FN Thomson Reuters Web of Science™ VR 1.0 PT J AU Vayner, B Ferguson, DC Galofaro, JT AF Vayner, Boris Ferguson, Dale C. Galofaro, Joel T. TI Emission Spectra of Arc Plasmas SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article DE Arc current; arc plasma; arc spectrum; cathode material; sustained arc; temperature ID VACUUM-ARC; SOLAR-ARRAYS; ENVIRONMENT AB Emission spectra of arc plasmas contain valuable information regarding arc sites, plasma parameters and composition, and temporal dynamics of plasma expansion. Emission spectra within the range of 200-800 nm were measured for trigger arcs on triple junctions and sustained arcs between solar array strings. Spectra were recorded from arcs on several different brands of conventionally designed solar array samples immersed in simulated low-Earth-orbit plasma. The arc sites and cathode materials were determined for plasmas generated by primary discharges and sustained arcs. Comparative analysis of temporal dynamics of arc current pulse waveforms with spectral line intensities allowed obtaining estimates for plasma expansion rates. Statistical processing of spectral line intensities resulted in calculations of arc plasma electron temperatures and surface densities of some atomic species. The presence of a flux of energetic electrons (above 100 eV) was confirmed by analysis of the structure of the excited atom and ion energy levels. C1 [Vayner, Boris] Ohio Aerosp Inst, Cleveland, OH 44142 USA. [Ferguson, Dale C.] NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. [Galofaro, Joel T.] NASA, John H Glenn Res Ctr, Photovalta & Space Environm Branch, Cleveland, OH 44135 USA. RP Vayner, B (reprint author), Ohio Aerosp Inst, Cleveland, OH 44142 USA. EM boris.v.vayner@nasa.gov; Dale.C.Ferguson-l@nasa.gov; joel.t.galofaor@nasa.gov FU NEDO (Japan) FX The authors would like to thank NEDO (Japan) grant for providing some of the test samples. NR 20 TC 5 Z9 5 U1 4 U2 12 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 2219 EP 2227 DI 10.1109/TPS.2008.2001424 PN 2 PG 9 WC Physics, Fluids & Plasmas SC Physics GA 378ZH UT WOS:000261363200002 ER PT J AU Wright, KH Swenson, CM Thompson, DC Barjatya, A Koontz, SL Schneider, TA Vaughn, JA Minow, JI Craven, PD Coffey, VN Parker, LN But, TH AF Wright, Kenneth H., Jr. Swenson, Charles M. Thompson, Donald C. Barjatya, Aroh Koontz, Steven L. Schneider, Todd A. Vaughn, Jason A. Minow, Joseph I. Craven, Paul D. Coffey, Victoria N. Parker, Linda N. But, Them H. TI Charging of the International Space Station as Observed by the Floating Potential Measurement Unit: Initial Results SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article DE Ionosphere; plasma measurements; spacecraft charging; space stations ID SHORT DIPOLE ANTENNA; LANGMUIR PROBE; MAGNETOPLASMA; IONOSPHERE; IMPEDANCE; PLASMA; MODEL AB The Floating Potential Measurement Unit (FPMU) is a multiprobe package designed to measure the floating potential of the International Space Station (ISS) as well as the density and temperature of the local ionospheric plasma environment. The purpose of the FPMU is to provide direct measurements of ISS spacecraft charging as continuing construction leads to dramatic changes in ISS size and configuration. FPMU data are used for refinement and validation of the ISS spacecraft charging models used to evaluate the severity and frequency of occurrence of ISS charging hazards. The FPMU data and the models are also used to evaluate the effectiveness of proposed hazard controls. The FPMU consists of four probes: a floating potential probe, two Langmuir probes, and a plasma impedance probe. These probes measure the floating potential of the ISS, plasma density, and electron temperature. Redundant measurements using different probes support data validation by interprobe comparisons. The FPMU was installed by ISS crew members during an extra-vehicular activity on the starboard (S l) truss of the ISS in early August 2006 when the ISS configuration included only one 160-V U.S. photovoltaic (PV) array module. The first data campaign began a few hours after installation and continued for over five days. Additional data campaigns were completed in 2007 after a second 160-V U.S. PV array module was added to the ISS. This paper discusses the general operational characteristics of the FPMU as integrated on ISS, the functional performance of each probe, the charging behavior of the ISS before and after the addition of a second 160-V U.S. PV array module, and initial results from model comparisons. C1 [Wright, Kenneth H., Jr.] Univ Alabama, Ctr Space Plasma & Aeron Res, Huntsville, AL 35899 USA. [Swenson, Charles M.; Thompson, Donald C.] Utah State Univ, Logan, UT 84322 USA. [Barjatya, Aroh] Embry Riddle Aeronaut Univ, Dept Phys Sci, Daytona Beach, FL 32114 USA. [Koontz, Steven L.] NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. [Schneider, Todd A.; Vaughn, Jason A.; Minow, Joseph I.; Craven, Paul D.; Coffey, Victoria N.] NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. [Parker, Linda N.] Jacobs Technol, Huntsville, AL 35806 USA. [But, Them H.] Motlow State Community Coll, Informat Technol & Telecommun Serv, Lynchburg, TN 37352 USA. RP Wright, KH (reprint author), Univ Alabama, Ctr Space Plasma & Aeron Res, Huntsville, AL 35899 USA. EM Ken.Wright@uah.edu; Charles.Swenson@usu.edu; don.thompson@usu.edu; aroh.barjatya@erau.edu; steven.l.koontz@nasa.gov; todd.schneider@nasa.gov; Jason.A.Vaughn@nasa.gov; Joseph.Minow@nasa.gov; paul.craven@nasa.gov; Victoria.Coffey@nasa.gov; linda.parker@nasa.gov; tbui@mscc.edu FU ISS Program Office; NASA [NNM05AA22A, NNM05AB50C] FX Manuscript received January 31. 2008; revised June 9, 2008. First published October 31, 2008: Current version published November 14, 2008. This work was supported in part by the ISS Program Office and by NASA under Contracts NNM05AA22A and NNM05AB50C. NR 33 TC 6 Z9 7 U1 0 U2 3 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 2280 EP 2293 DI 10.1109/TPS.2008.2003257 PN 2 PG 14 WC Physics, Fluids & Plasmas SC Physics GA 378ZH UT WOS:000261363200009 ER PT J AU Coffey, VN Wright, KH Minow, JI Schneider, TA Vaughn, JA Craven, PD Chandler, MO Koontz, SL Parker, LN Bui, TH AF Coffey, Victoria N. Wright, Kenneth H., Jr. Minow, Joseph I. Schneider, Todd A. Vaughn, Jason A. Craven, Paul D. Chandler, Michael O. Koontz, Steven L. Parker, Linda N. Bui, Them H. TI Validation of the Plasma Densities and Temperatures From the ISS Floating Potential Measurement Unit SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article DE Density measurement; ionosphere; plasma measurement; temperature measurement AB The validation of the floating potential measurement unit (FPMU) plasma density and temperature measurements is an important step in the process of evaluating International Space Station (ISS) spacecraft charging issues including vehicle arcing and hazards to crew during extravehicular activities. The highest potentials observed on the Space Station are due to the combined V(SP) x B effects on a large spacecraft and the collection of ionospheric electron and ion currents by the 160-V U.S. solar array modules. The ionospheric plasma environment is needed for input to the ISS spacecraft charging models used to predict the severity and frequency of occurrence of ISS charging hazards. The validation of these charging models requires the comparison of their predictions with measured FPMU values. The FPMU measurements themselves must also be validated for use in manned flight safety work. This paper presents preliminary results from a comparison of densities and temperatures derived from the FPMU Langmuir probes and plasma impedance probe with the independent density and temperature measurements from a spaceborne ultraviolet imager, a ground-based incoherent scatter radar, and ionosonde sites. C1 [Coffey, Victoria N.; Minow, Joseph I.; Schneider, Todd A.; Vaughn, Jason A.; Craven, Paul D.; Chandler, Michael O.] NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. [Wright, Kenneth H., Jr.] Univ Alabama, Ctr Space Plasma & Aeron Res, Huntsville, AL 35899 USA. [Koontz, Steven L.] NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. [Parker, Linda N.] Jacobs Engn Grp Inc, Jacobs Technol, ESTS Grp, Huntsville, AL 35806 USA. [Bui, Them H.] Motlow State Community Coll, Lynchburg, TN 37352 USA. RP Coffey, VN (reprint author), NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. EM victoria.coffey@nasa.gov; kenneth.h.wright@nasa.gov; Joseph.Minow@nasa.gov; Todd.A.Schneider@nasa.gov; Paul.D.Craven@nasa.gov; Steven.L.Koontz@nasa.gov FU International Space Station Program Office. NASA Johnson Space Center FX Manuscript received January 31. 2008: revised July 1, 2008 and July 23, 2008. First published October 31, 2008; current version published November 14. 2008. This work was supported by the International Space Station Program Office. NASA Johnson Space Center. NR 14 TC 1 Z9 1 U1 0 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 2301 EP 2308 DI 10.1109/TPS.2008.2004271 PN 2 PG 8 WC Physics, Fluids & Plasmas SC Physics GA 378ZH UT WOS:000261363200011 ER PT J AU Mandell, MJ Davis, VA Pencil, EJ Patterson, MJ McEwen, HK Foster, JE Snyder, JS AF Mandell, Myron J. Davis, Victoria A. Pencil, Eric J. Patterson, Michael J. McEwen, Heather K. Foster, John E. Snyder, John Steve TI Modeling the NEXT Multithruster Array Test With Nascap-2k SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article DE Ion engines; plasma measurements; space vehicle propulsion AB Tests of up to three simultaneously firing 40-cm NASA's Evolutionary Xenon Thrusters took place at NASA Glenn Research Center. In addition to numerous engineering tests, the experiment was instrumented to measure plasma properties in the interacting plumes, charge exchange return current to the active and dormant thrusters, and current and plasma properties at various locations. This paper describes the use of Nascap-2k to calculate plume potentials and charge exchange ion return currents to active and dormant ion optics and to diagnostic probes. Calculations were performed varying the numbers of active thrusters, thruster power levels, and gimbaling. The results were extrapolated to space conditions. Despite several simplifying assumptions, we obtained good agreement with experimental results. No major problems associated with multiple thruster operation were found. C1 [Mandell, Myron J.; Davis, Victoria A.] Sci Applicat Int Corp, San Diego, CA 92121 USA. [Pencil, Eric J.; Patterson, Michael J.; McEwen, Heather K.] NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. [Foster, John E.] Univ Michigan, Dept Nucl Engn & Radiol Sci, Ann Arbor, MI 48109 USA. [Snyder, John Steve] CALTECH, Jet Prop Lab, Elect Propuls Grp, Pasadena, CA 91109 USA. RP Mandell, MJ (reprint author), Sci Applicat Int Corp, San Diego, CA 92121 USA. EM myron.j.mandell@saic.com FU National Aeronautics and Space Administration FX Manuscript received July 15, 2007; revised February 5, 2008. Current version published November 14, 2008. This research was supported by the National Aeronautics and Space Administration. Publication was supported by the Air Force Research Laboratory. NR 13 TC 3 Z9 3 U1 0 U2 0 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 2309 EP 2318 DI 10.1109/TPS.2008.2003534 PN 2 PG 10 WC Physics, Fluids & Plasmas SC Physics GA 378ZH UT WOS:000261363200012 ER PT J AU Galofaro, JT Vayner, BV Hillard, GB Ferguson, DC AF Galofaro, Joel T. Vayner, Boris V. Hillard, G. Barry Ferguson, Dale C. TI SSTE-4 Program Advanced Photovoltaic Cell Technologies: Ground Chamber Test Results SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article DE Photovoltaic cells; photovoltaic space power systems; plasma measurements ID VOLTAGE SOLAR-ARRAYS; PLASMA ENVIRONMENT; ELECTRICAL BREAKDOWN; LARGE SPACECRAFT AB Plasma ground-testing results, obtained at the John H. Glenn Research Center National Plasma Interaction Facility, are presented for a number of thin-film photovoltaic cells. The cells represent a mix of promising new technologies identified by the Air Force Research Laboratory under the Space Science Technology Experiment (SSTE-4) Program. The current ground-testing efforts are aimed at characterizing both the performance and survivability of thin-film technologies in the harsh Low Earth Orbit space environment where they are intended to be flown. Measurements of parasitic currents and arc threshold voltages were performed in situ under strictly controlled charging conditions for both amorphous silicon (a-Si) and copper indium gallium selenide cells. Surface flashing on the large-area a-Si cells revealed that microdischarges in the dielectric surface do not appear to cause any apparent degradation to the cells. Catastrophic arc testing between adjacent cells resulted in no sustained arcs. Similar catastrophic arc tests between adjacent strings resulted in self-extinguished nonsustained arc extensions on time scales of approximately 100 mu s in length. All cell efficiency measurements were performed in the Solar Cell Calibration Laboratory prior to plasma testing and then once again after the completion of the plasma tests. C1 [Galofaro, Joel T.; Hillard, G. Barry] NASA, John H Glenn Res Ctr, Cleveland, OH 44135 USA. [Vayner, Boris V.] Ohio Aerosp Inst, Brookpark, OH 44142 USA. [Ferguson, Dale C.] NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Galofaro, JT (reprint author), NASA, John H Glenn Res Ctr, Cleveland, OH 44135 USA. EM Joel.T.Galofaro@nasa.gov; boris.v.vayner@nasa.gov; dale.c.ferguson@nasa.gov FU National Aeronautics and Space Administration (NASA) FX Manuscript received February 20, 2008; revised May 19, 2008. First published October 31, 2008; current version published November 14, 2008. This work was supported in part by the National Aeronautics and Space Administration (NASA). NR 19 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 2425 EP 2433 DI 10.1109/TPS.2008.2002956 PN 2 PG 9 WC Physics, Fluids & Plasmas SC Physics GA 378ZH UT WOS:000261363200024 ER PT J AU Sanmartin, JR Charro, M Lorenzini, EC Garrett, HB Bombardelli, C Bramanti, C AF Sanmartin, Juan R. Charro, Mario Lorenzini, Enrico C. Garrett, Henry B. Bombardelli, Claudio Bramanti, Cristina TI Electrodynamic Tether at Jupiter-I: Capture Operation and Constraints SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article DE Bare electrodynanic (ED) tether; Jovian mission design; planetary exploration; propellantless space propulsion ID LOW-EARTH-ORBIT; CURRENT COLLECTION; EXPLORATION; CURRENTS; PROBE AB Tethered spacecraft missions to the Jovian system suit the use of electrodynamic tethers because: 1) magnetic stresses are 100 times greater than at the Earth; 2) the stationary orbit is one-third the relative distance for Earth; and 3) moon to is a nearby giant plasma source. The (bare) tether is a reinforced aluminum foil with tens of kilometer length L and a fraction of millimeter thickness h, which collects electrons as an efficient Langmuir probe and can tap Jupiter's rotational energy for both propulsion and power. In this paper, the critical capture operation is explicitly formulated in terms of orbit geometry and established magnetic and thermal plasma models. The design parameters L and h and capture perijove radius r(p) face opposite criteria independent of tape width. Efficient capture requires a low r(p) and a high L(3/2)/h ratio. However, combined bounds on tether bowing and tether tensile stress, arising from a spin made necessary by the low Jovian gravity gradient, require a high r(p) and a low L(5/2)/h ratio. Bounds on tether temperature again require a high r(p) and a low L(3/8)/(tether emissivity)(1/4) ratio. Optimal design values are discussed. C1 [Sanmartin, Juan R.; Charro, Mario] Univ Politecn Madrid, Sch Aeronaut Engn, Dept Appl Phys, E-28040 Madrid, Spain. [Lorenzini, Enrico C.] Univ Padua, Dept Mech Engn, I-35100 Padua, Italy. [Garrett, Henry B.