St.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
[Thompson, W.] Adnet Syst Inc, Rockville, MD 20852 USA.
[Inhester, B.; Srivastava, N.] Max Planck Inst Sonnensyst Forsch, D-37191 Katlenburg Lindau, Germany.
[Srivastava, N.] Udaipur Solar Observ, Udaipur 313001, India.
[Kramar, M.] Catholic Univ Amer, Washington, DC 20064 USA.
[Stenborg, G.] Interferometrics Inc, Herndon, VA 20171 USA.
[Howard, R. A.] USN, Res Lab, Washington, DC 20375 USA.
RP Mierla, M (reprint author), Royal Observ Belgium, Ringlaan 3, B-1180 Brussels, Belgium.
EM marilena@oma.be; josephmdavila@gmail.com; william.t.thompson@nasa.gov;
binhest@mps.mpg.de; nandita@prl.res.in; kramar@helio.gsfc.nasa.gov;
orville.c.stcyr@nasa.gov; stenborg@kreutz.nascom.nasa.gov;
russ.howard@nrl.navy.mil
RI Thompson, William/D-7376-2012
NR 21
TC 40
Z9 42
U1 0
U2 2
PU SPRINGER
PI DORDRECHT
PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS
SN 0038-0938
J9 SOL PHYS
JI Sol. Phys.
PD NOV
PY 2008
VL 252
IS 2
BP 385
EP 396
DI 10.1007/s11207-008-9267-8
PG 12
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 367BD
UT WOS:000260526600011
ER
PT J
AU Goering, J
Sah, S
Burghaus, U
Street, KW
AF Goering, J.
Sah, Shweta
Burghaus, U.
Street, K. W., Jr.
TI Adsorption of water on JSC-1A (simulated moon dust samples) - a surface
science study
SO SURFACE AND INTERFACE ANALYSIS
LA English
DT Article
DE AES; SEM; EDX; TDS; water; kinetics; simulated moon dust samples;
JSC-1a; aluminosilicate glass; silica wafer; materials gap
ID AMORPHOUS SOLID WATER; CARBON NANOTUBES; MOLECULAR-BEAM; FILMS; ICE;
HYDROGEN; SILICA; DESORPTION; ANISOTROPY; THIOPHENE
AB JSC-1a (a simulated lunar dust sample) supported on a silica wafer (SiO(2)/Si(111)) has been characterized by scanning electron microscopy (SEM), energy dispersive x-ray (EDX) spectroscopy, and Auger electron spectroscopy (AES). The adsorption kinetics of water has been studied primarily by thermal desorption spectroscopy(TDS) and in addition by collecting isothermal adsorption transients. Blind experiments on the silica support have been performed as well. JSC-1a consists mostly of aluminosilicate glass and other minerals containing Fe, Na, Ca, and Mg, as characterized in detail in prior studies, for example, at NASA. The particle sizes span the range from a few micrometers up to 100 gm. Al small exposures, H(2)O TDS is characterized by broad (100-450) K structures; at large exposures, distinct TDS peaks emerge, which are assigned to amorphous solid water (ASW) (145 K) and crystalline ice (CI) (1165 K). Water dissociates on JSC-1a at small exposures but not on the bare silica support. Coadsorption TDS data (alkane-water mixtures) indicate that rather porous condensed ice layers form at large exposures, with the mineral particles acting most likely as nucleation sites. At thermal impact energies, the initial adsorption probability amounts to 0.92 +/- 0.05. It is evident that the drop-and-dry technique, developed in studies about nanoparticles/tubes, can be extended to obtain samples for surface science studies based on powders consisting of particles with rather large diameters. Copyright (C) 2008 John Wiley & Sons, Ltd.
C1 [Goering, J.; Sah, Shweta; Burghaus, U.] N Dakota State Univ, Dept Chem & Mol Biol, Fargo, ND 58105 USA.
[Street, K. W., Jr.] NASA, John Glenn Res Ctr, Tribol & Surface Sci Branch, Cleveland, OH 44135 USA.
RP Burghaus, U (reprint author), N Dakota State Univ, Dept Chem & Mol Biol, Fargo, ND 58105 USA.
EM uwe.burghaus@ndsu.edu
FU ND NASA EPSCoR [NNXO7AK91A]; NASA Dust Mitigation Project
FX Discussions with Phil Abel and James Gaier (NASA Glenn), assistance by
Duane Dixon (NASA Glenn) in collecting the SEM data, and M. Komarneni
(NDSU), as well as financial support from ND NASA EPSCoR (Seed Grant
#NNXO7AK91A subaward #885), and from the NASA Dust Mitigation Project of
the Exploration Technology Development Program are acknowledged.
NR 36
TC 8
Z9 8
U1 0
U2 6
PU JOHN WILEY & SONS LTD
PI CHICHESTER
PA THE ATRIUM, SOUTHERN GATE, CHICHESTER PO19 8SQ, W SUSSEX, ENGLAND
SN 0142-2421
J9 SURF INTERFACE ANAL
JI Surf. Interface Anal.
PD NOV
PY 2008
VL 40
IS 11
BP 1423
EP 1429
DI 10.1002/sia.2918
PG 7
WC Chemistry, Physical
SC Chemistry
GA 375KQ
UT WOS:000261113100002
ER
PT J
AU Fishman, JM
Ellis, SR
Hasser, CJ
Stern, JD
AF Fishman, Jonathan M.
Ellis, Stephen R.
Hasser, Christopher J.
Stern, John D.
TI Effect of reduced stereoscopic camera separation on ring placement with
a surgical telerobot
SO SURGICAL ENDOSCOPY AND OTHER INTERVENTIONAL TECHNIQUES
LA English
DT Article
DE Stereoscopic display; Laparoscopic surgery; Intercamera distance; Human
factors
ID PERFORMANCE
AB Background A custom, stereoscopic video camera was built to study the impact of decreased camera separation on a stereoscopically viewed, visual-manual task resembling some aspects of surgery.
Materials and methods Twelve naive subjects and one of the experimenters were first trained in a ring placement task using the stereo-laparoscope and subsequently switched to the stereo-camera, which was used with differing camera separations ranging from 100% of the laparoscope's separation to a biocular view corresponding to no separation (2D).
Results The results suggest firstly, that stereopsis (i.e., use of 3D laparoscopes) improves surgical performance over conventional 2D laparoscopes, and secondly that camera separation may be reduced 20-35% without appreciably degrading user performance. Even a 50% reduction in separation resulted in stereoscopically supported performance far superior compared to the 2D condition.
Conclusions The results suggest that existing 3D laparoscopes which use 5-mm camera separation may well be significantly miniaturized without causing substantial performance degradation.
C1 [Fishman, Jonathan M.; Ellis, Stephen R.] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
[Fishman, Jonathan M.] Univ Oxford, John Radcliffe Hosp, Dept Surg, Oxford OX3 9DU, England.
[Hasser, Christopher J.; Stern, John D.] Intuit Surg, Sunnyvale, CA USA.
RP Fishman, JM (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
EM jfishman@doctors.org.uk
FU Code UL at NASA headquarters; Code THH at NASA Ames; Intuitive Surgical,
Inc
FX This research was partially funded by internal NASA support from Code UL
at NASA headquarters and Code THH at NASA Ames and by in-kind personnel
and development support from Intuitive Surgical, Inc. This paper is
based on, and extends, our preliminary report in a 2005 SPIE proceedings
[8].
NR 9
TC 4
Z9 4
U1 0
U2 2
PU SPRINGER
PI NEW YORK
PA 233 SPRING ST, NEW YORK, NY 10013 USA
SN 0930-2794
J9 SURG ENDOSC
JI Surg. Endosc.
PD NOV
PY 2008
VL 22
IS 11
BP 2396
EP 2400
DI 10.1007/s00464-008-0032-8
PG 5
WC Surgery
SC Surgery
GA 389JQ
UT WOS:000262089100011
PM 18618177
ER
PT J
AU Bol'shakov, AA
Cruden, BA
AF Bol'shakov, A. A.
Cruden, B. A.
TI Diagnostics of the inductively coupled plasma by diode laser absorption
spectroscopy
SO TECHNICAL PHYSICS
LA English
DT Article
DE 52; 70; Kz; 52; 65; -y
ID ATOMIC FLUORESCENCE SPECTROMETRY; SURFACE-EMITTING LASERS; GAS
TEMPERATURE; SEMICONDUCTOR-LASER; REFERENCE CELL; RATE CONSTANTS; ARGON;
DISCHARGE; PRESSURE; DENSITIES
AB A vertical-cavity surface-emitting diode laser is used as a tunable emission source to measure the radius-integrated gas temperature in an inductively coupled plasma reactor. Relevant data are obtained by profiling the Doppler-broadened absorption of metastable Ar atoms at 763.51 nm in argon and argon-nitrogen (3, 45, and 90% N-2 in Ar) plasmas in the pressure range 0.5-70.0 Pa and at an inductive power of 100 and 300 W. The results are compared with the rotational temperature of molecular nitrogen. The difference between the integrated rotational and Doppler temperatures is attributed to the nonuniform spatial distributions of the temperature and thermometric atomic and molecular species (Ar* and N*(2)). These distributions are computed in terms of the nonequilibrium hydrodynamic model of plasma. The objective of this work is to develop a contactless (nonintrusive) technique for measuring the temperature and concentration of different particles in the reactor with a microsensor.
C1 [Bol'shakov, A. A.] St Petersburg State Univ, Fock Inst Phys, St Petersburg 198504, Russia.
[Cruden, B. A.] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
RP Bol'shakov, AA (reprint author), St Petersburg State Univ, Fock Inst Phys, Ul Ulyanovskaya 1, St Petersburg 198504, Russia.
EM alexandb@mail.ru
RI Bol'shakov, Alexander/A-9258-2015
OI Bol'shakov, Alexander/0000-0002-6034-7079
NR 60
TC 2
Z9 2
U1 0
U2 3
PU MAIK NAUKA/INTERPERIODICA/SPRINGER
PI NEW YORK
PA 233 SPRING ST, NEW YORK, NY 10013-1578 USA
SN 1063-7842
EI 1090-6525
J9 TECH PHYS+
JI Tech. Phys.
PD NOV
PY 2008
VL 53
IS 11
BP 1423
EP 1432
DI 10.1134/S1063784208110054
PG 10
WC Physics, Applied
SC Physics
GA 371UN
UT WOS:000260857000005
ER
PT J
AU Harm, DL
Taylor, LC
Reschke, MF
Somers, JT
Bloomberg, JJ
AF Harm, Deborah L.
Taylor, Laura C.
Reschke, Millard F.
Somers, Jeffrey T.
Bloomberg, Jacob J.
TI Sensorimotor coordination aftereffects of exposure to a virtual
environment
SO VISUAL COMPUTER
LA English
DT Article; Proceedings Paper
CT 4th INTUITION International Conference and Workshop
CY OCT 04-05, 2007
CL Athens, GREECE
DE Virtual reality training; Eye-head-hand coordination; Gaze-holding;
Adaptation
ID ADAPTATION
AB Virtual reality environments (VRs) offer unique training opportunities, particularly for training astronauts and preadapting them to microgravity. The purpose of the current research was to compare disturbances in eye-head-hand (EHH) and eye-head (GAZE) sensorimotor coordination produced by repeated exposures to VR systems. In general, we observed significant increases in position errors in manual target acquisition for both horizontal and vertical targets. We also observed a significant decrement in the ability of subjects to maintain gaze on horizontal eccentric targets immediately after exposure to VR. These preliminary findings provide some direction for developing training schedules for VR users that facilitate adaptation and support the idea that VRs may serve as an analog for sensorimotor effects of spaceflight.
C1 [Harm, Deborah L.; Reschke, Millard F.; Bloomberg, Jacob J.] NASA Johnson Space Ctr, Houston, TX 77058 USA.
[Taylor, Laura C.; Somers, Jeffrey T.] Wyle Labs, Houston, TX 77058 USA.
RP Harm, DL (reprint author), NASA Johnson Space Ctr, 2101 NASA Pkwy, Houston, TX 77058 USA.
EM deborah.harm-1@nasa.gov
NR 18
TC 0
Z9 0
U1 1
U2 3
PU SPRINGER
PI NEW YORK
PA 233 SPRING ST, NEW YORK, NY 10013 USA
SN 0178-2789
J9 VISUAL COMPUT
JI Visual Comput.
PD NOV
PY 2008
VL 24
IS 11
BP 995
EP 999
DI 10.1007/s00371-008-0277-1
PG 5
WC Computer Science, Software Engineering
SC Computer Science
GA 359BQ
UT WOS:000259961600010
ER
PT J
AU Strack, JE
Pielke, RA
Steyaert, LT
Knox, RG
AF Strack, John E.
Pielke, Roger A., Sr.
Steyaert, Louis T.
Knox, Robert G.
TI Sensitivity of June near-surface temperatures and precipitation in the
eastern United States to historical land cover changes since European
settlement
SO WATER RESOURCES RESEARCH
LA English
DT Article
ID CLIMATE; MODELS; IMPACT; PARAMETERIZATION; ATMOSPHERE; FUTURE
AB Land cover changes alter the near surface weather and climate. Changes in land surface properties such as albedo, roughness length, stomatal resistance, and leaf area index alter the surface energy balance, leading to differences in near surface temperatures. This study utilized a newly developed land cover data set for the eastern United States to examine the influence of historical land cover change on June temperatures and precipitation. The new data set contains representations of the land cover and associated biophysical parameters for 1650, 1850, 1920, and 1992, capturing the clearing of the forest and the expansion of agriculture over the eastern United States from 1650 to the early twentieth century and the subsequent forest regrowth. The data set also includes the inferred distribution of potentially water-saturated soils at each time slice for use in the sensitivity tests. The Regional Atmospheric Modeling System, equipped with the Land Ecosystem-Atmosphere Feedback (LEAF-2) land surface parameterization, was used to simulate the weather of June 1996 using the 1992, 1920, 1850, and 1650 land cover representations. The results suggest that changes in surface roughness and stomatal resistance have caused present-day maximum and minimum temperatures in the eastern United States to warm by about 0.3 degrees C and 0.4 degrees C, respectively, when compared to values in 1650. In contrast, the maximum temperatures have remained about the same, while the minimums have cooled by about 0.1 degrees C when compared to 1920. Little change in precipitation was found.
C1 [Strack, John E.] Univ Maryland, ESSIC, College Pk, MD 20740 USA.
[Knox, Robert G.] NASA, Goddard Space Flight Ctr, Hydrospher & Biospher Sci Lab, Greenbelt, MD 20771 USA.
[Pielke, Roger A., Sr.] Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA.
[Steyaert, Louis T.] US Geol Survey, Greenbelt, MD USA.
RP Strack, JE (reprint author), Univ Maryland, ESSIC, Univ Maryland Res Pk,M Sq,5825 Univ Res Court,Sui, College Pk, MD 20740 USA.
EM jstrack@umd.edu
RI Knox, Robert/E-9657-2011; Pielke, Roger/A-5015-2009
FU USGS [06CRAG0023]; NASA [NNG04GL61G, NNX06AG74G]
FX The CPC U. S. Unified Precipitation data was provided by the
NOAA/OAR/ESRL PSD, Boulder, Colorado, USA, from their Web site at
http://www.cdc.noaa.gov/. The USSOD data were provided by the Data
Support Section of the Computational and Information Systems Laboratory
at the National Center for Atmospheric Research. NCAR is supported by
grants from the National Science Foundation. We would also like to
acknowledge our appreciation of the comments and suggestions of three
anonymous reviewers. Finally, this study was funded by USGS grant
06CRAG0023, NASA grant NNG04GL61G, and NASA grant NNX06AG74G.
NR 37
TC 13
Z9 13
U1 1
U2 5
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0043-1397
EI 1944-7973
J9 WATER RESOUR RES
JI Water Resour. Res.
PD NOV 1
PY 2008
VL 44
IS 11
AR W11401
DI 10.1029/2007WR006546
PG 13
WC Environmental Sciences; Limnology; Water Resources
SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water
Resources
GA 368EV
UT WOS:000260605000001
ER
PT J
AU Vasquez, RP
AF Vasquez, R. P.
TI Composition determination for complex and transmitting samples in x-ray
quantitative analysis
SO X-RAY SPECTROMETRY
LA English
DT Article
ID PHOTOIONIZATION CROSS-SECTIONS; EMISSION-TRANSMISSION METHOD;
INTENSITIES; INSTRUMENT; SEARCH; XRF
AB In this work, quantitative analysis of x-ray fluorescence measurements of transmitting samples with complex chemical composition is considered. A method is presented for analytical solution of sample composition including matrix effects, independent of sample thickness and requiring no standards. The method uses fundamental parameters and measured fluorescence signal intensities, and is applicable to transmission geometry measurements for which standard analyses are not applicable. Limitations of the analysis presented here are discussed. Copyright (C) 2008 John Wiley & Sons, Ltd.
C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Vasquez, RP (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM Richard.P.Vasquez@ipl.nasa.gov
FU National Aeronautics and Space Administration
FX This research was carried out at the jet Propulsion Laboratory,
California Institute of Technology, under a contract with the National
Aeronautics and Space Administration.
NR 14
TC 2
Z9 2
U1 2
U2 3
PU JOHN WILEY & SONS LTD
PI CHICHESTER
PA THE ATRIUM, SOUTHERN GATE, CHICHESTER PO19 8SQ, W SUSSEX, ENGLAND
SN 0049-8246
J9 X-RAY SPECTROM
JI X-Ray Spectrom.
PD NOV-DEC
PY 2008
VL 37
IS 6
BP 599
EP 602
DI 10.1002/xrs.1099
PG 4
WC Spectroscopy
SC Spectroscopy
GA 375LX
UT WOS:000261116500005
ER
PT J
AU Hecht, MH
Marshall, J
Pike, WT
Staufer, U
Blaney, D
Braendlin, D
Gautsch, S
Goetz, W
Hidber, HR
Keller, HU
Markiewicz, WJ
Mazer, A
Meloy, TP
Morookian, JM
Mogensen, C
Parrat, D
Smith, P
Sykulska, H
Tanner, RJ
Reynolds, RO
Tonin, A
Vijendran, S
Weilert, M
Woida, PM
AF Hecht, M. H.
Marshall, J.
Pike, W. T.
Staufer, U.
Blaney, D.
Braendlin, D.
Gautsch, S.
Goetz, W.
Hidber, H. -R.
Keller, H. U.
Markiewicz, W. J.
Mazer, A.
Meloy, T. P.
Morookian, J. M.
Mogensen, C.
Parrat, D.
Smith, P.
Sykulska, H.
Tanner, R. J.
Reynolds, R. O.
Tonin, A.
Vijendran, S.
Weilert, M.
Woida, P. M.
TI Microscopy capabilities of the Microscopy, Electrochemistry, and
Conductivity Analyzer
SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS
LA English
DT Article
ID ATOMIC-FORCE MICROSCOPE
AB The Phoenix microscopy station, designed for the study of Martian dust and soil, consists of a sample delivery system, an optical microscope, and an atomic force microscope. The combination of microscopies facilitates the study of features from the millimeter to nanometer scale. Light-emitting diode illumination allows for full color optical imaging of the samples as well as imaging of ultraviolet-induced visible fluorescence. The atomic force microscope uses an array of silicon tips and can operate in both static and dynamic mode.
C1 [Hecht, M. H.; Blaney, D.; Mazer, A.; Morookian, J. M.; Mogensen, C.; Weilert, M.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[Marshall, J.] SETI Inst, Mountain View, CA 94043 USA.
[Pike, W. T.; Vijendran, S.] Univ London Imperial Coll Sci Technol & Med, Dept Elect & Elect Engn, London SW7 2DD, England.
[Staufer, U.; Gautsch, S.; Parrat, D.] Univ Neuchatel, Inst Microtechnol, CH-2000 Neuchatel, Switzerland.
[Braendlin, D.] Nanosurf AG, CH-4410 Liestal, Switzerland.
[Goetz, W.; Keller, H. U.; Markiewicz, W. J.] Max Planck Inst Solar Syst Res, D-37191 Katlenburg Lindau, Germany.
[Hidber, H. -R.; Tonin, A.] Univ Basel, Dept Phys, CH-4003 Basel, Switzerland.
[Meloy, T. P.] W Virginia Univ, Coll Engn & Mineral Resources, Morgantown, WV 26501 USA.
[Smith, P.; Tanner, R. J.; Reynolds, R. O.; Woida, P. M.] Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA.
RP Hecht, MH (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM michael.h.hecht@jpl.nasa.gov
RI Gautsch, Sebastian/G-2561-2015; Staufer, Urs/J-6866-2016
OI Staufer, Urs/0000-0002-3519-6467
NR 14
TC 25
Z9 25
U1 2
U2 9
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0148-0227
J9 J GEOPHYS RES-PLANET
JI J. Geophys. Res.-Planets
PD OCT 31
PY 2008
VL 113
AR E00A22
DI 10.1029/2008JE003077
PG 28
WC Geochemistry & Geophysics
SC Geochemistry & Geophysics
GA 368DU
UT WOS:000260602300001
ER
PT J
AU Borsa, AA
Bills, BG
Minster, JB
AF Borsa, Adrian A.
Bills, Bruce G.
Minster, Jean-Bernard
TI Modeling the topography of the salar de Uyuni, Bolivia, as an
equipotential surface of Earth's gravity field
SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
LA English
DT Article
ID OVERLAND-FLOW; GEOID DETERMINATION; CENTRAL ANDES; REDUCTION;
EVAPORATION; EVAPORITES; SPHERE; LAKE; GPS
AB The salar de Uyuni is a massive dry salt lake that lies at the lowest point of an internal drainage basin in the Bolivain Altiplano. A kinematic GPS survey of the salar in September 2002 found a topographic range of only 80 cm over a 54 x 45 km area and subtle surface features that appeared to correlate with mapped gravity. In order to confirm the correlation between topography and gravity/geopotential, we use local gravity measurements and the EGM96 global geopotential model to construct a centimeter-level equipotential surface corresponding to the elevation of the salar. Our comparison of GPS survey elevations with equipotential surface estimate shows that 63% of the variance of the GPS elevations can be explained by equipotential surface undulations (and long-wavelength error) in the EGM96 model alone, with an additional 30% explained by the shorter-wavelength equipotential surface derived from local gravity. In order to establish a physical connection between topography and the geopotential, we also develop and test a simple surface process model that redistributes salt via the dissolution, transport, and redeposition of salt by precipitated water. Forcing within the model pushes the system to evolve toward constant water depth, with the salt surface approximating the shape of the local equipotential surface. Since the model removes almost all topographic relief with respect to the equipotential surface within a matter of decades, it appears that observed (similar to 5 cm amplitude, similar to 5 km wavelength) residual topography is actively maintained by a process independent of gravity-driven fluid flow.
C1 [Borsa, Adrian A.; Minster, Jean-Bernard] Univ Calif San Diego, Scripps Inst Oceanog, Inst Geophys & Planetary Phys, La Jolla, CA 92037 USA.
[Bills, Bruce G.] NASA, Goddard Space Flight Ctr, Planetary Geodynam Lab, Greenbelt, MD 20771 USA.
RP Borsa, AA (reprint author), Univ Calif San Diego, Scripps Inst Oceanog, Inst Geophys & Planetary Phys, La Jolla, CA 92037 USA.
EM borsa@unavco.org
OI Minster, Jean Bernard/0000-0003-1268-5177
FU NASA's ICESat Mission; NASA [NAS5-99006]
FX We thank NASA's ICESat Mission for its support of this work. This
research was funded through NASA contract NAS5-99006 to ICESat Team
Member Jean-Bernard Minster. We also wish to thank reviewers Joseph
Awange and Juergen Kusche for their insight and excellent feedback.
NR 47
TC 1
Z9 1
U1 0
U2 12
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 2169-9313
EI 2169-9356
J9 J GEOPHYS RES-SOL EA
JI J. Geophys. Res.-Solid Earth
PD OCT 31
PY 2008
VL 113
IS B10
AR B10408
DI 10.1029/2007JB005445
PG 21
WC Geochemistry & Geophysics
SC Geochemistry & Geophysics
GA 368EF
UT WOS:000260603400003
ER
PT J
AU Dubinin, E
Modolo, R
Fraenz, M
Woch, J
Chanteur, G
Duru, F
Akalin, F
Gurnett, D
Lundin, R
Barabash, S
Winningham, JD
Frahm, R
Plaut, JJ
Picardi, G
AF Dubinin, E.
Modolo, R.
Fraenz, M.
Woch, J.
Chanteur, G.
Duru, F.
Akalin, F.
Gurnett, D.
Lundin, R.
Barabash, S.
Winningham, J. D.
Frahm, R.
Plaut, J. J.
Picardi, G.
TI Plasma environment of Mars as observed by simultaneous MEX-ASPERA-3 and
MEX-MARSIS observations
SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
LA English
DT Article
ID PHOTOELECTRON ENERGY PEAKS; AMPTE ARTIFICIAL COMET; SOLAR-WIND
INTERACTION; PILE-UP BOUNDARY; MAGNETIC-FIELD; ASPERA-3 OBSERVATIONS;
VENUS; IONOSPHERE; NIGHTSIDE; MISSION
AB Simultaneous in situ measurements carried out by the Analyzer of Space Plasma and Energetic Atoms (ASPERA-3) and Mars Advanced Radar for Subsurface and Ionospheric Sounding (MARSIS) instruments on board the Mars Express (MEX) spacecraft for the first time provide us with the local parameters of the Martian magnetosphere and ionosphere. On the dayside, plasma of ionospheric and exospheric origin expands to large altitudes and gets in touch with the solar wind plasma. Formation of the magnetic field barrier which terminates the solar wind flow is governed by solar wind. The magnetic field rises up to the value which is just sufficient to balance the solar wind pressure while the position of the magnetospheric boundary varies insignificantly. Although, within the magnetic barrier, solar wind plasma is depleted, the total electron density increases owing to the enhanced contribution of planetary plasma. In some cases, a load caused by a planetary plasma becomes so strong that a pileup of the magnetic field occurs in a manner which forms a discontinuity (the magnetic pileup boundary). Generally, the structure of the magnetospheric boundary on the dayside varies considerably, and this variability is probably controlled by the magnetic field orientation. Inside the magnetospheric boundary, the electron density continues to increase and forms the photoelectron boundary which sometimes almost coincides with the magnetospheric boundary. The magnetic field strength also increases in this region, implying that the planetary plasma driven into the bulk motion transports the magnetic field inward. A cold and denser ionospheric plasma at lower altitudes reveals a tailward cometary-like expansion. large-amplitude osicllations in the number density of the ionospheric plasma are another typical feature. Crossings of plasma sheet at low altitudes in the terminator region are characterized by depletions in the density of the ionospheric component. In some cases, density depletions correlate with large vertical components of the crustal magnetic field. Such anticorrelation in the variations of the densities of the cold ionospheric and hot magenetosheath/plasma sheet plasmas is also rather typical for localized aurora-type events on the nightside.
C1 [Dubinin, E.; Fraenz, M.; Woch, J.] Max Planck Inst Solar Syst Res, D-37191 Katlenburg Lindau, Germany.
[Modolo, R.; Duru, F.; Akalin, F.; Gurnett, D.] Univ Iowa, Dept Phys & Astron, Iowa City, IA 52242 USA.
[Lundin, R.; Barabash, S.] Swedish Inst Space Phys, SE-98128 Kiruna, Sweden.
[Chanteur, G.] IPSL, Ctr Etud Environnements Terr & Planetaires, F-37191 Velizy Villacoublay, France.
[Winningham, J. D.; Frahm, R.] SW Res Inst, San Antonio, TX 78228 USA.
[Picardi, G.] Univ Roma La Sapienza, Dept Infocom, I-00184 Rome, Italy.
[Plaut, J. J.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Dubinin, E (reprint author), Max Planck Inst Solar Syst Res, Max Planck Str 2, D-37191 Katlenburg Lindau, Germany.
EM dubinin@mps.mpg.de; ronan-modolo@uiowa.edu; rickard@irf.se; stas@irf.se
FU DFG [WO 910/1-1]; DLR [50QM99035]; FKZ [50 QM 0801]; University of Iowa
[1224107]; Jet Propulsion Laboratory; Southwest Research Institute;
National Aeronautics and Space Administration [NASW-00003]
FX The authors (E. D., M. F.) wish to acknowledge support from DFG for
supporting this work by grant WO 910/1-1 and DLR by grants 50QM99035 and
FKZ 50 QM 0801. This research at the University of Iowa was funded by
contract 1224107 with the Jet Propulsion Laboratory and at Southwest
Research Institute by the National Aeronautics and Space Administration
contract NASW-00003.; Wolfgang Baumjohann thanks Janet Luhmann and Peter
Israelevich for their assistance in evaluating this paper.
NR 46
TC 27
Z9 27
U1 2
U2 5
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 2169-9380
EI 2169-9402
J9 J GEOPHYS RES-SPACE
JI J. Geophys. Res-Space Phys.
PD OCT 31
PY 2008
VL 113
IS A10
AR A10217
DI 10.1029/2008JA013355
PG 16
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 368EK
UT WOS:000260603900003
ER
PT J
AU Owens, MJ
Crooker, NU
Schwadron, NA
Horbury, TS
Yashiro, S
Xie, H
St Cyr, OC
Gopalswamy, N
AF Owens, M. J.
Crooker, N. U.
Schwadron, N. A.
Horbury, T. S.
Yashiro, S.
Xie, H.
St Cyr, O. C.
Gopalswamy, N.
TI Conservation of open solar magnetic flux and the floor in the
heliospheric magnetic field
SO GEOPHYSICAL RESEARCH LETTERS
LA English
DT Article
ID CORONAL MASS EJECTIONS; DISCONNECTION
AB The near-Earth heliospheric magnetic field intensity, \B\, exhibits a strong solar sycle variation, but returens to the same "floor" value each solar minimum. The current minimum, however, has seen \B\ drop below previous minima, bringing in to question the existence of a floor, or at the very least requiring a re-assessment of its value. In this study we assume heliospheric flux consists of a constant open flux component and a time-varying contribution from CMEs. In this scenario, the true floor is \B\ withh zero CME contribution. Using observed CME rates over the solar cycle, we estimate the "no-CME" \B\ floor at similar to 4.o+/-0.3 nT, lower than previous floor estimates and below \B\ observed this solar minimum. We speculate that the drop in \B\ observed this minimum may be due to a persistently lower CME rate than the previous minimum, though there are large uncertainties in the supporting observational data. Citation: Owens, M.J., N.U. Crooker, N.A.Schwadron, T.S. Horbury, S. Yashiro, H. Xie, O.C. St. Cyr, and N. Gopalswamy (2008), conservation of open solar magnetic flux and the floor in the heliospheric magnetic field, Geophys. Res. Lett., 35, L20108, doi: 10.1029/2008GL035813.
C1 [Owens, M. J.; Horbury, T. S.] Univ London Imperial Coll Sci Technol & Med, Blackett Lab, London SW7 2AZ, England.
[Crooker, N. U.; Schwadron, N. A.] Boston Univ, Ctr Space Phys, Boston, MA 02215 USA.
[St Cyr, O. C.; Gopalswamy, N.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
[Yashiro, S.; Xie, H.] Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA.
RP Owens, MJ (reprint author), Univ London Imperial Coll Sci Technol & Med, Blackett Lab, London SW7 2AZ, England.
EM m.ownes@imperial.ac.uk
RI Owens, Mathew/B-3006-2010; Gopalswamy, Nat/D-3659-2012
OI Owens, Mathew/0000-0003-2061-2453;
FU STFC (UK); NSF [ATM-0553397, ATM-012950]
FX This reaserch was funded by the STFC (UK). NC was supported by NSF grant
ATM-0553397. Work at BU wasalso supported by CISM which is funded by the
National Science Foundation STC program under Agreement ATM-012950.
NR 24
TC 44
Z9 44
U1 0
U2 1
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0094-8276
J9 GEOPHYS RES LETT
JI Geophys. Res. Lett.
PD OCT 30
PY 2008
VL 35
IS 20
AR L20108
DI 10.1029/2008GL035813
PG 5
WC Geosciences, Multidisciplinary
SC Geology
GA 368BW
UT WOS:000260597300005
ER
PT J
AU Yang, Q
Fu, Q
Austin, J
Gettelman, A
Li, F
Vomel, H
AF Yang, Qiong
Fu, Qiang
Austin, John
Gettelman, Andrew
Li, Feng
Voemel, Holger
TI Observationally derived and general circulation model simulated tropical
stratospheric upward mass fluxes
SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
LA English
DT Article
ID BREWER-DOBSON CIRCULATION; RADIATIVE PROPERTIES; CIRRUS CLOUDS; ACCURATE
PARAMETERIZATION; RESIDUAL CIRCULATION; CHANGING CLIMATE; DOWNWARD
CONTROL; ANNUAL CYCLE; WATER-VAPOR; OZONE
AB We quantify the vertical velocity and upward mass flux in the tropical lower stratosphere on the basis of accurate radiative heating rate calculations using 8-year Southern Hemisphere Additional Ozonesondes balloon-borne measurements of temperature and ozone and cryogenic frost-point hygrometer measured water vapor in the tropics (15 degrees S-10 degrees N). The impact of tropospheric clouds on the stratospheric heating rates is considered using cloud distributions from the International Satellite Cloud Climatology Project. We find a nearly constant annual mean upward mass flux in the tropical lower stratosphere above the top of the tropical tropopause layer (i.e., similar to 70 hPa), which is 1.13 +/- 0.40 kgm (-2)d(-1) for the 40- to 30-hPa layer, and 0.89 +/- 0.48 kgm (-2)d(-1) for the 70- to 50-hPa layer. A strong seasonal cycle exists in the upward mass flux and it is found that the mass flux below similar to 70 hPa is decoupled from that above in the Northern Hemisphere summer. Simulations of the tropical lower stratosphere from two stratospheric General Circulation Models (GCMs) are compared with observations. The annual mean upward mass fluxes from both GCMs for the 40- to 30-hPa layer agree well with observations, while the simulated mass fluxes for the 70- to 50-hPa layer are twice as large. Both GCMs also simulate seasonal variation of the mass flux reasonably well but are incapable of simulating the observed interannual variability of the upward mass flux, which is closely correlated with the quasi-biennial oscillations.
C1 [Yang, Qiong; Fu, Qiang] Univ Washington, Dept Atmospher Sci, Seattle, WA 98195 USA.
[Austin, John] Geophys Fluid Dynam Lab, Princeton, NJ 08542 USA.
[Gettelman, Andrew] Natl Ctr Atmospher Res, Boulder, CO 80305 USA.
[Li, Feng] Univ Maryland, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21250 USA.
[Voemel, Holger] Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA.
RP Yang, Q (reprint author), Univ Washington, Dept Atmospher Sci, Seattle, WA 98195 USA.
EM qyang@atmos.washington.edu
RI Li, Feng/H-2241-2012
FU NASA [NNX08AF66G]
FX We thank A.M. Thompson for useful discussions on the SHADOZ data. We
thank Fumio Hasebe, Masato Shiotani, and Masatomo Fujiwara for their
support of SOWER measurements. The ISCCP data are provided by the NASA
Langley Research Center Atmospheric Sciences Data Center. Q.Y. thanks G.
Anderson for the help on the MODTRAN4 software. This work is supported
by the NASA grant NNX08AF66G.
NR 61
TC 28
Z9 29
U1 0
U2 17
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 2169-897X
EI 2169-8996
J9 J GEOPHYS RES-ATMOS
JI J. Geophys. Res.-Atmos.
PD OCT 30
PY 2008
VL 113
IS D20
AR D00B07
DI 10.1029/2008JD009945
PG 12
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 368CD
UT WOS:000260598000007
ER
PT J
AU Koval, A
Szabo, A
AF Koval, A.
Szabo, A.
TI Modified "Rankine-Hugoniot" shock fitting technique: Simultaneous
solution for shock normal and speed
SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
LA English
DT Article
ID WIND; SPACECRAFT
AB We introduce a modification of the nonlinear least squares fitting technique of Vinas and Scudder and Szabo (VSSz) with simultaneous determination of the shock normal direction (theta and phi) and propagation speed O(V(S)). Similar to the 2D case of the VSSz technique, the uniqueness of the solution can still be graphically demonstrated in the 2D space of the unknown variables. The modified technique is validated through the analysis of synthetic shocks and is also applied to an interplanetary shock observed by Wind. Our technique provides self-consistent 3D confidence regions for the parameters while the VSSz technique assumes the independence of the V(S) confidence interval from theta and phi. The 3D confidence region is highly dependent on V(S) resulting in theta and phi joint confidence regions that are generally significantly larger and oriented differently than those obtained by the VSSz technique. This also leads to significantly larger confidence intervals for the individual parameters determined by our modified technique. While the best fit values provided by the two techniques are usually close to each other, we also demonstrate the advantage of the V(S) best fit value determination with our technique in the case when a small density jump is combined with significant density fluctuations. The agreement between the best fit solutions of the techniques can also be used as a test for the correctness of the chosen upstream and downstream intervals.
C1 [Koval, A.; Szabo, A.] NASA, Goddard Space Flight Ctr, Heliospher Phys Lab, Greenbelt, MD 20771 USA.
RP Koval, A (reprint author), NASA, Goddard Space Flight Ctr, Heliospher Phys Lab, Mail Code 672, Greenbelt, MD 20771 USA.
EM andriy.koval@nasa.gov; adam.szabo@nasa.gov
NR 11
TC 10
Z9 10
U1 0
U2 1
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0148-0227
J9 J GEOPHYS RES-SPACE
JI J. Geophys. Res-Space Phys.
PD OCT 30
PY 2008
VL 113
IS A10
AR A10110
DI 10.1029/2008JA013337
PG 9
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 368EJ
UT WOS:000260603800004
ER
PT J
AU Gutsev, GL
O'Neal, RH
Saha, BC
Mochena, MD
Johnson, E
Bauschlicher, CW
AF Gutsev, G. L.
O'Neal, R. H., Jr.
Saha, B. C.
Mochena, M. D.
Johnson, E.
Bauschlicher, C. W., Jr.
TI Optical Properties of (GaAs)(n) Clusters (n=2-16)
SO JOURNAL OF PHYSICAL CHEMISTRY A
LA English
DT Article
ID ELECTRONIC POPULATION ANALYSIS; MOLECULAR WAVE FUNCTIONS; SMALL GAAS
CLUSTERS; GALLIUM-ARSENIDE CLUSTERS; SEMICONDUCTOR CLUSTERS;
CORRELATION-ENERGY; STABLE STRUCTURES; BORON NITRIDES; HARTREE-FOCK;
DENSITY
AB The electronic and geometrical structures of the lowest triplet states of (GaAs), clusters (n = 2-16) are studied using density functional theory with generalized gradient approximation (DFT-GGA). It is found that the triplet-state geometries are different from the corresponding singlet-state geometries; for n = 2-8, 10, and 11, the triplets and singlets have different topologies, while the (GaAs)g, (GaAs) 12, (GaAs) 15, and (GaAs) 16 triplets possess a reduced symmetry, due to Jahn-Teller distortions. Except for GaAs, the singlet states are the ground states. Excitation energies and oscillator strengths are computed for excitations from the ground state to ten singlet states of all (GaAs),, clusters using time-dependent density functional theory. The adiabatic singlet-triplet gap is compared to the vertical gap, and the difference in the eigenvalues of the highest-occupied and lowest-unoccupied molecular orbitals (the HOMO-LUMO gap). While these three values show large oscillations for small n, they approach each other as the cluster size grows. Thus, the HOMO-LUMO gap computed using the DFT-GGA approach presents a rather reliable estimate of the adiabatic singlet-triplet gap.
C1 [Gutsev, G. L.; O'Neal, R. H., Jr.; Saha, B. C.; Mochena, M. D.] Florida A&M Univ, Dept Phys, Tallahassee, FL 32307 USA.
[Johnson, E.] Florida A&M Univ, Inst Environm Sci, Tallahassee, FL 32307 USA.
[Bauschlicher, C. W., Jr.] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
RP Gutsev, GL (reprint author), Florida A&M Univ, Dept Phys, Tallahassee, FL 32307 USA.
EM gennady.gutsev@famu.edu
FU U.S. Air Force AFRL [FA865005-D-1912]; National Science Foundation;
CREST program [0630370]; National Oceanic and Atmospheric Administration
(NOAA); United States Department of Commerce to the Environmental
Sciences Institute at Florida A M University [NA05OAR4811018]
FX This research was partly supported by the ML Program of U.S. Air Force
AFRL Contract No. FA865005-D-1912, by the National Science Foundation,
CREST program (Grant 0630370), and by funding from the National Oceanic
and Atmospheric Administration (NOAA) of the United States Department of
Commerce to the Environmental Sciences Institute at Florida A & M
University (NOAA Award No. NA05OAR4811018). We are very thankful to Drs.
Kirk Peterson and George Maroulis for instructive discussions.
NR 70
TC 26
Z9 27
U1 0
U2 12
PU AMER CHEMICAL SOC
PI WASHINGTON
PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA
SN 1089-5639
J9 J PHYS CHEM A
JI J. Phys. Chem. A
PD OCT 30
PY 2008
VL 112
IS 43
BP 10728
EP 10735
DI 10.1021/jp803888k
PG 8
WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical
SC Chemistry; Physics
GA 364TG
UT WOS:000260357600006
PM 18834095
ER
PT J
AU Ming, DW
Morris, RV
Woida, R
Sutter, B
Lauer, HV
Shinohara, C
Golden, DC
Boynton, WV
Arvidson, RE
Stewart, RL
Tamppari, LK
Gross, M
Smith, P
AF Ming, D. W.
Morris, R. V.
Woida, R.
Sutter, B.
Lauer, H. V.
Shinohara, C.
Golden, D. C.
Boynton, W. V.
Arvidson, R. E.
Stewart, R. L.
Tamppari, L. K.
Gross, M.
Smith, P.
TI Mars 2007 Phoenix Scout mission Organic Free Blank: Method to
distinguish Mars organics from terrestrial organics
SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS
LA English
DT Article
AB The Organic Free Blank (OFB) for the Mars 2007 Phoenix Scout mission provides an organic carbon null sample to compare against possible Martian organic signatures obtained by the Thermal and Evolved Gas Analyzer (TEGA). Major OFB requirements are an organic carbon content of <= 10 ng C g(-1) of sample, a nonporous structure, and strength and integrity that permits machining by the Robotic Arm (RA) Icy Soil Acquisition Device (ISAD). A specially fabricated form of commercial Macor(TM) (a machinable glass ceramic), made with nitrate salts replacing carbonate salts, was selected as the OFB material. The OFB has a total inorganic carbon content of approximately 1.6 mu g C g(-1) after fabrication, cleaning, and heat treatment in oxygen gas at 550 degrees C. The detection limit for organic carbon is similar to 100 ng C g(-1) of sample, or about a factor of 10 higher than the design goal. One scenario for OFB use on Mars is subsequent to the first TEGA detection of organic carbon. The OFB sample, acquired by the RA ISAD and delivered to TEGA, would come in contact with all surfaces in the sample transfer chain, collecting residual terrestrial contamination that accompanied the spacecraft to Mars. A second sample of the putative Martian organic-bearing material would then be obtained and analyzed by TEGA. Different organic contents and/or different mass spectrometer fragmentation patterns between the OFB material and the two Martian samples would indicate that the detected organic carbon is indigenous to Mars.
C1 [Ming, D. W.; Morris, R. V.] NASA, ARES, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA.
[Arvidson, R. E.] Washington Univ, Dept Earth & Planetary Sci, St Louis, MO 63130 USA.
[Woida, R.; Shinohara, C.; Boynton, W. V.; Smith, P.] Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA.
[Sutter, B.; Lauer, H. V.; Golden, D. C.] ESCG, Houston, TX 77058 USA.
[Tamppari, L. K.; Gross, M.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[Stewart, R. L.] Corning Inc, Corning, NY 14831 USA.
RP Ming, DW (reprint author), NASA, ARES, Lyndon B Johnson Space Ctr, Mail Code KA,2101 NASA Pkwy, Houston, TX 77058 USA.
EM douglas.w.ming@nasa.gov
FU NASA; JSC; University of Arizona; Jacobs Engineering
FX DWM and RVM acknowledge support of the NASA Mars Phoenix Scout mission,
NASA Mars Fundamental Research Program, and the NASA Johnson Space
Center. We especially thank the support from the JSC curation staff in
the Astromaterials Research and Exploration Science Directorate and the
support from Corning Incorporated in the preparation of the Macor TM.
WVB, CS, and RW acknowledge support of the NASA Mars Phoenix Scout
mission and the University of Arizona. BS, DCG, and HVL acknowledge
support from Jacobs Engineering, NASA Mars Fundamental Research Program,
and the NASA Mars Phoenix Scout mission.
NR 9
TC 9
Z9 9
U1 0
U2 6
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 2169-9097
J9 J GEOPHYS RES-PLANET
JI J. Geophys. Res.-Planets
PD OCT 29
PY 2008
VL 113
AR E00A21
DI 10.1029/2007JE003061
PG 17
WC Geochemistry & Geophysics
SC Geochemistry & Geophysics
GA 368DS
UT WOS:000260602100001
ER
PT J
AU Xu, Y
Mahmood, M
Li, ZR
Dervishi, E
Trigwell, S
Zharov, VP
Ali, N
Saini, V
Biris, AR
Lupu, D
Boldor, D
Biris, AS
AF Xu, Yang
Mahmood, Meena
Li, Zhongrui
Dervishi, Enkeleda
Trigwell, Steve
Zharov, Vladimir P.
Ali, Nawab
Saini, Viney
Biris, Alexandru R.
Lupu, Dan
Boldor, Dorin
Biris, Alexandru S.
TI Cobalt nanoparticles coated with graphitic shells as localized radio
frequency absorbers for cancer therapy
SO NANOTECHNOLOGY
LA English
DT Article
ID MULTIWALLED CARBON NANOTUBES; MAGNETIC NANOPARTICLES; DRUG-DELIVERY;
CELLS; NANOCRYSTALS; DISPERSIONS; EXCITATION; PARTICLES; VECTOR; GOLD
AB Graphitic carbon-coated ferromagnetic cobalt nanoparticles (C-Co-NPs) with diameters of around 7 nm and cubic crystalline structures were synthesized by catalytic chemical vapor deposition. X-ray diffraction and x-ray photoelectron spectroscopy analysis indicated that the cobalt nanoparticles inside the carbon shells were preserved in the metallic state. Fluorescence microscopy images and Raman spectroscopy revealed effective penetrations of the C-Co-NPs through the cellular plasma membrane of the cultured HeLa cells, both inside the cytoplasm and in the nucleus. Low radio frequency (RF) radiation of 350 kHz induced localized heat into the metallic nanoparticles, which triggered the killing of the cells, a process that was found to be dependent on the RF application time and nanoparticle concentration. When compared to carbon nanostructures such as single-wall carbon nanotubes, these coated magnetic cobalt nanoparticles demonstrated higher specificity for RF absorption and heating. DNA gel electrophoresis assays of the HeLa cells after the RF treatment showed a strong broadening of the DNA fragmentation spectrum, which further proved the intense localized thermally induced damages such as DNA and nucleus membrane disintegration, under RF exposure in the presence of C-Co-NPs. The data presented in this report indicate a great potential of this new process for in vivo tumor thermal ablation, bacteria killing, and various other biomedical applications.
C1 [Xu, Yang; Mahmood, Meena; Li, Zhongrui; Dervishi, Enkeleda; Ali, Nawab; Saini, Viney; Biris, Alexandru S.] Univ Arkansas, Nanotechnol Ctr, Little Rock, AR 72204 USA.
[Xu, Yang; Mahmood, Meena; Li, Zhongrui; Dervishi, Enkeleda; Ali, Nawab; Saini, Viney; Biris, Alexandru S.] Univ Arkansas, Dept Appl Sci, Little Rock, AR 72204 USA.
[Trigwell, Steve] NASA, Electrostat & Surface Phys Lab, ASRC Aerosp, Kennedy Space Ctr, FL 32899 USA.
[Zharov, Vladimir P.] Univ Arkansas Med Sci, Philips Class Laser Labs, Little Rock, AR 72204 USA.
[Biris, Alexandru R.; Lupu, Dan] Natl Inst Res & Dev Isotop & Mol Technol, RO-3400 Cluj Napoca, Romania.
[Boldor, Dorin] Louisiana State Univ, AgCtr, Baton Rouge, LA 70803 USA.
RP Xu, Y (reprint author), Univ Arkansas, Nanotechnol Ctr, Little Rock, AR 72204 USA.
EM yxxu@ualr.edu; asbiris@ualr.edu
RI Biris, Alexandru/A-8507-2010; Lupu, Dan/C-3346-2009; Dervishi,
Enkeleda/B-2239-2010; Biris, Alexandru /C-4517-2011; Zharov,
Vladimir/J-9728-2013
NR 30
TC 46
Z9 46
U1 1
U2 24
PU IOP PUBLISHING LTD
PI BRISTOL
PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND
SN 0957-4484
J9 NANOTECHNOLOGY
JI Nanotechnology
PD OCT 29
PY 2008
VL 19
IS 43
AR 435102
DI 10.1088/0957-4484/19/43/435102
PG 9
WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary;
Physics, Applied
SC Science & Technology - Other Topics; Materials Science; Physics
GA 352HK
UT WOS:000259486700002
PM 21832683
ER
PT J
AU Cerruti, AP
Kintner, PM
Gary, DE
Mannucci, AJ
Meyer, RF
Doherty, P
Coster, AJ
AF Cerruti, Alessandro P.
Kintner, Paul M., Jr.
Gary, Dale E.
Mannucci, Anthony J.
Meyer, Robert F.
Doherty, Patricia
Coster, Anthea J.
TI Effect of intense December 2006 solar radio bursts on GPS receivers
SO SPACE WEATHER-THE INTERNATIONAL JOURNAL OF RESEARCH AND APPLICATIONS
LA English
DT Article
AB [1] Solar radio bursts during December 2006 were sufficiently intense to be measurable with GPS receivers. The strongest event occurred on 6 December 2006 and affected the operation of many GPS receivers. This event exceeded 1,000,000 solar flux unit and was about 10 times larger than any previously reported event. The strength of the event was especially surprising since the solar radio bursts occurred near solar minimum. The strongest periods of solar radio burst activity lasted a few minutes to a few tens of minutes and, in some cases, exhibited large intensity differences between L1 (1575.42 MHz) and L2 (1227.60 MHz). Civilian dual frequency GPS receivers were the most severely affected, and these events suggest that continuous, precise positioning services should account for solar radio bursts in their operational plans. This investigation raises the possibility of even more intense solar radio bursts during the next solar maximum that will significantly impact the operation of GPS receivers.
C1 [Cerruti, Alessandro P.; Kintner, Paul M., Jr.] Cornell Univ, Sch Elect & Comp Engn, Ithaca, NY 14853 USA.
[Gary, Dale E.] New Jersey Inst Technol, Ctr Solar Terr Res, Newark, NJ 07102 USA.
[Mannucci, Anthony J.; Meyer, Robert F.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[Doherty, Patricia] Boston Coll, Inst Sci Res, Chestnut Hill, MA 02467 USA.
[Coster, Anthea J.] MIT, Haystack Observ, Westford, MA 01886 USA.
RP Cerruti, AP (reprint author), Cornell Univ, Sch Elect & Comp Engn, Ithaca, NY 14853 USA.
EM apc20@cornell.edu; pmk1@cornell.edu; dale.e.gary@njit.edu;
tony.mannucci@jpl.nasa.gov; rfmeyer@jpl.nasa.gov; dohertpd@bc.edu;
ajc@haystack.mit.edu
OI Mannucci, Anthony/0000-0003-2391-8490; Gary, Dale/0000-0003-2520-8396
FU ONR [N00014-04-10105]; NSF [AST-0352915, AST-0607544]; NASA [NNG06GJ40G]
FX The research at Cornell University was supported by ONR grant
N00014-04-10105. We are grateful to Tom McHugh for providing the WAAS
amplitude data. OVSA and the research at NJIT were supported by NSF
grants AST-0352915 and AST-0607544 and NASA grant NNG06GJ40G. Portions
of the research for this paper were performed at the Jet Propulsion
Laboratory, California Institute of Technology, under contract with
NASA. The views reported here are solely the views of the authors and
not of the FAA or other government agencies.
NR 20
TC 21
Z9 21
U1 1
U2 5
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 1542-7390
J9 SPACE WEATHER
JI Space Weather
PD OCT 29
PY 2008
VL 6
IS 10
AR S10D07
DI 10.1029/2007SW000375
PG 10
WC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology &
Atmospheric Sciences
SC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology &
Atmospheric Sciences
GA 368EQ
UT WOS:000260604500001
ER
PT J
AU Holland, DE
Berglund, JA
Spruce, JP
Mckellip, RD
AF Holland, Donald E.
Berglund, Judith A.
Spruce, Joseph P.
Mckellip, Rodney D.
TI Derivation of Effective Aerodynamic Surface Roughness in Urban Areas
from Airborne Lidar Terrain Data
SO JOURNAL OF APPLIED METEOROLOGY AND CLIMATOLOGY
LA English
DT Article
ID LASER ALTIMETER MEASUREMENTS; LENGTH
AB An automated technique was developed that uses only airborne lidar terrain data to derive the necessary parameters for calculation of effective aerodynamic surface roughness in urban areas. The technique provides parameters for geometric models that have been used over the past 40 + years by automatically deriving the relevant geometry, orientation, and spacing of buildings and trees. In its prototypical form, this technique subsequently calculates an effective surface roughness for 1-km(2) parcels of land for each of five geometric models. The user can define several constraints to guide processing based on a priori knowledge of the urban area or lidar data characteristics. Any given wind direction ( or range of directions) can be selected to simulate conditions of variable wind flow and the impact on effective surface roughness. The operation, capabilities, and limitations of the technique were demonstrated using lidar terrain data from Broward County, Florida.
C1 [Holland, Donald E.; Berglund, Judith A.; Spruce, Joseph P.] Sci Syst & Applicat Inc, John C Stennis Space Ctr, MS 39529 USA.
[Mckellip, Rodney D.] NASA, John C Stennis Space Ctr, MS USA.
RP Holland, DE (reprint author), Sci Syst & Applicat Inc, Bldg 1105, John C Stennis Space Ctr, MS 39529 USA.
EM donald.e.holland@nasa.gov
NR 23
TC 6
Z9 7
U1 0
U2 5
PU AMER METEOROLOGICAL SOC
PI BOSTON
PA 45 BEACON ST, BOSTON, MA 02108-3693 USA
SN 1558-8424
J9 J APPL METEOROL CLIM
JI J. Appl. Meteorol. Climatol.
PD OCT 28
PY 2008
VL 47
IS 10
BP 2614
EP 2626
DI 10.1175/2008JAMC1751.1
PG 13
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 366HO
UT WOS:000260471600009
ER
PT J
AU Li, YD
Wang, Y
Song, Y
Hu, L
Gao, ST
Rong, F
AF Li Yaodong
Wang Yun
Song Yang
Hu Liang
Gao Shouting
Rong Fu
TI Characteristics of Summer Convective Systems Initiated over the Tibetan
Plateau. Part I: Origin, Track, Development, and Precipitation
SO JOURNAL OF APPLIED METEOROLOGY AND CLIMATOLOGY
LA English
DT Article
ID LATENT HEATING DISTRIBUTIONS; PASSIVE MICROWAVE RADIOMETRY; LARGE-SCALE
CIRCULATION; DIURNAL VARIABILITY; PROFILING ALGORITHM; SURROUNDING
AREAS; SATELLITE DATA; TRMM; RAINFALL; MECHANISMS
AB Summer convective systems (CSs) initiated over the Tibetan Plateau identified by the International Satellite Cloud Climatology Project (ISCCP) deep convection database and associated Tropical Rainfall Measuring Mission (TRMM) precipitation for 1998-2001 have been analyzed for their basic characteristics in terms of initiation, distribution, trajectory, development, life cycle, convective intensity, and precipitation. Summer convective systems have a dominant center over the Hengduan Mountain and a secondary center over the Yaluzangbu River Valley. Precipitation associated with these CSs contributes more than 60% of total precipitation over the central-eastern area of the Tibetan Plateau and 30%-40% over the adjacent region to its southeast. The average CS life cycle is about 36 h; 85% of CSs disappear within 60 h of their initiation. About 50% of CSs do not move out of the Tibetan region, with the remainder split into eastward and southward-moving components. These CSs moving out the Tibetan Plateau are generally larger, have longer life spans, and produce more rainfall than those staying inside the region. Convective system occurrences and associated rainfall present robust diurnal variations. The midafternoon maximum of CS initiation and associated rainfall over the plateau is mainly induced by solar heating linked to the unique Tibetan geography. The delayed afternoon-late night peak of rainfall from CSs propagating out of this region is a combined outcome of multiple mechanisms working together. Results suggest that interactions of summer Tibetan CSs with the orientation of the unique Tibetan geography and the surrounding atmospheric circulations are important for the development, intensification, propagation, and life span of these CSs.
C1 [Li Yaodong; Wang Yun; Hu Liang; Gao Shouting; Rong Fu] Chinese Acad Sci, Inst Atmospher Phys, Beijing, Peoples R China.
[Li Yaodong; Wang Yun] Beijing Aviat Meteorol Inst, Beijing, Peoples R China.
[Song Yang] George Mason Univ, Coll Sci, Fairfax, VA 22030 USA.
[Rong Fu] Georgia Inst Technol, Sch Earth & Atmospher Sci, Atlanta, GA 30332 USA.
RP Song, Y (reprint author), NASA, Goddard Space Flight Ctr, Code 613-1, Greenbelt, MD 20771 USA.
EM ysong@agnes.gsfc.nasa.gov
FU National Natural Science Foundation of China [40428002, 40633018]; NASA
TRMM; Global Precipitation Measurement (GPM); NASA Aura project
FX The authors thank ISCCP for distribution of the convective tracking
database and TRMM Data Information System (TSDIS) at NASA Goddard Space
Flight Center (GSFC) for providing 3B42 and 2A25 rainfall datasets. They
are grateful for the constructive comments from three anonymous
reviewers to improve the quality of this paper. The authors are
supported by the National Natural Science Foundation of China with two
grants (40428002 and 40633018), except Song Yang who was supported by
the NASA TRMM and Global Precipitation Measurement (GPM) projects. Rong
Fu is also supported by the NASA Aura project. A careful editing of the
English in the manuscript by Karen Mitchell at NASA GSFC is appreciated.
NR 75
TC 14
Z9 20
U1 0
U2 9
PU AMER METEOROLOGICAL SOC
PI BOSTON
PA 45 BEACON ST, BOSTON, MA 02108-3693 USA
SN 1558-8424
J9 J APPL METEOROL CLIM
JI J. Appl. Meteorol. Climatol.
PD OCT 28
PY 2008
VL 47
IS 10
BP 2679
EP 2695
DI 10.1175/2008JAMC1695.1
PG 17
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 366HO
UT WOS:000260471600013
ER
PT J
AU Joughin, I
Howat, IM
Fahnestock, M
Smith, B
Krabill, W
Alley, RB
Stern, H
Truffer, M
AF Joughin, Ian
Howat, Ian M.
Fahnestock, Mark
Smith, Ben
Krabill, William
Alley, Richard B.
Stern, Harry
Truffer, Martin
TI Continued evolution of Jakobshavn Isbrae following its rapid speedup
SO JOURNAL OF GEOPHYSICAL RESEARCH-EARTH SURFACE
LA English
DT Article
ID GREENLAND ICE-SHEET; FRACTURE-MECHANICS APPROACH; WEST GREENLAND; OUTLET
GLACIERS; SEA-ICE; FLOW; ACCELERATION; DEFORMATION; VELOCITY; BALANCE
AB [1] Several new data sets reveal that thinning and speedup of Jakobshavn Isbrae continue, following its recent rapid increase in speed as its floating ice tongue disintegrated. The present speedup rate of similar to 5% a(-1) over much of the fast-moving region appears to be a diffusive response to the initial much larger speedup near the front. There is strong seasonality in speed over much of the fast-flowing main trunk that shows a good inverse correlation with the seasonally varying length of a short ( typically similar to 6 km) floating ice tongue. This modulation of speed with ice front position supports the hypothesis that the major speedup was caused by loss of the larger floating ice tongue from 1998 to 2003. Analysis of image time series suggests that the transient winter ice tongue is formed when sea ice bonds glacier ice in the fjord to produce a nearly rigid mass that almost entirely suppresses calving. Major calving only resumes in late winter when much of this ice clears from the fjord. The collapse of the ice tongue in the late 1990s followed almost immediately after a sharp decline in winter sea-ice concentration in Disko Bay. This decline may have extended the length of the calving season for several consecutive years, leading to the ice tongue's collapse.
C1 [Joughin, Ian; Smith, Ben; Stern, Harry] Univ Washington, Appl Phys Lab, Polar Sci Ctr, Seattle, WA 98105 USA.
[Howat, Ian M.] Ohio State Univ, Sch Earth Sci, Bryd Polar Res Ctr, Columbus, OH 43210 USA.
[Fahnestock, Mark] Univ New Hampshire, Inst Study Earth Oceans & Space, Durham, NH 03824 USA.
[Krabill, William] NASA, Goddard Space Flight Ctr, Cryospher Sci Branch, Wallops Flight Facil, Wallops Isl, VA 23337 USA.
[Alley, Richard B.] Penn State Univ, Dept Geosci, University Pk, PA 16802 USA.
[Alley, Richard B.] Penn State Univ, Earth & Environm Syst Inst, University Pk, PA 16802 USA.
[Truffer, Martin] Univ Alaska Fairbanks, Inst Geophys, Fairbanks, AK 99775 USA.
[Truffer, Martin] ETH, Zurich, Switzerland.
RP Joughin, I (reprint author), Univ Washington, Appl Phys Lab, Polar Sci Ctr, 1013 NE 40th St, Seattle, WA 98105 USA.
EM ian@apl.washington.edu; rba6@psu.edu
RI Howat, Ian/A-3474-2008; Joughin, Ian/A-2998-2008; Fahnestock,
Mark/N-2678-2013
OI Howat, Ian/0000-0002-8072-6260; Joughin, Ian/0000-0001-6229-679X;
FU National Science Foundation (NSF) [ARC0531270, ARC0531250, ARC0531211,
ARC0531133, ARC0531075, 0424589]; National Aerospace Administration
[NNG06GE5SG, NNG06GB37G]
FX The National Science Foundation (NSF) supported contributions by I.
Joughin (ARC0531270), M. Fahnestock (ARC0531250), R. Alley (ARC0531211),
H. Stern (ARC0531133), and M. Truffer (ARC0531075) through Arctic System
Science Grants. The National Aerospace Administration supported I.
Howat's, B. Smith's (NNG06GE5SG), and W. Krabill's contributions. Work
by R. Alley was also partially supported by NSF 0424589 and NASA
NNG06GB37G. The RADARSAT data were acquired by the Canadian Space Agency
and downlinked and distributed by the Alaska Satellite Facility.
Comments by G. Hamilton, A. Vieli, B. Csatho, and an anonymous reviewer
led to substantial improvements in the final manuscript.
NR 54
TC 107
Z9 107
U1 1
U2 21
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0148-0227
J9 J GEOPHYS RES-EARTH
JI J. Geophys. Res.-Earth Surf.
PD OCT 28
PY 2008
VL 113
IS F4
AR F04006
DI 10.1029/2008JF001023
PG 14
WC Geosciences, Multidisciplinary
SC Geology
GA 368CX
UT WOS:000260600000001
ER
PT J
AU Tamppari, LK
Barnes, J
Bonfiglio, E
Cantor, B
Friedson, AJ
Ghosh, A
Grover, MR
Kass, D
Martin, TZ
Mellon, M
Michaels, T
Murphy, J
Rafkin, SCR
Smith, MD
Tsuyuki, G
Tyler, D
Wolff, M
AF Tamppari, Leslie K.
Barnes, Jeffrey
Bonfiglio, Eugene
Cantor, Bruce
Friedson, A. James
Ghosh, Amitabha
Grover, M. Rob
Kass, David
Martin, Terry Z.
Mellon, Michael
Michaels, Tim
Murphy, Jim
Rafkin, Scot C. R.
Smith, Michael D.
Tsuyuki, Glenn
Tyler, Daniel, Jr.
Wolff, Michael
TI Expected atmospheric environment for the Phoenix landing season and
location
SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS
LA English
DT Article
ID INTERANNUAL VARIABILITY; MGS TES; MARS; SITES; MODEL; TEMPERATURES;
SIMULATIONS; PATHFINDER; TURBULENCE; ORBITER
AB The Phoenix mission, launched on 4 August 2007, landed in the far northern plains of Mars on 25 May 2008. In order to prepare for the landing events and the 90-sol mission, a significant amount of work has gone into characterizing the atmospheric environment at this location on Mars for northern late spring through midsummer. In this paper we described the motivation for the work and present our results on atmospheric densities and winds expected during the Phoenix entry, descent, and landing optical depth expected over the course of the science mission.
C1 [Tamppari, Leslie K.; Bonfiglio, Eugene; Friedson, A. James; Grover, M. Rob; Kass, David; Martin, Terry Z.; Tsuyuki, Glenn] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[Barnes, Jeffrey; Tyler, Daniel, Jr.] Oregon State Univ, Coll Ocean & Atmospher Sci, Corvallis, OR 97331 USA.
[Cantor, Bruce] Malin Space Sci Syst Inc, San Diego, CA 92121 USA.
[Ghosh, Amitabha] Tharsis Inc, Gaithersburg, MD 20877 USA.
[Mellon, Michael] Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80309 USA.
[Michaels, Tim; Rafkin, Scot C. R.] SW Res Inst, Boulder, CO 80302 USA.
[Murphy, Jim] New Mexico State Univ, Dept Astron, Las Cruces, NM 88003 USA.
[Smith, Michael D.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
[Wolff, Michael] Space Sci Inst, Boulder, CO 80301 USA.
[Smith, Michael D.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
RP Tamppari, LK (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM leslie.tamppari@jpl.nasa.gov
RI Smith, Michael/C-8875-2012; Mellon, Michael/C-3456-2016
FU NASA; Oregon State University; Southwest Research Institute
FX This work was carried out at JPL/Caltech through a contract from NASA
and at Oregon State University and Southwest Research Institute via
contracts from JPL/Caltech.
NR 38
TC 16
Z9 16
U1 0
U2 2
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 2169-9097
EI 2169-9100
J9 J GEOPHYS RES-PLANET
JI J. Geophys. Res.-Planets
PD OCT 28
PY 2008
VL 113
AR E00A20
DI 10.1029/2007JE003034
PG 18
WC Geochemistry & Geophysics
SC Geochemistry & Geophysics
GA 368DR
UT WOS:000260602000001
ER
PT J
AU Du, AM
Tsurutani, BT
Sun, W
AF Du, A. M.
Tsurutani, B. T.
Sun, W.
TI Anomalous geomagnetic storm of 21-22 January 2005: A storm main phase
during northward IMFs
SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
LA English
DT Article
ID MAGNETIC STORMS; SOLAR-WIND; INTERPLANETARY SHOCKS; MAGNETOSPHERE; DST;
DISCONTINUITIES; MAGNETOTAIL; ORIGIN; DECAY; FIELD
AB The major (minimum Dst = -105nT) magnetic storm which occurred on 21-22 January 2005 is highly anomalous because the storm main phase (identified by the SYM-H indices) developed during northward interplanetary magnetic fields (IMFs). We believe this to be the first event of its type to be reported in the literature. Interplanetary ACE and Cluster C1 data are used for solar wind diagnostics, and LANL 90 and 97, GOES 10 and 12 and GEOTAIL data are used for magnetospheric diasgnostics. An unusually strong (magnetosonic Mach number equal to 5.4) shoch detected at similar to 1674 UT, 21 January 2005 by ACE causes a SI+ (of 57 nT) at similar to 1712 UT at Earth. Southward magnetic fields in the sheath following the shock caused a decrease of SYM-H with a peak value similar to-41 nT. A dynamic pressure jump across a double discontinuity in the solar wind at 1823 UT observed by ACE induced a second SI+ (of 25 nT) at 1847 UT at Earth. Southward magnetic fields following this event led to a second SYM-H decrease with peak intensity -2 nT. However, when the storm main phase developed starting at 1946 UT, the IMF Bz turned northward. The IMF was northward form the portion of the main phase from similar to 1946 UT to 0124 UT (almost 6 h). By comparing solar wind energy input current (represented by the integrated SYM-H), we arrive at a possible explanation that there is first energy storage in the magnetotail and the delayed energy injection (after storage in the magnetotail) into the magnetospphere. Other interpretations/mechanisms are possible.
C1 [Du, A. M.] Chinese Acad Sci, Inst Geol & Geophys, Beijing 100029, Peoples R China.
[Tsurutani, B. T.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[Sun, W.] Univ Alaska Fairbanks, Inst Geophys, Fairbanks, AK 99775 USA.
RP Du, AM (reprint author), Chinese Acad Sci, Inst Geol & Geophys, Beijing 100029, Peoples R China.
EM amdu@mail.igcas.ac.cn
FU MOST [2006CB806305]; NSFC [40774086]
FX We appreciate discussions with Gordon Rostoker. We acknowledge the
CDAWeb for access to the Cluster, Wind, GOES10 and GOES12 data. SOPA
energitic proton and electorn spin-averaged differential flux
measurements are afforded by Los Alamos National Laboratory. The SYMH,
AE data are provided by the World Data Center for Geomagnetism at Kyoto
University. This work was supported by MOST 973 Plan (2006CB806305) and
NSFC (40774086). Portions of the work were performed at the Jet
Propulsion Laboratory, California Institute of Technology, under
contract with NASA.
NR 38
TC 46
Z9 50
U1 1
U2 9
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0148-0227
J9 J GEOPHYS RES-SPACE
JI J. Geophys. Res-Space Phys.
PD OCT 28
PY 2008
VL 113
IS A10
AR A10214
DI 10.1029/2008JA013284
PG 9
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 368EI
UT WOS:000260603700001
ER
PT J
AU Webber, WR
Cummings, AC
McDonald, FB
Stone, EC
Heikkila, B
Lal, N
AF Webber, W. R.
Cummings, A. C.
McDonald, F. B.
Stone, E. C.
Heikkila, B.
Lal, N.
TI Galactic cosmic ray H and He nuclei energy spectra measured by Voyagers
1 and 2 near heliospheric termination shock in positive and negative
solar magnetic polarity cycles
SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
LA English
DT Article
ID MODULATION
AB Using data from the Voyager 1 and 2 spacecraft, we have followed the intensity variations of H, He and C + O nuclei between 1998 and 2008 and determined the spectra for H and He at the time of minimum modulation in 1998, when the solar magnetic polarity was positive and agian in 2008 when the solar magnetic polarity was negative. At these times these data are representative of conditions near a heliospheric termination shoch assumed to be located at similar to 90 AU. Above similar to 400MeV/nuc for He nuclei the 11-year solar modulation cycle observed at the Earth is not seen; instead there is a 22-year variation. The negative polarity cycle intensities above similar to 150 MeV/nuc are higher than those in the positive polarity cycle by factor of 1.4-1.7 times for both H and He nuclei. Below similar to 100 MeV/nuc the C nuclei intensities are similar in the two cycles to within +/- 10%. These observations are compared with theoretical calculations which also show a negative to positive polarity cycle intensity difference at higher energies, most likely associated with energy changes due to drifts near the termination shock, but the comparison suggests that improved estimates of the local interstellar spectra are required.
C1 [Webber, W. R.] New Mexico State Univ, Dept Astron, Las Cruces, NM 88003 USA.
[Cummings, A. C.; Stone, E. C.] CALTECH, Downs Lab, Pasadena, CA 91125 USA.
[McDonald, F. B.] Univ Maryland, Inst Phys Sci & Technol, College Pk, MD 20742 USA.
[Heikkila, B.; Lal, N.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
RP Webber, WR (reprint author), New Mexico State Univ, Dept Astron, Las Cruces, NM 88003 USA.
EM bwebber@nmsu.edu
NR 14
TC 17
Z9 17
U1 0
U2 0
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0148-0227
J9 J GEOPHYS RES-SPACE
JI J. Geophys. Res-Space Phys.
PD OCT 28
PY 2008
VL 113
IS A10
AR A10108
DI 10.1029/2008JA013395
PG 5
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 368EI
UT WOS:000260603700002
ER
PT J
AU Lyatskaya, S
Lyatsky, W
Khazanov, GV
AF Lyatskaya, Sonya
Lyatsky, W.
Khazanov, G. V.
TI Relationship between substorm activity and magnetic disturbances in two
polar caps
SO GEOPHYSICAL RESEARCH LETTERS
LA English
DT Article
ID FIELD-ALIGNED CURRENTS; SATELLITE
AB We examined the effect of magnetic disturbances in two polar caps on the generation of magnetospheric substorms. For this purpose we investigated the correlation between the AL index (showing substorm activity in the Northern hemisphere) and two geomagnetic activity indices, the Polar Cap (PC) index and Polar Magnetic (PM) index showing the magnetic disturbances in the Northern and Southern polar caps. For the analysis we used the data for four years when geomagnetic activity indices were available in both hemispheres. We obtained an unexpected yet important result: while in northern winter the correlation between AL index and northern PC/PM indices is very good, in northern summer the AL index correlates much better with southern PC/PM indices. Thus, substorm activity in summer months correlates much better with geomagnetic activity not in the nearby polar cap but in the opposite polar cap. This effect may be caused by the interhemispheric field-aligned currents flowing from the summer high-latitude ionosphere and closing through the ionosphere in the opposite auroral zone. An interesting feature of these interhemispheric currents is that they are directed opposite to the substorm field-aligned currents in the summer hemisphere but along the substorm field-aligned currents in the winter hemisphere. This leads to decreasing the total field-aligned currents and their contribution to magnetic disturbances in the summer hemisphere but increasing these currents and related magnetic disturbances in winter hemisphere, which explains the experimental results obtained in our study. Citation: Lyatskaya, S., W. Lyatsky, and G. V. Khazanov (2008), Relationship between substorm activity and magnetic disturbances in two polar caps, Geophys. Res. Lett., 35, L20104, doi: 10.1029/2008GL035187.
C1 [Lyatskaya, Sonya] Alabama A&M Univ, Dept Phys, Normal, AL 35762 USA.
[Lyatsky, W.; Khazanov, G. V.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
RP Lyatskaya, S (reprint author), Alabama A&M Univ, Dept Phys, 4900 Meridian St, Normal, AL 35762 USA.
EM lyatsky@hotmail.com
RI feggans, john/F-5370-2012
FU NASA HQ POLAR Project; NASA LWS Program
FX We gratefully acknowledge efforts of the staff of the World Data Center
for Geomagnetism in Kyoto, Japan, the Solar System Data Center in
Chilton, U. K., and World Data Center for Solar-Terrestrial Physics in
Moscow, Russia, in providing geomagnetic activity indices. This research
was performed while Wladislaw Lyatsky held a NASA Senior Postdoctoral
Program appointment at NASA/MSFC. Funding in support of this study was
provided partially by NASA HQ POLAR Project and NASA LWS Program.
NR 22
TC 13
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U1 0
U2 3
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0094-8276
J9 GEOPHYS RES LETT
JI Geophys. Res. Lett.
PD OCT 25
PY 2008
VL 35
IS 20
AR L20104
DI 10.1029/2008GL035187
PG 4
WC Geosciences, Multidisciplinary
SC Geology
GA 365GX
UT WOS:000260395000003
ER
PT J
AU Saur, J
Schilling, N
Neubauer, FM
Strobel, DF
Simon, S
Dougherty, MK
Russell, CT
Pappalardo, RT
AF Saur, Joachim
Schilling, Nico
Neubauer, Fritz M.
Strobel, Darrell F.
Simon, Sven
Dougherty, Michele K.
Russell, Christopher T.
Pappalardo, Robert T.
TI Evidence for temporal variability of Enceladus' gas jets: Modeling of
Cassini observations
SO GEOPHYSICAL RESEARCH LETTERS
LA English
DT Article
ID SATURNS PLASMA; PLUME; ATMOSPHERE; FRACTURES; ORIGIN; DUST
AB Time variability of Enceladus' gas plume is deduced from a joint investigation of Cassini spacecraft magnetic field data obtained during the first three flybys E0, E1 and E2 and neutral density measurements during the E2 flyby with a model that describes Enceladus' plasma interaction with individual jets. We infer a total plume content of similar to 7 x 10(32) H(2)O molecules corresponding to a mass loss rate of similar to 1600 kg/s for the E0 flyby and similar to 9 x 10(31) H(2)O molecules corresponding to a mass loss of similar to 200 kg/s for the E1 and E2 flybys. The magnetic field measurements also support upstream/downstream changes of the plume activity locations. On the first three Enceladus flybys Cassini did not fly through the densest parts of the plumes, which were a factor of 10-100 times higher at the same altitudes. Citation: Saur, J., N. Schilling, F. M. Neubauer, D. F. Strobel, S. Simon, M. K. Dougherty, and C. T. Russell (2008), Evidence for temporal variability of Enceladus' gas jets: Modeling of Cassini observations, Geophys. Res. Lett., 35, L20105, doi: 10.1029/2008GL035811.
C1 [Saur, Joachim; Schilling, Nico; Neubauer, Fritz M.; Simon, Sven] Univ Cologne, Inst Geophys & Meteorol, D-50923 Cologne, Germany.
[Dougherty, Michele K.] Univ London Imperial Coll Sci Technol & Med, Blackett Lab, London SW7 2BZ, England.
[Pappalardo, Robert T.] CALTECH, Jet Prop Lab, Pasadena, CA 91011 USA.
[Russell, Christopher T.] Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA 90095 USA.
[Strobel, Darrell F.] Johns Hopkins Univ, Dept Earth & Planetary Sci, Baltimore, MD 21218 USA.
[Saur, Joachim; Schilling, Nico; Neubauer, Fritz M.; Simon, Sven] Univ Cologne, Inst Geophys & Meteorol, D-5000 Cologne, Germany.
[Simon, Sven] Tech Univ Carolo Wilhelmina Braunschweig, Inst Theoret Phys, Braunschweig, Germany.
RP Saur, J (reprint author), Univ Cologne, Inst Geophys & Meteorol, Albertus Magnus Pl 1, D-50923 Cologne, Germany.
EM saur@geo.uni-koeln.de
RI Simon, Sven/M-2066-2014
FU Deutsche Forschungsgesellschaft; DLR; Cassini-Huygens Mission through
JPL [961155]; NASA [NNG05GO91G]
FX We thank Krishan Khurana for providing us with updated magnetic field
observations. J.S. and N.S. acknowledge support by Deutsche
Forschungsgesellschaft. F.M.N. and N.S. acknowledge support by DLR
through the Cassini project. D.F.S. acknowledges support by the
Cassini-Huygens Mission through JPL contract 961155 and NASA grant
NNG05GO91G.
NR 25
TC 49
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U1 0
U2 5
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0094-8276
J9 GEOPHYS RES LETT
JI Geophys. Res. Lett.
PD OCT 25
PY 2008
VL 35
IS 20
AR L20105
DI 10.1029/2008GL035811
PG 5
WC Geosciences, Multidisciplinary
SC Geology
GA 365GX
UT WOS:000260395000007
ER
PT J
AU Goldstein, ME
Sescu, A
AF Goldstein, M. E.
Sescu, Adrian
TI Boundary-layer transition at high free-stream disturbance levels -
beyond Klebanoff modes
SO JOURNAL OF FLUID MECHANICS
LA English
DT Article
ID NUMERICAL-METHODS; UPSTREAM FLOW; STOKES LAYER; INSTABILITY; TURBULENCE;
VORTICITY; DISTORTION; WAVES
AB We consider a nominally uniform flow over a semi-infinite flat plate and show how a small slowly modulated (predominantly streamwise) disturbance of the upstream flow is amplified by leading-edge bluntness effects and eventually develops into a small-amplitude but nonlinear spanwise motion far downstream from the edge. This motion is then imposed on the viscous boundary layer at the surface of the plate causing an order-one change in its profile shape, which can reduce the wall shear to zero and thereby causes the boundary layer to separate. The present study is similar to an earlier steady flow analysis, but the unsteady effects now cause the upstream boundary layer to develop inflectional profiles which can support rapidly growing inviscid instabilities that give rise to transition before the separation can occur.
C1 [Goldstein, M. E.] NASA, Glenn Res Ctr, Cleveland, OH 44135 USA.
[Sescu, Adrian] Univ Toledo, Dept Mech Ind & Mfg Engn, Toledo, OH 43606 USA.
RP Goldstein, ME (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA.
NR 33
TC 14
Z9 14
U1 0
U2 4
PU CAMBRIDGE UNIV PRESS
PI NEW YORK
PA 32 AVENUE OF THE AMERICAS, NEW YORK, NY 10013-2473 USA
SN 0022-1120
J9 J FLUID MECH
JI J. Fluid Mech.
PD OCT 25
PY 2008
VL 613
BP 95
EP 124
DI 10.1017/S0022112008003078
PG 30
WC Mechanics; Physics, Fluids & Plasmas
SC Mechanics; Physics
GA 366LD
UT WOS:000260481900005
ER
PT J
AU Ovchinnikov, V
Choudhari, MM
Piomelli, U
AF Ovchinnikov, Victor
Choudhari, Meelan M.
Piomelli, Ugo
TI Numerical simulations of boundary-layer bypass transition due to
high-amplitude free-stream turbulence
SO JOURNAL OF FLUID MECHANICS
LA English
DT Article
ID ORR-SOMMERFELD EQUATION; DISTURBANCE GROWTH; FLOW; MODEL; SCALE; GRIDS;
SPOT
AB Direct numerical simulations (DNS) of bypass transition due to high-amplitude free-stream turbulence (FST) are carried out for a flat-plate boundary layer. The computational domain begins upstream of the plate leading edge and extends into the fully turbulent region. Thus, there is no ad hoc treatment to account for the initial ingestion of FST into the laminar boundary layer. We study the effects of both the FST length scale and the disturbance behaviour near the plate leading edge on the details of bypass transition farther downstream. In one set of simulations, the FST parameters are chosen to match the ERCOFTAC benchmark case T3B. The inferred FST integral length scale L-11 is significantly larger (R-L=UL11/nu=6580) than that employed in previous simulations of bypass transition (R-L similar or equal to 1000). An additional set of simulations was performed at R-L = 1081 to compare the transition behaviour in the T3B case with that of a smaller value of FST length scale. The FST length scale is found to have a profound impact on the mechanism of transition. While strearnwise streaks (Klebanoff modes) are observed at both values of the FST length scale, they appear to have clear dynamical significance only at the smaller value of R-L, where transition is concomitant with streak breakdown. For the T3B case, turbulent spots form upstream of the region where streaks could be detected. Spot precursors are traced to quasi-periodic spanwise structures, first observed as short wavepackets in the wall-normal velocity component inside the boundary layer. These structures are reoriented to become horseshoe vortices, which break down into young turbulent spots. Two of the four spots examined for this case had a downstream-pointing shape, similar to those found in experimental studies of transitional boundary layers. Additionally, our simulations indicate the importance of leading-edge receptivity for the onset of transition. Specifically, higher fluctuations of the vertical velocity at the leading edge of the plate result in higher levels of streamwise Reynolds stress inside the developing boundary layer, facilitating breakdown to turbulence.
C1 [Ovchinnikov, Victor] MIT, Dept Chem Engn, Cambridge, MA 02139 USA.
[Choudhari, Meelan M.] NASA, Langley Res Ctr, Hampton, VA 23681 USA.
[Piomelli, Ugo] Univ Maryland, Dept Mech Engn, College Pk, MD 20742 USA.
RP Ovchinnikov, V (reprint author), MIT, Dept Chem Engn, 77 Massachusetts Ave, Cambridge, MA 02139 USA.
RI Choudhari, Meelan/F-6080-2017
OI Choudhari, Meelan/0000-0001-9120-7362
FU NASA Langley Research Center [NAG12285]
FX V. O. and U. P. acknowledge the financial support of the NASA Langley
Research Center under Cooperative Agreement NAG12285. Thanks are also
due to Dr Jens Fransson for sharing with us the results of flow
visualizations based on wind tunnel experiments at KTH, Stockholm.
Finally, we are grateful to an anonymous reviewer for clarification of
experimental techniques for measuring Reynolds stress near the wall.
NR 50
TC 30
Z9 30
U1 0
U2 14
PU CAMBRIDGE UNIV PRESS
PI NEW YORK
PA 32 AVENUE OF THE AMERICAS, NEW YORK, NY 10013-2473 USA
SN 0022-1120
J9 J FLUID MECH
JI J. Fluid Mech.
PD OCT 25
PY 2008
VL 613
BP 135
EP 169
DI 10.1017/S0022112008003017
PG 35
WC Mechanics; Physics, Fluids & Plasmas
SC Mechanics; Physics
GA 366LD
UT WOS:000260481900007
ER
PT J
AU Woods, CP
Waliser, DE
Li, JL
Austin, RT
Stephens, GL
Vane, DG
AF Woods, Christopher P.
Waliser, Duane E.
Li, Jui-Lin
Austin, Richard T.
Stephens, Graeme L.
Vane, Deborah G.
TI Evaluating CloudSat ice water content retrievals using a cloud-resolving
model: Sensitivities to frozen particle properties
SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
LA English
DT Article
ID SIZE DISTRIBUTIONS; MESOSCALE MODEL; PRECIPITATION PARTICLES; RADAR
MEASUREMENTS; STRATIFORM CLOUDS; WINTER STORMS; CIRRUS CLOUDS; SNOW;
CLIMATE; EARTH
AB The A-Train satellite constellation has dramatically increased the temporal and spatial coverage of atmospheric ice water content estimates. The new data are derived by retrieval algorithms designed to estimate atmospheric cloud ice water content from remotely sensed measurements. Such retrieval algorithms rely on simplifying assumptions regarding the characteristics of ice particles in the atmosphere. In this study, the sensitivities of CloudSat ice water content retrievals to frozen particle characteristics are tested by generating CloudSat-like retrievals from profiles of known ice water content. CloudSat actively measures vertical profiles of radar reflectivity in clouds with a 94-GHz cloud-profiling radar. Ice water content is retrieved in each cloudy profile at temperatures below 0 degrees C. To assess the CloudSat radar-only ice water content retrieval algorithm (version 5.0 in Release 3 [R03] and version 5.1 in Release 4 [R04] of 2B-CWC-RO), we apply a 94-GHz reflectivity simulator to profiles of ice water content generated by a cloud-resolving numerical model and comprising various frozen particle species (ice, snow, and graupel). The CloudSat ice water content retrieval algorithm is applied to the profiles of simulated reflectivity, and the results are compared to the modeled profiles of known frozen water mass. The results from each version of the algorithm are shown to be sensitive to the characteristics of the frozen particle size distributions and particle densities. Tests of version 5.0 indicate that height varying information could improve retrievals. Despite the addition of a height varying component implemented in version 5.1, similar positive biases are indicated in the tests of each algorithm.
C1 [Woods, Christopher P.; Waliser, Duane E.; Li, Jui-Lin; Vane, Deborah G.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[Austin, Richard T.; Stephens, Graeme L.] Colorado State Univ, Dept Atmospher Sci, Ft Collins, CO 80523 USA.
RP Woods, CP (reprint author), CALTECH, Jet Prop Lab, MS 183-501,4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM cp.woods@gmail.com
NR 59
TC 13
Z9 13
U1 0
U2 5
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 2169-897X
J9 J GEOPHYS RES-ATMOS
JI J. Geophys. Res.-Atmos.
PD OCT 25
PY 2008
VL 113
IS D20
AR D00A11
DI 10.1029/2008JD009941
PG 16
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 365GK
UT WOS:000260393700002
ER
PT J
AU Forbes, KF
St Cyr, OC
AF Forbes, Kevin F.
St Cyr, O. C.
TI Solar activity and economic fundamentals: Evidence from 12
geographically disparate power grids
SO SPACE WEATHER-THE INTERNATIONAL JOURNAL OF RESEARCH AND APPLICATIONS
LA English
DT Article
ID GEOMAGNETICALLY INDUCED CURRENTS; DISTURBANCES; SYSTEMS; INDUCTION
AB This study uses local (ground-based) magnetometer data as a proxy for geomagnetically induced currents (GICs) to address whether there is a space weather/electricity market relationship in 12 geographically disparate power grids: Eirgrid, the power grid that serves the Republic of Ireland; Scottish and Southern Electricity, the power grid that served northern Scotland until April 2005; Scottish Power, the power grid that served southern Scotland until April 2005; the power grid that serves the Czech Republic; E. ON Netz, the transmission system operator in central Germany; the power grid in England and Wales; the power grid in New Zealand; the power grid that serves the vast proportion of the population in Australia; ISO New England, the power grid that serves New England; PJM, a power grid that over the sample period served all or parts of Delaware, Maryland, New Jersey, Ohio, Pennsylvania, Virginia, West Virginia, and the District of Columbia; NYISO, the power grid that serves New York State; and the power grid in the Netherlands. This study tests the hypothesis that GIC levels (proxied by the time variation of local magnetic field measurements (dH/dt)) and electricity grid conditions are related using Pearson's chi-squared statistic. The metrics of power grid conditions include measures of electricity market imbalances, energy losses, congestion costs, and actions by system operators to restore grid stability. The results of the analysis indicate that real-time market conditions in these power grids are statistically related with the GIC proxy.
C1 [Forbes, Kevin F.] Catholic Univ Amer, Dept Econ & Business, Washington, DC 20064 USA.
[St Cyr, O. C.] Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA.
[St Cyr, O. C.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
RP Forbes, KF (reprint author), Catholic Univ Amer, Dept Econ & Business, Washington, DC 20064 USA.
OI Forbes, Kevin/0000-0002-9521-6845
FU National Science Foundation [ATM-0318582]
FX This research was made possible by a grant from the National Science
Foundation ( award ATM-0318582). Earlier versions of the paper were
presented at the April 2007 International Industrial Organization
Conference in Savannah, Georgia, and the 2007 Space Weather Workshop in
Boulder, Colorado. Thanks go to the participants of these sessions for
their constructive criticism and helpful suggestions. We thank the
editor and three anonymous reviewers for their helpful comments and
suggestions. We thank Antti Pulkkinen for his technical critique and
Michael A. Forbes for writing the programs that manipulated the large
quantity of geomagnetic data used in this study. We thank the system
operators of the power grids for making their data available and for
answering our questions. We also thank the British Geological Survey,
the Geological Survey of Canada, GeoForschungsZentrum Potsdam, the
Geophysical Institute of the Academy of Sciences of the Czech Republic,
Geoscience Australia, the Institute of Geological and Nuclear Sciences
Ltd., the Royal Meteorological Institute of Belgium, and the United
States Geological Survey. The geomagnetic data provided by these
organizations were critical to the analysis. We also thank Intermagnet (
www. intermagnet. org) for promoting high standards of magnetic
observatory practice, an efficient mechanism for the distribution of
this data. Any errors are the full responsibility of the authors.
NR 37
TC 14
Z9 14
U1 1
U2 6
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 1542-7390
J9 SPACE WEATHER
JI Space Weather
PD OCT 25
PY 2008
VL 6
IS 10
AR S10003
DI 10.1029/2007SW000350
PG 20
WC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology &
Atmospheric Sciences
SC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology &
Atmospheric Sciences
GA 365FA
UT WOS:000260390100001
ER
PT J
AU Choi, Y
Wang, Y
Zeng, T
Cunnold, D
Yang, ES
Martin, R
Chance, K
Thouret, V
Edgerton, E
AF Choi, Yunsoo
Wang, Yuhang
Zeng, Tao
Cunnold, Derek
Yang, Eun-Su
Martin, Randall
Chance, Kelly
Thouret, Valerie
Edgerton, Eric
TI Springtime transitions of NO2, CO, and O-3 over North America: Model
evaluation and analysis
SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
LA English
DT Article
ID GENERAL-CIRCULATION MODEL; MOZAIC AIRBORNE PROGRAM; HIGH-LATITUDES;
TROPOSPHERIC OZONE; WATER-VAPOR; REACTIVE NITROGEN; DATA ASSIMILATION;
ART.; TOPSE; TRANSPORT
AB Surface observations from AIRNow and Southeastern Aerosol Research and Characterization Study networks, aircraft observations from the Measurement of Ozone and Water Vapor by Airbus In-Service Aircraft program, ozonesondes, and remote sensing measurements from Global Ozone Mapping Experiment, Total Ozone Mapping Spectrometer (TOMS), and Stratospheric Aerosol and Gas Experiment (SAGE) II for February-May 2000 over North America are used to characterize the springtime transitions of O-3 and its precursors. These measurements provide a comprehensive data set to evaluate the performance of the 3-D Regional Chemical Transport Model (REAM). The model is then applied to analyze the key factors affecting the springtime transitions of trace gas concentrations and export. The global GEOS-CHEM model is used to provide chemical initial and boundary conditions. Generally, the model results are in good agreement with the observations in the troposphere except for a low bias of upper tropospheric O-3; the bias decreases toward the summer and lower latitudes. The rate of observed surface O-3 increase in spring is simulated well by REAM. It is overestimated by GEOS-CHEM over the eastern United States. A key factor driving the model difference is daytime mixing depth. A shallow boundary layer in REAM leads to more efficient removal of radicals and hence slower activation of photochemistry in spring, when the primary radical source is relatively small. Comparison of top-down estimates of fossil fuel NOx emissions between REAM and GEOS-CHEM shows model dependence. The associated uncertainty is up to 20% on a monthly basis. Averaging over a season reduces this uncertainty. While tropospheric column NO2 decreases over the continent, it increases over the western North Atlantic due to lightning NOx production. Consequently, the REAM model simulates significant increases of tropospheric O-3 over the region as indicated by column data derived from TOMS-SAGE II. Lightning impact is also evident in model-simulated NOx exports.
C1 [Choi, Yunsoo; Wang, Yuhang; Zeng, Tao; Cunnold, Derek; Yang, Eun-Su] Georgia Inst Technol, Sch Earth & Atmospher Sci, Atlanta, GA 30332 USA.
[Martin, Randall] Dalhousie Univ, Dept Phys & Atmospher Sci, Halifax, NS B3H 3J5, Canada.
[Chance, Kelly] Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA.
[Thouret, Valerie] CNRS, Lab Aerol, F-31400 Toulouse, France.
[Edgerton, Eric] Atmospher Res & Anal Inc, Durham, NC 27707 USA.
RP Choi, Y (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM ywang@eas.gatech.edu
RI Wang, Yuhang/B-5578-2014; Chem, GEOS/C-5595-2014;
OI Chance, Kelly/0000-0002-7339-7577
FU NASA Atmospheric Chemistry Modeling and Analysis Program; National
Science Foundation Atmospheric Chemistry Program
FX We thank Daniel Jacob and Robert Yantosca for providing GEOS-CHEM model
and data, Mian Chin for providing aerosol optical depth data, Dale Allen
and Louisa Emmons for helping us analyze MOPITT CO and ozonesonde data,
and Kenneth Cummins for providing the NLDN effective detection
efficiency. The GEOS-CHEM model is managed at Harvard University with
support from the NASA Atmospheric Chemistry Modeling and Analysis
Program. This work was supported by the National Science Foundation
Atmospheric Chemistry Program.
NR 52
TC 30
Z9 31
U1 0
U2 15
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 2169-897X
J9 J GEOPHYS RES-ATMOS
JI J. Geophys. Res.-Atmos.
PD OCT 24
PY 2008
VL 113
IS D20
AR D20311
DI 10.1029/2007JD009632
PG 16
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 365GI
UT WOS:000260393500001
ER
PT J
AU Young, AP
Knysh, S
Smelyanskiy, VN
AF Young, A. P.
Knysh, S.
Smelyanskiy, V. N.
TI Size Dependence of the Minimum Excitation Gap in the Quantum Adiabatic
Algorithm
SO PHYSICAL REVIEW LETTERS
LA English
DT Article
ID PHASE-TRANSITIONS; EVOLUTION
AB We study the typical (median) value of the minimum gap in the quantum version of the exact cover problem using quantum Monte Carlo simulations, in order to understand the complexity of the quantum adiabatic algorithm for much larger sizes than before. For a range of sizes N <= 128, where the classical Davis-Putnam algorithm shows exponential median complexity, the quantum adiabatic algorithm shows polynomial median complexity. The bottleneck of the algorithm is an isolated avoided-crossing point of a Landau-Zener type (collision between the two lowest energy levels only).
C1 [Young, A. P.] Univ Calif Santa Cruz, Dept Phys, Santa Cruz, CA 95064 USA.
[Knysh, S.] NASA, Ames Res Ctr, ELORET Corp, Moffett Field, CA 94035 USA.
RP Young, AP (reprint author), Univ Calif Santa Cruz, Dept Phys, Santa Cruz, CA 95064 USA.
EM peter@physics.ucsc.edu; sergey.i.knysh@nasa.gov;
Vadim.N.Smelyanskiy@nasa.gov
FU NSF [DMR 0337049]; Hierarchical Systems Research Foundation; U.S.
National Security Agency's Laboratory of Physics Sciences; NASA ARC NAS
Supercomputing Center
FX The work of A.P.Y. is supported by NSF Grant No. DMR 0337049 and by a
generous allocation of computer time from the Hierarchical Systems
Research Foundation. The work of S. K. and V.N.S. is supported by U.S.
National Security Agency's Laboratory of Physics Sciences and NASA ARC
NAS Supercomputing Center.
NR 14
TC 69
Z9 70
U1 0
U2 4
PU AMER PHYSICAL SOC
PI COLLEGE PK
PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA
SN 0031-9007
J9 PHYS REV LETT
JI Phys. Rev. Lett.
PD OCT 24
PY 2008
VL 101
IS 17
AR 170503
DI 10.1103/PhysRevLett.101.170503
PG 4
WC Physics, Multidisciplinary
SC Physics
GA 365CN
UT WOS:000260383600010
PM 18999732
ER
PT J
AU Gopalswamy, N
Xie, H
AF Gopalswamy, N.
Xie, H.
TI Comment on "Prediction of the 1-AU arrival times of CME-associated
interplanetary shocks: Evaluation of an empirical interplanetary shock
propagation model" by K.-H. Kim et al.
SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
LA English
DT Editorial Material
ID CORONAL MASS EJECTIONS
C1 [Gopalswamy, N.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
[Xie, H.] Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA.
RP Gopalswamy, N (reprint author), NASA, Goddard Space Flight Ctr, Bldg 21,Room 260,Code 695, Greenbelt, MD 20771 USA.
EM gopals@ssedmail.gsfc.nasa.gov
RI Gopalswamy, Nat/D-3659-2012
NR 13
TC 3
Z9 3
U1 0
U2 1
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0148-0227
J9 J GEOPHYS RES-SPACE
JI J. Geophys. Res-Space Phys.
PD OCT 23
PY 2008
VL 113
IS A10
AR A10105
DI 10.1029/2008JA013030
PG 5
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 365FF
UT WOS:000260390600001
ER
PT J
AU Huttunen, KEJ
Kilpua, SP
Pulkkinen, A
Viljanen, A
Tanskanen, E
AF Huttunen, K. E. J.
Kilpua, S. P.
Pulkkinen, A.
Viljanen, A.
Tanskanen, E.
TI Solar wind drivers of large geomagnetically induced currents during the
solar cycle 23
SO SPACE WEATHER-THE INTERNATIONAL JOURNAL OF RESEARCH AND APPLICATIONS
LA English
DT Article
ID MAGNETOSPHERIC STORMS; MAGNETIC-FIELDS
AB In this paper we investigate the interplanetary drivers of the largest geomagnetically induced currents (GIC) during the solar cycle 23. Interplanetary coronal mass ejections (ICMEs) are the major causes of intense geomagnetic storms and large GIC. In particular, in this work we examine the effectiveness of different structures embedded in an ICME (namely sheath regions, ejecta, and boundary layers) in causing large GIC. It was found that when an ICME interacts with the Earth's magnetosphere the most intense GIC activity is likely to take place during the passage of the turbulent sheath region. The effectiveness of sheath regions in driving large GIC is possibly due to their capability to trigger substorms and to drive intense directly driven ionospheric activity. We also investigated the relationships between different solar wind parameters and the GIC amplitudes. The best correlation with the GIC amplitudes was found with the solar wind electric field and the epsilon parameter. Ejecta-associated GIC seem to require an on-going magnetospheric Dst storm while sheath regions and boundary layers can cause large GIC even when no activity is taking place in terms of Dst. Interestingly, four of the nine ejecta-associated GIC took place during the recovery phases of a intense magnetic storm (but when Dst still was having storm time values below -50 nT).
C1 [Huttunen, K. E. J.; Kilpua, S. P.] Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA.
[Pulkkinen, A.] NASA, Goddard Earth Sci & Technol Ctr, Greenbelt, MD 20771 USA.
[Tanskanen, E.] Univ Bergen, Dept Phys & Technol, N-5007 Bergen, Norway.
[Viljanen, A.] Finnish Meteorol Inst, FIN-00101 Helsinki, Finland.
RP Huttunen, KEJ (reprint author), Univ Calif Berkeley, Space Sci Lab, 7 Gauss Way, Berkeley, CA 94720 USA.
EM huttunen@ssl.berkeley.edu; samik@ssl.berkeley.edu;
antti.a.pulkkinen@nasa.gov; eija.tanskanen@fmi.fi; ari.viljanen@fmi.fi
RI Kilpua, Emilia/G-8994-2012
NR 24
TC 20
Z9 21
U1 0
U2 3
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 1542-7390
J9 SPACE WEATHER
JI Space Weather
PD OCT 23
PY 2008
VL 6
IS 10
AR S10002
DI 10.1029/2007SW000374
PG 8
WC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology &
Atmospheric Sciences
SC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology &
Atmospheric Sciences
GA 365EZ
UT WOS:000260390000001
ER
PT J
AU Rignot, E
Box, JE
Burgess, E
Hanna, E
AF Rignot, E.
Box, J. E.
Burgess, E.
Hanna, E.
TI Mass balance of the Greenland ice sheet from 1958 to 2007
SO GEOPHYSICAL RESEARCH LETTERS
LA English
DT Article
ID ACCELERATION
AB We combine estimates of the surface mass balance, SMB, of the Greenland ice sheet for years 1958 to 2007 with measurements of the temporal variability in ice discharge, D, to deduce the total ice sheet mass balance. During that time period, we find a robust correlation ( R-2 = 0.83) between anomalies in SMB and in D, which we use to reconstruct a continuous series of total ice sheet mass balance. We find that the ice sheet was losing 110 +/- 70 Gt/yr in the 1960s, 30 +/- 50 Gt/yr or near balance in the 1970s - 1980s, and 97 +/- 47 Gt/yr in 1996 increasing rapidly to 267 +/- 38 Gt/yr in 2007. Multi-year variations in ice discharge, themselves related to variations in SMB, cause 60 +/- 20% more variation in total mass balance than SMB, and therefore dominate the ice sheet mass budget. Citation: Rignot, E., J. E. Box, E. Burgess, and E. Hanna ( 2008), Mass balance of the Greenland ice sheet from 1958 to 2007, Geophys. Res. Lett., 35, L20502, doi: 10.1029/2008GL035417.
C1 [Rignot, E.] Univ Calif Irvine, Dept Earth Syst Sci, Irvine, CA 92697 USA.
[Box, J. E.] Ohio State Univ, Byrd Polar Res Ctr, Columbus, OH 43201 USA.
[Burgess, E.] Univ Utah, Dept Geog, Salt Lake City, UT 84112 USA.
[Burgess, E.] Univ Sheffield, Dept Geog, Sheffield S10 2TN, S Yorkshire, England.
[Rignot, E.] CALTECH, Jet Prop Lab, Pasadena, CA USA.
RP Rignot, E (reprint author), Univ Calif Irvine, Dept Earth Syst Sci, Irvine, CA 92697 USA.
EM erignot@uci.edu
RI Rignot, Eric/A-4560-2014; Hanna, Edward/H-2219-2016; Box,
Jason/H-5770-2013
OI Rignot, Eric/0000-0002-3366-0481; Hanna, Edward/0000-0002-8683-182X;
FU NASA [NNG06GB70G, NNX07AM82G]
FX This work was performed at the University of California, Irvine, the
California Institute of Technology's Jet Propulsion Laboratory, the
University of Utah and The Ohio State University under a contract with
the National Aeronautics and Space Administration's Cryospheric Science
Program. EH acknowledges P. Huybrechts and I. Janssens for contribution
of the runoff model used for Hanna SMB estimates. EB was supported by
NASA grant NNG06GB70G. JB was supported by NASA grant NNX07AM82G.
NR 22
TC 191
Z9 193
U1 10
U2 38
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0094-8276
J9 GEOPHYS RES LETT
JI Geophys. Res. Lett.
PD OCT 22
PY 2008
VL 35
IS 20
AR L20502
DI 10.1029/2008GL035417
PG 5
WC Geosciences, Multidisciplinary
SC Geology
GA 365GP
UT WOS:000260394200005
ER
PT J
AU Lokupitiya, RS
Zupanski, D
Denning, AS
Kawa, SR
Gurney, KR
Zupanski, M
AF Lokupitiya, R. S.
Zupanski, D.
Denning, A. S.
Kawa, S. R.
Gurney, K. R.
Zupanski, M.
TI Estimation of global CO2 fluxes at regional scale using the maximum
likelihood ensemble filter
SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
LA English
DT Article
ID DATA ASSIMILATION; ATMOSPHERIC TRANSPORT; KALMAN FILTER; ERROR
ESTIMATION; MODEL; INVERSIONS
AB We use an ensemble-based data assimilation method, known as the maximum likelihood ensemble filter (MLEF), which has been coupled with a global atmospheric transport model to estimate slowly varying biases of carbon surface fluxes. Carbon fluxes for this test consist of hourly gross primary production and ecosystem, respiration over land, and air-sea gas exchange. Persistent multiplicative biases intended to represent incorrectly simulated biogeochemical or land-management processes such as stand age, soil fertility, or coarse woody debris were estimated for 1 year at 10 degrees longitude by 6 degrees latitude spatial resolution and with an 8-week time window. We tested the model using a pseudodata experiment with an existing observation network that includes flasks, aircraft profiles, and continuous measurements. Because of the underconstrained nature of the problem, strong covariance smoothing was applied in the first data assimilation cycle, and localization schemes have been introduced. Error covariance was propagated in subsequent cycles. The coupled model satisfactorily recovered the land biases in densely observed areas. Ocean biases, however, were poorly constrained by the atmospheric observations. Unlike in batch mode inversions, the MLEF has a capability of assimilating large observation vectors and hence is suitable for assimilating hourly continuous observations and satellite observations in the future. Uncertainty was reduced further in our pseudodata experiment than by previous batch methods because of the ability to assimilate a large observation vector. Propagation of spatial covariance and dynamic localization avoid the need for prescribed spatial patterns of error covariance centered at observation sites as in previous grid-scale methods.
C1 [Lokupitiya, R. S.; Denning, A. S.] Colorado State Univ, Dept Atmospher Sci, Ft Collins, CO 80523 USA.
[Gurney, K. R.] Purdue Univ, Dept Earth & Atmospher Sci, W Lafayette, IN 47907 USA.
[Zupanski, D.; Zupanski, M.] Colorado State Univ, Cooperat Inst Res Atmosphere, Ft Collins, CO 80523 USA.
[Kawa, S. R.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
RP Lokupitiya, RS (reprint author), Colorado State Univ, Dept Atmospher Sci, Ft Collins, CO 80523 USA.
EM ravi@atmos.colostate.edu
RI Kawa, Stephan/E-9040-2012; Denning, Scott/F-4974-2011
OI Denning, Scott/0000-0003-3032-7875
FU North American Carbon Program; NASA [NNX06AC75G, NNG05GF41G 02]
FX This research constitutes a part of the North American Carbon Program.
We are thankful to David Baker for providing the low-resolution version
of the PCTM model. We would also like to thank Wouter Peters for his
valuable comments. This research was funded by NASA grants (NNX06AC75G
and NNG05GF41G 02).
NR 39
TC 23
Z9 23
U1 0
U2 7
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 2169-897X
EI 2169-8996
J9 J GEOPHYS RES-ATMOS
JI J. Geophys. Res.-Atmos.
PD OCT 22
PY 2008
VL 113
IS D20
AR D20110
DI 10.1029/2007JD009679
PG 19
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 365GG
UT WOS:000260393300001
ER
PT J
AU Geissler, PE
Johnson, JR
Sullivan, R
Herkenhoff, K
Mittlefehldt, D
Fergason, R
Ming, D
Morris, R
Squyres, S
Soderblom, L
Golombek, M
AF Geissler, P. E.
Johnson, J. R.
Sullivan, R.
Herkenhoff, K.
Mittlefehldt, D.
Fergason, R.
Ming, D.
Morris, R.
Squyres, S.
Soderblom, L.
Golombek, M.
TI First in situ investigation of a dark wind streak on Mars
SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS
LA English
DT Article
ID VARIABLE FEATURES; EOLIAN FEATURES; SEDIMENT; CRATERS; MODEL
AB Prominent low-albedo wind streaks issue from embayments at the north end of Victoria crater in Meridiani Planum, the site of surface investigations by the Mars Exploration Rover Opportunity. Opportunity was sent to examine the darkest of these wind streaks and compare it to the adjacent soil in the brighter corridor between the streaks. Two nearby sites inside and outside of the streak were selected for visible and infrared remote sensing and for elemental abundance measurements and images of the microscopic soil morphology. The rover was next sent to study the interaction of the wind streak with an obstacle, a small rock near the source of the streak. Opportunity's observations suggest that the Victoria wind streaks are deposits of basaltic sand blown out of the crater from the dark dunes nestled below the crater rim, particularly at the base of the alcove leading up to the darkest streak. No local sources of sand have been identified within the Victoria crater wall rock, suggesting that the sand is supplied from outside the crater and is presently escaping its temporary topographic trap. This process presents a possible explanation for the serrated margin of Victoria crater through abrasion of the soft rock as trapped sands are blown out of the crater and carve alcoves under various seasonal winds. Some indication of the rate of activity of these wind streaks will be provided by continued monitoring of the erasure of the rover's tracks.
C1 [Geissler, P. E.; Johnson, J. R.; Herkenhoff, K.; Fergason, R.; Soderblom, L.] US Geol Survey, Flagstaff, AZ 86001 USA.
[Golombek, M.] CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA.
[Mittlefehldt, D.; Ming, D.; Morris, R.] NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA.
[Sullivan, R.; Squyres, S.] Cornell Univ, Dept Astron, Ithaca, NY 14853 USA.
[Fergason, R.] Arizona State Univ, Dept Geol Sci, Tempe, AZ 85287 USA.
RP Geissler, PE (reprint author), US Geol Survey, 2255 N Gemini Dr, Flagstaff, AZ 86001 USA.
EM pgeissler@usgs.gov; jrjohnson@usgs.gov; rjs33@cornell.edu;
kherkenhoff@usgs.gov; David.W.Mittlefehldt@nasa.gov;
Robin.Fergason@asu.edu; Douglas.W.Ming@nasa.gov;
richard.v.morris@nasa.gov; squyres@astrosun.tn.cornell.edu;
lsoderblom@usgs.gov; Matt.Golombek@jpl.nasa.gov
RI Johnson, Jeffrey/F-3972-2015
NR 24
TC 34
Z9 34
U1 0
U2 1
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0148-0227
J9 J GEOPHYS RES-PLANET
JI J. Geophys. Res.-Planets
PD OCT 22
PY 2008
VL 113
IS E12
AR E12S31
DI 10.1029/2008JE003102
PG 16
WC Geochemistry & Geophysics
SC Geochemistry & Geophysics
GA 365FW
UT WOS:000260392300001
ER
PT J
AU Knobelspiesse, KD
Cairns, B
Schmid, B
Roman, MO
Schaaf, CB
AF Knobelspiesse, Kirk D.
Cairns, Brian
Schmid, Beat
Roman, Miguel O.
Schaaf, Crystal B.
TI Surface BRDF estimation from an aircraft compared to MODIS and ground
estimates at the Southern Great Plains site
SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
LA English
DT Article
ID REFLECTANCE DISTRIBUTION FUNCTION; BROAD-BAND CONVERSIONS;
REMOTE-SENSING DATA; BIDIRECTIONAL REFLECTANCE; PLANETARY ATMOSPHERES;
MULTIPLE-SCATTERING; ALBEDO RETRIEVALS; POLARIZED-LIGHT; NARROW-BAND;
VALIDATION
AB Surface albedo, which quantifies the amount of solar radiation reflected by the ground, is an important component of climate models. However, it can be highly heterogeneous, so obtaining adequate measurements are challenging. Global measurements require orbital observations, such as those provided by the Moderate Resolution Imaging Spectroradiometer (MODIS). Satellites estimate the surface bidirectional reflectance distribution function (BRDF), a surface inherent optical property, by correcting observed radiances for atmospheric effects and accumulating measurements at many viewing and solar geometries. The BRDF is then used to estimate albedo, an apparent optical property utilized by climate models. Satellite observations are often validated with ground radiometer measurements. However, spatial and temporal sampling differences mean that direct comparisons are subject to substantial uncertainties. We attempt to bridge the resolution gap using an airborne radiometer, the Research Scanning Polarimeter (RSP). RSP was flown at low altitude in the vicinity of the Department of Energy's Southern Great Plains Central Facility (SGP CF) in Oklahoma during the Aerosol Lidar Validation Experiment (ALIVE) in September, 2005. The RSP's scanning radiometers estimate the BRDF in seconds, rather than days required by MODIS, and utilize the Ames Airborne Tracking Sunphotometer (AATS-14) for atmospheric correction. Our comparison indicates that surface albedo estimates from RSP and MODIS agree with Best Estimate Radiation Flux (BEFLUX) ground radiometer observations at the SGP CF. Since the RSP is an airborne prototype of the Aerosol Polarimetery Sensor (APS), due to be launched into orbit in 2009, these techniques could form the basis for routine BRDF validation.
C1 [Knobelspiesse, Kirk D.; Cairns, Brian] Columbia Univ, Dept Appl Phys & Appl Math, New York, NY 10025 USA.
[Cairns, Brian] NASA, Goddard Inst Space Studies, New York, NY 10025 USA.
[Schmid, Beat] Pacific NW Natl Lab, Atmospher Sci & Global Change Div, Richland, WA 99352 USA.
[Roman, Miguel O.; Schaaf, Crystal B.] Boston Univ, Ctr Remote Sensing, Dept Geog & Environm, Boston, MA 02215 USA.
RP Knobelspiesse, KD (reprint author), Columbia Univ, Dept Appl Phys & Appl Math, 2880 Broadway, New York, NY 10025 USA.
EM kdk2103@columbia.edu
RI Roman, Miguel/D-4764-2012; Knobelspiesse, Kirk/S-5902-2016;
OI Roman, Miguel/0000-0003-3953-319X; Knobelspiesse,
Kirk/0000-0001-5986-1751; Cairns, Brian/0000-0002-1980-1022
FU US National Science Foundation; U. S. Department of Energy, Office of
Science, Office of Biological and Environmental Research, Environmental
Sciences Division; ARM; National Aeronautics and Space Administration
(NASA)
FX The first author acknowledges support from the US National Science
Foundation, through a Fellowship in the IGERT Joint Program in Applied
Mathematics and Earth and Environmental Science at Columbia University
at the time of the ALIVE field campaign. BEFLUX data were obtained from
the Atmospheric Radiation Measurement (ARM) Program sponsored by the U.
S. Department of Energy, Office of Science, Office of Biological and
Environmental Research, Environmental Sciences Division. ALIVE was also
funded by ARM, and RSP participation during that experiment was funded
by the National Aeronautics and Space Administration (NASA). Thanks to
the many who helped collect the data used in this study: Ben Hovelman
was the J-31 pilot, Roy Johnson and Nicholas Truong were AATS-14
engineers, Rose Dominguez provided J-31 Navigational and GPS data, and
Warren Gore provided J-31 Meteorological data. Finally, thanks to both
the anonymous reviewers.
NR 49
TC 23
Z9 28
U1 1
U2 7
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 2169-897X
J9 J GEOPHYS RES-ATMOS
JI J. Geophys. Res.-Atmos.
PD OCT 21
PY 2008
VL 113
IS D20
AR D20105
DI 10.1029/2008JD010062
PG 21
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 365GE
UT WOS:000260393100007
ER
PT J
AU Yang, ES
Cunnold, DM
Newchurch, MJ
Salawitch, RJ
McCormick, MP
Russell, JM
Zawodny, JM
Oltmans, SJ
AF Yang, E. -S.
Cunnold, D. M.
Newchurch, M. J.
Salawitch, R. J.
McCormick, M. P.
Russell, J. M., III
Zawodny, J. M.
Oltmans, S. J.
TI First stage of Antarctic ozone recovery
SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
LA English
DT Article
ID STRATOSPHERIC POLAR VORTEX; MCMURDO STATION; SOUTH-POLE; DEPLETION;
TRANSPORT; IMPACT; HOLE; AIR
AB Ozone within the springtime Antarctic vortex is affected by both chemical and dynamical processes. We use correlations between monthly means of total ozone columns and temperatures in the vortex core and the vortex edge (or collar) regions to construct ozone anomaly time series for September and October, which mainly reflect variations in ozone due to chemical forcing. The ozone anomaly time series, obtained from ground-based Dobson/Brewer column measurements, reveal a statistically significant leveling off of total ozone, relative to the previous rate of decline, since 1997. The second derivative with respect to time of stratospheric halogen loading in the Antarctic vortex reached a well-defined minimum in 1997, marking the time when the chemical forcing of polar ozone loss started leveling off. Vertical profiles of ozone in the Antarctic vortex from SAGE II and ozonesondes show that near-zero levels of ozone have sometimes been reached in the core of the vortex each October, between the 380 and 500 K isentropes, since 1992. We have accounted for this so-called loss saturation effect in our analysis by comparing the frequency distribution of measured ozone with the distribution expected from a reconstruction of ozone that hypothetically allows ozone abundances to drop below zero. This approach indicates that changes in stratospheric halogen loading, not the loss saturation effect, are the primary cause of the recent leveling off of the total ozone anomaly time series. This analysis indicates that total column ozone within the Antarctic vortex core and collar regions has reached the first stage of recovery as defined by the World Meteorological Organization: a statistically significant reduction in the rate of decline that is clearly attributable to decreases in the abundance of ozone-depleting substances brought about by the Montreal Protocol.
C1 [Yang, E. -S.; Cunnold, D. M.] Georgia Inst Technol, Sch Earth & Atmospher Sci, Atlanta, GA 30332 USA.
[McCormick, M. P.; Russell, J. M., III] Hampton Univ, Ctr Atmospher Sci, Hampton, VA 23668 USA.
[Newchurch, M. J.] Univ Alabama, Dept Atmospher Sci, Huntsville, AL 35805 USA.
[Oltmans, S. J.] NOAA, Earth Syst Res Lab, Boulder, CO 80305 USA.
[Zawodny, J. M.] NASA, Langley Res Ctr, Hampton, VA 23681 USA.
[Salawitch, R. J.] CALTECH, Jet Prop Lab, Pasadena, CA USA.
RP Yang, ES (reprint author), Georgia Inst Technol, Sch Earth & Atmospher Sci, 311 Ferst Dr, Atlanta, GA 30332 USA.
EM mike@nsstc.uah.edu
RI Salawitch, Ross/B-4605-2009
OI Salawitch, Ross/0000-0001-8597-5832
FU NASA at Georgia Tech
FX We thank P. Newman for providing a Web site that we have used to
calculate EEASC and for many helpful discussions. Dobson/ Brewer total
ozone and ozonesonde ozone data were provided by the Swiss
Meteorological Service with additional data available at the World Ozone
and Ultraviolet Data Center (WOUDC). Dobson total ozone data at
Vernadsky (Faraday) and Halley were obtained from the British Antarctic
Survey (BAS). Ozonesonde data at South Pole were provided by NOAA/ESRL.
The NCEP temperature data were obtained from NOAA-CIRES/CDC. E.-S. Yang
was supported by NASA at Georgia Tech for the majority of this work.
NASA also provided the majority of support to the other authors for this
research. Work at the Jet Propulsion Laboratory, California Institute of
Technology, was performed under contract with the National Aeronautics
and Space Administration. We thank three anonymous reviewers for
providing many detailed, thoughtful comments that led to substantial
revisions and a significantly improved paper. We note that our paper
represents the complete data record from the remarkable SAGE and HALOE
instruments. SAGE I commenced observations in 1979 and SAGE II ceased
operating on 22 August 2005. HALOE ceased operating on 14 December 2005.
The SAGE I/II and HALOE instruments documented the relationship between
CFCs and polar ozone depletion, details of the microphysics of polar
stratospheric cloud formation, and the physical (denitrification) and
chemical (chlorine activation) effect of PSCs. The data record provided
by these instruments played an important role in quantifying the effect
of human activity on the polar ozone depletion that led to the passage
of the Montreal Protocol and its amendments, which have essentially
eliminated the production of CFCs and related species. It is a strong
testament to the respective instrument teams that both SAGE II and HALOE
remained operational long enough to observe the beginning of the
recovery of the Antarctic ozone hole.
NR 39
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U1 2
U2 10
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 2169-897X
J9 J GEOPHYS RES-ATMOS
JI J. Geophys. Res.-Atmos.
PD OCT 21
PY 2008
VL 113
IS D20
AR D20308
DI 10.1029/2007JD009675
PG 16
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 365GE
UT WOS:000260393100001
ER
PT J
AU Leblanc, T
McDermid, IS
AF Leblanc, Thierry
McDermid, I. Stuart
TI Accuracy of Raman lidar water vapor calibration and its applicability to
long-term measurements
SO APPLIED OPTICS
LA English
DT Article
ID HUMIDITY MEASUREMENTS
AB A Raman lidar calibration method adapted to the long-term monitoring of atmospheric water vapor is proposed. The accuracy of Raman lidar water vapor profiles is limited by that of the calibration process. Typically, calibration using in situ balloon-borne measurements suffers from the nonsimultaneity and noncollocation of the lidar and in situ measurements, while calibration from passive remote sensors suffers from the lower accuracy of the retrievals and incomplete sampling of the water vapor column observed by lidar. We propose a new hybrid calibration method using a combination of absolute calibration from radiosonde campaigns and routine-basis (off-campaign) partial calibration using a standard lamp. This new method takes advantage of the stability of traceable calibrated lamps as reliable sources of known spectral irradiance combined with the best available in situ measurements. An integrated approach is formulated, which can be used for the future long-term monitoring of water vapor by Raman lidars within the international Network for the Detection of Atmospheric Composition Change and other networks. (C) 2008 Optical Society of America
C1 [Leblanc, Thierry; McDermid, I. Stuart] CALTECH, Jet Prop Lab, Wrightwood, CA 92397 USA.
RP Leblanc, T (reprint author), CALTECH, Jet Prop Lab, Wrightwood, CA 92397 USA.
EM leblanc@tmf.jpl.nasa.gov
NR 20
TC 25
Z9 25
U1 0
U2 1
PU OPTICAL SOC AMER
PI WASHINGTON
PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA
SN 1559-128X
EI 2155-3165
J9 APPL OPTICS
JI Appl. Optics
PD OCT 20
PY 2008
VL 47
IS 30
BP 5592
EP 5603
DI 10.1364/AO.47.005592
PG 12
WC Optics
SC Optics
GA 369XA
UT WOS:000260726000006
PM 18936807
ER
PT J
AU Li, JV
Hill, CJ
Mumolo, J
Gunapala, S
Mou, S
Chuang, SL
AF Li, Jian V.
Hill, Cory J.
Mumolo, Jason
Gunapala, Sarath
Mou, Shin
Chuang, Shun-Lien
TI Midinfrared type-II InAs/GaSb superlattice photodiodes toward room
temperature operation
SO APPLIED PHYSICS LETTERS
LA English
DT Article
ID ELECTRONS
AB We study midinfrared type-II InAs/GaSb superlattice p-i-n photodiodes for high temperature operation. Representative samples exhibit a 3.9 mu m cutoff wavelength at 250 K and detectivity of 4.9x10(13), 1.0x10(10), and 2.4x10(9) cm Hz(1/2)/W at 78, 240, and 300 K, respectively. Longer-wavelength devices exhibit a 5.2 mu m cutoff wavelength at 240 K, and detectivity of 1.3x10(13) and 1.5x10(9) cm Hz(1/2)/W at 78 and 240 K, respectively. The electron beam induced current technique is used to investigate the spatially varying carrier collection efficiency contribution to the quantum efficiency at different biases and temperatures. The residual doping in the i region is determined to be 6.0x10(13) cm(-3) (n type) at 78 K. The prospect of operating focal plane arrays based on the sample studied around 240 K is quite promising. (C) 2008 American Institute of Physics. [DOI: 10.1063/1.2949744]
C1 [Li, Jian V.; Hill, Cory J.; Mumolo, Jason; Gunapala, Sarath] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[Mou, Shin; Chuang, Shun-Lien] Univ Illinois, Dept Elect & Comp Engn, Urbana, IL 61801 USA.
RP Li, JV (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM cory.j.hill@jpl.nasa.gov
RI Li, Jian/B-1627-2016
NR 12
TC 34
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U1 2
U2 10
PU AMER INST PHYSICS
PI MELVILLE
PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1,
MELVILLE, NY 11747-4501 USA
SN 0003-6951
J9 APPL PHYS LETT
JI Appl. Phys. Lett.
PD OCT 20
PY 2008
VL 93
IS 16
AR 163505
DI 10.1063/1.2949744
PG 3
WC Physics, Applied
SC Physics
GA 365CO
UT WOS:000260383700078
ER
PT J
AU Zheng, W
Wang, JX
Kriss, GA
Sahnow, D
Allen, M
Dopita, M
Tsvetanov, Z
Bicknell, G
AF Zheng, Wei
Wang, Jun-Xian
Kriss, Gerard A.
Sahnow, David
Allen, Mark
Dopita, Michael
Tsvetanov, Zlatan
Bicknell, Geoffrey
TI SPATIALLY RESOLVED FAR-ULTRAVIOLET SPECTROSCOPY OF THE NUCLEAR REGION OF
NGC 1068
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE galaxies: active; galaxies: individual (NGC 1068); galaxies: Seyfert
ID NARROW-LINE REGION; ACTIVE GALAXIES; PHYSICAL CONDITIONS;
SEYFERT-GALAXIES; IONIZED-GAS; FAST SHOCKS; RADIO JETS; X-RAY; NGC-1068;
EMISSION
AB We carry out high-resolution FUSE spectroscopy of the nuclear region of NGC 1068. The first set of spectra was obtainedwith a 3000 square aperture that collected all emission from the narrow-line region. The data reveal a strong broad O VI component of FWHM similar to 3500 km s(-1) and two narrow O VI lambda lambda 1031, 1037 components of similar to 350 km s(-1). The C III lambda 977 and N III lambda 991 emission lines in this spectrum can be fitted with a narrow component of FWHM similar to 1000 km s(-1) and a broad one of similar to 2500 km s(-1). Another set of seven spatially resolved spectra was made using a long slit of 1.25" x 20" at steps of similar to 1" along the axis of the emission-line cone. We find the following: (1) Major emission lines in the FUSE wavelength range consist of a broad and a narrow component. (2) There is a gradient in the velocity field for the narrow O VI component of similar to 200 km s(-1) from similar to 2" southwest of the nucleus to similar to 4" northeast. A similar pattern is also observed with the broad O VI component, with a gradient of similar to 3000 km s(-1). These are consistent with the HST STIS findings and suggest a biconical structure in which the velocity field is mainly radial outflow. (3) A major portion of the C III and N III line flux is produced in the compact core. They are therefore not effective temperature diagnostics for the conical region. (4) The best-fit UV continuum suggests virtually no reddening, and the He II I(lambda 1640)/I(lambda 1085) ratio suggests a consistently low extinction factor across the cone. At similar to 2" northeast of the nucleus there is a region characterized by (a) a strong Ly alpha flux but normal C IV flux, (b) a broad O VI line, and (c) a significantly enhanced C III flux.
C1 [Zheng, Wei; Wang, Jun-Xian; Kriss, Gerard A.; Sahnow, David; Tsvetanov, Zlatan] Johns Hopkins Univ, Dept Phys & Astron, Ctr Astrophys Sci, Baltimore, MD 21218 USA.
[Wang, Jun-Xian] Univ Sci & Technol China, Ctr Astrophys, Hefei 230026, Anhui, Peoples R China.
[Kriss, Gerard A.] Space Telescope Sci Inst, Baltimore, MD 21218 USA.
[Allen, Mark] Observ Strasbourg, F-67000 Strasbourg, France.
[Dopita, Michael; Bicknell, Geoffrey] Australian Natl Univ, Mt Stromlo & Siding Spring Observ, Weston, ACT 2611, Australia.
[Tsvetanov, Zlatan] NASA Headquarters, Washington, DC 20546 USA.
RP Zheng, W (reprint author), Johns Hopkins Univ, Dept Phys & Astron, Ctr Astrophys Sci, Baltimore, MD 21218 USA.
OI Allen, Mark/0000-0003-2168-0087; Dopita, Michael/0000-0003-0922-4986
FU NASA [NAG-8-1527, NAG-8-1133]
FX W. Z. would like to thank the FUSE team, particularly W. Blair, for
their painstaking help in planning the observations of NGC 1068 and
postobservation studies of engineering data. This work has been
supported in part by NASA grants NAG-8-1527 and NAG-8-1133. The FUSE and
HST data presented in this paper were obtained from the Multimission
Archive at the Space Telescope Science Institute (MAST).
NR 36
TC 2
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U1 0
U2 2
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD OCT 20
PY 2008
VL 686
IS 2
BP 881
EP 891
DI 10.1086/591547
PG 11
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 364YB
UT WOS:000260370500011
ER
PT J
AU Krick, JE
Surace, JA
Thompson, D
Ashby, MLN
Hora, JL
Gorjian, V
Yan, L
AF Krick, J. E.
Surace, J. A.
Thompson, D.
Ashby, M. L. N.
Hora, J. L.
Gorjian, V.
Yan, L.
TI GALAXY CLUSTERS IN THE IRAC DARK FIELD. I. GROWTH OF THE RED SEQUENCE
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE cosmology: observations; galaxies: clusters: general; galaxies:
evolution; galaxies: photometry
ID COLOR-MAGNITUDE RELATION; RAY SCALING RELATIONS; ROSAT POINTED SURVEY;
LUMINOSITY FUNCTION; HIGH-REDSHIFT; EVOLUTION; POPULATION; DISCOVERY;
MASS; RDCS-1252.9-2927
AB Using three newly identified galaxy clusters at z similar to 1 (photometric redshift) we measure the evolution of the galaxies within clusters from high redshift to the present day by studying the growth of the red cluster sequence. The clusters are located in the Spitzer InfraredArray Camera (IRAC) Dark Field, an extremely deep mid-infrared survey near the north ecliptic pole with photometry in 18 total bands from X-ray through far-IR. Two of the candidate clusters are additionally detected as extended emission in matching Chandra data in the survey area, allowing us to measure their masses to be M-500 = (6.2 +/- 1.0) x 10(13) and (3.6 +/- 1.1) x 10(13) M-circle dot. For all three clusters we create a composite color-magnitude diagram in rest-frame B - K using our deep HST and Spitzer imaging. By comparing the fraction of low-luminosity member galaxies on the composite red sequence with the corresponding population in local clusters at z 0: 1 taken from COSMOS, we examine the effect of a galaxy's mass on its evolution. We find a deficit of faint galaxies on the red sequence in our z similar to 1 clusters, which implies that more massive galaxies have evolved in clusters faster than less massive galaxies, and that the lessmassive galaxies are still forming stars in clusters such that they have not yet settled onto the red sequence.
C1 [Krick, J. E.; Surace, J. A.; Yan, L.] CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA.
[Thompson, D.] Univ Arizona, Large Binocular Telescope Observ, Tucson, AZ 85721 USA.
[Ashby, M. L. N.; Hora, J. L.] Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA.
[Gorjian, V.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Krick, JE (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91125 USA.
OI Hora, Joseph/0000-0002-5599-4650
NR 44
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U1 0
U2 2
PU IOP PUBLISHING LTD
PI BRISTOL
PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND
SN 0004-637X
EI 1538-4357
J9 ASTROPHYS J
JI Astrophys. J.
PD OCT 20
PY 2008
VL 686
IS 2
BP 918
EP 926
DI 10.1086/591788
PG 9
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 364YB
UT WOS:000260370500014
ER
PT J
AU Stothers, RB
AF Stothers, Richard B.
TI ANALYTIC CRITERIA FOR THE MECHANICAL AND THERMAL STABILITY OF MAGNETIC
STARS WITH FINITE ELECTRICAL CONDUCTIVITY
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE instabilities; MHD; stars: magnetic fields; stars: oscillations; stars:
variables: other
ID LUMINOUS STELLAR ENVELOPES; FIELDS; CONVECTION; MODELS
AB The usual assumption of infinite electrical conductivity has been relaxed in a new analytic treatment of the magnetohydrodynamics of a variable magnetic star in the simple one-zone approximation. For a not too low electrical conductivity, the magnetic pressure changes with the mass density as roughly rho(4/3), and the Joule heating rate goes as roughly rho. The magnetic effective adiabatic exponent of about 4/3 proves to have only a small influence on the criteria for dynamical, secular, and pulsational stability, but the Joule heating rate directly affects the secular and pulsational stability criteria. Thus, a finite electrical conductivity tends to stabilize a magnetic star secularly and to destabilize it pulsationally. These specific results apply, however, only to purely radial perturbations of the star's upper radiative layers.
C1 NASA, Goddard Inst Space Studies, New York, NY 10025 USA.
RP Stothers, RB (reprint author), NASA, Goddard Inst Space Studies, 2880 Broadway, New York, NY 10025 USA.
NR 36
TC 0
Z9 0
U1 0
U2 2
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD OCT 20
PY 2008
VL 686
IS 2
BP 1275
EP 1279
DI 10.1086/591546
PG 5
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 364YB
UT WOS:000260370500039
ER
PT J
AU Menut, JL
Valat, B
Lopez, B
Schmider, FX
Vakili, F
Jankov, S
Bresson, Y
Lagarde, S
Petrov, RG
Domiciano, A
Mosoni, L
Danchi, WC
AF Menut, J. -L.
Valat, B.
Lopez, B.
Schmider, F. -X.
Vakili, F.
Jankov, S.
Bresson, Y.
Lagarde, S.
Petrov, R. G.
Domiciano, A.
Mosoni, L.
Danchi, W. C.
TI AN ALTERNATIVE APPROACH FOR IMAGING IN OPTICAL INTERFEROMETRY
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE techniques: image processing; techniques: interferometric
ID IOTA-INTERFEROMETER; CAPELLA
AB We describe a mathematical formalism for the teaching optical interferometer concept developed by P. Lawson. In this experiment, the co-addition of several interferometric fringe patterns obtained for different baselines between individual telescopes is the image of the source, for the simple reason that the fringe patterns build up the image of the observed source through a convolution product. This basic principle is of interest since it allows one to tackle the image reconstruction for optical long-baseline interferometry through an approach which is complementary to the use of the Fourier plane. Thus, image reconstruction can be thought of in the fringe plane. It allows a better understanding of the fundamental limits of the image dynamical range.
C1 [Menut, J. -L.; Lopez, B.; Lagarde, S.] Observ Cote Azur, F-06304 Nice 4, France.
[Valat, B.; Schmider, F. -X.; Vakili, F.; Jankov, S.; Petrov, R. G.; Domiciano, A.] Univ Nice Sophia Antipolis, Lab Fizeau, F-06108 Nice, France.
[Mosoni, L.] Max Planck Inst Astron, D-69117 Heidelberg, Germany.
[Mosoni, L.] Hungarian Acad Sci, Konkoly Observ Budapest, H-1525 Budapest, Hungary.
[Danchi, W. C.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
RP Menut, JL (reprint author), Observ Cote Azur, Blvd Observ,BP 4229, F-06304 Nice 4, France.
RI Schmider, Francois-Xavier/C-5435-2012
NR 12
TC 2
Z9 2
U1 0
U2 2
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD OCT 20
PY 2008
VL 686
IS 2
BP 1514
EP 1522
DI 10.1086/590418
PG 9
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 364YB
UT WOS:000260370500062
ER
PT J
AU Bonamente, M
Swartz, DA
Weisskopf, MC
Murray, SS
AF Bonamente, Massimiliano
Swartz, Douglas A.
Weisskopf, Martin C.
Murray, Stephen S.
TI SWIFT XRT OBSERVATIONS OF THE POSSIBLE DARK GALAXY VIRGOHI 21
SO ASTROPHYSICAL JOURNAL LETTERS
LA English
DT Article
DE dark matter; galaxies: individual (VIRGOHI 21); X-rays: galaxies
ID X-RAY-EMISSION; LUMINOSITY FUNCTION; CLUSTER; GAS; NGC-4254; CATALOG;
HALOES; CLOUDS; HI
AB Swift XRT observations of the H (I) line source VIRGOHI 21 were performed on 2008 April 22 and 26 for a total exposure time of 9.2 ks. This is the first pointed X-ray observation of VIRGOHI 21, a putative dark galaxy in the Virgo Cluster, and no photons were detected from this source. The nondetection of extended X-ray emission within the angular extent of the H (I) source corresponds to a 99% confidence upper limit of 2.1 x 10(-14) ergs cm(-2) s(-1) in the 0.3-2.0 keV band. The equivalent upper limit to the amount of diffuse hot gas associated with VIRGOHI 21 is in the range 4 x 10(7)-2 x 10(8) M(circle dot) for a hot gas temperature between 0.1 and 1 keV. The nondetection also corresponds to a 99% confidence upper limit on the flux from a pointlike source of 8 x 10(-15) ergs cm(-2) s(-1) in the 0.3-2.0 keV band. We discuss the constraints on the nature of VIRGOHI 21 imposed by these observations and the theoretical implications of these results.
C1 [Bonamente, Massimiliano] Univ Alabama, Dept Phys, Huntsville, AL 35899 USA.
[Swartz, Douglas A.] NASA, George C Marshall Space Flight Ctr, Univ Space Res Assoc, Huntsville, AL 35812 USA.
[Murray, Stephen S.] Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA.
RP Bonamente, M (reprint author), Univ Alabama, Dept Phys, Huntsville, AL 35899 USA.
NR 28
TC 0
Z9 0
U1 0
U2 0
PU IOP PUBLISHING LTD
PI BRISTOL
PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND
J9 ASTROPHYS J LETT
JI Astrophys. J. Lett.
PD OCT 20
PY 2008
VL 686
IS 2
BP L71
EP L74
DI 10.1086/592819
PG 4
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 398KR
UT WOS:000262731500006
ER
PT J
AU Kashlinsky, A
Atrio-Barandela, F
Kocevski, D
Ebeling, H
AF Kashlinsky, A.
Atrio-Barandela, F.
Kocevski, D.
Ebeling, H.
TI A MEASUREMENT OF LARGE-SCALE PECULIAR VELOCITIES OF CLUSTERS OF
GALAXIES: RESULTS AND COSMOLOGICAL IMPLICATIONS
SO ASTROPHYSICAL JOURNAL LETTERS
LA English
DT Article
DE cosmic microwave background; cosmology: observations; early universe;
large-scale structure of universe
ID X-RAY SEARCH; MACH NUMBER; BULK FLOWS; MILKY-WAY; UNIVERSE; ANISOTROPY;
SAMPLE; DENSITY; PROFILE
AB Peculiar velocities of clusters of galaxies can be measured by studying the fluctuations in the cosmic microwave background (CMB) generated by the scattering of the microwave photons by the hot X-ray-emitting gas inside clusters. While for individual clusters such measurements result in large errors, a large statistical sample of clusters allows one to study cumulative quantities dominated by the overall bulk flow of the sample with the statistical errors integrating down. We present results from such a measurement using the largest all-sky X-ray cluster catalog combined to date and the 3 yr WMAP CMB data. We find a strong and coherent bulk flow on scales out to at least greater than or similar to 300 h(-1) Mpc, the limit of our catalog. This flow is difficult to explain by gravitational evolution within the framework of the concordance Lambda CDM model and may be indicative of the tilt exerted across the entire current horizon by far-away pre-inflationary inhomogeneities.
C1 [Kashlinsky, A.] NASA, Goddard Space Flight Ctr, SSAI, Greenbelt, MD 20771 USA.
[Kashlinsky, A.] NASA, Goddard Space Flight Ctr, Observat Cosmol Lab, Greenbelt, MD 20771 USA.
[Atrio-Barandela, F.] Univ Salamanca, E-37008 Salamanca, Spain.
[Kocevski, D.] Univ Calif Davis, Dept Phys, Davis, CA 95616 USA.
[Ebeling, H.] Univ Hawaii, Inst Astron, Honolulu, HI 96822 USA.
RP Kashlinsky, A (reprint author), NASA, Goddard Space Flight Ctr, SSAI, Code 665, Greenbelt, MD 20771 USA.
EM alexander.kashlinsky@nasa.gov
RI Atrio-Barandela, Fernando/A-7379-2017
OI Atrio-Barandela, Fernando/0000-0002-2130-2513
FU NASA [NNG04G089G]; Ministerio de Educacion y Ciencia/"Junta de Castilla
y Leon" in Spain [FIS2006-05319, PR2005-0359, SA010C05]
FX This work is supported by NASA ADP grant NNG04G089G and the Ministerio
de Educacion y Ciencia/"Junta de Castilla y Leon" in Spain
(FIS2006-05319, PR2005-0359, and SA010C05). We thank Gary Hinshaw for
useful information on the WMAP data specifics.
NR 25
TC 115
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U1 1
U2 4
PU IOP PUBLISHING LTD
PI BRISTOL
PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND
J9 ASTROPHYS J LETT
JI Astrophys. J. Lett.
PD OCT 20
PY 2008
VL 686
IS 2
BP L49
EP L52
DI 10.1086/592947
PG 4
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 398KR
UT WOS:000262731500001
ER
PT J
AU Ng, CK
Reames, DV
AF Ng, C. K.
Reames, D. V.
TI SHOCK ACCELERATION OF SOLAR ENERGETIC PROTONS: THE FIRST 10 MINUTES
SO ASTROPHYSICAL JOURNAL LETTERS
LA English
DT Article
DE acceleration of particles; shock waves; Sun: coronal mass ejections
(CMEs); Sun: particle emission
ID HYDROMAGNETIC WAVE EXCITATION; INTERPLANETARY TRAVELING SHOCKS; EARTHS
BOW SHOCK; PARTICLE-ACCELERATION; ION-ACCELERATION; EVENTS; MODEL;
SIMULATIONS; TURBULENCE; ENERGIES
AB Proton acceleration at a parallel coronal shock is modeled with self-consistent Alfven wave excitation and shock transmission. 18-50 keV seed protons at 0.1% of plasma proton density are accelerated in 10 minutes to a power-law intensity spectrum rolling over at 300 MeV by a 2500 km s(-1) shock traveling outward from 3.5, for typical coronal conditions and low ambient wave intensities. Interaction of high-energy protons of large r(circle dot), pitch angles with Alfven waves amplified by low-energy protons of small pitch angles is key to rapid acceleration. Shock acceleration is not significantly retarded by sunward streaming protons interacting with downstream waves. There is no significant second-order Fermi acceleration.
C1 [Ng, C. K.; Reames, D. V.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
RP Ng, CK (reprint author), Univ Maryland, College Pk, MD 20742 USA.
EM Chee.Ng@nasa.gov; Donald.V.Reames@nasa.gov
FU NASA [LWS-04-0000-0076, SHP040016-0024]
FX We thank the referee for helpful comments. This work was supported by
NASA under LWS-04-0000-0076 and SHP040016-0024.
NR 30
TC 46
Z9 46
U1 0
U2 0
PU IOP PUBLISHING LTD
PI BRISTOL
PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND
J9 ASTROPHYS J LETT
JI Astrophys. J. Lett.
PD OCT 20
PY 2008
VL 686
IS 2
BP L123
EP L126
DI 10.1086/592996
PG 4
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 398KR
UT WOS:000262731500019
ER
PT J
AU Durand, M
Andreadis, KM
Alsdorf, DE
Lettenmaier, DP
Moller, D
Wilson, M
AF Durand, Michael
Andreadis, Konstantinos M.
Alsdorf, Douglas E.
Lettenmaier, Dennis P.
Moller, Delwyn
Wilson, Matthew
TI Estimation of bathymetric depth and slope from data assimilation of
swath altimetry into a hydrodynamic model
SO GEOPHYSICAL RESEARCH LETTERS
LA English
DT Article
ID WATER; RECOVERY
AB The proposed Surface Water and Ocean Topography (SWOT) mission would provide measurements of water surface elevation (WSE) for characterization of storage change and discharge. River channel bathymetry is a significant source of uncertainty in estimating discharge from WSE measurements, however. In this paper, we demonstrate an ensemble-based data assimilation (DA) methodology for estimating bathymetric depth and slope from WSE measurements and the LISFLOOD-FP hydrodynamic model. We performed two proof-of-concept experiments using synthetically generated SWOT measurements. The experiments demonstrated that bathymetric depth and slope can be estimated to within 3.0 microradians or 50 cm, respectively, using SWOT WSE measurements, within the context of our DA and modeling framework. We found that channel bathymetry estimation accuracy is relatively insensitive to SWOT measurement error, because uncertainty in LISFLOOD-FP inputs (such as channel roughness and upstream boundary conditions) is likely to be of greater magnitude than measurement error. Citation: Durand, M., K. M. Andreadis, D. E. Alsdorf, D. P. Lettenmaier, D. Moller, and M. Wilson (2008), Estimation of bathymetric depth and slope from data assimilation of swath altimetry into a hydrodynamic model, Geophys. Res. Lett., 35, L20401, doi: 10.1029/2008GL034150.
C1 [Durand, Michael; Alsdorf, Douglas E.] Ohio State Univ, Byrd Polar Res Ctr, Columbus, OH 43210 USA.
[Andreadis, Konstantinos M.; Lettenmaier, Dennis P.] Univ Washington, Dept Civil & Environm Engn, Seattle, WA 98195 USA.
[Alsdorf, Douglas E.] Ohio State Univ, Dept Earth Sci, Columbus, OH 43210 USA.
[Moller, Delwyn] NASA, Jet Prop Lab, Pasadena, CA 91109 USA.
[Wilson, Matthew] Univ W Indies, Fac Sci & Agr, St Augustine, Trinid & Tobago.
RP Durand, M (reprint author), Ohio State Univ, Byrd Polar Res Ctr, 135 Scott Hall,109 Carmack Rd, Columbus, OH 43210 USA.
EM durand.8@osu.edu; matthew.wilson@sta.uwi.edu
RI Durand, Michael/D-2885-2013; lettenmaier, dennis/F-8780-2011;
OI lettenmaier, dennis/0000-0003-3317-1327; Wilson,
Matthew/0000-0001-9459-6981
FU NASA; Ohio State University
FX This work was funded by NASA's Terrestrial Hydrology Program, and by The
Ohio State University Climate Water Carbon program
(http://bprc.osu.edu/dev/cwc/). We gratefully acknowledge Paul Bates for
use of the LISFLOOD-FP model, the computing resources provided by the
Ohio Supercomputer Center (OSC; www.osc.edu), and Judy Gardiner of the
OSC for help in parallelizing LISFLOOD-FP. Ernesto Rodriguez and two
anonymous reviewers provided valuable input that improved the quality of
the manuscript.
NR 21
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U1 1
U2 18
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0094-8276
EI 1944-8007
J9 GEOPHYS RES LETT
JI Geophys. Res. Lett.
PD OCT 17
PY 2008
VL 35
IS 20
AR L20401
DI 10.1029/2008GL034150
PG 5
WC Geosciences, Multidisciplinary
SC Geology
GA 362DA
UT WOS:000260177200001
ER
PT J
AU Jeong, MJ
Tsay, SC
Ji, Q
Hsu, NC
Hansell, RA
Lee, J
AF Jeong, Myeong-Jae
Tsay, Si-Chee
Ji, Qiang
Hsu, N. Christina
Hansell, Richard A.
Lee, Joonsuk
TI Ground-based measurements of airborne Saharan dust in marine environment
during the NAMMA field experiment
SO GEOPHYSICAL RESEARCH LETTERS
LA English
DT Article
ID RADIATIVE PROPERTIES; OPTICAL-PROPERTIES; AEROSOL; MODEL; THICKNESS
AB Several episodes of airborne mineral dust transported from the Saharan deserts were observed at Sal Island, Cape Verde for 2 - 28 September 2006 during the NASA African Monsoon Multidisciplinary Analyses ( NAMMA) field experiment. Dust particles were mixed with marine background aerosols when the dust layers descended into the marine boundary layer. A new method is developed to derive the optical properties of dust when mixed with maritime aerosols. The derived single scattering albedo and mass scattering efficiency differed significantly between two selected cases leading to differences in their direct radiative effects. Back-trajectory analyses suggest that the two cases were influenced by dust particles originating from different source regions over North Africa. This stresses the importance of resolving dust optical properties in sub-regional scales to attain a better assessment of the role of airborne dust on the climate system. Citation: Jeong, M.-J., S.-C. Tsay, Q. Ji, N. C. Hsu, R. A. Hansell, and J. Lee ( 2008), Ground-based measurements of airborne Saharan dust in marine environment during the NAMMA field experiment, Geophys. Res. Lett., 35, L20805, doi: 10.1029/2008GL035587.
C1 [Jeong, Myeong-Jae] Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21228 USA.
[Jeong, Myeong-Jae; Tsay, Si-Chee; Ji, Qiang; Hsu, N. Christina; Hansell, Richard A.; Lee, Joonsuk] NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA.
[Ji, Qiang; Hansell, Richard A.; Lee, Joonsuk] Univ Maryland, Earth Syst Sci Interdisciplinary Ctr, College Pk, MD 20742 USA.
RP Jeong, MJ (reprint author), Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, 5523 Res Pk Dr,Suite 320, Baltimore, MD 21228 USA.
EM myeong-jae.jeong-1@nasa.gov
RI Jeong, Myeong/B-8803-2008; Hsu, N. Christina/H-3420-2013; Tsay,
Si-Chee/J-1147-2014; Hansell, Richard/J-2065-2014
FU NASA [NNX06AE10G]
FX We gratefully acknowledge the NOAA Air Resources Laboratory ( ARL) for
the provision of the HYSPLIT transport and dispersion model and READY
website ( http://www.arl.noaa.gov/ ready.html) used in this publication.
This research was funded by NASA grant NNX06AE10G, managed by H. Maring.
NR 22
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U1 0
U2 3
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0094-8276
J9 GEOPHYS RES LETT
JI Geophys. Res. Lett.
PD OCT 17
PY 2008
VL 35
IS 20
AR L20805
DI 10.1029/2008GL035587
PG 6
WC Geosciences, Multidisciplinary
SC Geology
GA 362DA
UT WOS:000260177200006
ER
PT J
AU Zhou, XL
Davis, AJ
Kieber, DJ
Keene, WC
Maben, JR
Maring, H
Dahl, EE
Izaguirre, MA
Sander, R
Smoydzyn, L
AF Zhou, Xianliang
Davis, Andrew J.
Kieber, David J.
Keene, William C.
Maben, John R.
Maring, Hal
Dahl, Elizabeth E.
Izaguirre, Miguel A.
Sander, Rolf
Smoydzyn, Linda
TI Photochemical production of hydroxyl radical and hydroperoxides in water
extracts of nascent marine aerosols produced by bursting bubbles from
Sargasso seawater
SO GEOPHYSICAL RESEARCH LETTERS
LA English
DT Article
ID SEA; CHEMISTRY; PH
AB Marine aerosols produced by bursting bubbles at the ocean surface are highly enriched in organic matter ( OM) relative to seawater. The importance of this OM in the photochemical evolution of marine aerosols, particularly as a source of reactive oxidants, is unknown but likely significant. To investigate oxidant production, nascent aerosols were generated by bubbling zero air through flowing Sargasso seawater and photochemical production of OH radical and hydroperoxide were quantified in aqueous aerosol extracts exposed to solar radiation. Extrapolation to ambient conditions indicates that OM photolysis was the primary in situ source for both OH ( 1.1 x 10(-8) M s(-1)) and hydroperoxides ( 1.7 x 10(-8) M s(-1)) in nascent aerosols; NO(3)(-) photolysis was the primary source in aged, acidified aerosols ( 1.4 x 10(-7) and 4.1 x 10(-8) M s(-1), respectively). In situ OH photoproduction was comparable to gas-phase uptake whereas H(2)O(2) photoproduction was slower. Results provide important constraints for poorly quantified oxidant sources in marine aerosols. Citation: Zhou, X., A. J. Davis, D. J. Kieber, W. C. Keene, J. R. Maben, H. Maring, E. E. Dahl, M. A. Izaguirre, R. Sander, and L. Smoydzyn ( 2008), Photochemical production of hydroxyl radical and hydroperoxides in water extracts of nascent marine aerosols produced by bursting bubbles from Sargasso seawater, Geophys. Res. Lett., 35, L20803, doi: 10.1029/2008GL035418.
C1 [Zhou, Xianliang] New York State Dept Hlth, Wadsworth Ctr, Albany, NY 12201 USA.
[Zhou, Xianliang] SUNY Albany, Sch Publ Hlth, Albany, NY USA.
[Davis, Andrew J.; Kieber, David J.; Dahl, Elizabeth E.] SUNY Syracuse, Coll Environm Sci & Forestry, Dept Chem, Syracuse, NY 13210 USA.
[Keene, William C.; Maben, John R.] Univ Virginia, Dept Environm Sci, Charlottesville, VA 22904 USA.
[Maring, Hal] NASA Headquarters, Radiat Sci Program, Washington, DC 20546 USA.
[Izaguirre, Miguel A.] Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, Miami, FL 33149 USA.
[Sander, Rolf] Max Planck Inst Chem, Air Chem Dept, D-55020 Mainz, Germany.
[Smoydzyn, Linda] Univ Heidelberg, Inst Environm Phys, Heidelberg, Germany.
RP Zhou, XL (reprint author), New York State Dept Hlth, Wadsworth Ctr, Albany, NY 12201 USA.
EM zhoux@wasdworth.org
RI Sander, Rolf/A-5725-2011
OI Sander, Rolf/0000-0001-6479-2092
FU National Science Foundation [ATM-0343082, ATM-0343146, ATM-0343181,
ATM-0343199]
FX We thank two anonymous reviewers for helpful comments and the Bermuda
Institute for Ocean Sciences for outstanding logistical support during
the field deployments. This research was supported by grants from the
National Science Foundation, ATM-0343082 ( HM), ATM-0343146 ( WK),
ATM-0343181 ( XZ), and ATM-0343199 ( DJK).
NR 19
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U1 3
U2 17
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0094-8276
J9 GEOPHYS RES LETT
JI Geophys. Res. Lett.
PD OCT 17
PY 2008
VL 35
IS 20
AR L20803
DI 10.1029/2008GL035418
PG 5
WC Geosciences, Multidisciplinary
SC Geology
GA 362DA
UT WOS:000260177200003
ER
PT J
AU Alkhaled, AA
Michalak, AM
Kawa, SR
Olsen, SC
Wang, JW
AF Alkhaled, Alanood A.
Michalak, Anna M.
Kawa, S. Randolph
Olsen, Seth C.
Wang, Jih-Wang
TI A global evaluation of the regional spatial variability of column
integrated CO2 distributions
SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
LA English
DT Article
ID FSI WFM-DOAS; ATMOSPHERIC CO2; CARBON-DIOXIDE; SCALE FLUXES; SCIAMACHY;
MODEL; CONTINENT; SATELLITE; TRANSPORT; NORTHERN
AB Satellites, such as the Orbiting Carbon Observatory (OCO), are expected to provide global measurements of column-averaged carbon dioxide (CO2) dry-air mole fraction (X-CO2) with the potential of improving the scientific understanding of regional carbon cycle processes and budgets. The satellite data products, however, are expected to have large data gaps due to the satellite track and geophysical limitations (e.g., clouds and aerosols). The satellite data will also be representative of the X-CO2 distribution at the spatial scale of satellite footprints, which is smaller than the resolution of typical transport or process models. Assessing the ability of the retrieved soundings to capture X-CO2 variability over different regions and times, evaluating the representation error associated with using the retrieved X-CO2 product to represent X-CO2 at typical model resolutions, and filling data gaps while providing an estimate of the associated uncertainty all require the evaluation of the spatial variability of X-CO2. In this study, the global spatial covariance structure of X-CO2 is evaluated regionally using CO2 concentrations simulated using the MATCH/CASA model. Results show that regional and temporal changes in the X-CO2 distribution caused by seasonal changes in surface fluxes and transport produce a spatially and temporally variable X-CO2 covariance structure. The effects of model setup and the relatively low resolution of the MATCH/CASA model on the evaluated X-CO2 covariance structure are assessed by comparing the MATCH/CASA results to the spatial variability inferred from the higher-resolution PCTM/GEOS-4 global model, the SiB-RAMS regional model, and aircraft campaign point observations. The comparison with the higher-resolution models and aircraft data shows good agreement with MATCH/CASA results, thus indicating that the presented results provide an adequate representation of X-CO2 variability as will be measured by satellites such as OCO.
C1 [Alkhaled, Alanood A.; Michalak, Anna M.] Univ Michigan, Dept Civil & Environm Engn, Ann Arbor, MI 48109 USA.
[Kawa, S. Randolph] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
[Olsen, Seth C.] Los Alamos Natl Lab, Los Alamos, NM 87545 USA.
[Wang, Jih-Wang] Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA.
RP Alkhaled, AA (reprint author), Univ Michigan, Dept Civil & Environm Engn, Ann Arbor, MI 48109 USA.
EM alanood@umich.edu; amichala@umich.edu
RI Kawa, Stephan/E-9040-2012
FU NASA [NNX08AJ92G]; Kuwait University Scholarship Committee; NASA Carbon
Cycle Science
FX The research described in this paper was partially performed for the
Orbiting Carbon Observatory Project at the Jet Propulsion Laboratory,
California Institute of Technology, under a contract with NASA.
Additional support was provided by NASA under grant NNX08AJ92G "Mapping
Global CO2: Development and Application of Geostatistical
Algorithms for Gap Filling and Uncertainty Assessment for the Orbiting
Carbon Observatory'' issued through the ROSES A. 3 Carbon Cycle Science
Program. Kuwait University Scholarship Committee provided partial
funding for the work presented in this study. The authors gratefully
acknowledge the helpful input provided by Charles Miller (JPL) on early
drafts of this manuscript. The PCTM work was enabled by G. J. Collatz
and Z. Zhu and was supported by NASA Carbon Cycle Science. This paper
was greatly improved as a result of detailed input provided by three
anonymous reviewers.
NR 49
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U1 1
U2 7
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 2169-897X
J9 J GEOPHYS RES-ATMOS
JI J. Geophys. Res.-Atmos.
PD OCT 17
PY 2008
VL 113
IS D20
AR D20303
DI 10.1029/2007JD009693
PG 17
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 362DK
UT WOS:000260178200004
ER
PT J
AU Gosling, JT
Szabo, A
AF Gosling, J. T.
Szabo, A.
TI Bifurcated current sheets produced by magnetic reconnection in the solar
wind
SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
LA English
DT Article
ID PLASMA; MAGNETOTAIL; SUBSTORM; PARTICLE; FLOW
AB We report observations from the Wind spacecraft of Petschek-like magnetic reconnection exhausts and thin current sheets in the solar wind on 19 and 20 November 2007, encompassing a solar wind disturbance driven by a magnetic cloud and followed by a corotating high-speed stream. We have identified an unusually large number (11) of reconnection exhausts in this 2-day interval using 3-s plasma and magnetic field data. Despite the relatively smooth large-scale field rotation associated with the magnetic cloud, five of the exhausts occurred within the cloud; three of those exhausts were associated with extremely small (<18 degrees) local field shear angles. All 11 exhausts contained double-step magnetic field rotations; such double-step rotations are called bifurcated current sheets since they result from the splitting of reconnecting current sheets as an after-effect of the reconnection process. We have also identified 27 current sheets in this 2-day interval that were too thin to be adequately resolved by the 3-s plasma measurement cadence. All of these thin current sheets were well resolved by the 92 ms magnetic field measurement. At least three, and possibly six, of these relatively thin current sheets had double-step magnetic field rotations, indicating the underlying current sheets had probably been disrupted by magnetic reconnection. Current sheets thinner than similar to 3 ion inertial lengths were not present in this data set. The relative lack of such ultrathin current sheets in the solar wind in general suggests that such current sheets usually are quickly disrupted by magnetic reconnection.
C1 [Gosling, J. T.] Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80303 USA.
[Szabo, A.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
RP Gosling, JT (reprint author), Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80303 USA.
EM jack.gosling@lasp.colorado.edu
FU NASA [NNG06GC27G]; NASA TRT
FX We thank R. P. Lepping and R. P. Lin and the CDAWeb for making available
the 92-s and 3-s data used in this paper and the referees for some
useful suggestions. Work at the University of Colorado was supported by
NASA grant NNG06GC27G and the NASA TR&T program.
NR 26
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U1 0
U2 2
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0148-0227
J9 J GEOPHYS RES-SPACE
JI J. Geophys. Res-Space Phys.
PD OCT 17
PY 2008
VL 113
IS A10
AR A10103
DI 10.1029/2008JA013473
PG 8
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 362EK
UT WOS:000260180800002
ER
PT J
AU Masters, A
Achilleos, N
Dougherty, MK
Slavin, JA
Hospodarsky, GB
Arridge, CS
Coates, AJ
AF Masters, A.
Achilleos, N.
Dougherty, M. K.
Slavin, J. A.
Hospodarsky, G. B.
Arridge, C. S.
Coates, A. J.