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Bombardelli, Claudio; Bramanti, Cristina] European Space Agcy, European Space Res & Technol Ctr, Adv Concepts Team, NL-2200 AG Noordwijk, Netherlands. RP Sanmartin, JR (reprint author), Univ Politecn Madrid, Sch Aeronaut Engn, Dept Appl Phys, E-28040 Madrid, Spain. EM juanr.samnartin@upm.es; mario.charro@upm.es; enrico.lorenzini@unipd.it FU European Space Agency [19696/06]; Spanish Ministry of Science and Technology [ESP2004-01511] FX The work of J. R. Sanmartin and M. Charro was supported in part by the European Space Agency under Contract 19696/06 and in part by the Spanish Ministry of Science and Technology under Grant ESP2004-01511. NR 31 TC 23 Z9 23 U1 0 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 2450 EP 2458 DI 10.1109/TPS.2008.2002580 PN 2 PG 9 WC Physics, Fluids & Plasmas SC Physics GA 378ZH UT WOS:000261363200027 ER PT J AU Jun, I Garrett, HB Kim, W Minow, JI AF Jun, Insoo Garrett, Henry B. Kim, Wousik Minow, Joseph I. TI Review of an Internal Charging Code, NUMIT SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article DE Internal charging; NUMerical InTegration (NUMIT) ID DEPOSITION; DIELECTRICS; ELECTRONS; SPACE AB An internal charging code, which is called NUMerical InTegration, has been used on many occasions to study the charging and discharging characteristics of dielectrics in space. The capabilities and limitations of the code are reviewed in this paper. In particular, the basic assumptions of the model are briefly discussed, and an example for the internal charging in the Juno environment is presented. C1 [Jun, Insoo; Garrett, Henry B.; Kim, Wousik] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Minow, Joseph I.] NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Jun, I (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM jun@jpl.nasa.gov; henry.b.garrett@jpl.nasa.gov; wousik.kim@jpl.nasa.gov; joseph.minow@nasa.gov FU National Aeronautics and Space Administration FX This work was supported by the National Aeronautics and Space Administration. NR 14 TC 19 Z9 24 U1 0 U2 1 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 2467 EP 2472 DI 10.1109/TPS.2008.2003440 PN 2 PG 6 WC Physics, Fluids & Plasmas SC Physics GA 378ZH UT WOS:000261363200029 ER PT J AU Green, NW Dennison, JR AF Green, Nelson Wesley Dennison, J. R. TI Deep Dielectric Charging of Spacecraft Polymers by Energetic Protons SO IEEE TRANSACTIONS ON PLASMA SCIENCE LA English DT Article DE Charge storage; conductivity; dielectric discharge; electrons; protons; radiation-induced conductivity (RIC); resistivity; spacecraft charging ID SECONDARY-ELECTRON EMISSION; FLUENCE MODEL; INSULATORS; CONDUCTIVITY; RESISTIVITY; STORAGE AB The majority of research in the field of spacecraft charging concentrates on electron charging effects with little discussion of charging by protons. For spacecraft orbiting in the traditional LEO and GEO environments, this emphasis on electrons is appropriate since energetic electrons are the dominant species. However, for spacecraft in orbits within the inner radiation belts, or for interplanetary and lunar space probes, proton charging effects may also be of concern. To examine bulk spacecraft charging effects in these environments, several typical highly insulating spacecraft polymers were exposed to energetic protons with energies from 1 to 10 MeV to simulate protons from the solar wind and from solar energetic proton events. Results indicate that effects in proton-charged dielectrics are distinctly different than those observed due to electron charging. In most cases, the positive surface potential continued to increase for periods on the order of minutes to a day, followed by long-time-scale decay at rates similar to those observed for electron charging. All samples charged to positive potentials, with substantially lower magnitudes than for equivalent electron fluence. Possible explanations for the different behavior of the measured surface potentials from proton irradiation are discussed; these are related to the evolving internal charge distribution from energy-dependent electron and proton transport, electron emission, charge migration due to dark current and radiation-induced conductivity, and electron capture by embedded protons. C1 [Green, Nelson Wesley] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Dennison, J. R.] Utah State Univ, Dept Phys, Logan, UT 84321 USA. RP Green, NW (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Nelson.W.Green@jpl.nasa.gov; JR.Dennison@usu.edu RI Dennison, John/C-1225-2014; OI Dennison, JR/0000-0002-5504-3353 FU Jet Propulsion Laboratory, California Institute of Technology; University of California; United States Air Force Academy; Utah State University; National Aeronautics and Space Administration FX The authors would like to thank A. Shapiro, P. Willis, H. Garrett, D. Brinza, C. Benson, H. Kirkham, M. Petkov, and P. Bowerman at the Jet Propulsion Laboratory, California Institute of Technology, Pasadena; C. Casteneda and T. Ward at the University of California, Davis; M. G. McHarg and D. Dunlap at the United States Air Force Academy; and D. Arnfield at Utah State University, Logan, for their contributions of data and expertise. The measurements described in this paper were carried out at the Jet Propulsion Laboratory under a contract with the National Aeronautics and Space Administration. NR 28 TC 7 Z9 8 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 J9 IEEE T PLASMA SCI JI IEEE Trans. Plasma Sci. PD OCT PY 2008 VL 36 IS 5 BP 2482 EP 2490 DI 10.1109/TPS.2008.2003442 PN 2 PG 9 WC Physics, Fluids & Plasmas SC Physics GA 378ZH UT WOS:000261363200031 ER PT J AU Ellis, DL Hastings, BK AF Ellis, David L. Hastings, Brian K. TI Hydrogen embrittlement resistance of GRCop-84 SO INTERNATIONAL JOURNAL OF HYDROGEN ENERGY LA English DT Article DE Hydrogen embrittlement; Mechanical properties; Copper alloy ID IN-SITU COMPOSITES; FRACTURE-TOUGHNESS; NIOBIUM; NB; BEHAVIOR; ALLOYS; GROWTH AB GRCop-84 contains approximately 5.5 wt% Nb. Nb can react with hydrogen and embrittle easily. Previous work had indicated the thermodynamic possibility that Cr2Nb could react with hydrogen and form niobium hydrides in the presence of high pressure hydrogen. In this study, samples were charged with hydrogen and tested in both high pressure gaseous H-2 and He environments to determine if measurable differences existed which indicate that hydrogen embrittlement occurs in GRCop-84. Tensile, notched tensile, stress rupture and low cycle fatigue properties were surveyed. High pressure H-2 environment stress rupture testing resulted in a lower reduction in area than a high pressure He environment, and the LCF lives at high strain ranges fall below the lower 95% confidence interval for the baseline data, but in general no significant differences were noted either between H-2 and He environment tests or between H charged materials and the baseline, uncharged extruded GRCop-84 data sets. There was also no discernable evidence of the formation of hydrides or changes in fracture morphology indicating hydrogen embrittlement occurred. Published by Elsevier Ltd on behalf of International Association for Hydrogen Energy. C1 [Ellis, David L.] NASA, Glenn Res Ctr, Struct & Mat Div, Cleveland, OH 44135 USA. [Hastings, Brian K.] NASA, George C Marshall Space Flight Ctr, ERC Jacobs Sverdrup Technol, Huntsville, AL 35812 USA. RP Ellis, DL (reprint author), NASA, Glenn Res Ctr, Struct & Mat Div, MS 49-1,21000 Brookpk Rd, Cleveland, OH 44135 USA. EM david.1.ellis@nasa.gov NR 37 TC 2 Z9 2 U1 2 U2 5 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0360-3199 EI 1879-3487 J9 INT J HYDROGEN ENERG JI Int. J. Hydrog. Energy PD OCT PY 2008 VL 33 IS 20 BP 5661 EP 5671 DI 10.1016/j.ijhydene.2008.05.057 PG 11 WC Chemistry, Physical; Electrochemistry; Energy & Fuels SC Chemistry; Electrochemistry; Energy & Fuels GA 373YI UT WOS:000261009000046 ER PT J AU Tesch, PA Gustafsson, T von Walden, F Linnehlan, RM Trappe, TA AF Tesch, Per A. Gustafsson, Thomas von Walden, Ferdinand Linnehlan, Richard M. Trappe, Todd A. TI Reliability of results and interpretation of measures of 3-methylhistidine in muscle interstitium as marker of muscle proteolysis - Reply to Rennie, Phillips, and Smith SO JOURNAL OF APPLIED PHYSIOLOGY LA English DT Letter ID PROTEIN-SYNTHESIS; HUMANS C1 [Tesch, Per A.] Mid Sweden Univ, Dept Hlth Sci, SE-83125 Ostersund, Sweden. [Tesch, Per A.; von Walden, Ferdinand] Karolinska Inst, Dept Physiol & Pharmacol, Stockholm, Sweden. [Gustafsson, Thomas] Karolinska Inst, Dept Lab Med, Stockholm, Sweden. [Trappe, Todd A.] Ball State Univ, Human Performance Lab, Muncie, IN 47306 USA. [Linnehlan, Richard M.] NASA, Lyndon B Johnson Space Ctr, Astronaut Off, Houston, TX 77058 USA. RP Tesch, PA (reprint author), Mid Sweden Univ, Dept Hlth Sci, SE-83125 Ostersund, Sweden. EM Per.Tesch@miun.se NR 6 TC 2 Z9 2 U1 1 U2 6 PU AMER PHYSIOLOGICAL SOC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 USA SN 8750-7587 J9 J APPL PHYSIOL JI J. Appl. Physiol. PD OCT PY 2008 VL 105 IS 4 BP 1382 EP 1383 DI 10.1152/japplphysiol.90870.2008 PG 2 WC Physiology; Sport Sciences SC Physiology; Sport Sciences GA 357PA UT WOS:000259857400061 ER PT J AU Livingston, JM Schmid, B Russell, PB Redemann, J Podolske, JR Diskin, GS AF Livingston, J. M. Schmid, B. Russell, P. B. Redemann, J. Podolske, J. R. Diskin, G. S. TI Comparison of Water Vapor Measurements by Airborne Sun Photometer and Diode Laser Hygrometer on the NASA DC-8 SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID SOLAR TRANSMITTANCE MEASUREMENTS; LOWER TROPOSPHERIC AEROSOL; GROUND-BASED MEASUREMENTS; OPTICAL-DEPTH SPECTRA; COLUMN CLOSURE; SOLVE-II; ACE-ASIA; IN-SITU; AIRCRAFT; OZONE AB In January-February 2003, the 14-channel NASA Ames airborne tracking sun photometer (AATS) and the NASA Langley/Ames diode laser hygrometer (DLH) were flown on the NASA DC-8 aircraft. The AATS measured column water vapor on the aircraft-to-sun path, while the DLH measured local water vapor in the free stream between the aircraft fuselage and an outboard engine cowling. The AATS and DLH measurements have been compared for two DC-8 vertical profiles by differentiating the AATS column measurement and/or integrating the DLH local measurement over the altitude range of each profile (7.7-10 km and 1.1-12.5 km). These comparisons extend, for the first time, tests of AATS water vapor retrievals to altitudes > similar to 6 km and column contents < 0.1 g cm(-2). To the authors' knowledge, this is the first time suborbital spectroscopic water vapor measurements using the 940-nm band have been tested in conditions so high and dry. Values of layer water vapor (LWV) calculated from the AATS and DLH measurements are highly correlated for each profile. The composite dataset yields r(2) 0.998, rms difference 7.7%, and bias (AATS minus DLH) 1.0%. For water vapor densities AATS and DLH had r(2) 0.968, rms difference 27.6%, and bias (AATS minus DLH) -4.2%. These results for water vapor density compare favorably with previous comparisons of AATS water vapor to in situ results for altitudes < similar to 6 km, columns similar to 0.1 to 5 g cm(-2), and densities similar to 0.1 to 17 g m(-3). C1 [Livingston, J. M.] SRI Int, Menlo Pk, CA 94025 USA. [Schmid, B.] Pacific NW Natl Lab, Richland, WA 99352 USA. [Russell, P. B.; Podolske, J. R.] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. [Redemann, J.] Bay Area Environm Res Inst, Sonoma, CA USA. [Diskin, G. S.] NASA, Langley Res Ctr, Hampton, VA 23665 USA. RP Livingston, JM (reprint author), SRI Int, 333 Ravenswood Ave, Menlo Pk, CA 94025 USA. EM john.livingston@sri.com FU NASA's Upper Atmosphere Research Program; NASA's Solar Occultation Satellite Science Team FX We thank James Eilers and Richard Kolyer for supporting AATS measurements and Stephanie Ramirez for help with illustrations and formatting. The SOLVE II measurements were supported by NASA's Upper Atmosphere Research Program. AATS analyses were supported by NASA's Solar Occultation Satellite Science Team. NR 34 TC 2 Z9 2 U1 0 U2 4 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 OCT PY 2008 VL 25 IS 10 BP 1733 EP 1743 DI 10.1175/2008JTECHA1047.1 PG 11 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 363ZY UT WOS:000260307200001 ER PT J AU Chang, R Nam, J Holtorf, H Emami, K Jeevarajan, A Wu, HL Sun, W AF Chang, Robert Nam, Jae Holtorf, Heidi Emami, Kamal Jeevarajan, Antony Wu, Honglu Sun, Wei TI Direct cell writing of 3D tissue micro-organs for drug metabolism study SO JOURNAL OF BIOTECHNOLOGY LA English DT Meeting Abstract C1 [Chang, Robert; Nam, Jae; Sun, Wei] Drexel Univ, Dept Mech Engn & Mech, Philadelphia, PA 19103 USA. [Holtorf, Heidi; Emami, Kamal; Jeevarajan, Antony; Wu, Honglu] NASA, Lyndon B Johnson Space Ctr, Radiat Phys Lab, Houston, TX 77058 USA. EM sunwei@drexel.edu NR 3 TC 1 Z9 1 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-1656 EI 1873-4863 J9 J BIOTECHNOL JI J. Biotechnol. PD OCT PY 2008 VL 136 SU S MA II5-Y-006 BP S144 EP S145 DI 10.1016/j.jbiotec.2008.07.308 PG 2 WC Biotechnology & Applied Microbiology SC Biotechnology & Applied Microbiology GA V32VT UT WOS:000208979400329 ER PT J AU Lee, MI Suarez, MJ Kang, IS Held, IM Kim, D AF Lee, Myong-In Suarez, Max J. Kang, In-Sik Held, Isaac M. Kim, Daehyun TI A moist benchmark calculation for atmospheric general circulation models SO JOURNAL OF CLIMATE LA English DT Article ID TROPICAL INTRASEASONAL OSCILLATION; INTERTROPICAL CONVERGENCE ZONES; MADDEN-JULIAN OSCILLATION; COUPLED EQUATORIAL WAVES; LARGE-SCALE MODELS; BOUNDARY-LAYER; GLOBAL PRECIPITATION; AGCM SIMULATIONS; ARAKAWA-SCHUBERT; SUMMER MONSOON AB A benchmark calculation is designed to compare the climate and climate sensitivity of atmospheric general circulation models (AGCMs). The experimental Setup basically follows that of the aquaplanet experiment (APE) proposed by Neale and Hoskins, but a simple mixed layer ocean is embedded to enable air-sea coupling and the Prediction of surface temperature. In calculations with several AGCMs, this idealization produces very strong zonal-mean flow and exaggerated ITCZ strength. but the model simulations remain sufficiently realistic to justify the use of this frame work in isolating key differences between models. Because Surface temperatures are free to respond to model differences, the simulation of the cloud distribution. especially in the subtropics. affects many other aspects of the simulations. The analysis of the simulated tropical transients highlights the importance of convection inhibition and air-sea coupling as affected by the depth of the mixed layer. These preliminary comparisons demonstrate that this idealized benchmark provides a discriminating framework for understanding the implications of differing physics parameterization in AGCMs. C1 [Lee, Myong-In] NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Greenbelt, MD 20771 USA. [Lee, Myong-In] Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21228 USA. [Kang, In-Sik] Seoul Natl Univ, Sch Earth & Environm Sci, Seoul, South Korea. [Held, Isaac M.] NOAA, Geophys Fluid Dynam Lab, Princeton, NJ USA. [Kim, Daehyun] Seoul Natl Univ, Sch Earth & Environm Sci, Seoul, South Korea. RP Lee, MI (reprint author), NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Code 610-1, Greenbelt, MD 20771 USA. EM myong-in.lee@nasa.gov RI 안, 민섭/D-9972-2015; OI Lee, Myong-In/0000-0001-8983-8624 FU NASA Earth Science Enterprise's Modeling, Analysis, and Prediction (MAP); Korea Meteorological Administration Research and Development [CATER_2006-4206]; BK21 FX We thank David Straus and three anonymous reviewers whose comments were very constructive in improving the original manuscript. We also thank Julio Bacmeister and In-Sun Song for their helpful discussions and suggestions to this study. This study was supported by NASA Earth Science Enterprise's Modeling, Analysis, and Prediction (MAP) program. In-Sik Kang and Daehyun Kim have been supported by the Korea Meteorological Administration Research and Development Program under Grant CATER_2006-4206 and the BK21 program. NR 57 TC 15 Z9 15 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 OCT PY 2008 VL 21 IS 19 BP 4934 EP 4954 DI 10.1175/2008JCLI1891.1 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 353WO UT WOS:000259599900003 ER PT J AU Bednarcyk, BA Aboudi, J Arnold, SM Sullivan, RM AF Bednarcyk, Brett A. Aboudi, Jacob Arnold, Steven M. Sullivan, Roy M. TI Analysis of Space Shuttle external tank spray-on foam insulation with internal pore pressure SO JOURNAL OF ENGINEERING MATERIALS AND TECHNOLOGY-TRANSACTIONS OF THE ASME LA English DT Article ID CELL CELLULAR SOLIDS; MICROMECHANICAL ANALYSIS; POLYMER FOAMS; FIELD; COMPOSITES; STIFFNESS; MATRIX; MODEL AB The polymer spray-on foam insulation used on NASA's Space Shuttle external fuel tank is analyzed via the high-fidelity generalized method of cells micromechanical model. This model has been enhanced to include internal pore pressure, which is applied as a boundary condition on the internal faces of the foam pores. The pore pressure arises due to both ideal gas expansion during a temperature change as well as outgassing of species from the foam polymer material. Material creep and elastic stiffening are also incorporated via appropriate constitutive models. Due to the lack of reliable properties for the in situ foam polymer material, these parameters are backed out from foam thermomechanical test data. Parametric studies of the effects of key variables (both property-related and microstructural) are presented as is a comparison of model predictions for the thermal expansion behavior of the foam with experimental data. C1 [Bednarcyk, Brett A.; Arnold, Steven M.; Sullivan, Roy M.] NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. [Aboudi, Jacob] Tel Aviv Univ, IL-69978 Tel Aviv, Israel. RP Bednarcyk, BA (reprint author), NASA, Glenn Res Ctr, 21000 Brookpk Rd, Cleveland, OH 44135 USA. EM brett.a.bednarcyk@nasa.gov NR 44 TC 1 Z9 1 U1 0 U2 3 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 0094-4289 J9 J ENG MATER-T ASME JI J. Eng. Mater. Technol.