TI An empirical model of Saturn's bow shock: Cassini observations of shock
location and shape
SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
LA English
DT Article
ID SOLAR-WIND FLOW; MAGNETIC-FIELD; JOVIAN MAGNETOPAUSE; PLASMA
OBSERVATIONS; MAGNETOSPHERE; VOYAGER-2; SYSTEM; ENCOUNTER; DYNAMICS;
JUPITER
AB We present a new empirical model of Saturn's bow shock that utilizes observations from the Cassini spacecraft. Shock crossings are identified in magnetic field and plasma observations made by Cassini between June 2004 and August 2005. The Cassini crossings are then combined with the crossings made during the Saturn flybys of Pioneer 11, Voyager 1, and Voyager 2. Solar wind dynamic pressures for the Cassini crossings are estimated using upstream electron densities determined from Langmuir wave observations made by the Radio and Plasma Wave System. The crossing positions are rotated into aberrated coordinates to correct for the effect of the planet's orbital motion. In the case of Saturn this rotation is by similar to 1 degrees. To correct for solar wind dynamic pressure variations, the crossing positions are normalized to the average pressure < P(SW)> = 0.048 nPa. The model is then obtained by fitting a conic section to the crossings using a nonlinear least squares technique. To validate the assumptions made in constructing the model, we treat the parameters previously assumed to be constants as variables and fit their values using an optimization routine; this leads to a conic section that is within the positional uncertainty of the model. The spacecraft trajectories are considered, and we conclude that they do not significantly bias the model. The new model is compared to the existing models, and the similarities and differences are discussed. We suggest that the new model gives the most accurate empirical representation of the shape and location of Saturn's bow shock.
C1 [Masters, A.; Dougherty, M. K.] Univ London Imperial Coll Sci Technol & Med, Blackett Lab, Space & Atmospher Phys Grp, London SW7 2BW, England.
[Hospodarsky, G. B.] Univ Iowa, Dept Phys & Astron, Iowa City, IA 52242 USA.
[Slavin, J. A.] NASA, Goddard Space Flight Ctr, Heliophys Sci Div, Greenbelt, MD 20771 USA.
[Arridge, C. S.; Coates, A. J.] Univ Coll London, Dept Space & Climate Phys, Mullard Space Sci Lab, Dorking RH5 6NT, Surrey, England.
[Achilleos, N.] UCL, Dept Phys & Astron, Atmospher Phys Lab, London WC1E 6BT, England.
[Arridge, C. S.; Coates, A. J.] UCL, Ctr Planetary Sci, London, England.
RP Masters, A (reprint author), Univ London Imperial Coll Sci Technol & Med, Blackett Lab, Space & Atmospher Phys Grp, Prince Consort Rd, London SW7 2BW, England.
EM adam.masters02@imperial.ac.uk
RI Arridge, Christopher/A-2894-2009; Achilleos, Nicholas/C-1647-2008;
Coates, Andrew/C-2396-2008; Slavin, James/H-3170-2012;
OI Arridge, Christopher/0000-0002-0431-6526; Coates,
Andrew/0000-0002-6185-3125; Slavin, James/0000-0002-9206-724X;
Achilleos, Nicholas/0000-0002-5886-3509; Hospodarsky,
George/0000-0001-9200-9878
FU Science and Technology Facilities Council [PP/D00084X/1]
NR 60
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U1 1
U2 5
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0148-0227
J9 J GEOPHYS RES-SPACE
JI J. Geophys. Res-Space Phys.
PD OCT 17
PY 2008
VL 113
IS A10
AR A10210
DI 10.1029/2008JA013276
PG 18
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 362EK
UT WOS:000260180800001
ER
PT J
AU Sperhake, U
Cardoso, V
Pretorius, F
Berti, E
Gonzalez, JA
AF Sperhake, Ulrich
Cardoso, Vitor
Pretorius, Frans
Berti, Emanuele
Gonzalez, Jose A.
TI High-Energy Collision of Two Black Holes
SO PHYSICAL REVIEW LETTERS
LA English
DT Article
ID HEAD-ON COLLISIONS; GRAVITATIONAL-RADIATION; NUMERICAL RELATIVITY;
APPARENT HORIZONS; INITIAL DATA; DIMENSIONS; MILLIMETER; HIERARCHY;
SPEED; LIGHT
AB We study the head-on collision of two highly boosted equal mass, nonrotating black holes. We determine the waveforms, radiated energies, and mode excitation in the center of mass frame for a variety of boosts. For the first time we are able to compare analytic calculations, black-hole perturbation theory, and strong field, nonlinear numerical calculations for this problem. Extrapolation of our results, which include velocities of up to 0.94c, indicate that in the ultrarelativistic regime about 14 +/- 3% of the energy is converted into gravitational waves. This gives rise to a luminosity of order 10(-2)c(5)/G, the largest known so far in a black-hole merger.
C1 [Sperhake, Ulrich] Univ Jena, Inst Theoret Phys, D-07743 Jena, Germany.
[Cardoso, Vitor] Inst Super Tecn, Dept Fis, CENTRA, P-1049001 Lisbon, Portugal.
[Cardoso, Vitor] Univ Mississippi, Dept Phys & Astron, University, MS 38677 USA.
[Pretorius, Frans] Princeton Univ, Dept Phys, Princeton, NJ 08544 USA.
[Berti, Emanuele] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[Gonzalez, Jose A.] Univ Michoacana, Inst Fis & Matemat, Morelia 58040, Michoacan, Mexico.
RP Sperhake, U (reprint author), Univ Jena, Inst Theoret Phys, D-07743 Jena, Germany.
RI Berti, Emanuele/C-9331-2016; Cardoso, Vitor/K-1877-2015
OI Berti, Emanuele/0000-0003-0751-5130; Cardoso, Vitor/0000-0003-0553-0433
FU DFG [SFB/TR7]; FCT-Portugal [PTDC/FIS/64175/2006, POCI/FP/81915/2007];
Fulbright Foundation; NASA Postdoctoral Program at JPL/Caltech; Oak
Ridge Associated Universities; Alfred P. Sloan Foundation; NSF
[PHY-0745779]
FX This work was supported in part by DFG grant SFB/TR7, by FCT-Portugal
through projects PTDC/FIS/64175/2006 and POCI/FP/81915/2007, and by the
Fulbright Foundation (V. C.). E. B. was supported by the NASA
Postdoctoral Program at JPL/Caltech, administered by Oak Ridge
Associated Universities through a contract with NASA. F. P. was
supported by the Alfred P. Sloan Foundation and NSF PHY-0745779.
Computations were performed at LRZ Munich, Milipeia at CFC in Coimbra,
and the Woodhen cluster at Princeton University.
NR 40
TC 101
Z9 102
U1 0
U2 3
PU AMER PHYSICAL SOC
PI COLLEGE PK
PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA
SN 0031-9007
EI 1079-7114
J9 PHYS REV LETT
JI Phys. Rev. Lett.
PD OCT 17
PY 2008
VL 101
IS 16
AR 161101
DI 10.1103/PhysRevLett.101.161101
PG 4
WC Physics, Multidisciplinary
SC Physics
GA 361QD
UT WOS:000260141300006
PM 18999655
ER
PT J
AU Johnson, AP
Cleaves, HJ
Dworkin, JP
Glavin, DP
Lazcano, A
Bada, JL
AF Johnson, Adam P.
Cleaves, H. James
Dworkin, Jason P.
Glavin, Daniel P.
Lazcano, Antonio
Bada, Jeffrey L.
TI The Miller volcanic spark discharge experiment
SO SCIENCE
LA English
DT Article
ID AMINO-ACIDS
C1 [Bada, Jeffrey L.] Univ Calif San Diego, Scripps Inst Oceanog, La Jolla, CA 92093 USA.
[Johnson, Adam P.] Indiana Univ, Interdisciplinary Biochem Program, Bloomington, IN 47401 USA.
[Cleaves, H. James] Carnegie Inst Washington, Washington, DC 20015 USA.
[Dworkin, Jason P.; Glavin, Daniel P.] NASA, Goddard Space Flight Ctr, Solar Syst Explorat Div, Greenbelt, MD 20771 USA.
[Lazcano, Antonio] Univ Nacl Autonoma Mexico, Fac Ciencias, Mexico City 04510, DF, Mexico.
RP Bada, JL (reprint author), Univ Calif San Diego, Scripps Inst Oceanog, La Jolla, CA 92093 USA.
EM jbada@ucsd.edu
RI Glavin, Daniel/D-6194-2012; Dworkin, Jason/C-9417-2012;
OI Glavin, Daniel/0000-0001-7779-7765; Dworkin, Jason/0000-0002-3961-8997;
Cleaves, Henderson/0000-0003-4101-0654
NR 8
TC 105
Z9 111
U1 15
U2 97
PU AMER ASSOC ADVANCEMENT SCIENCE
PI WASHINGTON
PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA
SN 0036-8075
J9 SCIENCE
JI Science
PD OCT 17
PY 2008
VL 322
IS 5900
BP 404
EP 404
DI 10.1126/science.1161527
PG 1
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA 360YK
UT WOS:000260094500036
PM 18927386
ER
PT J
AU Volkov, DL
Lee, T
Fu, LL
AF Volkov, Denis L.
Lee, Tong
Fu, Lee-Lueng
TI Eddy-induced meridional heat transport in the ocean
SO GEOPHYSICAL RESEARCH LETTERS
LA English
DT Article
ID CIRCULATION; VARIABILITY; MODEL
AB A global ocean data synthesis product at eddy-permitting resolution from Estimating the Circulation and Climate of the Ocean, Phase II (ECCO2) project are used to estimate the oceanic eddy heat transport. We show that in a number of locations the time-mean eddy heat transport constitutes a considerable portion of the total time-mean heat transport, in particular, in the tropics, in the Southern Ocean and in the Kuroshio Current. This research demonstrates that the variability of the eddy heat transport is a significant contributor to the variability of the total heat transport and globally it explains about 1/3 of its variance. Eddies are also found to explain a significant portion of the seasonal-interannual heat transport variance. Citation: Volkov, D. L., T. Lee, and L.-L. Fu (2008), Eddy-induced meridional heat transport in the ocean, Geophys. Res. Lett., 35, L20601, doi:10.1029/2008GL035490.
C1 [Volkov, Denis L.; Lee, Tong; Fu, Lee-Lueng] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Volkov, DL (reprint author), CALTECH, Jet Prop Lab, Mail Stop 300-314,4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM dvolkov@caltech.edu
RI Volkov, Denis/A-6079-2011
OI Volkov, Denis/0000-0002-9290-0502
FU National Aeronautics and Space Administration
FX This research was carried out at the Jet Propulsion Laboratory,
California Institute of Technology, within the framework of the ECCO2
project, sponsored by the National Aeronautics and Space Administration.
The efforts of all members of the ECCO2 group involved in running
model-simulations are appreciated.
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PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0094-8276
J9 GEOPHYS RES LETT
JI Geophys. Res. Lett.
PD OCT 16
PY 2008
VL 35
IS 20
AR L20601
DI 10.1029/2008GL035490
PG 5
WC Geosciences, Multidisciplinary
SC Geology
GA 362CZ
UT WOS:000260177100004
ER
PT J
AU Zeng, J
Han, QY
Wang, J
AF Zeng, Jing
Han, Qingyuan
Wang, Jun
TI High-spectral resolution simulation of polarization of skylight:
Sensitivity to aerosol vertical profile
SO GEOPHYSICAL RESEARCH LETTERS
LA English
DT Article
ID RETRIEVAL; OCEAN; SCATTERING
AB A vector radiative transfer model was used in conjunction with the line-by-line radiative transfer model and the database of high-resolution transmission (HITRAN) molecular absorption to simulate the degree of linear polarization of skylight in cloud-free conditions. Differences between simulated and measured polarization data in high-spectral resolution are found to be within 1% after aerosol scattering and gas absorptions are carefully considered. Limiting experiments are conducted at wavelengths around 0.760-0.765 mu m O(2)-A absorption band for the same columnar aerosol optical thickness but different aerosol profiles. Results showed that the degree of linear polarization of skylight at surface varies strongly and is sensitive to the vertical change of tropospheric aerosol mass (or extinction) as the wavelengths approach to the edge of O(2)-A absorption band. However, such sensitivity is minimal at all wavelengths when the aerosol composition or single scattering properties are vertically homogeneous. This study suggests that the polarization data can be used together with radiance data to constrain the simulation of vertical distribution of aerosol composition in chemistry transport models. Citation: Zeng, J., Q. Han, and J. Wang (2008), High-spectral resolution simulation of polarization of skylight: Sensitivity to aerosol vertical profile, Geophys. Res. Lett., 35, L20801, doi: 10.1029/ 2008GL035645.
C1 [Zeng, Jing; Han, Qingyuan] Univ Alabama, Dept Atmospher Sci, Huntsville, AL 35805 USA.
[Wang, Jun] Univ Nebraska, Dept Geosci, Lincoln, NE 68588 USA.
[Wang, Jun] Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21228 USA.
[Wang, Jun] NASA, Goddard Space Flight Ctr, Climate & Radiat Branch, Atmospheres Lab, Greenbelt, MD 20771 USA.
RP Zeng, J (reprint author), NASA, Goddard Space Flight Ctr, Earth Resource Technol Inc, Code 614-3, Greenbelt, MD 20771 USA.
EM jwang7@unl.edu
RI Wang, Jun/A-2977-2008
OI Wang, Jun/0000-0002-7334-0490
FU Office of Science, U. S. Department of Energy [DE-FG02-08ER64669]; NASA
[NNX08AQ86G, NNX08AL54G]
FX This research was supported by the Atmospheric Radiation Measurement
Program, Office of Science, U. S. Department of Energy, grant
DE-FG02-08ER64669. J. Wang was supported by the NASA Earth Sciences New
Investigator Program (NNX08AQ86G), NASA Radiation Science Program
(NNX08AL54G), and NASA GSFC Yoram J. Kaufman Visiting Fellow program
under the administration of UMBC/ GEST. We thank I. Aben for providing
polarization data, and one anonymous reviewer for suggestions on adding
Figure 2 and constructive comments on Figures 3 and 4 of this paper.
NR 19
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PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0094-8276
J9 GEOPHYS RES LETT
JI Geophys. Res. Lett.
PD OCT 16
PY 2008
VL 35
IS 20
AR L20801
DI 10.1029/2008GL035645
PG 5
WC Geosciences, Multidisciplinary
SC Geology
GA 362CZ
UT WOS:000260177100006
ER
PT J
AU McMillan, WW
Warner, JX
Comer, MM
Maddy, E
Chu, A
Sparling, L
Eloranta, E
Hoff, R
Sachse, G
Barnet, C
Razenkov, I
Wolf, W
AF McMillan, W. W.
Warner, J. X.
Comer, M. McCourt
Maddy, E.
Chu, A.
Sparling, L.
Eloranta, E.
Hoff, R.
Sachse, G.
Barnet, C.
Razenkov, I.
Wolf, W.
TI AIRS views transport from 12 to 22 July 2004 Alaskan/Canadian fires:
Correlation of AIRS CO and MODIS AOD with forward trajectories and
comparison of AIRS CO retrievals with DC-8 in situ measurements during
INTEX-A/ICARTT
SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
LA English
DT Article
ID RESOLUTION IMAGING SPECTRORADIOMETER; CARBON-MONOXIDE CONCENTRATION;
FOREST-FIRES; NORTHERN-HEMISPHERE; EARTHS ATMOSPHERE; OZONE POLLUTION;
SCALE TRANSPORT; TROPOSPHERE; EMISSIONS; SATELLITE
AB We present observations of transport of tropospheric carbon monoxide (CO) obtained by the Atmospheric Infrared Sounder (AIRS) on board NASA's Aqua satellite during the Intercontinental Chemical Transport Experiment-North America (INTEX-A) field campaign in the summer of 2004, part of the International Consortium for Atmospheric Research on Transport and Transformation (ICARTT). In situ measurements from NASA's DC-8 provide crucial assessment of AIRS midtropospheric (400-500 mbar) CO retrievals. For the nine best INTEX-A profiles, convolution of the in situ profiles with AIRS verticality functions demonstrates version 4 AIRS CO retrievals between 400 and 500 mbar are biased high by approximately 8% with a standard deviation slightly less than 5%. The 400-500 mbar region is the only portion of the version 4 AIRS CO retrievals that can be validated as presented here. In some cases, AIRS CO retrievals may be sensitive to CO in the lower to midtroposphere (800-500 mbar). Focusing on one major episode, we investigate transport of CO from a large fire outbreak in the Alaskan/Canadian Yukon region from 11 to 14 July 2004 and follow it downwind to the southeastern United States and Europe by 22 July 2004. Comparison of AIRS CO maps and forward trajectories from fire locations reveals substantial variations in fire emissions especially emission injection height. Any useful forecast model must control for such fire emission variabilities to predict correctly the downwind impact. To match the forward trajectory analyses with AIRS CO observations requires some fires to have directly injected emissions to at least 500 mbar and perhaps as high as 300 mbar. Ground-based lidar observations show smoke plume altitudes from 3 to 11 km over Wisconsin and from 1 to 4 km over Mary land in agreement with the forward trajectories. The Wisconsin lidar profiles on the afternoon of 18 July 2004 constrain the altitude of CO-rich smoke observed by AIRS and MODIS to lie between 2 and 5.5 km above the surface, roughly 800 to 500 mbar. We find that changes in the correlation between AIRS CO and MODIS AOD reflect changes in the CO vertical distribution during this event. This finding is confirmed by in situ measurements, meteorological analyses, and forward trajectory analyses.
C1 [McMillan, W. W.; Sparling, L.] Univ Maryland, Dept Phys, Baltimore, MD 21250 USA.
[McMillan, W. W.; Warner, J. X.; Chu, A.; Hoff, R.] Univ Maryland, Joint Ctr Earth Syst Technol, Baltimore, MD 21250 USA.
[Comer, M. McCourt] So High Sch, Dept Sci, Harwood, MD 20776 USA.
[Maddy, E.] QSS Grp Inc, Camp Springs, MD 20746 USA.
[Eloranta, E.; Razenkov, I.] Univ Wisconsin, Ctr Space Sci & Engn, Madison, WI 53706 USA.
[Sachse, G.] NASA, Langley Res Ctr, Hampton, VA 23681 USA.
[Barnet, C.; Wolf, W.] NOAA, Natl Environm Satellite Data & Informat Serv, Ctr Satellite Applicat & Res, Camp Springs, MD 20746 USA.
RP McMillan, WW (reprint author), Univ Maryland, Dept Phys, 1000 Hilltop Circle, Baltimore, MD 21250 USA.
EM mcmillan@umbc.edu
RI Maddy, Eric/G-3683-2010; Barnet, Christopher/F-5573-2010; Wolf,
Walter/E-7935-2011
OI Maddy, Eric/0000-0003-1151-339X; Wolf, Walter/0000-0002-2102-8833
FU NASA; NASA [NAG5-11163, NAG5-11653, NNG04GN42G, NNG06GB06G]; NOAA CREST;
NSF
FX The authors gratefully acknowledge support from the NASA EOS Program for
W. W. M., X.J.W., and M. M. C. through NASA grants NAG5-11163,
NAG5-11653, NNG04GN42G, and NNG06GB06G. R. M. H. was supported through a
grant from the NOAA CREST at CUNY. E. E. is thankful for the support of
NSF. We thank Mark Schoeberl for the trajectory code. Special thanks to
the entire AIRS Team and Vickie Connors for her diligent review of this
manuscript. W. W. M. thanks Rae Force for her patient support. AIRS CO
data are available upon request and online.
NR 93
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U2 10
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 2169-897X
EI 2169-8996
J9 J GEOPHYS RES-ATMOS
JI J. Geophys. Res.-Atmos.
PD OCT 16
PY 2008
VL 113
IS D20
AR D20301
DI 10.1029/2007JD009711
PG 18
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 362DJ
UT WOS:000260178100002
ER
PT J
AU Liu, X
Zhang, Y
Cassell, AM
Cruden, BA
AF Liu, Xi
Zhang, Yi
Cassell, Alan M.
Cruden, Brett A.
TI Implications of catalyst control for carbon nanotube based thermal
interface materials
SO JOURNAL OF APPLIED PHYSICS
LA English
DT Article
ID CONDUCTIVITY; GROWTH; ARRAYS; FILMS; CONDUCTANCE; DENSE
AB We report on the characterization of a carbon nanotube (CNT) based thermal interface material grown by chemical vapor deposition on catalysts formed by a micelle templating method. The micelle templating method allows for controllable diameter and density in the CNT array that is not easily achieved by other techniques. In this work, we characterize the activity of the catalyst to be at least 10% by a root-counting method. This activity differs from that reported in other works, although the disparity may be largely explained by understanding the approximations in other characterizations. Characterization of thermal interface resistance shows nonmonotonic dependencies on length and catalyst/nanotube density, with optimum values of approximately 0.08 K cm(2)/W. This exceeds that characterized by others in the literature for a single CNT film interface and state of the art thermal greases. Dependencies on length and density are explained by considering how the compliancy of the CNT array is impacted by these variables. (C) 2008 American Institute of Physics. [DOI: 10.1063/1.2999644]
C1 [Liu, Xi; Zhang, Yi; Cassell, Alan M.; Cruden, Brett A.] Ames Univ, Affiliated Res Ctr, NASA, Moffett Field, CA 94035 USA.
[Liu, Xi] Univ Calif Santa Cruz, Santa Cruz, CA 95064 USA.
RP Cruden, BA (reprint author), Ames Univ, Affiliated Res Ctr, NASA, Moffett Field, CA 94035 USA.
EM brett.a.cruden@nasa.gov
FU UC Discovery Grant Program
FX Funding for this work was provided by the UC Discovery Grant Program.
NR 32
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U1 0
U2 10
PU AMER INST PHYSICS
PI MELVILLE
PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1,
MELVILLE, NY 11747-4501 USA
SN 0021-8979
EI 1089-7550
J9 J APPL PHYS
JI J. Appl. Phys.
PD OCT 15
PY 2008
VL 104
IS 8
AR 084310
DI 10.1063/1.2999644
PG 5
WC Physics, Applied
SC Physics
GA 367SG
UT WOS:000260572100099
ER
PT J
AU Maes, OC
An, J
Sarojini, H
Wu, HL
Wang, E
AF Maes, Olivier C.
An, Jin
Sarojini, Harshini
Wu, Honglu
Wang, Eugenia
TI Changes in MicroRNA Expression Patterns in Human Fibroblasts After
Low-LET Radiation
SO JOURNAL OF CELLULAR BIOCHEMISTRY
LA English
DT Article
DE FIBROBLAST; LOW LINEAR ENERGY TRANSFER; MICRORNA; RADIATION
ID TRANSFORMATION IN-VITRO; IONIZING-RADIATION; GENE-EXPRESSION; MICROARRAY
ANALYSIS; CELLS; PROFILES; IRRADIATION; STRESS; IDENTIFICATION;
CALRETICULIN
AB Exposure to radiation provokes cellular responses controlled in part by gene expression networks. MicroRNAs (miRNAs) are small non-coding RNAs which mostly regulate gene expression by degrading the messages or inhibiting translation. Here, we investigated changes in miRNA expression patterns after low (0.1 Gy) and high (2.0 Gy) doses of X-ray in human fibroblasts. At early (0.5 h) and late (6 and 24 h) time points, irradiation caused qualitative and quantitative differences in the down-regulation of miRNA levels, including miR-92b, 137, 660, and 656. A transient up-regulation of miRNAs was observed after 2 It post-irradiation following high doses of radiation, including miR-558 and 662. MicroRNA levels were inversely correlated with targets from mRNA and proteomic profiling after 2.0 Gy of radiation. MicroRNAs miR-579, 608, 548-3p, and 585 are noted for targeting genes involved in radioresponsive mechanisms, such as cell cycle checkpoint and apoptosis. We suggest here a model in which miRNAs may act as "hub" regulators of specific cellular responses, immediately down-regulated so as to stimulate DNA repair mechanisms, followed by up-regulation involved in suppressing apoptosis for cell survival. Taken together, miRNAs may mediate signaling pathways in sequential fashion in response to radiation, and may serve as biodosimetric markers of radiation exposure. J. Cell. Biochem. 105: 824-834, 2008. (c) 2008 Wiley-Liss. Inc.
C1 [Wang, Eugenia] Univ Louisville, Dept Biochem & Mol Biol, Sch Med, Gheens Ctr Aging, Louisville, KY 40202 USA.
[Wu, Honglu] NASA, Lyndon B Johnson Space Ctr, Radiat Biophys Lab, Houston, TX 77058 USA.
RP Wang, E (reprint author), Univ Louisville, Dept Biochem & Mol Biol, Sch Med, Gheens Ctr Aging, 580 S Preston St, Louisville, KY 40202 USA.
EM eugenia.wang@louisville.edu
FU National Aeronautics and Space Administration; NASA Johnson Space
Center, Houston, Texas [NNJ06HF62G]
FX Grant sponsor: National Aeronautics and Space Administration, NASA
Johnson Space Center, Houston, Texas; Grant number: NNJ06HF62G.
NR 47
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U1 0
U2 12
PU WILEY-LISS
PI HOBOKEN
PA DIV JOHN WILEY & SONS INC, 111 RIVER ST, HOBOKEN, NJ 07030 USA
SN 0730-2312
J9 J CELL BIOCHEM
JI J. Cell. Biochem.
PD OCT 15
PY 2008
VL 105
IS 3
BP 824
EP 834
DI 10.1002/jcb.21878
PG 11
WC Biochemistry & Molecular Biology; Cell Biology
SC Biochemistry & Molecular Biology; Cell Biology
GA 388MH
UT WOS:000262023400022
PM 18729083
ER
PT J
AU Smith, PH
Tamppari, L
Arvidson, RE
Bass, D
Blaney, D
Boynton, W
Carswell, A
Catling, D
Clark, B
Duck, T
DeJong, E
Fisher, D
Goetz, W
Gunnlaugsson, P
Hecht, M
Hipkin, V
Hoffman, J
Hviid, S
Keller, H
Kounaves, S
Lange, CF
Lemmon, M
Madsen, M
Malin, M
Markiewicz, W
Marshall, J
McKay, C
Mellon, M
Michelangeli, D
Ming, D
Morris, R
Renno, N
Pike, WT
Staufer, U
Stoker, C
Taylor, P
Whiteway, J
Young, S
Zent, A
AF Smith, P. H.
Tamppari, L.
Arvidson, R. E.
Bass, D.
Blaney, D.
Boynton, W.
Carswell, A.
Catling, D.
Clark, B.
Duck, T.
DeJong, E.
Fisher, D.
Goetz, W.
Gunnlaugsson, P.
Hecht, M.
Hipkin, V.
Hoffman, J.
Hviid, S.
Keller, H.
Kounaves, S.
Lange, C. F.
Lemmon, M.
Madsen, M.
Malin, M.
Markiewicz, W.
Marshall, J.
McKay, C.
Mellon, M.
Michelangeli, D.
Ming, D.
Morris, R.
Renno, N.
Pike, W. T.
Staufer, U.
Stoker, C.
Taylor, P.
Whiteway, J.
Young, S.
Zent, A.
TI Introduction to special section on the Phoenix Mission: Landing Site
Characterization Experiments, Mission Overviews, and Expected Science
SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS
LA English
DT Article
ID MARS PATHFINDER; MERIDIANI-PLANUM; ICE; DEPOSITS; SURFACE; IMAGER;
WATER; OBLIQUITY; HYDROGEN; ODYSSEY
AB Phoenix, the first Mars Scout mission, capitalizes on the large NASA investments in the Mars Polar Lander and the Mars Surveyor 2001 missions. On 4 August 2007, Phoenix was launched to Mars from Cape Canaveral, Florida, on a Delta 2 launch vehicle. The heritage derived from the canceled 2001 lander with a science payload inherited from MPL and 2001 instruments gives significant advantages. To manage, build, and test the spacecraft and its instruments, a partnership has been forged between the Jet Propulsion Laboratory, the University of Arizona (home institution of principal investigator P. H. Smith), and Lockheed Martin in Denver; instrument and scientific contributions from Canada and Europe have augmented the mission. The science mission focuses on providing the ground truth for the 2002 Odyssey discovery of massive ice deposits hidden under surface soils in the circumpolar regions. The science objectives, the instrument suite, and the measurements needed to meet the objectives are briefly described here with reference made to more complete instrument papers included in this special section. The choice of a landing site in the vicinity of 68 degrees N and 233 degrees E balances scientific value and landing safety. Phoenix will land on 25 May 2008 during a complex entry, descent, and landing sequence using pulsed thrusters as the final braking strategy. After a safe landing, twin fan-like solar panels are unfurled and provide the energy needed for the mission. Throughout the 90-sol primary mission, activities are planned on a tactical basis by the science team; their requests are passed to an uplink team of sequencing engineers for translation to spacecraft commands. Commands are transmitted each Martian morning through the Deep Space Network by way of a Mars orbiter to the spacecraft. Data are returned at the end of the Martian day by the same path. Satisfying the mission's goals requires digging and providing samples of interesting layers to three on-deck instruments. By verifying that massive water ice is found near the surface and determining the history of the icy soil by studying the mineralogical, chemical, and microscopic properties of the soil grains, Phoenix will address questions concerning the effects of climate change in the northern plains. A conclusion that unfrozen water has modified the soil naturally leads to speculation as to the biological potential of the soil, another scientific objective of the mission.
C1 [Smith, P. H.; Boynton, W.] Univ Arizona, Dept Planetary Sci, Tucson, AZ 85721 USA.
[Tamppari, L.; Bass, D.; Blaney, D.; Hecht, M.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[Arvidson, R. E.] Washington Univ, Dept Earth & Planetary Sci, St Louis, MO 63130 USA.
[Carswell, A.] Optech Inc, Vaughan, ON L4K 5Z8, Canada.
[Catling, D.] Univ Bristol, Dept Earth Sci, Bristol BS8 1RJ, Avon, England.
[Duck, T.] Dalhousie Univ, Dept Phys & Atmospher Sci, Halifax, NS B3H 1Z9, Canada.
[Fisher, D.] Geol Survey Canada, Nat Resources Canada, Northern Div, Glaciol Sect, Ottawa, ON K1A 0E8, Canada.
[Goetz, W.; Hviid, S.; Keller, H.; Markiewicz, W.] Max Planck Inst Solar Syst Res, D-37191 Katlenburg Lindau, Germany.
[Gunnlaugsson, P.] Univ Aarhus, Dept Phys & Astron, DK-8000 Aarhus C, Denmark.
[Hipkin, V.] Canadian Space Agcy, St Hubert, PQ J3Y 8Y9, Canada.
[Hoffman, J.] Univ Texas Dallas, Dept Phys, Dallas, TX 75080 USA.
[Kounaves, S.; Young, S.] Tufts Univ, Dept Chem, Medford, MA 02155 USA.
[Lange, C. F.] Univ Alberta, Dept Mech Engn, Edmonton, AB T6G 2G8, Canada.
[Lemmon, M.] Texas A&M Univ, Dept Atmospher Sci, College Stn, TX 77843 USA.
[Madsen, M.] Univ Copenhagen, Niels Bohr Inst, DK-2100 Copenhagen, Denmark.
[Malin, M.] Malin Space Sci Syst, San Diego, CA 92191 USA.
[Marshall, J.] SETI Inst, Mountain View, CA 94043 USA.
[McKay, C.; Stoker, C.; Zent, A.] NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA.
[Mellon, M.] Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80309 USA.
[Ming, D.; Morris, R.] NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA.
[Pike, W. T.] Univ London Imperial Coll Sci Technol & Med, Dept Elect & Elect Engn, London SW7 2AZ, England.
[Renno, N.] Univ Michigan, Dept Atmospher Ocean & Space Sci, Ann Arbor, MI 48109 USA.
[Staufer, U.] Univ Neuchatel, Inst Microtechnol, CH-2000 Neuchatel, Switzerland.
[Michelangeli, D.; Taylor, P.; Whiteway, J.] York Univ, Dept Earth & Space Sci & Engn, N York, ON M3J 1P3, Canada.
[Fisher, D.] Univ Ottawa, Dept Earth Sci, Ottawa, ON, Canada.
RP Smith, PH (reprint author), Univ Arizona, Dept Planetary Sci, Tucson, AZ 85721 USA.
EM psmith@lpl.arizona.edu
RI Lemmon, Mark/E-9983-2010; Catling, David/D-2082-2009; Madsen,
Michael/B-2182-2015; Mellon, Michael/C-3456-2016; Staufer,
Urs/J-6866-2016;
OI Lemmon, Mark/0000-0002-4504-5136; Madsen, Michael/0000-0003-2789-4713;
Staufer, Urs/0000-0002-3519-6467; Catling, David/0000-0001-5646-120X;
Kounaves, Samuel/0000-0002-2629-4831
NR 47
TC 58
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U1 1
U2 17
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 2169-9097
J9 J GEOPHYS RES-PLANET
JI J. Geophys. Res.-Planets
PD OCT 15
PY 2008
VL 113
AR E00A18
DI 10.1029/2008JE003083
PG 16
WC Geochemistry & Geophysics
SC Geochemistry & Geophysics
GA 362DY
UT WOS:000260179600001
ER
PT J
AU Tumer, K
Agogino, AK
AF Tumer, Kagan
Agogino, Adrian K.
TI Ensemble clustering with voting active clusters
SO PATTERN RECOGNITION LETTERS
LA English
DT Article
DE cluster ensembles; consensus clustering; distributed clustering;
adaptive clustering
AB Clustering is an integral part of pattern recognition problems and is connected to both the data reduction and the data understanding steps. Combining multiple clusterings into an ensemble clustering is critical in many real world applications, particularly for domains with large data sets, high-dimensional feature sets and proprietary data. This paper presents voting active clusters (VACs), a method for combining multiple "base" clusterings into a single unified "ensemble" Clustering that is robust against missing data and does not require all the data to be collected in one central location. In this approach, separate Processing centers produce many base clusterings based on some portion of the data. The clusterings Of Such separate processing centers are then pooled to produce a unified ensemble Clustering through a voting mechanism. The major contribution of this work is in providing an adaptive voting method by which the clusterings (e.g., spatially distributed processing centers) update their votes in order to maximize an overall quality measure. Our results show that this method achieves comparable or better performance than traditional Cluster ensemble methods in noise-free conditions, and remains effective in noisy scenarios where many traditional methods are inapplicable. (c) 2008 Elsevier B.V. All rights reserved.
C1 [Tumer, Kagan] Oregon State Univ, Corvallis, OR 97330 USA.
[Agogino, Adrian K.] NASA, Ames Res Ctr, UCSC, Moffett Field, CA 94035 USA.
RP Tumer, K (reprint author), Oregon State Univ, 204 Rogers Hall, Corvallis, OR 97330 USA.
EM kagan.tumer@oregonstate.edu; adrian@email.arc.nasa.gov
NR 31
TC 19
Z9 25
U1 0
U2 3
PU ELSEVIER SCIENCE BV
PI AMSTERDAM
PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS
SN 0167-8655
J9 PATTERN RECOGN LETT
JI Pattern Recognit. Lett.
PD OCT 15
PY 2008
VL 29
IS 14
BP 1947
EP 1953
DI 10.1016/j.patrec.2008.06.011
PG 7
WC Computer Science, Artificial Intelligence
SC Computer Science
GA 355ME
UT WOS:000259712200006
ER
PT J
AU Hall, DK
Box, JE
Casey, KA
Hook, SJ
Shuman, CA
Steffen, K
AF Hall, Dorothy K.
Box, Jason E.
Casey, Kimberly A.
Hook, Simon J.
Shuman, Christopher A.
Steffen, Konrad
TI Comparison of satellite-derived and in-situ observations of ice and snow
surface temperatures over Greenland
SO REMOTE SENSING OF ENVIRONMENT
LA English
DT Article
DE Greenland Ice Sheet; MODIS; ASTER; ETM; LST
ID SPACEBORNE THERMAL EMISSION; REFLECTION RADIOMETER ASTER; POLAR
PATHFINDER DATASET; RADIATION PROPERTIES; ARCTIC SURFACE; RECENT TRENDS;
INFRARED DATA; CLEAR-SKY; LAND; MODIS
AB The most practical way to get spatially broad and continuous measurements of the surface temperature in the data-sparse cryosphere is by satellite remote sensing. The uncertainties in satellite-derived LSTs must be understood to develop internally-consistent decade-scale land surface temperature (LST) records needed for climate studies. In this work we assess satellite-derived "clear-sky" LST products from the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), and LSTs derived from the Enhanced Thematic Mapper Plus (ETM+) over snow and ice on Greenland. When possible, we compare satellite-derived LSTs with in-situ air temperature observations from Greenland Climate Network (GC-Net) automatic weather stations (AWS). We find that MODIS, ASTER and ETM+ provide reliable and consistent LSTs under clear-sky conditions and relatively-flat terrain over snow and ice targets over a range of temperatures from -40 to 0 degrees C. The satellite-derived LSTs agree within a relative RMS uncertainty of -0.5 degrees C. The good agreement among the LSTs derived from the various satellite instruments is especially notable since different spectral channels and different retrieval algorithms are used to calculate LST from the raw satellite data. The AWS record in-situ data at a "point" while the satellite instruments record data over an area varying in size from: 57 x 57 m (ETM+), 90 x 90 m (ASTER), or to 1 x 1 km (MODIS). Surface topography and other factors contribute to variability of LST within a pixel, thus the AWS measurements may not be representative of the LST of the pixel. Without more information on the local spatial patterns of LST, the AWS LST cannot be considered valid ground truth for the satellite measurements, with RMS uncertainty similar to 2 degrees C. Despite the relatively large AWS-derived uncertainty, we find LST data are characterized by high accuracy but have uncertain absolute precision. (c) 2008 Elsevier Inc. All rights reserved.
C1 [Hall, Dorothy K.] NASA, Goddard Space Flight Ctr, Cryospher Sci Branch, Greenbelt, MD 20771 USA.
[Box, Jason E.] Ohio State Univ, Dept Geog, Columbus, OH 43210 USA.
[Casey, Kimberly A.] Wyle Labs Inc, Mclean, VA 22102 USA.
[Hook, Simon J.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[Shuman, Christopher A.] Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21228 USA.
[Steffen, Konrad] Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA.
RP Hall, DK (reprint author), NASA, Goddard Space Flight Ctr, Cryospher Sci Branch, Code 614-1, Greenbelt, MD 20771 USA.
EM dorothy.k.hal@nasa.gov
RI Hall, Dorothy/D-5562-2012; Casey, Kimberly/A-4478-2013; Steffen,
Konrad/C-6027-2013; Box, Jason/H-5770-2013
OI Casey, Kimberly/0000-0002-6115-7525; Steffen,
Konrad/0000-0001-8658-1026;
NR 47
TC 40
Z9 41
U1 0
U2 23
PU ELSEVIER SCIENCE INC
PI NEW YORK
PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA
SN 0034-4257
J9 REMOTE SENS ENVIRON
JI Remote Sens. Environ.
PD OCT 15
PY 2008
VL 112
IS 10
BP 3739
EP 3749
DI 10.1016/j.rse.2008.05.007
PG 11
WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic
Technology
SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science &
Photographic Technology
GA 356SO
UT WOS:000259798100001
ER
PT J
AU Boudreau, J
Nelson, RF
Margolis, HA
Beaudoin, A
Guindon, L
Kimes, DS
AF Boudreau, Jonathan
Nelson, Ross F.
Margolis, Hank A.
Beaudoin, Andre
Guindon, Luc
Kimes, Daniel S.
TI Regional aboveground forest biomass using airborne and spaceborne LiDAR
in Quebec
SO REMOTE SENSING OF ENVIRONMENT
LA English
DT Article
DE biomass estimation; forest carbon stocks; Geoscience Laser Altimeter
System (GLAS); ICESat; LiDAR; portable airborne laser systems (PALS)
ID MULTIPLE RESOURCE INVENTORY; LASER ALTIMETER; CANOPY STRUCTURE;
FOOTPRINT LIDAR; BOREAL FOREST; TREE HEIGHT; RAIN-FOREST; LAND-COVER;
CARBON; TOPOGRAPHY
AB Aboveground dry biomass was estimated for the 1.3 M km(2) forested area south of the treeline in the eastern Canadian province of Quebec by combining data from an airborne and spaceborne LiDAR, a Landsat ETM+ land cover map, a Shuttle Radar Topographic Mission (SRTM) digital elevation model, ground inventory plots, and vegetation zone maps. Plot-level biomass was calculated using allometric relationships between tree attributes and biomass. A small footprint portable laser profiler then flew over these inventory plots to develop a generic airborne LiDAR-based biomass equation (R-2=0.65, n=207). The same airborne LiDAR system flew along four portions of orbits of the ICESat Geoscience Laser Altimeter System (GLAS). A square-root transformed equation was developed to predict airborne profiling LiDAR estimates of aboveground dry biomass from GLAS waveform parameters combined with an SRTM slope index (R-2=0.59, n = 1325). Using the 104,044 quality-filtered GLAS pulses obtained during autumn 2003 from 97 orbits over the study area, we then predicted aboveground dry biomass for the main vegetation areas of Quebec as well as for the entire Province south of the treeline. Including cover type covariances both within and between GLAS orbits increased standard errors of the estimates by two to five times at the vegetation zone level and as much as threefold at the provincial level. Aboveground biomass for the whole study area averaged 39.0 +/- 2.2 (standard error) Mg ha(-1) and totalled 4.9 +/- 0.3 Pg. Biomass distributions were 12.6% northern hardwoods, 12.6% northern mixedwood, 38.4% commercial boreal, 13% non-commercial boreal, 14.2% taiga, and 9.2% treed tundra. Non-commercial forests represented 36% of the estimated aboveground biomass, thus highlighting the importance of remote northern forests to C sequestration. This study has shown that space-based forest inventories of northern forests could be an efficient way of estimating the amount, distribution, and uncertainty of aboveground biomass and carbon stocks at large spatial scales. (c) 2008 Elsevier Inc. All rights reserved.
C1 [Nelson, Ross F.; Kimes, Daniel S.] NASA, Goddard Space Flight Ctr, Biospher Sci Branch, Greenbelt, MD 20771 USA.
[Boudreau, Jonathan; Margolis, Hank A.] Univ Laval, Fac Foresterie & Geomat, Ctr Etud Foret, Quebec City, PQ G1K 7P4, Canada.
[Beaudoin, Andre; Guindon, Luc] Canadian Forest Serv, Nat Resources Canada, Laurentian Forestry Ctr, Quebec City, PQ G1V 4C7, Canada.
RP Nelson, RF (reprint author), NASA, Goddard Space Flight Ctr, Biospher Sci Branch, Code 614-4, Greenbelt, MD 20771 USA.
EM Ross.F.Nelson@nasa.gov
RI Nelson, Ross/H-8266-2014
NR 53
TC 163
Z9 174
U1 7
U2 73
PU ELSEVIER SCIENCE INC
PI NEW YORK
PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA
SN 0034-4257
EI 1879-0704
J9 REMOTE SENS ENVIRON
JI Remote Sens. Environ.
PD OCT 15
PY 2008
VL 112
IS 10
BP 3876
EP 3890
DI 10.1016/j.rse.2008.06.003
PG 15
WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic
Technology
SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science &
Photographic Technology
GA 356SO
UT WOS:000259798100012
ER
PT J
AU Campbell, PKE
Middleton, EM
Corp, LA
Kim, MS
AF Campbell, P. K. Entcheva
Middleton, E. M.
Corp, L. A.
Kim, M. S.
TI Contribution of chlorophyll fluorescence to the apparent vegetation
reflectance
SO SCIENCE OF THE TOTAL ENVIRONMENT
LA English
DT Article; Proceedings Paper
CT 5th International Symposium on Ecosystem Behavior
CY JUN 25-30, 2006
CL Univ Calf Santa Cruz, Santa Cruz, CA
HO Univ Calf Santa Cruz
DE Chlorophyll fluorescence; Vegetation function/stress; Remote sensing;
Apparent vegetation reflectance; High resolution spectra
AB Current strategies for monitoring the physiologic status of terrestrial vegetation rely on remote sensing reflectance data, which provide estimates of vigor based primarily on chlorophyll content. Chlorophyll fluorescence (ChlF) measurements offer a non-destructive alternative and a more direct approach for diagnosis of vegetation stress before a significant reduction in chlorophyll content has occurred. Thus, technology based on ChlF may allow more accurate carbon sequestration estimates and earlier stress detection than is possible when using reflectance data alone. However, the observed apparent vegetation reflectance (Ra) in reality includes contributions from both the reflected and fluoresced radiation. The aim of this study is to determine the relative contributions of reflectance and ChlF fractions to Ra in the red to near-infrared region (650-800 nm) of the spectrum. The practical objectives of the study are to: 1) evaluate the relationship between ChlF and reflectance at the foliar level for corn, soybean and maple; and 2) for corn, determine if the relationship established for healthy vegetation changes under nitrogen (N) deficiency.
To obtain generally applicable results, experimental measurements were conducted on unrelated crop and tree species (corn, soybean and maple) under controlled conditions and a gradient of inorganic N fertilization levels. Optical reflectance spectra and actively induced ChlF emissions were collected on the same foliar samples, in conjunction with measurements of photosynthetic function, pigment levels, and carbon (C) and N content. The spectral trends were examined for similarities. On average, 10-20% of Ra at 685 nm was actually due to ChlF. The spectral trends in steady state and maximum fluorescence varied significantly, with steady state fluorescence (especially red, 685 nm) showing higher ability for species and treatment separation. The relative contribution of ChlF to Ra varied significantly among species, with maple emitting much higher fluorescence amounts, as compared to corn and soybean. Steady state fluorescence from individual red and far-red emission bands (F685 and F740, respectively) and their ratio consistently enabled species separation. For corn, the relative ChlF fraction increased in concert with the nutrient stress levels from <2% for non-stressed foliage to > 7% for severely N deficient plants. Steady state ChlF at 685 nm provided optimal N treatment separation. This study confirms the trends in the steady state red/far-red ratio (F685s/F740s) associated with N deficiency and vegetation stress, previously established using active single narrow band excitation. (C) 2007 Elsevier B.V. All rights reserved.
C1 [Campbell, P. K. Entcheva; Middleton, E. M.; Corp, L. A.] NASA, Goddard Space Flight Ctr, Hydrospher & Biospher Sci Lab, Biospher Sci Branch, Greenbelt, MD 20771 USA.
[Campbell, P. K. Entcheva] UMBC, Joint Ctr Earth Syst Technol, Catonsville, MD 21228 USA.
[Corp, L. A.; Kim, M. S.] ARS, USDA, Beltsville, MD 20705 USA.
RP Campbell, PKE (reprint author), NASA, Goddard Space Flight Ctr, Hydrospher & Biospher Sci Lab, Biospher Sci Branch, Code 614-4,Bldg 33, Greenbelt, MD 20771 USA.
EM pcampbel@pop900.gsfc.nasa.gov
RI Campbell, Petya/G-4931-2013; Campbell, Petya/L-7486-2013
OI Campbell, Petya/0000-0002-0505-4951; Campbell, Petya/0000-0002-0505-4951
NR 19
TC 47
Z9 49
U1 2
U2 21
PU ELSEVIER SCIENCE BV
PI AMSTERDAM
PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS
SN 0048-9697
J9 SCI TOTAL ENVIRON
JI Sci. Total Environ.
PD OCT 15
PY 2008
VL 404
IS 2-3
SI SI
BP 433
EP 439
DI 10.1016/j.scitotenv.2007.11.004
PG 7
WC Environmental Sciences
SC Environmental Sciences & Ecology
GA 369NT
UT WOS:000260701900024
PM 18164750
ER
PT J
AU Keller, HU
Goetz, W
Hartwig, H
Hviid, SF
Kramm, R
Markiewicz, WJ
Reynolds, R
Shinohara, C
Smith, P
Tanner, R
Woida, P
Woida, R
Bos, BJ
Lemmon, MT
AF Keller, H. U.
Goetz, W.
Hartwig, H.
Hviid, S. F.
Kramm, R.
Markiewicz, W. J.
Reynolds, R.
Shinohara, C.
Smith, P.
Tanner, R.
Woida, P.
Woida, R.
Bos, B. J.
Lemmon, M. T.
TI Phoenix Robotic Arm Camera
SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS
LA English
DT Article
ID MARS PATHFINDER; IMAGER; SURFACE; ICE
AB The Phoenix Robotic Arm Camera (RAC) is a variable-focus color camera mounted to the Robotic Arm (RA) of the Phoenix Mars Lander. It is designed to acquire both close-up images of the Martian surface and microscopic images (down to a scale of 23 mm/pixel) of material collected in the RA scoop. The mounting position at the end of the Robotic Arm allows the RAC to be actively positioned for imaging of targets not easily seen by the Stereo Surface Imager (SSI), such as excavated trench walls and targets under the Lander structure. Color information is acquired by illuminating the target with red, green, and blue light-emitting diodes. Digital terrain models (DTM) can be generated from RAC images acquired from different view points. This can provide high-resolution stereo information about fine details of the trench walls. The large stereo baseline possible with the arm can also provide a far-field DTM. The primary science objectives of the RAC are the search for subsurface soil/ice layering at the landing site and the characterization of scoop samples prior to delivery to other instruments on board Phoenix. The RAC shall also provide low-resolution panoramas in support of SSI activities and acquire images of the Lander deck for instrument and Lander check out. The camera design was inherited from the unsuccessful Mars Polar Lander mission (1999) and further developed for the (canceled) Mars Surveyor 2001 Lander (MSL01). Extensive testing and partial recalibration qualified the MSL01 RAC flight model for integration into the Phoenix science payload.
C1 [Keller, H. U.; Goetz, W.; Hartwig, H.; Hviid, S. F.; Kramm, R.; Markiewicz, W. J.] Max Planck Inst Sonnensyst Forsch, D-37191 Katlenburg Lindau, Germany.
[Reynolds, R.; Shinohara, C.; Smith, P.; Tanner, R.; Woida, P.; Woida, R.] Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA.
[Bos, B. J.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
[Lemmon, M. T.] Texas A&M Univ, Dept Atmospher Sci, College Stn, TX 77843 USA.
RP Keller, HU (reprint author), Max Planck Inst Sonnensyst Forsch, Max Planck Str 2, D-37191 Katlenburg Lindau, Germany.
EM markiewicz@mps.mpg.de
RI Lemmon, Mark/E-9983-2010
OI Lemmon, Mark/0000-0002-4504-5136
FU Deutsches Zentrum fur Luft- und Raumfahrt e.V. (DLR) [50 QM 0602]
FX This research was supported in part by Deutsches Zentrum fur Luft- und
Raumfahrt e.V. (DLR) grant 50 QM 0602. The valuable reviews by Ken
Herkenhoff, USGS, Flagstaff, Arizona, Untied States, and by an anonymous
reviewer are gratefully acknowledged.
NR 18
TC 16
Z9 16
U1 1
U2 5
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 2169-9097
J9 J GEOPHYS RES-PLANET
JI J. Geophys. Res.-Planets
PD OCT 14
PY 2008
VL 113
AR E00A17
DI 10.1029/2007JE003044
PG 15
WC Geochemistry & Geophysics
SC Geochemistry & Geophysics
GA 362DX
UT WOS:000260179500001
ER
PT J
AU Biris, AR
Dan, LP
Dervishi, E
Li, ZR
Xu, Y
Trigwell, S
Misan, I
Biris, AS
AF Biris, Alexandru R.
Dan Lupu
Dervishi, Enkeleda
Li, Zhongrui
Xu, Yang
Trigwell, Steve
Misan, Ioan
Biris, Alexandru S.
TI Multiwall carbon nanotubes synthesized by RF-CCVD on novel CaO supported
catalysts
SO PHYSICS LETTERS A
LA English
DT Article
DE Catalysis; CaO; Carbon nanotubes
ID QUALITY
AB Muldwall carbon nanotubes were synthesized on the FeCoCaO and FeMoCaO catalysts by RF-CCVD at 750 degrees C, 850 degrees C and 950 degrees C, using acetylene as the carbon source. Analytically, it was found that the nanotubes are well crystallized, with outside diameters ranging between 10 and 60 nm and a ratio of the outside to the inside diameters of 2 to 3. The nanotubes did not present amorphous carbon and their purity increased with the temperature of synthesis. A relatively large number of metallic nanoparticles of various dimensions and shapes encapsulated inside the nanotubes were observed by TEM in most of the nanotube samples. (C) 2008 Elsevier B.V. All rights reserved.
C1 [Dervishi, Enkeleda; Li, Zhongrui; Xu, Yang; Biris, Alexandru S.] Univ Arkansas, Nanotechnol Ctr, Dept Appl Sci, Little Rock, AR 72204 USA.
[Biris, Alexandru R.; Dan Lupu; Misan, Ioan] Natl Inst Isotop & Mol Technol, R-400293 Cluj Napoca, Romania.
[Trigwell, Steve] NASA, ASRC, Kennedy Space Ctr, FL 32899 USA.
RP Biris, AS (reprint author), Univ Arkansas, Nanotechnol Ctr, Dept Appl Sci, Little Rock, AR 72204 USA.
EM asbiris@ualr.edu
RI Biris, Alexandru/A-8507-2010; Dervishi, Enkeleda/B-2239-2010; Biris,
Alexandru /C-4517-2011
NR 9
TC 8
Z9 8
U1 0
U2 6
PU ELSEVIER SCIENCE BV
PI AMSTERDAM
PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS
SN 0375-9601
J9 PHYS LETT A
JI Phys. Lett. A
PD OCT 13
PY 2008
VL 372
IS 42
BP 6416
EP 6419
DI 10.1016/j.physleta.2008.08.030
PG 4
WC Physics, Multidisciplinary
SC Physics
GA 368XJ
UT WOS:000260656200020
ER
PT J
AU Li, JLF
Waliser, D
Woods, C
Teixeira, J
Bacmeister, J
Chern, J
Shen, BW
Tompkins, AM
Tao, WK
Kohler, M
AF Li, Jui-Lin F.
Waliser, D.
Woods, C.
Teixeira, J.
Bacmeister, J.
Chern, J.
Shen, B. -W
Tompkins, A. M.
Tao, W. -K
Kohler, M.
TI Comparisons of satellites liquid water estimates to ECMWF and GMAO
analyses, 20th century IPCC AR4 climate simulations, and GCM simulations
SO GEOPHYSICAL RESEARCH LETTERS
LA English
DT Article
ID CLOUDS
AB To assess the fidelity of general circulation models (GCMs) in simulating cloud liquid water, liquid water path (LWP) retrievals from several satellites with passive sensors and the vertically-resolved liquid water content (LWC) from the CloudSat are used. Comparisons are made with ECMWF and MERRA analyses, GCM simulations utilized in the IPCC 4th Assessment, and three GCM simulations. There is considerable disagreement amongst the LWP estimates and amongst the modeled values. The LWP from GCMs are much larger than the observed estimates and the two analyses. The largest values in the CloudSat LWP occur over the boundary-layer stratocumulus regions; this feature is not as evident in the analyses or models. Better agreement is found between the two analyses and CloudSat LWP when cases with surface precipitation are excluded. The upward vertical extent of LWC from the GCMs and analyses is greater than CloudSat estimates. The issues of representing LWC and precipitation consistently between satellite-derived and model values are discussed.
C1 [Li, Jui-Lin F.; Waliser, D.; Woods, C.; Teixeira, J.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[Bacmeister, J.; Chern, J.; Shen, B. -W; Tao, W. -K] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
[Tompkins, A. M.; Kohler, M.] European Ctr Medium Range Weather Forecasts, Reading RG2 9AX, Berks, England.
RP Li, JLF (reprint author), CALTECH, Jet Prop Lab, Mail Stop 183-601, Pasadena, CA 91109 USA.
EM jli@jpl.nasa.gov
RI Tompkins, Adrian/N-6472-2013
OI Tompkins, Adrian/0000-0003-0975-6691
FU JPL; California Institute of Technology; NASA
FX The research was carried out at the JPL, California Institute of
Technology, under a contract with NASA.
NR 8
TC 31
Z9 31
U1 2
U2 9
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0094-8276
EI 1944-8007
J9 GEOPHYS RES LETT
JI Geophys. Res. Lett.
PD OCT 11
PY 2008
VL 35
IS 19
AR L19710
DI 10.1029/2008GL035427
PG 6
WC Geosciences, Multidisciplinary
SC Geology
GA 359LH
UT WOS:000259987700006
ER
PT J
AU Hosokawa, K
Taguchi, S
Suzuki, S
Collier, MR
Moore, TE
Thomsen, MF
AF Hosokawa, K.
Taguchi, S.
Suzuki, S.
Collier, M. R.
Moore, T. E.
Thomsen, M. F.
TI Estimation of magnetopause motion from low-energy neutral atom emission
SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
LA English
DT Article
ID SOLAR-WIND CONDITIONS; SUBSOLAR ENA JET; GEOSYNCHRONOUS ORBIT; EARTHS
MAGNETOPAUSE; PLASMA OBSERVATIONS; BOW SHOCK; FIELD; SHAPE; MARS;
CROSSINGS
AB A new method for deriving the position of the dayside equatorial magnetopause directly from the measured intensity of energetic neutral atom (ENA) emissions is presented. This approach makes it possible to track the position of the magnetopause using data observed by the low-energy neutral atom (LENA) imager on board the Imager for Magnetopause-to-Aurora Global Exploration (IMAGE) spacecraft. The model is applied to data recorded during a period of high solar wind dynamic pressure on 13 April 2001. In this interval, significant ENA flux was observed originating from the dayside low-latitude magnetosheath. This ENA flux is primarily the result of enhanced charge exchange between the increased solar wind plasma and exospheric hydrogen neutrals. The temporal variation in the estimated magnetopause position is compared with in situ measurements of magnetopause crossings by the LANL-01A spacecraft in geosynchronous orbit and the results of a recent empirical magnetopause model. It is demonstrated that the subsolar distance of the magnetopause was successfully tracked for a period of more than 1 h. In this particular case example, the dayside magnetopause is closer to the Earth and fluctuates on a shorter timescale than predicted by the previous empirical model based on in situ data. It is also revealed that the subsolar magnetopause can move with speeds of 100-200 km s(-1) in response to marked dynamic pressure changes, and during periods of stable dynamic pressure can fluctuates with speeds of up to 50 km s(-1).
C1 [Hosokawa, K.; Taguchi, S.; Suzuki, S.] Univ Electrocommun, Dept Informat & Commun Engn, Tokyo 1828585, Japan.
[Collier, M. R.; Moore, T. E.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
[Thomsen, M. F.] Los Alamos Natl Lab, Los Alamos, NM USA.
RP Hosokawa, K (reprint author), Univ Electrocommun, Dept Informat & Commun Engn, 1-5-1 Chofugaoka, Tokyo 1828585, Japan.
EM hosokawa@ice.uec.ac.jp; taguchi@ice.uec.ac.jp; shin.s@ice.uec.ac.jp;
michael.r.collier@nasa.gov; tmoore@pop600.gsfc.nasa.gov;
mthomsen@lanl.gov
RI Moore, Thomas/D-4675-2012; Collier, Michael/I-4864-2013
OI Moore, Thomas/0000-0002-3150-1137; Collier, Michael/0000-0001-9658-6605
FU Japan Society for the Promotion of Science [18540443]; Goddard Space
Flight Center [UPN 370-28-20]
FX This research was supported by a Grant-in-Aid (18540443, Category C)
from the Japan Society for the Promotion of Science, and by the IMAGE
project (UPN 370-28-20) at the Goddard Space Flight Center. The authors
wish to thank N. Ness at the Bartol Research Institute for access to
data from the MFI and SWE instruments on board the ACE spacecraft.
NR 31
TC 7
Z9 7
U1 0
U2 1
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0148-0227
J9 J GEOPHYS RES-SPACE
JI J. Geophys. Res-Space Phys.
PD OCT 11
PY 2008
VL 113
IS A10
AR A10205
DI 10.1029/2008JA013124
PG 11
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 359MU
UT WOS:000259992000002
ER
PT J
AU Esposito, P
Israel, GL
Zane, S
Senziani, F
Starling, RLC
Rea, N
Palmer, DM
Gehrels, N
Tiengo, A
De Luca, A
Gotz, D
Mereghetti, S
Romano, P
Sakamoto, T
Barthelmy, SD
Stella, L
Turolla, R
Feroci, M
Mangano, V
AF Esposito, P.
Israel, G. L.
Zane, S.
Senziani, F.
Starling, R. L. C.
Rea, N.
Palmer, D. M.
Gehrels, N.
Tiengo, A.
De Luca, A.
Goetz, D.
Mereghetti, S.
Romano, P.
Sakamoto, T.
Barthelmy, S. D.
Stella, L.
Turolla, R.
Feroci, M.
Mangano, V.
TI The 2008 May burst activation of SGR 1627-41
SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
LA English
DT Article
DE stars: neutron; X-rays: bursts; X-rays: individual: SGR 1627-41
ID SOFT GAMMA REPEATER; X-RAY-EMISSION; LOCALIZATION; SGR-1900+14; PULSARS;
HETE-2
AB In 2008 May, the soft gamma-ray repeater (SGR) SGR 1627-41 resumed its bursting activity after nearly a decade of quiescence. After detection of a bright burst, Swift pointed its X-ray telescope in the direction of the source in less than five hours and followed it for over five weeks. In this Letter, we present an analysis of the data from these Swift observations and an XMM-Newton one performed when SGR 1627-41 was still in a quiescent state. The analysis of the bursts detected with Swift/Burst Alert Telescope shows that their temporal and spectral properties are similar to those found in previous observations of SGR 1627-41 and other SGRs. The maximum peak luminosity of the bursts was similar to 2 x 10(41) erg s(-1). Our data show that the outburst was accompanied by a fast flux enhancement and by a hardening of the spectrum with respect to the persistent emission.
C1 [Esposito, P.; De Luca, A.] Univ Pavia, Dipartimento Fis Nucl & Teor, I-27100 Pavia, Italy.
[Esposito, P.; De Luca, A.] Univ Pavia, INFN Pavia, I-27100 Pavia, Italy.
[Esposito, P.; Senziani, F.; Tiengo, A.; De Luca, A.; Mereghetti, S.] INAF Ist Astrofis Spaziale & Fis Cosm Milano, I-20133 Milan, Italy.
[Israel, G. L.; Stella, L.] Osserv Astron Roma, INAF, I-00040 Monte Porzio Catone, Italy.
[Zane, S.; Turolla, R.] Univ Coll London, Mullard Space Sci Lab, Dorking RH5 6NT, Surrey, England.
[Senziani, F.] IUSS, I-27100 Pavia, Italy.
[Starling, R. L. C.] Univ Leicester, Dept Phys & Astron, Leicester LE1 7RH, Leics, England.
[Rea, N.] Univ Amsterdam, Astron Inst Anton Pannekoek, NL-1098 SJ Amsterdam, Netherlands.
[Palmer, D. M.; Sakamoto, T.; Barthelmy, S. D.] Los Alamos Natl Lab, Los Alamos, NM 87545 USA.
[Gehrels, N.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
[Goetz, D.] CEA Saclay, DSM Irfu Serv Astrophys, F-91191 Gif Sur Yvette, France.
[Romano, P.; Mangano, V.] INAF Ist Astrofis Spaziale & Fis Cosm Palermo, I-90146 Palermo, Italy.
[Turolla, R.] Univ Padua, Dipartimento Fis, I-35131 Padua, Italy.
[Feroci, M.] INAF Ist Astrofis Spaziale & Fis Cosm Roma, I-00133 Rome, Italy.
RP Esposito, P (reprint author), Univ Pavia, Dipartimento Fis Nucl & Teor, Via A Bassi 6, I-27100 Pavia, Italy.
EM paoloesp@iasf-milano.inaf.it
RI Barthelmy, Scott/D-2943-2012; Gehrels, Neil/D-2971-2012; Rea,
Nanda/I-2853-2015;
OI Rea, Nanda/0000-0003-2177-6388; Tiengo, Andrea/0000-0002-6038-1090;
Feroci, Marco/0000-0002-7617-3421; MEREGHETTI,
SANDRO/0000-0003-3259-7801; Israel, GianLuca/0000-0001-5480-6438; De
Luca, Andrea/0000-0001-6739-687X; Esposito, Paolo/0000-0003-4849-5092
FU ASI/INAF [I/088/06/0, AAE TH-058]; STFC; NWO Veni; CNES
FX This research is based on observations with the NASA/UK/ASI Swift
mission. We thank the Swift duty scientists and science planners for
making these observations possible. We also used data obtained with
XMM-Newton, an ESA science mission with instruments and contributions
directly funded by ESA Member States and NASA. The Italian authors
acknowledge the partial support from ASI (ASI/INAF contracts I/088/06/0
and AAE TH-058). SZ and RLCS acknowledge support from STFC. NR is
supported by an NWO Veni Fellowship. DG acknowledges the CNES for
financial support.
NR 32
TC 34
Z9 34
U1 0
U2 1
PU OXFORD UNIV PRESS
PI OXFORD
PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND
SN 0035-8711
EI 1365-2966
J9 MON NOT R ASTRON SOC
JI Mon. Not. Roy. Astron. Soc.
PD OCT 11
PY 2008
VL 390
IS 1
BP L34
EP L38
DI 10.1111/j.1745-3933.2008.00530.x
PG 5
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 367BZ
UT WOS:000260528800008
ER
PT J
AU Larruquert, JI
Keski-Kuha, RAM
AF Larruquert, Juan I.
Keski-Kuha, Ritva A. M.
TI Removal of a protective coating on Al by ion etching for high
reflectance in the far ultraviolet
SO APPLIED OPTICS
LA English
DT Article
ID X-RAY MIRRORS; ALUMINUM FILMS; VACUUM-ULTRAVIOLET; OPTICAL-CONSTANTS;
EVAPORATED ALUMINUM; REFLECTIVITY; SURFACE; ENHANCEMENT; DEGRADATION;
MULTILAYERS
AB The effect of ion etching on the reflectance of Al coatings in the far ultraviolet is iuvestigated. Ion etching of an overlayer grown on Al was performed by applying 100-300 eV Ar+ ions using an ion gun. Ion etching was employed to remove the oxide naturally grown on an Al film that had been in contact with atmosphere. 101) etching was also used to remove part or all of the protective MgF2 film on Al. The reflectance at 121.6 nm, H Lyman alpha line of the overlayer-removed Al surface was monitored after protecting it with a MgF2 layer. Ion etching on both types of coatings resulted in an excellent reflectance value at 121.6 nm, whereas a reflectance loss was observed at longer wavelengths. (C) 2008 Optical Society of America
C1 [Larruquert, Juan I.] CSIC, Grp Opt Laminas Delgadas, Inst Fis Aplicada, Madrid 28006, Spain.
[Keski-Kuha, Ritva A. M.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
RP Larruquert, JI (reprint author), CSIC, Grp Opt Laminas Delgadas, Inst Fis Aplicada, C Seranno 144, Madrid 28006, Spain.
EM larruquert@ifa.cetef.csic.es
OI Larruquert, Juan/0000-0001-6356-9702
FU NASA Office of Space Science [RTOP 344-01-23]; Spanish National
Programme for Space Research; Subdireccion General de Proyectos de
Investigacion; Ministerio de Ciencia y Tecnologia [ESP2005-02650]
FX This research was supported by NASA Office of Space Science grant RTOP
344-01-23 and by the Spanish National Programme for Space Research,
Subdireccion General de Proyectos de Investigacion, Ministerio de
Ciencia y Tecnologia, project ESP2005-02650. The experimental work was
performed while Juan I. Larruquert held a National Research
Council-NASA/Goddard Space Flight Center Research Associateship.
NR 32
TC 1
Z9 1
U1 1
U2 8
PU OPTICAL SOC AMER
PI WASHINGTON
PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA
SN 1559-128X
EI 2155-3165
J9 APPL OPTICS
JI Appl. Optics
PD OCT 10
PY 2008
VL 47
IS 29
BP 5253
EP 5260
DI 10.1364/AO.47.005253
PG 8
WC Optics
SC Optics
GA 368AN
UT WOS:000260593800003
PM 18846163
ER
PT J
AU Refaat, TF
Ismail, S
Abedin, MN
Spuler, SM
Mayor, SD
Singh, UN
AF Refaat, Tamer F.
Ismail, Syed
Abedin, M. Nurul
Spuler, Scott M.
Mayor, Shane D.
Singh, Upendra N.
TI Lidar backscatter signal recovery from phototransistor systematic effect
by deconvolution
SO APPLIED OPTICS
LA English
DT Article
ID ALGAASSB/INGAASSB PHOTOTRANSISTORS; MU-M; RESOLUTION; AEROSOLS; RANGE;
LASER
AB Backscatter lidar detection systems have been designed and integrated at NASA Langley Research Center Using IR heterojunction phototransistors. The design focused oil maximizing the system signal-to-noise ratio rather than noise minimization. The detection systems have been validated Using the Raman-shifted eye-safe aerosol lidar (REAL) at the National Center for Atmospheric Research. Incorporating such devices introduces sonic systematic effects in the form of blurring to the backscattered signals. Characterization of the detection system transfer function aided in recovering such effects by deconvolution. The transfer function was obtained by measuring and fitting the system impulse response using single-pole approximation. An iterative deconvolution algorithm was implemented in order to recover the system resolution, while maintaining high signal-to-noise ratio. Results indicated a full recovery of the lidar signal, with resolution matching avalanche photodiodes. Application of such a technique to atmospheric boundary and cloud layers data restores the range resolution, up to 60m, and overcomes the blurring effects. (C) 2008 Optical Society of America
C1 [Refaat, Tamer F.] Old Dominion Univ, Appl Res Ctr, Newport News, VA 23606 USA.
[Ismail, Syed] NASA, Langley Res Ctr, Chem & Dynam Branch, Hampton, VA 23681 USA.
[Abedin, M. Nurul] NASA, Langley Res Ctr, Remote Sensing Flight Syst Branch, Hampton, VA 23681 USA.
[Spuler, Scott M.; Mayor, Shane D.] Natl Ctr Atmospher Res, Atmospher Technol Div, Boulder, CO 80307 USA.
[Singh, Upendra N.] NASA, Langley Res Ctr, Syst Engn Directorate, Hampton, VA 23681 USA.
RP Refaat, TF (reprint author), Old Dominion Univ, Appl Res Ctr, 12050 Jefferson Ave, Newport News, VA 23606 USA.
EM trefaat@jlab.org
NR 33
TC 1
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U1 2
U2 2
PU OPTICAL SOC AMER
PI WASHINGTON
PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA
SN 1559-128X
EI 2155-3165
J9 APPL OPTICS
JI Appl. Optics
PD OCT 10
PY 2008
VL 47
IS 29
BP 5281
EP 5295
DI 10.1364/AO.47.005281
PG 15
WC Optics
SC Optics
GA 368AN
UT WOS:000260593800006
PM 18846166
ER
PT J
AU Zhu, W
Kaspi, VM
Dib, R
Woods, PM
Gavriil, FP
Archibald, AM
AF Zhu, Weiwei
Kaspi, Victoria M.
Dib, Rim
Woods, Peter M.
Gavriil, Fotis P.
Archibald, Anne M.
TI The long-term radiative evolution of anomalous X-ray pulsar 1E 2259+586
after its 2002 outburst
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE pulsars : individual (1E 2259+586); stars : neutron; X-rays : stars
ID XMM-NEWTON OBSERVATIONS; PHOTON IMAGING CAMERA; XTE J1810-197; 1RXS
J170849.0-400910; TRANSIENT MAGNETAR; 1E-1048.1-5937; BURSTS;
VARIABILITY; EMISSION; XTE-J1810-197
AB We present an analysis of five XMM-Newton observations of the anomalous X-ray pulsar (AXP) 1E 2259+586 taken in 2004 and 2005 during its relaxation following its 2002 outburst. We compare these data with those of five previous XMM-Newton observations taken in 2002 and 2003, and find the observed flux decay is well described by a power law of index -0.69 +/- 0.03. As of mid-2005, the source may still have been brighter than preoutburst, and was certainly hotter. We find a strong correlation between hardness and flux, as seen in other AXPs. We discuss the implications of these results for the magnetar model.
C1 [Zhu, Weiwei; Kaspi, Victoria M.; Dib, Rim; Archibald, Anne M.] McGill Univ, Dept Phys, Montreal, PQ H3A 2T8, Canada.
[Woods, Peter M.] Dynetics Inc, Huntsville, AL 35806 USA.
[Woods, Peter M.] NSSTC, Huntsville, AL 35805 USA.
[Gavriil, Fotis P.] NASA, Goddard Space Flight Ctr, Astrophys Sci Div, Greenbelt, MD 20771 USA.
[Gavriil, Fotis P.] Univ Maryland Baltimore Cty, Ctr Res & Explorat Space Sci & Technol, Baltimore, MD 21250 USA.
RP Zhu, W (reprint author), McGill Univ, Dept Phys, 3600 Univ St, Montreal, PQ H3A 2T8, Canada.
EM zhuww@physics.mcgill.ca; vkaspi@physics.mcgill.ca;
rim@physics.mcgill.ca; aarchiba@physics.mcgill.ca
FU NSERC Discovery grant Rgpin [228738-03]; R. Howard Webster Fellowship;
Canadian Institute for Advanced Research; Les Fonds de la Recherche sur
la Nature et les Technologies; Canada Research Chair; Lorne Trottier
Chair in Astrophysics and Cosmology; NSERC PGSD scholarship
FX We thank A. Beloborodov, A. Cumming, and G. Vasisht for useful
discussions. Support for this work was provided by an NSERC Discovery
grant Rgpin 228738-03, an R. Howard Webster Fellowship of the Canadian
Institute for Advanced Research, Les Fonds de la Recherche sur la Nature
et les Technologies, a Canada Research Chair, and the Lorne Trottier
Chair in Astrophysics and Cosmology to V. M. K. R. D. was supported by
an NSERC PGSD scholarship.
NR 47
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U1 0
U2 4
PU IOP PUBLISHING LTD
PI BRISTOL
PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND
SN 0004-637X
EI 1538-4357
J9 ASTROPHYS J
JI Astrophys. J.
PD OCT 10
PY 2008
VL 686
IS 1
BP 520
EP 527
DI 10.1086/591219
PG 8
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 357BV
UT WOS:000259822200042
ER
PT J
AU Looper, DL
Kirkpatrick, JD
Cutri, RM
Barman, T
Burgasser, AJ
Cushing, MC
Roellig, T
McGovern, MR
McLean, IS
Rice, E
Swift, BJ
Schurr, SD
AF Looper, Dagny L.
Kirkpatrick, J. Davy
Cutri, Roc M.
Barman, Travis
Burgasser, Adam J.
Cushing, Michael C.
Roellig, Thomas
McGovern, Mark R.
McLean, Ian S.
Rice, Emily
Swift, Brandon J.
Schurr, Steven D.
TI Discovery of two nearby peculiar L dwarfs from the 2MASS proper-motion
survey: Young or metal-rich?
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE stars : individual (2MASS J18212815+1414010, 2MASS J21481628+4003593);
stars : low-mass, brown dwarfs; techniques : spectroscopic
ID ALL-SKY SURVEY; SPITZER-SPACE-TELESCOPE; KECK-II-TELESCOPE; SPECTRAL
TYPE-L; ULTRACOOL DWARFS; INFRARED SPECTRA; COOL NEIGHBORS; BROWN
DWARFS; T-DWARFS; SPECTROPHOTOMETRIC STANDARDS
AB We present the discovery of two nearby L dwarfs from our 2MASS proper-motion search, which uses multiepoch 2MASS observations covering similar to 4700 deg(2) of sky. 2MASS J18212815+1414010 and 2MASS J21481628+4003593 were overlooked by earlier surveys due to their faint optical magnitudes and their proximity to the Galactic plane (10 degrees <= |b| <= 15 degrees). Assuming that both dwarfs are single, we derive spectrophotometric distances of similar to 10 pc, thus increasing the number of known L dwarfs within 10 pc to 10. In the near-infrared, 2MASS J21481628+4003593 shows a triangular H-band spectrum, strong CO absorption, and a markedly red J-K-S color (2.38 +/- 0.06) for its L6 optical spectral type. 2MASS J18212815+1414010 also shows a triangular H-band spectrum and a slightly red J-K-S color (1.78 +/- 0.05) for its L4.5 optical spectral type. Both objects show strong silicate absorption at 9-11 mu m. Cumulatively, these features imply an unusually dusty photosphere for both of these objects. We examine several scenarios to explain the underlying cause for their enhanced dust content and find that a metal-rich atmosphere or a low surface gravity are consistent with these results. 2MASS J18212815+1414010 may be young (and therefore have a low surface gravity) based on its low tangential velocity of 10 km s(-1). On the other hand, 2MASS J21481628+4003593 has a high tangential velocity of 62 km s(-1) and is therefore likely old. Hence, high metallicity and low surface gravity may lead to similar effects.
C1 [Looper, Dagny L.; Cushing, Michael C.] Univ Hawaii, Inst Astron, Honolulu, HI 96822 USA.
[Kirkpatrick, J. Davy; Cutri, Roc M.; Schurr, Steven D.] CALTECH, Ctr Infrared Proc & Anal, Pasadena, CA 91125 USA.
[Barman, Travis] Lowell Observ, Flagstaff, AZ 86001 USA.
[Burgasser, Adam J.] MIT, Kavli Inst Astrophys & Space Res, Cambridge, MA 02139 USA.
[Cushing, Michael C.; Swift, Brandon J.] Univ Arizona, Steward Observ, Tucson, AZ 85721 USA.
[Roellig, Thomas] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
[McGovern, Mark R.] Antelope Valley Coll, Lancaster, CA 93536 USA.
[McLean, Ian S.; Rice, Emily] Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA.
RP Looper, DL (reprint author), Univ Hawaii, Inst Astron, 2680 Woodlawn Dr, Honolulu, HI 96822 USA.
RI Rice, Emily/G-4446-2013
OI Rice, Emily/0000-0002-3252-5886
FU Northrop Grumman Corporation; IPAC; University of Massachusetts;
Infrared Processing and Analysis Center/California Institute of
Technology; National Aeronautics and Space Administration; National
Science Foundation; W. M. Keck Foundation
FX We thank our referee, Nigel Hambly, for a timely and helpful report. We
would like to thank our Keck observing assistants Steven Magee and Julie
Rivera and our IRTF observing assistants Paul Sears and Dave Griep for
providing expert operation of the telescopes during our runs. We thank
our instrument scientists Jim Lyke and Grant Hill at Keck and Bobby Bus
and John Rayner at IRTF for their expertise in running the
spectrographs, imagers, and reduction software packages. We thank
Takashi Hattori for providing instrument support at Subaru. We would
like to thank John Stauffer and Maria Morales-Calderon for giving us
some telescope time in exchange for instrument expertise on 2005
December 9 (UT) at Keck II. D. L. L. thanks John Rayner for advising her
on part of this project and Dave Sanders for financial support. We are
grateful to Lee Rottler for assistance with setting up the REDSPEC
package at IPAC. This paper uses data from the Brown Dwarf Spectroscopic
Survey Archive (http://www.astro.ucla.edu/~mclean/BDSSarchive), the IRTF
Spectral Library
(http://irtfweb.ifa.hawaii.edu/~spex/spexlibrary/IRTFlibrary.html), the
SpeX Prism Library
(http://web.mit.edu/ajb/www/browndwarfs/spexprism/index.html), and
http://DwarfArchives.org. D. L. L. would like to thank the Northrop
Grumman Corporation for a small grant to IPAC, which paid for partial
salary support during the search phase of this project. This publication
also makes use of data products from the Two Micron All Sky Survey
(2MASS), which is a joint project of the University of Massachusetts and
the Infrared Processing and Analysis Center/California Institute of
Technology, funded by the National Aeronautics and Space Administration
and the National Science Foundation. D. L. L. is a guest user of the
Canadian Astronomy Data Centre, which is operated by the Herzberg
Institute of Astrophysics, National Research Council of Canada. This
research has also made use of the NASA/IPAC Infrared Science Archive
(IRSA), which is operated by the Jet Propulsion Laboratory, California
Institute of Technology, under contract with the National Aeronautics
and Space Administration. The 2006 August 4 UT NIRSPEC data were
obtained at the W. M. Keck Observatory from telescope time allocated to
the National Aeronautics and Space Administration through the agency's
scientific partnership with the California Institute of Technology and
the University of California. The Observatory was made possible by the
generous financial support of the W. M. Keck Foundation. As all
spectroscopic and imaging follow-up data were obtained from the summit
of Mauna Kea, the authors wish to recognize and acknowledge the very
significant cultural role and reverence that this mountaintop has always
had within the indigenous Hawaiian community. We are most fortunate to
have the opportunity to conduct observations there.
NR 59
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PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD OCT 10
PY 2008
VL 686
IS 1
BP 528
EP 541
DI 10.1086/591025
PG 14
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 357BV
UT WOS:000259822200043
ER
PT J
AU Stark, CC
Kuchner, MJ
AF Stark, Christopher C.
Kuchner, Marc J.
TI The detectability of exo-Earths and super-Earths via resonant signatures
in exozodiacal clouds
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE catalogs; circumstellar matter; infrared : stars; interplanetary medium;
methods : n-body simulations; planetary systems
ID SOLAR-SYSTEM; DUST RING; CLOSE ENCOUNTERS; EPSILON-ERIDANI; DEBRIS
DISKS; KUIPER-BELT; PLANETS; COBE; MIGRATION; CAPTURE
AB Directly imaging extrasolar terrestrial planets necessarily means contending with the astrophysical noise of exozodiacal dust and the resonant structures created by these planets in exozodiacal clouds. Using a custom-tailored hybrid symplectic integrator, we have constructed 120 models of resonant structures created by exo-Earths and super-Earths on circular orbits interacting with collisionless steady-state dust clouds around a Sun-like star. Our models include enough particles to overcome the limitations of previous simulations that were often dominated by a handful of long-lived particles, allowing us to quantitatively study the contrast of the resulting ring structures. We found that in the case of a planet on a circular orbit, for a given star and dust source distribution, the morphology and contrast of the resonant structures depend on only two parameters: planet mass and a(p)(1/2)/beta, where a(p) is the planet's semimajor axis and beta is the ratio of radiation pressure force to gravitational force on a grain. We constructed multiparticle-sized models of 25,000 particles each and showed that in a collisionless cloud, a Dohnanyi crushing law yields a resonant ring whose optical depth is dominated by the largest grains in the distribution, not the smallest. We used these models to estimate the mass of the lowest mass planet that can be detected through observations of a resonant ring for a variety of assumptions about the dust cloud and the planet's orbit. Our simulations suggest that planets with mass as small as a few times Mar's mass may produce detectable signatures in debris disks at a(p)less than or similar to 10 AU.
C1 [Stark, Christopher C.] Univ Maryland, Dept Phys, College Pk, MD 20742 USA.
[Kuchner, Marc J.] NASA, Goddard Space Flight Ctr, Exoplanets & Stellar Astrophys Lab, Greenbelt, MD 20771 USA.
RP Stark, CC (reprint author), Univ Maryland, Dept Phys, Box 197,082 Regents Dr, College Pk, MD 20742 USA.
EM starkc@umd.edu
RI Kuchner, Marc/E-2288-2012
FU National Aeronautics and Space Administration and Goddard Space Flight
Center; Graduate Student Researchers Program; Harvard-Smithsonian Center
for Astrophysics; Keck Interferometer Nuller Shared Risk Science Program
FX We would like to thank the National Aeronautics and Space Administration
and Goddard Space Flight Center for support of this research through
funding from the Graduate Student Researchers Program, and the
Harvard-Smithsonian Center for Astrophysics and NASA's Navigator Program
for their financial support via the Keck Interferometer Nuller Shared
Risk Science Program.
NR 41
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PU IOP PUBLISHING LTD
PI BRISTOL
PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND
SN 0004-637X
EI 1538-4357
J9 ASTROPHYS J
JI Astrophys. J.
PD OCT 10
PY 2008
VL 686
IS 1
BP 637
EP 648
DI 10.1086/591442
PG 12
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 357BV
UT WOS:000259822200051
ER
PT J
AU Cluver, ME
Jarrett, TH
Appleton, PN
Kraan-Korteweg, RC
Woudt, PA
Koribalski, BS
Donley, JL
Wakamatsu, K
Nagayama, T
AF Cluver, M. E.
Jarrett, T. H.
Appleton, P. N.
Kraan-Korteweg, R. C.
Woudt, P. A.
Koribalski, B. S.
Donley, J. L.
Wakamatsu, K.
Nagayama, T.
TI THE HIDDEN H I-MASSIVE LUMINOUS INFRARED GALAXY HIZOA J0836-43:
INSIDE-OUT GALAXY FORMATION
SO ASTROPHYSICAL JOURNAL LETTERS
LA English
DT Article
DE galaxies: individual (HIZOA J0836-43); galaxies: starburst; infrared:
galaxies
ID STAR-FORMING GALAXIES; POLYCYCLIC AROMATIC-HYDROCARBONS; SPECTRAL
ENERGY-DISTRIBUTIONS; SPITZER-SPACE-TELESCOPE; SURFACE BRIGHTNESS; DISK
GALAXIES; ULTRAVIOLET; EVOLUTION; EMISSION; UNIVERSE
AB HIZOA J0836-43 is an extreme gas-rich (M(H I) = 7.5 x 10(10) M(circle dot)) disk galaxy which lies hidden behind the strongly obscuring Vela region of the Milky Way. Utilizing observations from the Spitzer Space Telescope, we have found it to be a luminous infrared starburst galaxy with a star formation rate of similar to 21 M(circle dot) yr(-1), arising from exceptionally strong molecular PAH emission (L(7.7 mu m) = 1.50 x 10(9) L(circle dot)) and far-infrared emission from cold dust. The galaxy exhibits a weak mid-infrared continuum compared to other star-forming galaxies and U/LIRGs. This relative lack of emission from small grains suggests atypical interstellar medium conditions compared to other starbursts. We do not detect significant [Ne V] or [O IV], which implies an absent or very weak AGN. The galaxy possesses a prominent bulge of evolved stars and a stellar mass of 4.4(+/- 1.4) x 10(10) M(circle dot). With its plentiful gas supply and current star formation rate, a doubling of stellar mass would occur on a timescale of similar to 2 Gyr. Compared to local galaxies, HIZOA J0836-43 appears to be a "scaled up" spiral undergoing inside-out formation, possibly resembling stellar disk building processes at intermediate redshifts.
C1 [Cluver, M. E.; Kraan-Korteweg, R. C.; Woudt, P. A.] Univ Cape Town, Dept Astron, ZA-7700 Rondebosch, South Africa.
[Jarrett, T. H.] CALTECH, IPAC, Pasadena, CA 91125 USA.
[Appleton, P. N.] CALTECH, NASA, Herschel Sci Ctr, Pasadena, CA 91125 USA.
[Koribalski, B. S.] CISRO, Australia Telescope Natl Facil, Epping, NSW 1710, Australia.
[Donley, J. L.] Univ Arizona, Steward Observ, Tucson, AZ 85721 USA.
[Wakamatsu, K.] Gifu Univ, Fac Engn, Gifu 5011193, Japan.
[Nagayama, T.] Nagoya Univ, Dept Astrophys, Nagoya, Aichi 4648602, Japan.
RP Cluver, ME (reprint author), Univ Cape Town, Dept Astron, ZA-7700 Rondebosch, South Africa.
FU NRF; IPAC/Caltech; NASA
FX We thank D. Dale and SINGS, J. Howell and GOALS for data access. We are
grateful to S. Carey, G. Helou, S. Lord, J. Mazzarella, and B. Madore
for insightful discussions. Support for this work was provided by NASA
through an award issued by JPL/Caltech. M. C., R. K. K., and P. A. W.
thank the NRF for financial support. M. C. thanks IPAC/Caltech for
financial support through a Visiting Graduate Fellowship.
NR 34
TC 7
Z9 7
U1 0
U2 0
PU IOP PUBLISHING LTD
PI BRISTOL
PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND
SN 2041-8205
J9 ASTROPHYS J LETT
JI Astrophys. J. Lett.
PD OCT 10
PY 2008
VL 686
IS 1
BP L17
EP L20
DI 10.1086/592784
PG 4
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 398KO
UT WOS:000262731200005
ER
PT J
AU Georganopoulos, M
Sambruna, RM
Kazanas, D
Cillis, AN
Cheung, CC
Perlman, ES
Blundell, KM
Davis, DS
AF Georganopoulos, Markos
Sambruna, Rita M.
Kazanas, Demosthenes
Cillis, Analia N.
Cheung, Chi C.
Perlman, Eric S.
Blundell, Katherine M.
Davis, David S.
TI A NOVEL METHOD FOR MEASURING THE EXTRAGALACTIC BACKGROUND LIGHT: FERMI
APPLICATION TO THE LOBES OF FORNAX A
SO ASTROPHYSICAL JOURNAL LETTERS
LA English
DT Article
DE diffuse radiation; galaxies: active; quasars: general; radiation
mechanisms: nonthermal; X-rays: galaxies
ID COMPTON X-RAYS; GAMMA-RAYS; RADIO; GALAXIES; BLAZARS; SPECTRA;
RADIATION; PROBE
AB We describe a new method for measuring the extragalactic background light (EBL) through the detection of gamma-ray inverse Compton (IC) emission due to scattering of the EBL photons off relativistic electrons in the lobes of radio galaxies. Our method has no free physical parameters and is a powerful tool when the lobes are characterized by a high-energy sharp break or cutoff in their electron energy distribution (EED). We show that such a feature will produce a high-energy IC "imprint" of the EBL spectrum in which the radio lobes are embedded and show how this imprint can be used to derive the EBL. We apply our method to the bright nearby radio galaxy Fornax A, for which we demonstrate, using Wilkinson Microwave Anisotropy Probe (WMAP) and EGRET observations, that the EED of its lobes is characterized by a conveniently located cutoff, bringing the IC EBL emission into the Fermi Gamma-Ray Space Telescope energy range. We show that Fermi will set upper limits to the optical EBL and measure the more elusive infrared EBL.
C1 [Georganopoulos, Markos; Davis, David S.] Univ Maryland Baltimore Cty, Joint Ctr Astrophys, Dept Phys, Baltimore, MD 21228 USA.
[Georganopoulos, Markos; Sambruna, Rita M.; Kazanas, Demosthenes; Cillis, Analia N.; Cheung, Chi C.; Davis, David S.] NASA, Goddard Space Flight Ctr, Astrophys Sci Div, Greenbelt, MD 20771 USA.
[Perlman, Eric S.] Florida Inst Technol, Dept Phys & Space Sci, Melbourne, FL 32901 USA.
[Blundell, Katherine M.] Univ Oxford, Dept Phys, Oxford, England.
RP Georganopoulos, M (reprint author), Univ Maryland Baltimore Cty, Joint Ctr Astrophys, Dept Phys, Baltimore, MD 21228 USA.
NR 21
TC 22
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U1 0
U2 1
PU IOP PUBLISHING LTD
PI BRISTOL
PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND
J9 ASTROPHYS J LETT
JI Astrophys. J. Lett.
PD OCT 10
PY 2008
VL 686
IS 1
BP L5
EP L8
DI 10.1086/592833
PG 4
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 398KO
UT WOS:000262731200002
ER
PT J
AU Wiseman, SM
Arvidson, RE
Andrews-Hanna, JC
Clark, RN
Lanza, NL
Marais, DD
Marzo, GA
Morris, RV
Murchie, SL
Newsom, HE
Dobrea, EZN
Ollila, AM
Poulet, F
Roush, TL
Seelos, FP
Swayze, GA
AF Wiseman, Sandra M.
Arvidson, R. E.
Andrews-Hanna, J. C.
Clark, R. N.
Lanza, N. L.
Marais, D. Des
Marzo, G. A.
Morris, R. V.
Murchie, S. L.
Newsom, H. E.
Dobrea, E. Z. Noe
Ollila, A. M.
Poulet, F.
Roush, T. L.
Seelos, F. P.
Swayze, G. A.
TI Phyllosilicate and sulfate-hematite deposits within Miyamoto crater in
southern Sinus Meridiani, Mars
SO GEOPHYSICAL RESEARCH LETTERS
LA English
DT Article
ID TERRA-MERIDIANI; ARABIA TERRA; PLANUM; SPECTROSCOPY; SYSTEM
AB Orbital topographic, image, and spectral data show that sulfate- and hematite-bearing plains deposits similar to those explored by the MER rover Opportunity unconformably overlie the northeastern portion of the 160 km in diameter Miyamoto crater. Crater floor materials exhumed to the west of the contact exhibit CRISM and OMEGA NIR spectral signatures consistent with the presence of Fe/Mg-rich smectite phyllosilicates. Based on superposition relationships, the phyllosilicate-bearing deposits formed either in-situ or were deposited on the floor of Miyamoto crater prior to the formation of the sulfate-rich plains unit. These findings support the hypothesis that neutral pH aqueous conditions transitioned to a ground-water driven acid sulfate system in the Sinus Meridiani region. The presence of both phyllosilicate and sulfate- and hematite-bearing deposits within Miyamoto crater make it an attractive site for exploration by future rover missions.
C1 [Wiseman, Sandra M.; Arvidson, R. E.] Washington Univ, Dept Earth & Planetary Sci, St Louis, MO 63130 USA.
[Andrews-Hanna, J. C.] Colorado Sch Mines, Dept Geophys, Golden, CO 80401 USA.
[Clark, R. N.; Swayze, G. A.] US Geol Survey, Denver Fed Ctr, Denver, CO 80225 USA.
[Marais, D. Des; Marzo, G. A.; Roush, T. L.] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
[Lanza, N. L.] Univ New Mexico, Inst Meteorit, Albuquerque, NM 87131 USA.
[Morris, R. V.] NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA.
[Murchie, S. L.; Seelos, F. P.] Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA.
[Dobrea, E. Z. Noe] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[Poulet, F.] Univ Paris 11, Inst Astrophys Spatiale, F-91405 Orsay, France.
RP Wiseman, SM (reprint author), Washington Univ, Dept Earth & Planetary Sci, 1 Brookings Dr, St Louis, MO 63130 USA.
EM sandraw@levee.wustl.edu
RI Marzo, Giuseppe/A-9765-2015; Murchie, Scott/E-8030-2015; Seelos,
Frank/C-7875-2016
OI Murchie, Scott/0000-0002-1616-8751; Seelos, Frank/0000-0001-9721-941X
NR 39
TC 41
Z9 41
U1 1
U2 4
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0094-8276
EI 1944-8007
J9 GEOPHYS RES LETT
JI Geophys. Res. Lett.
PD OCT 10
PY 2008
VL 35
IS 19
AR L19204
DI 10.1029/2008GL035363
PG 5
WC Geosciences, Multidisciplinary
SC Geology
GA 359LG
UT WOS:000259987600005
ER
PT J
AU Chivian, D
Brodie, EL
Alm, EJ
Culley, DE
Dehal, PS
DeSantis, TZ
Gihring, TM
Lapidus, A
Lin, LH
Lowry, SR
Moser, DP
Richardson, PM
Southam, G
Wanger, G
Pratt, LM
Andersen, GL
Hazen, TC
Brockman, FJ
Arkin, AP
Onstott, TC
AF Chivian, Dylan
Brodie, Eoin L.
Alm, Eric J.
Culley, David E.
Dehal, Paramvir S.
DeSantis, Todd Z.
Gihring, Thomas M.
Lapidus, Alla
Lin, Li-Hung
Lowry, Stephen R.
Moser, Duane P.
Richardson, Paul M.
Southam, Gordon
Wanger, Greg
Pratt, Lisa M.
Andersen, Gary L.
Hazen, Terry C.
Brockman, Fred J.
Arkin, Adam P.
Onstott, Tullis C.
TI Environmental genomics reveals a single-species ecosystem deep within
earth
SO SCIENCE
LA English
DT Article
ID COMMUNITY STRUCTURE; SOUTH-AFRICA; SUBSURFACE; DIVERSITY; PROKARYOTES;
METABOLISM; BACTERIUM; WATER; SEA
AB DNA from low-biodiversity fracture water collected at 2.8-kilometer depth in a South African gold mine was sequenced and assembled into a single, complete genome. This bacterium, Candidatus Desulforudis audaxviator, composes > 99.9% of the microorganisms inhabiting the fluid phase of this particular fracture. Its genome indicates a motile, sporulating, sulfate-reducing, chemoautotrophic thermophile that can fix its own nitrogen and carbon by using machinery shared with archaea. Candidatus Desulforudis audaxviator is capable of an independent life-style well suited to long-term isolation from the photosphere deep within Earth's crust and offers an example of a natural ecosystem that appears to have its biological component entirely encoded within a single genome.
C1 [Chivian, Dylan; Dehal, Paramvir S.; Arkin, Adam P.] Univ Calif Berkeley, Lawrence Berkeley Lab, Phys Biosci Div, Berkeley, CA 94720 USA.
[Chivian, Dylan; Brodie, Eoin L.; Alm, Eric J.; Dehal, Paramvir S.; DeSantis, Todd Z.; Andersen, Gary L.; Hazen, Terry C.; Arkin, Adam P.] Virtual Inst Microbial Stress & Survival, Berkeley, CA 94720 USA.
[Brodie, Eoin L.; DeSantis, Todd Z.; Andersen, Gary L.; Hazen, Terry C.] Univ Calif Berkeley, Lawrence Berkeley Lab, Div Earth Sci, Berkeley, CA 94720 USA.
[Alm, Eric J.] MIT, Dept Biol Engn, Cambridge, MA 02139 USA.
[Alm, Eric J.] MIT, Dept Civil & Environm Engn, Cambridge, MA 02139 USA.
[Culley, David E.] Pacific NW Natl Lab, Energy & Efficiency Technol Div, Richland, WA 99352 USA.
[Gihring, Thomas M.] Florida State Univ, Dept Oceanog, Tallahassee, FL 32306 USA.
[Lapidus, Alla; Lowry, Stephen R.; Richardson, Paul M.] US DOE, Joint Genom Inst, Genom Technol Program, Berkeley, CA 94598 USA.
[Lin, Li-Hung] Natl Taiwan Univ, Dept Geosci, Taipei 106, Taiwan.
[Moser, Duane P.] Desert Res Inst, Div Earth & Ecosyst Sci, Las Vegas, NV 89119 USA.
[Southam, Gordon; Wanger, Greg] Univ Western Ontario, Dept Earth Sci, London, ON N6A 5B7, Canada.
[Pratt, Lisa M.] Indiana Univ, Dept Geol Sci, Bloomington, IN 47405 USA.
[Pratt, Lisa M.; Hazen, Terry C.; Onstott, Tullis C.] NASA Astrobiol Inst, IPTAI, Bloomington, IN 47405 USA.
[Brockman, Fred J.] Pacific NW Natl Lab, Div Biol Sci, Richland, WA 99352 USA.
[Arkin, Adam P.] Univ Calif Berkeley, Dept Bioengn, Berkeley, CA 94720 USA.
[Onstott, Tullis C.] Princeton Univ, Dept Geosci, Princeton, NJ 08544 USA.
RP Chivian, D (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Phys Biosci Div, Berkeley, CA 94720 USA.
EM DCChivian@lbl.gov
RI Lin, Li-Hung/K-8091-2012; Southam, Gordon/D-1983-2013; Brodie,
Eoin/A-7853-2008; Andersen, Gary/G-2792-2015; Arkin, Adam/A-6751-2008;
Hazen, Terry/C-1076-2012; Lapidus, Alla/I-4348-2013;
OI Southam, Gordon/0000-0002-8941-1249; Brodie, Eoin/0000-0002-8453-8435;
Andersen, Gary/0000-0002-1618-9827; Arkin, Adam/0000-0002-4999-2931;
Hazen, Terry/0000-0002-2536-9993; Lapidus, Alla/0000-0003-0427-8731;
Lin, Li-Hung/0000-0002-0985-1464
FU DOE, Office of Science, Office of Biological and Environmental Research,
Genomics Program: GTL [DE-AC02-05CH11231]; NASA Astrobiology Institute
[NNA01CC03A]; Howard Hughes Medical Institute
FX We thank J. Banfield and G. Tyson for helpful discussion; J. Bruckner
and B. Baker for assistance with microscopy; F. Warnecke for advice on
16S fluorescent in situ hybridization; T. Kieft, G. Zane, and the
MicrobesOnline team (M. Price, K. Keller, and K. Huang) for advice; and
D. Kershaw and colleagues at the Mponeng mine and AngloGold Ashanti
Limited, RSA. This work was part of the Virtual Institute for Microbial
Stress and Survival (http://vimss.lbl.gov), supported by DOE, Office of
Science, Office of Biological and Environmental Research, Genomics
Program: GTL through contract DE-AC02-05CH11231 between Lawrence
Berkeley National Laboratory and DOE. This work was also supported by
the NASA Astrobiology Institute through award NNA01CC03A to the IPTAI
Team co-directed by L.M.P. and T.C.O. A.P.A. received support from the
Howard Hughes Medical Institute. The genome sequence and 16S library
sequences reported in this study have been deposited in GenBank under
the accession numbers CP000860 and EU730965 to EU731008, respectively.
NR 26
TC 159
Z9 161
U1 26
U2 135
PU AMER ASSOC ADVANCEMENT SCIENCE
PI WASHINGTON
PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA
SN 0036-8075
J9 SCIENCE
JI Science
PD OCT 10
PY 2008
VL 322
IS 5899
BP 275
EP 278
DI 10.1126/science.1155495
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA 358FK
UT WOS:000259902300053
PM 18845759
ER
PT J
AU Datta-Barua, S
Mannucci, AJ
Walter, T
Enge, P
AF Datta-Barua, S.
Mannucci, A. J.
Walter, T.
Enge, P.
TI Altitudinal variation of midlatitude localized TEC enhancement from
ground- and space-based measurements
SO SPACE WEATHER-THE INTERNATIONAL JOURNAL OF RESEARCH AND APPLICATIONS
LA English
DT Article
AB We present terrestrial and space-based dual-frequency observations of a region of enhanced total electron content (TEC) over the southeastern United States at local nighttime during the geomagnetic storm of 29-31 October 2003. The apparently localized, large-amplitude, and nearly Earth-fixed midlatitude ionosphere disturbance contained about 10 m higher delay at Global Positioning System (GPS) L1 frequency than the nighttime background ionosphere TEC. Using the dual-frequency altimeter on board the Jason satellite, we show evidence that nearly all of the electron content was below its orbital altitude of 1300 km at 0000 local time on 31 October 2003. Dual frequency GPS measurements from the receiver on board the SAC-C satellite indicate that some portion of the electron content existed above the 700 km orbit altitude of SAC-C. We develop a horizontally piecewise constant regional model of the enhancement. We compare the model prediction of TEC with the SAC-C satellite GPS data to constrain the altitude of this enhanced TEC region. Our model indicates that the peak density of the anomalous region is at slightly higher altitude and greater in amplitude than that of the background. The TEC enhancement provides a concrete case study of an extreme scenario that both space-based and ground-based GPS augmentation systems must take into account in order to offer high-accuracy, high-integrity corrections to GPS for safety-of-life applications.
C1 [Datta-Barua, S.] Atmospher & Space Technol Res Associates, San Antonio, TX 78249 USA.
[Walter, T.; Enge, P.] Stanford Univ, Dept Aeronaut & Astronaut, Stanford, CA 94305 USA.
[Mannucci, A. J.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Datta-Barua, S (reprint author), Atmospher & Space Technol Res Associates, 12703 Spectrum Dr,Suite 101, San Antonio, TX 78249 USA.
EM seebany@astraspace.net
FU Federal Aviation Administration (FAA) Wide Area Augmentation System
(WAAS) program
FX This research was supported by the Federal Aviation Administration (FAA)
Wide Area Augmentation System (WAAS) program. Thanks to Glen Mattioli at
the University of Arkansas for providing data from the Caribbean North
American Plate Experiment (CANAPE). The authors thank Attila Komjathy at
Caltech/JPL for producing the CORS, IGS, and CANAPE networks' processed
data. The authors are grateful to Patricia Doherty and Susan Delay at
the Boston College Institute for Scientific Research for their help in
obtaining the Jason satellite data. Thanks to CONAE and NASA JPL for the
SAC-C GPS data. The CORS network data were made available by the
National Geodetic Survey. The International GNSS Service (IGS) is a
service of the International Association of Geodesy and of the
Federation of Astronomical and Geophysical Data Analysis Services. The
IRI model was made available by the Space Physics Data Facility at NASA.
NR 24
TC 4
Z9 4
U1 0
U2 3
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 1542-7390
J9 SPACE WEATHER
JI Space Weather
PD OCT 10
PY 2008
VL 6
IS 10
AR S10D06
DI 10.1029/2008SW000396
PG 15
WC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology &
Atmospheric Sciences
SC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology &
Atmospheric Sciences
GA 359MZ
UT WOS:000259992500001
ER
PT J
AU Englert, CR
Stevens, MH
Siskind, DE
Harlander, JM
Roesler, FL
Pickett, HM
von Savigny, C
Kochenash, AJ
AF Englert, Christoph R.
Stevens, Michael H.
Siskind, David E.
Harlander, John M.
Roesler, Fred L.
Pickett, Herbert M.
von Savigny, Christian
Kochenash, Andrew J.
TI First results from the Spatial Heterodyne Imager for Mesospheric
Radicals (SHIMMER): Diurnal variation of mesospheric hydroxyl
SO GEOPHYSICAL RESEARCH LETTERS
LA English
DT Article
ID SUMMER MESOSPHERE; MIDDLE ATMOSPHERE; OH; SPECTROSCOPY; OZONE; H2O
AB We present the first SHIMMER observations of the diurnal variation of mesospheric hydroxyl (OH). We compare our data with Aura Microwave Limb Sounder (MLS) observations at about 13h local time near 55 degrees N and find very good agreement. This validates the Spatial Heterodyne Spectroscopy technique for space-borne optical remote sensing applications. We extend our analysis to other local times, not observed by MLS, for latitudes near 55 degrees N in the summer of 2007. At 74 km, we find excellent agreement with a photochemical model, but above 76 km, significant model/data differences in the shape of the OH diurnal variation are observed.
C1 [Englert, Christoph R.; Stevens, Michael H.; Siskind, David E.] USN, Res Lab, Div Space Sci, Washington, DC 20375 USA.
[Harlander, John M.] St Cloud State Univ, Dept Phys Astron & Engn Sci, St Cloud, MN 56301 USA.
[Kochenash, Andrew J.] Computat Phys Inc, Springfield, VA 22151 USA.
[Pickett, Herbert M.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[Roesler, Fred L.] Univ Wisconsin, Dept Phys, Madison, WI 53706 USA.
[von Savigny, Christian] Univ Bremen, Inst Environm Phys & Remote Sensing, D-28359 Bremen, Germany.
RP Englert, CR (reprint author), USN, Res Lab, Div Space Sci, 4555 Overlook Ave SW,Code 7641, Washington, DC 20375 USA.
EM christoph.englert@nrl.navy.mil
RI von Savigny, Christian/B-3910-2014;
OI Stevens, Michael/0000-0003-1082-8955; Englert,
Christoph/0000-0002-2145-6168
FU Office of Naval Research; NASA
FX Funding for this research was provided by the Office of Naval Research.
SHIMMER is a joint program between the Naval Research Laboratory and the
DoD Space Test Program. The authors would like to thank Joel G. Cardon,
Ronen Feldman, John F. Moser, W. Layne Marlin, Charles M. Brown, Robert
R. Conway, Andrew N. Straatveit, Michael A. Carr, and Andrew W. Stephan
for their contributions to the SHIMMER project. Research at the Jet
Propulsion Laboratory, California Institute of Technology, was performed
under contract with NASA.
NR 24
TC 17
Z9 17
U1 3
U2 8
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0094-8276
J9 GEOPHYS RES LETT
JI Geophys. Res. Lett.
PD OCT 8
PY 2008
VL 35
IS 19
AR L19813
DI 10.1029/2008GL035420
PG 5
WC Geosciences, Multidisciplinary
SC Geology
GA 359LD
UT WOS:000259987300005
ER
PT J
AU Weitz, CM
Milliken, RE
Grant, JA
McEwen, AS
Williams, RME
Bishop, JL
AF Weitz, C. M.
Milliken, R. E.
Grant, J. A.
McEwen, A. S.
Williams, R. M. E.
Bishop, J. L.
TI Light-toned strata and inverted channels adjacent to Juventae and Ganges
chasmata, Mars
SO GEOPHYSICAL RESEARCH LETTERS
LA English
DT Article
ID MERIDIANI-PLANUM
AB Light-toned layered deposits on the plains adjacent to Juventae and Ganges Chasmata have been identified and analyzed with several instruments onboard the Mars Reconnaissance Orbiter, including HiRISE, CTX, and CRISM. Beds exhibit variations in brightness, color, polygonal fracturing, and erosional properties that are not seen in light-toned layered deposits within the chasmata. At both Juventae and Ganges, the light- toned layered deposits along the plains have associated features we interpret as fluvial, including sinuous ridges (inverted channels) that exhibit light-toned layering and an extensive valley system for the Ganges deposit. The strong correlation between the inverted channels and light-toned layered deposits suggests an association with fluvial-lacustrine processes, although pyroclastic and eolian activity may also be involved in their emplacement. The identification of potential fluviallacustrine layered deposits and associated valley networks suggests surface water flow in the Valles Marineris region that occurred for sustained periods during the Hesperian (3.7-3.0 Gyr).
C1 [Weitz, C. M.; Williams, R. M. E.] Planetary Sci Inst, Tucson, AZ 85719 USA.
[Bishop, J. L.] NASA ARC, SETI Inst, Mountain View, CA 94043 USA.
[Grant, J. A.] Smithsonian Inst, Natl Air & Space Museum, Washington, DC 20560 USA.
[Milliken, R. E.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[McEwen, A. S.] Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA.
RP Weitz, CM (reprint author), Planetary Sci Inst, 1700 E Ft Lowell, Tucson, AZ 85719 USA.
EM weitz@psi.edu
NR 16
TC 22
Z9 22
U1 0
U2 6
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0094-8276
EI 1944-8007
J9 GEOPHYS RES LETT
JI Geophys. Res. Lett.
PD OCT 8
PY 2008
VL 35
IS 19
AR L19202
DI 10.1029/2008GL035317
PG 5
WC Geosciences, Multidisciplinary
SC Geology
GA 359LD
UT WOS:000259987300004
ER
PT J
AU Leer, K
Bertelsen, P
Binau, CS
Olsen, LD
Drube, L
Falkenberg, TV
Haspang, MP
Madsen, MB
Olsen, M
Sykulska, H
Vijendran, S
Pike, WT
Staufer, U
Parrat, D
Lemmon, M
Hecht, MH
Mogensen, CT
Gross, MA
Goetz, W
Marshall, J
Britt, D
Smith, P
Shinohara, C
Woida, P
Woida, R
Tanner, R
Reynolds, R
Shaw, A
AF Leer, K.
Bertelsen, P.
Binau, C. S.
Olsen, L. Djernis
Drube, L.
Falkenberg, T. V.
Haspang, M. P.
Madsen, M. B.
Olsen, M.
Sykulska, H.
Vijendran, S.
Pike, W. T.
Staufer, U.
Parrat, D.
Lemmon, M.
Hecht, M. H.
Mogensen, C. T.
Gross, M. A.
Goetz, W.
Marshall, J.
Britt, D.
Smith, P.
Shinohara, C.
Woida, P.
Woida, R.
Tanner, R.
Reynolds, R.
Shaw, A.
TI Magnetic properties experiments and the Surface Stereo Imager
calibration target onboard the Mars Phoenix 2007 Lander: Design,
calibration, and science goals
SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS
LA English
DT Article
ID PATHFINDER; DEPOSITS; DUST; SPECTROMETER; MINERALOGY; ILMENITE; MISSION;
SOIL
AB The first NASA scout mission to Mars, Phoenix, launched 4 August will land in the northern part of Mars in the locality of 68 degrees N and 233 degrees E on 25 May 2008. Part of the science payload is the Magnetic Properties Experiments (MPE) that consists of two main experiments: the Improved Sweep Magnet Experiment (ISWEEP) and 10 sets of two Microscopy, Electrochemistry, and Conductivity Analyzer ( MECA) magnet substrates with embedded permanent magnets of different strength. The ISWEEP experiment is, as the name indicates, an improved version of the Sweep Magnet Experiments flown onboard the two Mars Exploration Rovers (MERs) Spirit and Opportunity. The sweep magnet is ring shaped and is designed to allow only nonmagnetic particles to enter a small circular area at the center of the surface of this structure. Results from this experiment have shown that on the MERs hardly any particles can be detected in the central area of this ring-shaped magnet. From this we have concluded that essentially all particles in the Martian atmosphere are magnetic in the sense that they are attracted to permanent magnets. In order to improve the sensitivity of the Sweep Magnet Experiment for detection of nonmagnetic or very weakly magnetic particles, the ISWEEP holds six ring-shaped magnets, somewhat larger than the sweep magnet of the MERs, and with six different background colors in the central area. The six different colors provide new possibilities for improved contrast between these background colors, i.e., any putative nonmagnetic particles should render these more easily detectable. The Surface Stereo Imager will also take advantage of the small clean areas in the ISWEEPs and use the presumably constant colors for radiometric calibration of images. The MECA magnets work as substrates in the MECA microscopy experiments; they are built to attract and hold magnetic particles from dust samples. The collected dust will then be examined by the optical microscope and the atomic force microscope in the MECA package.
C1 [Leer, K.; Bertelsen, P.; Binau, C. S.; Olsen, L. Djernis; Drube, L.; Falkenberg, T. V.; Haspang, M. P.; Madsen, M. B.; Olsen, M.] Univ Copenhagen, Niels Bohr Inst, DK-2100 Copenhagen, Denmark.
[Sykulska, H.; Vijendran, S.; Pike, W. T.] Univ London Imperial Coll Sci Technol & Med, Dept Elect & Elect Engn, London, England.
[Staufer, U.; Parrat, D.] Univ Neuchatel, Inst Microtechnol, CH-2000 Neuchatel, Switzerland.
[Lemmon, M.] Texas A&M Univ, Dept Atmospher Sci, College Stn, TX USA.
[Hecht, M. H.; Mogensen, C. T.; Gross, M. A.] CALTECH, Jet Prop Lab, Pasadena, CA USA.
[Goetz, W.] Max Planck Inst Sonnensyst Forsch, Lindau, Germany.
[Marshall, J.] SETI Inst, Mountain View, CA USA.
[Britt, D.] Univ Cent Florida, Dept Phys, Orlando, FL USA.
[Smith, P.; Shinohara, C.; Woida, P.; Woida, R.; Tanner, R.; Reynolds, R.; Shaw, A.] Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA.
RP Leer, K (reprint author), Univ Copenhagen, Niels Bohr Inst, Blegdamsvej 17, DK-2100 Copenhagen, Denmark.
RI Lemmon, Mark/E-9983-2010; Madsen, Morten/D-2082-2011; Staufer,
Urs/J-6866-2016
OI Lemmon, Mark/0000-0002-4504-5136; Madsen, Morten/0000-0001-8909-5111;
Staufer, Urs/0000-0002-3519-6467
FU Danish Research Agency; Lundbeck Foundation; Oticon
FX We would like to thank all those people who made this work possible,
including Michael Bernt, Morten L. Christensen, Jorgen Jorgensen, and
Per Thor Jonassen from the workshop at Niels Bohr Institute for
invaluable contributions to both design and manufacture of the Danish
equipment for Phoenix and the related tools and Tue Hassenkam,
Nano-Science Center, University of Copenhagen and Noemi Rozlosnik, The
Polymer Department, Risoe National Laboratory, DTU for help with AFM
simulation experiments. The results from this work have not been
evaluated here, but it turned out to be a very fruitful prestudy, which
was very valuable for this work. Also thanks go to Jaqueline Klovgaard
Jensen, Faculty of Life Sciences, University of Copenhagen; Mads Dam
Ellehoj, Ice and Climate and Earth and Planetary Physics, Niels Bohr
Institute, University of Copenhagen; and Michael Torben Hallundbaek and
N. Zahles Gymnasieskole, Copenhagen and Andreas Lemark, Ice and Climate,
Niels Bohr Institute, University of Copenhagen for all the work they put
into the calibration of the Phoenix radiometric calibration targets. And
finally thanks to the Danish Research Agency, the Lundbeck Foundation
and Oticon for financial support and B. Hapke and an anonymous reviewer
for their very constructive reviews that significantly improved this
paper.
NR 31
TC 10
Z9 10
U1 1
U2 5
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 2169-9097
EI 2169-9100
J9 J GEOPHYS RES-PLANET
JI J. Geophys. Res.-Planets
PD OCT 7
PY 2008
VL 113
AR E00A16
DI 10.1029/2007JE003014
PG 15
WC Geochemistry & Geophysics
SC Geochemistry & Geophysics
GA 359ML
UT WOS:000259991000001
ER
PT J
AU Fairfield, DH
Wing, S
Newell, PT
Ruohoniemi, JM
Gosling, JT
Skoug, RM
AF Fairfield, D. H.
Wing, S.
Newell, P. T.
Ruohoniemi, J. M.
Gosling, J. T.
Skoug, R. M.
TI Polar rain gradients and field-aligned polar cap potentials
SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
LA English
DT Article
ID LOW-ENERGY ELECTRONS; DENSITY SOLAR-WIND; LOW-ALTITUDE; PLASMA;
MAGNETOSPHERE; CUSP; PRECIPITATION; CONVECTION; ENTRY; IONOSPHERE
AB ACE SWEPAM measurements of solar wind field-aligned electrons have been compared with simultaneous measurements of polar rain electrons precipitating over the polar cap and detected by DMSP spacecraft. Such comparisons allow investigation of cross-polar-cap gradients in the intensity of otherwise-steady polar rain. The generally good agreement of the distribution functions, f, from the two data sources confirms that direct entry of solar electrons along open field lines is indeed the cause of polar rain. The agreement between the data sets is typically best on the side of the polar cap with most intense polar rain but the DMSP f's in less intense regions can be brought into agreement with ACE measurements by shifting all energies by a fixed amounts that range from tens to several hundred eV. In most cases these shifts are positive which implies that field-aligned potentials of these amounts exist on polar cap field lines which tend to retard the entry of electrons and produce the observed gradients. These retarding potentials undoubtedly appear in order to prevent the entry of low-energy electrons and maintain charge quasi-neutrality that would otherwise be violated since most tailward flowing magnetosheath ions are unable to follow polar rain electrons down to the polar cap. In more limited regions near the boundary of the polar cap there is sometimes evidence for field-aligned potentials of the opposite sign that accelerate polar rain electrons. A solar electron burst is also studied and it is concluded that electrons from such bursts can enter the magnetotail and precipitate in the same manner as polar rain.
C1 [Fairfield, D. H.] NASA, Goddard Space Flight Ctr, Space Weather Lab, Greenbelt, MD 20771 USA.
[Wing, S.; Newell, P. T.; Ruohoniemi, J. M.] Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA.
[Gosling, J. T.] Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80303 USA.
[Skoug, R. M.] Los Alamos Natl Lab, Los Alamos, NM 87545 USA.
RP Fairfield, DH (reprint author), NASA, Goddard Space Flight Ctr, Space Weather Lab, Greenbelt, MD 20771 USA.
EM mikeruo@vt.edu
FU NASA [NNG05GJ55G, NNX06AB87G]; NASA ACE program; U.S., Canada, UK,
France, Japan, South Africa, Italy, and Australia; NSF [ATM-0418101,
ATM-0703445, ATM-0538513]
FX Work at LASP has been supported by NASA grant NNG05GJ55G. Work at Los
Alamos was performed under the auspices of the U.S. Department of
Energy, with financial support from the NASA ACE program. Operation of
the SuperDARN radars is supported by the national funding agencies of
the U.S., Canada, UK, France, Japan, South Africa, Italy, and Australia.
J.M.R. acknowledges the support of NSF grant ATM-0418101 and S.W.
acknowledges the support of NASA grant NNX06AB87G and NSF grants
ATM-0703445 and ATM-0538513. We gratefully acknowledge the Center for
Space Sciences at the University of Texas at Dallas and the U.S. Air
Force for providing the DMSP thermal plasma data. M.L. Kaiser is thanked
for useful discussions and for the preparation of the Wind Waves data.
N. Gopalswamy helped in the interpretation of solar data.
NR 36
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U1 0
U2 1
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0148-0227
J9 J GEOPHYS RES-SPACE
JI J. Geophys. Res-Space Phys.
PD OCT 7
PY 2008
VL 113
IS A10
AR A10203
DI 10.1029/2008JA013437
PG 15
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 359MS
UT WOS:000259991700003
ER
PT J
AU Jiang, H
Brown, DP
Nikolaev, P
Nasibulin, AG
Kauppinen, EI
AF Jiang, H.
Brown, D. P.
Nikolaev, P.
Nasibulin, A. G.
Kauppinen, E. I.
TI Determination of helicities in unidirectional assemblies of graphitic or
graphiticlike tubular structures
SO APPLIED PHYSICS LETTERS
LA English
DT Article
ID WALLED CARBON NANOTUBES; BORON-NITRIDE NANOTUBES; ELECTRON-DIFFRACTION;
BUNDLES
AB Here we propose a universal method for the determination of all helicities present in unidirectional assemblies of hexagon-based graphitic or graphiticlike tubular structures, e.g., multiwalled or bundled carbon nanotubes (CNTs) or boron-nitride nanotubes and their structural analogs. A critical dimension characteristic of a fundamental structural property, i.e., the atomic bond length, is discerned from electron diffraction patterns by which all helicities present in the assemblies are identified. Using this method, we determine the helicity population in a single-walled CNT sample produced by laser ablation technique. (C) 2008 American Institute of Physics.
C1 [Jiang, H.; Nasibulin, A. G.; Kauppinen, E. I.] Helsinki Univ Technol, Dept Appl Phys, FIN-02150 Espoo, Finland.
[Jiang, H.; Nasibulin, A. G.; Kauppinen, E. I.] Helsinki Univ Technol, Ctr New Mat, FIN-02150 Espoo, Finland.
[Brown, D. P.] Canatu Ltd, Espoo 02150, Finland.
[Nikolaev, P.] NASA, JSC, ERC, Houston, TX 77258 USA.
[Kauppinen, E. I.] Tech Res Ctr Finland, Espoo 02044, Finland.
RP Jiang, H (reprint author), Helsinki Univ Technol, Dept Appl Phys, POB 5100, FIN-02150 Espoo, Finland.
EM hua.jiang@tkk.fi; esko.kauppinen@tkk.fi
RI Nikolaev, Pavel/B-9960-2009; Nasibulin, Albert/N-7232-2013;
OI Nasibulin, Albert/0000-0001-8308-3662; Jiang,
Hongxing/0000-0001-9892-4292
FU European Commission [NMp4-CT-2006-033350]
FX H. J. is grateful to Professor Ph. Lambin for providing the FORTRAN code
of their DIFFRACT simulation program. This work has been supported in
part by the European Commission under the 6 Framework Programme (STREP
Project BNC Tubes) (Contract No. NMp4-CT-2006-033350)
NR 22
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PU AMER INST PHYSICS
PI MELVILLE
PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1,
MELVILLE, NY 11747-4501 USA
SN 0003-6951
J9 APPL PHYS LETT
JI Appl. Phys. Lett.
PD OCT 6
PY 2008
VL 93
IS 14
AR 141903
DI 10.1063/1.2993217
PG 3
WC Physics, Applied
SC Physics
GA 359DC
UT WOS:000259965400013
ER
PT J
AU Farrell, WM
Stubbs, TJ
Delory, GT
Vondrak, RR
Collier, MR
Halekas, JS
Lin, RP
AF Farrell, W. M.
Stubbs, T. J.
Delory, G. T.
Vondrak, R. R.
Collier, M. R.
Halekas, J. S.
Lin, R. P.
TI Concerning the dissipation of electrically charged objects in the
shadowed lunar polar regions
SO GEOPHYSICAL RESEARCH LETTERS
LA English
DT Article
ID IN-CELL SIMULATIONS; PLASMA; WAKE
AB NASA recently suggested the construction of a lunar outpost at the south pole near the rim of Shackleton crater. While there are a number of advantages to such a base, the region will have periods of time when there is limited or no solar illumination - thereby reducing photoelectric and solar wind plasma currents compared to most of the lunar dayside. As a consequence of this reduction in environmental currents, we find that human systems charged by contact electrification with the regolith (e.g., roving, excavation) will have increased difficulty in removing accumulated electric charge. This situation is especially true within the cold, shadowed regions adjacent to the terminator (such as within Shackleton crater itself) where there are essentially no photoelectric currents, vastly reduced plasma currents (due to the local wake) and a highly-reduced regolith conductivity. In essence, there is no pathway for accumulated charge to "leak away'' or dissipate, thereby creating an electrostatic hazard. Calculated dissipation timescales are found to be similar to 1 millisecond in the weakly sunlit terminator region and dayside but could approach 100's of seconds in the "current-starved'' shadowed regions.
C1 [Farrell, W. M.; Vondrak, R. R.; Collier, M. R.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
[Delory, G. T.; Halekas, J. S.; Lin, R. P.] Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA.
[Stubbs, T. J.] Univ Maryland, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21201 USA.
RP Farrell, WM (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
EM william.farrell@gsfc.nasa.gov
RI Collier, Michael/I-4864-2013; Stubbs, Timothy/I-5139-2013; Farrell,
William/I-4865-2013;
OI Collier, Michael/0000-0001-9658-6605; Stubbs,
Timothy/0000-0002-5524-645X; Halekas, Jasper/0000-0001-5258-6128
FU GSFC IRAD; NASA/ETDP
FX We are grateful for a GSFC IRAD award and NASA/ETDP funding that
supported this effort.
NR 15
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PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0094-8276
J9 GEOPHYS RES LETT
JI Geophys. Res. Lett.
PD OCT 4
PY 2008
VL 35
IS 19
AR L19104
DI 10.1029/2008GL034785
PG 5
WC Geosciences, Multidisciplinary
SC Geology
GA 356UO
UT WOS:000259803300003
ER
PT J
AU Satheesh, SK
Moorthy, KK
Babu, SS
Vinoj, V
Dutt, CBS
AF Satheesh, S. K.
Moorthy, K. Krishna
Babu, S. Suresh
Vinoj, V.
Dutt, C. B. S.
TI Climate implications of large warming by elevated aerosol over India
SO GEOPHYSICAL RESEARCH LETTERS
LA English
DT Article
ID BROWN CLOUDS; BLACK CARBON; RADIATION
AB Wide-ranging multi-platform data from a major field campaign conducted over Indian region was used to estimate the energy absorbed in ten layers of the atmosphere. We found that during pre-monsoon season, most of Indian region is characterized by elevated aerosol layers. Three-fold increase in aerosol extinction coefficient was observed at higher atmospheric layers (>2 km) compared to that near the surface and a substantial fraction (as much as 50 to 70%) of aerosol optical depth was found contributed by aerosols above (reflecting) clouds. Consequent absorption and hence strong warming above clouds was found larger by several degrees (K) compared to that near the surface. The aerosol-induced elevated warming was mostly confined below 2 km over northern Indian Ocean while found up to 4 km over central India, thus exhibiting strong meridional gradients (similar to 4 K) at atmospheric levels above 2 km. Climate implications of the large elevated warming are discussed.
C1 [Satheesh, S. K.; Vinoj, V.] Indian Inst Sci, Ctr Atmospher & Ocean Sci, Bangalore 560012, Karnataka, India.
[Dutt, C. B. S.] Indian Space Res Org, Bangalore 560094, Karnataka, India.
[Moorthy, K. Krishna; Babu, S. Suresh] Vikram Sarabhai Space Ctr, Space Phys Lab, Trivandrum 695022, Kerala, India.
[Satheesh, S. K.] NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA.
RP Satheesh, SK (reprint author), Indian Inst Sci, Ctr Atmospher & Ocean Sci, Bangalore 560012, Karnataka, India.
EM satheesh@caos.iisc.ernet.in
RI Vinoj, V./C-3241-2008;
OI Vinoj, V./0000-0001-8573-6073; Moorthy, K. Krishna/0000-0002-7234-3868
FU Integrated Campaign; Radiation Budget (ICARB); Department of Science and
Technology, New Delhi; NASA Postdoctoral Program; Oak Ridge Associated
Universities
FX This research work was carried out under Integrated Campaign for
Aerosols, gases, and Radiation Budget (ICARB) field campaign of
ISRO-GBP, and the authors thank V. Jayaraman and R. Sridharan for their
support. The authors thank Department of Science and Technology, New
Delhi, for supporting Micro Pulse Lidar (MPL) used in this work. Authors
are grateful to K. Radhakrishnan, aircraft team (headed by K.
Kalyanaraman and V. Raghu Venkataraman), Rasik Ravindra, and M. Sudhakar
for their excellent cooperation and support through out the campaign.
Part of this research was carried out when one of the authors (SKS) was
supported by an appointment to the NASA Postdoctoral Program at the NASA
Goddard Space Flight Center, administered by Oak Ridge Associated
Universities through a contract with NASA.
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PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0094-8276
J9 GEOPHYS RES LETT
JI Geophys. Res. Lett.
PD OCT 4
PY 2008
VL 35
IS 19
AR L19809
DI 10.1029/2008GL034944
PG 6
WC Geosciences, Multidisciplinary
SC Geology
GA 356UO
UT WOS:000259803300006
ER
PT J
AU Aumann, HH
Ruzmaikin, A
Teixeira, J
AF Aumann, Hartmut H.
Ruzmaikin, Alexander
Teixeira, Joao
TI Frequency of severe storms and global warming
SO GEOPHYSICAL RESEARCH LETTERS
LA English
DT Article
ID HURRICANE INTENSITY; CLIMATE; TRENDS
AB We use five years of data from the Atmospheric Infrared Sounder (AIRS) to develop a correlation between the frequency of Deep Convective Clouds (DCC) and the zonal mean tropical surface temperature. AIRS data show that the frequency of DCC in the tropical oceans is very temperature sensitive, increasing 45% per 1 K increase of the zonal mean surface temperature. The combination of the sensitivity of the DCC frequency to temperature indicates that the frequency of DCC, and as a consequence the frequency of severe storms, increases at the rate of 6%/decade with the current +0.13 K/decade rate of global warming. This result is only qualitatively consistent with state-of-the-art climate models, where the frequency of the most intense rain events increases with global warming.
C1 [Aumann, Hartmut H.; Ruzmaikin, Alexander; Teixeira, Joao] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Aumann, HH (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM aumann@jpl.nasa.gov
FU Caltech's Jet Propulsion Laboratory; NASA
FX We acknowledge helpful discussions with Y. Yung, Brian Kahn and W. G.
Read and critical reading by Steve Broberg. Sergio DeSouza-Machado
(UMBC) generated the DCC model spectra for the evaluation of tropopause
penetration. This work was carried out at Caltech's Jet Propulsion
Laboratory under contract with NASA.
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PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0094-8276
EI 1944-8007
J9 GEOPHYS RES LETT
JI Geophys. Res. Lett.
PD OCT 3
PY 2008
VL 35
IS 19
AR L19805
DI 10.1029/2008GL034562
PG 4
WC Geosciences, Multidisciplinary
SC Geology
GA 356UN
UT WOS:000259803200001
ER
PT J
AU Hakkinen, S
Proshutinsky, A
Ashik, I
AF Hakkinen, Sirpa
Proshutinsky, Andrey
Ashik, Igor
TI Sea ice drift in the Arctic since the 1950s
SO GEOPHYSICAL RESEARCH LETTERS
LA English
DT Article
ID COLD HALOCLINE LAYER; CYCLONE ACTIVITY; OCEAN; VARIABILITY; TRENDS
AB Sea ice drift data (from Russian North Pole stations, various ice camps, and the International Arctic Buoy Program) and surface wind stress data from the NCAR/NCEP Reanalysis are analyzed to determine their long-term trends and causality. The study finds that both parameters (ice drift and wind stress) show gradual acceleration over last 50 years. Significant positive trends are present in both winter and summer data. The major cause of observed positive trends is increasing Arctic storm activity over the Transpolar Drift Stream caused by a shift of storm tracks toward higher latitudes. It is speculated, with some observational evidence, that the increased stirring of the ocean by winds could hasten the transition of the Arctic toward a weakly stratified ocean with a potential for deep convection and a new sink for atmospheric CO2.
C1 [Hakkinen, Sirpa] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
[Ashik, Igor] Arctic & Antarctic Res Inst, St Petersburg 199397, Russia.
[Proshutinsky, Andrey] Woods Hole Oceanog Inst, Woods Hole, MA 02543 USA.
RP Hakkinen, S (reprint author), NASA, Goddard Space Flight Ctr, Code 614-2, Greenbelt, MD 20771 USA.
EM sirpa.hakkinen@nasa.gov
RI Hakkinen, Sirpa/E-1461-2012
FU NASA Headquarters; NSF; IARC
FX We are grateful for funding from the NASA Headquarters, NSF and IARC.
Comments from two anonymous reviewers were very helpful in improving the
manuscript. We thank Denise Worthen for help with graphics and Vicky
Cullen for technical editing.
NR 20
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U2 13
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0094-8276
EI 1944-8007
J9 GEOPHYS RES LETT
JI Geophys. Res. Lett.
PD OCT 3
PY 2008
VL 35
IS 19
AR L19704
DI 10.1029/2008GL034791
PG 5
WC Geosciences, Multidisciplinary
SC Geology
GA 356UN
UT WOS:000259803200002
ER
PT J
AU Chan, KL
Mayr, HG
AF Chan, K. L.
Mayr, H. G.
TI A shallow convective model for Jupiter's alternating wind bands
SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS
LA English
DT Article
ID TURBULENT COMPRESSIBLE CONVECTION; ZONAL WINDS; THERMAL-CONVECTION; DEEP
ATMOSPHERE; PLANETS; DRIVEN; FLOW; SATURN
AB The dynamics of a thin atmospheric layer (1 - 340 bar) below the cloud tops of Jupiter is simulated with a three-dimensional, nonlinear transformed spectral model. The gas is compressible and stratified. Commensurate with the observed emitted radiation from Jupiter's atmosphere, the transport of the planet's internal energy in the lower region is taken to be convective, but solar heating is not accounted for. In qualitative agreement with observations, the model produces alternating wind bands and a dominant prograde equatorial jet. The zonal wind speed at the equator is within a factor of 2 of the observed values.
C1 [Chan, K. L.] Hong Kong Univ Sci & Technol, Dept Math, Hong Kong, Hong Kong, Peoples R China.
[Mayr, H. G.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
RP Chan, KL (reprint author), Hong Kong Univ Sci & Technol, Dept Math, ClearWater Bay, Hong Kong, Hong Kong, Peoples R China.
EM maklchan@ust.hk
OI Chan, Kwing/0000-0002-6428-1812
FU Hong Kong Research Grants Council
FX K.L.C. thanks the Hong Kong Research Grants Council for support. The
manuscript has been much improved by the reviewers' insightful comments.
NR 26
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U2 2
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0148-0227
J9 J GEOPHYS RES-PLANET
JI J. Geophys. Res.-Planets
PD OCT 3
PY 2008
VL 113
IS E10
AR E10002
DI 10.1029/2008JE003124
PG 7
WC Geochemistry & Geophysics
SC Geochemistry & Geophysics
GA 356VD
UT WOS:000259804800001
ER
PT J
AU Chronis, TG
Goodman, SJ
Cecil, D
Buechler, D
Robertson, FJ
Pittman, J
Blakeslee, RJ
AF Chronis, T. G.
Goodman, S. J.
Cecil, D.
Buechler, D.
Robertson, F. J.
Pittman, J.
Blakeslee, R. J.
TI Global lightning activity from the ENSO perspective
SO GEOPHYSICAL RESEARCH LETTERS
LA English
DT Article
ID NINO SOUTHERN-OSCILLATION; 1997-98 EL-NINO; OPTICAL TRANSIENT DETECTOR;
EQUATORIAL PACIFIC; PRECIPITATION; VARIABILITY; SATELLITE; EVOLUTION;
RAINFALL; EVENT
AB The recently reprocessed (1998-2006) OTD/LIS space-based lightning database is used to investigate the global lightning climatology in response to the ENSO cycle. Temporal correlation maps depicting lightning anomalies-NINO3.4 identify areas that generally follow patterns similar to the widely documented ENSO-related precipitation anomalies. However, areas having statistically significant lightning anomaly-NINO3.4 correlations accompanied by non-significant precipitation anomaly-NINO3.4 correlations are found over the mid-latitudes in both hemispheres. Analysis shows that these areas are related to upper level circulation anomalies (enhanced wind shear) induced by the corresponding ENSO phase. A special case is observed over the western Maritime continent where typical drought conditions during the warm ENSO phase are related to enhanced lightning activity. Further attention is given toward identifying areas over which consistent thunderstorm activity is observed during the two major warm and cold ENSO phases of the past decade. Their spatial distribution shows strong regional preference and in general agrees with the already established ENSO-related precipitation regimes.
C1 [Chronis, T. G.] Hellen Ctr Marine Res, Anavissos 19013, Greece.
[Buechler, D.; Robertson, F. J.; Pittman, J.; Blakeslee, R. J.] NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35805 USA.
[Cecil, D.] Univ Alabama, Natl Space Sci & Technol Ctr, Huntsville, AL 35805 USA.
[Goodman, S. J.] NOAA, Natl Environm Satellite Data & Informat Syst, Camp Springs, MD 20746 USA.
RP Chronis, TG (reprint author), Hellen Ctr Marine Res, POB 712, Anavissos 19013, Greece.
EM themis@hcmr.gr; steve.goodman@noaa.gov; cecild@uah.edu;
dennis.buechler@msfc.nasa.gov; pete.robertson@nasa.gov;
jasna.pittman@nasa.gov; rich.blakeslee@nasa.gov
FU GOES-R Program Office
FX The TRMM scientific team provided the OTD/LIS dataset. This can be
downloaded at http://thunder.nsstc.nasa.gov/data/. We thank the NASA
Post Doctoral Program and Ramesh Kakar of NASA Headquarters for their
support of this research. The first author also acknowledges the
contribution of the Oak Ridge Associated Universities. Finally we thank
the GOES-R Program Office for the funding it provided in support of GLM
risk reduction science. The views, opinions, and findings contained
herein are those of the authors and should not be construed as an
official NASA, NOAA, or U. S. Government position, policy, or decision.
NR 24
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U2 8
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0094-8276
J9 GEOPHYS RES LETT
JI Geophys. Res. Lett.
PD OCT 2
PY 2008
VL 35
IS 19
AR L19804
DI 10.1029/2008GL034321
PG 5
WC Geosciences, Multidisciplinary
SC Geology
GA 356UM
UT WOS:000259803100001
ER
PT J
AU Hansen, JC
Friedl, RR
Sander, SP
AF Hansen, Jaron C.
Friedl, Randall R.
Sander, Stanley P.
TI Kinetics of the OH+ClOOCl and OH+Cl(2)O reactions: Experiment and theory
SO JOURNAL OF PHYSICAL CHEMISTRY A
LA English
DT Article
ID RATE CONSTANTS; CHLORINE PEROXIDE; CLO; RADICALS; SPECTRUM; OH;
DECOMPOSITION; PRODUCT; CL2O; NO
AB The rate coefficients for the reactions OH + ClOOCl -> HOCl + ClOO (eq 5) and OH + Cl(2)O -> HOCl + ClO (eq 6) were measured using a fast flow reactor coupled with molecular beam quadrupole mass spectrometry. OH was detected using resonance fluorescence at 309 nm. The measured Arrhenius expressions for these reactions are k(5) = (6.0 +/- 3.5) x 10(-13) exp((670 +/- 230)/T) cm(3) molecule(-1) s(-1) and k(6) = (5.1 +/- 1.5) x 10(-12) exp((100 +/- 92)/T) cm(3) molecule(-1) s(-1), respectively, where the uncertainties are reported at the 2 sigma level. Investigation of the OH + ClOOCl potential energy surface using high level ab initio calculations indicates that the reaction occurs via a chlorine abstraction from ClOOCl by the OH radical. The lowest energy pathway is calculated to proceed through a weak ClOOCl-OH prereactive complex that is bound by 2.6 kcal mol(-1) and leads to ClOO and HOCl products. The transition state to product formation is calculated to be 0.59 kcal mol(-1) above the reactant energy level. Inclusion of the OH + ClOOCl rate data into an atmospheric model indicates that this reaction contributes more than 15% to ClOOCl loss during twilight conditions in the Arctic stratosphere. Reducing the rate of ClOOCl photolysis, as indicated by a recent re-examination of the ClOOCl UV absorption spectrum, increases the contribution of the OH + ClOOCl reaction to polar stratospheric loss of ClOOCl.
C1 [Hansen, Jaron C.; Friedl, Randall R.; Sander, Stanley P.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Hansen, JC (reprint author), Brigham Young Univ, Dept Chem & Biochem, Provo, UT 84602 USA.
EM jhansen@chem.byu.edu
FU Jet Propulsion Laboratory; California Institute of Technology; National
Aeronautics and Space Administration; NASA Upper Atmosphere Research and
Tropospheric Chemistry Programs
FX Acknowledgment. The authors gratefully acknowledge the technical
assistance of Dave Natzic, and valuable discussions with Trevor Ingham
and Kyle Bayes, and the modeling work of Ross Salawitch. We thank Kyle
Bayes for his critical reading of the manuscript. The research described
in this paper was carried out at the Jet Propulsion Laboratory,
California Institute of Technology, under contract to the National
Aeronautics and Space Administration. This work was supported by the
NASA Upper Atmosphere Research and Tropospheric Chemistry Programs.
NR 22
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U1 2
U2 4
PU AMER CHEMICAL SOC
PI WASHINGTON
PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA
SN 1089-5639
J9 J PHYS CHEM A
JI J. Phys. Chem. A
PD OCT 2
PY 2008
VL 112
IS 39
BP 9229
EP 9237
DI 10.1021/jp8007706
PG 9
WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical
SC Chemistry; Physics
GA 353FP
UT WOS:000259551800007
PM 18707064
ER
PT J
AU Yi, WH
Malkovskiy, A
Chu, QH
Sokolov, AP
Colon, ML
Meador, M
Pang, Y
AF Yi, Wenhui
Malkovskiy, Andrey
Chu, Qinghui
Sokolov, Alexei P.
Colon, Marisabel Lebron
Meador, Michael
Pang, Yi
TI Wrapping of single-walled carbon nanotubes by a pi-conjugated polymer:
The role of polymer conformation-controlled size selectivity
SO JOURNAL OF PHYSICAL CHEMISTRY B
LA English
DT Article
ID KATAURA PLOT; DISPERSION; SEPARATION; FUNCTIONALIZATION; SPECTROSCOPY;
TRANSISTORS; COMPOSITES
AB Wrapping of a single-walled carbon nanotube (SWNT) was examined by using a poly[(m-phenylenevinylene)-alt-(p-phenylenevinylene)] (PmPV) derivative. The polymer's intrinsic ability in forming a helical conformation was found to play an essential role in the separation of nanotubes. Among about 15 tubes present in the pure SWNT (HiPcoTM) sample, the polymer was found to selectively pick up the tubes (11,6), (11,7) and (12,6), which correspond to tube diameters of 1.19, 1.25 and 1.24 nm, respectively. The SWNTs of smaller diameters were held loosely by the PmPV, and were gradually dropped out under centrifugation. The suspension solution prepared from the SWNT and PmPV was not permanently stable, with precipitation occurring after a few weeks. Irradiation in the UV-vis region exhibited a catalytic effect to shorten the precipitation time to hours. Those tubes, which were held loosely by PmPV, were quickly separated from the suspension during the irradiation process.
C1 [Yi, Wenhui; Chu, Qinghui; Pang, Yi] Univ Akron, Dept Chem, Akron, OH 44325 USA.
[Malkovskiy, Andrey; Sokolov, Alexei P.] Univ Akron, Dept Polymer Sci, Akron, OH 44325 USA.
[Colon, Marisabel Lebron; Meador, Michael] NASA, Glenn Res Ctr, Struct & Mat Div, Cleveland, OH 44135 USA.
[Yi, Wenhui] Xi An Jiao Tong Univ, Sch Informat & Elect Engn, Dept Elect Sci & Technol, Xian 710049, Peoples R China.
RP Pang, Y (reprint author), Univ Akron, Dept Chem, Akron, OH 44325 USA.
FU University of Akron; NASA [C3-NN1044]; Cooperative Center in Polymer
Photonics
FX Y.P. is grateful for the financial supports from The University of Akron
and NASA (Grant C3-NN1044). A.P.S. acknowledges the financial support
from the Air Force through the Cooperative Center in Polymer Photonics.
NR 39
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PU AMER CHEMICAL SOC
PI WASHINGTON
PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA
SN 1520-6106
J9 J PHYS CHEM B
JI J. Phys. Chem. B
PD OCT 2
PY 2008
VL 112
IS 39
BP 12263
EP 12269
DI 10.1021/jp804083n
PG 7
WC Chemistry, Physical
SC Chemistry
GA 353FR
UT WOS:000259552000014
PM 18774842
ER
PT J
AU Summers, R
Coleman, T
Steven, P
Martin, D
AF Summers, Richard
Coleman, Thomas
Steven, Platts
Martin, David
TI Systems analysis of the mechanisms of cardiac diastolic function changes
after microgravity exposure
SO ACTA ASTRONAUTICA
LA English
DT Article
CT 16th IAA Humans in Space Symposium
CY MAY 20-24, 2007
CL Beijing, PEOPLES R CHINA
SP Int Acad Astronaut
DE diastolic functions; microgravity; Digital Astronaut
ID SPACEFLIGHT-INDUCED CHANGES; LEFT-VENTRICULAR MASS; WATER-CONTENT;
VOLUME; STIFFNESS; PRESSURE
AB Detailed information concerning cardiac function was collected by two-dimensional and M-mode echocardiography at 10 days before flight and 3 h after landing in astronauts returning from shuttle missions. A comparative analysis of this data suggests that cardiac diastolic function is reduced after microgravity exposure with little or no change in systolic function as measured by ejection fraction However. the mechanisms responsible for these adaptations have not been determined. In this study, an integrative computer model of human physiology that forms the framework for the Digital Astronaut Project (Guyton/Coleman/Summers Model) was used in a systems analysis of the echocardiographic data in the context of general cardiovascular physiologic functioning. The physiologic mechanisms involved in the observed changes were then determined by a dissection of model interrelationships. The systems analysis of possible physiologic mechanisms involved reveals that a loss of fluid from the myocardial interstitial space may lead to a stiffening of the myocardium and could potentially result ill some of the cardiac diastolic dysfunction seen postflight. The cardiovascular dynamics may be different during spaceflight. (C) 2008 Elsevier Ltd. All rights reserved.
C1 [Summers, Richard; Coleman, Thomas] Univ Mississippi, Med Ctr, Jackson, MS 39216 USA.
[Steven, Platts] NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA.
[Martin, David] Wyle Labs, Houston, TX USA.
RP Summers, R (reprint author), Univ Mississippi, Med Ctr, Jackson, MS 39216 USA.
EM rsummers@pol.net
NR 19
TC 3
Z9 4
U1 2
U2 3
PU PERGAMON-ELSEVIER SCIENCE LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
SN 0094-5765
J9 ACTA ASTRONAUT
JI Acta Astronaut.
PD OCT-NOV
PY 2008
VL 63
IS 7-10
BP 722
EP 726
DI 10.1016/j.actaastro.2008.02.010
PG 5
WC Engineering, Aerospace
SC Engineering
GA 351FE
UT WOS:000259409100005
ER
PT J
AU Scheuring, R
Conkin, J
Jones, JA
Gernhardt, ML
AF Scheuring, Richard
Conkin, Johnny
Jones, Jeffrey A.
Gernhardt, Michael L.
TI Risk assessment of physiological effects of atmospheric composition and
pressure in Constellation vehicles
SO ACTA ASTRONAUTICA
LA English
DT Article
CT 16th IAA Humans in Space Symposium
CY MAY 20-24, 2007
CL Beijing, PEOPLES R CHINA
SP Int Acad Astronaut
DE Acute Mountain Sickness; hypoxia; blood viscosity; spacecraft
atmospheres; oxygen
ID ACUTE MOUNTAIN-SICKNESS; HEAD-DOWN TILT; ACUTE ALTITUDE EXPOSURE;
SIMULATED ALTITUDE; BED REST; NORMOBARIC HYPOXIA; OXYGEN-SATURATION;
HYPOBARIC HYPOXIA; FLUID BALANCE; RESPONSES
AB Introduction: To limit the risk of fire and reduce denitrogenation time to prevent decompression sickness to support frequent extravehicular activities on the Moon, a hypobaric (P(B) = 414 mmHg) and mildly hypoxic (ppO(2) = 132 mmHg, 32% O(2)-68% N(2)) living environment is considered for the Crew Exploration Vehicle (CEV) and Lunar Surface Access Module (LSAM). With acute change in ppO(2) from 145-178 mmHg at standard vehicular operating pressure to less than 125 mmHg at desired lunar surface vehicular operating pressures, there is the possibility that some crewmembers may develop symptoms of Acute Mountain Sickness (AMS). The signs and symptoms of AMS (headache plus nausea, dizziness, fatigue, or sleeplessness) could impact crew health and performance on lunar surface missions.
Methods: We performed a literature review on the topic of the physiological effects of reduced ppO(2) and absolute pressure. The results of nine studies were evaluated.
Results: There is evidence for an absolute pressure effect per se on AMS, so the higher the altitude for a given hypoxic alveolar oxygen (O(2)) partial pressure (P(A)O(2)), the greater the AMS response is. Between 7% and 25% of adults may experience mild AMS near 2000 m altitude following a rapid ascent from sea level while breathing air (6500 ft, acute P(A)O(2) = 75 mmHg). The operational experience with the Shuttle staged denitrogenation protocol at 528 mmHg (3048 m) while breathing 26.5% O(2) (acute P(A)O(2) = 85 mmHg) in astronauts adapting to microgravity suggests a similar likely experience in the proposed CEV environment.
Conclusions: We believe the risk of mild AMS is greater given a P(A)O(2) of 77 mmHg at 4876 m altitude while breathing 32% O(2) than at 1828 in altitude while breathing 21% O(2). Only susceptible astronauts would develop mild and transient AM S with prolonged exposure to 414 mmHg (4876 m) while breathing 32% O(2) (acute P(A)O(2) = 77 mmHg). So the following may be employed for operational risk reduction: (1) develop procedures to increase PB as needed in the CEV, and use a gradual or staged reduction in cabin pressure during lunar outbound; (2) train crews for symptoms of hypoxia, to allow early recognition and consider pre-adaptation of crews to a hypoxic environment prior to launch; (3) consider prophylactic acetazolamide for acute pressure changes and be prepared to treat any AMS associated symptoms early with both carbonic anhydrase inhibitors and supplemental oxygen. Published by Elsevier Ltd.
C1 [Scheuring, Richard; Jones, Jeffrey A.; Gernhardt, Michael L.] NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA.
[Conkin, Johnny] Univ Space Res Assoc, Houston, TX 77058 USA.
RP Scheuring, R (reprint author), NASA, Lyndon B Johnson Space Ctr, 2101 NASA Pkwy SD4, Houston, TX 77058 USA.
EM richard.a.scheuring@nasa.gov
NR 61
TC 2
Z9 2
U1 1
U2 1
PU PERGAMON-ELSEVIER SCIENCE LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
SN 0094-5765
J9 ACTA ASTRONAUT
JI Acta Astronaut.
PD OCT-NOV
PY 2008
VL 63
IS 7-10
BP 727
EP 739
DI 10.1016/j.actaastro.2008.02.009
PG 13
WC Engineering, Aerospace
SC Engineering
GA 351FE
UT WOS:000259409100006
ER
PT J
AU Summers, R
Coleman, T
Meck, J
AF Summers, Richard
Coleman, Thomas
Meck, Janice
TI Development of the Digital Astronaut Project for the analysis of the
mechanisms of physiologic adaptation to microgravity: Validation of the
cardiovascular system module
SO ACTA ASTRONAUTICA
LA English
DT Article; Proceedings Paper
CT 16th IAA Humans in Space Symposium
CY MAY 20-24, 2007
CL Beijing, PEOPLES R CHINA
SP Int Acad Astronaut
DE Digital Astronaut; validation; computer model
ID POSTSPACEFLIGHT ORTHOSTATIC HYPOTENSION; SPACEFLIGHT-INDUCED CHANGES;
LEFT-VENTRICULAR MASS; CONFIDENCE-INTERVALS; FLIGHT; MODEL; BODY
AB The physiologic adaptation of humans to the microgravity environment is complex and requires an integrative perspective to fully understand the mechanisms involved. A large computer model of human systems physiology provides the framework for the development of the Digital Astronaut to be used by NASA in the analysis of adaptive mechanisms. While project expansion is ongoing to include all relevant systems, we describe the validation results of the cardiovascular phase of model development. The cardiovascular aspects of the model were validated by benchmark comparisons to published literature findings of changes in left ventricular mass, right atrial pressure and plasma volumes. Computer simulations using the model predicted microgravity induced changes in the target endpoints within statistical validity of experimental findings. Therefore, the current cardiovascular portion of the Digital Astronaut Project computer model appears to accurately predict observed microgravity induced physiologic adaptations. The ongoing process of model development to include all spaceflight relevant systems will require similar validations. Published by Elsevier Ltd.
C1 [Summers, Richard; Coleman, Thomas] Univ Mississippi, Med Ctr, Jackson, MS 39216 USA.
[Meck, Janice] NASA, Lyndon B Johnson Space Ctr, Human Adaptat & Countermeasures Off, Space & Life Sci Directorate, Houston, TX 77058 USA.
RP Summers, R (reprint author), Univ Mississippi, Med Ctr, 2500 N State St, Jackson, MS 39216 USA.
EM rsummers@pol.net
NR 23
TC 4
Z9 4
U1 4
U2 4
PU PERGAMON-ELSEVIER SCIENCE LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
SN 0094-5765
J9 ACTA ASTRONAUT
JI Acta Astronaut.
PD OCT-NOV
PY 2008
VL 63
IS 7-10
SI SI
BP 758
EP 762
DI 10.1016/j.actaastro.2007.12.054
PG 5
WC Engineering, Aerospace
SC Engineering
GA 351FE
UT WOS:000259409100009
ER
PT J
AU Jones, JA
Hoffman, RB
Buckland, DA
Harvey, CM
Bowen, CK
Hudy, CE
Strauss, S
Novak, J
Gernhardt, ML
AF Jones, J. A.
Hoffman, R. B.
Buckland, D. A.
Harvey, C. M.
Bowen, C. K.
Hudy, C. E.
Strauss, S.
Novak, J.
Gernhardt, M. L.
TI The use of an extended ventilation tube as a countermeasure for
EVA-associated upper extremity medical issues
SO ACTA ASTRONAUTICA
LA English
DT Article
CT 16th IAA Humans in Space Symposium
CY MAY 20-24, 2007
CL Beijing, PEOPLES R CHINA
SP Int Acad Astronaut
DE extravehicular activity (EVA); finger injury; onycholysis; ventilation
ID INJURIES
AB Introduction: Onycholysis due to repetitive activity in the space suit glove during Neutral Buoyancy Laboratory (NBL) training and during spaceflight extravehicular activity (EVA) is a common observation. Moisture accumulates in gloves during EVA task performance and may contribute to the development of pain and damage to the fingernails experienced by many astronauts. The study evaluated the use of a long ventilation tube to determine if improved gas circulation into the hand area could reduce hand moisture and thereby decrease the associated symptoms.
Methods: The current Extravehicular Mobility Unit (EMU) was configured with a ventilation tube that extended down a single arm of the crew member (E) and compared with the unventilated arm (C). Skin surface moisture was measured on both hands immediately after glove removal and a questionnaire administered to determine subjective measures. Astronauts (n = 6) were examined pre- and post-run.
Results: There were consistent trends in the reduction of relative hydration ratios at dorsum (C = 3.34, E = 2.11) and first ring. finger joint (C = 2.46, E = 1.96) when the ventilation tube was employed. Ventilation appeared more effective on the left versus the right hand, implying an interaction with hand anthropometry and glove fit. Symptom score was lower on the hand that had the long ventilation tube relative to the control hand in 2/6 EVA crew members.
Conclusions: Increased ventilation to the hand was effective in reducing the risks of hand and nail discomfort symptoms from moderate to low in one-third of the subjects. Improved design in the ventilation capability of EVA spacesuits is expected to improve efficiency of air flow distribution. Published by Elsevier Ltd.
C1 [Jones, J. A.; Gernhardt, M. L.] NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA.
[Jones, J. A.; Buckland, D. A.] NSBRI, Houston, TX USA.
[Hoffman, R. B.] MEI Technol, Houston, TX USA.
[Harvey, C. M.] Louisiana State Univ, Baton Rouge, LA 70803 USA.
[Bowen, C. K.; Hudy, C. E.] Lockheed Martin, Houston, TX USA.
[Buckland, D. A.] MIT, Harvard Mit Div Hlth Sci & Technol, Cambridge, MA 02139 USA.
[Strauss, S.] Kelsey Seybold, Houston, TX USA.
[Novak, J.] Univ Chicago, Chicago, IL 60637 USA.
RP Jones, JA (reprint author), NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA.
EM jeffrey.a.jones@nasa.gov
NR 5
TC 6
Z9 6
U1 0
U2 4
PU PERGAMON-ELSEVIER SCIENCE LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
SN 0094-5765
J9 ACTA ASTRONAUT
JI Acta Astronaut.
PD OCT-NOV
PY 2008
VL 63
IS 7-10
BP 763
EP 768
DI 10.1016/j.actaastro.2007.12.067
PG 6
WC Engineering, Aerospace
SC Engineering
GA 351FE
UT WOS:000259409100010
ER
PT J
AU Zhou, D
O'Sullivan, D
Semones, E
Zapp, N
Johnson, S
Weyland, M
AF Zhou, D.
O'Sullivan, D.
Semones, E.
Zapp, N.
Johnson, S.
Weyland, M.
TI Radiation dosimetry for high LET particles in low Earth orbit
SO ACTA ASTRONAUTICA
LA English
DT Article
CT 16th IAA Humans in Space Symposium
CY MAY 20-24, 2007
CL Beijing, PEOPLES R CHINA
SP Int Acad Astronaut
DE space radiation; CR-39 detectors; LET spectrum
ID NUCLEAR TRACK DETECTORS; CR-39 DETECTORS; COSMIC-RAYS; BULK ETCH
AB Research indicates that the impact to human tissues from radiation exposure is strongly related to the LET (linear energy transfer) of the particles and particles with high LET (>= 5 KeV/mu m water) dominate the damage. High LET radiation in LEO (low Earth orbit) is composed mainly of galactic cosmic rays (GCR), solar energetic particles, particles trapped in the SAA (South Atlantic Anomaly), and albedo neutrons and protons scattered from the Earth's atmosphere. So far the active personal dosimeters are not available and the best passive personal dosimeters currently applied to the radiation assessment for astronauts are CR-39 detectors (for the high LET part) in combination with thermoluminescence detectors (TLDs) or optically stimulated luminescence detectors) (OSLDs) (for the low LET part). LET spectra for radiation in LEO were determined with CR-39. This paper introduces the operational principles for CR-39 detectors, describes the method of LET spectrum using CR-39 and presents the results measured with CR-39 and TEPC (tissue equivalent proportional counter) for space mission ISS-Expedition 2, STS-108, STS-112, ISS-7S, STS-114 and STS-121. Published by Elsevier Ltd.
C1 [Zhou, D.; Semones, E.; Zapp, N.; Johnson, S.; Weyland, M.] Lyndon B Johnson Space Ctr, Houston, TX 77058 USA.
[Zhou, D.] Univ Space Res Assoc, Houston, TX 77058 USA.
[O'Sullivan, D.] Dublin Inst Adv Studies, Dublin 2, Ireland.
RP Zhou, D (reprint author), Lyndon B Johnson Space Ctr, Mailcode SF21,2101 Nasa Pkwy, Houston, TX 77058 USA.
EM dazhuang.zhou-1@nasa.gov
NR 24
TC 11
Z9 14
U1 0
U2 6
PU PERGAMON-ELSEVIER SCIENCE LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
SN 0094-5765
J9 ACTA ASTRONAUT
JI Acta Astronaut.
PD OCT-NOV
PY 2008
VL 63
IS 7-10
BP 855
EP 864
DI 10.1016/j.actaastro.2008.04.002
PG 10
WC Engineering, Aerospace
SC Engineering
GA 351FE
UT WOS:000259409100022
ER
PT J
AU Scheuring, RA
Jones, JA
Novak, JD
Polk, JD
Gillis, DB
Schmid, J
Duncan, JM
Davis, JR
AF Scheuring, Richard A.
Jones, Jeffrey A.
Novak, Joseph D.
Polk, James D.
Gillis, David B.
Schmid, Josef
Duncan, James M.
Davis, Jeffrey R.
TI The Apollo Medical Operations Project: Recommendations to improve crew
health and performance for future exploration missions and lunar surface
operations
SO ACTA ASTRONAUTICA
LA English
DT Article
CT 16th IAA Humans in Space Symposium
CY MAY 20-24, 2007
CL Beijing, PEOPLES R CHINA
SP Int Acad Astronaut
DE Apollo; lunar surface operations; Moon; EVA; astronauts
AB Introduction: Medical requirements for the future crew exploration vehicle (CEV), lunar surface access module (LSAM), advanced extravehicular activity (EVA) suits, and Lunar habitat are currently being developed within the exploration architecture. While much is known about the vehicle and lunar Surface activities during Apollo, relatively little is known about whether the hardware, systems, or environment impacted crew health or performance during these missions. Also, inherent to the proposed aggressive surface activities is the potential risk of injury to crewmembers. The Space Medicine Division at the NASA Johnson Space Center (JSC) requested a Study in December 2005 to identify Apollo mission issues relevant to medical operations impacting crew health and/or performance during a lunar mission. The goals of this project were to develop or modify medical requirements for new vehicles and habitats, create it centralized database for future access, and share relevant Apollo information with various working groups participating in the exploration effort.