-Trans. ASME PD OCT PY 2008 VL 130 IS 4 AR 041005 DI 10.1115/1.2969247 PG 16 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA 350TJ UT WOS:000259375700005 ER PT J AU Ivins, ER Wolf, D AF Ivins, Erik R. Wolf, Detlef TI Glacial isostatic adjustment: New developments from advanced observing systems and modeling SO JOURNAL OF GEODYNAMICS LA English DT Review DE Ice sheets; Glacial geochronology; Mantle viscosity; GRACE; GOCE; Altimetry; GPS; Tidal gravimetery; Hydrology models; Time-varying gravity ID MANTLE VISCOSITY; ICE-SHEET; GRAVITY; GRACE; FLOW; CRUSTAL; MOTION; ALASKA; OCEAN; EARTH AB The measurement of glacial isostatic adjustment (GIA) is one of the key ways in which geophysicists probe the long-term mantle rheology and Pleistocene ice history. GIA models are also tied to global and regional relative sea-level (RSL) histories, to 20th century tide-gauge (TG) data and to space and terrestrial geodetic measurements. Two new types of observation are related to the high-resolution space-gravity data recovered from the Gravity and Climate Experiment (GRACE) satellite pair and the soon-to-be launched Gravity and Ocean Circulation Experiment (GOCE) with on-board three-component gradiometer. Gravity mapping has the unique capability of isolating those regions that lack isostatic equilibrium. When coupled with other space and terrestrial geodetic measurements, such as those of the Global Positioning System (GPS) networks and with multi-decade terrestrial gravity data, new constraints on CIA are in the offing and should soon illuminate new interpretations of ice-sheet history and mantle response. CIA studies also incorporate space-based altimetry data, which now provide multi-decadal coverage over continents, oceans and lakes. As we are approaching 72 monthly solutions of GRACE gravity coefficients for determining the Earth's secular component of gravity change over the continents, a new issue has surfaced: the problem of relying on interannual hydrological modeling to determine the hydrological contribution to the linear trend in the gravity field. Correctly extracting this contribution is germane to using the CIA-driven component for modeling solid-Earth and paleo-climatic parameters. Seismic and heat-flux-based models of the Earth's interior are emerging with ever higher levels of sophistication regarding material strength (or viscosity). A basic question raised is: how good are traditional Newtonian and non-Newtonian viscosity models that only allow radial variations of Earth parameters? In other words: under what circumstances must this assumption be abandoned for joint interpretations of new and traditional data sets. In this short review we summarize the issues raised in the papers forming this special issue (SI) dedicated to GIA. (C) 2008 Elsevier Ltd. All rights reserved C1 [Ivins, Erik R.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Wolf, Detlef] German Res Ctr Geosci, Potsdam, Germany. [Wolf, Detlef] Univ Stuttgart, Inst Geodesy, Stuttgart, Germany. RP Ivins, ER (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM erik.r.lvins@jpl.nasa.gov RI Ivins, Erik/C-2416-2011 FU NASA; German Research Foundation (DFG) FX The work of E.I. was performed at the jet Propulsion Laboratory, Caltech, and funded by the Solid Earth and Surface Processes Focus Area for GRACE Science within NASA's Earth Science Program. The work of D.W. is related priority program SPP 1257 Mass Transport and Mass Distribution in the Earth System funded by the German Research Foundation (DFG). The Editor-in-Chief of the journal of Geodynamics, Randell Stephenson, is thanked for a review of the manuscript. NR 69 TC 13 Z9 14 U1 1 U2 5 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0264-3707 J9 J GEODYN JI J. Geodyn. PD OCT PY 2008 VL 46 IS 3-5 SI SI BP 69 EP 77 DI 10.1016/j.jog.2008.06.002 PG 9 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 364UL UT WOS:000260360800001 ER PT J AU Klemann, V Martinec, Z Ivins, ER AF Klemann, Volker Martinec, Zdenek Ivins, Erik R. TI Glacial isostasy and plate motion SO JOURNAL OF GEODYNAMICS LA English DT Article DE Glacial-isostatic adjustment; Tectonic-plate motion; Surface motion; Plate boundaries; Lithosphere; ITRF2005 ID LATERAL VISCOSITY VARIATIONS; GRAVITATING MAXWELL EARTH; RELAXATION-TIME SPECTRUM; INDUCED SURFACE MOTION; SEA-LEVEL CHANGE; MANTLE VISCOSITY; LITHOSPHERIC THICKNESS; GLOBAL-MODEL; ADJUSTMENT; FENNOSCANDIA AB The influence of glacial-isostatic adjustment (GIA) on the motion of tectonic plates is usually neglected. Employing a recently developed numerical approach, we examine the effect of glacial loading on the motion of the Earth's tectonic plates where we consider an elastic lithosphere of laterally variable Strength and the plates losely connected by low viscous zones. The aim of this paper is to elucidate the physical processes which control the GIA-induced horizontal motion and to assess the impact of finite plate-boundary zones. We show that the present-day motion of tectonic plates induced by GIA is at, or above, the order of accuracy of the plate motions determined by very precise GPS observations. Therefore, its contribution should be considered when interpreting the mechanism controlling plate motion. (C) 2008 Elsevier Ltd. All rights reserved. C1 [Klemann, Volker] GeoForschungsZentrum Potsdam, Dept Geodesy & Remote Sensing, D-14473 Potsdam, Germany. [Martinec, Zdenek] Charles Univ Prague, Prague, Czech Republic. [Ivins, Erik R.] CALTECH, Jet Prop Lab, Pasadena, CA USA. RP Klemann, V (reprint author), GeoForschungsZentrum Potsdam, Dept Geodesy & Remote Sensing, D-14473 Potsdam, Germany. EM volkerk@gfz-potsdam.de RI Klemann, Volker/H-3660-2013 OI Klemann, Volker/0000-0002-8342-8947 FU German Research Foundation (DFG); Czech Republic [205/06/0580]; NASA FX The work of the first author was supported by the priority program SPP 1257 of the German Research Foundation (DFG). The second author acknowledges the support from the Grant Agency of the Czech Republic through grant no. 205/06/0580. The third author was supported by NASA's Interdisciplinary Earth Science Program and by the Solid Earth and Surface Processes Focus Area, performed at JPL, Caltech, Pasadena under contract with NASA. Suggestions of Roberto Sabadini and a further anonymous reviewer of a previous version of the paper are acknowledged as the suggestions to the current review process. NR 51 TC 18 Z9 22 U1 2 U2 9 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0264-3707 J9 J GEODYN JI J. Geodyn. PD OCT PY 2008 VL 46 IS 3-5 SI SI BP 95 EP 103 DI 10.1016/j.jog.2008.04.005 PG 9 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 364UL UT WOS:000260360800004 ER PT J AU Hatamleh, O AF Hatamleh, Omar TI The effects of laser peening and shot peening on mechanical properties in friction stir welded 7075-T7351 Aluminum SO JOURNAL OF MATERIALS ENGINEERING AND PERFORMANCE LA English DT Article DE friction stir welding; laser peening; mechanical properties; shot peening ID FATIGUE-CRACK GROWTH; RESIDUAL-STRESSES; BEHAVIOR; MICROSTRUCTURE; ALLOYS AB Peening techniques like laser peening and shot peening were used to modify the surface of friction stir welded 7075-T7351 Aluminum Alloy specimens. The tensile coupons were machined such as the loading was applied in a direction perpendicular to the weld direction. The peening effects on the global and local mechanical properties through the different regions of the weld were characterized and assessed. The surface hardness levels resulting from various peening techniques were also investigated for both sides of the welds. Shot peening resulted in an increase to surface hardness levels, but no improvement was noticed on the mechanical properties. In contrast, mechanical properties were improved by laser peening when compared to the unpeened material. C1 NASA, Struct & Dynam Branch, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. RP Hatamleh, O (reprint author), NASA, Struct & Dynam Branch, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. EM omar.hatamleh-1@nasa.gov NR 21 TC 13 Z9 13 U1 4 U2 18 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1059-9495 J9 J MATER ENG PERFORM JI J. Mater. Eng. Perform. PD OCT PY 2008 VL 17 IS 5 BP 688 EP 694 DI 10.1007/s11665-007-9163-7 PG 7 WC Materials Science, Multidisciplinary SC Materials Science GA 347LG UT WOS:000259142500010 ER PT J AU Vettraino, LG Heelan, JL Faconti, CA Walley, JL Garg, A Groza, JR Gibeling, JC AF Vettraino, L. G. Heelan, J. L. Faconti, C. A. Walley, J. L. Garg, A. Groza, J. R. Gibeling, J. C. TI Influence of processing on the microstructure of Cu-8Cr-4Nb SO JOURNAL OF MATERIALS SCIENCE LA English DT Article; Proceedings Paper CT 7th Pacific Rim Conference on Ceramic and Glass Technology CY NOV 11-14, 2007 CL Shanghai, PEOPLES R CHINA ID ALLOY AB The particle-strengthened Cu-8 at.%Cr-4 at.%Nb alloy is processed by consolidation of atomized powders followed by extrusion to obtain bars and rolling to produce sheets. Comparison of copper matrix grain and second-phase particle structures in both extruded and rolled Cu-8Cr-4Nb was performed. Extruded material displayed locally banded arrangements of Cr2Nb particles, while the distribution of particles was more uniform in rolled material. Mean Cr2Nb particle sizes were found to be essentially the same for both processing methods. Non-spherical particles in the extruded alloy showed some preferred orientation, whereas the rolled material displayed a more uniform particle orientation distribution. Extruded material exhibited a dual grain size distribution with smaller grains in banded regions. The mean grain size of 1.36 mu m in extruded material was larger than the 0.65 mu m grain size of rolled material. A [101] texture was evident in extruded material, whereas the rolled material was only slightly textured along the [001] and [111] directions. The processing differences for the rolled and extruded forms give rise to different microstructures and hence higher creep strength for the extruded material in the temperature range of 773-923 K. C1 [Vettraino, L. G.; Heelan, J. L.; Faconti, C. A.; Walley, J. L.; Groza, J. R.; Gibeling, J. C.] Univ Calif Davis, Dept Chem Engn & Mat Sci, Davis, CA 95616 USA. [Garg, A.] NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Gibeling, JC (reprint author), Univ Calif Davis, Dept Chem Engn & Mat Sci, 1 Shields Ave, Davis, CA 95616 USA. EM jcgibeling@ucdavis.edu RI Carter, Jennifer/A-3241-2013 OI Carter, Jennifer/0000-0001-6702-729X NR 15 TC 3 Z9 3 U1 0 U2 3 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 OCT PY 2008 VL 43 IS 19 BP 6546 EP 6555 DI 10.1007/s10853-008-2802-z PG 10 WC Materials Science, Multidisciplinary SC Materials Science GA 355UC UT WOS:000259733500025 ER PT J AU Rinsland, CP Devi, VM Blake, TA Sams, RL Sharpe, S Chiou, L AF Rinsland, C. P. Devi, V. Malathy Blake, Thomas A. Sams, R. L. Sharpe, Steven Chiou, Linda TI Quantitative measurement of integrated band intensities of benzene vapor in the mid-infrared at 278, 298, and 323 K SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article DE laboratory spectroscopy; infrared; C6H6; absorption cross section; planetary atmospheres; titan; Jupiter; Saturn; remote sounding; Fourier transform infrared (FTIR) spectroscopy; transmission and scattering of radiation ID DIODE-LASER SPECTROSCOPY; UPPER-ATMOSPHERE; TITAN; DATABASE; SPECTRA; REGION; C6H6 AB Pressure broadened (1 atm. N-2) laboratory spectra of benzene vapor (in natural abundance) were recorded at 278, 298, and 323 K, covering 600-6500cm(-1),. The spectra were recorded at a resolution of 0.112cm(-1) using a commercial Fourier transform spectrometer. The pressure of each benzene vapor sample was measured using high-precision capacitance manometers, and a minimum,1111 of nine sample pressures were recorded for each temperature. The samples were introduced into the temperature-stabilized static cell (19.94(l) cm pathlength) that was hard-mounted into the spectremeter. Front these data a fit composite Spectrum was calculated for each temperature. The number density for the three composite spectra was normalized to 296 K. The spectra give the absorption coefficient (cm(2) molecule(-1), naperian units) as a function of wavenumber. From these spectra integrated band intensities (cm molecule(-1) and atm(-1) cm(-2)) for intervals corresponding to the stronger benzene bands were calculated and were compared with previously reported values. We discuss and quantify error Sources and estimate Our systematic (NIST Type-B) errors to be 3% for the stronger bands. The measured absorption coefficients and integrated band intensities are useful for remote sensing applications such as measurements of planetary atmospheres and assessment of the environmental impact of terrestrial oil fire emissions. (C) 2008 Elsevier Ltd. All rights reserved. C1 [Rinsland, C. P.] NASA, Langley Res Ctr, Sci Directorate, Hampton, VA 23681 USA. [Devi, V. Malathy] Coll William & Mary, Dept Phys, Williamsburg, VA 23187 USA. [Blake, Thomas A.; Sams, R. L.; Sharpe, Steven] Pacific NW Natl Lab, Richland, WA 99352 USA. [Chiou, Linda] Sci Syst & Applicat Inc, Hampton, VA 23666 USA. RP Rinsland, CP (reprint author), NASA, Langley Res Ctr, Sci Directorate, Mail Stop 401A, Hampton, VA 23681 USA. EM curtis.p.rinsland@nasa.gov; malathy.d.venkataraman@nasa.gov; ta.blake@pnl.gov; robert.sams@pnl.gov; sw.sharpe@pnl.gov; l.s.chiou@larc.nasa.gov FU United States Department of Energy; Battelle Memorial Institute [DE-AC05-76RLO 1830]; NASA Langley Research Center; College of William and Mary FX The experimental work for this paper was performed at the W.R. Wiley Environmental Molecular Sciences Laboratory, a national scientific user facility sponsored by the Department of Energy's Office of Biological and Environmental Research and located at Pacific Northwest National Laboratory. PNNL is operated for the United States Department of Energy by the Battelle Memorial Institute under contract DE-AC05-76RLO 1830. NASA's planetary atmospheres program Supported the work performed at NASA Langley Research Center and the College of William and Mary. NR 37 TC 8 Z9 8 U1 2 U2 11 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 OCT PY 2008 VL 109 IS 15 BP 2511 EP 2522 DI 10.1016/j.jqsrt.2008.04.007 PG 12 WC Optics; Spectroscopy SC Optics; Spectroscopy GA 354TI UT WOS:000259661500002 ER PT J AU Hong, G Feng, Q Yang, P Kattawar, GW Minnis, P Hu, YX AF Hong, Gang Feng, Qian Yang, Ping Kattawar, George W. Minnis, Patrick Hu, Yong X. TI Optical properties of ice particles in young contrails SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article DE optical properties; ice particles; contrails ID VECTOR RADIATIVE-TRANSFER; DISCRETE-ORDINATE METHOD; SOLAR-RADIATION; CLOUD DROPLETS; BLACK CARBON; SCATTERING PROPERTIES; LIGHT-SCATTERING; COATED SPHERES; SOOT PARTICLES; TRANSFER MODEL AB The single-scattering properties of four types of ice crystals (pure ice crystals, ice crystals with ail internal mixture of ice and black carbon, ice crystals coated with black carbon, and soot coated with ice) in young contrails are investigated at wavelengths 0.65 and 2.13 mu m using Mic codes for coated Spheres. The four types of ice crystals show differences in their single-scattering properties because of the embedded black carbon whose volume ratio is assumed to be 5%. The bulk-scattering properties of young contrails consisting of the four types Of ice crystals are further investigated by averaging their single-scattering properties over a typical ice particle size distribution found in young contrails. The effect of the radiative properties of the four types of ice particles on the Stokes parameters 1, Q U, and V is also investigated for different viewing zenith angles and relative azimuth angles with a solar zenith angle of 30 degrees using a vector radiative transfer model based on the adding-doubling technique. The Stokes parameters at a wavelength of 0.65 mu m show pronounced differences for the four types of ice crystals, whereas the counterparts at a wavelength of 2.13 mu m show similar variations with the viewing zenith angle and relative azimuth angle. However, the values of the results for the two wavelengths are noticeably different. (C) 2008 Elsevier Ltd. All rights reserved. C1 [Hong, Gang; Feng, Qian; Yang, Ping; Kattawar, George W.] Texas A&M Univ, Dept Atmospher Sci, College Stn, TX 77843 USA. [Minnis, Patrick; Hu, Yong X.] NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Hong, G (reprint author), Texas A&M Univ, Dept Atmospher Sci, College Stn, TX 77843 USA. EM hong@ariel.met.tamu.edu RI Minnis, Patrick/G-1902-2010; Yang, Ping/B-4590-2011; Hong, Gang/A-2323-2012; Hu, Yongxiang/K-4426-2012 OI Minnis, Patrick/0000-0002-4733-6148; NR 59 TC 8 Z9 9 U1 0 U2 0 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 OCT PY 2008 VL 109 IS 15 BP 2635 EP 2647 DI 10.1016/j.jqsrt.2008.06.005 PG 13 WC Optics; Spectroscopy SC Optics; Spectroscopy GA 354TI UT WOS:000259661500012 ER PT J AU Liu, L Mishchenko, MI Arnott, WP AF Liu, Li Mishchenko, Michael I. Arnott, W. Patrick TI A study of radiative properties of fractal soot aggregates using the superposition T-matrix method SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article DE soot aggregates; absorption class section; scattering cross section; extinction class section; single-scattering albedo; asymmetry parameter; fractal dimension ID LIGHT-SCATTERING; REFERENCE DATABASE; CARBONACEOUS PARTICLES; SPHERE CLUSTERS; SOUTHERN AFRICA; SMOKE; ABSORPTION; AEROSOLS; UPDATE; OPTICS AB We employ the numerically exact superposition T-matrix method to perform extensive computations of scattering and absorption properties of soot aggregates with varying state of compactness and size. The fractal dimension, of, is used to quantify the geometrical mass dispersion of the clusters. The optical properties of soot aggregates for a given fractal dimension are complex functions of the refractive index of the material in, the number of monomers N-s, and the monomer radius a. It is shown that for smaller values of 0, the absorption cross section tends to be relatively constant when D-f < 2 but increases rapidly when D-f > 2. However, a systematic reduction in light absorption with of is observed for clusters with sufficiently large N-s, m, and a. The scattering cross section and single-scattering albedo increase monotonically as fractals evolve front chain-like to more densely packed morphologies, which is a strong manifestation of the increasing importance of scattering interaction among spherules. Overall, the results for soot fractals differ profoundly from those calculated for the respective volume-equivalent soot spheres as well as for the respective external mixtures of soot monomers under tire assumption that there are no electromagnetic interactions between the monomers. The climate-research implications Of our results are discussed. Published by Elsevier Ltd. C1 [Liu, Li; Mishchenko, Michael I.] NASA, Goddard Inst Space Studies, New York, NY 10025 USA. [Liu, Li] Columbia