Methods: A review of medical operations during Apollo missions 7-17 was conducted. Tell categories of hardware. systems. or crew factors were identified during preliminary data review generating 655 data records which were captured in an Access(R) database. The preliminary review resulted in 285 questions. The questions were posed to surviving Apollo crewmembers using mail, face-to-face meetings. phone communications, or online interactions.
Results: Fourteen of 22 surviving Apollo astronauts (64%) participated in (he project. This effort yielded 107 recommendations for future vehicles, habitats, EVA suits. and lunar surface operations.
Conclusions: To date, the Apollo Medical Operations recommendations are being incorporated into the exploration mission architecture at various levels and a centralized database has been developed. The Apollo crewmember's input has proved to be an invaluable resource. We will continue Soliciting input from this group as We Continue to evolve and refine requirements for the future exploration missions. Published by Elsevier Ltd.
C1 [Scheuring, Richard A.; Jones, Jeffrey A.; Polk, James D.; Gillis, David B.; Schmid, Josef; Duncan, James M.; Davis, Jeffrey R.] NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA.
[Novak, Joseph D.] Univ Chicago, Pritzker Sch Med, Chicago, IL 60637 USA.
RP Scheuring, RA (reprint author), NASA, Lyndon B Johnson Space Ctr, 2101 NASA Pkwy SD, Houston, TX 77058 USA.
EM richard.a.scheuring@nasa.gov
NR 12
TC 7
Z9 7
U1 1
U2 4
PU PERGAMON-ELSEVIER SCIENCE LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
SN 0094-5765
J9 ACTA ASTRONAUT
JI Acta Astronaut.
PD OCT-NOV
PY 2008
VL 63
IS 7-10
BP 980
EP 987
DI 10.1016/j.actaastro.2007.12.065
PG 8
WC Engineering, Aerospace
SC Engineering
GA 351FE
UT WOS:000259409100035
ER
PT J
AU Davis, JR
Fogarty, JA
Richard, EE
AF Davis, Jeffrey R.
Fogarty, Jennifer A.
Richard, Elizabeth E.
TI Human health and performance risk management - an approach for
exploration missions
SO ACTA ASTRONAUTICA
LA English
DT Article
CT 16th IAA Humans in Space Symposium
CY MAY 20-24, 2007
CL Beijing, PEOPLES R CHINA
SP Int Acad Astronaut
DE risk; standards; exploration missions; health; performance
AB During long duration exploration missions, maintaining human health and performance will be essential to enabling success. Therefore, NASA has developed standards through the Health and Medical Technical Authority to insure human health and performance during exploration. Human health standards are the first step in defining acceptable risk for human space flight and take into consideration both short-term (mission) and long-term (lifetime) health risk. These standards are based on the best medical evidence from terrestrial standards: analog spaceflight environments and spaceflight experience. Standards drive the development of focused program requirements to mitigate risks associated with specific missions. Program requirements include vehicle design as well as health care systems including medical, environmental and countermeasures. NASA has also developed the risk mitigation analysis tool (RMAT). a process to evaluate the effectiveness of risk mitigation strategies. The RMAT facilitates documentation and analysis of the effectiveness of mitigation strategies, enables NASA to baseline a risk mitigation approach based on the best evidence. and provides the traceability from research and technology development projects to specific mission deliverables. Published by Elsevier Ltd.
C1 [Davis, Jeffrey R.; Fogarty, Jennifer A.] NASA, Lyndon B Johnson Space Ctr, Space Life Sci Directorate, Houston, TX 77058 USA.
[Richard, Elizabeth E.] Wyle Life Sci, Houston, TX 77058 USA.
RP Fogarty, JA (reprint author), NASA, Lyndon B Johnson Space Ctr, Space Life Sci Directorate, 2101 NASA Pkwy, Houston, TX 77058 USA.
EM Jennifer.Fogarty-1@nasa.gov
NR 7
TC 5
Z9 5
U1 1
U2 1
PU PERGAMON-ELSEVIER SCIENCE LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
SN 0094-5765
J9 ACTA ASTRONAUT
JI Acta Astronaut.
PD OCT-NOV
PY 2008
VL 63
IS 7-10
BP 988
EP 995
DI 10.1016/j.actaastro.2008.02.004
PG 8
WC Engineering, Aerospace
SC Engineering
GA 351FE
UT WOS:000259409100036
ER
PT J
AU Khan-Mayberry, N
AF Khan-Mayberry, Noreen
TI The lunar environment: Determining the health effects of exposure to
moon dusts
SO ACTA ASTRONAUTICA
LA English
DT Article
CT 16th IAA Humans in Space Symposium
CY MAY 20-24, 2007
CL Beijing, PEOPLES R CHINA
SP Int Acad Astronaut
DE moon dust; lunar dust; health standards; health effects
AB The Earth's moon presents a hostile environment in which to live and work. There is no atmosphere to protect its surface from the ravages of cosmic radiation, solar wind and micrometeorite impacts. As a result. the moon's surface is covered with a thin layer of fine, charged, reactive dust capable of entering habitats, and vehicle compartments, where it can cause crew member health problems. During the Apollo missions, lunar dusts were introduced into the Lunar Lander and command module, resulting in direct exposure and occasional reports of respiratory. dermal and ocular irritation. Now that we are returning to the moon for long duration stays and multiple space walk exposures. NASA is concerned with the health of the astronauts in regards to repeated (chronic) and acute episodic exposures to lunar dusts. We expect that lunar dust will be returned to the module post-space-walk (extravehicular activity, EVA) activity. These repeated episodic exposures will need to be controlled by our Environmental Control Life Support System. based upon the health standards that we set for acute and chronic exposures.
In order to characterize the toxicological effects of lunar dust. NASA formed the Lunar Airborne Dust Toxicity Advisory Group (LADTAG). This interdisciplinary group is composed of experts in space toxicology, lunar geology, space medicine, dust toxicity. and biomedical research. Ultimately. this panel of experts will set health standards and risk criteria for use by vehicle design engineers, operation planners and astronauts during lunar missions. Published by Elsevier Ltd.
C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA.
RP Khan-Mayberry, N (reprint author), NASA, Lyndon B Johnson Space Ctr, 2101 NASA Pkwy,SF-23, Houston, TX 77058 USA.
EM noreen.n.khan-mayberry@nasa.gov
NR 17
TC 13
Z9 13
U1 2
U2 9
PU PERGAMON-ELSEVIER SCIENCE LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
SN 0094-5765
J9 ACTA ASTRONAUT
JI Acta Astronaut.
PD OCT-NOV
PY 2008
VL 63
IS 7-10
BP 1006
EP 1014
DI 10.1016/j.actaastro.2008.03.015
PG 9
WC Engineering, Aerospace
SC Engineering
GA 351FE
UT WOS:000259409100038
ER
PT J
AU Conley, CA
Rummel, JD
AF Conley, Catharine A.
Rummel, John D.
TI Planetary protection for humans in space: Mars and the Moon
SO ACTA ASTRONAUTICA
LA English
DT Article
CT 16th IAA Humans in Space Symposium
CY MAY 20-24, 2007
CL Beijing, PEOPLES R CHINA
SP Int Acad Astronaut
AB When searching for life beyond Earth, the unique capabilities provided by human astronauts will only be advantageous if the biological contamination associated with human presence is monitored and minimized. Controlling biological contamination during planetary exploration is termed 'planetary protection,' and will be a critical element in the human exploration of other solar system bodies. To ensure the safety and health of the astronauts and the Earth, while preserving science value, planetary protection considerations must be incorporated from the earliest stages of mission planning and development. Issues of concern to planetary protection involve both 'forward contamination,' which is the contamination of other solar system bodies by Earth microbes and organic materials, and 'backward contamination,' which is the contamination of Earth systems by potential alien life. Forward contamination concerns include contamination that might invalidate current or future scientific exploration of a particular solar system body, and that may disrupt the planetary environment or a potential endogenous (alien) ecosystem. Backward contamination concerns include both immediate and long-term effects on the health of the astronaut explorers from possible biologically active materials encountered during exploration, as well as the possible contamination of the Earth. A number of national and international workshops held over the last seven years have generated a consensus regarding planetary protection policies and requirements for human missions to Mars, and a 2007 workshop held by NASA has considered the issues and benefits to planetary protection that might be offered by a return to the Moon. Conclusions from these workshops recognize that some degree of forward contamination associated with human astronaut explorers is inevitable. Nonetheless. the principles and policies of planetary protection, developed by COSPAR in conformance with the 1967 Outer Space Treaty, can and should be followed when humans are exploring space. Implementation guidelines include documenting and minimizing contamination of the exploration targets, protection at the most stringent levels for any target locations in which Earth life might grow, protection of humans from exposure to untested planetary materials, and preventing harmful contamination of the Earth as the highest priority for all missions. These considerations should be incorporated in planning for future human exploration missions. Published by Elsevier Ltd.
C1 [Conley, Catharine A.; Rummel, John D.] NASA Headquarters, Sci Mission Directorate 3X63, Washington, DC 20546 USA.
RP Conley, CA (reprint author), NASA Headquarters, Sci Mission Directorate 3X63, Washington, DC 20546 USA.
EM cassie.conley@nasa.gov
NR 8
TC 1
Z9 1
U1 3
U2 6
PU PERGAMON-ELSEVIER SCIENCE LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
SN 0094-5765
J9 ACTA ASTRONAUT
JI Acta Astronaut.
PD OCT-NOV
PY 2008
VL 63
IS 7-10
BP 1025
EP 1030
DI 10.1016/j.actaastro.2008.03.012
PG 6
WC Engineering, Aerospace
SC Engineering
GA 351FE
UT WOS:000259409100040
ER
PT J
AU Duncan, JM
Bogomolov, VV
Castrucci, F
Koike, Y
Comtois, JM
Sargsyan, AE
AF Duncan, J. M.
Bogomolov, V. V.
Castrucci, F.
Koike, Y.
Comtois, J. M.
Sargsyan, A. E.
TI Organization and management of the International Space Station (ISS)
multilateral medical operations
SO ACTA ASTRONAUTICA
LA English
DT Article; Proceedings Paper
CT 16th IAA Humans in Space Symposium
CY MAY 20-24, 2007
CL Beijing, PEOPLES R CHINA
SP Int Acad Astronaut
DE aerospace medicine; space flight; spacecraft; weightlessness
countermeasure; certification; extraterrestrial environment;
international cooperation
ID CLINICAL ULTRASOUND ABOARD; FLIGHT
AB The goal of this work is to review the principles, design, and function of the ISS multilateral medical authority and the medical support system of the ISS Program. Multilateral boards and panels provide operational famework for. direct, and supervise the ISS joint medical operational activities. The integrated medical group (IMG) provides front-line medical Support of the crews. Results of ongoing activities are reviewed weekly by physician managers. A broader status review is conducted monthly to project the state of crew health and medical support for the following month. All boards, panels, and groups function effectively and without interruptions. Consensus prevails as the primary nature of decisions made by all ISS medical groups, including the ISS medical certification board. The sustained efforts of all partners have resulted in favorable medical outcomes of the initial 15 long-duration expeditions. The medical support system appears to be mature and ready for further expansion of the roles of all Partners, and for the anticipated increase in the size of ISS crews. (C) 2007 Elsevier Ltd. All rights reserved.
C1 [Sargsyan, A. E.] Wyle, Houston, TX 77058 USA.
[Duncan, J. M.] NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA.
[Bogomolov, V. V.] Russian Acad Sci, Inst Biomed Problems, State Res Ctr Russian Federat, Moscow 123007, Russia.
[Castrucci, F.] European Space Agcy, European Astronaut Ctr, D-51147 Cologne, Germany.
[Koike, Y.] Japan Aerosp Explorat Agcy, Tsukuba Space Ctr, Tsukuba, Ibaraki 3058505, Japan.
[Comtois, J. M.] Canadian Space Agcy, St Hubert, PQ J3Y 8Y9, Canada.
RP Sargsyan, AE (reprint author), Wyle, 1290 Hercules Dr,Ste 103, Houston, TX 77058 USA.
EM asargsyan@wylehou.com
NR 13
TC 5
Z9 6
U1 1
U2 3
PU PERGAMON-ELSEVIER SCIENCE LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
SN 0094-5765
J9 ACTA ASTRONAUT
JI Acta Astronaut.
PD OCT-NOV
PY 2008
VL 63
IS 7-10
SI SI
BP 1137
EP 1147
DI 10.1016/j.actaastro.2007.12.001
PG 11
WC Engineering, Aerospace
SC Engineering
GA 351FE
UT WOS:000259409100057
ER
PT J
AU Wu, DL
Schwartz, MJ
Waters, JW
Limpasuvan, V
Wu, QA
Killeen, TL
AF Wu, Dong L.
Schwartz, Michael J.
Waters, Joe W.
Limpasuvan, Varavut
Wu, Qian
Killeen, Timothy L.
TI Mesospheric doppler wind measurements from Aura Microwave Limb Sounder
(MLS)
SO ADVANCES IN SPACE RESEARCH
LA English
DT Article
DE Doppler wind; microwave radiometry; mesosphere tides; planetary waves
ID MIDDLE ATMOSPHERE; EOS MLS; IMAGER; INTERFEROMETER; VALIDATION;
SATELLITE; SPACE; TIDES; MODEL; UARS
AB This paper describes a microwave limb technique for measuring Doppler wind in the Earth's mesosphere. The research algorithm has been applied to Aura Microwave Limb Sounder (MLS) 118.75 GHz measurements where the 0, Zeeman lines are resolved by a digital autocorrelation spectrometer. A precision of similar to 17 m/s for the line-of-sight (LOS) wind is achieved at 80-92 km, which corresponds to radiometric noise during 1/6 s integration time. The LOS winds from Aura MLS are mostly in the meridional direction at low- and mid-latitudes with vertical resolution of similar to 8 km. This microwave Doppler technique has potential to obtain useful winds down to similar to 40 km of the Earth's atmosphere if measurements from other MLS frequencies (near H(2)O, O(3), and CO lines) are used. Initial analyses show that the MLS winds from the 118.75 GHz measurements agree well with the TIDI (Thermosphere Ionosphere Mesosphere Energetics and Dynamics Doppler Interferometer) winds for the perturbations induced by a strong quasi 2-day wave (QTDW) in January 2005. Time series of MLS winds reveal many interesting climatological and planetary wave features, including the diurnal, semidiurnal tides, and the QTDW. Interactions between the tides and the QTDW are clearly evident, indicating possible large tidal structural changes after the QTDW events dissipate. (C) 2007 COSPAR. Published by Elsevier Ltd. All rights reserved.
C1 [Wu, Dong L.; Schwartz, Michael J.; Waters, Joe W.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[Limpasuvan, Varavut] Coastal Carolina Univ, Dept Chem & Phys, Conway, SC 29528 USA.
[Wu, Qian; Killeen, Timothy L.] Natl Ctr Atmospher Res, High Altitude Observ, Boulder, CO 80303 USA.
RP Wu, DL (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM Dong.L.Wu@jpl.nasa-gov
RI Killeen, Timothy/F-2215-2013; Limpasuvan, Varavut/K-6266-2013; Schwartz,
Michael/F-5172-2016; Wu, Dong/D-5375-2012
OI Schwartz, Michael/0000-0001-6169-5094;
NR 18
TC 19
Z9 19
U1 0
U2 0
PU ELSEVIER SCI LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND
SN 0273-1177
J9 ADV SPACE RES
JI Adv. Space Res.
PD OCT 1
PY 2008
VL 42
IS 7
BP 1246
EP 1252
DI 10.1016/j.asr.2007.06.014
PG 7
WC Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology &
Atmospheric Sciences
SC Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences
GA 351HF
UT WOS:000259414600011
ER
PT J
AU Mahanama, SPP
Koster, RD
Reichle, RH
Zubair, L
AF Mahanama, Sarith P. P.
Koster, Randal D.
Reichle, Rolf H.
Zubair, Lareef
TI The role of soil moisture initialization in subseasonal and seasonal
streamflow prediction - A case study in Sri Lanka
SO ADVANCES IN WATER RESOURCES
LA English
DT Article
DE Soil moisture; Soil moisture initialization; Streamflow; Streamflow
prediction; Sri Lanka
ID LATITUDE HYDROLOGICAL PROCESSES; CATCHMENT-BASED APPROACH; WESTERN
UNITED-STATES; TORNE-KALIX BASIN; RIVER-BASIN; SURFACE PROCESSES; PILPS
PHASE-2(E); DATA SET; PREDICTABILITY; MEMORY
AB The two main contributors to streamflow predictability at subseasonal to seasonal timescales in tropical regions are: (i) the predictability of meteorologic (particularly precipitation) anomalies, and (ii) the land surface soil moisture state at the start of the forecast period. Meteorological predictions at subseasonal timescale are usually fraught with error and may not be dependable. The accurate initialization of soil moisture, as obtained through real-time land data analysis, may provide skill in subseasonal to seasonal streamflow prediction, even when the prediction skill for rainfall is small.
A series of experiments using the Catchment Land Surface Model (CLSM) is performed to characterize the contribution of accurate soil moisture initialization to the skill of streamflow prediction in Sri Lanka at timescales up to 2 months. We find that at the monthly timescale, accurate soil moisture initialization provides between 10% and 60% of the total runoff prediction skill that could be obtained under a perfect prediction of meteorological forcing. Some contributions to streamflow forecast skill are also found for the second month of forecast. (C) 2008 Elsevier Ltd. All rights reserved.
C1 [Mahanama, Sarith P. P.; Koster, Randal D.; Reichle, Rolf H.] NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Greenbelt, MD 20771 USA.
[Mahanama, Sarith P. P.; Reichle, Rolf H.] Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21250 USA.
[Zubair, Lareef] Columbia Univ, Int Res Inst Climate & Soc, Earth Inst, Palisades, NY 10964 USA.
RP Mahanama, SPP (reprint author), NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Mail Stop 610-1, Greenbelt, MD 20771 USA.
EM Sarith.P.Mahanama@nasa.gov; Randal.D.Koster@nasa.gov;
Rolf.H.Reichle@nasa.gov; lareef@iri.columbia.edu
RI Reichle, Rolf/E-1419-2012; Koster, Randal/F-5881-2012
OI Koster, Randal/0000-0001-6418-6383
NR 34
TC 22
Z9 22
U1 0
U2 7
PU ELSEVIER SCI LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND
SN 0309-1708
EI 1872-9657
J9 ADV WATER RESOUR
JI Adv. Water Resour.
PD OCT
PY 2008
VL 31
IS 10
BP 1333
EP 1343
DI 10.1016/j.advwatres.2008.06.004
PG 11
WC Water Resources
SC Water Resources
GA 363TW
UT WOS:000260290800006
ER
PT J
AU Lowman, PD
Sharpe, BL
Schrunk, DG
AF Lowman, Paul D., Jr.
Sharpe, Burton L.
Schrunk, David G.
TI MOONBASE MONS MALAPERT? MAKING THE CASE
SO AEROSPACE AMERICA
LA English
DT Article
C1 [Lowman, Paul D., Jr.] NASA Goddard, Greenbelt, MD 20771 USA.
RP Lowman, PD (reprint author), NASA Goddard, Greenbelt, MD 20771 USA.
NR 0
TC 0
Z9 0
U1 1
U2 1
PU AMER INST AERONAUT ASTRONAUT
PI RESTON
PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA
SN 0740-722X
J9 AEROSPACE AM
JI Aerosp. Am.
PD OCT
PY 2008
VL 46
IS 10
BP 38
EP 43
PG 6
WC Engineering, Aerospace
SC Engineering
GA 360NC
UT WOS:000260063200013
ER
PT J
AU Driver, DM
Drake, A
AF Driver, David M.
Drake, Aaron
TI Skin-Friction Measurements Using Oil-Film Interferometry in NASA's
11-Foot Transonic Wind Tunnel
SO AIAA JOURNAL
LA English
DT Article; Proceedings Paper
CT AIAA 42nd Aerospace Sciences Meeting and Exhibit
CY JAN 05-08, 2004
CL Reno, NV
SP Amer Inst Aeronaut & Astronaut
AB Skin-friction measurements were obtained on two laminar flow airfoils in the NASA Ames 11-ft transonic wind tunnel using oil-film interferometry. Improvements in the experimental technique allowed skin-friction measurements at two conditions per run in conjunction with performance testing, thus reducing the impact on the run schedule. Quantitative measurements of skin friction were used to determine transition location and the extent of separation (if any) on the airfoils providing much more insight into the flow than flow viz. The technique has been extended to obtain a quantitative measure of shear in the reversed flow region. The effects of various disturbances to the boundary layer were also investigated. Laminar How was found as far back as 60% chord at a Reynolds number of 4.5 x 10(6).
C1 [Driver, David M.] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
[Drake, Aaron] Northrop Grumman Corp, El Segundo, CA 90245 USA.
RP Driver, DM (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
EM David.M.Driver@nasa.gov; Aaron.Drake@ngc.com
NR 14
TC 3
Z9 3
U1 1
U2 3
PU AMER INST AERONAUT ASTRONAUT
PI RESTON
PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA
SN 0001-1452
J9 AIAA J
JI AIAA J.
PD OCT
PY 2008
VL 46
IS 10
BP 2401
EP 2407
DI 10.2514/1.7570
PG 7
WC Engineering, Aerospace
SC Engineering
GA 358GZ
UT WOS:000259906400001
ER
PT J
AU Turner, TL
Cabell, RH
Cano, RJ
Silcox, RJ
AF Turner, Travis L.
Cabell, Randolph H.
Cano, Roberto J.
Silcox, Richard J.
TI Development of a Preliminary Model-Scale Adaptive Jet Engine Chevron
SO AIAA JOURNAL
LA English
DT Article
ID HYBRID COMPOSITES; SHAPE CONTROL; FABRICATION; ACTUATION; BEAMS
AB Reduction of jet noise continues to be an important research topic. Exbaust-nozzle chevrons have been shown to reduce jet noise, but parametric effects, including immersion amount and azimuthal distribution, are not well understood. Additionally, thrust loss due to static chevrons at cruise suggests a significant benefit from deployable chevrons. The focus of this study is the development of an adaptive-chevron concept for the primary purpose of parametric studies for jet noise reduction in the laboratory and secondarily for development of technology that can be leveraged for full-scale systems. The adaptive-chevron concept employed in this work consists of a laminated composite structure with embedded shape memory alloy actuators. The actuators are embedded on one side of the middle surface such that joule heating of the actuators causes them to attempt recovery of prestrain, thereby generating a moment and deflecting the structure. A brief description of the chevron design is given followed by details of the fabrication approach. Results from bench-top tests are presented and correlated with numerical predictions from a model for such structures that was previously implemented in MSC.Nastran and ABAQUS. Excellent performance and agreement with predictions is demonstrated. Results from tests in a representative flow environment are also presented. Excellent performance is again achieved for both open- and closed-loop tests, the latter demonstrating control of deflection to a specified immersion into the flow. The actuation authority and immersion performance is shown to be relatively insensitive to nozzle pressure ratio. Very repeatable immersion control with modest power requirements is demonstrated.
C1 [Turner, Travis L.; Cabell, Randolph H.; Cano, Roberto J.; Silcox, Richard J.] NASA, Langley Res Ctr, Struct Acoust Branch, Hampton, VA 23681 USA.
RP Turner, TL (reprint author), NASA, Langley Res Ctr, Struct Acoust Branch, Bldg 1208,Room 110,Mail Stop 463, Hampton, VA 23681 USA.
EM t.l.turner@nasa.gov
NR 30
TC 4
Z9 5
U1 0
U2 0
PU AMER INST AERONAUTICS ASTRONAUTICS
PI RESTON
PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA
SN 0001-1452
EI 1533-385X
J9 AIAA J
JI AIAA J.
PD OCT
PY 2008
VL 46
IS 10
BP 2545
EP 2557
DI 10.2514/1.35939
PG 13
WC Engineering, Aerospace
SC Engineering
GA 358GZ
UT WOS:000259906400014
ER
PT J
AU McNamara, JJ
Friedmann, PP
Powell, KG
Thuruthimattam, BJ
Bartels, RE
AF McNamara, Jack J.
Friedmann, Peretz P.
Powell, Kenneth G.
Thuruthimattam, Biju J.
Bartels, Robert E.
TI Aeroelastic and Aerothermoelastic Behavior in Hypersonic Flow
SO AIAA JOURNAL
LA English
DT Article
ID FLUTTER-BOUNDARY; WINGS; AIRCRAFT; SYSTEMS; PLATES; MESH
AB The testing of aeroelastically and aerothermoelastically scaled wind-tunnel models in hypersonic flow is not feasible; thus, computational aeroelasticity and aerothermoelasticity are essential to the development of hypersonic vehicles. Several fundamental issues in this area are examined by performing a systematic computational study of the hypersonic aeroelastic and aerothermoelastic behavior of a three-dimensional configuration. Specifically, the flutter boundary of a low-aspect-ratio wing, representative of a fin or control surface on a hypersonic vehicle, is studied over a range of altitudes using third-order piston theory and Euler and Navier-Stokes aerodynamics. The sensitivity of the computational-fluid-dynamics-based aeroelastic analysis to grid resolution and parameters governing temporal accuracy are considered. In general, good agreement at moderate-to-high altitudes was observed for the three aerodynamic models. However, the wing flutters at unrealistic Mach numbers in the absence of aerodynamic heating. Therefore, because aerodynamic heating is an inherent feature of hypersonic flight and the aeroelastic behavior of a vehicle is sensitive to structural variations caused by heating, all aerothermoelastic methodology is developed that incorporates the heat transfer between the fluid and structure based on computdtional-fluid-dynamics-generated aerodynamic heating. The aerothermoelastic solution procedure is then applied to the low-aspect-ratio wing operating on a representative hypersonic trajectory. In the latter study, the sensitivity of the flutter margin to perturbations in trajectory angle of attack and Mach number is considered. Significant reductions in the flutter boundary of the heated wing are observed. The wing is also found to be susceptible to thermal buckling.
C1 [McNamara, Jack J.; Friedmann, Peretz P.; Powell, Kenneth G.; Thuruthimattam, Biju J.] Univ Michigan, Dept Aerosp Engn, Ann Arbor, MI 48109 USA.
[Bartels, Robert E.] NASA, Langley Res Ctr, Aeroelastic Branch, Hampton, VA 23681 USA.
RP McNamara, JJ (reprint author), Ohio State Univ, Dept Aerosp Engn, Columbus, OH 43210 USA.
OI Powell, Kenneth/0000-0002-3708-8814
FU Space Vehicle Technology Institute [NCC3-989]; NASA; U.S. Department of
Defense; U.S. Air Force [F49620-01-0158]
FX This research was partially funded by the Space Vehicle Technology
Institute under grant NCC3-989, jointly funded by NASA and the U.S.
Department of Defense within the NASA Constellation University
Institutes Project, with Claudia Meyer as the project manager, and U.S.
Air Force grant F49620-01-0158, with Clark Allred as program manager.
The authors wish to express their gratitude to NASA Langley Research
Center for the CFL3D code.
NR 84
TC 29
Z9 34
U1 3
U2 34
PU AMER INST AERONAUT ASTRONAUT
PI RESTON
PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA
SN 0001-1452
J9 AIAA J
JI AIAA J.
PD OCT
PY 2008
VL 46
IS 10
BP 2591
EP 2610
DI 10.2514/1.36711
PG 20
WC Engineering, Aerospace
SC Engineering
GA 358GZ
UT WOS:000259906400018
ER
PT J
AU Shvedova, AA
Kisin, E
Murray, AR
Johnson, VJ
Gorelik, O
Arepalli, S
Hubbs, AF
Mercer, RR
Keohavong, P
Sussman, N
Jin, J
Yin, J
Stone, S
Chen, BT
Deye, G
Maynard, A
Castranova, V
Baron, PA
Kagan, VE
AF Shvedova, A. A.
Kisin, E.
Murray, A. R.
Johnson, V. J.
Gorelik, O.
Arepalli, S.
Hubbs, A. F.
Mercer, R. R.
Keohavong, P.
Sussman, N.
Jin, J.
Yin, J.
Stone, S.
Chen, B. T.
Deye, G.
Maynard, A.
Castranova, V.
Baron, P. A.
Kagan, V. E.
TI Inhalation vs. aspiration of single-walled carbon nanotubes in C57BL/6
mice: inflammation, fibrosis, oxidative stress, and mutagenesis
SO AMERICAN JOURNAL OF PHYSIOLOGY-LUNG CELLULAR AND MOLECULAR PHYSIOLOGY
LA English
DT Article
DE nanoparticles; lung disease
ID INTRATRACHEAL INSTILLATION; LUNG-TUMORS; PULMONARY INFLAMMATION; MOUSE
LUNG; IN-VITRO; TOXICITY; EXPOSURE; CANCER; PARTICLES; RATS
AB Shvedova AA, Kisin E, Murray AR, Johnson VJ, Gorelik O, Arepalli S, Hubbs AF, Mercer RR, Keohavong P, Sussman N, Jin J, Yin J, Stone S, Chen BT, Deye G, Maynard A, Castranova V, Baron PA, Kagan VE. Inhalation vs. aspiration of single-walled carbon nanotubes in C57BL/6 mice: inflammation, fibrosis, oxidative stress, and mutagenesis. Am J Physiol Lung Cell Mol Physiol 295: L552-L565, 2008. First published July 25, 2008; doi: 10.1152/ajplung.90287.2008.-Nanomaterials are frontier technological products used in different manufactured goods. Because of their unique physicochemical, electrical, mechanical, and thermal properties, single-walled carbon nanotubes (SWCNT) are finding numerous applications in electronics, aerospace devices, computers, and chemical, polymer, and pharmaceutical industries. SWCNT are relatively recently discovered members of the carbon allotropes that are similar in structure to fullerenes and graphite. Previously, we ( 47) have reported that pharyngeal aspiration of purified SWCNT by C57BL/6 mice caused dose-dependent granulomatous pneumonia, oxidative stress, acute inflammatory/cytokine responses, fibrosis, and decrease in pulmonary function. To avoid potential artifactual effects due to instillation/agglomeration associated with SWCNT, we conducted inhalation exposures using stable and uniform SWCNT dispersions obtained by a newly developed aerosolization technique ( 2). The inhalation of nonpurified SWCNT ( iron content of 17.7% by weight) at 5 mg/m(3), 5 h/day for 4 days was compared with pharyngeal aspiration of varying doses (5-20 mu g per mouse) of the same SWCNT. The chain of pathological events in both exposure routes was realized through synergized interactions of early inflammatory response and oxidative stress culminating in the development of multifocal granulomatous pneumonia and interstitial fibrosis. SWCNT inhalation was more effective than aspiration in causing inflammatory response, oxidative stress, collagen deposition, and fibrosis as well as mutations of K-ras gene locus in the lung of C57BL/6 mice.
C1 [Shvedova, A. A.; Kisin, E.; Murray, A. R.; Hubbs, A. F.; Mercer, R. R.; Stone, S.; Chen, B. T.; Castranova, V.] NIOSH, Pathol & Physiol Res Branch, Hlth Effects Lab Div, Morgantown, WV 26505 USA.
[Johnson, V. J.] NIOSH, Toxicol & Mol Biol Branch, Hlth Effects Lab Div, Morgantown, WV 26505 USA.
[Shvedova, A. A.; Mercer, R. R.; Castranova, V.] W Virginia Univ, Morgantown, WV 26506 USA.
[Gorelik, O.; Arepalli, S.] Lockheed Martin, Engn Directorate, Mat & Proc Branch, Houston, TX USA.
[Gorelik, O.; Arepalli, S.] NASA, Lyndon B Johnson Space Ctr, GB Tech, Nanotube Team, Houston, TX 77058 USA.
[Deye, G.; Baron, P. A.] NIOSH, Monitoring Res & Stat Act, Div Appl Res & Technol, Morgantown, WV 26505 USA.
[Maynard, A.] Woodrow Wilson Int Ctr Scholars, Washington, DC 20560 USA.
[Keohavong, P.; Sussman, N.; Jin, J.; Yin, J.; Castranova, V.; Kagan, V. E.] Univ Pittsburgh, Dept Environm & Occupat Hlth, Pittsburgh, PA USA.
RP Shvedova, AA (reprint author), NIOSH, Pathol & Physiol Res Branch, Hlth Effects Lab Div, Morgantown, WV 26505 USA.
EM ats1@cdc.gov
RI Johnson, Victor/A-7910-2009; Arepalli, Sivaram/A-5372-2010; Maynard,
Andrew/D-1076-2010;
OI Keohavong, Phouthone/0000-0001-7812-4925; Maynard,
Andrew/0000-0003-2117-5128
FU NIOSH [OH008282]; National Heart, Lung, and Blood Institute [HL-70755];
National Occupational Research Agenda [927000Y]; European Commission
FX This study was supported by NIOSH Grant OH008282, National Heart, Lung,
and Blood Institute Grant HL-70755, National Occupational Research
Agenda Grant 927000Y, and the 7th Framework Program of the European
Commission.
NR 54
TC 336
Z9 341
U1 5
U2 59
PU AMER PHYSIOLOGICAL SOC
PI BETHESDA
PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 USA
SN 1040-0605
J9 AM J PHYSIOL-LUNG C
JI Am. J. Physiol.-Lung Cell. Mol. Physiol.
PD OCT
PY 2008
VL 295
IS 4
BP L552
EP L565
DI 10.1152/ajplung.90287.2008
PG 14
WC Physiology; Respiratory System
SC Physiology; Respiratory System
GA 367EH
UT WOS:000260534800003
PM 18658273
ER
PT J
AU Doran, PT
Mckay, CP
Fountain, AG
Nylen, T
Mcknight, DM
Jaros, C
Barrett, JE
AF Doran, Peter T.
McKay, Christopher P.
Fountain, Andrew G.
Nylen, Thomas
Mcknight, Diane M.
Jaros, Chris
Barrett, John E.
TI Hydrologic response to extreme warm and cold summers in the McMurdo Dry
Valleys, East Antarctica
SO ANTARCTIC SCIENCE
LA English
DT Article
DE climate; glaciers; hydrology; lakes; palaeoclimate; streams
ID LAST GLACIAL MAXIMUM; GROUNDED ICE-SHEET; TAYLOR VALLEY; ROSS SEA; LAKE
BONNEY; CLIMATE-CHANGE; HOLOCENE; TEMPERATURES; CHRONOLOGY; VICTORIA
AB The meteorological characteristics and hydrological response of an extreme warm, and cold summer in the McMurdo Dry Valleys are compared. The driver behind the warmer summer conditions was the occurrence of down-valley winds, which were not present during the colder summer. Occurrence of the summer down-valley winds coincided with lower than typical mean sea level pressure in the Ross Sea region. There was no significant difference in the amount of solar radiation received during the two summers. Compared to the cold summer, glaciological and hydrological response to the warm summer in Taylor Valley included significant glacier mass loss, and 3- to nearly 6000-fold increase in annual streamflow. Lake levels decreased slightly during the cold summer, and increased between 0.54 and 1.01 m during the warm summer, effectively erasing the prior 14 years of lake level lowering in a period of three months. Lake level rise during the warm summer was shown to be strongly associated with and increase in degree days above freezing at higher elevations. We suggest that strong summer down-valley winds may have been responsible for the generation of large glacial lakes during the Last Glacial Maximum when ice core records recorded annual temperatures significantly colder than present.
C1 [Doran, Peter T.] Univ Illinois, Chicago, IL 60607 USA.
[McKay, Christopher P.] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
[Fountain, Andrew G.; Nylen, Thomas] Portland State Univ, Dept Geol, Portland, OR 97207 USA.
[Mcknight, Diane M.; Jaros, Chris] Univ Colorado, Inst Arctic & Alpine Res, Boulder, CO 80309 USA.
[Barrett, John E.] Virginia Polytech Inst & State Univ, Dept Biol Sci, Blacksburg, VA 24061 USA.
RP Doran, PT (reprint author), Univ Illinois, Chicago, IL 60607 USA.
EM pdoran@uic.edu
RI Barrett, John/D-5851-2016;
OI Barrett, John/0000-0002-7610-0505; MCKNIGHT, DIANE/0000-0002-4171-1533
FU National Science Foundation [OPP9211773, OPP9813061, OPP9810219,
OPP0096250]
FX This research was supported by the National Science Foundation
(OPP9211773, OPP9813061, OPP9810219, OPP0096250). We thank Trevor Chinn
for Supplying us with historical lake level measurements.
NR 28
TC 75
Z9 75
U1 2
U2 23
PU CAMBRIDGE UNIV PRESS
PI NEW YORK
PA 32 AVENUE OF THE AMERICAS, NEW YORK, NY 10013-2473 USA
SN 0954-1020
J9 ANTARCT SCI
JI Antarct. Sci.
PD OCT
PY 2008
VL 20
IS 5
BP 499
EP 509
DI 10.1017/S0954102008001272
PG 11
WC Environmental Sciences; Geography, Physical; Geosciences,
Multidisciplinary
SC Environmental Sciences & Ecology; Physical Geography; Geology
GA 360ML
UT WOS:000260061500011
ER
PT J
AU Bhartia, R
Hug, WF
Salas, EC
Reid, RD
Sijapati, KK
Tsapin, A
Abbey, W
Nealson, KH
Lane, AL
Conrad, PG
AF Bhartia, Rohit
Hug, Willam F.
Salas, Everett C.
Reid, Ray D.
Sijapati, Kripa K.
Tsapin, Alexandre
Abbey, William
Nealson, Kenneth H.
Lane, Arthur L.
Conrad, Pamela G.
TI Classification of Organic and Biological Materials with Deep Ultraviolet
Excitation
SO APPLIED SPECTROSCOPY
LA English
DT Article
DE Native fluorescence; Deep ultraviolet; Principal component analysis; PCA
ID PRINCIPAL COMPONENT ANALYSIS; SUBTILIS SPORE COAT; INTRINSIC
FLUORESCENCE; RESONANCE RAMAN; CAPILLARY-ELECTROPHORESIS; ATMOSPHERIC
AEROSOL; MASS-SPECTROMETRY; LASER; IDENTIFICATION; SPECTROSCOPY
AB We show that native fluorescence can be used to differentiate classes or groups of organic molecules and biological materials when excitation occurs at specific excitation wavelengths in the deep ultraviolet (UV) region. Native fluorescence excitation-emission maps (EEMs) of pure organic materials, microbiological samples, and environmental background materials were compared using excitation wavelengths between 200-400 nm with emission wavelengths from 270 to 500 mn. These samples included polycyclic aromatic hydrocarbons (PAHs), nitrogen- and sulfur-bearing organic heterocycles, bacterial spores, and bacterial vegetative whole cells (both Gram positive and Gram negative). Each sample was categorized into ten distinct groups based on fluorescence properties. Emission spectra at each of 40 excitation wavelengths were analyzed using principal component analysis (PCA). Optimum excitation wavelengths for differentiating groups were determined using two metrics. We show that deep UV excitation at 235 (+/- 2) nm optimally separates all organic and biological groups within our dataset with > 90% confidence. For the specific case of separation of bacterial spores from all other samples in the database, excitation at wavelengths less than 250 nm provides maximum separation with > 6 sigma confidence.
C1 [Bhartia, Rohit; Tsapin, Alexandre; Abbey, William; Lane, Arthur L.; Conrad, Pamela G.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[Hug, Willam F.; Reid, Ray D.; Sijapati, Kripa K.] Photon Syst Inc, Covina, CA 91722 USA.
[Salas, Everett C.; Nealson, Kenneth H.] Univ So Calif, Dept Earth Sci, Los Angeles, CA 90089 USA.
RP Bhartia, R (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM rbhartia@jpl.nasa.gov
FU internal Jet Propulsion Laboratory; National Aeronautics Space
Administration's Astrobiology Technology and Exploration Program
(ASTEP); Astrobiology Technology and Instrument Development Program
(ASTID); Planetary Protection Research Program (PPR); ARMY Research,
Development and Engineering Command (RDEC) STTR
FX The authors would like to thank Drs. Michael Storrie-Lombardi, Gene
McDonald, Michael Pelletier, and Richard Kidd for helpful discussions
about native fluorescence and the analytical methods used. This research
was carried out at the Jet Propulsion Laboratory, Caltech Institute of
Technology, under a contract with the National Aeronautics and Space
Administration. The work was funded by internal Jet Propulsion
Laboratory research funds, National Aeronautics Space Administration's
Astrobiology Technology and Exploration Program (ASTEP), Astrobiology
Technology and Instrument Development Program (ASTID), Planetary
Protection Research Program (PPR), and ARMY Research, Development and
Engineering Command (RDEC) STTR research funds.
NR 50
TC 23
Z9 23
U1 1
U2 23
PU SOC APPLIED SPECTROSCOPY
PI FREDERICK
PA 201B BROADWAY ST, FREDERICK, MD 21701 USA
SN 0003-7028
J9 APPL SPECTROSC
JI Appl. Spectrosc.
PD OCT
PY 2008
VL 62
IS 10
BP 1070
EP 1077
PG 8
WC Instruments & Instrumentation; Spectroscopy
SC Instruments & Instrumentation; Spectroscopy
GA 359YM
UT WOS:000260024200004
PM 18926014
ER
PT J
AU Lunine, JI
Fischer, D
Hammel, HB
Henning, T
Hillenbrand, L
Kasting, J
Laughlin, G
Macintosh, B
Marley, M
Melnick, G
Monet, D
Noecker, C
Peale, S
Quirrenbach, A
Seager, S
Winn, JN
AF Lunine, Jonathan I.
Fischer, Debra
Hammel, H. B.
Henning, Thomas
Hillenbrand, Lynne
Kasting, James
Laughlin, Greg
Macintosh, Bruce
Marley, Mark
Melnick, Gary
Monet, David
Noecker, Charley
Peale, Stan
Quirrenbach, Andreas
Seager, Sara
Winn, Joshua N.
TI Worlds Beyond: A Strategy for the Detection and Characterization of
Exoplanets Executive Summary of a Report of the ExoPlanet Task Force
Astronomy and Astrophysics Advisory Committee Washington, DC June 23,
2008
SO ASTROBIOLOGY
LA English
DT Editorial Material
C1 [Lunine, Jonathan I.] Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA.
[Fischer, Debra] San Francisco State Univ, San Francisco, CA 94132 USA.
[Hammel, H. B.] Space Sci Inst, Boulder, CO USA.
[Henning, Thomas] Max Planck Inst, Heidelberg, Germany.
[Hillenbrand, Lynne] CALTECH, Pasadena, CA 91125 USA.
[Kasting, James] Penn State Univ, University Pk, PA 16802 USA.
[Laughlin, Greg] Univ Calif Santa Cruz, Santa Cruz, CA 95064 USA.
[Macintosh, Bruce] Lawrence Livermore Labs, Livermore, CA USA.
[Marley, Mark] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
[Melnick, Gary] Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA.
[Monet, David] US Naval Observ, Flagstaff, AZ USA.
[Noecker, Charley] Ball Aerosp & Technol Corp, Boulder, CO USA.
[Peale, Stan] Univ Calif Santa Barbara, Santa Barbara, CA 93106 USA.
[Quirrenbach, Andreas] Landessternwarte Heidelberg, Heidelberg, Germany.
[Seager, Sara; Winn, Joshua N.] MIT, Cambridge, MA 02139 USA.
RP Lunine, JI (reprint author), Univ Arizona, Lunar & Planetary Lab, 1629 E Univ Blvd, Tucson, AZ 85721 USA.
EM jlunine@lpl.arizona.edu
RI Marley, Mark/I-4704-2013;
OI Fischer, Debra/0000-0003-2221-0861
NR 0
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PA 140 HUGUENOT STREET, 3RD FL, NEW ROCHELLE, NY 10801 USA
SN 1531-1074
J9 ASTROBIOLOGY
JI Astrobiology
PD OCT
PY 2008
VL 8
IS 5
BP 875
EP 881
DI 10.1089/ast.2008.0276
PG 7
WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary
SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics;
Geology
GA 391RJ
UT WOS:000262250100001
PM 18800860
ER
PT J
AU Ohmoto, H
Runnegar, B
Kump, LR
Fogel, ML
Kamber, B
Anbar, AD
Knauth, PL
Lowe, DR
Sumner, DY
Watanabe, Y
AF Ohmoto, Hiroshi
Runnegar, Bruce
Kump, Lee R.
Fogel, Marilyn L.
Kamber, Balz
Anbar, Ariel D.
Knauth, Paul L.
Lowe, Donald R.
Sumner, Dawn Y.
Watanabe, Yumiko
TI Biosignatures in Ancient Rocks: A Summary of Discussions at a Field
Workshop on Biosignatures in Ancient Rocks
SO ASTROBIOLOGY
LA English
DT Editorial Material
ID BILLION YEARS AGO; GREAT OXIDATION EVENT; MASS-DEPENDENT FRACTIONATION;
PROTEROZOIC OCEAN CHEMISTRY; SULFUR ISOTOPE EVIDENCE; ATMOSPHERIC
OXYGEN; WESTERN-AUSTRALIA; MULTIPLE-SULFUR; TRACE-ELEMENT; SOUTH-AFRICA
C1 [Ohmoto, Hiroshi; Kump, Lee R.; Watanabe, Yumiko] Penn State Univ, NASA, Astrobiol Inst, University Pk, PA 16802 USA.
[Ohmoto, Hiroshi; Kump, Lee R.; Watanabe, Yumiko] Penn State Univ, Dept Geosci, University Pk, PA 16802 USA.
[Runnegar, Bruce] Univ Calif Los Angeles, NASA, Astrobiol Inst, Los Angeles, CA USA.
[Runnegar, Bruce] Univ Calif Los Angeles, Dept Earth & Space Sci, Los Angeles, CA USA.
[Fogel, Marilyn L.] NASA, Astrobiol Inst, Washington, DC 20546 USA.
[Fogel, Marilyn L.] Carnegie Inst Washington, Geophys Lab, Washington, DC 20015 USA.
[Kamber, Balz] Laurentian Univ, Dept Earth Sci, Sudbury, ON P3E 2C6, Canada.
[Anbar, Ariel D.; Knauth, Paul L.] Arizona State Univ, Sch Earth & Space Explorat, Tempe, AZ USA.
[Lowe, Donald R.] Stanford Univ, Sch Earth Sci, Dept Geol & Environm Sci, Stanford, CA 94305 USA.
[Sumner, Dawn Y.] Univ Calif Davis, Dept Geol, Davis, CA 95616 USA.
RP Ohmoto, H (reprint author), Penn State Univ, NASA, Astrobiol Inst, 435 Deike Bldg, University Pk, PA 16802 USA.
EM ohmoto@geosc.psu.edu
RI Kamber, Balz/A-1823-2008; Sumner, Dawn/E-8744-2011; Kump,
Lee/H-8287-2012; Fogel, Marilyn/M-2395-2015
OI Kamber, Balz/0000-0002-8720-0608; Sumner, Dawn/0000-0002-7343-2061;
Fogel, Marilyn/0000-0002-1176-3818
NR 113
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SN 1531-1074
J9 ASTROBIOLOGY
JI Astrobiology
PD OCT
PY 2008
VL 8
IS 5
BP 883
EP 895
DI 10.1089/ast.2008.0257
PG 13
WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary
SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics;
Geology
GA 391RJ
UT WOS:000262250100002
PM 19025466
ER
PT J
AU McKay, CP
Porco, CC
Altheide, T
Davis, WL
Kral, TA
AF McKay, Christopher P.
Porco, Carolyn C.
Altheide, Travis
Davis, Wanda L.
Kral, Timothy A.
TI The Possible Origin and Persistence of Life on Enceladus and Detection
of Biomarkers in the Plume
SO ASTROBIOLOGY
LA English
DT Article
DE Life; Enceladus; Biomarkers; Methanogens; Non-methane hydrocarbons;
Ammonia; Origin of life
ID HYDROTHERMAL SYSTEMS; HYDROCARBON PRODUCTION; ORGANIC-MOLECULES; EARLY
EARTH; METHANE; METHANOGENESIS; AMMONIA; MARS; SUBSURFACE; EUROPA
AB The jets of icy particles and water vapor issuing from the south pole of Enceladus are evidence for activity driven by some geophysical energy source. The vapor has also been shown to contain simple organic compounds, and the south polar terrain is bathed in excess heat coming from below. The source of the ice and vapor, and the mechanisms that accelerate the material into space, remain obscure. However, it is possible that a liquid water environment exists beneath the south polar cap, which may be conducive to life. Several theories for the origin of life on Earth would apply to Enceladus. These are (1) origin in an organic-rich mixture, (2) origin in the redox gradient of a submarine vent, and (3) panspermia. There are three microbial ecosystems on Earth that do not rely on sunlight, oxygen, or organics produced at the surface and, thus, provide analogues for possible ecologies on Enceladus. Two of these ecosystems are found deep in volcanic rock, and the primary productivity is based on the consumption by methanogens of hydrogen produced by rock reactions with water. The third ecosystem is found deep below the surface in South Africa and is based on sulfur-reducing bacteria consuming hydrogen and sulfate, both of which are ultimately produced by radioactive decay. Methane has been detected in the plume of Enceladus and may be biological in origin. An indicator of biological origin may be the ratio of non-methane hydrocarbons to methane, which is very low (0.001) for biological sources but is higher (0.1-0.01) for nonbiological sources. Thus, Cassini's instruments may detect plausible evidence for life by analysis of hydrocarbons in the plume during close encounters.
C1 [McKay, Christopher P.; Davis, Wanda L.] NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA.
[Porco, Carolyn C.] Space Sci Inst, Cassini Imaging Cent Lab Operat, Boulder, CO USA.
[Altheide, Travis; Kral, Timothy A.] Univ Arkansas, Dept Biol Sci, Fayetteville, AR 72701 USA.
RP Mckay, CP (reprint author), NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA.
EM christopher.mckay@nasa.gov
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SN 1531-1074
J9 ASTROBIOLOGY
JI Astrobiology
PD OCT
PY 2008
VL 8
IS 5
BP 909
EP 919
DI 10.1089/ast.2008.0265
PG 11
WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary
SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics;
Geology
GA 391RJ
UT WOS:000262250100004
PM 18950287
ER
PT J
AU Stoker, CR
Cannon, HN
Dunagan, SE
Lemke, LG
Glass, BJ
Miller, D
Gomez-Elvira, J
Davis, K
Zavaleta, J
Winterholler, A
Roman, M
Rodriguez-Manfredi, JA
Bonaccorsi, R
Bell, MS
Brown, A
Battler, M
Chen, B
Cooper, G
Davidson, M
Fernandez-Remolar, D
Gonzales-Pastor, E
Heldmann, JL
Martinez-Frias, J
Parro, V
Prieto-Ballesteros, O
Sutter, B
Schuerger, AC
Schutt, J
Rull, F
AF Stoker, Carol R.
Cannon, Howard N.
Dunagan, Stephen E.
Lemke, Lawrence G.
Glass, Brian J.
Miller, David
Gomez-Elvira, Javier
Davis, Kiel
Zavaleta, Jhony
Winterholler, Alois
Roman, Matt
Antonio Rodriguez-Manfredi, Jose
Bonaccorsi, Rosalba
Bell, Mary Sue
Brown, Adrian
Battler, Melissa
Chen, Bin
Cooper, George
Davidson, Mark
Fernandez-Remolar, David
Gonzales-Pastor, Eduardo
Heldmann, Jennifer L.
Martinez-Frias, Jesus
Parro, Victor
Prieto-Ballesteros, Olga
Sutter, Brad
Schuerger, Andrew C.
Schutt, John
Rull, Fernando
TI The 2005 MARTE Robotic Drilling Experiment in Rio Tinto, Spain:
Objectives, Approach, and Results of a Simulated Mission to Search for
Life in the Martian Subsurface
SO ASTROBIOLOGY
LA English
DT Article
DE Mars; Drilling; Mission simulation; Field test; Life detection;
Subsurface biology
ID EXTREME ACIDIC ENVIRONMENT; MASSIVE SULFIDE DEPOSITS; MERIDIANI-PLANUM;
WATER; MODEL; RIVER; ECOSYSTEMS; EVOLUTION; HEMATITE; HYDROGEN
AB The Mars Astrobiology Research and Technology Experiment (MARTE) simulated a robotic drilling mission to search for subsurface life on Mars. The drill site was on Pena de Hierro near the headwaters of the Rio Tinto river (southwest Spain), on a deposit that includes massive sulfides and their gossanized remains that resemble some iron and sulfur minerals found on Mars. The mission used a fluidless, 10-axis, autonomous coring drill mounted on a simulated lander. Cores were faced; then instruments collected color wide-angle context images, color microscopic images, visible-near infrared point spectra, and (lower resolution) visible-near infrared hyperspectral images. Cores were then stored for further processing or ejected. A borehole inspection system collected panoramic imaging and Raman spectra of borehole walls. Life detection was performed on full cores with an adenosine triphosphate luciferin-luciferase bioluminescence assay and on crushed core sections with SOLID2, an antibody array-based instrument. Two remotely located science teams analyzed the remote sensing data and chose subsample locations. In 30 days of operation, the drill penetrated to 6 m and collected 21 cores. Biosignatures were detected in 12 of 15 samples analyzed by SOLID2. Science teams correctly interpreted the nature of the deposits drilled as compared to the ground truth. This experiment shows that drilling to search for subsurface life on Mars is technically feasible and scientifically rewarding.
C1 [Stoker, Carol R.; Cannon, Howard N.; Dunagan, Stephen E.; Lemke, Lawrence G.; Glass, Brian J.; Zavaleta, Jhony; Bonaccorsi, Rosalba; Heldmann, Jennifer L.] NASA, Ames Res Ctr, Moffett Field, CA 94305 USA.
[Miller, David; Winterholler, Alois; Roman, Matt] Univ Oklahoma, Sch Aerosp & Mech Engn, Norman, OK 73019 USA.
[Gomez-Elvira, Javier; Antonio Rodriguez-Manfredi, Jose; Fernandez-Remolar, David; Gonzales-Pastor, Eduardo; Martinez-Frias, Jesus; Parro, Victor; Prieto-Ballesteros, Olga; Rull, Fernando] CSIC INTA, Ctr Astrobiol, Madrid, Spain.
[Davis, Kiel] Honeybee Robot Spacecraft Mech Corp, New York, NY USA.
[Bell, Mary Sue; Sutter, Brad] NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA.
[Brown, Adrian; Chen, Bin] SETI Inst, Mountain View, CA USA.
[Battler, Melissa] Univ New Brunswick, Fredericton, NB E3B 5A3, Canada.
[Cooper, George] Univ Calif Berkeley, Berkeley, CA 94720 USA.
[Davidson, Mark] Princeton Univ, Dept Geosci, Princeton, NJ 08544 USA.
[Schuerger, Andrew C.] Univ Florida, Dept Plant Pathol, Gainesville, FL 32611 USA.
[Schutt, John] Mars Inst, Moffett Field, CA USA.
RP Stoker, CR (reprint author), NASA, Ames Res Ctr, Mail Stop 245-3, Moffett Field, CA 94305 USA.
EM cstoker@mail.arc.nasa.gov
RI Gomez-Elvira, Javier/K-5829-2014; Rodriguez-Manfredi, Jose/L-8001-2014;
Battler, Melissa/N-2591-2014; Gonzalez-Pastor, Jose/I-2118-2015
OI Gomez-Elvira, Javier/0000-0002-9068-9846; Rodriguez-Manfredi,
Jose/0000-0003-0461-9815; Gonzalez-Pastor, Jose/0000-0002-7615-7042
FU NASA Astrobiology Science and Technology [NRA 02-OSS-01]; Centro de
Astrobiologia
FX MARTE was funded by the NASA Astrobiology Science and Technology for
Exploring Planets (ASTEP) program through NRA 02-OSS-01. Spanish
participation in MARTE was funded by the Centro de Astrobiologia. We are
especially grateful to NASA ASTEP program manager Dr. Michael Meyer and
CAB Director Dr. Juan Perez-Mercader for strongly supporting the
project. We gratefully acknowledge the hard work and camaraderie from
the many individuals who participated in the MARTE project, for their
contributions to the development of the MARTE drilling system and their
support during the extensive field work. Special thanks to Khoa Nguyen,
Steven Beard, and Bruce Felt (and associates) for supporting the MARTE
drill integration and to field team members of the robotics experiment:
Scott Christa, Sara Huffman, Jen Jasper, Mark Branson, Thom Stone,
Richard Alena, John Ossenfort, Steve Schultz, Kennda Lynch, Charlie
Galindo, Michelle Goldschmid, Eric James, Erik Mumm, Tom Kennedy, Gale
Paulsen, Jason Herman, Michael Rutberg, Josefina Torres Redondo, Eduardo
Sebastian Martinez, Sara Navarro Lopez, and Mercedes Moreno Paz. The
Museo Minero de Riotinto provided critical field facilities and
logistical support to the MARTE project. The Vazquez Diaz Hotel in
Nerva, Spain provided additional logistical support, great meals,
fabulous service, and a home away from home for the field team. Finally,
the MARTE project would not have been possible without numerous
contributions from Ricardo Amils and Todd Stevens. Gracias amigos.
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SN 1531-1074
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JI Astrobiology
PD OCT
PY 2008
VL 8
IS 5
BP 921
EP 945
DI 10.1089/ast.2007.0217
PG 25
WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary
SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics;
Geology
GA 391RJ
UT WOS:000262250100005
PM 19032053
ER
PT J
AU Bonaccorsi, R
Stoker, CR
AF Bonaccorsi, Rosalba
Stoker, Carol R.
TI Science Results from a Mars Drilling Simulation (Rio Tinto, Spain) and
Ground Truth for Remote Science Observations
SO ASTROBIOLOGY
LA English
DT Review
DE Mars; Rio Tinto; Robotic drilling; Ground truth; Lithostratigraphy;
Phyllosilicates; Astrobiology; Organics; Life detection
ID EXTREME ACIDIC ENVIRONMENT; MASSIVE SULFIDE DEPOSITS; TOTAL
ORGANIC-CARBON; IBERIAN PYRITE BELT; MERIDIANI-PLANUM; MARTIAN SOIL; ATP
BIOLUMINESCENCE; MICROBIAL ECOLOGY; HEMATITE; MATTER
AB Science results from a field-simulated lander payload and post-mission laboratory investigations provided "ground truth" to interpret remote science observations made as part of the 2005 Mars Astrobiology Research and Technology Experiment (MARTE) drilling mission simulation. The experiment was successful in detecting evidence for life, habitability, and preservation potential of organics in a relevant astrobiological analogue of Mars.
Science results. Borehole 7 was drilled near the Rio Tinto headwaters at Pena de Hierro (Spain) in the upper oxidized remnant of an acid rock drainage system. Analysis of 29 cores ( 215 cm of core was recovered from 606 cm penetrated depth) revealed a matrix of goethite-(42-94%) and hematite-rich (47-87%) rocks with pockets of phyllosilicates (47-74%) and fine- to coarse-grained loose material. Post-mission X-ray diffraction (XRD) analysis confirmed the range of hematite: goethite mixtures that were visually recognizable (similar to 1:1, similar to 1:2, and similar to 1:3 mixtures displayed a yellowish- red color whereas 3:1 mixtures displayed a dark reddish-brown color). Organic carbon was poorly preserved in hematite/goethite-rich materials (C-org <0.05 wt %) beneath the biologically active organic-rich soil horizon (Corg similar to 3-11 wt %) in contrast to the phyllosilicate-rich zones (C-org similar to 0.23 wt %).
Ground truth vs. remote science analysis. Laboratory-based analytical results were compared to the analyses obtained by a Remote Science Team (RST) using a blind protocol. Ferric iron phases, lithostratigraphy, and inferred geologic history were correctly identified by the RST with the exception of phyllosilicate-rich materials that were misinterpreted as weathered igneous rock. Adenosine 5'-triphosphate (ATP) luminometry, a tool available to the RST, revealed ATP amounts above background noise, i.e., 278-876 Relative Luminosity Units (RLUs) in only 6 cores, whereas organic carbon was detected in all cores. Our manned vs. remote observations based on automated acquisitions during the project provide insights for the preparation of future astrobiology-driven Mars missions.
C1 [Bonaccorsi, Rosalba; Stoker, Carol R.] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
RP Bonaccorsi, R (reprint author), NASA, Ames Res Ctr, Mail Stop 245-3, Moffett Field, CA 94035 USA.
EM rbonaccorsi@mail.arc.nasa.gov
FU NASA ASTEP [NRA 02-OSS-01]
FX This work was funded by the NASA ASTEP program through NRA 02-OSS-01 to
C. S. and by the NASA Postdoctoral Program (former NRC) administered by
Oak Ridge Associated Universities to R. B. Brad Sutter provided the XRD
analysis and a helpful editorial review of the manuscript. The comments
of L. Roach and two other anonymous reviewers consistently improved the
quality of this manuscript. We are particularly grateful to the entire
MARTE team involved in the 2005 experiment and the Remote Science Team.
Special thanks go to J. Zavaleta, H. Cannon, S. Dunagan, L. Lemke, B.
Glass, K. Lynch, M. S. Bell, and C. Galindo for having provided
outstanding help and logistic support at the drill site. Dyke Andreasen
(UCSC) provided valuable technical support with EA-IRMS analyses. We are
also grateful to V. Parro, R. Amils, T. Stevens, C. P. McKay, and G.
Marzo for their valuable suggestions. The personnel of the Museo Minero
de Riotinto and Hotel Vazquez Diaz kindly provided field facilities and
logistical support.
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EI 1557-8070
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JI Astrobiology
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BP 967
EP 985
DI 10.1089/ast.2007.0152
PG 19
WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary
SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics;
Geology
GA 391RJ
UT WOS:000262250100007
PM 19105754
ER
PT J
AU Parro, V
Fernandez-Calvo, PF
Manfredi, JAR
Moreno-Paz, M
Rivas, LA
Garcia-Villadangos, M
Bonaccorsi, R
Gonzalez-Pastor, JE
Prieto-Ballesteros, O
Schuerger, AC
Davidson, M
Gomez-Elvira, J
Stoker, CR
AF Parro, Victor
Fernandez-Calvo, Patricia
Rodriguez Manfredi, Jose A.
Moreno-Paz, Mercedes
Rivas, Luis A.
Garcia-Villadangos, Miriam
Bonaccorsi, Rosalba
Eduardo Gonzalez-Pastor, Jose
Prieto-Ballesteros, Olga
Schuerger, Andrew C.
Davidson, Mark
Gomez-Elvira, Javier
Stoker, Carol R.
TI SOLID2: An Antibody Array-Based Life-Detector Instrument in a Mars
Drilling Simulation Experiment (MARTE)
SO ASTROBIOLOGY
LA English
DT Article
DE SOLID instrument; MARTE project; Antibody microarray; Rio Tinto
subsurface as Mars analogue
ID ASTROBIOLOGY; MICROARRAYS; INHIBITION; BIOMARKERS; EVOLUTION; PROTEINS;
HEMATITE; COMPLEX; SURFACE; SEARCH
AB A field prototype of an antibody array-based life-detector instrument, Signs of Life Detector (SOLID2), has been tested in a Mars drilling mission simulation called MARTE (Mars Astrobiology Research and Technology Experiment). As one of the analytical instruments on the MARTE robotic drilling rig, SOLID2 performed automatic sample processing and analysis of ground core samples (0.5 g) with protein microarrays that contained 157 different antibodies. Core samples from different depths (down to 5.5 m) were analyzed, and positive reactions were obtained in antibodies raised against the Gram-negative bacterium Leptospirillum ferrooxidans, a species of the genus Acidithiobacillus (both common microorganisms in the Rio Tinto area), and extracts from biofilms and other natural samples from the Rio Tinto area. These positive reactions were absent when the samples were previously subjected to a high-temperature treatment, which indicates the biological origin and structural dependency of the antibody-antigen reactions. We conclude that an antibody array-based life-detector instrument like SOLID2 can detect complex biological material, and it should be considered as a potential analytical instrument for future planetary missions that search for life.
C1 [Parro, Victor; Fernandez-Calvo, Patricia; Rodriguez Manfredi, Jose A.; Moreno-Paz, Mercedes; Rivas, Luis A.; Garcia-Villadangos, Miriam; Eduardo Gonzalez-Pastor, Jose; Prieto-Ballesteros, Olga; Gomez-Elvira, Javier] INTA CSIC, Ctr Astrobiol, Madrid 28850, Spain.
[Schuerger, Andrew C.] Univ Florida, Dept Plant Pathol, Space Life Sci Lab, Kennedy Space Ctr, Gainesville, FL 32611 USA.
[Bonaccorsi, Rosalba; Stoker, Carol R.] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
[Davidson, Mark] Princeton Univ, Dept Geosci, Princeton, NJ 08544 USA.
RP Parro, V (reprint author), INTA CSIC, Ctr Astrobiol, Carretera Ajalvir Km 4, Madrid 28850, Spain.
EM parrogv@inta.es
RI Gomez-Elvira, Javier/K-5829-2014; Rodriguez-Manfredi, Jose/L-8001-2014;
Gonzalez-Pastor, Jose/I-2118-2015
OI Gomez-Elvira, Javier/0000-0002-9068-9846; Rodriguez-Manfredi,
Jose/0000-0003-0461-9815; Gonzalez-Pastor, Jose/0000-0002-7615-7042
FU Spanish Ministerio de Educacion y Ciencia [ESP2004-05008]; Centro de
Astrobiologia (CAB); Instituto Nacional de Tecnica Aeroespacial (INTA);
National Aeronautics and Space Administration (NASA); Astrobiology
Science and Technology for Exploring Planets (ASTEP) [NRA 02-OSS-01]
FX We thank Julio J. Romeral, Josefina Torres, and Sara Navarro for
excellent technical assistance in the field, the MARTE team, and
Professor Juan Perez-Mercader for his unconditional support. The work
was funded by the Spanish Ministerio de Educacion y Ciencia
(ESP2004-05008), the Centro de Astrobiologia (CAB), the Instituto
Nacional de Tecnica Aeroespacial (INTA), and by the National Aeronautics
and Space Administration (NASA) Astrobiology Science and Technology for
Exploring Planets (ASTEP) program under NRA 02-OSS-01.
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SN 1531-1074
EI 1557-8070
J9 ASTROBIOLOGY
JI Astrobiology
PD OCT
PY 2008
VL 8
IS 5
BP 987
EP 999
DI 10.1089/ast.2007.0126
PG 13
WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary
SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics;
Geology
GA 391RJ
UT WOS:000262250100008
PM 19105755
ER
PT J
AU Brown, AJ
Sutter, B
Dunagan, S
AF Brown, Adrian J.
Sutter, Brad
Dunagan, Stephen
TI The MARTE VNIR Imaging Spectrometer Experiment: Design and Analysis
SO ASTROBIOLOGY
LA English
DT Article
DE Mars; Analogue; Rio Tinto; Reflectance spectroscopy; Infrared
spectroscopy
ID NORTH-POLE DOME; WESTERN-AUSTRALIA; PILBARA CRATON; REFLECTANCE;
SPECTROSCOPY; MINERALS
AB We report on the design, operation, and data analysis methods employed on the VNIR imaging spectrometer instrument that was part of the Mars Astrobiology Research and Technology Experiment (MARTE). The imaging spectrometer is a hyperspectral scanning pushbroom device sensitive to VNIR wavelengths from 400-1000 nm. During the MARTE project, the spectrometer was deployed to the Rio Tinto region of Spain. We analyzed subsets of three cores from Rio Tinto using a new band modeling technique. We found most of the MARTE drill cores to contain predominantly goethite, though spatially coherent areas of hematite were identified in Core 23. We also distinguished non Fe-bearing minerals that were subsequently analyzed by X-ray diffraction (XRD) and found to be primarily muscovite. We present drill core maps that include spectra of goethite, hematite, and non Fe-bearing minerals.
C1 [Brown, Adrian J.] SETI Inst, Mountain View, CA 94043 USA.
[Brown, Adrian J.; Sutter, Brad; Dunagan, Stephen] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
RP Brown, AJ (reprint author), SETI Inst, 515 N Whisman Rd, Mountain View, CA 94043 USA.
EM abrown@seti.org
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SN 1531-1074
EI 1557-8070
J9 ASTROBIOLOGY
JI Astrobiology
PD OCT
PY 2008
VL 8
IS 5
BP 1001
EP 1011
DI 10.1089/ast.2007.0142
PG 11
WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary
SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics;
Geology
GA 391RJ
UT WOS:000262250100009
PM 19105756
ER
PT J
AU Prieto-Ballesteros, O
Martinez-Frias, J
Schutt, J
Sutter, B
Heldmann, JL
Bell, MS
Battler, M
Cannon, H
Gomez-Elvira, J
Stoker, CR
AF Prieto-Ballesteros, Olga
Martinez-Frias, Jesus
Schutt, John
Sutter, Brad
Heldmann, Jennifer L.
Bell, Mary Sue
Battler, Melissa
Cannon, Howard
Gomez-Elvira, Javier
Stoker, Carol R.
TI The Subsurface Geology of Rio Tinto: Material Examined During a
Simulated Mars Drilling Mission for the Mars Astrobiology Research and
Technology Experiment (MARTE)
SO ASTROBIOLOGY
LA English
DT Article
DE Mars; Rio Tinto; Iron oxides; Drilling core; Remote mineralogical
analysis
ID IBERIAN PYRITE BELT; MERIDIANI-PLANUM; ENVIRONMENT; MINERALOGY;
HEMATITE; BASIN
AB The 2005 Mars Astrobiology Research and Technology Experiment (MARTE) project conducted a simulated 1-month Mars drilling mission in the Rio Tinto district, Spain. Dry robotic drilling, core sampling, and biological and geological analytical technologies were collectively tested for the first time for potential use on Mars. Drilling and subsurface sampling and analytical technologies are being explored for Mars because the subsurface is the most likely place to find life on Mars. The objectives of this work are to describe drilling, sampling, and analytical procedures; present the geological analysis of core and borehole material; and examine lessons learned from the drilling simulation. Drilling occurred at an undisclosed location, causing the science team to rely only on mission data for geological and biological interpretations. Core and borehole imaging was used for micromorphological analysis of rock, targeting rock for biological analysis, and making decisions regarding the next day's drilling operations. Drilling reached 606 cm depth into poorly consolidated gossan that allowed only 35% of core recovery and contributed to borehole wall failure during drilling. Core material containing any indication of biology was sampled and analyzed in more detail for its confirmation. Despite the poorly consolidated nature of the subsurface gossan, dry drilling was able to retrieve useful core material for geological and biological analysis. Lessons learned from this drilling simulation can guide the development of dry drilling and subsurface geological and biological analytical technologies for future Mars drilling missions.
C1 [Prieto-Ballesteros, Olga; Martinez-Frias, Jesus; Gomez-Elvira, Javier] CSIC, INTA, Ctr Astrobiol, Madrid 28850, Spain.
[Schutt, John] NASA, Ames Res Ctr, Mars Inst, Moffett Field, CA 94035 USA.
[Sutter, Brad] SETI Inst, Mountain View, CA USA.
[Heldmann, Jennifer L.; Cannon, Howard; Stoker, Carol R.] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
[Bell, Mary Sue] NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA.
[Battler, Melissa] Univ New Brunswick, Fredericton, NB, Canada.
RP Prieto-Ballesteros, O (reprint author), CSIC, INTA, Ctr Astrobiol, Carretera Ajalvir Km 4, Madrid 28850, Spain.
EM prietobo@inta.es
RI Gomez-Elvira, Javier/K-5829-2014; Battler, Melissa/N-2591-2014
OI Gomez-Elvira, Javier/0000-0002-9068-9846;
NR 22
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U1 0
U2 3
PU MARY ANN LIEBERT INC
PI NEW ROCHELLE
PA 140 HUGUENOT STREET, 3RD FL, NEW ROCHELLE, NY 10801 USA
SN 1531-1074
J9 ASTROBIOLOGY
JI Astrobiology
PD OCT
PY 2008
VL 8
IS 5
BP 1013
EP 1021
DI 10.1089/ast.2006.0107
PG 9
WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary
SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics;
Geology
GA 391RJ
UT WOS:000262250100010
PM 19105757
ER
PT J
AU Fernandez-Remolar, DC
Prieto-Ballesteros, O
Rodriguez, N
Gomez, F
Amils, R
Gomez-Elvira, J
Stoker, CR
AF Fernandez-Remolar, David C.
Prieto-Ballesteros, Olga
Rodriguez, Nuria
Gomez, Felipe
Amils, Ricardo
Gomez-Elvira, Javier
Stoker, Carol R.
TI Underground Habitats in the Rio Tinto Basin: A Model for Subsurface Life
Habitats on Mars
SO ASTROBIOLOGY
LA English
DT Article
DE Rio Tinto; Subsurface habitats; Mars analogue
ID IBERIAN PYRITE BELT; TERRESTRIAL ANALOGS; MERIDIANI-PLANUM; GEOLOGIC
RECORD; EVOLUTION; IRON; MINERALOGY; ENVIRONMENTS; CALIFORNIA; DEPOSITS
AB A search for evidence of cryptic life in the subsurface region of a fractured Paleozoic volcanosedimentary deposit near the source waters of the Rio Tinto River (Iberian pyrite belt, southwest Spain) was carried out by Mars Astrobiology Research and Technology Experiment (MARTE) project investigators in 2003 and 2004. This conventional deep-drilling experiment is referred to as the MARTE ground truth drilling project. Boreholes were drilled at three sites, and samples from extracted cores were analyzed with light microscopy, scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy. Core leachates were analyzed with ion chromatography, and borehole fluids were analyzed with ion and gas chromatography. Key variables of the groundwater system (e. g., pO(2), pH, and salinity) exhibit huge ranges probably due to surficial oxygenation of overall reducing waters, physical mixing of waters, and biologically mediated water-rock interactions. Mineral distribution is mainly driven by the pH of subsurface solutions, which range from highly acidic to neutral. Borehole fluids contain dissolved gases such as CO2, CH4, and H-2. SEM-EDS analyses of core samples revealed evidence of microbes attacking pyrite. The Rio Tinto alteration mechanisms may be similar to subsurface weathering of the martian crust and provide insights into the possible (bio)geochemical cycles that may have accompanied underground habitats in extensive early Mars volcanic regions and associated sulfide ores.
C1 [Fernandez-Remolar, David C.; Prieto-Ballesteros, Olga; Rodriguez, Nuria; Gomez, Felipe; Amils, Ricardo; Gomez-Elvira, Javier] INTA CSIC, Ctr Astrobiol, Torrejon De Ardoz 28850, Spain.
[Amils, Ricardo] Univ Autonoma Madrid, Ctr Biol Mol, E-28049 Madrid, Spain.
[Stoker, Carol R.] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
RP Fernandez-Remolar, DC (reprint author), INTA CSIC, Ctr Astrobiol, Ctra Ajalvir Km 4, Torrejon De Ardoz 28850, Spain.
EM fernandezrd@inta.es
RI Gomez-Elvira, Javier/K-5829-2014; Gomez, Felipe/L-7315-2014
OI Gomez-Elvira, Javier/0000-0002-9068-9846; Gomez,
Felipe/0000-0001-9977-7060
FU ASTEP " Mars Astrobiology Research and Technology Ex-periment (MARTE)
[NRA-02-OSS-01]; Mars analog drilling project to search for subsurface
life at Rio Tinto [ESP 2003 03692]; Sonda para la exploracion remota del
subsuelo de Marte" [ESP 200609487]; Estudio de los procesos de oxidacion
superficiales y subterraneos en las Fuentes acidas del Rio Tinto:
construcion de modelos geoquimicos para la interpretacion de ambientes
primitivos en Marte
FX This study was supported by the projects NRA-02-OSS-01 ASTEP " Mars
Astrobiology Research and Technology Ex-periment (MARTE)" a Mars analog
drilling project to search for subsurface life at Rio Tinto, ESP 2003
03692 "Sonda para la exploracion remota del subsuelo de Marte" and ESP
200609487 " Estudio de los procesos de oxidacion superficiales y
subterraneos en las Fuentes acidas del Rio Tinto: construcion de modelos
geoquimicos para la interpretacion de ambientes primitivos en Marte."
Authors appreciate the strong support provided by the MARTE Science and
Technology Teams, the CAB scientific and technical personnel, and the
CAB director Professor Juan Perez-Mercader. We also appreciate the
analytical support provided by the Chemin team lead at Rio Tinto,
Philippe Sarrazin, which was most useful in the field. Finally, we
sincerely appreciate the suggestions given by two anonymous reviewers
and the excellent editorial support provided by Sherry Cady, which
greatly improved the manuscript.
NR 57
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PU MARY ANN LIEBERT, INC
PI NEW ROCHELLE
PA 140 HUGUENOT STREET, 3RD FL, NEW ROCHELLE, NY 10801 USA
SN 1531-1074
EI 1557-8070
J9 ASTROBIOLOGY
JI Astrobiology
PD OCT
PY 2008
VL 8
IS 5
BP 1023
EP 1047
DI 10.1089/ast.2006.0104
PG 25
WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary
SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics;
Geology
GA 391RJ
UT WOS:000262250100011
PM 19105758
ER
PT J
AU Sutter, B
Brown, AJ
Stoker, CR
AF Sutter, Brad
Brown, Adrian J.
Stoker, Carol R.
TI Visible-Near Infrared Point Spectrometry of Drill Core Samples from Rio
Tinto, Spain: Results from the 2005 Mars Astrobiology Research and
Technology Experiment (MARTE) Drilling Exercise
SO ASTROBIOLOGY
LA English
DT Article
DE Rio Tinto; Mars; Drilling; Infrared; Iron oxides; Jarosite;
Phyllosilicates
ID OMEGA/MARS EXPRESS; MERIDIANI-PLANUM; MINERALOGY; HEMATITE; REGION;
REFLECTANCE; JAROSITE; GOETHITE; DEPOSITS; OXIDES
AB Sampling of subsurface rock may be required to detect evidence of past biological activity on Mars. The Mars Astrobiology Research and Technology Experiment (MARTE) utilized the Rio Tinto region, Spain, as a Mars analog site to test dry drilling technologies specific to Mars that retrieve subsurface rock for biological analysis. This work examines the usefulness of visible-near infrared (VNIR) (450-1000 nm) point spectrometry to characterize ferric iron minerals in core material retrieved during a simulated Mars drilling mission. VNIR spectrometry can indicate the presence of aqueously precipitated ferric iron minerals and, thus, determine whether biological analysis of retrieved rock is warranted. Core spectra obtained during the mission with T1 (893-897 nm) and T2 (644-652 nm) features indicate goethite-dominated samples, while relatively lower wavelength T1 (832-880 nm) features indicate hematite. Hematite/goethite molar ratios varied from 0 to 1.4, and within the 880-898 nm range, T1 features were used to estimate hematite/goethite molar ratios. Post-mission X-ray analysis detected phyllosilicates, which indicates that examining beyond the VNIR (e. g., shortwave infrared, 1000-2500 nm) will enhance the detection of other minerals formed by aqueous processes. Despite the limited spectral range of VNIR point spectrometry utilized in the MARTE Mars drilling simulation project, ferric iron minerals could be identified in retrieved core material, and their distribution served to direct core subsampling for biological analysis.
C1 [Sutter, Brad; Brown, Adrian J.; Stoker, Carol R.] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
[Brown, Adrian J.] SETI Inst, Mountain View, CA USA.
RP Sutter, B (reprint author), ESCG, Jacobs Technol, Mail Code JE-23,POB 58447, Houston, TX 77258 USA.
EM Brad.Sutter-2@nasa.gov
FU NASA's Astrobiology Science and Technology
FX This work was funded by a grant from NASA's Astrobiology Science and
Technology for Exploring Planets (ASTEP) program. The authors would like
to thank Janice Bishop for the generous use of her ASD spectrometer. The
authors gratefully acknowledge T. Roush, the associate editor for
Astrobiology, reviewer L. H. Roach, and one anonymous reviewer for their
thoughtful reviews.
NR 35
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U1 0
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PU MARY ANN LIEBERT, INC
PI NEW ROCHELLE
PA 140 HUGUENOT STREET, 3RD FL, NEW ROCHELLE, NY 10801 USA
SN 1531-1074
EI 1557-8070
J9 ASTROBIOLOGY
JI Astrobiology
PD OCT
PY 2008
VL 8
IS 5
BP 1049
EP 1060
DI 10.1089/ast.2007.0146
PG 12
WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary
SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics;
Geology
GA 391RJ
UT WOS:000262250100012
PM 19105759
ER
PT J
AU Person, MJ
Elliot, JL
Gulbis, AAS
Zuluaga, CA
Babcock, BA
Mckay, AJ
Pasachoff, JM
Souza, SP
Hubbard, WB
Kulesa, CA
McCarthy, DW
Benecchi, SD
Levine, SE
Bosh, AS
Ryan, EV
Ryan, WH
Meyer, A
Wolf, J
Hill, J
AF Person, M. J.
Elliot, J. L.
Gulbis, A. A. S.
Zuluaga, C. A.
Babcock, B. A.
Mckay, A. J.
Pasachoff, J. M.
Souza, S. P.
Hubbard, W. B.
Kulesa, C. A.
McCarthy, D. W.
Benecchi, S. D.
Levine, S. E.
Bosh, A. S.
Ryan, E. V.
Ryan, W. H.
Meyer, A.
Wolf, J.
Hill, J.
TI Waves in Pluto's upper atmosphere
SO ASTRONOMICAL JOURNAL
LA English
DT Article
DE occultations; planets and satellites : individual (Pluto); waves
ID STELLAR OCCULTATION DATA; JOVIAN UPPER-ATMOSPHERE;
PLANETARY-ATMOSPHERES; GRAVITY-WAVES; CIRCULATION; INVERSION; MODELS;
MARS
AB Observations of the 2007 March 18 occultation of the star P445.3 (2UCAC 25823784; R = 15.3) by Pluto were obtained at high time resolution at five sites across the western United States and reduced to produce light curves for each station using standard aperture photometry. Global models of Pluto's upper atmosphere are fitted simultaneously to all resulting light curves. The results of these model fits indicate that the structure of Pluto's upper atmosphere is essentially unchanged since the previous occultation observed in 2006, leading to a well-constrained measurement of the atmospheric half-light radius at 1291 +/- 5 km. These results also confirm that the significant increase in atmospheric pressure detected between 1988 and 2002 has ceased. Inversion of the Multiple Mirror Telescope Observatory light curves with unprecedented signal-to-noise ratios reveals significant oscillations in the number density, pressure, and temperature profiles of Pluto's atmosphere. Detailed analysis of this highest resolution light curve indicates that these variations in Pluto's upper atmospheric structure exhibit a previously unseen oscillatory structure with strong correlations of features among locations separated by almost 1200 km in Pluto's atmosphere. Thus, we conclude that these variations are caused by some form of large-scale atmospheric waves. Interpreting these oscillations as Rossby (planetary) waves allows us to establish an upper limit of less than 3 m s(-1) for horizontal wind speeds in the sampled region (radius 1340-1460 km) of Pluto's upper atmosphere.
C1 [Person, M. J.; Elliot, J. L.; Gulbis, A. A. S.; Zuluaga, C. A.] MIT, Dept Earth Atmospher & Planetary Sci, Cambridge, MA 02139 USA.
[Elliot, J. L.] MIT, Dept Phys, Cambridge, MA 02139 USA.
[Elliot, J. L.] Lowell Observ, Flagstaff, AZ 86001 USA.
[Gulbis, A. A. S.] S African Astron Observ, ZA-7935 Cape Town, South Africa.
[Babcock, B. A.] Williams Coll, Dept Phys, Williamstown, MA 01267 USA.
[Mckay, A. J.; Pasachoff, J. M.; Souza, S. P.] Williams Coll, Dept Astron, Williamstown, MA 01267 USA.
[Hubbard, W. B.] Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA.
[Kulesa, C. A.; McCarthy, D. W.] Univ Arizona, Steward Observ, Tucson, AZ 85721 USA.
[Benecchi, S. D.] STScI, Baltimore, MD 21218 USA.
[Levine, S. E.] USNO Flagstaff Stn, Flagstaff, AZ 86002 USA.
[Bosh, A. S.] Boston Univ, Dept Astron, Boston, MA 02215 USA.
[Ryan, E. V.; Ryan, W. H.] New Mexico Inst Min & Technol, Magdalena Ridge Observ, Socorro, NM 87801 USA.
[Meyer, A.] NASA, Ames Res Ctr, SOFIA, Univ Space Res Assoc, Moffett Field, CA 94035 USA.
[Wolf, J.] NASA, Ames Res Ctr, SOFIA, Deutsch SOFIA Inst, Moffett Field, CA 94035 USA.
[Hill, J.] Univ Arizona, Large Binocular Telescope Observ, Tucson, AZ 85721 USA.
RP Person, MJ (reprint author), MIT, Dept Earth Atmospher & Planetary Sci, 77 Massachusetts Ave, Cambridge, MA 02139 USA.
FU NASA Planetary Astronomy [NNG04GE48G, NNG04GF25G, NNH04ZSS001N,
NNG05GG75G, NNX08AO50G]; Astronomy Camp
FX We thank the engineering staffs of MMTO, LBTO, USNO, and MRO for their
assistance. We especially thank Shawn Callahan (MMTO) for his extensive
efforts allowing us to co-mount PISCES and POETS at the MMTO. We also
thank Alan Plumb (MIT) for his theoretical insights and discussions.
This work was partially funded by NASA Planetary Astronomy grants
NNG04GE48G, NNG04GF25G, NNH04ZSS001N, NNG05GG75G, and NNX08AO50G to MIT
and Williams College. Partial funding for MMTO observations was also
provided by Astronomy Camp. Some of the observations reported here were
obtained at the MMT Observatory, a joint facility of the University of
Arizona and the Smithsonian Institution.
NR 30
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U1 0
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PU IOP PUBLISHING LTD
PI BRISTOL
PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND
SN 0004-6256
J9 ASTRON J
JI Astron. J.
PD OCT
PY 2008
VL 136
IS 4
BP 1510
EP 1518
DI 10.1088/0004-6256/136/4/1510
PG 9
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 348HY
UT WOS:000259202800011
ER
PT J
AU Protopapa, S
Boehnhardt, H
Herbst, TM
Cruikshank, DP
Grundy, WM
Merlin, F
Olkin, CB
AF Protopapa, S.
Boehnhardt, H.
Herbst, T. M.
Cruikshank, D. P.
Grundy, W. M.
Merlin, F.
Olkin, C. B.
TI Surface characterization of Pluto and Charon by L and M band spectra
SO ASTRONOMY & ASTROPHYSICS
LA English
DT Article
DE Kuiper Belt; techniques: spectroscopic; methods: numerical; scattering
ID NEAR-INFRARED SPECTROSCOPY; KUIPER-BELT OBJECTS; 136472 2005 FY9;
PHYSICAL STATE; TRITON; ICES; METHANE; N-2; H2O; CO
AB Context. One of the main scientific objectives of NASA's New Horizons mission is to map the icy surface compositions of Pluto and its moon Charon. The encounter will be in 2015. Meanwhile remote observations from earth and space are the most suitable means to enhance further our knowledge of the Pluto/Charon system.
Aims. We intend to assist the New Horizons mission by improving our knowledge of Pluto's and Charon's surface compositions. Specifically, we extend the wavelength coverage of the surface spectroscopy beyond the K band, with the goal to detect further surface ice absorption bands predicted from the models that are based on the available JHK spectra, and to search for signatures of yet unknown ices. In particular we aim to resolve the binary system Pluto/Charon and to obtain, for the first time, spectra up to 5 mu m of the two objects resolved.
Methods. Spectroscopic measurements of Pluto/Charon taken with the adaptive optics instrument NACO at the ESO VLT in the interval 3-7 August 2005 were obtained. The nature and properties of the compounds present on the surface of Pluto and Charon are investigated by applying a Hapke radiative transfer model to the measured spectra.
Results. We present Pluto's reflectance spectrum in the wavelength range (1-5) mu m. Apart from known and expected absorption bands of methane ice, our Pluto spectrum reveals a new absorption band centered near 4.6 mu m, not previously detected. This absorption band could be related to the presence of CO and nitriles (compounds of C and N connected with a triple bond). A geographic mixture of pure methane ice with two different grain sizes, methane and CO ice diluted in nitrogen, CH(2)CHCN and titan tholin gives the best fit to Pluto's spectrum, although not in all details. Differences compared to published Pluto spectra from 2001 taken at similar longitude could be due to a different surface coverage in latitude or to a possible resurfacing process on Pluto. Charon's spectrum is measured in the wavelength range (1-4) mu m. The surface of Charon can be modeled by pure water ice darkened by a spectrally neutral continuum absorber.
C1 [Protopapa, S.; Boehnhardt, H.] Max Planck Inst Solar Syst Res, D-37191 Katlenburg Lindau, Germany.
[Herbst, T. M.] Max Planck Inst Astron, D-69117 Heidelberg, Germany.
[Cruikshank, D. P.] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
[Grundy, W. M.] Lowell Observ, Flagstaff, AZ 86001 USA.
[Merlin, F.] Observ Paris, LESIA, F-92195 Meudon, France.
[Olkin, C. B.] SW Res Inst, Dept Space Studies, Boulder, CO USA.
RP Protopapa, S (reprint author), Max Planck Inst Solar Syst Res, Max Planck Str 2, D-37191 Katlenburg Lindau, Germany.
EM protopapa@mps.mpg.de; boehnhardt@mps.mpg.de; herbst@mpia.de;
Dale.P.Cruikshank@nasa.gov; w.grundy@lowell.edu;
frederic.merlin@obspm.fr; colkin@boulder.swri.edu
RI Protopapa, Silvia/A-3085-2010
NR 40
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PU EDP SCIENCES S A
PI LES ULIS CEDEX A
PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A,
FRANCE
SN 0004-6361
J9 ASTRON ASTROPHYS
JI Astron. Astrophys.
PD OCT
PY 2008
VL 490
IS 1
BP 365
EP 375
DI 10.1051/0004-6361:200809994
PG 11
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 359DM
UT WOS:000259966600039
ER
PT J
AU Defrere, D
Absil, O
du Foresto, VC
Danchi, WC
den Hartog, R
AF Defrere, D.
Absil, O.
du Foresto, V. Coude
Danchi, W. C.
den Hartog, R.
TI Nulling interferometry: performance comparison between space and
ground-based sites for exozodiacal disc detection
SO ASTRONOMY & ASTROPHYSICS
LA English
DT Article
DE instrumentation: high angular resolution; techniques: interferometric;
circumstellar matter
ID SUN-LIKE STARS; KELVIN-STELLAR-INTERFEROMETER; DEBRIS DISKS; PLANETS;
GENIE; REQUIREMENTS; CHARA/FLUOR; INSTRUMENT; EVOLUTION; SEARCH
AB Context. Characterising the circumstellar dust around nearby main sequence stars is a necessary step in understanding the planetary formation process and is crucial for future life-finding space missions such as ESA's Darwin or NASA's terrestrial planet finder (TPF). Besides paving the technological way to DARWIN/TPF, the space-based infrared interferometers PEGASE and FKSI (Fourier-Kelvin Stellar Interferometer) will be valuable scientific precursors.
Aims. We investigate the performance of PEGASE and FKSI for exozodiacal disc detection and compare the results with ground-based nulling interferometers.
Methods. We used the GENIEsim software (Absil et al. 2006, A&A, 448, 787) which was designed and validated to study the performance of ground-based nulling interferometers. The software has been adapted to simulate the performance of space-based nulling interferometers by disabling all atmospheric effects and by thoroughly implementing the perturbations induced by payload vibrations in the ambient space environment.
Results. Despite using relatively small telescopes (<= 0.5 m), PEGASE and FKSI are very efficient for exozodiacal disc detection. They are capable of detecting exozodiacal discs 5 and 1 time respectively, as dense as the solar zodiacal cloud, and they outperform any ground-based instrument. Unlike PEGASE, FKSI can achieve this sensitivity for most targets of the DARWIN/TPF catalogue thanks to an appropriate combination of baseline length and observing wavelength. The sensitivity of PEGASE could, however, be significantly boosted by considering a shorter interferometric baseline length.
Conclusions. Besides their main scientific goal (characterising hot giant extrasolar planets), the space-based nulling interferometers PEGASE and FKSI will be very efficient in assessing within a few minutes the level of circumstellar dust in the habitable zone around nearby main sequence stars down to the density of the solar zodiacal cloud. These space-based interferometers would be complementary to Antarctica-based instruments in terms of sky coverage and would be ideal instruments for preparing future life-finding space missions.
C1 [Defrere, D.] Univ Liege, Inst Astrophys & Geophys, B-4000 Liege, Belgium.
[Absil, O.] CNRS, LAOG, UMR 5571, F-38041 Grenoble, France.
[Absil, O.] Univ Grenoble 1, F-38041 Grenoble, France.
[du Foresto, V. Coude] CNRS, Observ Paris Meudon, LESIA, F-92195 Meudon, France.
[Danchi, W. C.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
[den Hartog, R.] ESA ESTEC, Sci Payloads & Adv Concepts Off, NL-2200 AG Noordwijk, Netherlands.
RP Defrere, D (reprint author), Univ Liege, Inst Astrophys & Geophys, 17 Allee Six Aout, B-4000 Liege, Belgium.
EM defrere@astro.ulg.ac.be
OI Absil, Olivier/0000-0002-4006-6237
FU Belgian National Science Foundation ("FRIA"); European Commission's
Sixth Framework Program as a Marie Curie Intra-European Fellow (EIF)
FX The authors are grateful to Lisa Kaltenegger (Harvard-Smithsonian Center
for Astrophysics) for providing the updated Darwin catalogue, Jean
Surdej (IAGL), Arnaud Magette (IAGL), Pierre Riaud (Paris observatory),
Tupper Hyde (NASA/GSFC), Pierre-Yves Guidotti (CNES) and Julien Morand
(EADS-Astrium) for their support and contribution. The authors also
thank Richard Barry (NASA/GSFC) for a careful reading of the manuscript.
The first author acknowledges the support of the Belgian National
Science Foundation ("FRIA"). O.A. acknowledges the financial support
from the European Commission's Sixth Framework Program as a Marie Curie
Intra-European Fellow (EIF).
NR 38
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PI LES ULIS CEDEX A
PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A,
FRANCE
SN 0004-6361
J9 ASTRON ASTROPHYS
JI Astron. Astrophys.
PD OCT
PY 2008
VL 490
IS 1
BP 435
EP 445
DI 10.1051/0004-6361:200810248
PG 11
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 359DM
UT WOS:000259966600046
ER
PT J
AU den Hartog, PR
Kuiper, L
Hermsen, W
Kaspi, VM
Dib, R
Knodlseder, J
Gavriil, FP
AF den Hartog, P. R.
Kuiper, L.
Hermsen, W.
Kaspi, V. M.
Dib, R.
Knodlseder, J.
Gavriil, F. P.
TI Detailed high-energy characteristics of AXP 4U 0142+61 - Multi-year
observations with INTEGRAL, RXTE, XMM-Newton, and ASCA
SO ASTRONOMY & ASTROPHYSICS
LA English
DT Article
DE stars : neutron; stars : pulsars : individual : 4U 0142+61; gamma rays :
observations
ID X-RAY PULSARS; SOFT GAMMA-REPEATERS; MAGNETIZED NEUTRON-STARS; IN-ORBIT
PERFORMANCE; RESONANT CYCLOTRON SCATTERING; GAS IMAGING SPECTROMETER; 4U
0142+61; COMPTON-SCATTERING; POLAR CAPS; NONTHERMAL EMISSION
AB 4U 0142+61 is one of the Anomalous X-ray Pulsars exhibiting hard X-ray emission above 10 keV discovered with INTEGRAL. In this paper we present detailed spectral and temporal characteristics both in the hard X-ray (> 10 keV) and soft X-ray (<10 keV) domains obtained using data from INTEGRAL, XMM-Newton, ASCA and RXTE. Accumulating data collected over four years with the imager IBIS-ISGRI aboard INTEGRAL, the time-averaged total spectrum shows a power-law like shape with photon index Gamma = 0.93 +/- 0.06. 4U 0142+61 is detected up to 229 keV and the flux between 20 keV and 229 keV is (15.01 +/- 0.82) x 10(-11) erg cm(-2) s(-1), which exceeds the energy flux in the 2-10 keV band by a factor of similar to 2.3. Using simultaneously collected data with the spectrometer SPI of INTEGRAL the combined total spectrum yields the first evidence for a spectral break above 100 keV. Assuming a logparabolic function for the spectral shape above 20 keV the peak energy of 4U 0142+61 is 228(-41)(+65) keV. There is no evidence for significant long-term time variability of the total emission from 4U 0142+61. Both the total flux and the spectral index are stable within the 17% level (1 sigma). Pulsed emission is measured with ISGRI up to 160 keV. The 20-160 keV profile shows a broad double-peaked pulse with a 6.2 sigma detection significance. The total pulsed spectrum can be described with a very hard power-law shape with a photon index G = 0.40 +/- 0.15 and a 20-150 keV flux of (2.68 +/- 1.34) x 10(-11) erg cm(-2) s(-1). To perform accurate phase-resolved spectroscopy over the total X-ray window, we produced pulse profiles in absolute phase for INTEGRAL-ISGRI, RXTE-PCA, XMM-Newton-PN and ASCA-GIS. The two known pulses in all soft X-ray profiles below 10 keV are located in the same phases. Three XMM-Newton observations in 2003-2004 show statistically identical profiles. However, we find a significant profile morphology change between an ASCA-GIS observation in 1999 following a possible glitch of 4U 0142+61. This change can be accounted for by differences in relative strengths and spectral shapes (0.8-10 keV) of the two pulses. The principle peak in the INTEGRAL pulse profile above 20 keV is located at the same phase as one of the pulses detected below 10 keV. The second pulse detected with INTEGRAL is slightly shifted with respect to the second peak observed in the soft X-ray band. We performed consistent phase-resolved spectroscopy over the total high-energy band and identify at least three genuinely different pulse components with different spectra. The high level of consistency between the detailed results from the four missions is indicative of a remarkably stable geometry underlying the emission scenario. Finally, we discuss the derived detailed characteristics of the high-energy emission of 4U 0142+61 in relation to three models for the non-thermal hard X-ray emission.
C1 [den Hartog, P. R.; Kuiper, L.; Hermsen, W.] SRON, Netherlands Inst Space Res, NL-3584 CA Utrecht, Netherlands.
[Hermsen, W.] Univ Amsterdam, Sterrenkundig Inst Anton Pannekoek, NL-1098 SJ Amsterdam, Netherlands.
[Kaspi, V. M.; Dib, R.] McGill Univ, Dept Phys, Montreal, PQ H3A 2T8, Canada.
[Knodlseder, J.] CNRS UPS, Ctr Etud Spatiale Rayonnements, F-31028 Toulouse 4, France.
[Gavriil, F. P.] NASA, Goddard Space Flight Ctr, Astrophys Sci Div, Xray Astrophys Lab, Greenbelt, MD 20771 USA.
RP den Hartog, PR (reprint author), SRON, Netherlands Inst Space Res, Sorbonnelaan 2, NL-3584 CA Utrecht, Netherlands.
EM Hartog@sron.nl
FU NSERC [Rgpin 228738-03]; FQRNT; CIFAR; CFI
FX We acknowledge C. Winkler, INTEGRAL Project Scientist and the INTEGRAL
team for the quick ToO response; F. Haberl for useful discussions on how
to analyse the XMM-Newton timing data correctly. This work is supported
by NWO, Netherlands Organisation for Scientific Research. R. D. is
supported by the Natural Sciences and Engineering Research Council
(NSERC) PGSD scholarship. F. P. G. is supported by the NASA Postdoctoral
Program administered by Oak Ridge Associated Universities at NASA
Goddard Space-Flight Center. Additional support was provided by NSERC
Discovery Grant Rgpin 228738-03, FQRNT, CIFAR, and CFI. VMK holds a
Lorne Trottier Chair in Astrophysics & Cosmology, a Canada Research
Chair and is a R. Howard Webster Foundation Fellow of CIFAR. The results
are based on observations with INTEGRAL, an ESA project with instruments
and science data centre funded by ESA member states (especially the PI
countries: Denmark, France, Germany, Italy, Switzerland, Spain), Czech
Republic and Poland, and with the participation of Russia and the USA.
The SPI project has been completed under the responsibility and
leadership of CNES. We are grateful to ASI, CEA, CNES, DLR, ESA, INTA,
NASA and OSTC for support. This research has made use of data obtained
through the High-Energy Astrophysics Center Online Service, provided by
the NASA/Goddard Space-Flight Center.
NR 78
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PU EDP SCIENCES S A
PI LES ULIS CEDEX A
PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A,
FRANCE
SN 1432-0746
J9 ASTRON ASTROPHYS
JI Astron. Astrophys.
PD OCT
PY 2008
VL 489
IS 1
BP 245
EP 261
DI 10.1051/0004-6361:200809390
PG 17
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 350JA
UT WOS:000259347400021
ER
PT J
AU Tanaka, M
Finoguenov, A
Kodama, T
Morokuma, T
Rosati, P
Stanford, SA
Eisenhardt, P
Holden, B
Mei, S
AF Tanaka, M.
Finoguenov, A.
Kodama, T.
Morokuma, T.
Rosati, P.
Stanford, S. A.
Eisenhardt, P.
Holden, B.
Mei, S.
TI The environmental dependence of properties of galaxies around the
RDCSJ0910+54 cluster at z=1.1
SO ASTRONOMY & ASTROPHYSICS
LA English
DT Article
DE galaxies : evolution; galaxies : clusters : individual : DCSJ0910+54;
cosmology : large-scale structure of Universe
ID COLOR-MAGNITUDE RELATION; DIGITAL SKY SURVEY; HIGH-REDSHIFT CLUSTERS;
LARGE-SCALE STRUCTURES; LUMINOSITY FUNCTION; DENSITY RELATION;
STAR-FORMATION; LYNX SUPERCLUSTER; MASSIVE CLUSTER; POOR GROUPS
AB We report on the environmental dependence of properties of galaxies around the RDCSJ0910+ 54 cluster at z = 1.1. We obtained multi-band wide-field images of the cluster with Suprime-Cam and MOIRCS on Subaru and WFCAM on UKIRT. Also, an intensive spectroscopic campaign was carried out using LRIS on Keck and FOCAS on Subaru. We collected 161 spectra with secure redshifts, with which we calibrated a larger sample of photometric redshifts. We discover a possible large-scale structure around the cluster in the form of three clumps of galaxies. Two out of the three newly discovered clumps of galaxies are detected as extended X-ray sources, suggesting that they are bound systems. There seem to be filaments of galaxies in between the clumps. This is potentially one of the largest structures found so far in the z > 1 Universe. We then examined stellar populations of galaxies in the structure. First, we quantified the color-radius relation. Red galaxies have already become the dominant population in the cores of rich clusters at z similar to 1, and the fraction of red galaxies has not strongly changed since then. The red fraction depends on the richness of clusters in the sense that it is higher in rich clusters than in poor groups. We confirm that this trend is not due to possible biases in photometric redshifts. Next, we examined red sequence galaxies. The luminosity function of red galaxies in rich clusters is consistent with one in local clusters. On the other hand, the luminosity function of red galaxies in poor groups shows a deficit of faint red galaxies. This confirms our earlier findings that galaxies follow an environment-dependent down-sizing evolution. Interestingly, the truncation magnitude of the red sequence appears brighter than found in the RDCS J1252-29 field at z = 1.24. This suggests that there is a large variation in the evolutionary phases of galaxies in groups with similar masses. Further studies of high redshift clusters will be a promising way of addressing the role of nature and nurture effects in shaping the environmental dependence of galaxy properties observed in the local Universe.
C1 [Tanaka, M.; Rosati, P.] European So Observ, D-85748 Garching, Germany.
[Finoguenov, A.] Max Planck Inst Extraterr Phys, D-85748 Garching, Germany.
[Finoguenov, A.] Univ Maryland, Baltimore, MD 21250 USA.
[Kodama, T.; Morokuma, T.] Natl Astron Observ Japan, Mitaka, Tokyo 1818588, Japan.
[Stanford, S. A.] Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Livermore, CA 94550 USA.
[Stanford, S. A.] Univ Calif Davis, Dept Phys, Davis, CA 95616 USA.
[Eisenhardt, P.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[Holden, B.] Univ Calif Santa Cruz, Lick Observ, UCO, Santa Cruz, CA 95065 USA.
[Mei, S.] Univ Paris Denis Diderot, F-75205 Paris 13, France.
[Mei, S.] Observ Paris, Sect Meudon, GEPI, F-92195 Meudon, France.
RP Tanaka, M (reprint author), European So Observ, Karl Schwarzschild Str 2, D-85748 Garching, Germany.
EM mtanaka@eso.org
NR 57
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U1 0
U2 0
PU EDP SCIENCES S A
PI LES ULIS CEDEX A
PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A,
FRANCE
SN 1432-0746
J9 ASTRON ASTROPHYS
JI Astron. Astrophys.
PD OCT
PY 2008
VL 489
IS 2
BP 571
EP U43
DI 10.1051/0004-6361:200810440
PG 15
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 353XD
UT WOS:000259601500017
ER
PT J
AU Pinte, C
Padgett, DL
Menard, F
Stapelfeldt, KR
Schneider, G
Olofsson, J
Panic, O
Augereau, JC
Duchene, G
Krist, J
Pontoppidan, K
Perrin, MD
Grady, CA
Kessler-Silacci, J
van Dishoeck, EF
Lommen, D
Silverstone, M
Hines, DC
Wolf, S
Blake, GA
Henning, T
Stecklum, B
AF Pinte, C.
Padgett, D. L.
Menard, F.
Stapelfeldt, K. R.
Schneider, G.
Olofsson, J.
Panic, O.
Augereau, J. C.
Duchene, G.
Krist, J.
Pontoppidan, K.
Perrin, M. D.
Grady, C. A.
Kessler-Silacci, J.
van Dishoeck, E. F.
Lommen, D.
Silverstone, M.
Hines, D. C.
Wolf, S.
Blake, G. A.
Henning, T.
Stecklum, B.
TI Probing dust grain evolution in IM Lupi's circumstellar disc -
Multi-wavelength observations and modelling of the dust disc
SO ASTRONOMY & ASTROPHYSICS
LA English
DT Article
DE circumstellar matter; accretion, accretion disks; planetary systems :
protoplanetary disks; radiative transfer; stars : formation; pulsars :
individual : IM Lupi
ID T-TAURI STARS; MAIN-SEQUENCE STARS; INFRARED SPECTROGRAPH SPECTRA;
MICROSCOPII DEBRIS DISK; YOUNG STELLAR OBJECTS; SPITZER C2D SURVEY;
LOW-MASS STARS; PROTOPLANETARY DISKS; CRYSTALLINE SILICATES;
INTERSTELLAR GRAINS
AB Aims. We present a panchromatic study, involving a multiple technique approach, of the circumstellar disc surrounding the T Tauri star IM Lupi (Sz 82).
Methods. We have undertaken a comprehensive observational study of IM Lupi using photometry, spectroscopy, millimetre interferometry and multi-wavelength imaging. For the first time, the disc is resolved from optical and near-infrared wavelengths in scattered light, to the millimetre regime in thermal emission. Our data-set, in conjunction with existing photometric data, provides an extensive coverage of the spectral energy distribution, including a detailed spectrum of the silicate emission bands. We have performed a simultaneous modelling of the various observations, using the radiative transfer code MCFOST, and analysed a grid of models over a large fraction of the parameter space via Bayesian inference.
Results. We have constructed a model that can reproduce all of the observations of the disc. Our analysis illustrates the importance of combining a wide range of observations in order to fully constrain the disc model, with each observation providing a strong constraint only on some aspects of the disc structure and dust content. Quantitative evidence of dust evolution in the disc is obtained: grain growth up to millimetre-sized particles, vertical stratification of dust grains with micrometric grains close to the disc surface and larger grains which have settled towards the disc midplane, and possibly the formation of fluffy aggregates and/ or ice mantles around grains.
C1 [Pinte, C.] Univ Exeter, Sch Phys, Exeter EX4 4QL, Devon, England.
[Pinte, C.; Menard, F.; Olofsson, J.; Augereau, J. C.; Duchene, G.] CNRS, UJF, Lab Astrophys Grenoble, UMR 5571, F-38041 Grenoble 9, France.
[Padgett, D. L.] CALTECH, Spitzer Sci Ctr, Pasadena, CA 91125 USA.
[Stapelfeldt, K. R.; Krist, J.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[Schneider, G.] Univ Arizona, Steward Observ, Tucson, AZ 85721 USA.
[Panic, O.; van Dishoeck, E. F.; Lommen, D.] Leiden Univ, Leiden Observ, NL-2300 RA Leiden, Netherlands.
[Duchene, G.] Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA.
[Pontoppidan, K.; Blake, G. A.] CALTECH, Div Geol & Planetary Sci 150 21, Pasadena, CA 91125 USA.
[Perrin, M. D.] Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA.
[Grady, C. A.] Eureka Sci & Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
[Kessler-Silacci, J.] Univ Texas Austin, Dept Astron, Austin, TX 78712 USA.
[van Dishoeck, E. F.] Max Planck Inst Extraterr Phys, D-85748 Garching, Germany.
[Silverstone, M.] Eureka Sci Inc, NC Branch, Cary, NC 27513 USA.
[Hines, D. C.] Space Sci Inst, Corrales, NM 87048 USA.
[Wolf, S.] Univ Kiel, Inst Theoret Phys & Astrophys, D-24098 Kiel, Germany.
[Henning, T.] Max Planck Inst Astron, D-69117 Heidelberg, Germany.
[Stecklum, B.] Thuringer Landessternwarte Tautenburg, D-07778 Tautenburg, Germany.
RP Pinte, C (reprint author), Univ Exeter, Sch Phys, Stocker Rd, Exeter EX4 4QL, Devon, England.
EM pinte@astro.ex.ac.uk
RI Stapelfeldt, Karl/D-2721-2012
FU European Commission's Seventh Framework Program as a Marie Curie
Intra-European Fellow [PIEF-GA-2008-220891]; Agence Nationale pour la
Recherche (ANR) of France [ANR-07-BLAN-0221]; Association of
Universities for Research in Astronomy, Inc.; NASA contract [NAS
5-26555]; STScI; NASA [1224608, 1230779, 1256316]; NSF; Spitzer
Postdoctoral Fellowship Program; NWO Spinoza grant; NOVA; European
Research Training Network; PLANETS [HPRN-CT-2002-00308]; [G0/7387];
[GO/10177]
FX Authors would like to thank T. Hill for valuable comments on the
manuscript. Computations presented in this paper were performed at the
Service Commun de Calcul Intensif de l'Observatoire de Grenoble (SCCI)
and on the University of Exeter's SGI Altix ICE 8200 supercomputer. C.
Pinte acknowledges the funding from the European Commission's Seventh
Framework Program as a Marie Curie Intra-European Fellow
(PIEF-GA-2008-220891). The authors thank the Programme National de
Physique Stellaire (PNPS) and l'Action Specifique en Simulations
Numeriques pour l'Astronomie (ASSNA) of CNRS/ INSU, France and Agence
Nationale pour la Recherche (ANR) of France under contract
ANR-07-BLAN-0221, for supporting part of this research. This
investigation was based, in part, on observations made with the NASA/ESA
Hubble Space Telescope, obtained at the Space Telescope Science
Institute (STScI), which is operated by the Association of Universities
for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These
observations are associated with programs G0/7387 and GO/10177. Support
for these programs was provided by NASA through grants from STScI. This
research has made use of the SIMBAD database, operated at CDS,
Strasbourg, France, and data from the Two Micron All Sky Survey (U.
Mass, IPAC/CIT) funded by NASA and NSF. Support for this work, part of
the Spitzer Postdoctoral Fellowship Program, was provided by NASA
through contracts 1224608, 1230779 and 1256316, issued by the Jet
Propulsion Laboratory, California Institute of Technology, under NASA
contract 1407. Astrochemistry in Leiden is supported by a NWO Spinoza
grant and a NOVA grant, and by the European Research Training Network
"The Origin of Planetary Systems" (PLANETS, contract number
HPRN-CT-2002-00308).
NR 100
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PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A,
FRANCE
SN 1432-0746
J9 ASTRON ASTROPHYS
JI Astron. Astrophys.
PD OCT
PY 2008
VL 489
IS 2
BP 633
EP 650
DI 10.1051/0004-6361:200810121
PG 18
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 353XD
UT WOS:000259601500024
ER
PT J
AU Blay, P
Martinez-Nunez, S
Negueruela, I
Pottschmidt, K
Smith, DM
Torrejon, JM
Reig, P
Kretschmar, P
Kreykenbohm, I
AF Blay, P.
Martinez-Nunez, S.
Negueruela, I.
Pottschmidt, K.
Smith, D. M.
Torrejon, J. M.
Reig, P.
Kretschmar, P.
Kreykenbohm, I.
TI INTEGRAL long-term monitoring of the supergiant fast X-ray transient XTE
J1739-302
SO ASTRONOMY & ASTROPHYSICS
LA English
DT Article
DE binaries : close; supergiants; X-rays : binaries
ID HOT-STAR WINDS; NEUTRON-STAR; STELLAR WINDS; BINARIES; VARIABILITY;
TELESCOPE; ACCRETION; POROSITY; PULSARS
AB Context. In the past few years, a new class of high mass X-ray binaries (HMXRB) has been claimed to exist, the supergiant fast X-ray transients (SFXT). These are X-ray binary systems with a compact companion orbiting a supergiant star which show very short and bright outbursts in a series of activity periods overimposed on longer quiescent periods. Only very recently the first attempts to model the behaviour of these sources have been published, some of them within the framework of accretion from clumpy stellar winds.
Aims. Our goal is to analyze the properties of XTE J1739-302/IGR J17391-3021 within the context of the clumpy structure of the supergiant wind.
Methods. We have used INTEGRAL and RXTE/PCA observations to obtain broad band (1-200 keV) spectra and light curves of XTE J1739-302 and investigate its X-ray spectrum and temporal variability.
Results. We have found that XTE J1739-302 follows a much more complex behaviour than expected. Far from presenting a regular variability pattern, XTE J1739-302 shows periods of high, intermediate, and low flaring activity.
C1 [Blay, P.; Martinez-Nunez, S.] Univ Valencia, Inst Ciencia Mat, Valencia 46071, Spain.
[Martinez-Nunez, S.; Negueruela, I.; Torrejon, J. M.] Univ Alicante, Dept Fis Ingn Sistemas & Teor Senal, E-03080 Alicante, Spain.
[Pottschmidt, K.] Univ Maryland Baltimore Cty, CRESST, Baltimore, MD 21250 USA.
[Pottschmidt, K.] Univ Maryland Baltimore Cty, Dept Phys, Baltimore, MD 21250 USA.
[Pottschmidt, K.] NASA, Goddard Space Flight Ctr, Astrophys Sci Div, Greenbelt, MD 20771 USA.
[Smith, D. M.] Univ Calif Santa Cruz, Dept Phys, Santa Cruz, CA 95064 USA.
[Smith, D. M.] Univ Calif Santa Cruz, Santa Cruz Inst Particle Phys, Santa Cruz, CA 95064 USA.
[Torrejon, J. M.] MIT, Kavli Inst Astrophys & Space Res, Cambridge, MA 02139 USA.
[Reig, P.] Fdn Res & Technol, IESL, Iraklion 71110, Crete, Greece.
[Reig, P.] Univ Crete, Dept Phys, Iraklion 71003, Crete, Greece.
[Kretschmar, P.] ESAC, ESA, Madrid 28691, Spain.
[Kreykenbohm, I.] Inst Astron & Astrophys, Abt Astron, D-72076 Tubingen, Germany.
[Kreykenbohm, I.] INTEGRAL Sci Data Ctr, CH-1290 Versoix, Switzerland.
RP Blay, P (reprint author), Univ Valencia, Inst Ciencia Mat, POB 22085, Valencia 46071, Spain.
EM pere.blay@uv.es; ignacio@dfists.ua.es
RI Kreykenbohm, Ingo/H-9659-2013; Reig, Pablo/A-1198-2014; Negueruela,
Ignacio/L-5483-2014; Torrejon, Jose /K-6395-2014; Martinez-Nunez,
Silvia/K-3029-2014;
OI Kreykenbohm, Ingo/0000-0001-7335-1803; Reig, Pablo/0000-0002-6446-3050;
Negueruela, Ignacio/0000-0003-1952-3680; Torrejon, Jose
/0000-0002-5967-5163; Martinez-Nunez, Silvia/0000-0002-5134-4191;
Kretschmar, Peter/0000-0001-9840-2048
FU Spanish Ministerio de Educacion y Ciencia (MEC) [AYA2005-00095,
CSD2006-70, PR2007-0176]; University of Alicante; Generalitat Valenciana
and the European Regional Development Fund (ERDF/FEDER); European Union
Marie Curie [MTKD-CT-2006-039965]
FX Acknowledgements. We are grateful to Craig Markwardt for sharing RXTE
data durin the INTEGRAL KP2 period. S.M.N. is a researcher of the
Programme Juan de la Cierva, funded by the Spanish Ministerio de
Educacion y Ciencia (MEC) and the University of Alicante, with partial
support from the Generalitat Valenciana and the European Regional
Development Fund (ERDF/FEDER). This research is partially supported by
the MEC under grants AYA2005-00095 and CSD2006-70. J.M.T. aknowledges
the support by the Spanish Ministerio de Educacion y Ciencia (M.E.C.)
under grant PR2007-0176. P. R. acknowledges the support of the European
Union Marie Curie grant MTKD-CT-2006-039965. This research has made use
of data obtained through the INTEGRAL Science Data Center (ISDC),
Versoix, Switzerland.
NR 41
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SN 0004-6361
J9 ASTRON ASTROPHYS
JI Astron. Astrophys.
PD OCT
PY 2008
VL 489
IS 2
BP 669
EP 676
DI 10.1051/0004-6361:200809385
PG 8
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 353XD
UT WOS:000259601500027
ER
PT J
AU Massaro, F
Giommi, P
Tosti, G
Cassetti, A
Nesci, R
Perri, M
Burrows, D
Gerehls, N
AF Massaro, F.
Giommi, P.
Tosti, G.
Cassetti, A.
Nesci, R.
Perri, M.
Burrows, D.
Gerehls, N.
TI Swift observations of IBL and LBL objects
SO ASTRONOMY & ASTROPHYSICS
LA English
DT Article
DE galaxies : active; galaxies : BL Lacertae objects : general; X-rays :
galaxies; radiation mechanisms : non-thermal
ID BL-LACERTAE OBJECTS; X-RAY-SPECTRA; BLAZAR PKS 0537-441; XMM-NEWTON
OBSERVATIONS; ACTIVE GALACTIC NUCLEI; PHOTON IMAGING CAMERA; LAC
OBJECTS; MULTIFREQUENCY OBSERVATIONS; RADIO-SOURCES; OJ 287
AB Context. BL Lacs are an enigmatic class of active galactic nuclei (AGNs), characterized by the non-thermal continuum typically attributed to synchrotron and inverse Compton emission. Depending on the frequency location of the maxima of these components, they are subdivided into three subclasses LBLs, IBLs, and HBLs. We present the results of a set of observations of eight BL Lac objects of LBL and IBL type performed by the XRT and UVOT detectors onboard the Swift satellite between January 2005 and November 2006.
Aims. We are mainly interested in measuring the spectral parameters, and particularly the steepness between the UV and the X-ray band, useful for determining the classification of these sources. We compare the behavior of these sources with previous XMM-Newton, BeppoSAX observations and with historical data in the X-ray and in the optical band. We are also interested in classifying the sources in our sample on the basis of the Swift observations and comparing them with their classification presented in literature.
Methods. We performed X-ray spectral analysis of observed BL Lac objects using a simple powerlaw and in a few cases the log-parabolic model. We also combined the UV emission with the low energy X-ray data to describe their spectral energy distribution.
Results. We used Swift observational data to classify sources in our sample and derived parameters of their spectral energy distribution.
Conclusions. We found that for the IBLs X-rays low states show features of the high energy component, usually interpreted as due to inverse Compton emission. Sources in our sample exhibit a range of temporal UV and X-ray behaviors, some objects having clear and neat correlated UV and X-ray variations (e. g. ON231) and other objects showing no clear (e. g. AO 0235 + 164) UV and X-ray correlation. Finally, we also note that our estimates of spectral curvature are in the range of that measured for the High frequency peaked BL Lac objects (HBLs).
C1 [Massaro, F.] Univ Roma Tor Vergata, Dipartimento Fis, I-00133 Rome, Italy.
[Massaro, F.] Smithsonian Astrophys Observ, Cambridge, MA 02138 USA.
[Giommi, P.; Perri, M.] ESRIN, ASI Sci Data Ctr, I-00044 Frascati, Italy.
[Tosti, G.] Univ Perugia, Dipartimento Fis, I-06123 Perugia, Italy.
[Cassetti, A.; Nesci, R.] Univ Roma La Sapienza, Dipartimento Fis, I-00185 Rome, Italy.
[Burrows, D.] Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA.
[Gerehls, N.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
RP Massaro, F (reprint author), Univ Roma Tor Vergata, Dipartimento Fis, Via Ric Sci 1, I-00133 Rome, Italy.
EM fmassaro@cfa.harvard.edu
RI Tosti, Gino/E-9976-2013; Massaro, Francesco/L-9102-2016;
OI Massaro, Francesco/0000-0002-1704-9850; giommi,
paolo/0000-0002-2265-5003; Perri, Matteo/0000-0003-3613-4409
FU National Aeronautics and Space Administration
FX We thank our referee E. Pian for helpful comments improving our
presentation. F. Massaro thanks G. Cusumano for his help in the use of
the Swift-XRT data reduction procedure, and A. Tramacere for his
suggestions and discussions on the use of XMM-Newton SAS software. We
thank S. Ciprini for helpful discussion of OJ 287 XMM-Newton
observations. This research has made use of the NASA/IPAC Extragalactic
Database (NED), which is operated by the Jet Propulsion Laboratory,
California Institute of Technology, under contract with the National
Aeronautics and Space Administration.
NR 58
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SN 0004-6361
J9 ASTRON ASTROPHYS
JI Astron. Astrophys.
PD OCT
PY 2008
VL 489
IS 3
BP 1047
EP 1054
DI 10.1051/0004-6361:200809824
PG 8
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 356DZ
UT WOS:000259760200018
ER
PT J
AU Mengel, S
Lehnert, MD
Thatte, NA
Vacca, WD
Whitmore, B
Chandar, R
AF Mengel, S.
Lehnert, M. D.
Thatte, N. A.
Vacca, W. D.
Whitmore, B.
Chandar, R.
TI Young star clusters in interacting galaxies - NGC 1487 and NGC 4038/4039
SO ASTRONOMY & ASTROPHYSICS
LA English
DT Article
DE galaxies : interactions; galaxies : star clusters
ID SPACE-TELESCOPE OBSERVATIONS; GLOBULAR-CLUSTERS; ANTENNAE GALAXIES; MASS
FUNCTION; DYNAMICAL EVOLUTION; LUMINOSITY FUNCTION; STELLAR CLUSTERS;
SPIRAL GALAXIES; AGE DISTRIBUTION; GAS EXPULSION
AB We estimate the dynamical masses of several young (approximate to 10 Myr) massive star clusters in two interacting galaxies, NGC 4038/4039 ("The Antennae") and NGC 1487, under the assumption of virial equilibrium. These are compared with photometric mass estimates from K-band photometry assuming a standard Kroupa IMF. The clusters were selected to have near-infrared colours dominated by red supergiants, hence old enough to have survived the earliest phases of cluster evolution when the interstellar medium is rapidly swept out from the cluster, supported by there being no obvious H alpha emission associated with the clusters. All but one of the Antennae clusters have dynamical and photometric mass estimates that are within a factor approximate to 2 of one another, implying both that standard IMFs provide a good approximation to the IMF of these clusters and that there is no significant extra-virial motion, as would be expected if they were rapidly dispersing. These results suggest that almost all of the Antennae clusters in our sample have survived the gas removal phase as bound or marginally bound objects. Two of the three NGC 1487 clusters studied here have M(dyn) estimates that are significantly greater than the photometric mass estimates. At least one of these two clusters, and one in the Antennae, may be actively in the process of dissolving. The process of dissolution contributes a component of non-virial motion to the integrated velocity measurements, resulting in an estimated M(dyn) that is too high relative to the amount of measured stellar light. The dissolution candidates in both galaxies are amongst the clusters with the lowest pressures/densities measured in our sample.
C1 [Mengel, S.] European So Observ, D-85748 Garching, Germany.
[Lehnert, M. D.] Univ Paris 07, CNRS, Observ Paris, F-92190 Meudon, France.
[Thatte, N. A.] Univ Oxford, Dept Astrophys, Oxford OX1 3RH, England.
[Vacca, W. D.] Univ Space Res Assoc, NASA, Ames Res Ctr, Stratospher Observ Infrared Astron, Moffett Field, CA 94035 USA.
[Whitmore, B.] Space Telescope Sci Inst, Baltimore, MD 21218 USA.
[Chandar, R.] Univ Toledo, Toledo, OH 43606 USA.
RP Mengel, S (reprint author), European So Observ, Karl Schwarzschild Str 2, D-85748 Garching, Germany.
EM smengel@eso.org; matthew.lehnert@obspm.fr; thatte@astro.ox.ac.uk;
wvacca@sofia.usra.edu; whitmore@stsci.edu; Rupali.Chandar@utoledo.edu
NR 80
TC 29
Z9 29
U1 0
U2 1
PU EDP SCIENCES S A
PI LES ULIS CEDEX A
PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A,
FRANCE
SN 0004-6361
J9 ASTRON ASTROPHYS
JI Astron. Astrophys.
PD OCT
PY 2008
VL 489
IS 3
BP 1091
EP 1105
DI 10.1051/0004-6361:200809649
PG 15
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 356DZ
UT WOS:000259760200023
ER
PT J
AU Pandian, JD
Leurini, S
Menten, KM
Belloche, A
Goldsmith, PF
AF Pandian, J. D.
Leurini, S.
Menten, K. M.
Belloche, A.
Goldsmith, P. F.
TI Detection of 6.7 GHz methanol absorption towards hot corinos
SO ASTRONOMY & ASTROPHYSICS
LA English
DT Article
DE masers; stars : low-mass, brown dwarfs
ID PROTOSTAR NGC-1333 IRAS-4A; STAR-FORMING REGIONS; LOW-MASS PROTOSTARS;
INTERSTELLAR METHANOL; MOLECULAR CLOUDS; DIAGNOSTIC-TOOL; MASERS; CORE;
TRANSITION; APEX
AB Context. Methanol masers at 6.7 GHz have been found exclusively towards high-mass star forming regions. Recently, some Class 0 protostars have been found to display conditions similar to what are found in hot cores that are associated with massive star formation. These hot corino sources have densities, gas temperatures, and methanol abundances that are adequate for exciting strong 6.7 GHz maser emission.
Aims. This raises the question of whether 6.7 GHz methanol masers can be found in both hot corinos and massive star forming regions, and if not, whether thermal methanol emission can be detected.
Methods. We searched for the 6.7 GHz methanol line towards five hot corino sources in the Perseus region using the Arecibo radio telescope. To constrain the excitation conditions of methanol, we observed thermal submillimeter lines of methanol in the NGC 1333-IRAS 4 region with the APEX telescope.
Results. We did not detect 6.7 GHz emission in any of the sources, but found absorption against the cosmic microwave background in NGC 1333-IRAS 4A and NGC 1333-IRAS 4B. Using a large velocity gradient analysis, we modeled the excitation of methanol over a wide range of physical parameters, and verify that the 6.7 GHz line is indeed strongly anti-inverted for densities lower than 10(6) cm(-3). We used the submillimeter observations of methanol to verify the predictions of our model for IRAS 4A by comparison with other CH(3)OH transitions. Our results indicate that the methanol observations from the APEX and Arecibo telescopes are consistent with dense (n similar to 106 cm(-3)), cold (T similar to 15-30 K) gas.
Conclusions. The lack of maser emission in hot corinos and low-mass protostellar objects in general may be due to densities that are much higher than the quenching density in the region where the radiation field is conducive to maser pumping.
C1 [Pandian, J. D.; Menten, K. M.; Belloche, A.] Max Planck Inst Radioastron, D-53121 Bonn, Germany.
[Leurini, S.] ESO, D-85748 Garching, Germany.
[Goldsmith, P. F.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Pandian, JD (reprint author), Max Planck Inst Radioastron, Hugel 69, D-53121 Bonn, Germany.
EM jpandian@mpifr-bonn.mpg.de; sleurini@eso.org; kmenten@mpifr-bonn.mpg.de;
belloche@mpifr-bonn.mpg.de; Paul.F.Goldsmith@jpl.nasa.gov
RI Goldsmith, Paul/H-3159-2016
FU Jet Propulsion Laboratory, California Institute of Technology
FX This work was supported in part by the Jet Propulsion Laboratory,
California Institute of Technology, under a contract with the National
Aeronautics and Space Administration. This research has made use of
NASA's Astrophysics Data System.
NR 42
TC 8
Z9 8
U1 0
U2 1
PU EDP SCIENCES S A
PI LES ULIS CEDEX A
PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A,
FRANCE
SN 0004-6361
J9 ASTRON ASTROPHYS
JI Astron. Astrophys.
PD OCT
PY 2008
VL 489
IS 3
BP 1175
EP 1182
DI 10.1051/0004-6361:200810556
PG 8
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 356DZ
UT WOS:000259760200030
ER
PT J
AU Martin-Hernandez, NL
Peeters, E
Tielens, AGGM
AF Martin-Hernandez, N. L.
Peeters, E.
Tielens, A. G. G. M.
TI A mid-infrared study of HII regions in the Magellanic Clouds: N88 A and
N160 A
SO ASTRONOMY & ASTROPHYSICS
LA English
DT Article
DE ISM : lines and bands; ISM : dust, extinction; ISM : HII regions; ISM :
individual objects : N88A; infrared : ISM; ISM : individual objects :
N160A
ID SPITZER-SPACE-TELESCOPE; STAR-FORMING REGION; H-II REGIONS; INFRARED
OBSERVATIONS; PHYSICAL-PROPERTIES; MILKY-WAY; O-STARS; SPECTROSCOPY;
EXCITATION; EMISSION
AB Aims. To show the importance of high-spatial resolution observations of HII regions when compared with observations obtained with larger apertures such as ISO, we present mid-infrared spectra of two Magellanic Cloud HII regions, N88A and N160 A.
Methods. We obtained mid-infrared (8-13 mu m), long-slit spectra with TIMMI2 on the ESO 3.6 m telescope. These are combined with archival spectra obtained with the Infrared Spectrograph (IRS) onboard the Spitzer Space Telescope, and are compared with the low-spatial resolution ISO-SWS data. An inventory of the spectra in terms of atomic fine-structure lines and molecular bands is presented.
Results. Concerning N88 A, an isolated HII region with no adjacent infrared sources, the observations indicate that the line fluxes observed by ISO-SWS and Spitzer-IRS come exclusively from the compact HII region of about 3 '' in diameter. This is not the case for N160 A, which has a more complex morphology. We have spectroscopically isolated for the first time the individual contributions of the three components of N160 A, two high-excitation blobs, A1 and A2, and the young stellar object (YSO) N160 A-IR. In addition, extended [SIV] emission is observed with TIMMI2 and is most likely associated with the central star cluster located between A1 and A2. We show the value of these high-spatial resolution data in determining source characteristics, such as the degree of ionization of each high-excitation blob or the bolometric luminosity of the YSO. This luminosity (2 x 10(5) L(circle dot)) is about one order of magnitude lower than previously estimated. For each high-excitation blob, we also determine the electron density and the elemental abundances of Ne, S, and Ar.
C1 [Martin-Hernandez, N. L.] Inst Astrofis Canarias, San Cristobal la Laguna 38205, Spain.
[Peeters, E.] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
[Peeters, E.] SETI Inst, Mountain View, CA 94043 USA.
[Peeters, E.] Univ Western Ontario, Dept Phys & Astron, London, ON N6A 3K7, Canada.
[Tielens, A. G. G. M.] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
RP Martin-Hernandez, NL (reprint author), Inst Astrofis Canarias, Via Lactea S-N, San Cristobal la Laguna 38205, Spain.
EM leticia@iac.es
FU ESA Member States; Spanish Ministerio de Ciencia y Tecnologia (MCyT);
Spanish MCyT [AYA2004-07466]
FX This work is based on observations obtained at the European Southern
Observatory, La Silla, Chile (ID 72.C-0600) and observations made with
the Spitzer Space Telescope, which is operated by the Jet Propulsion
Laboratory, California Institute of Technology under a contract with
NASA. It is also based on observations with ISO, an ESA project with
instruments funded by ESA Member States (especially the PI countries:
France, Germany, the Netherlands and the United Kingdom) and with the
participation of ISAS and NASA. During this work, NLMH has been
supported by a Juan de la Cierva fellowship from the Spanish Ministerio
de Ciencia y Tecnologia (MCyT). This work has also been partially funded
by the Spanish MCyT under project AYA2004-07466.
NR 48
TC 2
Z9 2
U1 0
U2 1
PU EDP SCIENCES S A
PI LES ULIS CEDEX A
PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A,
FRANCE
SN 0004-6361
J9 ASTRON ASTROPHYS
JI Astron. Astrophys.
PD OCT
PY 2008
VL 489
IS 3
BP 1189
EP 1200
DI 10.1051/0004-6361:200810341
PG 12
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 356DZ
UT WOS:000259760200032
ER
PT J
AU Anzolin, G
de Martino, D
Bonnet-Bidaud, JM
Mouchet, M
Gansicke, BT
Matt, G
Mukai, K
AF Anzolin, G.
de Martino, D.
Bonnet-Bidaud, J. -M.
Mouchet, M.
Gaensicke, B. T.
Matt, G.
Mukai, K.
TI Two new intermediate polars with a soft X-ray component
SO ASTRONOMY & ASTROPHYSICS
LA English
DT Article
DE stars : binaries : close; stars : individual : 1RXS J070407.9+262501;
stars : individual : 1RXS 180340.0+401214; stars : novae, cataclysmic
variables; X-rays : stars; accretion, accretion disks
ID ALL-SKY SURVEY; MAGNETIC CATACLYSMIC VARIABLES; PHOTON IMAGING CAMERA;
XMM-NEWTON; WHITE-DWARFS; PQ GEM; FO-AQR; ACCRETION; EMISSION; DISCOVERY
AB Aims. We analyze the first X-ray observations with XMM-Newton of 1RXS J070407.9+262501 and 1RXS 180340.0+401214, in order to characterize their broad-band temporal and spectral properties, also in the UV/optical domain, and to confirm them as intermediate polars.
Methods. For both objects, we performed a timing analysis of the X-ray and UV/optical light curves to detect the white dwarf spin pulsations and study their energy dependence. For 1RXS 180340.0+401214 we also analyzed optical spectroscopic data to determine the orbital period. X-ray spectra were analyzed in the 0.2-10.0 keV range to characterize the emission properties of both sources.
Results. We find that the X-ray light curves of both systems are energy dependent and are dominated, below 3-5 keV, by strong pulsations at the white dwarf rotational periods (480 s for 1RXS J070407.9+262501 and 1520.5 s for 1RXS 180340.0+401214). In 1RXS 180340.0+401214 we also detect an X-ray beat variability at 1697 s which, together with our new optical spectroscopy, favours an orbital period of 4.4 h that is longer than previously estimated. Both systems show complex spectra with a hard (temperature up to 40 keV) optically thin and a soft (kT similar to 85-100 eV) optically thick components heavily absorbed by material partially covering the X-ray sources.
Conclusions. Our observations confirm the two systems as intermediate polars and also add them as new members of the growing group of "soft" systems which show the presence of a soft X-ray blackbody component. Differences in the temperatures of the blackbodies are qualitatively explained in terms of reprocessing over different sizes of the white dwarf spot. We suggest that systems showing cooler soft X-ray blackbody components also possess white dwarfs irradiated by cyclotron radiation.
C1 [Anzolin, G.] Univ Padua, Dipartimento Astron, I-35122 Padua, Italy.
[Anzolin, G.; de Martino, D.] Osserv Astron Capodimonte, INAF, I-80131 Naples, Italy.
[Bonnet-Bidaud, J. -M.] CE Saclay, SAp, DAPNIA, DSM,Serv Astrophys, F-91191 Gif Sur Yvette, France.
[Mouchet, M.] Univ Paris 07, Lab Astroparticule & Cosmol, F-75005 Paris, France.
[Mouchet, M.] Observ Paris, LUTH, F-92195 Meudon, France.
[Gaensicke, B. T.] Univ Warwick, Dept Phys, Coventry CV4 7AL, W Midlands, England.
[Matt, G.] Univ Roma Tre, Dipartimento Fis, I-00146 Rome, Italy.
[Mukai, K.] NASA, Goddard Space Flight Ctr, CRESST, Greenbelt, MD 20771 USA.
[Mukai, K.] NASA, Goddard Space Flight Ctr, Xray Astrophys Lab, Greenbelt, MD 20771 USA.
[Mukai, K.] Univ Maryland, Dept Phys, Baltimore, MD 21250 USA.
RP Anzolin, G (reprint author), Univ Padua, Dipartimento Astron, Vicolo Osservatorio 3, I-35122 Padua, Italy.
EM gabriele.anzolin@unipd.it; demartino@oacn.inaf.it; bonnetbidaud@cea.fr;
martine.mouchet@obspm.fr; boris.gaensicke@warwick.ac.uk;
matt@fis.uniroma3.it; koji.mukai@nasa.gov
RI Gaensicke, Boris/A-9421-2012;
OI Gaensicke, Boris/0000-0002-2761-3005; de Martino,
Domitilla/0000-0002-5069-4202
FU ASI [ASI/INAFI/023/05/06]; INAF [PRIN-INAF2007 N.17]
FX We acknowledge the XMM-Newton SOC and MSSL staff for help in the
reprocessing of the OM data. Prof. A. Bianchini is gratefully
acknowledged for useful discussion. D.d.M. and G. A. acknowledge
financial support from ASI under contract ASI/INAFI/023/05/06 and from
INAF under contract PRIN-INAF2007 N.17.
NR 54
TC 26
Z9 26
U1 0
U2 0
PU EDP SCIENCES S A
PI LES ULIS CEDEX A
PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A,
FRANCE
SN 1432-0746
J9 ASTRON ASTROPHYS
JI Astron. Astrophys.
PD OCT
PY 2008
VL 489
IS 3
BP 1243
EP 1254
DI 10.1051/0004-6361:200810402
PG 12
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 356DZ
UT WOS:000259760200039
ER
PT J
AU Wang, TJ
Solanki, SK
Selwa, M
AF Wang, T. J.
Solanki, S. K.
Selwa, M.
TI Identification of different types of kink modes in coronal loops:
principles and application to TRACE results
SO ASTRONOMY & ASTROPHYSICS
LA English
DT Article
DE Sun : corona; Sun : flares; Sun : oscillations; Sun : UV radiation
ID FAST MAGNETOHYDRODYNAMIC OSCILLATIONS; FAST MAGNETOACOUSTIC WAVES;
TRANSVERSE OSCILLATIONS; VERTICAL OSCILLATIONS; NUMERICAL SIMULATIONS;
MAGNETIC-FIELD; SUMER; ARCADE; BRIGHTENINGS; PROPAGATION
AB We explore the possible observational signatures of different types of kink modes (horizontal and vertical oscillations in their fundamental mode and second harmonic) that may arise in coronal loops, with the aim of determining how well the individual modes can be uniquely identified from time series of images. A simple, purely geometrical model is constructed to describe the different types of kink-mode oscillations. These are then "observed" from a given direction. In particular, we employ the 3D geometrical parameters of 14 TRACE loops of transverse oscillations to try to identify the correct observed wave mode. We find that for many combinations of viewing and loop geometry it is not straightforward to distinguish between at least two types of kink modes just using time series of images. We also considered Doppler signatures and find that these can help obtain unique identifications of the oscillation modes when employed in combination with imaging. We then compare the modeled spatial signatures with the observations of 14 TRACE loops. We find that out of three oscillations previously identified as fundamental horizontal mode oscillations, two cases appear to be fundamental vertical mode oscillations (but possibly combined with the fundamental horizontal mode), and one case appears to be a combination of the fundamental vertical and horizontal modes, while in three cases it is not possible to clearly distinguish between the fundamental mode and the second-harmonic of the horizontal oscillation. In five other cases it is not possible to clearly distinguish between a fundamental horizontal mode and the second-harmonic of a vertical mode.
C1 [Wang, T. J.; Selwa, M.] Catholic Univ Amer, Dept Phys, Greenbelt, MD 20771 USA.
[Wang, T. J.; Selwa, M.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
[Wang, T. J.] Montana State Univ, Dept Phys, Bozeman, MT 59717 USA.
[Solanki, S. K.] Max Planck Inst Sonnensyst Forsch, D-37191 Katlenburg Lindau, Germany.
RP Wang, TJ (reprint author), Catholic Univ Amer, Dept Phys, Code 671, Greenbelt, MD 20771 USA.
EM wangtj@helio.gsfc.nasa.gov
RI Solanki, Sami/E-2487-2013
OI Solanki, Sami/0000-0002-3418-8449
FU NRL [N00173-06-1G033]; NASA [NNG06GA37G, NAS5-38099, NNG06GI55G];
Montana State University
FX T.J.W.'s work was supported by NRL grant N00173-06-1G033, NASA grant
NNG06GA37G, and NASA grant NAS5-38099 for TRACE mission operations and
data analysis, through a subcontract of Lockheed-Martin Solar and
Astrophysics Laboratory with Montana State University. M.S.'s work was
supported by the NASA grant SEC theory program and NASA grant
NNG06GI55G. The authors also thank the anonymous referee for his
constructive comments.
NR 47
TC 23
Z9 23
U1 0
U2 2
PU EDP SCIENCES S A
PI LES ULIS CEDEX A
PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A,
FRANCE
SN 0004-6361
J9 ASTRON ASTROPHYS
JI Astron. Astrophys.
PD OCT
PY 2008
VL 489
IS 3
BP 1307
EP 1317
DI 10.1051/0004-6361:200810230
PG 11
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 356DZ
UT WOS:000259760200045
ER
PT J
AU Perucho, M
Agudo, I
Gomez, JL
Kadler, M
Ros, E
Kovalev, YY
AF Perucho, M.
Agudo, I.
Gomez, J. L.
Kadler, M.
Ros, E.
Kovalev, Y. Y.
TI On the nature of an ejection event in the jet of 3C 111
SO ASTRONOMY & ASTROPHYSICS
LA English
DT Article
DE galaxies : individual : 3C 111; galaxies : active; galaxies : nuclei;
galaxies : jets
ID ACTIVE GALACTIC NUCLEI; SUPERLUMINAL SOURCES; RELATIVISTIC JETS;
COMPONENTS; STABILITY; MODELS; GALAXY
AB We present a possible scenario for the ejection of a superluminal component in the jet of the Broad Line Radio Galaxy 3C 111 in early 1996. VLBI observations at 15 GHz discovered the presence of two jet features on scales smaller than one parsec. The first component evolves downstream, whereas the second one fades out after 1 parsec. We propose the injection of a perturbation of dense material followed by a decrease in the injection rate of material in the jet as a plausible explanation. This scenario is supported by 1D relativistic hydrodynamic and emission simulations. The perturbation is modeled as an increase in the jet density, without modifying the original Lorentz factor in the initial conditions. We show that an increase of the Lorentz factor in the material of the perturbation fails to reproduce the observed evolution of this flare. We are able to estimate the lifetime of the ejection event in 3C 111 to be 36 +/- 7 days.
C1 [Perucho, M.; Ros, E.; Kovalev, Y. Y.] Max Planck Inst Radioastron, D-53121 Bonn, Germany.
[Agudo, I.; Gomez, J. L.] CSIC, Inst Astrofis Andalucia, E-18080 Granada, Spain.
[Kadler, M.] Univ Erlangen Nurnberg, Dr Karl Remeis Observ, D-96049 Bamberg, Germany.
[Kadler, M.] NASA, Goddard Space Flight Ctr, CRESST, Greenbelt, MD 20771 USA.
[Kadler, M.] Univ Space Res Assoc, Columbia, MD 21044 USA.
[Kovalev, Y. Y.] PN Lebedev Phys Inst, Ctr Astro Space, Moscow 117997, Russia.
RP Perucho, M (reprint author), Max Planck Inst Radioastron, Hugel 69, D-53121 Bonn, Germany.
EM perucho@mpifr-bonn.mpg.de
RI Kovalev, Yuri/J-5671-2013; Agudo, Ivan/G-1701-2015; Perucho,
Manel/A-9528-2017
OI Ros, Eduardo/0000-0001-9503-4892; Kadler, Matthias/0000-0001-5606-6154;
Kovalev, Yuri/0000-0001-9303-3263; Agudo, Ivan/0000-0002-3777-6182;
Perucho, Manel/0000-0003-2784-0379
FU "Generalitat Valenciana" ("Beca Postdoctoral d'Excel.lencia"); Spanish
"Ministerio de Educacion y Ciencia; European Fund for Regional
Development [AYA2007-67627-C03-01, AYA2007-67752-C03- 02]; IA; JLG
[AYA2007-67627-C03-03]; NASA Postdoctoral Program at the Goddard Space
Flight Center; Alexander von Humboldt Foundation
FX M. P. acknowledges support from a postdoctoral fellowship of the
"Generalitat Valenciana" ("Beca Postdoctoral d'Excel center dot
lencia"). I. A. is supported by an I3P contract with the Spanish
"Consejo Superior de Investigaciones Cientificas". M. P. acknowledges
support by the Spanish "Ministerio de Educacion y Ciencia" and the
European Fund for Regional Development through grants
AYA2007-67627-C03-01 and AYA2007-67752-C03- 02 and IA and JLG through
grant AYA2007-67627-C03-03. M. K. has been supported by the NASA
Postdoctoral Program at the Goddard Space Flight Center, administered by
the Oak Ridge Associated Universities through a contract with NASA. Y.
K. is a research fellow of the Alexander von Humboldt Foundation. The
authors thank J. M. Marti, A. P. Marscher and M. A. Aloy for useful
discussion and comments. The authors thank C. Fromm for his help with
figures.
NR 16
TC 7
Z9 7
U1 0
U2 0
PU EDP SCIENCES S A
PI LES ULIS CEDEX A
PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A,
FRANCE
SN 0004-6361
J9 ASTRON ASTROPHYS
JI Astron. Astrophys.
PD OCT
PY 2008
VL 489
IS 2
BP L29
EP L32
DI 10.1051/0004-6361:200810479
PG 4
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 353XD
UT WOS:000259601500007
ER
PT J
AU Demidov, NE
Boynton, WV
Gilichinsky, DA
Zuber, MT
Kozyrev, AS
Litvak, ML
Mitrofanov, IG
Sanin, AB
Saunders, RS
Smith, DE
Tretyakov, VI
Hamara, D
AF Demidov, N. E.
Boynton, W. V.
Gilichinsky, D. A.
Zuber, M. T.
Kozyrev, A. S.
Litvak, M. L.
Mitrofanov, I. G.
Sanin, A. B.
Saunders, R. S.
Smith, D. E.
Tretyakov, V. I.
Hamara, D.
TI Water distribution in Martian permafrost regions from joint analysis of
HEND (Mars Odyssey) and MOLA (Mars Global Surveyor) data
SO ASTRONOMY LETTERS-A JOURNAL OF ASTRONOMY AND SPACE ASTROPHYSICS
LA English
DT Article
DE Mars; neutron spectroscopy; albedo; water ice
ID ENERGY NEUTRON DETECTOR; NEAR-SURFACE; ICE; STABILITY; HYDROGEN; HISTORY
AB We jointly analyze data from the High-Energy Neutron Detector (HEND) onboard the NASA Mars Odyssey spacecraft and data from the Mars Orbiter Laser Altimeter (MOLA) onboard the Mars Global Surveyor spacecraft. The former instrument measures the content of hydrogen (in the form of H2O or OH) in the subsurface layer of soil and the latter instrument measures the surface albedo with respect to the flux of solar energy. We have checked the presence of a correlation between these two data sets in various Martian latitude bands. A significant correlation has been found between these data at latitudes poleward of 40 degrees in the northern hemisphere and at latitudes 40 degrees -60 degrees in the southern hemisphere. This correlation is interpreted as evidence for the presence of stable water ice in these regions under a dry layer of soil whose thickness is determined by the condition for equilibrium between the condensation of water from the atmosphere and its sublimation when heated by solar radiation. For these regions, we have derived an empirical relation between the flux of absorbed solar radiation and the thickness of the top dry layer. It allows the burial depth of the water ice table to be predicted with a sub-kilometer resolution based on near-infrared albedo measurements. We have found no correlation in the southern hemisphere at latitudes >60 degrees, although neutron data also suggest that water ice is present in this region under a layer of dry soil. We conclude that the thickness of the dry layer in this region does not correspond to the equilibrium condition between the water ice table and the atmosphere.
C1 [Demidov, N. E.; Gilichinsky, D. A.] Russian Acad Sci, Inst Phys Chem & Biol Problems Soil Sci, Pushchino 142292, Russia.
[Boynton, W. V.; Hamara, D.] Univ Arizona, Tucson, AZ USA.
[Zuber, M. T.] MIT, Dept Earth Atmospher & Planetary Sci, Cambridge, MA USA.
[Kozyrev, A. S.; Litvak, M. L.; Mitrofanov, I. G.; Sanin, A. B.; Tretyakov, V. I.] Russian Acad Sci, Space Res Inst, Moscow 117997, Russia.
[Saunders, R. S.] NASA Headquarters, Washington, DC USA.
[Smith, D. E.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
RP Demidov, NE (reprint author), Russian Acad Sci, Inst Phys Chem & Biol Problems Soil Sci, Pushchino 142292, Russia.
EM nikdemidov@mail.ru
FU Program of the Russian President [02.120.11.19015]; Young Russian
Scientists [MD-265.2007.2]
FX We are grateful to the Program of the Russian President (project no.
02.120.11.19015) for Support of Young Russian Scientists
(MD-265.2007.2).
NR 29
TC 3
Z9 3
U1 1
U2 5
PU MAIK NAUKA/INTERPERIODICA/SPRINGER
PI NEW YORK
PA 233 SPRING ST, NEW YORK, NY 10013-1578 USA
SN 1063-7737
J9 ASTRON LETT+
JI Astron. Lett.-J. Astron. Space Astrophys.
PD OCT
PY 2008
VL 34
IS 10
BP 713
EP 723
DI 10.1134/S1063773708100071
PG 11
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 353GW
UT WOS:000259555100007
ER
PT J
AU Kataoka, J
Stawarz, L
Harris, DE
Siemiginowska, A
Ostrowski, M
Swain, MR
Hardcastle, MJ
Goodger, JL
Iwasawa, K
Edwards, PG
AF Kataoka, J.
Stawarz, L.
Harris, D. E.
Siemiginowska, A.
Ostrowski, M.
Swain, M. R.
Hardcastle, M. J.
Goodger, J. L.
Iwasawa, K.
Edwards, P. G.
TI Chandra reveals twin X-ray jets in the powerful FR II radio galaxy 3C
353
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE galaxies : active; galaxies : individual (3C 353); galaxies : jets;
radiation mechanisms : nonthermal; X-rays : general
ID LARGE-SCALE JETS; HUBBLE-SPACE-TELESCOPE; SHEATH RELATIVISTIC JETS;
ACTIVE GALACTIC NUCLEI; EXTRAGALACTIC JETS; HOT-SPOTS;
PARTICLE-ACCELERATION; ENERGY-DISTRIBUTION; DYNAMICAL MODELS;
CENTAURUS-A
AB We report X-ray imaging of the powerful FR II radio galaxy 3C 353 using the Chandra X-Ray Observatory. Due to 3C 353's two 4 '' wide and 2' long jets we are able to study in detail the internal structure of the large-scale relativistic outflows at both radio and X-ray photon energies with the subarcsecond spatial resolution provided by the VLA and Chandra instruments. In a 90 ks Chandra observation, we have detected X-ray emission from most radio structures in 3C 353, including the nucleus, the jet and the counterjet, the terminal jet regions (hot spots), and one radio lobe. We show that the detection of the X-ray emission associated with the radio knots and counterknots, which is most likely nonthermal in origin, puts several crucial constraints on the X-ray emission mechanisms in powerful large-scale jets of quasars and FR II sources. In particular, we show that this detection is inconsistent with the inverse-Compton model proposed in the literature and instead implies a synchrotron origin of the X-ray jet photons. We also find that the width of the X-ray counterjet is possibly narrower than that measured in radio bands, that the radio to X-ray flux ratio decreases systematically downstream along the jets, and that there are substantial (kpc-scale) offsets between the positions of the X-ray and radio intensity maxima within each knot, whose magnitudes increase away from the nucleus. We discuss all these findings in the wider context of the physics of extragalactic jets, proposing some particular although not definitive solutions or interpretations for each problem. In general, we find that the synchrotron X-ray emission of extragalactic large-scale jets is not only shaped by the global hydrodynamical configuration of the outflows, but is also likely to be very sensitive to the microscopic parameters of the jet plasma. A complete, self-consistent model for the X-ray emission of extragalactic jets still remains elusive.
C1 [Kataoka, J.] Tokyo Inst Technol, Dept Phys, Meguro Ku, Tokyo 1528551, Japan.
[Stawarz, L.] Stanford Univ, Kavli Inst Particle Astrophys & Cosmol, Stanford, CA 94305 USA.
[Stawarz, L.; Ostrowski, M.] Jagiellonian Univ, Astron Observ, PL-30244 Krakow, Poland.
[Harris, D. E.; Siemiginowska, A.] Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA.
[Swain, M. R.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[Goodger, J. L.] Univ Hertfordshire, Hatfield AL10 9AB, Herts, England.
[Iwasawa, K.] INAF Osservatorio Astron Bologna, I-40127 Bologna, Italy.
[Edwards, P. G.] CSIRO, Australia Telescope Natl Facil, Narrabri, NSW 2390, Australia.
RP Kataoka, J (reprint author), Tokyo Inst Technol, Dept Phys, Meguro Ku, 2-12-1 Ohokayama, Tokyo 1528551, Japan.
RI Hardcastle, Martin/E-2264-2012;
OI Hardcastle, Martin/0000-0003-4223-1117; Goodger,
Joanna/0000-0002-5738-4768
FU Japanese Society for the Promotion of Science (JSPS) [19204017]; Polish
Ministry of Education and Science (MEiN) [1-P03D-003-29]; Royal Society;
National Aeronautics and Space Administration (NASA) [NAS8-39073]; NASA
[GO5-6113X, GO7-8103X-R]; Chandra X-Ray Observatory Center [NAS8-39073]
FX J. K. acknowledges support by the Japanese Society for the Promotion of
Science (JSPS) KAKENHI (19204017). x. S. and M. O. acknowledge support
by the Polish Ministry of Education and Science (MEiN) grant
1-P03D-003-29. M. J. H. acknowledges support from the Royal Society and
J. L. G. thanks the UK Science and Technology Facilities Council for a
studentship. M. O. thanks Malgosia Mochol for her assistance in the
evaluation of the Chandra data. This research is funded in part by
National Aeronautics and Space Administration (NASA) contract
NAS8-39073. Partial support for this work was provided by the NASA
through Chandra Awards Number GO5-6113X and GO7-8103X-R issued by the
Chandra X-Ray Observatory Center, which is operated by the Smithsonian
Astrophysical Observatory for and on behalf of NASA under contract
NAS8-39073. This research has made use of data obtained by Chandra X-Ray
Observatory and software provided by the Chandra X-Ray Center (CXC).
This research has also made use of SAOImage DS9, developed by
Smithsonian Astrophysical Observatory. The National Radio Astronomy
Observatory is a facility of the National Science Foundation, operated
under cooperative agreement by Associated Universities, Inc.
NR 95
TC 21
Z9 21
U1 0
U2 3
PU IOP PUBLISHING LTD
PI BRISTOL
PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND
SN 0004-637X
EI 1538-4357
J9 ASTROPHYS J
JI Astrophys. J.
PD OCT 1
PY 2008
VL 685
IS 2
BP 839
EP 857
DI 10.1086/591024
PG 19
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 353FA
UT WOS:000259550300012
ER
PT J
AU Arendt, RG
Gezari, DY
Stolovy, SR
Sellgren, K
Smith, R
Ramirez, SV
Yusef-Zadeh, F
Law, CJ
Smith, HA
Cotera, AS
Moseley, SH
AF Arendt, R. G.
Gezari, D. Y.
Stolovy, S. R.
Sellgren, K.
Smith, R.
Ramirez, S. V.
Yusef-Zadeh, F.
Law, C. J.
Smith, H. A.
Cotera, A. S.
Moseley, S. H.
TI Comparison of 3.6-8.0 mu m Spitzer/IRAC Galactic Center Survey point
sources with Chandra X-ray point sources in the central 40x40 parsecs
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE Galaxy : center; infrared : stars; X-rays : binaries
ID CENTER REGION; STAR; POPULATION; CATALOG; EXTINCTION; EMISSION;
BINARIES; GALAXY
AB We have studied the correlation between 2357 Chandra X-ray point sources in a 40 x 40 pc field and similar to 20,000 infrared sources we observed in the corresponding subset of our 2 degrees x 1.4 degrees Spitzer/IRAC Galactic Center Survey at 3.6-8.0 mu m, using various spatial and X-ray hardness thresholds. The correlation was determined for source separations of less than 0.5 '', 1 '', or 2 ''. Only the soft X-ray sources show any correlation with infrared point sources on these scales, and that correlation is very weak. The upper limit on hard X-ray sources that have infrared counterparts is < 1.7% (3 sigma). However, because of the confusion limit of the IR catalog, we only detect IR sources with absolute magnitudes less than or similar to 1. As a result, a stronger correlation with fainter sources cannot be ruled out. Only one compact IR source, IRS 13, coincides with any of the dozen prominent X-ray emission features in the 3 x 3 pc region centered on Sgr A*, and the diffuse X-ray and IR emission around Sgr A* seems to be anticorrelated on a few-arcsecond scale. We compare our results with previous identifications of near-infrared companions to Chandra X-ray sources.
C1 [Arendt, R. G.; Moseley, S. H.] NASA, Goddard Space Flight Ctr, CRESST, UMBC,GSFC,Code 665, Greenbelt, MD 20771 USA.
[Gezari, D. Y.; Smith, R.; Moseley, S. H.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
[Stolovy, S. R.] CALTECH, Spitzer Sci Ctr, Pasadena, CA 91125 USA.
[Sellgren, K.] Ohio State Univ, Dept Astron, Columbus, OH 43210 USA.
[Ramirez, S. V.] CALTECH, IPAC, Pasadena, CA 91125 USA.
[Yusef-Zadeh, F.; Law, C. J.] Northwestern Univ, Dept Phys & Astron, Evanston, IL 60208 USA.
[Smith, H. A.] Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA.
[Cotera, A. S.] SETI Inst, Mountain View, CA 94043 USA.
RP Arendt, RG (reprint author), NASA, Goddard Space Flight Ctr, CRESST, UMBC,GSFC,Code 665, 8800 Greenbelt Rd, Greenbelt, MD 20771 USA.
EM richard.g.arendt@nasa.gov
RI Moseley, Harvey/D-5069-2012
FU NASA; JPL's Long Wavelength Center; Spitzer Science Center
FX This work is based on observations made with the Spitzer Space
Telescope, which is operated by the Jet Propulsion Laboratory,
California Institute of Technology, under a contract with NASA. Support
for this work was provided by NASA. K. S. thanks the NASA Faculty
Fellowship Program for financial support and the hospitality of JPL's
Long Wavelength Center and the Spitzer Science Center. We thank the
referee for substantial comments and suggestions.
NR 29
TC 4
Z9 4
U1 0
U2 3
PU IOP PUBLISHING LTD
PI BRISTOL
PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD OCT 1
PY 2008
VL 685
IS 2
BP 958
EP 970
DI 10.1086/591015
PG 13
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 353FA
UT WOS:000259550300022
ER
PT J
AU Dwek, E
Arendt, RG
AF Dwek, Eli
Arendt, Richard G.
TI Infrared echoes reveal the shock breakout of the Cas A supernova
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE dust, extinction; infrared : ISM; ISM : individual (Cas A); shock waves;
supernovae : general; supernova remnants
ID LARGE-MAGELLANIC-CLOUD; REMNANT CASSIOPEIA-A; ULTRAVIOLET
EMISSION-LINES; GIANT MOLECULAR CLOUDS; INTERSTELLAR-MEDIUM; LIGHT
ECHOES; SN 1987A; SN-1987A; DUST; CONSTRAINTS
AB Through the serendipitous discovery of infrared echoes around the CasA supernova remnant, the Spitzer satellite has provided astronomers with a unique opportunity to study the properties of the echoing material and the history and nature of the outburst that generated these echoes. In retrospect, we find that the echoes are also clearly visible as infrared ''hot spots'' in IRAS images of the region. The spectra of the echoes are distinct from that of the dust in the general diffuse interstellar medium (ISM), revealing hot silicate grains that are either stochastically heated to temperatures in excess of similar to 150 K or radiating at an equilibrium temperature of this value. We show that the maximum luminosity that can be generated by the radioactive decay of (56)Ni is not capable of producing such spectra, and could therefore not have given rise to the echoes. Instead, we find that the echoes must have been generated by an intense and short burst of EUV-UV radiation associated with the breakout of the shock through the surface of the exploding star. The inferred luminosity of the burst depends on the amount of attenuation in the intervening medium to the clouds, and we derive a burst luminosity of similar to 1.5 x 10(11) L(circle dot) for an assumed H-column density of 1.5 x 10(19) cm(-2). The average H-column density of the IR-emitting region in the echoing clouds is about 5 x 10(17) cm(-2). Derivation of their density requires knowledge of the width of the echo that is sweeping through the ISM, which in turn is determined by the duration of the burst. A burst time of similar to 1 day gives a cloud density of similar to 400 cm(-3), typical of dense IR cirrus.