Univ, Dept Appl Phys & Appl Math, New York, NY 10025 USA. [Arnott, W. Patrick] Univ Nevada Reno, Dept Phys, Reno, NV 89557 USA. RP Mishchenko, MI (reprint author), NASA, Goddard Inst Space Studies, 2880 Broadway, New York, NY 10025 USA. EM crmim@giss.nasa.gov RI Mishchenko, Michael/D-4426-2012 NR 25 TC 102 Z9 108 U1 12 U2 29 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 OCT PY 2008 VL 109 IS 15 BP 2656 EP 2663 DI 10.1016/j.jqsrt.2008.05.001 PG 8 WC Optics; Spectroscopy SC Optics; Spectroscopy GA 354TI UT WOS:000259661500014 ER PT J AU Datta, A Chopra, I AF Datta, Anubhav Chopra, Inderjit TI Prediction of the UH-60A Main Rotor Structural Loads Using Computational Fluid Dynamics/Comprehensive Analysis Coupling SO JOURNAL OF THE AMERICAN HELICOPTER SOCIETY LA English DT Article; Proceedings Paper CT 32nd European Rotorcraft Forum CY SEP, 2006 CL Maastricht, NETHERLANDS ID VIBRATORY LOADS; HIGH-SPEED; AIRLOADS; FLIGHT; SIMULATIONS; VALIDATION; HELICOPTER; DYNAMICS; FIELD; MODEL AB This paper predicts the UH-60A main rotor structural loads using computational fluid dynamics (CFD) and computational structural dynamics (CSD) coupling at three important level flight conditions. The accuracy of the CSD model by itself is studied by using the flight test measured airloads, lag damper force, and control angles. The CFD/CSD predictions are then compared with flight test data and with predictions from measured airloads. The three flight conditions are each characterized by three different aerodynamic phenomena: wake-induced inflow at low speed, unsteady transonic pitching moments at high speed, and multiple dynamic stall cycles at a highly loaded flight. Each flight is also characterized by three different structural dynamic phenomena: 3/rev flap bending at low speed, low-frequency elastic twist (1 and 2/rev) at high speed. and high-frequency elastic twist (4 and 5/rev) at stall. The predicted flap bending moments show upto 50% underprediction of 3/rev magnitude at low speed, satisfactory prediction at high speed, and a 3/rev phase error in the stall flight. This problem appears to stem from the predicted airloads. The predicted torsion loads are satisfactory upto 3/rev. The 4/rev and higher harmonics show significant discrepancies (up to 50% error with test data). This problem appears to stem from structural dynamics. The predicted chord bending moments show significant discrepancies in the magnitudes of 4 and 5/rev harmonics. On average, the 4/rev is underpredicted by 50% and the 5/rev is overpredicted by 50% along the span. This problem also appears to stem from structural dynamics. C1 [Datta, Anubhav] NASA, Ames Res Ctr, ELORET Corp, Moffett Field, CA 94035 USA. [Chopra, Inderjit] Univ Maryland, Dept Aerosp Engn, Alfred Gessow Rotorcraft Ctr, College Pk, MD 20742 USA. RP Datta, A (reprint author), NASA, Ames Res Ctr, ELORET Corp, Moffett Field, CA 94035 USA. EM datta@umd.edu NR 30 TC 7 Z9 8 U1 0 U2 1 PU AMER HELICOPTER SOC INC PI ALEXANDRIA PA 217 N WASHINGTON ST, ALEXANDRIA, VA 22314 USA SN 0002-8711 J9 J AM HELICOPTER SOC JI J. Am. Helicopter Soc. PD OCT PY 2008 VL 53 IS 4 BP 351 EP 365 PG 15 WC Engineering, Aerospace SC Engineering GA 369YZ UT WOS:000260731100003 ER PT J AU Herrero, FA Jones, HH Lee, JG AF Herrero, Federico A. Jones, Hollis H. Lee, Jeffrey G. TI The Gated Electrostatic Mass Spectrometer (GEMS): Definition and Preliminary Results SO JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY LA English DT Article AB GEMS is a new type of time-of-flight mass spectrometer based on an electrostatic energy analyzer. Mass resolution equals the energy analyzer kinetic energy resolution, which is set by its slit size. In GEMS, monochromatic ions enter the entrance slit at random times, and the gated ion deflection produced by the electrostatic field in the analyzer rejects ions that are inside the analyzer at gate onset, detecting those entering the analyzer after gate onset. This provides mass separation while overcoming the temporal and spatial spread problems typical of TOE applications. Paradoxically, GEMS works because all ion masses follow identical trajectories. GEMS is easily multiplied into two-dimensional arrays to increase sensitivity in space applications, requires relatively low voltages, and uses only a few electrical connections. Thus, it is easy to package GEMS as a small, low-power instrument for applications in harsh environments. A disadvantage of GEMS is that its output is the integral of the TOF spectrum and the derivative of the raw data Must be taken, a procedure that is likely to add noise. A version of GEMS detecting un-deflected ions (u-GEMS) has been tested to demonstrate the dine-integrated feature of the raw data but without the benefit of energy analysis. This paper describes GEMS implemented with the small deflection energy analyzer (SDEA), a compact version of the parallel plate energy analyzer. SDEA is described both analytically and with ion trajectory simulations using the ion trajectory Simulation software SIMION; the results are then used to describe GEMS and compute its performance. (J Am Soc Mass Spectrom 2008, 19, 1384-1394) (C) 2008 Published by Elsevier Inc. on behalf of American Society for Mass Spectrometry C1 [Herrero, Federico A.; Jones, Hollis H.; Lee, Jeffrey G.] NASA, Goddard Space Flight Ctr, Detector Syst Branch, Greenbelt, MD 20771 USA. RP Herrero, FA (reprint author), NASA, Goddard Space Flight Ctr, Detector Syst Branch, Code 553, Greenbelt, MD 20771 USA. EM Fred.Herrero@nasa.gov NR 28 TC 3 Z9 3 U1 0 U2 4 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 1044-0305 J9 J AM SOC MASS SPECTR JI J. Am. Soc. Mass Spectrom. PD OCT PY 2008 VL 19 IS 10 BP 1384 EP 1394 DI 10.1016/j.jasms.2008.07.014 PG 11 WC Chemistry, Analytical; Chemistry, Physical; Spectroscopy SC Chemistry; Spectroscopy GA 363LJ UT WOS:000260268500003 PM 18718764 ER PT J AU Griffin, TP Diaz, JA Arkin, CR Soto, C Curley, CH Gomez, O AF Griffin, Timothy P. Diaz, Jorge Andres Arkin, C. Richard Soto, Carlomagno Curley, Charles H. Gomez, Oliver TI Three-Dimensional Concentration Mapping of Gases using a Portable Mass Spectrometer System SO JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY LA English DT Article AB The visualization of hazardous gaseous emissions at volcanoes using in-situ mass spectrometry (MS) is a key step towards a better comprehension of the geophysical phenomena Surrounding eruptive activity. In-situ data consisting of helium, carbon dioxide, Sulfur dioxide, and other gas species, were acquired with a quadrupole based MS system. Global position systems (GPS) and MS data were plotted on ground imagery, topography, and remote sensing data collected by a host of instruments during the second Costa Rica Airborne Research and Technology Applications (CARTA) mission. This combination of gas and imaging data allowed three-dimensional (3D) visualization of the volcanic plume and the mapping of gas concentration at several volcanic structures and urban areas. This combined Set of data has demonstrated a better tool to assess hazardous conditions by visualizing and modeling of possible scenarios of volcanic activity. The MS system is used for in-situ measurement of 3D gas concentrations at different volcanic locations with three different transportation platforms: aircraft, auto, and hand-carried. The demonstration for urban contamination mapping is also presented as another possible use for the MS system. (J Am Soc Mass Spectrom 2008, 19, 1411-1418) (C) 2008 American Society for Mass Spectrometry C1 [Griffin, Timothy P.] NASA, Kennedy Space Ctr, FL 32815 USA. [Diaz, Jorge Andres] Univ Costa Rica, CICANUM, Sch Phys, San Jose, Costa Rica. [Arkin, C. Richard; Curley, Charles H.] ASRC Aerosp Corp, Kennedy Space Ctr, FL USA. [Soto, Carlomagno; Gomez, Oliver] PRIAS CENAT, Natl Program Airborne Res, San Jose, Costa Rica. RP Griffin, TP (reprint author), NASA, NE-L2, Kennedy Space Ctr, FL 32815 USA. EM Timothy.P.Griffin@NASA.gov RI Soto Castro, Carlomagno/G-6510-2014 OI Soto Castro, Carlomagno/0000-0002-1916-9549 NR 16 TC 8 Z9 8 U1 0 U2 7 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 1044-0305 J9 J AM SOC MASS SPECTR JI J. Am. Soc. Mass Spectrom. PD OCT PY 2008 VL 19 IS 10 BP 1411 EP 1418 DI 10.1016/j.jasms.2008.05.020 PG 8 WC Chemistry, Analytical; Chemistry, Physical; Spectroscopy SC Chemistry; Spectroscopy GA 363LJ UT WOS:000260268500006 PM 18620866 ER PT J AU Parker, JS Born, GH AF Parker, Jeffrey S. Born, George H. TI Direct Lunar Halo Orbit Transfers SO JOURNAL OF THE ASTRONAUTICAL SCIENCES LA English DT Article ID PERIODIC ORBITS; MISSION; DESIGN AB This paper provides a robust survey of short-duration, two-bum transfers from the Earth to lunar halo orbits. The results show that several families of such transfers exist, including quick four- to five-day transfers, as well as more efficient transfers that require three or more weeks. The trajectories surveyed in this paper all begin from 185-km circular Earth parking orbits, with varying inclinations; they transfer to many sample halo orbits about the Earth-Moon L(1) and L(2) points. It has been found that the quickest lunar transfers require between 3.6 and 4.1 km/s, depending on the halo orbit destination. If more time is available, then any lunar halo orbit considered in this paper may be reached for as little as 3.59 to 3.65 km/s. Finally, the paper discusses the costs and benefits of short and longer halo transfers applied to real lunar mission designs. C1 [Parker, Jeffrey S.; Born, George H.] Univ Colorado, Colorado Ctr Astrodynam Res, Boulder, CO 80309 USA. RP Parker, JS (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. FU National Aeronautics and Space Administration through the Jet Propulsion Laboratory, California Institute of Technology FX This work has been completed under funding by a NASA Graduate Student Researchers Program (GSRP) Fellowship by the National Aeronautics and Space Administration through the Jet Propulsion Laboratory, California Institute of Technology. NR 27 TC 4 Z9 5 U1 0 U2 3 PU AMER ASTRONAUTICAL SOC PI SPRINGFIELD PA 6352 ROLLING MILL PLACE SUITE 102, SPRINGFIELD, VA 22152 USA SN 0021-9142 J9 J ASTRONAUT SCI JI J. Astronaut. Sci. PD OCT-DEC PY 2008 VL 56 IS 4 BP 441 EP 476 PG 36 WC Engineering, Aerospace SC Engineering GA 538VM UT WOS:000273212300001 ER PT J AU Jiang, X Pawson, S Camp, CD Nielsen, JE Shia, RL Liao, T Limpasuvan, V Yung, YL AF Jiang, Xun Pawson, Steven Camp, Charles D. Nielsen, J. Eric Shia, Run-Lie Liao, Ting Limpasuvan, Varavut Yung, Yuk L. TI Interannual variability and trends of extratropical ozone. Part I: Northern Hemisphere SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID PLANETARY-WAVES; STRATOSPHERIC WARMINGS; REANALYSIS PROJECT; ERA-40 REANALYSIS; POLAR VORTEX; GLOBAL QBO; CIRCULATION; MODEL; CLIMATOLOGY; SIMULATIONS AB The authors apply principal component analysis (PCA) to the extratropical total column ozone from the combined merged ozone data product and the European Centre for Medium-Range Weather Forecasts assimilated ozone from January 1979 to August 2002. The interannual variability (IAV) of extratropical O-3 in the Northern Hemisphere (NH) is characterized by four main modes. Attributable to dominant dynamical effects, these four modes account for nearly 60% of the total ozone variance in the NH. The patterns of variability are distinctly different from those derived for total O-3 in the tropics. To relate the derived patterns of O-3 to atmospheric dynamics, similar decompositions are performed for the 30 100-hPa geopotential thickness. The results reveal intimate connections between the IAV of total ozone and the atmospheric circulation. The first two leading modes are nearly zonally symmetric and represent the connections to the annular modes and the quasi-biennial oscillation. The other two modes exhibit in-quadrature, wavenumber-1 structures that, when combined, describe the displacement of the polar vortices in response to planetary waves. In the NH, the extrema of these combined modes have preferred locations that suggest fixed topographical and land-sea thermal forcing of the involved planetary waves. Similar spatial patterns and trends in extratropical column ozone are simulated by the Goddard Earth Observation System chemistry-climate model (GEOS-CCM). The decreasing O-3 trend is captured in the first mode. The largest trend occurs at the North Pole, with values similar to-1 Dobson Unit (DU) yr(-1). There is almost no trend in tropical O-3. The trends derived from PCA are confirmed using a completely independent method, empirical mode decomposition, for zonally averaged O-3 data. The O-3 trend is also captured by mode 1 in the GEOS-CCM, but the decrease is substantially larger than that in the real atmosphere. C1 [Jiang, Xun; Shia, Run-Lie; Yung, Yuk L.] CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. [Pawson, Steven; Nielsen, J. Eric] NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Greenbelt, MD 20771 USA. [Camp, Charles D.] Calif Polytech State Univ San Luis Obispo, Dept Math, San Luis Obispo, CA 93407 USA. [Nielsen, J. Eric] Sci Syst & Applicat Inc, Lanham, MD USA. [Liao, Ting] CALTECH, Dept Phys, Pasadena, CA 91125 USA. [Limpasuvan, Varavut] Coastal Carolina Univ, Dept Chem & Phys, Conway, SC USA. RP Yung, YL (reprint author), CALTECH, Div Geol & Planetary Sci, 1200 E Calif Blvd, Pasadena, CA 91125 USA. EM yly@gps.caltech.edu RI Limpasuvan, Varavut/K-6266-2013; Pawson, Steven/I-1865-2014 OI Pawson, Steven/0000-0003-0200-717X FU NASA [NNG04GD76G, NNG04GN02G]; NASA's Modeling and Analysis Program; NSF [ATM-0213248, ATM-0521002] FX We thank D. E. Waliser, M. Allen, D. Feldman, A. Ingersoll, J. Perkins, J. Weibel, M. Gerstell, and two anonymous reviewers for useful inputs and helpful comments. Special thanks are due to R. Stolarski for his contribution to the ozone simulations, K. Jeev for deducing the missing O3 data using potential vorticity, L. M. Li for critical reading and editing of the manuscript, and R. Salawitch for improving presentation of results on O3 trends. NASA provided computational resources for running the GEOS-CCM through their high-performance computing initiative (the model was run on the "Columbia" computer at NASA Ames Research Center) This research was supported in part by NASA Grants NNG04GD76G and NNG04GN02G to the California Institute of Technology. S. Pawson and E. Nielsen were supported by NASA's Modeling and Analysis Program. V. Limpasuvan was supported by NSF Grants ATM-0213248 and ATM-0521002. NR 56 TC 13 Z9 15 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 OCT PY 2008 VL 65 IS 10 BP 3013 EP 3029 DI 10.1175/2008JAS2665.1 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 357BS UT WOS:000259821900001 ER PT J AU Jiang, X Pawson, S Camp, CD Nielsen, JE Shia, RL Liao, T Limpasuvan, V Yung, YL AF Jiang, Xun Pawson, Steven Camp, Charles D. Nielsen, J. Eric Shia, Run-Lie Liao, Ting Limpasuvan, Varavut Yung, Yuk L. TI Interannual variability and trends of extratropical ozone. Part II: Southern Hemisphere SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID REANALYSIS PROJECT; ERA-40 REANALYSIS; MODEL SIMULATIONS; CLIMATE-CHANGE; ANNULAR MODES; GLOBAL QBO; CIRCULATION; CHEMISTRY; IMPACT; LAYER AB A principal component analysis (PCA) is applied to the Southern Hemisphere (SH) total column ozone following the method established for analyzing the data in the Northern Hemisphere (NH) in a companion paper. The interannual variability (IAV) of extratropical O-3 in the SH is characterized by four main modes, which account for 75% of the total variance. The first two leading modes are approximately zonally symmetric and relate to the Southern Hemisphere annular mode and the quasi-biennial oscillation. The third and fourth modes exhibit wavenumber-1 structures. Contrary to the Northern Hemisphere, the third and fourth modes are not related to stationary waves. Similar results are obtained for the 30 100-hPa geopotential thickness. The decreasing O3 trend in the SH is captured in the first mode. The largest trend is at the South Pole, with value similar to-2 Dobson Units (DU) yr(-1). Both the spatial pattern and trends in the column ozone are captured by the Goddard Earth Observation System chemistry-climate model (GEOS-CCM) in the SH. C1 [Jiang, Xun; Shia, Run-Lie; Yung, Yuk L.] CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. [Pawson, Steven; Nielsen, J. Eric] NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Greenbelt, MD 20771 USA. [Camp, Charles D.] Calif Polytech State Univ San Luis Obispo, Dept Math, San Luis Obispo, CA 93407 USA. [Nielsen, J. Eric] Sci Syst & Applicat Inc, Lanham, MD USA. [Liao, Ting] CALTECH, Dept Phys, Pasadena, CA 91125 USA. [Limpasuvan, Varavut] Coastal Carolina Univ, Dept Chem & Phys, Conway, SC USA. RP Yung, YL (reprint author), CALTECH, Div Geol & Planetary Sci, 1200 E Calif Blvd, Pasadena, CA 91125 USA. EM yly@gps.caltech.edu RI Limpasuvan, Varavut/K-6266-2013; Pawson, Steven/I-1865-2014 OI Pawson, Steven/0000-0003-0200-717X FU NASA [NNG04GD76G, NNG04GN02G]; NASA's Modeling and Analysis Program; NSF [ATM-0213248, ATM-0521002] FX We thank D. E. Waliser, M. Allen, D. Feldman, A. Ingersoll, J. Perkins, J. Weibel, M. Gerstell, and two anonymous reviewers for useful inputs and helpful comments. Special thanks are due to R. Stolarski for his contribution to the ozone simulations, K. Jeev for deducing the missing O3 data using potential vorticity, L. M. Li for critical reading and editing of the manuscript, and R. Salawitch for improving presentation of results on O3 trends. NASA provided computational resources for running the GEOS-CCM through their high-performance computing