C1 [Dwek, Eli] NASA, Goddard Space Flight Ctr, Observat Cosmol Lab, Code 665, Greenbelt, MD 20771 USA.
[Arendt, Richard G.] Univ Maryland Baltimore Cty, NASA, Goddard Space Flight Ctr, Code 665, Greenbelt, MD 20771 USA.
RP Dwek, E (reprint author), NASA, Goddard Space Flight Ctr, Observat Cosmol Lab, Code 665, Greenbelt, MD 20771 USA.
EM eli.dwek@nasa.gov; richard.g.arendt@nasa.gov
RI Dwek, Eli/C-3995-2012;
OI Arendt, Richard/0000-0001-8403-8548
FU NASA's [LTSA03-0000-065]
FX E. D. acknowledges the support of NASA's LTSA03-0000-065. We thank the
referee for his/her critical comments. This work is based on
observations made with the Spitzer Space Telescope, which is operated by
the Jet Propulsion Laboratory, California Institute of Technology, under
contract with NASA.
NR 33
TC 25
Z9 25
U1 0
U2 2
PU IOP PUBLISHING LTD
PI BRISTOL
PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD OCT 1
PY 2008
VL 685
IS 2
BP 976
EP 987
DI 10.1086/589988
PG 12
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 353FA
UT WOS:000259550300024
ER
PT J
AU Tanaka, T
Uchiyama, Y
Aharonian, FA
Takahashi, T
Bamba, A
Hiraga, JS
Kataoka, J
Kishishita, T
Kokubun, M
Mori, K
Nakazawa, K
Petre, R
Tajima, H
Watanabe, S
AF Tanaka, Takaaki
Uchiyama, Yasunobu
Aharonian, Felix A.
Takahashi, Tadayuki
Bamba, Aya
Hiraga, Junko S.
Kataoka, Jun
Kishishita, Tetsuichi
Kokubun, Motohide
Mori, Koji
Nakazawa, Kazuhiro
Petre, Robert
Tajima, Hiroyasu
Watanabe, Shin
TI Study of nonthermal emission from SNR RX J1713.7-3946 with Suzaku
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE acceleration of particles; ISM : individual (RX J1713.7-3946); supernova
remnants; X-rays : ISM
ID SUPERNOVA-REMNANT G347.3-0.5; X-RAY-EMISSION; MONTE-CARLO SIMULATOR;
PARTICLE-ACCELERATION; BOARD SUZAKU; COSMIC-RAYS; MOLECULAR CLOUDS;
DETECTOR HXD; SHOCK-WAVES; XMM-NEWTON
AB We present results obtained from a series of observations of the supernova remnant RX J1713.7-3946 by Suzaku. Hard X-rays have been detected up to similar to 40 keV. The hard X-ray spectra are described by a power law with photon indices of similar to 3.0, which is larger than those below 10 keV. The combination of the spatially integrated XIS and HXD spectra clearly reveals a spectral cutoff which is linked to the maximum energy of accelerated electrons. The broad-band coverage of Suzaku allows us to derive, for the first time, the energy spectrum of parent electrons in the cutoff region. The cutoff energy in the X-ray spectrum indicates that the electron acceleration in the remnant proceeds close to the Bohm diffusion limit. We discuss the implications of the spectral and morphological properties of the Suzaku data in the context of the origin of nonthermal emission. The Suzaku X-ray and H.E.S.S. gamma-ray data together hardly can be explained within a pure leptonic scenario. Moreover, the leptonic models require a weak magnetic field, which is inconsistent with the recently discovered X-ray filamentary structures and their short-term variability. The hadronic models with strong magnetic fields provide reasonable fits to the observed spectra, but require special arrangements of parameters to explain the lack of thermal X-ray emission. For morphology studies, we compare the X-ray and TeV gamma-ray surface brightness. We confirm the previously reported strong correlation between X-rays and TeV gamma rays. At the same time, the Suzaku data reveal a deviation from the general tendency, namely, the X-ray emission in the western rims appears brighter than expected from the average X-ray to gamma-ray ratio.
C1 [Tanaka, Takaaki; Uchiyama, Yasunobu; Takahashi, Tadayuki; Bamba, Aya; Kishishita, Tetsuichi; Kokubun, Motohide; Watanabe, Shin] Japan Aerosp Explorat Agcy, Inst Space & Astronaut Sci, Dept High Energy Astrophys, Sagamihara, Kanagawa 2298510, Japan.
[Tanaka, Takaaki; Tajima, Hiroyasu] Stanford Linear Accelerator Ctr, Kavli Inst Particle Astrophys & Cosmol, Menlo Pk, CA 94025 USA.
[Aharonian, Felix A.] Dublin Inst Adv Studies, Dublin 2, Ireland.
[Aharonian, Felix A.] Max Planck Inst Kernphys, D-69029 Heidelberg, Germany.
[Takahashi, Tadayuki; Kishishita, Tetsuichi; Nakazawa, Kazuhiro] Univ Tokyo, Dept Phys, Bunkyo Ku, Tokyo 1130033, Japan.
[Hiraga, Junko S.] RIKEN, Cosm Radiat Lab, Wako, Saitama 3510198, Japan.
[Kataoka, Jun] Tokyo Inst Technol, Dept Phys, Meguro Ku, Tokyo 1528551, Japan.
[Mori, Koji] Miyazaki Univ, Dept Appl Phys, Miyazaki 8892192, Japan.
[Petre, Robert] NASA, Goddard Space Flight Ctr, Xray Astrophys Lab, Greenbelt, MD 20771 USA.
RP Tanaka, T (reprint author), Japan Aerosp Explorat Agcy, Inst Space & Astronaut Sci, Dept High Energy Astrophys, 3-1-1 Yoshinodai, Sagamihara, Kanagawa 2298510, Japan.
RI XRAY, SUZAKU/A-1808-2009
FU Japan Society for the Promotion of Science for Young Scientists
FX The authors would like to thank all the members of the Suzaku Science
Working Group for their help in the spacecraft operation, instrumental
calibration, and data processing. The authors thank Una Hwang for
carefully reading the manuscript and Stefan Funk for assisting with the
comparison of the morphologies with the H.E.S.S. data and for his
helpful comments on the manuscript. The authors also thank Misha Malkov
and Vladimir Zirakashvili for discussions related to different aspects
of the diffusive shock acceleration theory. T. Tanaka and A. Bamba are
supported by research fellowships of the Japan Society for the Promotion
of Science for Young Scientists.
NR 52
TC 77
Z9 77
U1 0
U2 3
PU IOP PUBLISHING LTD
PI BRISTOL
PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD OCT 1
PY 2008
VL 685
IS 2
BP 988
EP 1004
DI 10.1086/591020
PG 17
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 353FA
UT WOS:000259550300025
ER
PT J
AU Israel, GL
Romano, P
Mangano, V
Dall'Osso, S
Chincarini, G
Stella, L
Campana, S
Belloni, T
Tagliaferri, G
Blustin, AJ
Sakamoto, T
Hurley, K
Zane, S
Moretti, A
Palmer, D
Guidorzi, C
Burrows, DN
Gehrels, N
Krimm, HA
AF Israel, G. L.
Romano, P.
Mangano, V.
Dall'Osso, S.
Chincarini, G.
Stella, L.
Campana, S.
Belloni, T.
Tagliaferri, G.
Blustin, A. J.
Sakamoto, T.
Hurley, K.
Zane, S.
Moretti, A.
Palmer, D.
Guidorzi, C.
Burrows, D. N.
Gehrels, N.
Krimm, H. A.
TI A Swift gaze into the 2006 March 29 burst forest of SGR 1900+14
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE pulsars : individual (SGR 1900+14); stars : flare; stars : neutron;
X-rays : bursts
ID SOFT GAMMA-REPEATERS; MAGNETIZED NEUTRON-STARS; X-RAY-EMISSION; SGR
1900+14; GIANT FLARE; RADIATIVE MECHANISM; DISCOVERY; SGR-1806-20;
TELESCOPE; PERSISTENT
AB In 2006 March the soft gamma-ray repeater SGR 1900+14 resumed its bursting activity after similar to 2 yr of quiescence. The Swift mission observed the source several times. We report on the intense burst "forest'' recorded on March 29, which lasted for similar to 30 s, when Swift was pointing at the source with the narrow field of view instruments. More than 40 bursts were detected by BAT and XRT, 7 of which were rare intermediate flares (IFs). The BAT data were used to carry out time-resolved spectroscopy in the 14-100 keV range down to 8 ms timescales. BAT and XRT simultaneous data were used to characterize the broadband energy spectra of IFs and verify the results obtained from the BAT-only spectral fits. This unique data set allowed us to test the magnetar model predictions, such as the magnetically trapped fireball and twisted magnetosphere, over an unprecedented range of fluxes and with large statistics. We confirmed that a two-blackbody component adequately fits the time-resolved and integrated spectra of IFs. However, Comptonization models give comparably good reduced chi(2). Moreover, we found a change of behavior, around similar to 10(41) erg s(-1), above which the softer blackbody shows a sort of saturation, while the harder one still grows to a few times 10(41) erg s(-1), and a rather sharp correlation between temperature and radii of the blackbodies (R-2 proportional to kT(-3)), which holds for the most luminous parts of the flares (similar to L-tot >= 10(41) erg s(-1)). Within the magnetar model, the majority of these findings are accounted for in terms of thermalized emission from the E-mode and O-mode photospheres. Interestingly, the maximum observed luminosity coming from a region of similar to 15 km matches the magnetic Eddington luminosity at the same radius, for a surface dipole field of similar to 8 x 10(14) G (virtually equal to that deduced from the spin-down of SGR 1900+14).
C1 [Israel, G. L.; Dall'Osso, S.; Stella, L.] INAF Osservatorio Astron Roma, I-00040 Monte Porzio Catone, Roma, Italy.
[Romano, P.; Chincarini, G.; Campana, S.; Belloni, T.; Tagliaferri, G.; Moretti, A.; Guidorzi, C.] INAF Osservatorio Astron Brera, I-23807 Merate, Italy.
[Romano, P.; Chincarini, G.; Guidorzi, C.] Univ Milan, I-20126 Milan, Italy.
[Romano, P.; Mangano, V.] INAF Ist Astrofis Spaziale & Fis Cosmica Sezione, I-90146 Palermo, Italy.
[Dall'Osso, S.] Univ Pisa, Dipartmento Fis Enrico Fermi, I-56127 Pisa, Italy.
[Blustin, A. J.; Zane, S.] UCL, Mullard Space Sci Lab, Dorking RH5 6NT, Surrey, England.
[Sakamoto, T.; Gehrels, N.; Krimm, H. A.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
[Hurley, K.] Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA.
[Palmer, D.] Los Alamos Natl Lab, Los Alamos, NM 87545 USA.
[Burrows, D. N.] Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA.
[Krimm, H. A.] Univ Space Res Assoc, Columbia, MD 21044 USA.
RP Israel, GL (reprint author), INAF Osservatorio Astron Roma, Via Frascati 33, I-00040 Monte Porzio Catone, Roma, Italy.
EM gianluca@mporzio.astro.it; stella@mporzio.astro.it
RI Gehrels, Neil/D-2971-2012;
OI moretti, alberto/0000-0002-9770-0315; Israel,
GianLuca/0000-0001-5480-6438; Tagliaferri, Gianpiero/0000-0003-0121-0723
FU Agenzia Spazialc Italiana (ASI) [I/011/07/0, I/088/06/0]; Ministero
dell'Istruzione; Universita e Ricerca Scientifica e Tecnologica
(MIUR-COFIN); Istituto Nazionale di Astrofisica (INAF); MIUR
[2005025417]
FX This work is partially supported at OAR through Agenzia Spazialc
Italiana (ASI), Ministero dell'Istruzione, Universita e Ricerca
Scientifica e Tecnologica (MIUR-COFIN), and Istituto Nazionale di
Astrofisica (INAF) grants. This work is supported at OAB and OAR by ASI
grants I/011/07/0 and I/088/06/0 and at OAB by MIUR PRIN 2005025417. We
gratefully acknowledge the contributions of dozens of members of the
BAT, XRT, and UVOT Teams at OAB, PSU, UL, GSFC, ASDC, and MSSL and their
subcontractors, who helped make the Swift mission possible. G. L. I.
would like to thank Alaa Ibrahim for useful discussions on the
comparison between the burst spectral properties of SGR 1806-20 and SGR
1900+14, Marco Feroci for comparison with burst properties of SGR
1900+14 as observed by BeppoSAX, and Peter Woods for careful reading of
the manuscript and valuable suggestions for its improvement.
NR 53
TC 50
Z9 50
U1 0
U2 3
PU IOP PUBLISHING LTD
PI BRISTOL
PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND
SN 0004-637X
EI 1538-4357
J9 ASTROPHYS J
JI Astrophys. J.
PD OCT 1
PY 2008
VL 685
IS 2
BP 1114
EP 1128
DI 10.1086/590486
PG 15
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 353FA
UT WOS:000259550300037
ER
PT J
AU Brown, TM
Beaton, R
Chiba, M
Ferguson, HC
Gilbert, KM
Guhathakurta, P
Iye, M
Kalirai, JS
Koch, A
Komiyama, Y
Majewski, SR
Reitzel, DB
Renzini, A
Rich, RM
Smith, E
Sweigart, AV
Tanaka, M
AF Brown, Thomas M.
Beaton, Rachael
Chiba, Masashi
Ferguson, Henry C.
Gilbert, Karoline M.
Guhathakurta, Puragra
Iye, Masanori
Kalirai, Jasonjot S.
Koch, Andreas
Komiyama, Yutaka
Majewski, Steven R.
Reitzel, David B.
Renzini, Alvio
Rich, R. Michael
Smith, Ed
Sweigart, Allen V.
Tanaka, Mikito
TI THE EXTENDED STAR FORMATION HISTORY OF THE ANDROMEDA SPHEROID AT 35 kpc
ON THE MINOR AXIS
SO ASTROPHYSICAL JOURNAL LETTERS
LA English
DT Article
DE galaxies: evolution; galaxies: halos; galaxies: individual (M31);
galaxies: stellar content
ID GIANT SOUTHERN STREAM; STELLAR POPULATION; GALAXY FORMATION; OUTER DISK;
M31; HALO; PHOTOMETRY; SUBSTRUCTURE; METALLICITY; LUMINOSITY
AB Using the HST ACS, we have obtained deep optical images reaching well below the oldest main-sequence turnoff in fields on the southeast minor axis of the Andromeda galaxy, 35 kpc from the nucleus. These data probe the star formation history in the extended halo of Andromeda-that region beyond 30 kpc that appears both chemically and morphologically distinct from the metal-rich, highly disturbed inner spheroid. The present data, together with our previous data for fields at 11 and 21 kpc, do not show a simple trend toward older ages and lower metallicities, as one might expect for populations further removed from the obvious disturbances of the inner spheroid. Specifically, at 11, 21, and 35 kpc, the mean ages are 9.7, 11.0, and 10.5 Gyr, respectively, and the mean [Fe/H] values are -0.65, -0.87, and -0.98, respectively. In the best-fit model of the 35 kpc population, one-third of the stars are younger than 10 Gyr, whereas only similar to 10% of the stars are truly ancient and metal-poor. The extended halo thus exhibits clear evidence of its hierarchical assembly, and the contribution from any classical halo formed via early monolithic collapse must be small.
C1 [Brown, Thomas M.; Ferguson, Henry C.; Smith, Ed] Space Telescope Sci Inst, Baltimore, MD 21218 USA.
[Beaton, Rachael; Majewski, Steven R.] Univ Virginia, Dept Astron, Charlottesville, VA 22904 USA.
[Chiba, Masashi] Tohoku Univ, Astron Inst, Sendai, Miyagi 9808578, Japan.
[Gilbert, Karoline M.; Guhathakurta, Puragra; Kalirai, Jasonjot S.] Univ Calif Santa Cruz, Univ Calif Observ, Lick Observ, Santa Cruz, CA 95064 USA.
[Komiyama, Yutaka] Natl Astron Observ, Tokyo 1818588, Japan.
[Koch, Andreas; Reitzel, David B.; Rich, R. Michael] Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA.
[Renzini, Alvio] Osserv Astron Padova, I-35122 Padua, Italy.
[Sweigart, Allen V.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
RP Brown, TM (reprint author), Space Telescope Sci Inst, 3700 San Martin Dr, Baltimore, MD 21218 USA.
EM tbrown@stsci.edu; rlb9n@virginia.edu; chiba@astr.tohoku.ac.jp;
ferguson@stsci.edu; kgilbert@ucolick.org; raja@ucolick.org;
m.iye@nao.ac.jp; jkalirai@ucolick.org; akoch@astro.ucla.edu;
komiyama@subaru.naoj.org; srm4n@virginia.edu; reitzel@ucla.astro.edu;
alvio.renzini@oapd.inaf.it; rmr@astro.ucla.edu; edsmith@stsci.edu;
allen.v.sweigart@nasa.gov; mikito.tanaka@nao.ac.jp
OI Koch, Andreas/0000-0002-9859-4956; Beaton, Rachael/0000-0002-1691-8217
FU NASA [GO-10265, GO-10816, HF-01185.01-A]; AURA, Inc. [NAS 5-26555]; NSF
[AST0307966, AST-0507483, AST-0307931, AST0307842, AST-0607726]
FX Support for GO-10816 is provided by NASA through a grant from STScI,
which is operated by AURA, Inc., under contract NAS 5-26555. We
acknowledge support from NSF grants AST0307966/AST-0507483 ( P. G.),
AST-0307931 (R. M. R.), AST0307842/AST-0607726 (S. R. M., R. B.),
NASA/STScI grants GO-10265/GO-10816 (P. G., R. M. R.), and NASA Hubble
Fellowship grant HF-01185.01-A (J. S. K.). We are grateful to P. Stetson
for his DAOPHOT code and to J. Harris for his Starfish code.
NR 26
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PU IOP PUBLISHING LTD
PI BRISTOL
PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND
J9 ASTROPHYS J LETT
JI Astrophys. J. Lett.
PD OCT 1
PY 2008
VL 685
IS 2
BP L121
EP L124
DI 10.1086/592686
PG 4
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 398PW
UT WOS:000262745000006
ER
PT J
AU Zhang, ZW
Bianco, FB
Lehner, MJ
Coehlo, NK
Wang, JH
Mondal, S
Alcock, C
Axelrod, T
Byun, YI
Chen, WP
Cook, KH
Dave, R
de Pater, I
Porrata, R
Kim, DW
King, SK
Lee, T
Lin, HC
Lissauer, JJ
Marshall, SL
Protopapas, P
Rice, JA
Schwamb, ME
Wang, SY
Wen, CY
AF Zhang, Z. -W.
Bianco, F. B.
Lehner, M. J.
Coehlo, N. K.
Wang, J. -H.
Mondal, S.
Alcock, C.
Axelrod, T.
Byun, Y. -I.
Chen, W. P.
Cook, K. H.
Dave, R.
de Pater, I.
Porrata, R.
Kim, D. -W.
King, S. -K.
Lee, T.
Lin, H. -C.
Lissauer, J. J.
Marshall, S. L.
Protopapas, P.
Rice, J. A.
Schwamb, M. E.
Wang, S. -Y.
Wen, C. -Y.
TI FIRST RESULTS FROM THE TAIWANESE-AMERICAN OCCULTATION SURVEY (TAOS)
SO ASTROPHYSICAL JOURNAL LETTERS
LA English
DT Article
DE Kuiper Belt; occultations; solar system: formation
ID KUIPER-BELT OBJECTS; STELLAR OCCULTATIONS; SIZE DISTRIBUTION;
MILLISECOND DIPS; SOLAR-SYSTEM; ACCRETION; BODIES; SEARCH; X-1
AB Results from the first 2 years of data from the Taiwanese-American Occultation Survey (TAOS) are presented. Stars have been monitored photometrically at 4 or 5 Hz to search for occultations by small (similar to 3 km) Kuiper Belt objects (KBOs). No statistically significant events were found, allowing us to present an upper bound to the size distribution of KBOs with diameters 0.5 km < D < 28 km.
C1 [Zhang, Z. -W.; Wang, J. -H.; Mondal, S.; Chen, W. P.; Lin, H. -C.] Natl Cent Univ, Inst Astron, Jhongli 320, Taoyuan County, Taiwan.
[Bianco, F. B.] Univ Penn, Dept Phys & Astron, Philadelphia, PA 19104 USA.
[Bianco, F. B.; Lehner, M. J.; Alcock, C.; Protopapas, P.] Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA.
[Lehner, M. J.; Wang, J. -H.; King, S. -K.; Lee, T.; Wang, S. -Y.; Wen, C. -Y.] Acad Sinica, Inst Astron & Astrophys, Taipei 106, Taiwan.
[Coehlo, N. K.; Rice, J. A.] Univ Calif Berkeley, Dept Stat, Berkeley, CA 94720 USA.
[Axelrod, T.] Univ Arizona, Steward Observ, Tucson, AZ 85721 USA.
[Byun, Y. -I.; Kim, D. -W.] Yonsei Univ, Dept Astron, Seoul 120749, South Korea.
[Cook, K. H.; Marshall, S. L.] Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Livermore, CA 94550 USA.
[Dave, R.] Harvard Univ, Initiat Innovat Comp, Cambridge, MA 02138 USA.
[de Pater, I.; Porrata, R.] Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA.
[Lissauer, J. J.] NASA, Ames Res Ctr, Space Sci & Astrobiol Div 245 3, Moffett Field, CA 94035 USA.
[Marshall, S. L.] Kavli Inst Particle Astrophys & Cosmol, Menlo Pk, CA 94025 USA.
[Schwamb, M. E.] CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA.
RP Zhang, ZW (reprint author), Natl Cent Univ, Inst Astron, 300 Jhongda Rd, Jhongli 320, Taoyuan County, Taiwan.
EM s1249001@cc.ncu.edu.tw
RI Lee, Typhoon/N-8347-2013;
OI Lehner, Matthew/0000-0003-4077-0985; Schwamb, Megan/0000-0003-4365-1455
FU NSC [96-2112-M008-024-MY3]; NSF [AST 05-01681, DMS-0405777]; NASA
[NNG04G113G, NASA/PGG]; thematic research program [AS-88-TP-A02]; KRCF;
US DOE [W-7405-Eng-48, DE-AC52-07NA27344, DE-AC02-76SF00515]
FX Work at NCU was supported by the grant NSC 96-2112-M008-024-MY3. Work at
the CfA was supported in part by the NSF under grant AST 05-01681 and by
NASA under grant NNG04G113G. Work at ASIAA was supported in part by the
thematic research program AS-88-TP-A02. Work at UCB was supported by the
NSF under grant DMS-0405777. Work at Yonsei was supported by the KRCF
grant to Korea Astronomy and Space Science Institute. Work at LLNL was
performed under the auspices of the US DOE in part under contract
W-7405-Eng-48 and contract DE-AC52-07NA27344. Work at SLAC was performed
under US DOE contract DE-AC02-76SF00515. Work at NASA Ames was funded by
NASA/PG&G.
NR 26
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U1 0
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PU IOP PUBLISHING LTD
PI BRISTOL
PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND
J9 ASTROPHYS J LETT
JI Astrophys. J. Lett.
PD OCT 1
PY 2008
VL 685
IS 2
BP L157
EP L160
DI 10.1086/592741
PG 4
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 398PW
UT WOS:000262745000015
ER
PT J
AU Zsargo, J
Hillier, DJ
Bouret, JC
Lanz, T
Leutenegger, MA
Cohen, DH
AF Zsargo, J.
Hillier, D. J.
Bouret, J. -C.
Lanz, T.
Leutenegger, M. A.
Cohen, D. H.
TI ON THE IMPORTANCE OF THE INTERCLUMP MEDIUM FOR SUPERIONIZATION: O VI
FORMATION IN THE WIND OF zeta PUPPIS
SO ASTROPHYSICAL JOURNAL LETTERS
LA English
DT Article
DE stars: early-type; stars: winds, outflows; X-rays: individual (zeta
Puppis); X-rays: stars
ID X-RAY-EMISSION; RADIATION-DRIVEN WINDS; HOT-STAR WINDS; STELLAR WINDS;
LINE-PROFILES; COPERNICUS-SATELLITE; MAGELLANIC-CLOUD; IONIZATION;
SPECTRUM; INSTABILITIES
AB We have studied superionization and X-ray line formation in the spectra of zeta Pup using our new stellar atmosphere code (XCMFGEN) that can be used to simultaneously analyze optical, UV, and X-ray observations. Here, we present results on the formation of the O VI lambda lambda 1032, 1038 doublet. Our simulations, supported by simple theoretical calculations, show that clumped wind models that assume void in the interclump space cannot reproduce the observed O vi profiles. However, enough O vi can be produced if the voids are filled by a low-density gas. The recombination of O vi is very efficient in the dense material, but in the tenuous interclump region an observable amount of O vi can be maintained. We also find that different UV resonance lines are sensitive to different density regimes in z Pup: C IV is almost exclusively formed within the densest regions, while the majority of O vi resides between clumps. N v is an intermediate case, with contributions from both the tenuous gas and clumps.
C1 [Zsargo, J.; Hillier, D. J.] Univ Pittsburgh, Dept Phys & Astron, Pittsburgh, PA 15260 USA.
[Bouret, J. -C.] Univ Aix Marseille 1, CNRS, Lab Astrophys Marseille, F-13388 Marseille 13, France.
[Lanz, T.] Univ Maryland, Dept Astron, College Pk, MD 20742 USA.
[Leutenegger, M. A.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
[Cohen, D. H.] Swarthmore Coll, Dept Phys & Astron, Swarthmore, PA 19081 USA.
RP Zsargo, J (reprint author), Univ Pittsburgh, Dept Phys & Astron, 3941 OHara St, Pittsburgh, PA 15260 USA.
EM jaz8@pitt.edu
FU STScI [HST-AR-10693.02]; SAO [TM6-7003X]; French National Research
Agency (ANR) [ANR-06-BLAN-0105]; Chandra X-Ray Center at SAO [AR7-8002X]
FX This research was supported by STScI grant HST-AR-10693.02 and by SAO
grant TM6-7003X. We are also grateful to Randall Smith for providing us
the source code of APEC and to the Chandra X-Ray Center for the use of
ATOMDB. Maurice A. Leutenegger acknowledges support from a fellowship
administered by Oak Ridge Associated Universities under the NASA
Postdoctoral Program. J.-C. Bouret acknowledges financial support from
the French National Research Agency (ANR) through program
ANR-06-BLAN-0105. David Cohen acknowledges support from grant AR7-8002X
from the Chandra X-Ray Center at SAO.
NR 34
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PU IOP PUBLISHING LTD
PI BRISTOL
PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND
J9 ASTROPHYS J LETT
JI Astrophys. J. Lett.
PD OCT 1
PY 2008
VL 685
IS 2
BP L149
EP L152
DI 10.1086/592568
PG 4
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 398PW
UT WOS:000262745000013
ER
PT J
AU Lin, JL
Han, WQ
Lin, X
AF Lin, Jia-Lin
Han, Weiqing
Lin, Xin
TI Observational analysis of the wind-evaporation-SST feedback over the
tropical Pacific Ocean
SO ATMOSPHERIC SCIENCE LETTERS
LA English
DT Article
DE tropical climate; ITCZ; ocean-atmosphere feedback
ID LATITUDINAL ASYMMETRY; ATMOSPHERE MODEL; ITCZ; CLOUDS; HEAT;
CIRCULATION; DYNAMICS; MONSOON; PROJECT; NORTH
AB Theoretical studies suggested that the wind-evaporation-sea surface temperature (SST) (WES) feedback plays an important role in maintaining the latitudinal asymmetry of the intertropical convergence zone (ITCZ) in the tropical Pacific Ocean. This study examines the geographical distribution of the strength of WES feedback over the tropical Pacific Ocean using multiple long-term observational datasets. The results show that the WES feedback is very weak over the eastern Pacific warm pool and stratocumulus regions, where the strongest latitudinal asymmetry of the ITCZ exists, suggesting that some other mechanisms are responsible for the asymmetry. To the west of 120W, the WES feedback has larger magnitude but is often statistically insignificant. This is because the effect of the air-sea humidity difference tends to offset the wind effect, which is a factor not considered in the original WES feedback theory. Copyright (c) 2008 Royal Meteorological Society
C1 [Lin, Jia-Lin] Ohio State Univ, Dept Geog, Columbus, OH 43210 USA.
[Han, Weiqing] Univ Colorado, Dept Atmospher & Ocean Sci, Boulder, CO 80309 USA.
[Lin, Xin] NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Greenbelt, MD 20771 USA.
RP Lin, JL (reprint author), Ohio State Univ, Dept Geog, 1105 Derby Hall,154 N Oval Mall, Columbus, OH 43210 USA.
EM lin.789@osu.edu
FU NASA Modeling, Analysis and Prediction ( MAP) Program; NSF grant
[ATM-0745872, OCE-0452917]; NASA Ocean Vector Wind Science Team Award
[1283568]
FX Jialin was supported by the NASA Modeling, Analysis and Prediction (
MAP) Program and NSF grant ATM-0745872. Weiqing Han was supported by NSF
OCE-0452917 and NASA Ocean Vector Wind Science Team Award 1283568. The
authors thank Chris Jones and two anonymous reviewers for their valuable
comments which significantly improved the manuscript.
NR 31
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U1 0
U2 4
PU WILEY-BLACKWELL
PI HOBOKEN
PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA
SN 1530-261X
J9 ATMOS SCI LETT
JI Atmos. Sci. Lett.
PD OCT-DEC
PY 2008
VL 9
IS 4
BP 231
EP 236
DI 10.1002/asl.195
PG 6
WC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences
SC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences
GA 414JX
UT WOS:000263860800011
ER
PT J
AU Smith, SM
Zwart, SR
AF Smith, Scott M.
Zwart, Sara R.
TI Calcium metabolism during space flight
SO CELL BIOLOGY AND TOXICOLOGY
LA English
DT Article; Proceedings Paper
CT European-Tissue-Culture-Society Workshop
CY APR 19, 2007
CL Univ Coll London, London, ENGLAND
SP European Tissue Culture Soc
HO Univ Coll London
ID INDUCED BONE LOSS; BED-REST; DISUSE OSTEOPOROSIS; HOMEOSTASIS;
WEIGHTLESSNESS; SPACEFLIGHT; MARKERS; COUNTERMEASURES; RESORPTION;
COSMONAUTS
C1 [Smith, Scott M.] NASA Johnson Space Ctr, Human Adaptat & Countermeasures Off, Nutr Biochem Lab, Houston, TX 77058 USA.
[Zwart, Sara R.] Univ Space Res Assoc, Houston, TX 77058 USA.
RP Smith, SM (reprint author), NASA Johnson Space Ctr, Human Adaptat & Countermeasures Off, Nutr Biochem Lab, Houston, TX 77058 USA.
EM scott.m.smith@nasa.gov
NR 46
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U1 1
U2 1
PU SPRINGER
PI DORDRECHT
PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS
SN 0742-2091
J9 CELL BIOL TOXICOL
JI Cell Biol. Toxicol.
PD OCT
PY 2008
VL 24
IS 5
BP 462
EP 466
PG 5
WC Cell Biology; Toxicology
SC Cell Biology; Toxicology
GA 340OF
UT WOS:000258654200017
ER
PT J
AU Ricca, A
Bauschlicher, CW
AF Ricca, Alessandra
Bauschlicher, Charles W., Jr.
TI The gas-phase catalytic formation of H(2) by cations
SO CHEMICAL PHYSICS LETTERS
LA English
DT Article
ID GAUSSIAN-BASIS SETS; HYDROGEN-ATOMS; CHEMISTRY; MOLECULE
AB We study the catalytic formation of H(2) by CH(3)(+) using high levels of theory. The first step involves the addition of an H atom to form CH(4)(+). The second H addition reaction yields CH(5)(+), which has the form CH(3)(+)-H(2). Both of these reactions are exothermic and have no reaction barriers. The final step is the loss of H(2), which has no barrier in excess of the reaction energy. Because the reaction of CH(4)(+)-H is significantly more exothermic than the loss of H(2) from CH(5)(+) is endothermic, the loss of H(2) will not be a bottleneck to the catalytic formation of H(2). (C) 2008 Elsevier B.V. All rights reserved.
C1 [Ricca, Alessandra] SETI Inst, Mountain View, CA 94043 USA.
[Bauschlicher, Charles W., Jr.] NASA, Ames Res Ctr, Space Technol Div, Moffett Field, CA 94035 USA.
RP Ricca, A (reprint author), SETI Inst, 515 N Whisman Rd, Mountain View, CA 94043 USA.
EM Alessandra.Ricca-1@nasa.gov
NR 28
TC 0
Z9 0
U1 0
U2 0
PU ELSEVIER SCIENCE BV
PI AMSTERDAM
PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS
SN 0009-2614
J9 CHEM PHYS LETT
JI Chem. Phys. Lett.
PD OCT 1
PY 2008
VL 463
IS 4-6
BP 327
EP 329
DI 10.1016/j.cplett.2008.08.069
PG 3
WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical
SC Chemistry; Physics
GA 351QM
UT WOS:000259439200007
ER
PT J
AU Giuliano, BM
Castrovilli, MC
Maris, A
Melandri, S
Caminati, W
Cohen, EA
AF Giuliano, Barbara M.
Castrovilli, Mattea C.
Maris, Assimo
Melandri, Sonia
Caminati, Walther
Cohen, Edward A.
TI A rotational study of the molecular complex tert-butanol center dot
center dot center dot NH(3)
SO CHEMICAL PHYSICS LETTERS
LA English
DT Article
ID TRANSFORM MICROWAVE SPECTROMETER; MILLIMETER-WAVE SPECTRUM;
MODEL-CALCULATIONS; WATER; CONSTANTS; DIMER; BEAM
AB The rotational spectra of tert-butanol center dot center dot center dot(14)NH(3) and tert-butanol center dot center dot center dot(15)NH(3) have been investigated and assigned by pulsed jet Fourier transform microwave spectroscopy. According to the values of the (14)N quadrupole coupling constants, the complex (where NH(3) acts as a proton acceptor) adopts a configuration with an almost linear O-H center dot center dot center dot N hydrogen bond. The NH(3) moiety undergoes a nearly free rotation. (C) 2008 Elsevier B.V. All rights reserved.
C1 [Giuliano, Barbara M.; Castrovilli, Mattea C.; Maris, Assimo; Melandri, Sonia; Caminati, Walther] Univ Bologna, Dipartimento Chim G Ciamician, I-40126 Bologna, Italy.
[Cohen, Edward A.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Caminati, W (reprint author), Univ Bologna, Dipartimento Chim G Ciamician, Via Selmi 2, I-40126 Bologna, Italy.
EM walther.caminati@unibo.it
RI Melandri, Sonia/D-9600-2014; Maris, Assimo/J-8141-2013; Castrovilli,
Mattea Carmen/K-6445-2016
OI Melandri, Sonia/0000-0002-0410-5833; Maris, Assimo/0000-0003-2644-0023;
Castrovilli, Mattea Carmen/0000-0002-7909-5115
NR 26
TC 15
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U1 1
U2 3
PU ELSEVIER SCIENCE BV
PI AMSTERDAM
PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS
SN 0009-2614
J9 CHEM PHYS LETT
JI Chem. Phys. Lett.
PD OCT 1
PY 2008
VL 463
IS 4-6
BP 330
EP 333
DI 10.1016/j.cplett.2008.08.071
PG 4
WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical
SC Chemistry; Physics
GA 351QM
UT WOS:000259439200008
ER
PT J
AU Toutanji, HA
Grugel, RN
AF Toutanji, Houssam A.
Grugel, Richard N.
TI Unconventional Approach
SO CIVIL ENGINEERING
LA English
DT Article
C1 [Toutanji, Houssam A.] Univ Alabama, Dept Civil & Environm Engn, Huntsville, AL 35899 USA.
[Grugel, Richard N.] NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA.
RP Toutanji, HA (reprint author), Univ Alabama, Dept Civil & Environm Engn, Huntsville, AL 35899 USA.
FU University of Alabama at Huntsville; National Aeronautics and Space
Administration's Marshall Space Flight Center, in Huntsville, Alabama;
Marshall Space Flight Center [NNM05AA22A]; "Mechanical Properties and
Durability Performance of 'Waterless Concrete',; Earth and Space 2008;
ASCE's Aerospace Division and held in Long Beach, California
FX Houssain A. Toutanji, F.ASCE, is a professor at the University of
Alabama at Huntsville and the chair of the civil and environmental
engineering department there. Richard N. Grugel, Ph.D., is a
metallurgical engineer at the National Aeronautics and Space
Administration's Marshall Space Flight Center, in Huntsville, Alabama.
The authors are greatful to the Marshall Space Flight Center for its
support of this work and for the financial support provided by grant
NNM05AA22A. They would also like to thank Edwin Ethridge, Ph.D., and 9
Dennis Tucker, Ph.D., both of whom are with the center, for providing
the glass fibers. This article is based on the authors' paper
"Mechanical Properties and Durability Performance of 'Waterless
Concrete'," which they presented at Earth and Space 2008, a conference
organized by ASCE's Aerospace Division and held in Long Beach,
California, in March.
NR 0
TC 0
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U1 0
U2 0
PU ASCE-AMER SOC CIVIL ENGINEERS
PI RESTON
PA 1801 ALEXANDER BELL DR, RESTON, VA 20191-4400 USA
SN 0885-7024
J9 CIVIL ENG
JI Civil Eng.
PD OCT
PY 2008
VL 78
IS 10
BP 70
EP 75
PG 6
WC Engineering, Civil
SC Engineering
GA 357WY
UT WOS:000259879100019
ER
PT J
AU Potter, C
Gross, P
Klooster, S
Fladeland, M
Genovese, V
AF Potter, Christopher
Gross, Peggy
Klooster, Steven
Fladeland, Matthew
Genovese, Vanessa
TI Storage of carbon in US forests predicted from satellite data, ecosystem
modeling, and inventory summaries
SO CLIMATIC CHANGE
LA English
DT Article
ID SPATIAL-PATTERNS; NORTH-AMERICA; BIOMASS; MODIS; PRODUCTIVITY;
LANDSCAPE; GROWTH; STATES
AB A plant and soil simulation model based on satellite observations of vegetation and climate data was used to estimate the potential carbon pools in standing wood biomass across all forest ecosystems of the conterminous United States up to the year 1997. These modeled estimates of vegetative carbon potential were compared to aggregated measurements of standing wood biomass from the U. S. Forest Service's national Forest Inventory and Analysis (FIA) data set and the Carbon Online Estimator (COLE) to understand: 1) predominant geographic variations in tree growth rate and 2) local land cover and land use history including the time since the last stand-replacing disturbance (e.g., from wildfire or harvest). Results suggest that although wood appears to be accumulating at high rates in many areas of the U.S. (Northwest and Southeast), there are still extensive areas of relatively low biomass forest in the late 1990s according to FIA records. We attribute these low biomass accumulation levels to the high frequency of disturbances, which can be observed even in high production areas such as the Southeast due to frequent forest harvests. Ecosystem models like the one presented in this study have been coupled with satellite observations of land cover and green plant density to uniquely differentiate areas with a high potential for vegetative carbon storage at relatively fine spatial resolution.
C1 [Potter, Christopher; Fladeland, Matthew] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
[Gross, Peggy; Klooster, Steven; Genovese, Vanessa] Calif State Univ Monterey Bay, Seattle, WA USA.
RP Potter, C (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
EM cpotter@mail.arc.nasa.gov
FU NASA; Earth Observing System (EOS) Interdisciplinary Science Program
FX This work was supported by grants from NASA program in Applied Earth
Science and the Earth Observing System (EOS) Interdisciplinary Science
Program. We gratefully acknowledge the contributions and assistance of
the USDA Forest Service North Central Research Station St.Paul, MN,
particularly B.Tyler Wilson and Patrick Miles in the use of FIA data
sets for this study.Results in this report are available online at
http://geo.arc.nasa.gov/sge/casa/, as part of the Carbon Query and
Evaluation Support Tools (CQUEST) project.
NR 35
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U1 1
U2 18
PU SPRINGER
PI DORDRECHT
PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS
SN 0165-0009
J9 CLIMATIC CHANGE
JI Clim. Change
PD OCT
PY 2008
VL 90
IS 3
BP 269
EP 282
DI 10.1007/s10584-008-9462-5
PG 14
WC Environmental Sciences; Meteorology & Atmospheric Sciences
SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences
GA 348BU
UT WOS:000259186800004
ER
PT J
AU Kaur, I
Simons, ER
Kapadia, AS
Ott, CM
Pierson, DL
AF Kaur, Indreshpal
Simons, Elizabeth R.
Kapadia, Asha S.
Ott, C. Mark
Pierson, Duane L.
TI Effect of spaceflight on ability of monocytes to respond to endotoxins
of gram-negative bacteria
SO CLINICAL AND VACCINE IMMUNOLOGY
LA English
DT Article
ID TOLL-LIKE RECEPTOR-4; SPACE-FLIGHT; SIGNAL-TRANSDUCTION; CYTOKINE
PRODUCTION; MISSION DURATION; LIPOPOLYSACCHARIDE; ASTRONAUTS;
RECOGNITION; LPS; EXPRESSION
AB Astronauts live and work in relatively crowded, confined environments on the Space Shuttle and the International Space Station. They experience a unique set of stressors that contribute to a diminishment of many immune responses. This study investigated the ability of the shuttle crew members' monocytes to respond to gram-negative endotoxin that they could encounter during infections. Blood specimens were collected from 20 crew members and 15 control subjects 10 days before launch, 3 to 4 h after landing, and 15 days after landing and from crew members during their annual medical examination at 6 to 12 months after landing. When challenged with gram-negative endotoxin, the crew member's monocytes collected at all three time points produced lower levels of interleukin-6 (IL-6) and IL-1 beta and higher levels of IL-1ra and IL-8 compared to those of control subjects. Cytokines were assessed by measuring the number of cells positive for intracellular cytokines. These values returned to normal 6 to 12 months after landing, except for IL-1ra, which was still higher (five- to sixfold) than in controls. This phenomenon was accompanied by an increased expression of Toll-like receptor 4 and decreased expression of CD14 on the crew members' monocytes at all time points. There were also increased levels of the lipopolysaccharide binding protein in the plasma of the crew members 3 to 4 h and 15 days after landing. This study shows that spaceflight-associated factors (in-flight and preflight) modulate the response of monocytes to gram-negative endotoxins.
C1 [Kaur, Indreshpal] Enterprise Advisory Serv Inc, Houston, TX USA.
[Simons, Elizabeth R.] Boston Univ, Sch Med, Dept Biochem, Boston, MA 02118 USA.
[Kapadia, Asha S.] Univ Texas Hlth Sci Ctr, Sch Publ Hlth, Houston, TX USA.
[Ott, C. Mark; Pierson, Duane L.] NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA.
RP Kaur, I (reprint author), Univ Texas MD Anderson Canc Ctr, Dept Stem Cell Transplantat & Cellular Therapy, Box 65,1515 Holcombe Blvd, Houston, TX 77030 USA.
EM ikaur@mdanderson.org
FU National Aeronautics and Space Administration [111-30-10-06]
FX We extend our appreciation to the astronauts and control subjects for
participating in this study.; We thank the National Aeronautics and
Space Administration for providing funding through NRA 111-30-10-06 to
conduct this work.
NR 45
TC 23
Z9 27
U1 0
U2 6
PU AMER SOC MICROBIOLOGY
PI WASHINGTON
PA 1752 N ST NW, WASHINGTON, DC 20036-2904 USA
SN 1556-6811
J9 CLIN VACCINE IMMUNOL
JI Clin. Vaccine Immunol.
PD OCT
PY 2008
VL 15
IS 10
BP 1523
EP 1528
DI 10.1128/CVI.00065-08
PG 6
WC Immunology; Infectious Diseases; Microbiology
SC Immunology; Infectious Diseases; Microbiology
GA 357BQ
UT WOS:000259821700005
PM 18768671
ER
PT J
AU Takahashi, F
Linteris, GT
Katta, VR
AF Takahashi, Fumiaki
Linteris, Gregory T.
Katta, Viswanath R.
TI Extinguishment of methane diffusion flames by carbon dioxide in coflow
air and oxygen-enriched microgravity environments
SO COMBUSTION AND FLAME
LA English
DT Article
DE Diffusion flame stabilization; Spacecraft fire suppression; Carbon
dioxide; Reaction kernel; Microgravity
ID REACTION KERNEL STRUCTURE; CUP-BURNER FLAMES; STABILIZATION; EXTINCTION;
MECHANISMS; LIMIT; FUEL
AB Microgravity experiments and computations have been conducted to elucidate stabilization and extinguishment mechanisms of methane diffusion flames, in the cup-burner configuration, with CO2 added gradually to a coflowing air or oxygen-enriched stream. The minimum extinguishing concentration of CO2 under low oxidizer velocities (<20 crn/s) was measured in microgravity achieved by parabolic flights of the NASA Reduced Gravity Aircraft. Transient computations with full chemistry and a gray-gas radiation model were performed to reveal the detailed flame structure and extinguishment processes. To compensate for the overestimation of radiative heat losses at high concentrations of radiating CO2, the Planck mean absorption coefficient was Multiplied by a correction factor (0 <= C <= 1). The fuel-lean peak reactivity spot (the so-called reaction kernel) at the flame base stabilized the trailing diffusion flame. The calculated temperature along the trailing flame decreased downstream due to radiative cooling, leading to local extinction at < 1300 K and flame tip opening. As CO2 was added to the oxidizer: (1) the calculated maximum flame temperature decreased toward a threshold (approximate to 1600 K); (2) the reaction kernel weakened (i.e., lower heat release rate) but nonetheless remained at a nearly constant temperature (approximate to 1450 K); (3) the flame base stabilized increasingly higher above the burner rim, parallel to the axis; until finally, (4) blowoff-type extinguishment occurred. In the lifted flame, the broadened reaction kernel supported a super-lean reaction branch on the oxidizer side as well as the trailing diffusion flame on the fuel-rich side (no triple flame structure was formed). (c) 2008 The Combustion Institute. Published by Elsevier Inc. All rights reserved.
C1 [Takahashi, Fumiaki] NASA, Glenn Res Ctr, Natl Ctr Space Explorat Res Fluids & Combust, Cleveland, OH 44135 USA.
[Linteris, Gregory T.] Natl Inst Stand & Technol, Fire Res Div, Gaithersburg, MD 20899 USA.
[Katta, Viswanath R.] Innovat Sci Solut Inc, Dayton, OH 45440 USA.
RP Takahashi, F (reprint author), NASA, Glenn Res Ctr, Natl Ctr Space Explorat Res Fluids & Combust, 21000 Brookpk Rd, Cleveland, OH 44135 USA.
EM fxt13@case.edu
FU Office of Biological and Physical Research; Fire Prevention, Detection,
and Suppression Program in the Exploration Technology Development
Program Office; National Aeronautics and Space Agency, Washington
FX This research was supported by the Office of Biological and Physical
Research and the Fire Prevention, Detection, and Suppression Program in
the Exploration Technology Development Program Office, National
Aeronautics and Space Agency, Washington, DC. Assistance by Philip Werk,
Benjamin Chan, Jeffrey Taggart (Case Western Reserve University), David
Bennett (Jacobs Sverdrup), Mike Jamison (ZIN Technologies), Gary Ruff,
James Withlow, and John Yaniec (NASA) in conducting the experiment is
acknowledged.
NR 42
TC 17
Z9 17
U1 4
U2 14
PU ELSEVIER SCIENCE INC
PI NEW YORK
PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA
SN 0010-2180
J9 COMBUST FLAME
JI Combust. Flame
PD OCT
PY 2008
VL 155
IS 1-2
BP 37
EP 53
DI 10.1016/j.combustflame.2008.03.005
PG 17
WC Thermodynamics; Energy & Fuels; Engineering, Multidisciplinary;
Engineering, Chemical; Engineering, Mechanical
SC Thermodynamics; Energy & Fuels; Engineering
GA 364VB
UT WOS:000260362400004
ER
PT J
AU Brewer, R
AF Brewer, Ron
TI Systems EMC Design And Analysis Part 1
SO EE-EVALUATION ENGINEERING
LA English
DT Article
C1 NASA, Kennedy Space Ctr, FL USA.
RP Brewer, R (reprint author), NASA, Kennedy Space Ctr, FL USA.
EM ronbrewer@ieee.org
NR 0
TC 0
Z9 0
U1 0
U2 1
PU NELSON PUBLISHING
PI NOKOMIS
PA 2500 NORTH TAMIAMI TRAIL, NOKOMIS, FL 34275-3482 USA
SN 0149-0370
J9 EE-EVAL ENG
JI EE-Eval. Eng.
PD OCT
PY 2008
VL 47
IS 10
BP 58
EP +
PG 5
WC Engineering, Electrical & Electronic
SC Engineering
GA 358XB
UT WOS:000259949700009
ER
PT J
AU Guo, H
Liu, YG
Daum, PH
Senum, GI
Tao, WK
AF Guo, Huan
Liu, Yangang
Daum, Peter H.
Senum, Gunnar I.
Tao, Wei-Kuo
TI Characteristics of vertical velocity in marine stratocumulus: comparison
of large eddy simulations with observations
SO ENVIRONMENTAL RESEARCH LETTERS
LA English
DT Article
DE vertical velocity; subgrid variability; marine stratocumulus
ID LIQUID WATER DISTRIBUTIONS; BOUNDARY-LAYER; SCALE-INVARIANCE; CLOUDS;
MODELS; MICROPHYSICS; SKEWNESS; PARAGON; NUMBER; ISSUES
AB We simulated a marine stratus deck sampled during the Marine Stratus/Stratocumulus Experiment (MASE) with a three-dimensional large eddy simulation (LES) model at different model resolutions. Various characteristics of the vertical velocity from the model simulations were evaluated against those derived from the corresponding aircraft in situ observations, focusing on standard deviation, skewness, kurtosis, probability density function (PDF), power spectrum, and structure function. Our results show that although the LES model captures reasonably well the lower-order moments (e. g., horizontal averages and standard deviations), it fails to simulate many aspects of the higher-order moments, such as kurtosis, especially near cloud base and cloud top. Further investigations of the PDFs, power spectra, and structure functions reveal that compared to the observations, the model generally underestimates relatively strong variations on small scales. The results also suggest that increasing the model resolutions improves the agreements between the model results and the observations in virtually all of the properties that we examined. Furthermore, the results indicate that a vertical grid size <10 m is necessary for accurately simulating even the standard-deviation profile, posing new challenges to computer resources.
C1 [Guo, Huan; Liu, Yangang; Daum, Peter H.; Senum, Gunnar I.] Brookhaven Natl Lab, Div Atmospher Sci, Upton, NY 11973 USA.
[Tao, Wei-Kuo] NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA.
RP Guo, H (reprint author), Brookhaven Natl Lab, Div Atmospher Sci, Bldg 815E,75 Rutherford Dr, Upton, NY 11973 USA.
EM hguo@umich.edu
RI Liu, Yangang/H-6154-2011; Guo, Huan/D-8282-2014
FU US Department of Energy [DE-AC02-98CH10886]; State of New York;
Atmospheric Radiation Observations (ARM); Atmospheric Sciences Programme
(ASP); US Department of Energy/Atmospheric Radiation Measurement
(DOE/ARM) Interagency Agreement [DE-AI02-04ER63755]
FX This research utilized resources at the New York Center for
Computational Sciences at Stony Brook University/Brookhaven National
Laboratory which is supported by the US Department of Energy under
Contract No. DE-AC02-98CH10886 and by the State of New York. Guo, Liu,
and Daum are supported by the Atmospheric Radiation Observations (ARM)
Programme and Atmospheric Sciences Programme (ASP) of the US Department
of Energy under Contract No. DE-AC02-98CH10886. We are very grateful to
Efstratios Efstathiadis, Andy Vogelmann, and James Davenport of BNL for
their continuingly great support and valuable help on the New York Blue
supercomputer. Tao is partially supported by the Office of Science
(BER), and US Department of Energy/Atmospheric Radiation Measurement
(DOE/ARM) Interagency Agreement No. DE-AI02-04ER63755. The GCE model is
mainly supported by the NASA Headquarters Atmospheric Dynamics and
Thermodynamics Programme and the NASA Tropical Rainfall Measuring
Mission (TRMM). The authors are grateful to Dr Kiran Alapaty at DOE/ARM,
Dr AshleyWilliamson at DOE/ASP, and Dr R Kakar at NASA headquarters for
their support of this research. The authors also thank two anonymous
reviewers for their constructive comments that improved this article
considerably.
NR 35
TC 14
Z9 14
U1 2
U2 7
PU IOP PUBLISHING LTD
PI BRISTOL
PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND
SN 1748-9326
J9 ENVIRON RES LETT
JI Environ. Res. Lett.
PD OCT-DEC
PY 2008
VL 3
IS 4
AR 045020
DI 10.1088/1748-9326/3/4/045020
PG 8
WC Environmental Sciences; Meteorology & Atmospheric Sciences
SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences
GA 442YW
UT WOS:000265878400030
ER
PT J
AU Luchinsky, DG
Smelyanskiy, VN
Millonas, M
McClintock, PVE
AF Luchinsky, D. G.
Smelyanskiy, V. N.
Millonas, M.
McClintock, P. V. E.
TI Dynamical inference of hidden biological populations
SO EUROPEAN PHYSICAL JOURNAL B
LA English
DT Article
ID MODELS; RECONSTRUCTION; SYSTEMS; CHAOS
AB Population fluctuations in a predator-prey system are analyzed for the case where the number of prey could be determined, subject to measurement noise, but the number of predators was unknown. The problem of how to infer the unmeasured predator dynamics, as well as the model parameters, is addressed. Two solutions are suggested. In the first of these, measurement noise and the dynamical noise in the equation for predator population are neglected; the problem is reduced to a one-dimensional case, and a Bayesian dynamical inference algorithm is employed to reconstruct the model parameters. In the second solution a full-scale Markov Chain Monte Carlo simulation is used to infer both the unknown predator trajectory, and also the model parameters, using the one-dimensional solution as an initial guess.
C1 [Luchinsky, D. G.; Smelyanskiy, V. N.] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
[Luchinsky, D. G.; McClintock, P. V. E.] Univ Lancaster, Dept Phys, Lancaster LA1 4YB, England.
[Luchinsky, D. G.; Millonas, M.] Mission Crit Technol Inc, El Segundo, CA 90245 USA.
RP Luchinsky, DG (reprint author), NASA, Ames Res Ctr, Mail Stop 269-2, Moffett Field, CA 94035 USA.
EM d.luchinsky@lancaster.ac.uk
RI Luchinsky, Dmitry/N-4177-2014
NR 26
TC 4
Z9 4
U1 0
U2 3
PU SPRINGER
PI NEW YORK
PA 233 SPRING ST, NEW YORK, NY 10013 USA
SN 1434-6028
J9 EUR PHYS J B
JI Eur. Phys. J. B
PD OCT
PY 2008
VL 65
IS 3
BP 369
EP 377
DI 10.1140/epjb/e2008-00340-5
PG 9
WC Physics, Condensed Matter
SC Physics
GA 361IW
UT WOS:000260122300009
ER
PT J
AU Turyshev, SG
AF Turyshev, S. G.
TI Tests of relativistic gravity in space Recent progress and future
directions
SO EUROPEAN PHYSICAL JOURNAL-SPECIAL TOPICS
LA English
DT Article
ID INVERSE-SQUARE LAW; SOLAR GRAVITATIONAL DEFLECTION; NEWLY RECOVERED
DATA; EQUIVALENCE PRINCIPLE; COSMOLOGICAL CONSTANT; LORENTZ INVARIANCE;
GENERAL-RELATIVITY; ACCELERATING UNIVERSE; NUCLEAR RESONANCE;
QUANTUM-GRAVITY
AB We review the foundations of Einstein's general theory of relativity, discuss recent progress in the tests of relativistic gravity, and present motivations for new generation of high-accuracy gravitational experiments. We discuss the advances in our understanding of fundamental physics anticipated in the near future and evaluate discovery potential of the recently proposed gravitational experiments.
C1 [Turyshev, S. G.] CALTECH, Jet Prop Lab, Pasadena, CA 91009 USA.
[Turyshev, S. G.] Moscow MV Lomonosov State Univ, Sternberg Astron Inst, Moscow 119992, Russia.
RP Turyshev, SG (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91009 USA.
NR 163
TC 5
Z9 6
U1 0
U2 1
PU SPRINGER HEIDELBERG
PI HEIDELBERG
PA TIERGARTENSTRASSE 17, D-69121 HEIDELBERG, GERMANY
SN 1951-6355
EI 1951-6401
J9 EUR PHYS J-SPEC TOP
JI Eur. Phys. J.-Spec. Top.
PD OCT
PY 2008
VL 163
BP 227
EP 253
DI 10.1140/epjst/e2008-00822-8
PG 27
WC Physics, Multidisciplinary
SC Physics
GA 372GG
UT WOS:000260889500018
ER
PT J
AU Sako, T
Sekiguchi, T
Sasaki, M
Okajima, K
Abe, F
Bond, IA
Hearnshaw, JB
Itow, Y
Kamiya, K
Kilmartin, PM
Masuda, K
Matsubara, Y
Muraki, Y
Rattenbury, NJ
Sullivan, DJ
Sumi, T
Tristram, P
Yanagisawa, T
Yock, PCM
AF Sako, T.
Sekiguchi, T.
Sasaki, M.
Okajima, K.
Abe, F.
Bond, I. A.
Hearnshaw, J. B.
Itow, Y.
Kamiya, K.
Kilmartin, P. M.
Masuda, K.
Matsubara, Y.
Muraki, Y.
Rattenbury, N. J.
Sullivan, D. J.
Sumi, T.
Tristram, P.
Yanagisawa, T.
Yock, P. C. M.
TI MOA-cam3: a wide-field mosaic CCD camera for a gravitational
microlensing survey in New Zealand
SO EXPERIMENTAL ASTRONOMY
LA English
DT Article
DE CCD cameras; wide-field survey telescope; gravitational microlensing
ID LARGE-MAGELLANIC-CLOUD; GALACTIC BULGE; LENSING EXPERIMENT; PLANET;
DISCOVERY; EVENT
AB We have developed a wide-field mosaic CCD camera, MOA-cam3, mounted at the prime focus of the Microlensing Observations in Astrophysics (MOA) 1.8-m telescope. The camera consists of ten E2V CCD4482 chips, each having 2kx4k pixels, and covers a 2.2 deg(2) field of view with a single exposure. The optical system is well optimized to realize uniform image quality over this wide field. The chips are constantly cooled by a cryocooler at -80 degrees C, at which temperature dark current noise is negligible for a typical 1-3 min exposure. The CCD output charge is converted to a 16-bit digital signal by the GenIII system (Astronomical Research Cameras Inc.) and readout is within 25 s. Readout noise of 2-3 ADU (rms) is also negligible. We prepared a wide-band red filter for an effective microlensing survey and also Bessell V, I filters for standard astronomical studies. Microlensing studies have entered into a new era, which requires more statistics, and more rapid alerts to catch exotic light curves. Our new system is a powerful tool to realize both these requirements.
C1 [Sako, T.; Sekiguchi, T.; Sasaki, M.; Okajima, K.; Abe, F.; Itow, Y.; Kamiya, K.; Masuda, K.; Matsubara, Y.; Muraki, Y.; Sumi, T.] Nagoya Univ, Solar Terr Environm Lab, Nagoya, Aichi 4648601, Japan.
[Bond, I. A.] Massey Univ, Inst Informat & Math Sci, Auckland, New Zealand.
[Hearnshaw, J. B.; Kilmartin, P. M.; Tristram, P.] Univ Canterbury, Dept Phys & Astron, Christchurch 1, New Zealand.
[Rattenbury, N. J.] Univ Manchester, Jodrell Bank Observ, Macclesfield, Cheshire, England.
[Sullivan, D. J.] Victoria Univ, Sch Chem & Phys Sci, Wellington, New Zealand.
[Yanagisawa, T.] Japan Aerosp Explorat Agcy JAXA, Adv Space Technol Res Grp, Inst Aerosp Technol, Tokyo, Japan.
[Yanagisawa, T.] NASA, Orbital Debris Program Off, Washington, DC 20546 USA.
[Yock, P. C. M.] Univ Auckland, Dept Phys, Auckland, New Zealand.
RP Sako, T (reprint author), Nagoya Univ, Solar Terr Environm Lab, Nagoya, Aichi 4648601, Japan.
EM sako@stelab.nagoya-u.ac.jp
FU Japan Ministry of Education, Science, Sports and Culture
FX This work is supported by a grant-in-aid for scientific research of the
Japan Ministry of Education, Science, Sports and Culture. The authors
are grateful to the staff of the National Astronomical Observatory Japan
(Y. Kobayashi, S. Miyazaki, Y. Komiyama, H. Nakaya), to members of the
Graduate School of Science (S. Sato, H. Shibai) and Instrument
Development Group of the Technical Center of Nagoya University, to J.
Hiraga in ISAS/JAXA, to staff of the Nishimura Co. Ltd., to H. Kondoh in
AISIN, to A. Rakich in IRL and to B. Leach in ARC. Finally, the authors
thank the anonymous reviewer for improving the manuscript and for
general expert comments on the camera.
NR 16
TC 38
Z9 38
U1 1
U2 6
PU SPRINGER
PI DORDRECHT
PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS
SN 0922-6435
J9 EXP ASTRON
JI Exp. Astron.
PD OCT
PY 2008
VL 22
IS 1-2
BP 51
EP 66
DI 10.1007/s10686-007-9082-5
PG 16
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 348ZC
UT WOS:000259247600003
ER
PT J
AU Stoner, AW
Rose, CS
Munk, JE
Hammond, CF
Davis, MW
AF Stoner, Allan W.
Rose, Craig S.
Munk, J. Eric
Hammond, Carwyn F.
Davis, Michael W.
TI An assessment of discard mortality for two Alaskan crab species, Tanner
crab (Chionoecetes bairdi) and snow crab (C. opilio), based on reflex
impairment
SO FISHERY BULLETIN
LA English
DT Article
ID NEPHROPS-NORVEGICUS; NORWAY LOBSTER; AIR EXPOSURE; FISHERY; KING;
SABLEFISH; RESPONSES; RECOVERY; SURVIVAL; CAPTURE
AB Delayed mortality associated with discarded crabs and fishes has ordinarily been observed through tag and recovery studies or during prolonged holding in deck tanks, and there is need for a more efficient assessment method. Chionoecetes bairdi (Tanner crab) and C. opilio (snow crab) collected with bottom trawls in Bering Sea waters off Alaska were evaluated for reflexes and injuries and held onboard to track mortality. Presence or absence of six reflex actions was determined and combined to calculate a reflex impairment index for each species. Logistic regression revealed that reflex impairment provided an excellent predictor of delayed mortality in C. opilio (91% correct predictions). For C. bairdi, reflex impairment, along with injury score, resulted in 82.7% correct predictions of mortality, and reflex impairment alone resulted in 79.5% correct predictions. The relationships between reflex impairment score and mortality were independent of crab gender, size, and shell condition, and predicted mortality in crabs with no obvious external damage. These relationships provide substantial improvement over earlier predictors of mortality and will help to increase the scope and replication of fishing and handling experiments. The general approach of using reflex actions to predict mortality should be equally valuable for a wide range of crustacean species.
C1 [Stoner, Allan W.; Davis, Michael W.] NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Fisheries Behav Ecol Program, Newport, OR 97365 USA.
[Rose, Craig S.; Hammond, Carwyn F.] NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Conservat Engn Program, Seattle, WA 98115 USA.
[Munk, J. Eric] NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Shellfish Assessment Program, Kodiak, AK 99615 USA.
RP Stoner, AW (reprint author), NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Fisheries Behav Ecol Program, 2030 Marine Sci Dr, Newport, OR 97365 USA.
EM Al.Stoner@noaa.gov
FU National Oceanic and Atmospheric Administration Byeatch Reduction
Program; North Pacific Research Board
FX This project was funded in part by the National Oceanic and Atmospheric
Administration Byeatch Reduction Program and the North Pacific Research
Board. D. King and J. Smart prepared the recapture nets, S. McEntire
assisted with electronics, S. McDermott loaned the deck boxes for
holding crabs, and S. Walters and K.-H. Lee participated in the field
study. We are grateful to Captain R. Haddon and crew of the FV Pacific
Explorer for assistance with tank set-ups and handling our
unconventional fishing gear. T. Hurst provided suggestions on
statistical approach and anonymous reviewers helped to improve the
manuscript.
NR 28
TC 16
Z9 16
U1 1
U2 4
PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE
PI SEATTLE
PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 USA
SN 0090-0656
J9 FISH B-NOAA
JI Fish. Bull.
PD OCT
PY 2008
VL 106
IS 4
BP 337
EP 347
PG 11
WC Fisheries
SC Fisheries
GA 371YG
UT WOS:000260868000001
ER
PT J
AU Rodgveller, CJ
Lunsford, CR
Fujioka, JT
AF Rodgveller, Cara J.
Lunsford, Chris R.
Fujioka, Jeffrey T.
TI Evidence of hook competition in longline surveys
SO FISHERY BULLETIN
LA English
DT Article
ID SABLEFISH ANOPLOPOMA-FIMBRIA; BEHAVIORAL-RESPONSES; SELECTIVITY;
FISHERY; TEMPERATURE; ABUNDANCE; GREENLAND; ATLANTIC; TRAWL; GEAR
AB Catch rates from surveys are used as indices of abundance for many fish species. Relative abundance estimates from surveys with longline gear do not usually account for possible effects of gear saturation, which potentially creates competition among fish for baited hooks and misrepresentations of abundance trends. We examined correlations between catch rates of sablefish (Anoplopoma fimbria) and giant grenadier (Albatrossia pectoralis) and between sablefish and shortraker (Sebastes borealis) and rougheye rockfish (Sebastes aleutianus) from 25 years of longline surveys in Alaska waters for evidence of competition for hooks. Sablefish catch rates were negatively correlated with giant grenadier catch rates in all management areas in Alaskan waters, and sablefish and rockfish were negatively correlated in five of the six areas, indicating that there is likely competition for hooks during longline surveys. Comparative analyses were done for trawl survey catch rates, and no negative correlations were observed, indicating that the negative correlations on the longline surveys are not due to differing habitat preferences or direct competition. Available adjustments for gear saturation may be biased if the probability of capture does not decrease linearly with baited hooks. A better understanding of each fish species' catch probabilities on longline gear are needed before adjustments for hook competition can be made.
C1 [Rodgveller, Cara J.; Lunsford, Chris R.; Fujioka, Jeffrey T.] NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Auke Bay Labs, Juneau, AK 99801 USA.
RP Rodgveller, CJ (reprint author), NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Auke Bay Labs, 17109 Point Lena Loop Rd, Juneau, AK 99801 USA.
EM Cara.Rodgveller@noaa.gov
NR 26
TC 4
Z9 4
U1 2
U2 4
PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE
PI SEATTLE
PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 USA
SN 0090-0656
J9 FISH B-NOAA
JI Fish. Bull.
PD OCT
PY 2008
VL 106
IS 4
BP 364
EP 374
PG 11
WC Fisheries
SC Fisheries
GA 371YG
UT WOS:000260868000003
ER
PT J
AU Brill, R
Magel, C
Davis, M
Hannah, R
Rankin, P
AF Brill, Richard
Magel, Christopher
Davis, Michael
Hannah, Robert
Rankin, Polly
TI Effects of rapid decompression and exposure to bright light on visual
function in black rockfish (Sebastes melanops) and Pacific halibut
(Hippoglossus stenolepis)
SO FISHERY BULLETIN
LA English
DT Article
ID REFLEX IMPAIRMENT; DISCARD MORTALITY; CAPTURE DEPTH; FISH; PIGMENTS;
RELEASE; BYCATCH; RETINA; AIR; PHOTORECEPTORS
AB Demersal Fishes hauled up from depth experience rapid decompression. In physoclists, this can cause overexpansion of the swim bladder and resultant injuries to multiple organs (barotrauma), including severe exophthalmia ("pop-eye"). Before release, fishes can also be subjected to asphyxia and exposure to direct sunlight. Little is known, however, about possible sensory deficits resulting from the events accompanying capture. To address this issue, electroretinography was used to measure the changes in retinal light sensitivity, flicker fusion frequency, and spectral sensitivity in black rockfish (Sebastes melanops) subjected to rapid decompression (from 4 atmospheres absolute [ATA] to 1 ATA) and Pacific halibut (Hippoglossus stenolepis) exposed to 15 minutes of simulated sunlight. Rapid decompression had no measurable influence on retinal function in black rockfish. In contrast, exposure to bright light significantly reduced retinal light sensitivity of Pacific halibut, predominately by affecting the photopigment which absorbs the green wavelengths of light (approximate to 520-580 nm) most strongly. This detriment is likely to have severe consequences for postrelease foraging success in green-wavelength-dominated coastal waters. The visual system of Pacific halibut has characteristics typical of species adapted to low light environments, and these characteristics may underlie their vulnerability to injury from exposure to bright light.
C1 [Brill, Richard] NOAA, Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, Cooperat Marine Educ & Res Program, Woods Hole, MA 02543 USA.
[Magel, Christopher] Virginia Inst Marine Sci, Gloucester Point, VA 23062 USA.
[Davis, Michael] NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Fisheries Behav Ecol Program, Newport, OR 97365 USA.
[Hannah, Robert; Rankin, Polly] Hatfield Marine Sci Ctr, Oregon Dept Fish & Wildlife, Newport, OR 97365 USA.
RP Brill, R (reprint author), NOAA, Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, Cooperat Marine Educ & Res Program, Woods Hole, MA 02543 USA.
EM rbrill@vims.edu
NR 48
TC 18
Z9 18
U1 0
U2 2
PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE
PI SEATTLE
PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 USA
SN 0090-0656
J9 FISH B-NOAA
JI Fish. Bull.
PD OCT
PY 2008
VL 106
IS 4
BP 427
EP 437
PG 11
WC Fisheries
SC Fisheries
GA 371YG
UT WOS:000260868000009
ER
PT J
AU Chen, H
Perchonok, M
AF Chen, H.
Perchonok, M.
TI US Governmental Interagency Programs, Opportunities, and Collaboration
SO FOOD SCIENCE AND TECHNOLOGY INTERNATIONAL
LA English
DT Article
DE Government; CREES; ARS; FSIS; USDA; FDA; Natick; DOD; DHHS; NASA
AB Improving the quality, value, and safety of national food supplies is the common mission of several Federal agencies. Under different authorities, these agencies conduct basic and applied research, develop curriculum at higher educational institutions, and disseminate new scientific knowledge about food processing, formulation, and preservation to a broad range of stakeholders. Emerging food processing technologies, including various thermal and nonthermal processes, as well as chemical processes, have received increased attention and investment in recent years. Some agencies dealing with Emerging Technologies include the Cooperative State Research, Education, and Extension Service (CSREES), Agricultural Research Service (ARS), and Food Safety Inspection Service (FSIS), and all of the United States Department of Agriculture (USDA). The U. S. Army Natick Research Center of Department of Defense (DOD), National Aeronautics and Space Administration (NASA), and Food and Drug Administration (FDA) of Department of Human Health Service (DHHS) also are involved in this research area. These agencies have their vision, mission, strategic goals, and current programs and activities related to emerging food processing technologies. The synergy of effective collaboration and cooperation among all stakeholders is the key to generating an impact greater than the simple sum of all.
C1 [Chen, H.] USDA, Bioproc Engn, CSREES, Washington, DC 20250 USA.
[Perchonok, M.] NASA, JSC, Houston, TX 77058 USA.
RP Chen, H (reprint author), USDA, Bioproc Engn, CSREES, Washington, DC 20250 USA.
EM hchen@csrees.usda.gov
NR 0
TC 0
Z9 0
U1 1
U2 6
PU SAGE PUBLICATIONS LTD
PI LONDON
PA 1 OLIVERS YARD, 55 CITY ROAD, LONDON EC1Y 1SP, ENGLAND
SN 1082-0132
J9 FOOD SCI TECHNOL INT
JI Food Sci. Technol. Int.
PD OCT
PY 2008
VL 14
IS 5
BP 447
EP 453
DI 10.1177/1082013208098817
PG 7
WC Chemistry, Applied; Food Science & Technology
SC Chemistry; Food Science & Technology
GA 396SI
UT WOS:000262611000010
ER
PT J
AU Downes, H
Mittlefehldt, DW
Kita, NT
Valley, JW
AF Downes, Hilary
Mittlefehldt, David W.
Kita, Noriko T.
Valley, John W.
TI Evidence from polymict ureilite meteorites for a disrupted and
re-accreted single ureilite parent asteroid gardened by several distinct
impactors
SO GEOCHIMICA ET COSMOCHIMICA ACTA
LA English
DT Article
ID ANTARCTIC UREILITES; OXYGEN-ISOTOPE; CARBONACEOUS CHONDRITE; MAGMATIC
INCLUSIONS; ORIGIN; BODY; MINERALOGY; OLIVINE; CLASTS; CONSTRAINTS
AB Ureilites are ultramafic achondrites that exhibit heterogeneity in mg# and oxygen isotope ratios between different meteorites. Polymict ureilites represent near-surface material of the ureilite parent asteroid(s). Electron microprobe analyses of >500 olivine and pyroxene clasts in several polymict ureilites reveal a statistically identical range of compositions to that shown by unbrecciated ureilites, suggesting derivation from a single parent asteroid. Many ureilitic clasts have identical compositions to the anomalously high Mn/Mg olivines and pyroxenes from the Hughes 009 unbrecciated ureilite (here termed the "Hughes cluster"). Some polymict samples also contain lithic clasts derived from oxidized impactors. The presence of several common distinctive lithologies within polymict ureilites is additional evidence that ureilites were derived from a single parent asteroid.
In situ oxygen three isotope analyses were made on individual ureilite minerals and lithic clasts, using a secondary ion mass spectrometer (SIMS) with precision typically better than 0.2-0.47 parts per thousand (2SD) for delta O-18 and delta O-17. Oxygen isotope ratios of ureilitic clasts fall on a narrow trend along the CCAM line, covering the range for unbrecciated ureilites, and show a good anti-correlation with mineral mg#. SIMS analysis identifies one ferroan lithic clast as an R-chondrite, while a second ferroan clast is unlike any known meteorite. An exotic enstatite grain is derived from an enstatite chondrite or aubrite, and another pyroxene grain with Delta O-17 of -0.4 +/- 0.2 parts per thousand is unrelated to any known meteorite type.
Ureilitic olivine clasts with mg#s < 85 are much more common than those with mg# > 85 which include the melt-inclusion-bearing "Hughes cluster" ureilites. Thus melt was present in regions of the parent ureilite asteroid with a bulk mg# > 85 when the asteroid was disrupted by impact, giving rise to two types of ureilites: common ferroan ones that were residual after melting and less common magnesian ones that were still partially molten when disruption occurred. One or more daughter asteroids re-accreted from the remnants of the mantle of the proto-ureilite asteroid. Polymict ureilite meteorites represent regolith that subsequently formed on the surface of a daughter asteroid, including impact-derived material from at least six different meteoritic sources. (C) 2008 Elsevier Ltd. All rights reserved.
C1 [Downes, Hilary] Univ London Birkbeck Coll, Sch Earth Sci, London WC1E 7HX, England.
[Downes, Hilary] Lunar & Planetary Inst, Houston, TX 77058 USA.
[Mittlefehldt, David W.] NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA.
[Kita, Noriko T.; Valley, John W.] Univ Wisconsin, Dept Geol & Geophys, Madison, WI 53706 USA.
RP Downes, H (reprint author), Univ London Birkbeck Coll, Sch Earth Sci, Malet St, London WC1E 7HX, England.
EM h.downes@ucl.ac.uk
RI Valley, John/B-3466-2011; Kita, Noriko/H-8035-2016
OI Valley, John/0000-0003-3530-2722; Kita, Noriko/0000-0002-0204-0765
FU NSF [EAR-0319230, 0509639]; NASA [NNX07Al46G]
FX We thank the Meteorite Working Group for providing the EET samples, Alex
Bevan for the sections of North Haig, and Cyrena Goodrich for loaning
the sections of Nilpena and providing data for Fig. 3. Barbara Cohen
kindly provided the data for minerals in melt clasts. DaG samples were
purchased from Erich Haiderer. We thank Craig Schwandt and GeorgAnn
Robinson for help with the SEM and electron microprobe, respectively.
Reviews by Steve Singletary, Ed Scott and Yukio Ikeda were stimulating
and helpful. We thank Hiroko Nagahara for guiding this paper through the
review process. This work was supported by the Lunar and Planetary
Institute (H.D.) and the NASA Cosmochemistry Program (D.W.M. and N.K.).
The WiscSIMS ion microprobe lab is supported by NSF (EAR-0319230,
0509639) and NASA Grant NNX07Al46G.
NR 69
TC 57
Z9 57
U1 0
U2 7
PU PERGAMON-ELSEVIER SCIENCE LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
SN 0016-7037
J9 GEOCHIM COSMOCHIM AC
JI Geochim. Cosmochim. Acta
PD OCT 1
PY 2008
VL 72
IS 19
BP 4825
EP 4844
DI 10.1016/j.gca.2008.06.028
PG 20
WC Geochemistry & Geophysics
SC Geochemistry & Geophysics
GA 355NZ
UT WOS:000259716900012
ER
PT J
AU Gordon, RG
Argus, DF
Royer, JY
AF Gordon, Richard G.
Argus, Donald F.
Royer, Jean-Yves
TI Space geodetic test of kinematic models for the Indo-Australian
composite plate
SO GEOLOGY
LA English
DT Article
DE plate tectonics; diffuse plate boundaries; component plates; composite
plates; space geodesy; marine geophysics; Capricorn plate
ID EQUATORIAL INDIAN-OCEAN; DISTRIBUTED LITHOSPHERIC DEFORMATION;
INTRAPLATE DEFORMATION; TIME-SCALE; MOTION; CAPRICORN; RECONSTRUCTIONS;
HYPOTHESIS; BOUNDARY; MA
AB The existence of a distinct Capricorn component plate within the composite Indo-Australian plate has previously been questioned. If there is no Capricorn plate, the global positioning system site at Bangalore (on the Indian plate) is predicted to move relative to the Australian plate at a velocity of 10 mm yr(-1). If there is a distinct Capricorn plate, Bangalore is predicted to move relative to the Australian plate at a velocity of 17 mm yr(-1). Space geodetic data from Australia and India are accurate enough to provide quantitative tests of this prediction and to discriminate between alternative composite plate models. The data best fit a composite plate model that assumes the existence of a distinct Capricorn component plate moving relative to both the Indian and Australian component plates.
C1 [Gordon, Richard G.] Rice Univ, Dept Earth Sci, Houston, TX 77005 USA.
[Argus, Donald F.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[Royer, Jean-Yves] Univ Brest, Univ Europeenne Bretagne, CNRS, UMR Domaines Ocean 6538, F-29280 Plouzane, France.
RP Gordon, RG (reprint author), Rice Univ, Dept Earth Sci, Houston, TX 77005 USA.
EM rgg@rice.edu
RI Royer, Jean-Yves/B-4312-2010; Argus, Donald/F-7704-2011
OI Royer, Jean-Yves/0000-0002-7653-7715;
FU National Science Foundation (NSF) [OCE-0242904, OCE-0453219]
FX Gordon's contributions were supported by National Science Foundation
(NSF) grants OCE-0242904 and OCE-0453219. Argus's part of this research
was performed at the Jet Propulsion Laboratory, California Institute of
Technology, under contract with the National Aeronautics and Space
Administration. Collaborative research between Royer and Gordon was
facilitated by the Centre National de la Recherche Scientifique-NSF
international cooperation program.
NR 22
TC 8
Z9 8
U1 0
U2 3
PU GEOLOGICAL SOC AMER, INC
PI BOULDER
PA PO BOX 9140, BOULDER, CO 80301-9140 USA
SN 0091-7613
J9 GEOLOGY
JI Geology
PD OCT
PY 2008
VL 36
IS 10
BP 827
EP 830
DI 10.1130/G25089A.1
PG 4
WC Geology
SC Geology
GA 357HB
UT WOS:000259835800019
ER
PT J
AU Issautier, K
Le Chat, G
Meyer-Vernet, N
Moncuquet, M
Hoang, S
MacDowall, RJ
McComas, DJ
AF Issautier, K.
Le Chat, G.
Meyer-Vernet, N.
Moncuquet, M.
Hoang, S.
MacDowall, R. J.
McComas, D. J.
TI Electron properties of high-speed solar wind from polar coronal holes
obtained by Ulysses thermal noise spectroscopy: Not so dense, not so hot
SO GEOPHYSICAL RESEARCH LETTERS
LA English
DT Article
ID PLASMA; MAXIMUM; TEMPERATURE; HELIOSPHERE; PARAMETERS; MODELS; SUN
AB We present radio observations of Ulysses' third fast latitude scan near the 2007 solar activity minimum of cycle 23. We deduce in situ measurements of the electron density and temperature using the method of quasi-thermal noise spectroscopy. We study the large-scale properties of the fast solar wind coming from polar coronal holes and compare our results to those obtained during Ulysses' first fast scan in 1994-1995 near the minimum of cycle 22. The fast solar wind in both hemispheres is less dense and cooler by about 19% and 13% respectively, as compared to the last solar minimum.
C1 [Issautier, K.; Le Chat, G.; Meyer-Vernet, N.; Moncuquet, M.; Hoang, S.] Univ Paris Diderot, CNRS, UPMC,Observ Parid, Lab Etud Spatiales & Instrumentat Astrophys, F-92195 Meudon, France.
[MacDowall, R. J.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
[McComas, D. J.] SW Res Inst, San Antonio, TX 78228 USA.
RP Issautier, K (reprint author), Univ Paris Diderot, CNRS, UPMC,Observ Parid, Lab Etud Spatiales & Instrumentat Astrophys, 5 Pl Jules Janssen, F-92195 Meudon, France.
EM karine.issautier@obspm.fr
RI MacDowall, Robert/D-2773-2012
FU CNES; CNRS
FX The Ulysses URAP investigation is a collaboration of NASA/GSFC,
Observatoire de Paris, University of Minnesota, and CETP, Velizy,
France. The French contribution is supported by CNES and CNRS. We thank
the SOHO/EIT instrument team, the SOHO/LASCO instrument team and the
High Altitude Mauna Loa coronograph team for providing composite solar
images of Figure 4.
NR 23
TC 32
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U1 0
U2 1
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0094-8276
J9 GEOPHYS RES LETT
JI Geophys. Res. Lett.
PD OCT 1
PY 2008
VL 35
IS 19
AR L19101
DI 10.1029/2008GL034912
PG 5
WC Geosciences, Multidisciplinary
SC Geology
GA 356UL
UT WOS:000259803000004
ER
PT J
AU Buccello-Stout, R
Cromwell, R
Bloomberg, J
AF Buccello-Stout, R.
Cromwell, R.
Bloomberg, J.
TI CHANGES IN HEAD STABILITY CONTROL IN RESPONSE TO A LATERAL PERTURBATION
WHILE WALKING IN OLDER ADULTS
SO GERONTOLOGIST
LA English
DT Meeting Abstract
C1 [Buccello-Stout, R.; Cromwell, R.] Univ Space Res Assoc, Houston, TX USA.
[Bloomberg, J.] NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA.
NR 0
TC 0
Z9 0
U1 0
U2 0
PU OXFORD UNIV PRESS INC
PI CARY
PA JOURNALS DEPT, 2001 EVANS RD, CARY, NC 27513 USA
SN 0016-9013
EI 1758-5341
J9 GERONTOLOGIST
JI Gerontologist
PD OCT
PY 2008
VL 48
SI 3
BP 630
EP 630
PG 1
WC Gerontology
SC Geriatrics & Gerontology
GA 399PA
UT WOS:000262810602446
ER
PT J
AU Peters, GH
Abbey, W
Bearman, GH
Mungas, GS
Smith, JA
Anderson, RC
Douglas, S
Beegle, LW
AF Peters, Gregory H.
Abbey, William
Bearman, Gregory H.
Mungas, Gregory S.
Smith, J. Anthony
Anderson, Robert C.
Douglas, Susanne
Beegle, Luther W.
TI Mojave Mars simulant - Characterization of a new geologic Mars analog
SO ICARUS
LA English
DT Article
DE Mars, surface; geological processes; experimental techniques; regoliths
ID MAGNETIC-PROPERTIES EXPERIMENTS; X-RAY SPECTROMETER; MINI-TES
EXPERIMENT; GUSEV CRATER; MERIDIANI-PLANUM; SPIRIT ROVER; OPPORTUNITY
ROVER; MARTIAN ATMOSPHERE; MICROSCOPIC IMAGER; SOIL SIMULANT
AB We have identified and characterized a basaltic Mars simulant that is available as whole rocks, sand and dust. The source rock for the simulant is a basalt mined from the Tertiary Tropico Group in the western Mojave Desert. The Mojave Mars Simulant (MMS) was chosen for its inert hygroscopic characteristics, its availability in a variety of forms, and its physical and chemical characteristics. The MMS dust and MMS sand are produced by mechanically crushing basaltic boulders. This is a process that More closely resembles the weathering/comminution processes on Mars where impact events and aerodynamic interactions provide comminution in the (relative) absence of water and organics. MMS is among the Suite of test rocks and soils that Was used in the development of the 2007/8 Phoenix Scout and is being used in the 2009 Mars Science Laboratory (MSL) missions. The MMS development team is using the simulant for research that centers on sampling tool interactions in icy soils. Herein we describe the physical properties and chemical composition of this new Mars simulant. (C) 2008 Elsevier Inc. All rights reserved.
C1 [Abbey, William; Anderson, Robert C.; Douglas, Susanne; Beegle, Luther W.] CALTECH, Jet Prop Lab, Planetary Sci Sect, Pasadena, CA 91109 USA.
[Peters, Gregory H.; Bearman, Gregory H.; Mungas, Gregory S.; Smith, J. Anthony] CALTECH, Jet Prop Lab, In Situ Instrument Syst Sect, Pasadena, CA 91109 USA.
RP Beegle, LW (reprint author), CALTECH, Jet Prop Lab, Planetary Sci Sect, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM luther.beegle@jpl.nasa.gov
RI Beegle, Luther/A-6354-2010
FU RTD
FX This research was carried out at the Extraterrestrial Material
Simulation Laboratory at the jet Propulsion Laboratory, California
Institute of Technology, and was supported under internal RT&D funding.
We wish to acknowledge David Oliver of Select Resources for the initial
tour of the basalt mining facilities and for providing the geochemical
data; Brandon Griffiths of US Borax for arranging a tour of the borax
mine and providing information regarding the local stratigrphy; Marshal
Petit of Carlton Global Resources for allowing access to the crushing
and screening facilities and for providing both samples and processing
information; and Tim Thomson of Earth Systems Engineering for performing
the direct shear and particle size distribution tests. We would also
like to thank Dr. Pamela Conrad of JPL for graciously allowing us access
to her Bruker X-ray diffractometer. Finally we greatly appreciate the
comments from two anonymous reviewers for immeasurably improving this
paper.
NR 61
TC 31
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U1 1
U2 22
PU ACADEMIC PRESS INC ELSEVIER SCIENCE
PI SAN DIEGO
PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA
SN 0019-1035
EI 1090-2643
J9 ICARUS
JI Icarus
PD OCT
PY 2008
VL 197
IS 2
BP 470
EP 479
DI 10.1016/j.icarus.2008.05.004
PG 10
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 356OT
UT WOS:000259788200007
ER
PT J
AU Paranicas, C
Mitchell, DG
Krimigis, SM
Hamilton, DC
Roussos, E
Krupp, N
Jones, GH
Johnson, RE
Cooper, JF
Armstrong, TP
AF Paranicas, C.
Mitchell, D. G.
Krimigis, S. M.
Hamilton, D. C.
Roussos, E.
Krupp, N.
Jones, G. H.
Johnson, R. E.
Cooper, J. F.
Armstrong, T. P.
TI Sources and losses of energetic protons in Saturn's magnetosphere
SO ICARUS
LA English
DT Article
DE Saturn, magnetosphere; Saturn, satellites; Saturn, rings; satellites,
surfaces
ID G-RING; ENCELADUS; HYDROGEN; PLASMA; TORUS
AB We present Cassini data revealing that protons between a few keV and about 100 keV energy are not stably trapped in Saturn's inner magnetosphere. Instead these ions are present only for relatively short times following injections. Injected Protons are lost principally because the neutral gas cloud converts these particles to energetic neutral atoms via charge exchange. At higher energies, in the MeV to GeV range, protons are stably trapped between the orbits of the principal moons because the proton cross-section for charge exchange is very small at such energies. These protons likely result from cosmic ray albedo neutron decay (CRAND) and are lost principally to interactions with satellite surfaces and ring particles during magnetospheric radial diffusion. A main result of this work is to show that the dominant energetic proton loss and source processes are a function of proton energy. Surface sputtering by keV ions is revisited based on the reduced ion intensities observed. Relatively speaking, MeV ion and electron weathering is most important closer to Saturn, e.g. at Janus and Mimas, whereas keV ion weathering is most important farther out, at Dione and Rhea. (C) 2008 Elsevier Inc. All rights reserved.
C1 [Paranicas, C.; Mitchell, D. G.; Krimigis, S. M.] Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA.
[Hamilton, D. C.] Univ Maryland, Dept Phys, College Pk, MD 20742 USA.
[Roussos, E.; Krupp, N.] Max Planck Inst Sonnensyst Forsch, D-37191 Katlenburg Lindau, Germany.
[Jones, G. H.] Univ Coll London, Mullard Space Sci Lab, Dorking RH5 6NT, Surrey, England.
[Jones, G. H.] UCL, Ctr Planetary Sci, London WC1E 6BT, England.
[Johnson, R. E.] Univ Virginia, Charlottesville, VA 22904 USA.
[Cooper, J. F.] NASA, Goddard Space Flight Ctr, Heliospher Phys Lab, Greenbelt, MD 20771 USA.
[Armstrong, T. P.] Fundamental Technologies, Lawrence, KS 66046 USA.
RP Paranicas, C (reprint author), Johns Hopkins Univ, Appl Phys Lab, MS MP3-E128,11100 Johns Hopkins Rd, Laurel, MD 20723 USA.
EM chris.paranicas@jhuapl.edu
RI Roussos, Elias/H-2249-2011; Cooper, John/D-4709-2012; Jones,
Geraint/C-1682-2008; Paranicas, Christopher/B-1470-2016
OI Hamilton, Douglas/0000-0001-6103-8019; Roussos,
Elias/0000-0002-5699-0678; Jones, Geraint/0000-0002-5859-1136;
Paranicas, Christopher/0000-0002-4391-8255
FU Science and Technology Facilities Council, UK; NASA; JHU/APL; NASA jet
Propulsion Laboratory [1243218]; Southwest Research Institute in San
Antonio
FX We appreciate the help of M. Hedman. G.H.J. acknowledges the support of
the Science and Technology Facilities Council, UK. This work was partly
supported by grants between NASA and JHU/APL. JFC is partly supported by
the Cassini Plasma Spectrometer project at NASA Goddard through NASA jet
Propulsion Laboratory contract 1243218 with the Southwest Research
Institute in San Antonio.
NR 35
TC 38
Z9 38
U1 0
U2 4
PU ACADEMIC PRESS INC ELSEVIER SCIENCE
PI SAN DIEGO
PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA
SN 0019-1035
J9 ICARUS
JI Icarus
PD OCT
PY 2008
VL 197
IS 2
BP 519
EP 525
DI 10.1016/j.icarus.2008.05.011
PG 7
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 356OT
UT WOS:000259788200011
ER
PT J
AU Jaumann, R
Brown, RH
Stephan, K
Barnes, JW
Soderblom, LA
Sotin, C
Le Mouelic, S
Clark, RN
Soderblom, J
Buratti, BJ
Wagner, R
McCord, TB
Rodriguez, S
Baines, KH
Cruikshank, DP
Nicholson, PD
Griffith, CA
Langhans, M
Lorenz, RD
AF Jaumann, Ralf
Brown, Robert H.
Stephan, Katrin
Barnes, Jason W.
Soderblom, Larry A.
Sotin, Christophe
Le Mouelic, Stephane
Clark, Roger N.
Soderblom, Jason
Buratti, Bonnie J.
Wagner, Roland
McCord, Thomas B.
Rodriguez, Sebastien
Baines, Kevin H.
Cruikshank, Dale P.
Nicholson, Phil D.
Griffith, Caitlin A.
Langhans, Mirjam
Lorenz, Ralph D.
TI Fluvial erosion and post-erosional processes on Titan
SO ICARUS
LA English
DT Article
DE Titan; Saturn, satellites; satellites, surfaces; spectroscopy;
geological processes; ices
ID CASSINI RADAR OBSERVATIONS; SEDIMENT TRANSPORT; SURFACE; VIMS; CHANNELS;
METHANE; SCIENCE; MAPPER
AB The surface of Titan has been revealed by Cassini observations in the infrared and radar wavelength ranges as well as locally by the Huygens lander instruments. Sand seas, recently discovered lakes, distinct landscapes and dendritic erosion patterns indicate dynamic surface processes. This study focus on erosional and depositional features that can be used to constrain the amount of liquids involved in the erosional process as well as on the compositional characteristics of depositional areas. Fluvial erosion channels on Titan as identified at the Huygens landing site and in RADAR and Visible and Infrared Mapping Spectrometer (VIMS) observations have been compared to analogous channel widths on Earth yielding average discharges of up to 1600 m(3)/s for short recurrence intervals that are sufficient to move centimeter-sized sediment and significantly higher discharges for long intervals. With respect to the associated drainage areas, this roughly translates to 1-150 cm/day runoff production rates with 10 years recurrence intervals and by assuming precipitation this implies 0.6-60 mm/h rainfall rates. Thus the observed surface erosion fits with the methane convective storm models as well as with the rates needed to transport sediment. During Cassini's T20 fly-by, the VIMS observed an extremely eroded area at 30 degrees W, 7 degrees S with resolutions of up to 500 m/pixel that extends over thousands of square kilometers. The spectral characteristics of this area change systematically, reflecting continuous compositional and/or particle size variations indicative of transported sediment settling out while flow capacities cease. To account for the estimated runoff production and widespread alluvial deposits of fine-grained material, release of area-dependent large fluid volumes are required. Only frequent storms with heavy rainfall or cryovolcanic induced melting can explain these erosional features. (C) 2008 Elsevier Inc. All rights reserved.
C1 [Jaumann, Ralf; Stephan, Katrin; Wagner, Roland; Langhans, Mirjam] DLR, Inst Planetary Res, D-12489 Berlin, Germany.
[Jaumann, Ralf] Free Univ Berlin, Inst Geosci, Dept Earth Sci, D-1000 Berlin, Germany.
[Brown, Robert H.; Barnes, Jason W.; Soderblom, Jason; Griffith, Caitlin A.] Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA.
[Soderblom, Larry A.] US Geol Survey, Flagstaff, AZ 86011 USA.
[Sotin, Christophe; Le Mouelic, Stephane; Rodriguez, Sebastien] Univ Nantes, F-44072 Nantes 3, France.
[Clark, Roger N.] US Geol Survey, Denver Fed Ctr, Denver, CO 80225 USA.
[Buratti, Bonnie J.; Baines, Kevin H.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[McCord, Thomas B.] Bear Fight Ctr, Winthrop, WA 98862 USA.
[Cruikshank, Dale P.] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
[Nicholson, Phil D.] Cornell Univ, Dept Astron, Ithaca, NY 14853 USA.
[Lorenz, Ralph D.] Johns Hopkins Univ, Appl Phys Lab, Dept Space, Laurel, MD 20723 USA.
RP Jaumann, R (reprint author), DLR, Inst Planetary Res, Rutherford Str 2, D-12489 Berlin, Germany.
EM ralf.jaumann@dlr.de
RI Barnes, Jason/B-1284-2009; Lorenz, Ralph/B-8759-2016; Rodriguez,
Sebastien/H-5902-2016
OI Barnes, Jason/0000-0002-7755-3530; Soderblom, Jason/0000-0003-3715-6407;
Lorenz, Ralph/0000-0001-8528-4644; Rodriguez,
Sebastien/0000-0003-1219-0641
FU NASA; ESA; DLR; ASI; CNES; JPL; University of Arizona
FX We gratefully acknowledge the long years of work by the entire Cassini
team that allowed these data of Titan to be obtained. We also
acknowledge NASA, ESA, DLR, ASI, CNES, JPL, and the University of
Arizona that provide support for the international VIMS team. We thank
K.D. Matz for data processing support and also K.P. Harrison and an
anonymous reviewer for their discussions.
NR 50
TC 54
Z9 54
U1 0
U2 5
PU ACADEMIC PRESS INC ELSEVIER SCIENCE
PI SAN DIEGO
PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA
SN 0019-1035
J9 ICARUS
JI Icarus
PD OCT
PY 2008
VL 197
IS 2
BP 526
EP 538
DI 10.1016/j.icarus.2008.06.002
PG 13
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 356OT
UT WOS:000259788200012
ER
PT J
AU Coustenis, A
Jennings, DE
Jolly, A
Benilan, Y
Nixon, CA
Vinatier, S
Gautier, D
Bjoraker, GL
Romani, PN
Carlson, RC
Flasar, FM
AF Coustenis, Athena
Jennings, Donald E.
Jolly, Antoine
Benilan, Yves
Nixon, Conor A.
Vinatier, Sandrine
Gautier, Daniel
Bjoraker, Gordon L.
Romani, Paul N.
Carlson, Ronald C.
Flasar, F. Michael
TI Detection of C2HD and the D/H ratio on Titan
SO ICARUS
LA English
DT Article
DE Titan; atmospheres, composition; infrared observations; satellites,
atmospheres; satellites, composition
ID COMPOSITE INFRARED SPECTROMETER; ATMOSPHERIC TEMPERATURES; CASSINI/CIRS;
HYDROCARBONS; SPECTRA; PHOTOCHEMISTRY; STRATOSPHERE; ABUNDANCE;
PROFILES; METHANE
AB We report here the first detection of mono-deuterated acetylene (acetylene-d1, C2HD) in Titan's atmosphere from the presence of two of its emission bands at 678 and 519 cm(-1) as observed in CIRS spectral averages of nadir and limb observations taken between July 2004 and mid-2007. By using new laboratory spectra for this molecule, we were able to derive its abundance at different locations over Titan's disk. We find the C2HD value (1.27(-0.22)(-0.13) x 10(-9)) to be roughly constant with latitude from the South to about 45 degrees N and then to increase slightly in the North, as is the case for C2H2. Fitting the 678 cm(-1) nu(5) band simultaneously with the nearby C2H2 729 cm(-1) nu(5) band, allows us to infer a D/H ratio in acetylene on Titan with an average of the modal values of 2.09 +/- 0.45 x 10(-4) from the nadir observations, the uncertainties being mainly due to the vertical profile used for the fit of the acetylene band. Although still subject to significant uncertainty, this D/H ratio appears to be significantly larger than the one derived in methane from the CH3D band (upper limit of 1.5 x 10(-4) : Bezard, B., Nixon, C.A., Kleiner, I., Jennings, D.E., 2007. Icarus, 191, 397-400; Coustenis, A., Achterberg, R., Conrath, B., Jennings, D., Marten, A., Gautier, D., Bjoraker, G., Nixon, C., Romani, P., Carlson, R., Flasar, M., Samuelson, R.E., Teanby, N., Irwin, P., 136zard, B., Orton, G., Kunde, V., Abbas, M., Courtin, R., Fouchet, Th., Hubert, A., Lellouch, E., Mondellini, J., Taylor, F.W., Vinatier, S., 2007. Icarus 189, 35-62). From the analysis of limb data we infer D/H values of 9.6(-3.1)(-4.5) x 10(-5) (at 54 degrees S), 2.4(-0.7)(-0-9) X 10(-4) (at 15 degrees S), 2.7(-0.6)(-0.7) X 10(-4) (at 54 degrees N) and 1.9(-0.5)(-0.7) X 10(-4) (at 80 degrees N), which average to a mean value of 1.63 +/- 0.27 x 10(-4). (C) 2008 Elsevier Inc. All rights reserved.
C1 [Coustenis, Athena; Vinatier, Sandrine; Gautier, Daniel] Observ Paris, LESIA, F-92195 Meudon, France.
[Jennings, Donald E.; Nixon, Conor A.; Bjoraker, Gordon L.; Romani, Paul N.; Carlson, Ronald C.; Flasar, F. Michael] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
[Jolly, Antoine; Benilan, Yves] Univ Paris 12, CNRS, LISA, F-94010 Creteil, France.
[Jolly, Antoine; Benilan, Yves] Univ Paris 07, F-94010 Creteil, France.
[Nixon, Conor A.] Univ Maryland, Dept Astron, College Pk, MD 20742 USA.
[Carlson, Ronald C.] Catholic Univ Amer, IACS, Greenbelt, MD 20771 USA.
RP Coustenis, A (reprint author), Observ Paris, LESIA, 5 Pl Jules Janssen, F-92195 Meudon, France.
EM athena.coustenis@obspm.fr
RI JOLLY, antoine/D-3238-2009; Nixon, Conor/A-8531-2009; Flasar, F
Michael/C-8509-2012; Romani, Paul/D-2729-2012; Bjoraker,
Gordon/D-5032-2012; Jennings, Donald/D-7978-2012
OI Nixon, Conor/0000-0001-9540-9121;
FU NASA
FX We thank Luciano Fusina, Filippo Tamassia and Gianfranco Di Lonardo from
the Dipartimento di Chimica Fisica e Inorganica of the University of
Bologna, Italy, for the laboratory infrared spectra which they kindly
sent us and which helped us with the line positions for C2HD.
We gratefully recognize the contribution and valuable help of a large
number of people including M. Segura, J. Brasunas, J. Mondelini, A.
Matmoukine, Emilie Royer, Laurette Piani and Zhi-Fang Xu in the CIRS
data preparation, archiving and processing. The US-based authors
acknowledge the support of NASA through the Cassini mission during the
period in which this work was performed. We have also received
constructive comments from two anonymous reviewers.
NR 27
TC 29
Z9 29
U1 0
U2 2
PU ACADEMIC PRESS INC ELSEVIER SCIENCE
PI SAN DIEGO
PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA
SN 0019-1035
J9 ICARUS
JI Icarus
PD OCT
PY 2008
VL 197
IS 2
BP 539
EP 548
DI 10.1016/j.icarus.2008.06.003
PG 10
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 356OT
UT WOS:000259788200013
ER
PT J
AU Achterberg, RK
Conrath, BJ
Gierasch, PJ
Flasar, FM
Nixon, CA
AF Achterberg, Richard K.
Conrath, Barney J.
Gierasch, Peter J.
Flasar, F. Michael
Nixon, Conor A.
TI Observation of a tilt of Titan's middle-atmospheric superrotation
SO ICARUS
LA English
DT Article
DE Titan; atmospheres, structure; atmospheres, dynamics; infrared
observations
ID COMPOSITE INFRARED SPECTROMETER; GENERAL-CIRCULATION MODEL;
TEMPERATURES; OCCULTATION; DYNAMICS; WINDS
AB Maps of isotherms on surfaces of constant pressure in Titan's middle atmosphere encircle the poles but show an offset, implying that the mean zonal flow has an axis of symmetry that is tilted relative to the spin axis of the solid body. The effect is seen in both hemispheres around a consistent axis. Periodogram analysis of the temperature field shows that wavenumber one, the signal corresponding to the spin tilt, is the strongest wave component. We conjecture that the tilt of the atmospheric spin is due to a feedback between the flow and the solar heating. The spin adjusts itself to align the spin equator with the direction toward the Sun, and thereby maximizes the efficiency with which the meridional circulation pumps angular momentum upward to generate superrotation. (C) 2008 Elsevier Inc. All rights reserved.
C1 [Achterberg, Richard K.; Flasar, F. Michael] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
[Achterberg, Richard K.; Nixon, Conor A.] Univ Maryland, Dept Astron, College Pk, MD 20742 USA.
[Conrath, Barney J.; Gierasch, Peter J.] Cornell Univ, Dept Astron, Ithaca, NY 14853 USA.
RP Achterberg, RK (reprint author), NASA, Goddard Space Flight Ctr, Code 693, Greenbelt, MD 20771 USA.
EM Richard.K.Achterberg@nasa.gov
RI Nixon, Conor/A-8531-2009; Flasar, F Michael/C-8509-2012
OI Nixon, Conor/0000-0001-9540-9121;
FU NASA
FX This work has been supported by the NASA Cassini Project.
NR 22
TC 27
Z9 27
U1 0
U2 0
PU ACADEMIC PRESS INC ELSEVIER SCIENCE
PI SAN DIEGO
PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA
SN 0019-1035
EI 1090-2643
J9 ICARUS
JI Icarus
PD OCT
PY 2008
VL 197
IS 2
BP 549
EP 555
DI 10.1016/j.icarus.2008.05.014
PG 7
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 356OT
UT WOS:000259788200014
ER
PT J
AU Meadows, VS
Orton, G
Line, M
Liang, MC
Yung, YL
Van Cleve, J
Burgdorf, MJ
AF Meadows, Victoria S.
Orton, Glenn
Line, Michael
Liang, Mao-Chang
Yung, Yuk L.
Van Cleve, Jeffrey
Burgdorf, Martin J.
TI First Spitzer observations of Neptune: Detection of new hydrocarbons
SO ICARUS
LA English
DT Article
DE Neptune, atmosphere; spectroscopy; infrared observations; atmospheres,
composition
ID SPITZER-SPACE-TELESCOPE; INFRARED-SPECTROSCOPY; ATMOSPHERIC COMPOSITION;
SATURNIAN SYSTEM; GIANT PLANETS; URANUS; OXYGEN; RATIO; CO
AB We present the first spectra of Neptune taken with the Spitzer Space Telescope, highlighting the high-sensitivity, moderate-resolution 10-20 mu m (500-1000 cm(-1)) spectra. We report the discovery of methylacetylene (CH3C2H) and diacetylene (C4H2) with derived 0.1-mbar volume mixing ratios of (1.2 +/- 0.1) x 10(-10) and (3 +/- 1) X 10(-12) respectively. (C) 2008 Elsevier Inc. All rights reserved.
C1 [Meadows, Victoria S.] CALTECH, Spitzer Sci Ctr, Pasadena, CA 91125 USA.
[Orton, Glenn] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[Line, Michael] Univ Wisconsin, Dept Astron, Madison, WI 53706 USA.
[Liang, Mao-Chang; Yung, Yuk L.] Calif Inst Technol Geol & Planetary Sci, Pasadena, CA 91125 USA.
[Van Cleve, Jeffrey] Ball Aerosp & Technologies Corp, Boulder, CO 80301 USA.
[Burgdorf, Martin J.] Liverpool John Moores Univ, Astrophys Res Inst, Birkenhead CH41 1LD, Merseyside, England.
RP Meadows, VS (reprint author), Univ Washington, Dept Astron, Box 351580, Seattle, WA 98195 USA.
EM vsm@astro.washington.edu
FU NASA [NAG5-13296]
FX This work is based on observations made with the Spitzer Space
Telescope, which is operated by the jet Propulsion Laboratory,
California Institute of Technology under a contract with NASA. M.C.L.
and Y.L.Y. were supported in part by NASA Grant NAG5-13296 to the
California Institute of Technology. We wish to thank Julianne Moses for
her model vertical constituent profiles in advance of publication-and
for several extremely helpful discussions. The IRS was a collaborative
venture between Cornell University and Ball Aerospace Corporation funded
by NASA through the jet Propulsion Laboratory and Ames Research Center.
NR 29
TC 15
Z9 15
U1 1
U2 2
PU ACADEMIC PRESS INC ELSEVIER SCIENCE
PI SAN DIEGO
PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA
SN 0019-1035
EI 1090-2643
J9 ICARUS
JI Icarus
PD OCT
PY 2008
VL 197
IS 2
BP 585
EP 589
DI 10.1016/j.icarus.2008.05.023
PG 5
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 356OT
UT WOS:000259788200018
ER
PT J
AU Starr, SO
AF Starr, Stanley O.
TI 50 Years of Electronic Checkout and Launch Systems at the Kennedy Space
Center
SO IEEE AEROSPACE AND ELECTRONIC SYSTEMS MAGAZINE
LA English
DT Article
AB When NASA was created in 1958 one of the elements incorporated into this new agency was the Army Ballistic Missile Agency (ABMA) in Huntsville, Alabama and its subordinate Missile Firing Laboratory (MFL) in Cape Canaveral. Under NASA, the MFL became the Launch Operations Directorate of the George C. Marshall Space Flight Center in Huntsville, but expanding operations in the build-up to Apollo dictated that it be given the status of a full-fledged center in July, 1962 [1]. The next year it was renamed the John F. Kennedy Space Center (KSC) after the president whose vision transformed its first decade of operation.
The ABMA was under the technical leadership of Dr. Wernher von Braun. The MFL was run by his deputy Dr. Kurt Debus, an electrical engineer whose experience in the field began in the early days of V-2 testing in war-time Germany. In 1952, a group led by Debus arrived in Cape Canaveral to begin, test launches of the new Redstone missile [2]. During the 1950s, the MFL built several launch complexes and tested the Redstone, Jupiter, and Jupiter C missiles. This small experienced team of engineers and technicians formed the seed from which has grown the KSC team of today.
This briefly reviews the evolution, successes, and setbacks of KSC electronic technologies for integration, checkout, and launch of space vehicles and payloads. We show that this very successful technology development was driven by greater vehicle complexity and heavily influenced and constrained by the commercial state-of-the-art in electronics.
C1 NASA, Canaveral Sect, Kennedy Space Ctr, FL 32899 USA.
RP Starr, SO (reprint author), NASA, Canaveral Sect, Kennedy Space Ctr, FL 32899 USA.
NR 6
TC 0
Z9 0
U1 1
U2 6
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA
SN 0885-8985
J9 IEEE AERO EL SYS MAG
JI IEEE Aerosp. Electron. Syst. Mag.
PD OCT
PY 2008
VL 23
IS 10
BP 4
EP 10
DI 10.1109/MAES.2008.4665318
PN 1
PG 7
WC Engineering, Aerospace; Engineering, Electrical & Electronic
SC Engineering
GA 363WM
UT WOS:000260298200001
ER
PT J
AU Wu, D
Hu, YX
McCormick, MP
Xu, KM
Liu, ZY
Smith, B
Omar, AH
Chang, FL
AF Wu, Dong
Hu, Yongxiang
McCormick, M. Patrick
Xu, Kuan-Man
Liu, Zhaoyan
Smith, Bill, Jr.
Omar, Ali H.
Chang, Fu-Lung
TI Deriving Marine-Boundary-Layer Lapse Rate from Collocated CALIPSO,
MODIS, and AMSR-E Data to Study Global Low-Cloud Height Statistics
SO IEEE GEOSCIENCE AND REMOTE SENSING LETTERS
LA English
DT Article
DE Marine boundary layer (MBL); temperature lapse rate
ID SATELLITE
AB Global cloud-top height statistics of marine-boundary-layer clouds are derived from the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) Level 2 aerosol and cloud layer products. The boundary-layer lapse rate in the northeast region of the Pacific Ocean is investigated using sea surface temperature (SST) data from the Advanced Microwave Scanning Radiometer-EOS (AMSR-E), cloud-top temperature data from the Moderate Resolution Imaging Spectroradiometer (MODIS), and cloud-top height data from CALIPSO. Based on the lapse rate derived from the combined CALIPSO/MODIS/AMSR-E measurements, cloud-top heights in regions within CALIPSO tracks are derived from AMSR SST and MODIS cloud temperature to test the validity of this approach. For homogeneous low-level clouds, the results agree with the cloud-top height from the collocated CALIPSO cloud-top height measurements. These results suggest that the database of derived lapse rates from the combined measurements can he applied to study cloud-top height climate statistics using the MODIS and AMSR data when CALIPSO observations are not available.
C1 [Wu, Dong] Ocean Univ China, Minist Educ China, Key Lab Ocean Remote Sensing, Qingdao 266003, Peoples R China.
[McCormick, M. Patrick] Hampton Univ, Dept Atmospher & Planetary Sci, Hampton, VA 23668 USA.
[Hu, Yongxiang; Xu, Kuan-Man; Liu, Zhaoyan; Smith, Bill, Jr.; Omar, Ali H.; Chang, Fu-Lung] NASA, Langley Res Ctr, Hampton, VA 23681 USA.
RP Wu, D (reprint author), Ocean Univ China, Minist Educ China, Key Lab Ocean Remote Sensing, Qingdao 266003, Peoples R China.
EM dongwu@orsi.ouc.edu.cn; yongxiang.hu-1@nasa.gov;
PAT.MCCORMICK@hampton.edu; kuan-man.xu@nasa.gov; zhaoyan.liu-1@nasa.gov;
william.l.smith@nasa.gov; ali.h.omar@nasa.gov; chang@larc.nasa.gov
RI Liu, Zhaoyan/A-9604-2009; Liu, Zhaoyan/B-1783-2010; Xu,
Kuan-Man/B-7557-2013; Hu, Yongxiang/K-4426-2012; Omar, Ali/D-7102-2017
OI Liu, Zhaoyan/0000-0003-4996-5738; Xu, Kuan-Man/0000-0001-7851-2629;
Omar, Ali/0000-0003-1871-9235
FU NASA; China Scholarship Council
FX This work was supported by the MIDAS project of NASA Radiation Science
Program. The work of Dong Wu was supported by the China Scholarship
Council.
NR 10
TC 7
Z9 7
U1 0
U2 7
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA
SN 1545-598X
J9 IEEE GEOSCI REMOTE S
JI IEEE Geosci. Remote Sens. Lett.
PD OCT
PY 2008
VL 5
IS 4
BP 649
EP 652
DI 10.1109/LGRS.2008.2002024
PG 4
WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote
Sensing; Imaging Science & Photographic Technology
SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science
& Photographic Technology
GA 373FO
UT WOS:000260956600020
ER
PT J
AU Xiong, XX
Sun, JQ
Barnes, W
AF Xiong, Xiaoxiong
Sun, Junqiang
Barnes, William
TI Intercomparison of On-Orbit Calibration Consistency Between Terra and
Aqua MODIS Reflective Solar Bands Using the Moon
SO IEEE GEOSCIENCE AND REMOTE SENSING LETTERS
LA English
DT Article
DE Aqua; calibration; Moderate Resolution Imaging Spectroradiometer
(MODIS); moon; reflective solar bands (RSBs); Terra
ID SPECTRAL IRRADIANCE; PERFORMANCE
AB Two nearly identical Moderate Resolution Imaging Spectroradiometer (MODIS) sensors, one on the Terra and the other on the Aqua satellite, are currently operating in space, making continuous global observations in 36 spectral bands: 20 reflective solar bands (RSBs) and 16 thermal emissive bands. For MODIS RSB with wavelengths from 0.41 to 2.1 mu m, the sensor-specified calibration-accuracy requirements are +/- 2% for reflectance and +/- 5% for radiance products. They are calibrated on-orbit by a solar diffuser (SD) and an SD stability monitor. In addition, lunar observations are scheduled regularly to monitor the RSB radiometric calibration stability. This letter describes an intercomparison method developed for evaluating the calibration consistency between Terra and Aqua MODIS RSBs and calibration differences among detectors in each spectral band. It presents intercomparison results derived from Terra and Aqua MODIS lunar observations made over their overlapped mission operation. This method uses predicted lunar irradiances derived from a lunar model to remove lunar-viewing-geometry differences among different observations made by each sensor. The results, excluding the bands which either have electronic crosstalk or saturate during lunar observations, show that the Terra and Aqua MODIS RSBs have been consistently calibrated to within +/- 1%. For the detectors within any one spectral band, the calibration differences are less than +/- 0.5%. The methodology developed here can be applied to other sensors for intercomparison studies.
C1 [Xiong, Xiaoxiong] NASA, Goddard Space Flight Ctr, Sci & Explorat Directorate, Greenbelt, MD 20771 USA.
[Sun, Junqiang] Sci Syst & Applicat Inc, Lanham, MD 20706 USA.
[Barnes, William] Univ Maryland, Joint Ctr Earth Syst Technol JCET, Baltimore, MD 21250 USA.
RP Xiong, XX (reprint author), NASA, Goddard Space Flight Ctr, Sci & Explorat Directorate, Greenbelt, MD 20771 USA.
EM Xiaoxiong.Xiong-1@nasa.gov; junqiang_sun@ssaihq.com; wlbarnes9@gvtc.com
NR 17
TC 29
Z9 29
U1 1
U2 6
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA
SN 1545-598X
J9 IEEE GEOSCI REMOTE S
JI IEEE Geosci. Remote Sens. Lett.
PD OCT
PY 2008
VL 5
IS 4
BP 778
EP 782
DI 10.1109/LGRS.2008.2005591
PG 5
WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote
Sensing; Imaging Science & Photographic Technology
SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science
& Photographic Technology
GA 373FO
UT WOS:000260956600047
ER
PT J
AU Cattivelli, FS
Estabrook, P
Satorius, EH
Sayed, AH
AF Cattivelli, Federico S.
Estabrook, Polly
Satorius, Edgar H.
Sayed, Ali H.
TI Carrier Recovery Enhancement for Maximum-Likelihood Doppler Shift
Estimation in Mars Exploration Missions
SO IEEE JOURNAL OF SELECTED TOPICS IN SIGNAL PROCESSING
LA English
DT Article
DE Doppler effect; frequency estimation; maximum-likelihood estimation;
space vehicle communication
ID PARAMETER-ESTIMATION; CHIRP SIGNALS
AB One of the most crucial stages of the Mars Exploration Missions is the Entry, Descent, and Landing (EDL) phase. During EDL, maintaining reliable communication from the spacecraft to Earth is extremely important for the success of future missions, especially in case of mission failure. EDL is characterized by very deep accelerations, caused by friction, parachute deployment and rocket firing among others. These dynamics cause a severe Doppler shift on the carrier communications link to Earth. Methods have been proposed to estimate the Doppler shift based on Maximum Likelihood. So far these methods have proved successful, but it is expected that the next Mars mission, known as the Mars Science Laboratory, will suffer from higher dynamics and lower SNR. Thus, improving the existing estimation methods becomes a necessity. We propose a Maximum Likelihood approach that takes into account the power in the data tones to enhance carrier recovery, and improve the estimation performance by up to 3 dB. Simulations are performed using real data obtained during the EDL stage of the Mars Exploration Rover B (MERB) mission.
C1 [Cattivelli, Federico S.; Sayed, Ali H.] Univ Calif Los Angeles, Dept Elect Engn, Los Angeles, CA 90095 USA.
[Estabrook, Polly; Satorius, Edgar H.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Cattivelli, FS (reprint author), Univ Calif Los Angeles, Dept Elect Engn, Los Angeles, CA 90095 USA.
EM fcattiv@ee.ucla.edu; Polly.Estabrook@jpl.nasa.gov;
satorius@jpl.nasa.gov; sayed@ee.ucla.edu
RI Sayed, Ali/D-6251-2012
OI Sayed, Ali/0000-0002-5125-5519
FU Jet Propulsion Laboratory [1276256]; National Science Foundation (NSF)
[ECS-0601266, ECS-0725441]
FX This work was supported by a Grant from the Jet Propulsion Laboratory
under award 1276256 and by National Science Foundation (NSF) awards
ECS-0601266 and ECS-0725441. The associate editor coordinating the
review of this manuscript and approving it for publication was Prof.
Alle-Jan van der Veen.
NR 21
TC 2
Z9 2
U1 0
U2 3
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA
SN 1932-4553
J9 IEEE J-STSP
JI IEEE J. Sel. Top. Signal Process.
PD OCT
PY 2008
VL 2
IS 5
BP 658
EP 669
DI 10.1109/JSTSP.2008.2005289
PG 12
WC Engineering, Electrical & Electronic
SC Engineering
GA 437NZ
UT WOS:000265495500006
ER
PT J
AU Savtchenko, A
Kummerer, R
Smith, P
Gopalan, A
Kempler, S
Leptoukh, G
AF Savtchenko, Andrey
Kummerer, Robert
Smith, Peter
Gopalan, Arun
Kempler, Steven
Leptoukh, Gregory
TI A-Train Data Depot: Bringing Atmospheric Measurements Together
SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING
LA English
DT Article; Proceedings Paper
CT IEEE International Geoscience and Remote Sensing Symposium (IGARSS)
CY JUL 23-27, 2007
CL Barcelona, SPAIN
SP IEEE
DE Aerosols; atmospheric measurements; clouds; data conversion; data
management; data security; optical scattering; precipitation; radar
scattering; remote sensing; satellite applications; temperature
measurement
ID CLOUDSAT MISSION; PRECIPITATION; SPACE
AB This paper describes the satellite data processing and services that constitute current functionalities of the A-Train Data Depot. We first provide a brief introduction to the original geometrical intricacies of the platforms and instruments of the A-Train constellation and then proceed with a description of our A-Train collocation-processing algorithm that provides subsets that facilitate synergistic use of the various instruments. Finally, we present some sample image products from our web-based Giovanni tool which allows users to display, compare, and download coregistered A-Train-related data.
C1 [Savtchenko, Andrey; Kummerer, Robert; Smith, Peter; Gopalan, Arun; Kempler, Steven; Leptoukh, Gregory] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
RP Savtchenko, A (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
EM Andrey.K.Savtchenko@nasa.gov
NR 7
TC 13
Z9 13
U1 0
U2 6
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA
SN 0196-2892
J9 IEEE T GEOSCI REMOTE
JI IEEE Trans. Geosci. Remote Sensing
PD OCT
PY 2008
VL 46
IS 10
BP 2788
EP 2795
DI 10.1109/TGRS.2008.917600
PN 1
PG 8
WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote
Sensing; Imaging Science & Photographic Technology
SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science
& Photographic Technology
GA 359PJ
UT WOS:000260000300003
ER
PT J
AU Anagnostou, MN
Nystuen, JA
Anagnostou, EN
Nikolopoulos, EI
Amitai, E
AF Anagnostou, Marios N.
Nystuen, Jeffrey A.
Anagnostou, Emmanouil N.
Nikolopoulos, Efthymios I.
Amitai, Eyal
TI Evaluation of Underwater Rainfall Measurements During the Ionian Sea
Rainfall Experiment
SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING
LA English
DT Article; Proceedings Paper
CT IEEE International Geoscience and Remote Sensing Symposium (IGARSS)
CY JUL 23-27, 2007
CL Barcelona, SPAIN
SP IEEE
DE Radar measurements; rainfall; sound level; underwater acoustical
measurements; X-band dual-polarization (XPOL) radar
ID X-BAND; POLARIMETRIC RADAR; ATTENUATION; NOISE
AB Rainfall on the sea surface generates a loud and distinctive sound underwater. This sound propagates downward and attenuates, producing an effective listening area or an equivalent "catchment basin" for a listening device that is a function of depth and frequency. Acoustical measurements of rainfall are reported from four passive aquatic listeners (PALs) at 60-, 200-, 1000-, and 2000-m depths from a mooring in the Ionian Sea off the southwestern coast of Greece (37N, 21.5E) from January to April 2004. These measurements are compared to colocated high-resolution X-band dual-polarization (XPOL) radar rainfall measurements. The XPOL radar reports the spatial distribution of rainfall variability over the listening areas of the PALs. Four quality-controlled rainfall events, including drizzle, squall line, and heavy rainfall, are presented in this study. The radar rainfall is spatially averaged over the mooring and compared with the four different acoustic measurements at different depths. To understand the issue of spatial averaging, quantitative comparisons are presented, showing a high correlation between the acoustic measurements and the area-averaged radar estimates at corresponding resolutions.
C1 [Anagnostou, Marios N.; Anagnostou, Emmanouil N.; Nikolopoulos, Efthymios I.] Hellen Ctr Marine Res, Inst Inland Waters, Anavissos 19013, Greece.
[Nystuen, Jeffrey A.] Univ Washington, Appl Phys Lab, Seattle, WA 98105 USA.
[Anagnostou, Emmanouil N.; Nikolopoulos, Efthymios I.] Univ Connecticut, Dept Civil & Environm Engn, Storrs, CT 06269 USA.
[Amitai, Eyal] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
[Amitai, Eyal] Chapman Univ, Orange, CA 92866 USA.
RP Anagnostou, MN (reprint author), Hellen Ctr Marine Res, Inst Inland Waters, Anavissos 19013, Greece.
EM managnostou@ath.hcmr.gr
RI Nikolopoulos, Efthymios/B-1717-2013
OI Nikolopoulos, Efthymios/0000-0002-5206-1249
NR 16
TC 5
Z9 5
U1 1
U2 9
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA
SN 0196-2892
J9 IEEE T GEOSCI REMOTE
JI IEEE Trans. Geosci. Remote Sensing
PD OCT
PY 2008
VL 46
IS 10
BP 2936
EP 2946
DI 10.1109/TGRS.2008.2000756
PN 1
PG 11
WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote
Sensing; Imaging Science & Photographic Technology
SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science
& Photographic Technology
GA 359PJ
UT WOS:000260000300019
ER
PT J
AU Georgieva, EM
Heaps, WS
Wilson, EL
AF Georgieva, Elena M.
Heaps, William S.
Wilson, Emily L.
TI Differential Radiometers Using Fabry-Perot Interferometric Technique for
Remote Sensing of Greenhouse Gases
SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING
LA English
DT Article; Proceedings Paper
CT IEEE International Geoscience and Remote Sensing Symposium (IGARSS)
CY JUL 23-27, 2007
CL Barcelona, SPAIN
SP IEEE
DE Absorbing media; atmospheric measurements; Fabry-Perot (FP)
interferometers; optical interferometry; remote sensing
ID FUTURE PERFORMANCE; ABSORPTION LIDAR; CARBON; MISSION; CLIMATE; CO2;
CLOUDINESS; AEROSOLS; COLUMN
AB A new type of remote-sensing radiometer based upon the Fabry-Perot (FP) interferometric technique has been developed at NASA's Goddard Space Flight Center and tested from both ground and aircraft platforms. The sensor uses direct or reflected sunlight and has channels for measuring the column concentration of carbon dioxide at 1570 nm, oxygen lines sensitive to pressure and temperature at 762 and 768 nm, and water vapor (940 nm). A solid FP etalon is used as a tunable narrow bandpass filter to restrict the measurement to the gas of interest's absorption bands. By adjusting the temperature of the etalon, which changes the index of refraction of its material, the transmission fringes can be brought into nearly exact correspondence with the absorption lines of the particular species. With this alignment between absorption lines and fringes, changes in the amount of a species in the atmosphere strongly affect the amount of light transmitted by the etalon and can be related to gas concentration. The technique is applicable to different chemical species. We have performed simulations and instrument design studies for CH4, (CO2)-C-13 isotope, and CO detection.
C1 [Georgieva, Elena M.] Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21228 USA.
[Heaps, William S.] NASA, Goddard Space Flight Ctr, Instrument Syst & Technol Div, Greenbelt, MD 20771 USA.
[Wilson, Emily L.] NASA, Goddard Space Flight Ctr, Laser & Electroopt Branch, Greenbelt, MD 20771 USA.
RP Georgieva, EM (reprint author), Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21228 USA.
RI Wilson, Emily/C-9158-2012
OI Wilson, Emily/0000-0001-5634-3713
NR 32
TC 3
Z9 7
U1 2
U2 14
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA
SN 0196-2892
J9 IEEE T GEOSCI REMOTE
JI IEEE Trans. Geosci. Remote Sensing
PD OCT
PY 2008
VL 46
IS 10
BP 3115
EP 3122
DI 10.1109/TGRS.2008.921570
PN 2
PG 8
WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote
Sensing; Imaging Science & Photographic Technology
SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science
& Photographic Technology
GA 359PK
UT WOS:000260000400006
ER
PT J
AU Dinnat, EP
Le Vine, DM
AF Dinnat, Emmanuel P.
Le Vine, David M.
TI Impact of Sun Glint on Salinity Remote Sensing: An Example With the
Aquarius Radiometer
SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING
LA English
DT Article; Proceedings Paper
CT IEEE International Geoscience and Remote Sensing Symposium (IGARSS)
CY JUL 23-27, 2007
CL Barcelona, SPAIN
SP IEEE
DE Aquarius; L-band; radiometry; sea surface salinity (SSS); Sun glint
ID SEA-SURFACE SALINITY; L-BAND; BRIGHTNESS TEMPERATURES; ATMOSPHERIC
STABILITY; FIELD EXPERIMENTS; OCEAN SURFACE; SCATTERING; SLOPE; MODEL;
ALTIMETERS
AB The Aquarius/SAC-D mission will employ three L-band (1.41 GHz) radiometers dedicated to the remote sensing of sea surface salinity. The radiation from the Sun reflected at the ocean surface toward the radiometer is an important source of interference for retrieving salinity; in fact, the mission will be in a dawn/dusk Sun-synchronous orbit with the beams oriented toward the night side of the orbit in order to limit this signal. In this paper, the effect of ocean surface roughness on the reflected radiation is examined. The reflected Sun radiation can be separated into two components: 1) a quasi-specular component and 2) a scattered component, due largely to small-scale roughness. We show that the first component has a large brightness temperature but, in the Aquarius geometry, is located far from the antenna boresight. The scattered component has relatively small brightness temperature but can extend to the antenna boresight where the gain is maximum. This can occur at high latitude near the summer solstice when the antenna footprint is not in shadow and can cause significant contamination. While the calculations have been done for the specific geometry of the Aquarius instrument, the conclusions drawn regarding the effect of roughness on the reflected solar radiation are characteristic of remote sensing at L-band.
C1 [Dinnat, Emmanuel P.] Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21250 USA.
[Le Vine, David M.] NASA, Goddard Space Flight Ctr, Hydrospher & Biospher Sci Lab, Instrumentat Sci Branch, Greenbelt, MD 20771 USA.
RP Dinnat, EP (reprint author), Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21250 USA.
RI Dinnat, Emmanuel/D-7064-2012
OI Dinnat, Emmanuel/0000-0001-9003-1182
NR 35
TC 18
Z9 20
U1 0
U2 6
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA
SN 0196-2892
J9 IEEE T GEOSCI REMOTE
JI IEEE Trans. Geosci. Remote Sensing
PD OCT
PY 2008
VL 46
IS 10
BP 3137
EP 3150
DI 10.1109/TGRS.2008.2000629
PN 2
PG 14
WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote
Sensing; Imaging Science & Photographic Technology
SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science
& Photographic Technology
GA 359PK
UT WOS:000260000400009
ER
PT J
AU Hudson, D
Long, DG
AF Hudson, Derek
Long, David G.
TI Optimal Estimation of Calibration Parameters in Polarimetric Microwave
Radiometers
SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING
LA English
DT Article
DE Polarimetric radiometer; radiometer calibration; Stokes parameters
AB Methods for internal calibration of a certain class of microwave polarimetric radiometers are presented by Piepmeier. In that work, the calibration parameters are estimated algebraically. We demonstrate that Bayesian estimation decreases the root-mean-square error of the estimates by a factor of two. This improvement is obtained by using knowledge of the noise structure of the measurements and by utilizing all of the information provided by the measurements. Drawbacks are the increased complexity of the method and an increase in computation. We also extend the method to estimate several hardware component parameters of interest in system calibration.
C1 [Hudson, Derek; Long, David G.] Brigham Young Univ, Dept Elect & Comp Engn, Provo, UT 84602 USA.
[Hudson, Derek] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
RP Hudson, D (reprint author), Brigham Young Univ, Dept Elect & Comp Engn, Provo, UT 84602 USA.
EM Derek.L.Hudson@nasa.gov; long@ee.byu.edu
RI Long, David/K-4908-2015
OI Long, David/0000-0002-1852-3972
FU NASA Goddard Space Flight Center
FX Manuscript received April 10. 2007: revised November 21, 2007. Current
version published October 1. 2008. This work was supported by the NASA
Goddard Space Flight Center.
NR 8
TC 0
Z9 0
U1 0
U2 2
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA
SN 0196-2892
J9 IEEE T GEOSCI REMOTE
JI IEEE Trans. Geosci. Remote Sensing
PD OCT
PY 2008
VL 46
IS 10
BP 3223
EP 3237
DI 10.1109/TGRS.2008.921636
PN 2
PG 15
WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote
Sensing; Imaging Science & Photographic Technology
SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science
& Photographic Technology
GA 359PK
UT WOS:000260000400016
ER
PT J
AU Helder, DL
Markham, BL
Thome, KJ
Barsi, JA
Chander, G
Malla, R
AF Helder, Dennis L.
Markham, Brian L.
Thome, Kurtis J.
Barsi, Julia A.
Chander, Gyanesh
Malla, Rimy
TI Updated Radiometric Calibration for the Landsat-5 Thematic Mapper
Reflective Bands
SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING
LA English
DT Article
DE Absolute calibration; Landsat; pseudoinvariant site; radiometry;
Thematic Mapper (TM)
ID CROSS-CALIBRATION; SENSORS; PERFORMANCE; TARGETS; SITES; ETM+
AB The Landsat-5 Thematic Mapper (TM) has been the workhorse of the Landsat system. Launched in 1984, it continues collecting data through the time frame of this paper. Thus, it provides an invaluable link to the past history of the land features of the Earth's surface, and it becomes imperative to provide an accurate radiometric calibration of the reflective bands to the user community. Previous calibration has been based on information obtained from prelaunch, the onboard calibrator, vicarious calibration attempts, and cross-calibration with Landsat-7. Currently, additional data sources are available to improve this calibration. Specifically, improvements in vicarious calibration methods and development of the use of pseudoinvariant sites for trending provide two additional independent calibration sources. The use of these additional estimates has resulted in a consistent calibration approach that ties together all of the available calibration data sources. Results from this analysis indicate a simple exponential, or a constant model may be used for all bands throughout the lifetime of Landsat-5 TM. Where previously time constants for the exponential models were approximately one year, the updated model has significantly longer time constants in bands 1-3. In contrast, bands 4, 5, and 7 are shown to be best modeled by a constant. The models proposed in this paper indicate calibration knowledge of 5 % or better early in life, decreasing to nearly 2 % later in life. These models have been implemented at the U.S. Geological Survey Earth Resources Observation and Science (EROS) and are the default calibration used for all Landsat TM data now distributed through EROS.
C1 [Helder, Dennis L.] S Dakota State Univ, Dept Elect Engn & Comp Sci, Brookings, SD 57007 USA.
[Markham, Brian L.] NASA, Goddard Space Flight Ctr, Landsat Project Sci Off, Greenbelt, MD 20771 USA.
[Thome, Kurtis J.] Univ Arizona, Ctr Opt Sci, Remote Sensing Grp, Tucson, AZ 85721 USA.
[Barsi, Julia A.] NASA, Goddard Space Flight Ctr, Sci Syst & Applicat Inc, Greenbelt, MD 20771 USA.
[Chander, Gyanesh] US Geol Survey, Sci Applicat Int Corp, Ctr Earth Resources Observat & Sci, Sioux Falls, SD 57198 USA.
[Malla, Rimy] S Dakota State Univ, Image Proc Lab, Brookings, SD 57007 USA.
RP Helder, DL (reprint author), S Dakota State Univ, Dept Elect Engn & Comp Sci, Brookings, SD 57007 USA.
EM Dennis.Helder@sdstate.edu; Brian.L.Markham@nasa.gov;
kurt.thome@opt-sci.arizona.edu; Barsi@gsfc.nasa.gov; gchander@usgs.gov;
Rimy.Malla@sdstate.edu
RI Thome, Kurtis/D-7251-2012; Markham, Brian/M-4842-2013
OI Markham, Brian/0000-0002-9612-8169
FU Landsat Project Science Office at the Goddard Space Flight Center
[NNG05GB83G]; U.S. Geological Survey [03CRCN0001]
FX Manuscript received August 17. 2007; revised December 17, 2007. Current
version published October 1. 2008. This work was supported by the
Landsat Project Science Office at the Goddard Space Flight Center under
NASA Grant NNG05GB83G. The work of G. Chander was supported by the U.S.
Geological Survey under Contract 03CRCN0001.
NR 28
TC 33
Z9 35
U1 2
U2 7
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA
SN 0196-2892
J9 IEEE T GEOSCI REMOTE
JI IEEE Trans. Geosci. Remote Sensing
PD OCT
PY 2008
VL 46
IS 10
BP 3309
EP 3325
DI 10.1109/TGRS.2008.920966
PN 2
PG 17
WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote
Sensing; Imaging Science & Photographic Technology
SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science
& Photographic Technology
GA 359PK
UT WOS:000260000400023
ER
PT J
AU Angrisani, L
Lo Moriello, RS
D'Arco, M
Greenhall, CA
AF Angrisani, Leopoldo
Lo Moriello, Rosario Schiano
D'Arco, Mauro
Greenhall, Charles A.
TI A digital signal processing instrument for real-time phase noise
measurement
SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT
LA English
DT Article
DE data acquisition board; digital signal processor; phase noise
measurement; power spectrum (PS) evaluation; quadrature demodulation;
real-time measurement; seamless acquisition
AB A digital-signal-processing-based instrument for phase noise measurement on sinusoidal signals is described. It incorporates a special hardware architecture, which is made up of a core digital signal processor that is connected to a data acquisition board, and takes advantage of a new measurement procedure based on a quadrature demodulation scheme, which has been proposed by the authors. Thanks to an optimized implementation of this procedure, the instrument exploits all its hardware resources to achieve high performance and real-time operation. For input frequencies of up to some hundreds of kilohertz, the instrument proves to be capable both of updating phase noise power spectrum while seamlessly capturing the analyzed signal into its memory and of granting frequency resolution as good as a few units of hertz.
C1 [Angrisani, Leopoldo; Lo Moriello, Rosario Schiano] Univ Naples Federico 2, Dipartimento Informat & Sistemist, I-80125 Naples, Italy.
[D'Arco, Mauro] Univ Naples Federico 2, Dipartimento Ingn Elettr, I-80125 Naples, Italy.
[Greenhall, Charles A.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Angrisani, L (reprint author), Univ Naples Federico 2, Dipartimento Informat & Sistemist, I-80125 Naples, Italy.
EM angrisan@unina.it; rschiano@unina.it; darco@unina.it;
cgreenhall@jpl.nasa.gov
OI D'Arco, Mauro/0000-0003-1641-8359
FU National Aeronautics and Space Administration
FX The work of C. Greenhall was supported by a contract from the National
Aeronautics and Space Administration.
NR 18
TC 4
Z9 4
U1 0
U2 8
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA
SN 0018-9456
J9 IEEE T INSTRUM MEAS
JI IEEE Trans. Instrum. Meas.
PD OCT
PY 2008
VL 57
IS 10
BP 2098
EP 2107
DI 10.1109/TIM.2008.922102
PG 10
WC Engineering, Electrical & Electronic; Instruments & Instrumentation
SC Engineering; Instruments & Instrumentation
GA 353BM
UT WOS:000259541100001
ER
PT J
AU Li, W
Leung, H
Kwan, C
Linnell, BR
AF Li, Winston
Leung, Henry
Kwan, Chiman
Linnell, Bruce R.
TI E-nose vapor identification based on Dempster-Shafer fusion of multiple
classifiers
SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT
LA English
DT Article
DE Dempster-Shafer (DS); electronic nose (e-nose); k-nearest neighbor
(KNN); neural network (NN); Parzen classifier; support vector machine
(SVM); wavelet denoising
ID ELECTRONIC NOSE; FEATURE-EXTRACTION; CLASSIFICATION; SENSORS; ARRAY
AB Electronic noses (e-noses) are commonly used to monitor air contaminants in space stations and shuttles. Data preprocessing (measurement denoising and feature extraction) and pattern classification are important problems of an e-nose system. In this paper, the application of a wavelet-based denoising method and a Dempster-Shafer(DS) classification fusion method in an e-nose system are proposed. Six transient-state features are extracted from the sensor measurements filtered by the wavelet denoising method and are used to train multiple classifiers such as multilayer perceptrons (MLPs), support vector machines (SVMs), k-nearest neighbors (KNNs), and the Parzen classifier. The DS technique is used at the end to fuse the results of the multiple classifiers to get the final classification. Experimental analysis based on real vapor data shows that the wavelet denoising method can successfully remove both random noise and outliers, and the classification rate can be improved by using classifier fusion.
C1 [Li, Winston; Leung, Henry] Univ Calgary, Dept Elect & Comp Engn, Calgary, AB T2N 1N4, Canada.
[Kwan, Chiman] Signal Proc Inc, Rockville, MD 20850 USA.
[Linnell, Bruce R.] NASA, Kennedy Space Ctr, Appl Chem Lab, Orlando, FL 32899 USA.
RP Li, W (reprint author), Univ Calgary, Dept Elect & Comp Engn, Calgary, AB T2N 1N4, Canada.
EM leungh@ucalgary.ca
NR 25
TC 5
Z9 5
U1 1
U2 9
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA
SN 0018-9456
J9 IEEE T INSTRUM MEAS
JI IEEE Trans. Instrum. Meas.
PD OCT
PY 2008
VL 57
IS 10
BP 2273
EP 2282
DI 10.1109/TIM.2008.922092
PG 10
WC Engineering, Electrical & Electronic; Instruments & Instrumentation
SC Engineering; Instruments & Instrumentation
GA 353BM
UT WOS:000259541100019
ER
PT J
AU Edmonds, LD
Edmonds, KJ
AF Edmonds, Larry D.
Edmonds, Kevin J.
TI A Method for Estimating SEU Rates From Protons by Direct Ionization
SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE
LA English
DT Article
DE Direct ionization; path-length distribution; proton radiation effects
ID OPTOCOUPLERS; TRANSIENTS; UPSET
AB Protons that produce significant direct ionization in a sensitive volume also slow down, so the LET is not constant in large sensitive volumes. A single-event cross section for energy deposition within the volume that takes this into account is calculated analytically. It is up to the user to select a critical energy and a sensitive volume that gives the best representation of the charge-collection physics for the purpose of calculating SEU rates from protons by direct ionization for the device of interest. A complete set of equations is given only for an ellipsoidal sensitive volume, but other geometries could be treated once the required analytical functions have been provided. An example that utilizes the ellipsoidal sensitive volume is considered and is compared to measured cross sections.
C1 [Edmonds, Larry D.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[Edmonds, Kevin J.] Univ Calif Irvine, Irvine, CA 92697 USA.
RP Edmonds, LD (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM larry.d.edmonds@jpl.nasa.gov; kedmonds@uci.edu
NR 6
TC 5
Z9 7
U1 1
U2 4
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA
SN 0018-9499
J9 IEEE T NUCL SCI
JI IEEE Trans. Nucl. Sci.
PD OCT
PY 2008
VL 55
IS 5
BP 2666
EP 2678
DI 10.1109/TNS.2008.2002203
PG 13
WC Engineering, Electrical & Electronic; Nuclear Science & Technology
SC Engineering; Nuclear Science & Technology
GA 388JJ
UT WOS:000262015800014
ER
PT J
AU Hofer, RR
Johnson, LK
Goebel, DM
Wirz, RE
AF Hofer, Richard R.
Johnson, Lee K.
Goebel, Dan M.
Wirz, Richard E.
TI Effects of Internally Mounted Cathodes on Hall Thruster Plume Properties
SO IEEE TRANSACTIONS ON PLASMA SCIENCE
LA English
DT Article
DE Hall thrusters; hollow cathodes; plasma propulsion
ID PLASMA THRUSTERS; MAGNETIC-FIELD
AB The effects of cathode position on the operation and plume properties of an 8-kW Hall thruster are discussed. Thruster operation was investigated at operating conditions ranging from 200 to 500 V of discharge voltage, 10-40 A of discharge current, and 2-8 kW of discharge power, with a cathode positioned either in the traditional externally mounted configuration outside the outer magnetic pole piece or in an internally mounted configuration central to the inner magnetic core. With the external cathode, substantial emission in the visible spectrum that follows magnetic field lines surrounds the exterior pole pieces of the thruster. With the internal cathode, the emission is largely absent while the cathode plume is compressed and elongated in the axial direction by the strong axial magnetic field on the thruster centerline. Discharge current oscillation and ion species fraction measurements were found to be similar for the cathode locations, whereas the operation with the internal cathode was found to favor an improved coupling of the cathode plume with the thruster discharge. Ion current density measurements show that with respect to externally mounted designs, internally mounted cathodes reduce plume divergence and increase the symmetry of the near-field plume. The impacts of internally mounted cathodes on thruster physics and spacecraft integration activities are assessed.
C1 [Hofer, Richard R.; Johnson, Lee K.; Goebel, Dan M.; Wirz, Richard E.] CALTECH, Jet Prop Lab, Elect Prop Grp, Prop & Mat Engn Sect, Pasadena, CA 91109 USA.
RP Hofer, RR (reprint author), CALTECH, Jet Prop Lab, Elect Prop Grp, Prop & Mat Engn Sect, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM richard.r.hofer@jpl.nasa.gov
NR 31
TC 7
Z9 7
U1 3
U2 10
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA
SN 0093-3813
J9 IEEE T PLASMA SCI
JI IEEE Trans. Plasma Sci.
PD OCT
PY 2008
VL 36
IS 5
BP 2004
EP 2014
DI 10.1109/TPS.2008.2000962
PN 1
PG 11
WC Physics, Fluids & Plasmas
SC Physics
GA 378ZG
UT WOS:000261363100006
ER
PT J
AU Katz, I
Hofer, RR
Goebel, DM
AF Katz, Ira
Hofer, Richard R.
Goebel, Dan M.
TI Ion Current in Hall Thrusters
SO IEEE TRANSACTIONS ON PLASMA SCIENCE
LA English
DT Article
DE Electron transport; Hall thrusters; particle simulations; plasma
propulsion
ID STATIONARY PLASMA THRUSTER; PLUME; MODEL; DISCHARGE
AB To match the observed thrust and discharge current in Hall thrusters, computer simulations have typically assumed anomalous electron transport mechanisms, such as Bohm diffusion, to enhance electron mobility across magnetic field lines. Without enhanced electron transport, the simulations predict a much lower discharge current than observed, and too much of the potential drop is downstream of the channel exit. Rather than search for mechanisms to increase the electron scattering frequency, We seek to identify mechanisms that would increase the fraction of the current carried by ions, thus reducing the required electron current. We describe two mechanisms that enhance the current carried by ions. The first mechanism increases the ion current carried in the channel by simply including the effects of multiply charged ions on the plasma response. The importance of using accurate ionization cross sections and the need to include multiply charged ions even for discharge voltages of 300 V are discussed. The second mechanism is a process we term "ion reflux." In this process, current is carried by ions generated downstream of the channel exit. Portions of these ions impact the center of the thruster and are neutralized by cathode electrons. A large fraction of the resultant neutral atoms are reionized as they pass through the main exhaust beam. These newly born ions then carry additional current through the plume. Since neutrals freely move across magnetic field lines, ion reflux effectively enhances the cross-field electron transport. This second mechanism operates downstream of the exit plane and does not enhance electron transport in the acceleration region. Both of these mechanisms, i.e., multiply charged ions and ion reflux, reduce the need to invoke anomalous electron transport mechanisms in Hall thruster computer simulations. However, to date, no Hall thruster simulation has produced results in agreement with data without assuming some anomalous electron transport.
C1 [Katz, Ira; Hofer, Richard R.; Goebel, Dan M.] CALTECH, Jet Prop Lab, Elect Prop Grp, Prop & Mat Engn Sect, Pasadena, CA 91109 USA.
RP Katz, I (reprint author), CALTECH, Jet Prop Lab, Elect Prop Grp, Prop & Mat Engn Sect, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM ira.katz@jpl.nasa.gov; richard.r.hofer@jpl.nasa.gov
NR 36
TC 5
Z9 5
U1 2
U2 4
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA
SN 0093-3813
J9 IEEE T PLASMA SCI
JI IEEE Trans. Plasma Sci.
PD OCT
PY 2008
VL 36
IS 5
BP 2015
EP 2024
DI 10.1109/TPS.2008.2004219
PN 1
PG 10
WC Physics, Fluids & Plasmas
SC Physics
GA 378ZG
UT WOS:000261363100007
ER
PT J
AU Goebel, DM
AF Goebel, Dan M.
TI Analytical Discharge Model for RF Ion Thrusters
SO IEEE TRANSACTIONS ON PLASMA SCIENCE
LA English
DT Article
DE Gas discharges; ion engines; plasma generation
ID ELECTRON-IMPACT IONIZATION; CROSS-SECTIONS; BREAKDOWN; THRESHOLD; LENGTH
AB A comprehensive 0-D model of the plasma discharge in magnetic ring-cusp ion thrusters was previously developed. The model utilizes conservation of particles into and out of the ion thruster and conservation of energy into the discharge and out of the plasma, and provided the first closed solution for predicting ion-thruster discharge chamber performance. The 0-D discharge model was benchmarked against the performance measured on several ion thrusters, and successfully predicts the discharge loss as a function of mass utilization efficiency. The analytical model has been modified to handle the discharge chamber configurations and the different magnetic confinement physics found in RF ion thrusters. In these ion thrusters, there is no applied magnetic field to provide confinement of the electrons and ions, but the ac magnetic field induced by the inductively coupled RF coil affects the particle confinement and transport and is important in determining the discharge loss and thruster performance. The modifications to the model required to address the physics of RF thrusters will be discussed, and results showing the predicted ion thruster performance will be presented.
C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Goebel, DM (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM dan.m.goebel@jpl.nasa.gov
NR 28
TC 11
Z9 11
U1 1
U2 6
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA
SN 0093-3813
J9 IEEE T PLASMA SCI
JI IEEE Trans. Plasma Sci.
PD OCT
PY 2008
VL 36
IS 5
BP 2111
EP 2121
DI 10.1109/TPS.2008.2004232
PN 1
PG 11
WC Physics, Fluids & Plasmas
SC Physics
GA 378ZG
UT WOS:000261363100016
ER
PT J
AU Wirz, RE
Anderson, JR
Goebel, DM
Katz, I
AF Wirz, Richard E.
Anderson, John R.
Goebel, Dan M.
Katz, Ira
TI Decel Grid Effects on Ion Thruster Grid Erosion
SO IEEE TRANSACTIONS ON PLASMA SCIENCE
LA English
DT Article
DE Decel grid; grid erosion; ion thruster; Xenon Ion Propulsion System
(XIPS)
AB Jet Propulsion Laboratory (JPL) is currently assessing the applicability of the 25-cm Xenon Ion Propulsion System (XIPS) as part of an effort to infuse low-cost technically mature commercial ion thruster systems into NASA deep space missions. Since these mission require extremely long thruster lifetimes to attain the required mission Delta V, this paper is focused on understanding the dominate wear mechanisms that effect the life of the XIPS three-grid system. Analysis of the XIPS three-grid configuration with JPL's CEX3D grid erosion model shows that the third "decel" grid effectively protects the accel grid from pits and grooves erosion that is commonly seen with two-grid ion thruster grid systems. For a three-grid system, many of the charge-exchange ions created downstream of the grid plane will impact the decel grid at relatively low energies (similar to 25 V), instead of impacting the accel grid at high energies (similar to 200 V), thus reducing overall erosion. JPL's CEX3D accurately predicts the erosion patterns for the accel grid, although it appears to overpredict the pits and grooves erosion rates due, mainly, to uncertainties in incident energies and angles for sputtering ions and since it does not account for local redeposition of sputtered material. Since the model accurately simulates the erosion pattern but tends to overpredict the erosion rates for both the two- and three-grid sets, this comparative analysis clearly shows how the decel grid significantly suppresses the erosion of the downstream surface of the accel grid as observed in experimental tests. The results also show that the decel grid has a relatively small effect on barrel erosion (erosion of the aperture wall) and erosion of the upstream surface of the accel grid. Decreasing the accel grid voltage of the XIPS can reduce barrel (and total) erosion of the accel grid and should be considered for high-Delta V missions.
C1 [Wirz, Richard E.; Anderson, John R.; Goebel, Dan M.; Katz, Ira] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Wirz, RE (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM Richard.E.Wirz@nasa.jpl.gov
NR 12
TC 3
Z9 3
U1 1
U2 3
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA
SN 0093-3813
J9 IEEE T PLASMA SCI
JI IEEE Trans. Plasma Sci.
PD OCT
PY 2008
VL 36
IS 5
BP 2122
EP 2129
DI 10.1109/TPS.2008.2001041
PN 1
PG 8
WC Physics, Fluids & Plasmas
SC Physics
GA 378ZG
UT WOS:000261363100017
ER
PT J
AU Polk, JE
Sekerak, MJ
Ziemer, JK
Schein, J
Qi, NS
Anders, A
AF Polk, James E.
Sekerak, Michael J.
Ziemer, John K.
Schein, Jochen
Qi, Niansheng
Anders, Andre
TI A Theoretical Analysis of Vacuum Arc Thruster and Vacuum Arc Ion
Thruster Performance
SO IEEE TRANSACTIONS ON PLASMA SCIENCE
LA English
DT Article
DE Cathodes; plasma arc devices; space vehicle propulsion; vacuum arcs
ID CHARGE-STATE DISTRIBUTIONS; CATHODE EROSION; MAGNETIC-FIELDS;
PARAMETERS; PLASMAS; IONIZATION; DEPENDENCE; CURRENTS; VOLTAGE; REGION
AB Thrusters that exploit vacuum arc discharges to produce high-velocity plasma jets directly or as sources of plasma that is subsequently accelerated electrostatically have been proposed or are currently under development. Vacuum arc discharges exhibit certain regularities in their behavior that allow the performance of these thrusters to be described by simple semiempirical models. Empirical data on the current density distribution, charge state and velocity of ions created in vacuum are discharges, and the total cathode mass loss rate are used to develop expressions for the expected thrust and specific impulse as a function of thruster geometry. Thruster electrical efficiency and thrust-to-power ratio are calculated based on measurements of the burning voltage for given thruster operating parameters. Estimates of achievable thruster performance for a wide range of cathode materials are presented. This analysis suggests that thrusters using vacuum arc sources can be operated efficiently with a range of propellant options that gives great flexibility in specific impulse. In addition, the efficiency of plasma production in these devices appears to be largely independent of scale because the metal vapor is ionized within tens of micrometers of the cathode electron emission sites, so this approach is well suited for micropropulsion.
C1 [Polk, James E.] CALTECH, Jet Prop Lab, Prop & Mat Engn Sect, Pasadena, CA 91109 USA.
[Sekerak, Michael J.] Sandia Natl Labs, Missile Syst Grp, Albuquerque, NM 87185 USA.
[Ziemer, John K.] CALTECH, Jet Prop Lab, Elect Prop Grp, Pasadena, CA 91109 USA.
[Schein, Jochen] Univ German Armed Forces, Munich, Germany.
[Qi, Niansheng] Pulse Sci, L3 Commun, San Leandro, CA 94577 USA.
[Anders, Andre] Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA.
RP Polk, JE (reprint author), CALTECH, Jet Prop Lab, Prop & Mat Engn Sect, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM james.e.polk@jpl.nasa.gov
RI Anders, Andre/B-8580-2009
OI Anders, Andre/0000-0002-5313-6505
NR 39
TC 19
Z9 20
U1 1
U2 8
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA
SN 0093-3813
EI 1939-9375
J9 IEEE T PLASMA SCI
JI IEEE Trans. Plasma Sci.
PD OCT
PY 2008
VL 36
IS 5
BP 2167
EP 2179
DI 10.1109/TPS.2008.2004374
PN 1
PG 13
WC Physics, Fluids & Plasmas
SC Physics
GA 378ZG
UT WOS:000261363100022
ER
PT J
AU Polzin, KA
AF Polzin, Kurt A.
TI Scaling and Systems Considerations in Pulsed Inductive Plasma Thrusters
SO IEEE TRANSACTIONS ON PLASMA SCIENCE
LA English
DT Article
DE Faraday Accelerator with Radio-frequency-Assisted; Discharge (FARAD);
inductive ionization; inductive plasma acceleration; pulsed inductive
thruster (PIT)
ID ACCELERATION
AB Performance scaling in pulsed inductive thrusters is discussed in the context of previous experimental studies and modeling results. Two processes, propellant ionization and acceleration, are interconnected, where overall thruster performance and operation are concerned, but they are separated here to gain physical insight into each process and arrive at quantitative criteria that should be met to address or mitigate inherent inductive thruster difficulties. The use of preionization to lower the discharge energy relative to the case where no preionization is employed, and to influence the location of the initial current sheet, is described. The relevant performance scaling parameters for the acceleration stage are reviewed, emphasizing their physical importance and the numerical values required for efficient acceleration. The scaling parameters are then related to the design of the acceleration coil and the pulsed power train that provides current to the acceleration stage. An accurate numerical technique that allows computation of the inductance of a planar. acceleration coil using an axisymmetric magnetostatic solver is described and validated against measured coil inductance values. Requirements for the pulsed power train are reviewed. Several power train and circuit topologies are described, highlighting the impact that each can have on inductive thruster performance and on systems issues associated with high-current switching, lifetime, and power consumption.
C1 NASA, Marshall Space Flight Ctr, Prop Res & Dev Lab, Huntsville, AL 35812 USA.
RP Polzin, KA (reprint author), NASA, Marshall Space Flight Ctr, Prop Res & Dev Lab, Huntsville, AL 35812 USA.
EM kurt.a.polzin@nasa.gov
NR 21
TC 7
Z9 7
U1 1
U2 2
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA
SN 0093-3813
J9 IEEE T PLASMA SCI
JI IEEE Trans. Plasma Sci.
PD OCT
PY 2008
VL 36
IS 5
BP 2189
EP 2198
DI 10.1109/TPS.2008.2003537
PN 1
PG 10
WC Physics, Fluids & Plasmas
SC Physics
GA 378ZG
UT WOS:000261363100024
ER
PT J
AU Katz, I
Mikellides, IG
Goebel, DM
Polk, JE
AF Katz, Ira
Mikellides, Ioannis G.
Goebel, Dan M.
Polk, James E.
TI Insert Heating and Ignition in Inert-Gas Hollow Cathodes
SO IEEE TRANSACTIONS ON PLASMA SCIENCE
LA English
DT Article
DE Electric propulsion life modeling; hollow cathode; numerical simulation
of partially ionized gas
AB An extensive 2-D computational model of the fundamental ionization and transport processes that occur inside electric propulsion hollow cathodes has been developed over the last few years. The computed charged-particle fluxes from the plasma to the internal cathode surfaces have been used as. input to a rudimentary hollow-cathode thermal model also developed recently. It is shown that, in hollow cathodes with a very small diameter orifice, the plasma density peaks inside the orifice and that the cathode is heated primarily by the orifice plate which is, in turn, heated by the plasma inside the orifice and along the orifice plate. As the orifice diameter increases the peak plasma density moves upstream of the orifice with ions and electrons contributing to the heating of both the orifice plate and the insert. In hollow cathodes with a very large diameter orifice the plasma extends along much of the insert, the plasma density peaks well within the insert region, and the cathode is heated primarily by ion bombardment of the insert. By solving a 2-D axisymmetric boundary value problem, it is also shown that when a voltage is applied between the ends of a long cylindrical channel the potential in the absence of the plasma falls almost by one order of,magnitude with each radius downstream of the entrance. The implication is that cathodes with orifices of large length-to-radius ratio will be harder to ignite.
C1 [Katz, Ira; Mikellides, Ioannis G.] CALTECH, Jet Prop Lab, Elect Prop Grp, Pasadena, CA 91109 USA.
RP Katz, I (reprint author), CALTECH, Jet Prop Lab, Elect Prop Grp, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM ira.katz@jpl.nasa.gov; ioannis.g.mikellides@jpl.nasa.gov;
dan.m.goebel@jpl.nasa.gov; james.e.polk@jpl.nasa.gov
NR 14
TC 6
Z9 6
U1 2
U2 18
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA
SN 0093-3813
J9 IEEE T PLASMA SCI
JI IEEE Trans. Plasma Sci.
PD OCT
PY 2008
VL 36
IS 5
BP 2199
EP 2206
DI 10.1109/TPS.2008.2004363
PN 1
PG 8
WC Physics, Fluids & Plasmas
SC Physics
GA 378ZG
UT WOS:000261363100025
ER
PT J
AU Cho, M
Garrett, HB
Hilgers, A
Lai, ST
Payan, D
Roussel, JF
AF Cho, Mengu
Garrett, Henry B.
Hilgers, Alain
Lai, Shu T.
Payan, Denis
Roussel, Jean-Francois
TI Special Issue on Spacecraft Charging Technology
SO IEEE TRANSACTIONS ON PLASMA SCIENCE
LA English
DT Editorial Material
C1 [Cho, Mengu] Kyushu Inst Technol, Kitakyushu, Fukuoka 8048550, Japan.
[Garrett, Henry B.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
[Hilgers, Alain] European Space Agcy, NL-2200 AG Noordwijk, Netherlands.
[Lai, Shu T.] AF Res Lab, Hanscom AFB, Bedford, MA 01731 USA.
[Payan, Denis] CNES, F-31401 Toulouse 9, France.
[Roussel, Jean-Francois] Off Natl Etud & Rech Aerosp, F-31055 Toulouse 4, France.
RP Cho, M (reprint author), Kyushu Inst Technol, Kitakyushu, Fukuoka 8048550, Japan.
NR 0
TC 0
Z9 0
U1 0
U2 2
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA
SN 0093-3813
J9 IEEE T PLASMA SCI
JI IEEE Trans. Plasma Sci.
PD OCT
PY 2008
VL 36
IS 5
BP 2218
EP 2218
DI 10.1109/TPS.2008.2006198
PN 2
PG 1
WC Physics, Fluids & Plasmas
SC Physics
GA 378ZH
UT WOS:000261363200001
ER
EF