initiative ( the model was run on the "Columbia" computer at NASA Ames Research Center). This research was supported in part by NASA Grants NNG04GD76G and NNG04GN02G to the California Institute of Technology. S. Pawson and E. Nielsen were supported by NASA's Modeling and Analysis Program. V. Limpasuvan was supported by NSF Grants ATM-0213248 and ATM-0521002. NR 41 TC 13 Z9 13 U1 0 U2 4 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 OCT PY 2008 VL 65 IS 10 BP 3030 EP 3041 DI 10.1175/2008JAS2793.1 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 357BS UT WOS:000259821900002 ER PT J AU Evans, KF Marshak, A Varnai, T AF Evans, K. Franklin Marshak, Alexander Varnai, Tamas TI The potential for improved boundary layer cloud optical depth retrievals from the multiple directions of MISR SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID INDEPENDENT PIXEL APPROXIMATION; RADIATIVE-TRANSFER; IMAGING SPECTRORADIOMETER; SHALLOW CUMULUS; STRATOCUMULUS; THICKNESS; SIMULATIONS; RESOLUTION; ACCURACY; RADIANCE AB The Multiangle Imaging Spectroradiometer (MISR) views the earth with nine cameras, ranging from a 70 zenith angle viewing forward through nadir to 70 viewing aft. MISR does not have an operational cloud optical depth retrieval algorithm, but previous research has hinted that solar reflection measured in multiple directions might improve cloud optical depth retrievals. This study explores the optical depth information content of MISR's multiple angles using a retrieval simulation approach. Hundreds of realistic boundary-layer cloud fields are generated with large-eddy simulation (LES) models for stratocumulus, small trade cumulus, and land surface forced fair-weather cumulus. Reflectances in MISR directions are computed with three-dimensional radiative transfer from the LES cloud fields over an ocean surface and averaged to MISR resolution and sampled at MISR 275-m pixel spacing. Neural networks are trained to retrieve the mean and standard deviation of optical depth over different size pixel patches from the mean and standard deviation of simulated MISR reflectances. Various configurations of MISR cameras are input to the retrieval, and the rms retrieval errors are compared. For 5 x 5 pixel patches the already low mean optical depth retrieval error for stratocumulus decreases 41% and 23% (for 25 degrees and 45 degrees solar zenith angles, respectively) from using only the nadir camera to using seven MISR cameras. For cumulus, however, the much higher normalized optical depth retrieval error only decreases around 14%. These small improvements suggest that measurements of solar reflection in multiple directions do not contribute substantially to more accurate optical depth retrievals for small cumulus clouds. The 3D statistical retrievals, however, even with only the nadir camera, are much more accurate for small cumulus than standard nadir plane-parallel retrievals; therefore, this approach may be worth pursuing. C1 [Evans, K. Franklin] Univ Colorado, Boulder, CO 80309 USA. [Marshak, Alexander] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Varnai, Tamas] Univ Maryland Baltimore Cty, Joint Ctr Earth Syst Technol, Baltimore, MD 21228 USA. RP Evans, KF (reprint author), Univ Colorado, 311 UCB, Boulder, CO 80309 USA. EM evans@nit.colorado.edu RI Marshak, Alexander/D-5671-2012 FU NASA Radiation Sciences Program [621-30-86, 622-42-57] FX We are very grateful to Andrew Ackerman for providing the stratocumulus fields in a form tailored for us and for providing comments on the manuscript. We are grateful to Bjorn Stevens for providing his UCLA LES code. We thank Robert Pincus for providing the land cumulus LES scenes. We also thank Bob Cahalan for his support and encouragement. This research was supported by the NASA Radiation Sciences Program under Grants 621-30-86 and 622-42-57. NR 40 TC 8 Z9 8 U1 0 U2 8 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 OCT PY 2008 VL 65 IS 10 BP 3179 EP 3196 DI 10.1175/2008JAS2627.1 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 357BS UT WOS:000259821900010 ER PT J AU Oman, L Waugh, DW Pawson, S Stolarski, RS Nielsen, JE AF Oman, Luke Waugh, Darryn W. Pawson, Steven Stolarski, Richard S. Nielsen, J. Eric TI Understanding the changes of stratospheric water vapor in coupled Chemistry-Climate Model simulations SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID TRANSPORT; INCREASE; HCL; AIR AB Past and future climate simulations from the Goddard Earth Observing System Chemistry-Climate Model (GEOS CCM), with specified boundary conditions for sea surface temperature, sea ice, and trace gas emissions, have been analyzed to assess trends and possible causes of changes in stratospheric water vapor. The simulated distribution of stratospheric water vapor in the 1990s compares well with observations. Changes in the cold point temperatures near the tropical tropopause can explain differences in entry stratospheric water vapor. The average saturation mixing ratio of a 20 latitude by 15 longitude region surrounding the minimum tropical saturation mixing ratio is shown to be a useful diagnostic for entry stratospheric water vapor and does an excellent job reconstructing the annual average entry stratospheric water vapor over the period 1950-2100. The simulated stratospheric water vapor increases over the 50 yr between 1950 and 2000, primarily because of changes in methane concentrations, offset by a slight decrease in tropical cold point temperatures. Stratospheric water vapor is predicted to continue to increase over the twenty-first century, with increasing methane concentrations causing the majority of the trend to midcentury. Small increases in cold point temperature cause increases in the entry water vapor throughout the twenty-first century. The increasing trend in future water vapor is tempered by a decreasing contribution of methane oxidation owing to cooling stratospheric temperatures and by increased tropical upwelling, leading to a near-zero trend for the last 30 yr of the twenty-first century. C1 [Oman, Luke; Waugh, Darryn W.] Johns Hopkins Univ, Dept Earth & Planetary Sci, Baltimore, MD 21218 USA. [Pawson, Steven; Nielsen, J. Eric] NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Greenbelt, MD 20771 USA. [Stolarski, Richard S.] NASA, Goddard Space Flight Ctr, Atmospher Chem & Dynam Branch, Greenbelt, MD 20771 USA. RP Oman, L (reprint author), Johns Hopkins Univ, Dept Earth & Planetary Sci, 301 Olin Bldg,3400 N Charles St, Baltimore, MD 21218 USA. EM oman@jhu.edu RI Oman, Luke/C-2778-2009; Stolarski, Richard/B-8499-2013; Pawson, Steven/I-1865-2014; Waugh, Darryn/K-3688-2016 OI Oman, Luke/0000-0002-5487-2598; Stolarski, Richard/0000-0001-8722-4012; Pawson, Steven/0000-0003-0200-717X; Waugh, Darryn/0000-0001-7692-2798 FU NASA's MAP Program FX We thank Paul Newman and Anne Douglass for their helpful comments and suggestions and Stacey Frith for helping with the data processing. Thanks to Stefan Fueglistaler and two anonymous reviewers for their helpful comments on improving this manuscript. We also appreciate Don Anderson of NASA's MAP Program for funding, those involved in model development at GSFC, and high-performance computing resources on NASA's "Project Columbia." NR 27 TC 22 Z9 22 U1 0 U2 0 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 OCT PY 2008 VL 65 IS 10 BP 3278 EP 3291 DI 10.1175/2008JAS2696.1 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 357BS UT WOS:000259821900016 ER PT J AU Errico, RM Bauer, P Mahfouf, JF AF Errico, Ronald M. Bauer, Peter Mahfouf, Jean-Francois TI Comments on "Issues Regarding the Assimilation of Cloud and Precipitation Data" - Reply SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Editorial Material AB This is a reply to a set of criticisms regarding a previously published work. It briefly addresses the main criticisms. In particular, it explains why some papers identified as having some fundamental flaws were referenced in the original work without detailed exposition of those flaws. It also explains why parts of the conclusions criticized as being contradictory are, in fact, not. It further highlights the need for more publishing of scientific criticisms. C1 [Errico, Ronald M.] NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Greenbelt, MD 20771 USA. [Errico, Ronald M.] Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21228 USA. [Bauer, Peter] European Ctr Medium Range Weather Forecasts, Reading RG2 9AX, Berks, England. [Mahfouf, Jean-Francois] Meteo France, Toulouse, France. RP Errico, RM (reprint author), NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Code 610-1, Greenbelt, MD 20771 USA. EM ronald.m.errico@nasa.gov NR 7 TC 1 Z9 1 U1 0 U2 3 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 OCT PY 2008 VL 65 IS 10 BP 3348 EP 3350 DI 10.1175/2008JAS2817.1 PG 3 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 357BS UT WOS:000259821900023 ER PT J AU Fischer, DG Prahl, SA Duncan, DD AF Fischer, David G. Prahl, Scott A. Duncan, Donald D. TI Monte Carlo modeling of spatial coherence: free-space diffraction SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION LA English DT Article ID BACKSCATTERING MUELLER MATRIX; POLARIZED-LIGHT TRANSPORT; HIGHLY SCATTERING MEDIA; TURBID MEDIA; OPTICAL-PROPERTIES; TOMOGRAPHY; BEAMS; SIMULATION; SIGNAL; DISTRIBUTIONS AB We present a Monte Carlo method for propagating partially coherent fields through complex deterministic optical systems. A Gaussian copula is used to synthesize a random source with an arbitrary spatial coherence function. Physical optics and Monte Carlo predictions of the first- and second-order statistics of the field are shown for coherent and partially coherent sources for free-space propagation, imaging using a binary Fresnel zone plate, and propagation through a limiting aperture. Excellent agreement between the physical optics and Monte Carlo predictions is demonstrated in all cases. Convergence criteria are presented for judging the quality of the Monte Carlo predictions. (C) 2008 Optical Society of America C1 [Fischer, David G.] NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. [Prahl, Scott A.] Providence St Vincent Med Ctr, Oregon Med Laser Ctr, Portland, OR 97225 USA. [Duncan, Donald D.] Oregon Hlth & Sci Univ, Dept Biomed Engn, Portland, OR 97239 USA. RP Fischer, DG (reprint author), NASA, Glenn Res Ctr, 21000 Brookpk Rd, Cleveland, OH 44135 USA. EM cdfischer@roadrunner.com FU National institutes of Health (NIH) [CA103824] FX This work was sponsored in part by National institutes of Health (NIH) grant CA103824. NR 40 TC 14 Z9 14 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 OCT PY 2008 VL 25 IS 10 BP 2571 EP 2581 DI 10.1364/JOSAA.25.002571 PG 11 WC Optics SC Optics GA 371QN UT WOS:000260846400020 PM 18830335 ER PT J AU Doran, PT Fritsen, CH Murray, AE Kenig, F Mckay, CP Kyne, JD AF Doran, Peter T. Fritsen, Christian H. Murray, Alison E. Kenig, Fabien Mckay, Chris P. Kyne, Jay D. TI Entry approach into pristine ice-sealed lakes - Lake Vida, East Antarctica, a model ecosystem SO LIMNOLOGY AND OCEANOGRAPHY-METHODS LA English DT Article ID SUBGLACIAL LAKES; CARBON; COVER AB Ice-sealed lakes, potentially home to novel microbiota and microbial processes, can provide a window into isolated and geologically ancient systems. These habitats are earth analogs for extraterrestrial systems that have yet to be sampled, though potentially harbor, or have harbored life at some time during their past. They are also small-scale models of the numerous sub-glacial lake systems, which have been identified across Antarctica and in Iceland. Methods are needed to sample these ecosystems with environmental stewardship in mind, in which human impact on the ecosystem is mitigated before and during sampling. This report describes an entry and sampling approach that was executed at Lake Vida, East Antarctica, a permanently ice-sealed lake that has never been sampled. Best practice sampling procedures were developed with emphasis on mitigating introduction of trace organics or microbiota to the ecosystem. The conceptual approach is transferable to other isolated pristine aquatic ecosystems on Earth and elsewhere. C1 [Doran, Peter T.; Kenig, Fabien] Univ Illinois, Dept Earth & Environm Sci, Chicago, IL 60607 USA. [Fritsen, Christian H.; Murray, Alison E.] Desert Res Inst, Div Earth & Ecosyst Sci, Reno, NV 89512 USA. [Mckay, Chris P.] NASA, Ames Res Ctr, Moffett Field, CA USA. [Kyne, Jay D.] Univ Wisconsin, Space Sci & Engn Ctr, Ice Coring & Drilling Serv, Madison, WI 53706 USA. RP Doran, PT (reprint author), Univ Illinois, Dept Earth & Environm Sci, Chicago, IL 60607 USA. EM pdoran@uic.edu RI Kenig, Fabien/A-4961-2008; OI Kenig, Fabien/0000-0003-4868-5232 FU National Aeronautics and Space Administration's (NASA) Astrobiology Science and Technology [NAG5-12889]; National Science Foundation's Office; Raytheon Polar Services; Petroleum Helicopter Inc FX This study was supported by the National Aeronautics and Space Administration's (NASA) Astrobiology Science and Technology for Exploring Planets program (grant NAG5-12889). Logistical support was provided by the National Science Foundation's Office of Polar Programs through a co-operative agreement with NASA. We thank Raytheon Polar Services and Petroleum Helicopter Inc. for providing support in the field and field team members P. Glenday, M. Badescu, S. Sherrit, N. Bramall, B. Bergeron, and C. Davis. We also appreciate the comments of an anonymous international panel that reviewed our field sampling plan prior to Antarctic deployment. NR 17 TC 14 Z9 14 U1 0 U2 17 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 OCT PY 2008 VL 6 BP 542 EP 547 PG 6 WC Limnology; Oceanography SC Marine & Freshwater Biology; Oceanography GA 378WH UT WOS:000261354800005 ER PT J AU Castano, A Fukunaga, A Biesiadecki, J Neakrase, L Whelley, P Greeley, R Lemmon, M Castano, R Chien, S AF Castano, Andres Fukunaga, Alex Biesiadecki, Jeffrey Neakrase, Lynn Whelley, Patrick Greeley, Ronald Lemmon, Mark Castano, Rebecca Chien, Steve TI Automatic detection of dust devils and clouds on Mars SO MACHINE VISION AND APPLICATIONS LA English DT Article DE surveillance; science; rover; MER ID EXPLORATION ROVERS; VIDEO AB The acquisition of science data in space applications is shifting from teleoperated data collection to an automated onboard analysis, resulting in improved data quality, as well as improved usage of limited resources such as onboard memory, CPU, and communications bandwidth. Science instruments onboard a modern deep-space spacecraft can acquire much more data that can be downloaded to Earth, given the limited communication bandwidth. Onboard data analysis offers a means of compressing the huge amounts of data collected and downloading only the most valuable subset of the collected data. In this paper, we describe algorithms for detecting dust devils and clouds onboard Mars rovers, and summarize the results. These algorithms achieve the accuracy required by planetary scientists, as well as the runtime, CPU, memory, and bandwidth constraints set by the engineering mission parameters. The detectors have been uploaded to the Mars Exploration Rovers, and currently are operational. These detectors are the first onboard science analysis processes on Mars. C1 [Castano, Andres; Fukunaga, Alex; Biesiadecki, Jeffrey; Castano, Rebecca; Chien, Steve] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Neakrase, Lynn; Whelley, Patrick; Greeley, Ronald] Arizona State Univ, Dept Geol Sci, Tempe, AZ 85287 USA. [Lemmon, Mark] Texas A&M Univ, Dept Atmospher Sci, College Stn, TX 77843 USA. RP Castano, A (reprint author), CALTECH, Jet Prop Lab, MS 125-209,4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Andres.Castano@jpl.nasa.gov RI Lemmon, Mark/E-9983-2010; Whelley, Patrick/B-9560-2012 OI Lemmon, Mark/0000-0002-4504-5136; Whelley, Patrick/0000-0003-3266-9772 FU NASA; Software Intelligent Systems and Modeling ( SISM); Mars Technology program (MTP); New Millennium Program (NMP) FX We thank Aaron Kiely for providing the ICER code used to estimate the compression ratios of masked detector products and Adnan Ansar for his help in characterizing the results of the difference of averages of the dust devil detector. The research 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. This work was supported by NASA as follows: algorithm prototyping and testing by the Software Intelligent Systems and Modeling ( SISM) program under the OASIS task, algorithm refinement and flight code integration by the Mars Technology program (MTP) under the MER On-board Science task and, further algorithm refinement and MER testing and operation by the New Millennium Program (NMP) under the MER Infusion Studies task. NR 27 TC 23 Z9 24 U1 0 U2 8 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0932-8092 EI 1432-1769 J9 MACH VISION APPL JI Mach. Vis. Appl. PD OCT PY 2008 VL 19 IS 5-6 BP 467 EP 482 DI 10.1007/s00138-007-0081-3 PG 16 WC Computer Science, Artificial Intelligence; Computer Science, Cybernetics; Engineering, Electrical & Electronic SC Computer Science; Engineering GA 354XE UT WOS:000259672400015 ER PT J AU Angrisani, L Moriello, RS D'Arco, M Greenhall, C AF Angrisani, Leopoldo Lo Moriello, Rosario Schiano D'Arco, Mauro Greenhall, Charles TI Optimal bandpass sampling strategies for enhancing the performance of a phase noise meter SO MEASUREMENT SCIENCE AND TECHNOLOGY LA English DT Article DE phase noise; phase noise measurement; quadrature demodulation; bandpass sampling; spectrum analyzer AB Measurement of phase noise affecting oscillators or clocks is a fundamental practice whenever the need of a reliable time base is of primary concern. In spite of the number of methods or techniques either available in the literature or implemented as personalities in general-purpose equipment, very accurate measurement results can be gained only through expensive, dedicated instruments. To offer a cost-effective alternative, the authors have already realized a DSP-based phase noise meter, capable of assuring good performance and real-time operation. The meter, however, suffers from a reduced frequency range (about 250 kHz), and needs an external time base for input signal digitization. To overcome these drawbacks, the authors propose the use of bandpass sampling strategies to enlarge the frequency range, and of an internal time base to make standalone operation much more feasible. After some remarks on the previous version of the meter, key features of the adopted time base and proposed sampling strategies are described in detail. Results of experimental tests, carried out on sinusoidal signals provided both by function and arbitrary waveform generators, are presented and discussed; evidence of the meter's reliability and efficacy is finally given. C1 [Angrisani, Leopoldo; Lo Moriello, Rosario Schiano] Univ Naples Federico II, Dipartimento Informat & Sistemist, I-80125 Naples, Italy. [D'Arco, Mauro] Univ Naples Federico II, Dipartimento Ingn Elettr, I-80125 Naples, Italy. [Greenhall, Charles] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Angrisani, L (reprint author), Univ Naples Federico II, Dipartimento Informat & Sistemist, Via Claudio 21, 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 NR 13 TC 1 Z9 1 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0957-0233 EI 1361-6501 J9 MEAS SCI TECHNOL JI Meas. Sci. Technol. PD OCT PY 2008 VL 19 IS 10 AR 105801 DI 10.1088/0957-0233/19/10/105801 PG 11 WC Engineering, Multidisciplinary; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 347BI UT WOS:000259113400027 ER PT J AU Kammer, DC Peck, JA AF Kammer, Daniel C. Peck, Jeffrey A. TI Mass-weighting methods for sensor placement using sensor set expansion techniques SO MECHANICAL SYSTEMS AND SIGNAL PROCESSING LA English DT Article DE sensor placement; modal testing; correlation ID LARGE SPACE STRUCTURES; MODAL IDENTIFICATION AB Placement of sensors is one of the most important tasks performed during pretest planning. The purpose of this work was to develop and investigate the use of an iterative Guyan expansion for mass weighting of target modes for sensor placement analogous to the common iterative Guyan reduction technique. The goal was to determine the appropriate mass-weighting approach to use in conjunction with effective independence sensor set expansion. In either sensor set expansion, or reduction, mass weighting requires a reduction of the FEM mass matrix to the current sensor set size Test-Analysis-Model (TAM). A general theory is presented for target mode mass weighting that can accommodate any type of reduction technique. The theory predicts that sensor set expansion using static mass weighting will result in sensor configurations that produce poor static TAMs. In contrast, sensor set expansion using modal mass weighting exactly reproduces the correct mass distribution during the expansion process. The results of a numerical example corroborate the theory. The modal mass sensor set expansion process produced significantly more accurate static TAMs than the static mass expansion. The modal expansion process was not quite as accurate as the iterative static reduction approach, but modal expansion was over 1600 times faster. (C) 2008 Elsevier Ltd. All rights reserved. C1 [Kammer, Daniel C.] Univ Wisconsin, Dept Engn Phys, Madison, WI 53706 USA. [Peck, Jeffrey A.] NASA, Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Kammer, DC (reprint author), Univ Wisconsin, Dept Engn Phys, 1500 Engn Dr, Madison, WI 53706 USA. EM Kammer@engr.wisc.edu NR 13 TC 10 Z9 10 U1 0 U2 4 PU ACADEMIC PRESS LTD ELSEVIER SCIENCE LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0888-3270 J9 MECH SYST SIGNAL PR JI Mech. Syst. Signal Proc. PD OCT PY 2008 VL 22 IS 7 BP 1515 EP 1525 DI 10.1016/j.ymssp.2008.01.002 PG 11 WC Engineering, Mechanical SC Engineering GA 329KN UT WOS:000257866600001 ER PT J AU Righter, K Yang, H Costin, G Downs, RT AF Righter, K. Yang, H. Costin, G. Downs, R. T. TI Oxygen fugacity in the Martian mantle controlled by carbon: New constraints from the nakhlite MIL 03346 SO METEORITICS & PLANETARY SCIENCE LA English DT Review ID COMPARATIVE PLANETARY MINERALOGY; CORE FORMATION; SNC METEORITES; MAGMA OCEAN; CLINOPYROXENE GEOBAROMETRY; EXPERIMENTAL PETROLOGY; BASALT PETROGENESIS; THERMODYNAMIC DATA; CUMULATE OVERTURN; ELEMENT CHEMISTRY AB Pyroxene structural data, along with analyses of titanomagnetite, fayalite and mesostasis of the new nakhlite Miller Range (MIL) 03346, define equilibration near 1 bar 1100 degrees C, and oxygen fugacity near the FMQ buffer. There is a clear progression of oxygen fugacity (fO(2)) in Martian meteorites from reduced Allan Hills (ALH) 84001 to intermediate shergottites to oxidized nakhlites. This trend can be explained by polybaric graphite-CO-CO2 equilibria in the Martian mantle. Shergottites would have formed at pressures between 1.2 and 3.0 GPa, and nakhlite parent liquids formed at pressures > 3.0 GPa, consistent with geochemical and petrologic data for the shergottites and nahklites. Carbon buffering in the Martian mantle Could be responsible for variation in fO(2) in Martian meteorites (rather than assimilation or crustal interaction), as well as C-H-O fluids that could be the source of similar to 30 ppb CH4 detected by recent spacecraft missions. The conundrum of an oxidized Current mantle and basalts. but reduced early mantle during core-mantle equilibrium exists for both the Earth and Mars. A polybaric buffering role for graphite can explain this discrepancy for Mars, and thus it may not be necessary to have all oxidation mechanism like the dissociation of MgFe-perovskite to account for the oxidized terrestrial mantle. C1 [Righter, K.] NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. [Yang, H.; Costin, G.; Downs, R. T.] Univ Arizona, Dept Geosci, Tucson, AZ 85721 USA. RP Righter, K (reprint author), NASA, Lyndon B Johnson Space Ctr, 2101 NASA Pkwy, Houston, TX 77058 USA. EM kevin.righter-1@nasa.gov FU NASA Cosmochemistry; Mars Fundamental Research RTOPs FX This research is funded by NASA Cosmochemistry and Mars Fundamental Research RTOPs, as well as a SURP for the systematic characterization of planetary surface materials awarded to the University of Arizona. NR 117 TC 44 Z9 44 U1 0 U2 12 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 1086-9379 EI 1945-5100 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD OCT PY 2008 VL 43 IS 10 BP 1709 EP 1723 PG 15 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 397KF UT WOS:000262660900008 ER PT J AU Mugnai, A Smith, EA Tripoli, GJ Dietrich, S Kotroni, V Lagouvardos, K Medaglia, CM AF Mugnai, A. Smith, E. A. Tripoli, G. J. Dietrich, S. Kotroni, V. Lagouvardos, K. Medaglia, C. M. TI Explaining discrepancies in passive microwave cloud-radiation databases in microphysical context from two different cloud-resolving models SO METEOROLOGY AND ATMOSPHERIC PHYSICS LA English DT Article ID PRECIPITATION RETRIEVAL; MESOSCALE MODEL; SCATTERING; ALGORITHM; RANGE; AIR AB Mesoscale Cloud Resolving Models (CRMs) are often used to generate descriptions of the microphysical properties of precipitating clouds for the purpose of guiding precipitation retrieval algorithms designed for satellite-borne passive microwave radiometers. However, CRMs were not originally designed for that purpose. Notably, individual CRMs have adopted different bulk microphysical schemes to optimize the dynamical evolution of storms and accumulated rainfall, rather than optimizing for simulations of radiative properties - which are greatly affected by the microphysical details and vertical distributions of liquid and frozen hydrometeors. Thus, in principle, the simulated upwelling passive microwave (PMW) brightness temperatures (T(B)s) and associated precipitation retrievals generated by means of different CRMs with different microphysical parameterizations may be significantly different - even when the different CRMs prognostically adhere to the main dynamical and precipitation characteristics of a given storm. We investigate this issue for two different mesoscale models run at CRM scales, each using different parameterizations for the ongoing microphysics. These are the University of Wisconsin Nonhydrostatic Modeling System (NMS) and the 5th generation version of the Pennsylvania State University/National Center for Atmospheric Research Mesoscale Model (MM5). These two models are used to simulate the same flood-producing storm that occurred over northern Italy during 24-26 November 2002. Model outputs that best reproduce the structure of the storm, as observed by the Advanced Microwave Scanning Radiometer (AMSR-E) onboard the NASA AQUA satellite, are used to calculate upwelling PMW T(B)s. The simulated T(B)s are then used for retrieving the precipitation fields in conjunction with the AMSR-E observations. Finally, the two sets of results are intercompared in order to provide an indication of the expected uncertainties in CRM-based precipitation retrievals due to differing microphysical parameterizations. Results show that the two models are in close agreement insofar as simulating the organizational characteristics of the storm, and that the bulk statistical properties of the two sets of retrieved precipitation rates are in close correspondence. By the same token, although the overall conditional bias is only 0.09, close examination of the two sets of retrievals indicates that rain rates begin to show their most significant differences above similar to 4.5mm h(-1), with differences larger than 10mm h(-1) occurring just under 2% of the time. C1 [Mugnai, A.; Dietrich, S.; Medaglia, C. M.] CNR, Inst Sci Atmosfera & Clima, I-00133 Rome, Italy. [Smith, E. A.] NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. [Tripoli, G. J.] Univ Wisconsin, Dept Atmospher & Ocean Sci, Madison, WI USA. [Kotroni, V.; Lagouvardos, K.] Natl Observ Athens, Inst Environm Res, Athens, Greece. RP Mugnai, A (reprint author), CNR, Inst Sci Atmosfera & Clima, Via Fosso Cavaliere 100, I-00133 Rome, Italy. EM a.mugnai@isac.cnr.it RI Kotroni, Vassiliki/D-5336-2014; Lagouvardos, Konstantinos/D-5683-2014; Dietrich, Stefano/C-3898-2015 OI Dietrich, Stefano/0000-0003-3808-365X FU European Commission FP6 - FLASH Project; European Community Initiative INTERREG III B CADSES - RISK AWARE project; Italian FISR-MIUR program "Sustainable Development and Climate Changes'' through the AEROCLOUDS project; Precipitation Measuring Missions (PMM) program of NASA; General Secretariat for Research and Technology FX This study has been supported by the European Commission FP6 - FLASH Project, by the European Community Initiative INTERREG III B CADSES - RISK AWARE project, by the Italian FISR-MIUR program "Sustainable Development and Climate Changes'' through the AEROCLOUDS project, by the Precipitation Measuring Missions (PMM) program of NASA, and by the Greek-Italian collaboration project financed by the General Secretariat for Research and Technology. NR 33 TC 9 Z9 9 U1 0 U2 3 PU SPRINGER WIEN PI WIEN PA SACHSENPLATZ 4-6, PO BOX 89, A-1201 WIEN, AUSTRIA SN 0177-7971 J9 METEOROL ATMOS PHYS JI Meteorol. Atmos. Phys. PD OCT PY 2008 VL 101 IS 3-4 BP 127 EP 145 DI 10.1007/s00703-007-0281-4 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 367HA UT WOS:000260541900003 ER PT J AU Mishchenko, MI Dlugach, JM AF Mishchenko, Michael I. Dlugach, Janna M. TI Weak localization of electromagnetic waves and radar polarimetry of Saturn's rings SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE polarization; radiative transfer; scattering; techniques : radar astronomy; planets : rings ID INVARIANT IMBEDDING METHOD; DISCRETE RANDOM-MEDIA; COHERENT BACKSCATTERING; POLARIZED-LIGHT; NONSPHERICAL PARTICLES; SPHERICAL-PARTICLES; MULTIPLE-SCATTERING; ENHANCEMENT FACTORS; RADIO OCCULTATION; CASSINI VIMS AB We use a state-of-the-art physics-based model of electromagnetic scattering to analyse average circular polarization ratios measured for the A and B rings of Saturn at a wavelength of 12.6 cm. This model is directly based on the Maxwell equations and accounts for the effects of polarization, multiple scattering, weak localization of electromagnetic waves and ring particle non- sphericity. Our analysis is based on the assumption that the observed polarization ratios are accurate, mutually consistent and show a quasi-linear dependence on the opening angle. Also, we assume that the ring system is not strongly stratified in the vertical direction. Our numerical simulations rule out the model of spherical ring particles, favour the model of ring bodies in the form of nearly spherical particles with small-scale surface roughness and rule out non-spherical particles with aspect ratios significantly exceeding 1.2. They also favour particles with effective radii in the range 4-10 cm and definitely rule out effective radii significantly smaller than 4 cm. Furthermore, they seem to rule out effective radii significantly > 10 cm. The retrieved ring optical thickness values are in the range 2-3 or even larger. If the rings do have a wake-like horizontal structure, as has been recently suggested, then these optical thickness values should be attributed to an average wake rather than to the optical thickness averaged over the entire horizontal extent of the rings. 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 Radiation Sciences Program FX We thank P. D. Nicholson for very useful comments which resulted in a much improved manuscript. This research was sponsored by the NASA Radiation Sciences Program managed by Hal Maring. NR 57 TC 6 Z9 6 U1 1 U2 3 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 1 PY 2008 VL 389 IS 4 BP 1665 EP 1674 DI 10.1111/j.1365-2966.2008.13725.x PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 349HJ UT WOS:000259271600014 ER PT J AU Rickenbach, T Kucera, P Gentry, M Carey, L Lare, A Lin, RF Demoz, B Starr, DO AF Rickenbach, Thomas Kucera, Paul Gentry, Megan Carey, Larry Lare, Andrew Lin, Ruei-Fong Demoz, Belay Starr, David O'C. TI The Relationship between Anvil Clouds and Convective Cells: A Case Study in South Florida during CRYSTAL-FACE SO MONTHLY WEATHER REVIEW LA English DT Article ID DIURNAL VARIABILITY; RADAR REFLECTIVITY; SQUALL LINE; LIFE-CYCLE; TOGA COARE; RAINFALL; TRMM; PRECIPITATION; MISSION; SYSTEM AB One of the important goals of NASA's Cirrus Regional Study of Tropical Anvils and Cirrus Layers Florida Area Cirrus Experiment (CRYSTAL-FACE) was to further the understanding of the evolution of tropical anvil clouds generated by deep convective systems. An important step toward understanding the radiative properties of convectively generated anvil clouds is to study their life cycle. Observations from ground-based radar, geostationary satellite radiometers, aircraft, and radiosondes during CRYSTAL-FACE provided a comprehensive look at the generation of anvil clouds by convective systems over South Florida during July 2002. This study focused on the relationship between convective rainfall and the evolution of the anvil cloud shield associated with convective systems over South Florida on 23 July 2002, during the CRYSTAL-FACE experiment. Anvil clouds emanating from convective cells grew downwind (to the southwest), reaching their maximum area at all temperature thresholds 1-2 h after the active convective cells collapsed. Radar reflectivity data revealed that precipitation-sized anvil particles extended downwind with the cloud tops. The time lag between maximum rainfall and maximum anvil cloud area increased with system size and rainfall. Observations from airborne radar and analysis of in situ cloud particle size distribution measurements in the anvil region suggested that gravitational size sorting of cloud particles dispersed downshear was a likely mechanism in the evolution of the anvil region. Linear regression analysis suggested a positive trend between this time lag and maximum convective rainfall for this case, as well as between the time lag and maximum system cloud cover. The injection of condensate into the anvil region by large areas of intense cells and dispersal in the upper-level winds was a likely explanation to cause the anvil cloud-top area to grow for 1-2 h after the surface convective rainfall began to weaken. In future work these relationships should be evaluated in differing regimes of shear, stability, or precipitation efficiency, such as over the tropical oceans, in order to generalize the results. The results of this study implied that for these cloud systems, the maximum in latent heating (proportional to rainfall) may precede the peak radiative forcing (related to anvil cloud height and area) by a lead time that was proportional to system size and strength. Mesoscale modeling simulations of convective systems on this day are under way to examine anvil evolution and growth mechanisms. C1 [Rickenbach, Thomas] E Carolina Univ, Dept Geog, Greenville, NC 27834 USA. [Kucera, Paul] Natl Ctr Atmospher Res, Res Applicat Lab, Boulder, CO 80307 USA. [Gentry, Megan] N Carolina State Univ, Dept Marine Earth & Atmospher Sci, Raleigh, NC 27695 USA. [Carey, Larry] Texas A&M Univ, Dept Atmospher Sci, College Stn, TX USA. [Lare, Andrew] Keane Fed Syst, Mclean, VA USA. [Lin, Ruei-Fong] Univ Maryland, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21201 USA. [Demoz, Belay; Starr, David O'C.] USN, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD USA. RP Rickenbach, T (reprint author), E Carolina Univ, Dept Geog, A-227 Brewster Bldg, Greenville, NC 27834 USA. EM rickenbacht@ecu.edu RI Y, wang/A-8866-2010; Demoz, Belay/N-4130-2014; OI Mallard, Megan/0000-0001-6548-8914 FU NASA Radiation Sciences program FX The authors gratefully acknowledge the support of the NASA Radiation Sciences program. The comments of two anonymous reviewers greatly improved the manuscript. NR 33 TC 15 Z9 16 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0027-0644 EI 1520-0493 J9 MON WEATHER REV JI Mon. Weather Rev. PD OCT PY 2008 VL 136 IS 10 BP 3917 EP 3932 DI 10.1175/2008MWR2441.1 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 361YO UT WOS:000260164200016 ER PT J AU Holland, DM Thomas, RH De Young, B Ribergaard, MH Lyberth, B AF Holland, David M. Thomas, Robert H. De Young, Brad Ribergaard, Mads H. Lyberth, Bjarne TI Acceleration of Jakobshavn Isbrae triggered by warm subsurface ocean waters SO NATURE GEOSCIENCE LA English DT Article ID GREENLAND ICE-SHEET; SUBPOLAR NORTH-ATLANTIC; THERMOHALINE CIRCULATION; WEST GREENLAND; GYRE AB Observations over the past decades show a rapid acceleration of several outlet glaciers in Greenland and Antarctica(1). One of the largest changes is a sudden switch of Jakobshavn Isbrae, a large outlet glacier feeding a deep-ocean fjord on Greenland's west coast, from slow thickening to rapid thinning(2) in 1997, associated with a doubling in glacier velocity(3). Suggested explanations for the speed-up of Jakobshavn Isbrae include increased lubrication of the ice-bedrock interface as more meltwater has drained to the glacier bed during recent warmer summers(4) and weakening and break-up of the floating ice tongue that buttressed the glacier(5). Here we present hydrographic data that show a sudden increase in subsurface ocean temperature in 1997 along the entire west coast of Greenland, suggesting that the changes in Jakobshavn Isbrae were instead triggered by the arrival of relatively warm water originating from the Irminger Sea near Iceland. We trace these oceanic changes back to changes in the atmospheric circulation in the North Atlantic region. We conclude that the prediction of future rapid dynamic responses of other outlet glaciers to climate change will require an improved understanding of the effect of changes in regional ocean and atmosphere circulation on the delivery of warm subsurface waters to the periphery of the ice sheets. C1 [Holland, David M.] NYU, New York, NY 10012 USA. [Thomas, Robert H.] Wallops Flight Facil, EG&G Serv, Wallops Isl, VA 23337 USA. [De Young, Brad] Mem Univ Newfoundland, St John, NF A1B 3X7, Canada. [Ribergaard, Mads H.] Danish Meteorol Inst, DK-2100 Copenhagen, Denmark. [Lyberth, Bjarne] Greenland Inst Nat Resources, Nuuk 3900, Greenland. RP Holland, DM (reprint author), NYU, 550 1St Ave, New York, NY 10012 USA. EM holland@cims.nyu.edu FU National Science Foundation [ARC-0644156] FX This research was primarily supported by a Strategic Grant for Exploratory Research from the Office of Polar Programs of the National Science Foundation (ARC-0644156). NR 30 TC 374 Z9 377 U1 12 U2 93 PU NATURE PUBLISHING GROUP PI NEW YORK PA 75 VARICK STREET, 9TH FLOOR, NEW YORK, NY 10013-1917 USA SN 1752-0894 J9 NAT GEOSCI JI Nat. Geosci. PD OCT PY 2008 VL 1 IS 10 BP 659 EP 664 DI 10.1038/ngeo316 PG 6 WC Geosciences, Multidisciplinary SC Geology GA 359RB UT WOS:000260004700011 ER PT J AU Binns, WR Wiedenbeck, ME Arnould, M Cummings, AC de Nolfe, GA Goriely, S Israel, MH Leske, RA Mewaldt, RA Stone, EC von Rosenvinge, TT AF Binns, W. R. Wiedenbeck, M. E. Arnould, M. Cummings, A. C. de Nolfe, G. A. Goriely, S. Israel, M. H. Leske, R. A. Mewaldt, R. A. Stone, E. C. von Rosenvinge, T. T. TI The OB association origin of galactic cosmic rays SO NEW ASTRONOMY REVIEWS LA English DT Article; Proceedings Paper CT 6th International Conference on Astronomy with Radioactivities CY JAN 07-10, 2008 CL Kreuth, GERMANY SP Max Planck Soc ID ISOTOPIC ANOMALIES; PARTICLE-ACCELERATION; SUPERBUBBLE ORIGIN; SUPERNOVA-REMNANTS; MASSIVE STARS; NUCLEOSYNTHESIS; ABUNDANCES; METALLICITY; EVOLUTION; GALAXY AB The isotopic abundances of neon, iron, and a number of other species in the galactic cosmic rays have been measured using the Cosmic Ray Isotope Spectrometer (CRIS) aboard the NASA Advanced Composition Explorer (ACE) spacecraft. We compare our data to results from two-component Wolf-Rayet (WR) models. The largest deviations of galactic cosmic ray (GCR) isotope ratios from solar-system ratios predicted by these models are C-12/O-16, Ne-22/Ne-20, and Fe-58/Fe-56. Our measured abundance ratios show good agreement with the model predictions. All of our measured isotopic ratios are consistent with a GCR source consisting of similar to 20% of WR material mixed with similar to 80% material with solar-system composition. Since WR stars are evolutionary products of OB stars, and most OB stars exist in OB associations, the good agreement of our data with these models strongly suggests that OB associations are the most probable source of at least a substantial fraction of GCRs. In previous work we have shown that the primary Ni-59 (which is radioactive and decays only by electron-capture) synthesized in supernovae has decayed prior to being accelerated to GCRs, indicating a time interval between nucleosynthesis and acceleration of >10(5) yr. In this paper we describe a scenario that should allow most of the Ni-59 to decay in the OB association environment and conclude that OB associations are the likely source of most GCRs. (C) 2008 Elsevier B.V. All rights reserved. C1 [Binns, W. R.; Israel, M. H.] Washington Univ, St Louis, MO 63130 USA. [Wiedenbeck, M. E.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Arnould, M.; Goriely, S.] ULB, Inst Astron & Astrophys, Brussels, Belgium. [Cummings, A. C.; Leske, R. A.; Mewaldt, R. A.; Stone, E. C.] CALTECH, Pasadena, CA 91125 USA. [de Nolfe, G. A.; von Rosenvinge, T. T.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Binns, WR (reprint author), Washington Univ, St Louis, MO 63130 USA. EM wrb@wuphys.wustl.edu NR 45 TC 24 Z9 24 U1 0 U2 1 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 1387-6473 J9 NEW ASTRON REV JI New Astron. Rev. PD OCT PY 2008 VL 52 IS 7-10 BP 427 EP 430 DI 10.1016/j.newar.2008.05.008 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 370BS UT WOS:000260738300018 ER PT J AU Weidenspointner, G Skinner, GK Jean, P Knodlseder, J von Ballmoos, P Diehl, R Strong, A Cordier, B Schanne, S Winkler, C AF Weidenspointner, G. Skinner, G. K. Jean, P. Knoedlseder, J. von Ballmoos, P. Diehl, R. Strong, A. Cordier, B. Schanne, S. Winkler, C. TI Positron astronomy with SPI/INTEGRAL SO NEW ASTRONOMY REVIEWS LA English DT Article; Proceedings Paper CT 6th International Conference on Astronomy with Radioactivities CY JAN 07-10, 2008 CL Kreuth, GERMANY SP Max Planck Soc DE Gamma-ray observations; Positron annihilation; Structure of Milky Way; Physical properties of ISM ID ANNIHILATION EMISSION; BLACK-HOLE; GAMMA-RAYS; MILKY-WAY; RADIATION; VIEW; SPI AB We provide an overview of positron astronomy results that have been obtained using the INTEGRAL spectrometer SPI, and discuss their implications for the still mysterious origin of positrons in our Galaxy. It has long been known that the 511 keV positron annihilation emission is strongest from the central region of our Galaxy. Recently, it has been discovered with the SPI spectrometer that the weaker 511 keV line emission from the inner Galactic disk appears to be asymmetric, with the emission to the west of the Galactic center being about twice as strong than that to the east. This distribution of positron annihilation resembles that of low mass X-ray binaries as observed with the INTEGRAL imager IBIS at hard X-ray energies, suggesting that these systems could provide a significant portion of the positrons in our Galaxy. In addition, the spectrometer SPI has permitted unprecedented spectroscopy of annihilation radiation from the bulge and disk regions of the Galaxy, which commences to yield important insights into the conditions of the medium in which the positrons annihilate. (C) 2008 Elsevier B.V. All rights reserved. C1 [Weidenspointner, G.; Diehl, R.; Strong, A.] Max Planck Inst Extraterr Phys, D-85741 Garching, Germany. [Weidenspointner, G.] MPI Halbleiterlab, D-81739 Munich, Germany. [Skinner, G. K.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Skinner, G. K.] CRESST, Greenbelt, MD 20771 USA. [Jean, P.; Knoedlseder, J.; von Ballmoos, P.] Ctr Etud Spatiale Rayonnements, F-31028 Toulouse 4, France. [Cordier, B.; Schanne, S.] CEA Saclay, DSM DAPNIA SAp, F-91191 Gif Sur Yvette, France. [Winkler, C.] ESA ESTEC, NL-2201 AZ Norrdwijk, Netherlands. RP Weidenspointner, G (reprint author), Max Planck Inst Extraterr Phys, Postfach 1312, D-85741 Garching, Germany. EM Georg.Weidenspointner@hll.mpg.de NR 21 TC 21 Z9 21 U1 0 U2 1 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 1387-6473 J9 NEW ASTRON REV JI New Astron. Rev. PD OCT PY 2008 VL 52 IS 7-10 BP 454 EP 456 DI 10.1016/j.newar.2008.06.019 PG 3 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 370BS UT WOS:000260738300024 ER PT J AU Kim, Z Zaretskey, V Yoon, Y Schneiderman, JF Shaw, MD Echternach, PM Wellstood, FC Palmer, BS AF Kim, Z. Zaretskey, V. Yoon, Y. Schneiderman, J. F. Shaw, M. D. Echternach, P. M. Wellstood, F. C. Palmer, B. S. TI Anomalous avoided level crossings in a Cooper-pair box spectrum SO PHYSICAL REVIEW B LA English DT Article ID SINGLE-ELECTRON TRANSISTORS; SMALL TUNNEL-JUNCTIONS; FLICKER 1/F NOISE; JOSEPHSON-JUNCTIONS; QUBIT AB We have observed a few distinct anomalous avoided level crossings and voltage-dependent transitions in the excited-state spectrum of an Al/AlOx/Al Cooper-pair box (CPB). The device was measured at 40 mK in the 15-50 GHz frequency range. We find that a given level crosses the CPB spectrum at two different gate voltages; the frequency and splitting size of the two crossings differ and the splitting size depends on the Josephson energy of the CPB. We show that this behavior is not only consistent with the CPB being coupled to discrete charged "two-level" quantum systems, which move atomic distances in the CPB junctions, but that the spectra provide information about the fluctuators, which is not available from phase qubit spectra of anomalous avoided levels. In particular by fitting a model Hamiltonian to our data, we extract microscopic parameters for each fluctuator, including well asymmetry, tunneling amplitude, and the minimum hopping distance for each fluctuator. The tunneling rates range from less than 3.5-13 GHz, which represent values between 5 and 150% of the well asymmetry, and the dipole moments give a minimum hopping distance of 0.3-0.8 A. We have also found that these discrete two-level systems have a pronounced effect on the relaxation time (T-1) of the quantum states of the CPB and hence can be a source of dissipation for superconducting quantum bits. C1 [Kim, Z.; Zaretskey, V.; Palmer, B. S.] Lab Phys Sci, College Pk, MD 20740 USA. [Kim, Z.; Zaretskey, V.; Yoon, Y.; Wellstood, F. C.] Univ Maryland, Dept Phys, College Pk, MD 20742 USA. [Shaw, M. D.] Univ So Calif, Dept Phys, Los Angeles, CA 90089 USA. [Echternach, P. M.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Wellstood, F. C.] Joint Quantum Inst, College Pk, MD 20742 USA. [Wellstood, F. C.] Ctr Nanophys & Adv Mat, College Pk, MD 20742 USA. RP Kim, Z (reprint author), Lab Phys Sci, College Pk, MD 20740 USA. EM bpalmer@lps.umd.edu RI Joint Quantum Institute, NIST/UMD/H-4494-2011; Schneiderman, Justin/D-4508-2013 OI Schneiderman, Justin/0000-0002-4441-2360 FU National Security Agency; Joint Quantum Institute; State of Maryland through the Center for Nanophysics and Advanced Materials FX This research was supported by the National Security Agency. The authors would like to thank E. Tiesinga, R. Simmonds, and K. Osborn for many useful discussions of microstates. F. C. W. would like to acknowledge support from the Joint Quantum Institute and the State of Maryland through the Center for Nanophysics and Advanced Materials. NR 37 TC 36 Z9 36 U1 0 U2 4 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD OCT PY 2008 VL 78 IS 14 AR 144506 DI 10.1103/PhysRevB.78.144506 PG 6 WC Physics, Condensed Matter SC Physics GA 367TA UT WOS:000260574300076 ER PT J AU Sutton, A Shaddock, DA AF Sutton, Andrew Shaddock, Daniel A. TI Laser frequency stabilization by dual arm locking for LISA SO PHYSICAL REVIEW D LA English DT Article AB The Laser Interferometer Space Antenna (LISA) will be the first dedicated space based gravitational wave detector. LISA will consist of a triangular formation of spacecraft, forming an interferometer with 5 x 10(6) km long arms. Annual length variations of the interferometer arms prevent exact laser frequency noise cancellation. Despite prestabilization to an optical cavity the expected frequency noise is many orders of magnitude larger than the required levels. Arm locking is a feedback control method that will further stabilize the laser frequency by referencing it to the 5 x 10(6) km arms. Although the original arm locking scheme produced a substantial noise reduction, the technique suffered from slowly decaying start-up transients and excess noise at harmonic frequencies of the inverse round-trip time. Dual arm locking, presented here, improves on the original scheme by combining information from two interferometer arms for feedback control. Compared to conventional arm locking, dual arm locking exhibits significantly reduced start-up transients, no noise amplification at frequencies within the LISA signal band, and more than 50 fold improvement in noise suppression at low frequencies. In this article we present a detailed analysis of the dual arm locking control system and present simulation results showing a noise reduction of 10 000 at a frequency of 10 mHz. C1 [Sutton, Andrew; Shaddock, Daniel A.] Australian Natl Univ, Ctr Gravitat Phys, Canberra, ACT 0200, Australia. [Shaddock, Daniel A.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Sutton, A (reprint author), Australian Natl Univ, Ctr Gravitat Phys, GPO Box 4, Canberra, ACT 0200, Australia. EM Andrew.Sutton@ieee.org; Daniel.Shaddock@jpl.nasa.gov RI Shaddock, Daniel/A-7534-2011 OI Shaddock, Daniel/0000-0002-6885-3494 FU National Aeronautics and Space Administration (NASA) FX We thank Hans-Reiner Schulte, Peter Gath, Guido Mueller, and Malcolm Gray for many useful discussions. Part of this research was performed at the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration (NASA). NR 11 TC 11 Z9 12 U1 0 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 OCT PY 2008 VL 78 IS 8 AR 082001 DI 10.1103/PhysRevD.78.082001 PG 7 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 367TG UT WOS:000260574900006 ER PT J AU Vanderveld, RA Flanagan, EE Wasserman, I AF Vanderveld, R. Ali Flanagan, Eanna E. Wasserman, Ira TI Luminosity distance in "Swiss cheese" cosmology with randomized voids. I. Single void size SO PHYSICAL REVIEW D LA English DT Article ID SUPERNOVAE; UNIVERSE; QUINTESSENCE AB Recently, there have been suggestions that the Type Ia supernova data can be explained using only general relativity and cold dark matter with no dark energy. In "Swiss cheese" models of the Universe, the standard Friedmann-Robertson-Walker picture is modified by the introduction of mass-compensating spherical inhomogeneities, typically described by the Lemaitre-Tolman-Bondi metric. If these inhomogeneities correspond to underdense cores surrounded by mass-compensating overdense shells, then they can modify the luminosity distance-redshift relation in a way that can mimic accelerated expansion. It has been argued that this effect could be large enough to explain the supernova data without introducing dark energy or modified gravity. We show that the large apparent acceleration seen in some models can be explained in terms of standard weak field gravitational lensing together with insufficient randomization of void locations. The underdense regions focus the light less than the homogeneous background, thus dimming supernovae in a way that can mimic the effects of acceleration. With insufficient randomization of the spatial location of the voids and of the lines of sight, coherent defocusing can lead to anomalously large demagnification effects. We show that a proper randomization of the voids and lines of sight reduces the effect to the point that it can no longer explain the supernova data. C1 [Vanderveld, R. Ali] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Flanagan, Eanna E.; Wasserman, Ira] Cornell Univ, Ctr Radiophys & Space Res, Ithaca, NY 14853 USA. [Flanagan, Eanna E.; Wasserman, Ira] Cornell Univ, Lab Elementary Particle Phys, Ithaca, NY 14853 USA. RP Vanderveld, RA (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. FU NSF [PHY-0457200, PHY-0555216]; NASA [NNX08AH27G] FX The work of R. A. V. was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with NASA. We also acknowledge the support of NSF Grant Nos. PHY-0457200 and PHY-0555216, and NASA Grant No. NNX08AH27G. NR 34 TC 52 Z9 52 U1 0 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 OCT PY 2008 VL 78 IS 8 AR 083511 DI 10.1103/PhysRevD.78.083511 PG 6 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 367TG UT WOS:000260574900032 ER PT J AU Okong'o, N Leboissetier, A Bellan, J AF Okong'o, Nora Leboissetier, Anthony Bellan, Josette TI Detailed characteristics of drop-laden mixing layers: Large eddy simulation predictions compared to direct numerical simulation SO PHYSICS OF FLUIDS LA English DT Article ID MACH-NUMBER TURBULENCE; EVAPORATING DROPLETS; PARTICLE DISPERSION; SPRAY COMBUSTION; SUBGRID ANALYSIS; SCALE MODELS; FLOWS; CHANNEL AB Results are compared from direct numerical simulation (DNS) and large eddy simulation (LES) of a temporal mixing layer laden with evaporating drops to assess the ability of LES to reproduce detailed characteristics of DNS. The LES used computational drops, each of which represented eight physical drops, and a reduced flow field resolution using a grid spacing four times larger than that of the DNS. The LES also used models for the filtered source terms, which express the coupling of the drops with the flow, and for the unresolved subgrid-scale (SGS) fluxes of species mass, momentum, and enthalpy. The LESs were conducted using one of three different SGS-flux models: dynamic-coefficient gradient (GRD), dynamic-coefficient Smagorinsky (SMD), and constant-coefficient scale similarity (SSC). The comparison of the LES with the filtered-and-coarsened (FC) DNS considered detailed aspects of the flow that are of interest in ignition or full combustion. All LESs captured the largest-scale vortex, the global amount of vapor emanating from the drops, and the overall size distribution of the drops. All LESs tended to underpredict the global amount of irreversible entropy production (dissipation). The SMD model was found unable to capture either the global or local vorticity variation and had minimal small-scale activity in dynamic and thermodynamic variables compared to the FC-DNS. The SMD model was also deficient in predicting the spatial distribution of drops and of the dissipation. In contrast, the GRD and SSC models did mimic the small-scale activity of the FC-DNS and the spatial distribution of drops and of the dissipation. Therefore, the GRD and SSC models are recommended, while the SMD model seems inappropriate for combustion or other problems where the local activity must be predicted. (C) 2008 American Institute of Physics. [DOI: 10.1063/1.2990758] C1 [Okong'o, Nora; Leboissetier, Anthony; Bellan, Josette] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Bellan, J (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM josette.bellan@jpl.nasa.gov FU Jet Propulsion Laboratory (JPL) of the California Institute of Technology (Caltech) under the sponsorship of the U. S. Department of Energy FX This study was conducted at the Jet Propulsion Laboratory (JPL) of the California Institute of Technology (Caltech) under the sponsorship of the U. S. Department of Energy, with R. Danz and D. Hooker serving as contract monitors, under an agreement with the National Aeronautics and Space Administration. Computations were performed on the SGI Origin 2000 at the JPL Supercomputing Center. NR 39 TC 8 Z9 8 U1 1 U2 7 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 1070-6631 J9 PHYS FLUIDS JI Phys. Fluids PD OCT PY 2008 VL 20 IS 10 AR 103305 DI 10.1063/1.2990758 PG 16 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA 367SM UT WOS:000260572800032 ER PT J AU Wallace, JM Ong, L AF Wallace, James M. Ong, Lawrence TI Local isotropy of the velocity and vorticity fields in a boundary layer at high Reynolds numbers SO PHYSICS OF FLUIDS LA English DT Article; Proceedings Paper CT Workshop on Turbulence Physics and Control CY SEP 14-15, 2007 CL Stanford Univ, Stanford, CA HO Stanford Univ ID TURBULENT WAKE; DISSIPATION; SPECTRA; SCALES; FLUID AB Measurements of the velocity and vorticity field with a 12-sensor hot-wire probe were carried out in the boundary layer of the test section ceiling of the NASA Ames 80 x 120 ft(2) wind tunnel at a turbulence Reynolds number of R(lambda) approximate to 875. Tests of local isotropy were applied to the data obtained at y/delta=0.1. In the inertial subrange, which extended over a decade of wave numbers for this experiment, both the velocity and vorticity component one-dimensional k(x) spectra agree well with the isotropic spectra of Kim and Antonia [J. Fluid Mech. 251, 219 (1993)]. This agreement extends into the dissipation range up to wave numbers at which the accuracy of the measurements is limited because of spatial resolution and other sources of error. Additional tests of local isotropy, from the characteristics of the Reynolds shear stress correlation coefficient cospectrum and from the isotropic relationships between the k(x) spectra of the streamwise velocity and vorticity components with the k(x) spectra of the respective cross-stream components, also show evidence of local isotropy at these higher wave numbers. c 2008 American Institute of Physics. [DOI: 10.1063/1.3005842] C1 [Wallace, James M.] Univ Maryland, Dept Mech Engn, Burgers Program Fluid Dynam, College Pk, MD 20742 USA. [Ong, Lawrence] NASA, Goddard Space Flight Ctr, Sci Syst & Applicat Inc, Greenbelt, MD 20771 USA. RP Wallace, JM (reprint author), Univ Maryland, Dept Mech Engn, Burgers Program Fluid Dynam, College Pk, MD 20742 USA. NR 14 TC 3 Z9 3 U1 0 U2 3 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 1070-6631 J9 PHYS FLUIDS JI Phys. Fluids PD OCT PY 2008 VL 20 IS 10 AR 101506 DI 10.1063/1.3005842 PG 7 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA 367SM UT WOS:000260572800006 ER PT J AU Zhu, X Strobel, DF Flasar, MF AF Zhu, Xun Strobel, Darrell F. Flasar, Michael F. TI Exchange of global mean angular momentum between an atmosphere and its underlying planet SO PLANETARY AND SPACE SCIENCE LA English DT Article DE Atmospheric boundary layer; Atmospheric dynamics; Meteorology ID EQUATORIAL SUPERROTATION; TITAN; MAINTENANCE AB This paper investigates the exchange of global mean angular momentum between an atmosphere and its underlying planet by a simple model. The model parameterizes four processes that are responsible for zonal mean momentum budget in the atmospheric boundary layer for a rotating planet: (i) meridional circulation that redistributes the relative angular momentum, (ii) horizontal diffusion that smoothes the prograde and retrograde winds, (iii) frictional drag that exchanges atmospheric angular momentum with the underlying planet, and (iv) internal redistribution of the zonal mean momentum by wave drag. It is shown that under a steady-state or a long-term average condition, the global relative angular momentum in the boundary layer vanishes unless there exists a preferred frictional drag for either the prograde or the retrograde zonal wind. We further show quantitatively that one cannot have either a predominant steady prograde or retrograde wind in the boundary layer of a planetary atmosphere. The parameter dependencies of the global relative angular momentum and the strength of the atmospheric circulation in the boundary layer are derived explicitly and used to explain the observational differences between the atmospheres of Earth and Venus. (C) 2008 Elsevier Ltd. All rights reserved. C1 [Zhu, Xun] Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. [Strobel, Darrell F.] Johns Hopkins Univ, Dept Earth & Planetary Sci, Baltimore, MD 21218 USA. [Strobel, Darrell F.] Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. [Flasar, Michael F.] NASA, Goddard Space Flight Ctr, Planetary Syst Branch, Greenbelt, MD 20771 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; strobel@jhu.edu; F.M.Flasar@gsfc.nasa.gov RI Zhu, Xun/C-2097-2016 OI Zhu, Xun/0000-0001-7860-6430 FU NSF [ATM-0730158]; NASA [NAG5-11962, NAG5-12051]; Johns Hopkins University Applied Physics Laboratory and School of Arts and Sciences FX The authors appreciate the helpful comments by the two anonymous reviewers. This research was supported by NSF Grant ATM-0730158 and in part by NASA Grants NAG5-11962 and NAG5-12051 to The Johns Hopkins University Applied Physics Laboratory and School of Arts and Sciences. NR 17 TC 4 Z9 4 U1 0 U2 0 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 OCT PY 2008 VL 56 IS 11 BP 1524 EP 1531 DI 10.1016/j.pss.2008.05.014 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 373NW UT WOS:000260979700010 ER PT J AU Zhang, H AF Zhang, Hui TI Structure and dynamics of high latitude magnetospheric boundaries SO PLANETARY AND SPACE SCIENCE LA English DT Article C1 [Zhang, Hui] Boston Univ, Ctr Space Phys, Boston, MA 02215 USA. RP Zhang, H (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. EM zhang@bu.edu NR 4 TC 0 Z9 0 U1 1 U2 1 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 OCT PY 2008 VL 56 IS 11 BP 1568 EP 1570 DI 10.1016/j.pss.2008.08.014 PG 3 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 373NW UT WOS:000260979700017 ER PT J AU Saha, S Puthenpurayil, S Schlessman, J Bhattacharyya, SS Wolf, W AF Saha, Sankalita Puthenpurayil, Sebastian Schlessman, Jason Bhattacharyya, Shuvra S. Wolf, Wayne TI The Signal Passing Interface and Its Application to Embedded Implementation of Smart Camera Applications SO PROCEEDINGS OF THE IEEE LA English DT Article DE Dataflow; face detection; multiprocessor communication; smart camera; speech compression AB Embedded smart camera systems comprise computation- and resource-hungry applications implemented on small, complex but resource-hardy platforms. Efficient implementation of such applications can benefit significantly from parallelization. However, communication between different processing units is a nontrivial task. in addition, new and emerging distributed smart cameras require efficient methods of communication for optimized distributed implementations. in this paper, a novel communication interface, called the signal passing interface (SPI), is presented that attempts to overcome this challenge by integrating relevant properties of two different, yet important, paradigms in this context-dataflow and message passing interface (MPI). Dataflow is a widely used modeling paradigm for signal processing applications, while MPI is an established communication interface in the general-purpose processor community. SPI is targeted toward computation-intensive signal processing applications, and due to its careful specialization, more performance-efficient for embedded implementation in this domain. SPI is also much easier and more intuitive to use. In this paper, Successful application of this communication interface to two smart camera applications has been presented in detail to validate a new methodology for efficient distributed implementation for this domain. C1 [Saha, Sankalita] NASA, Ames Res Ctr, Res Inst Adv Comp Studies, Mountain View, CA 94040 USA. [Puthenpurayil, Sebastian; Bhattacharyya, Shuvra S.] Univ Maryland, Dept Elect & Comp Engn, College Pk, MD 20742 USA. [Puthenpurayil, Sebastian; Bhattacharyya, Shuvra S.] Univ Maryland, Inst Adv Comp Studies, College Pk, MD 20742 USA. [Schlessman, Jason] Princeton Univ, Dept Elect Engn, Princeton, NJ 08544 USA. [Wolf, Wayne] Georgia Inst Technol, Dept Elect & Comp Engn, Atlanta, GA 30332 USA. RP Saha, S (reprint author), NASA, Ames Res Ctr, Res Inst Adv Comp Studies, Mountain View, CA 94040 USA. EM ssaha@riacs.edu; purayil@umd.edu; jschless@princeton.edu; ssb@umd.edu; wolf@ece.gatech.edu OI Bhattacharyya, Shuvra/0000-0001-7719-1106 FU National Science Foundation [0325119] FX This work was support in part by the National Science Foundation under Grant 0325119. NR 32 TC 1 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 0018-9219 EI 1558-2256 J9 P IEEE JI Proc. IEEE PD OCT PY 2008 VL 96 IS 10 SI SI BP 1576 EP 1587 DI 10.1109/JPROC.2008.928744 PG 12 WC Engineering, Electrical & Electronic SC Engineering GA 372JZ UT WOS:000260899200004 ER PT J AU Lachter, J Ruthruff, E Lien, MC McCann, RS AF Lachter, Joel Ruthruff, Eric Lien, Mei-Ching McCann, Robert S. TI Is attention needed for word identification? Evidence from the Stroop paradigm SO PSYCHONOMIC BULLETIN & REVIEW LA English DT Article ID SELECTION; TASKS AB One of the most robust findings in attention research is that the time to name a color is lengthened markedly in the presence of an irrelevant word that spells a different color name: the Stroop effect. The Stroop effect is found even when the word is physically separated from the color, apparently indicating that words can be read outside the focus of spatial attention. The present study critically evaluated this claim. We employed several stringent measures within a Stroop paradigm to prevent participants from attending to the irrelevant words (e.g., limiting exposure duration to prevent attention capture). Nonetheless, residual Stroop effects were obtained for both color words and semantic associates (e.g., sky to blue). These data suggest that lexical processing can sometimes occur outside the focus of spatial attention. C1 [Lachter, Joel; McCann, Robert S.] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. [Lachter, Joel] San Jose State Univ, San Jose, CA 95192 USA. [Ruthruff, Eric] Univ New Mexico, Albuquerque, NM 87131 USA. [Lien, Mei-Ching] Oregon State Univ, Corvallis, OR 97331 USA. RP Lachter, J (reprint author), NASA, Ames Res Ctr, Mail Stop 262-4, Moffett Field, CA 94035 USA. EM joel.b.lachter@nasa.gov NR 15 TC 17 Z9 17 U1 3 U2 11 PU PSYCHONOMIC SOC INC PI AUSTIN PA 1710 FORTVIEW RD, AUSTIN, TX 78704 USA SN 1069-9384 J9 PSYCHON B REV JI Psychon. Bull. Rev. PD OCT PY 2008 VL 15 IS 5 BP 950 EP 955 DI 10.3758/PBR.15.5.950 PG 6 WC Psychology, Mathematical; Psychology, Experimental SC Psychology GA 372VJ UT WOS:000260929800008 PM 18926987 ER PT J AU Gladysz, S Christou, JC Bradford, LW Roberts, LC AF Gladysz, Szymon Christou, Julian C. Bradford, L. William Roberts, Lewis C., Jr. TI Temporal Variability and Statistics of the Strehl Ratio in Adaptive-Optics Images SO PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF THE PACIFIC LA English DT Article AB We have investigated the temporal variability and statistics of the "instantaneous" Strehl ratio. The observations were carried out with the 3.63-m AEOS telescope equipped with a high-order adaptive-optics system. In this paper Strehl ratio is defined as the peak intensity of a single short exposure. We have also studied the behavior of the phase variance computed on the reconstructed wavefronts. We tested the Marechal approximation and used it to explain the observed negative skewness of the Strehl ratio distribution. The estimate of the phase variance is shown to fit a three-parameter Gamma distribution model. We show that simple scaling of the reconstructed wavefronts has a large impact on the shape of the Strehl ratio distribution. C1 [Gladysz, Szymon] Natl Univ Ireland, Dept Expt Phys, Galway, Ireland. [Christou, Julian C.] Natl Sci Fdn, Div Astron Sci, Arlington, VA 22230 USA. [Bradford, L. William] Pacific Def Solut, Kihei, HI USA. [Roberts, Lewis C., Jr.] CALTECH, Jet Prop Lab, Pasadena, CA USA. RP Gladysz, S (reprint author), Natl Univ Ireland, Dept Expt Phys, Galway, Ireland. EM szymon.gladysz@nuigalway.ie; jchristo@nsf.gov; bill.bradford@pacificds.com; lewis.c.roberts@jpl.nasa.gov OI Roberts, Lewis/0000-0003-3892-2900 FU Science Foundation Ireland [02/PI.2/039C, 07/IN.1/I906]; National Science Foundation Science and Technology Center for Adaptive Optics; University of California at Santa Cruz [AST 98-76783]; Air Force Office of Scientific Research; Air Force Research Laboratory's Directed Energy Directorate [F29601-00-D0204, FA9451-05-C-0257] FX This research was supported by Science Foundation Ireland under Grants 02/PI.2/039C and 07/IN.1/I906, as well as the National Science Foundation Science and Technology Center for Adaptive Optics, which is managed by the University of California at Santa Cruz under cooperative agreement AST 98-76783. Our work was also funded by the Air Force Office of Scientific Research and by Air Force Research Laboratory's Directed Energy Directorate under contracts F29601-00-D0204 and FA9451-05-C-0257. We would like to thank Granville Tunnicliffe-Wilson and Jerome Sheahan for the introduction to time series analysis and Chris Dainty for support for this research. The authors wish to acknowledge the SFI/HEA Irish Centre for High-End Computing (ICHEC) for the provision of computational facilities and support. NR 27 TC 16 Z9 16 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 OCT PY 2008 VL 120 IS 872 BP 1132 EP 1143 DI 10.1086/592787 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 364FH UT WOS:000260321100007 ER PT J AU Ehrendorfer, M Errico, RA AF Ehrendorfer, Martin Errico, Ronald A. TI An atmospheric model of intermediate complexity for data assimilation studies SO QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY LA English DT Article DE Intermediate-complexity model; data assimilation; singular vectors; predictability; geostrophy ID NUMERICAL WEATHER PREDICTION; OPTIMAL UNSTABLE STRUCTURES; SINGULAR-VECTOR STRUCTURE; KALMAN FILTER; TOTAL-ENERGY; PREDICTABILITY; CIRCULATION; SIMULATION; RESOLUTION; TRANSIENT AB Atmospheric models of intermediate complexity play an important role when studying atmospheric phenomena. Their complexity is between highly truncated low-dimensional 'toy' models and modern general Circulation or numerical weather prediction models. By design, computational cost associated with intermediate models is much reduced while at the same time some important aspects of atmospheric behaviour arc still reasonably realistically described. Performing numerical experimentation with such models in the contexts of data assimilation, predictability, and atmospheric dynamics can produce informative results regarding those aspects for comparatively low cost. Nevertheless, as with any model-based study, the degree to which results so obtained may be generalized to more realistic conditions remains somewhat uncertain and dependent on the specific questions being considered. An intermediate-complexity model, named AMIC (Atmospheric Model of Intermediate Complexity) based on the nonlinear quasi-geostrophic potential vorticity equation is presented. This global model uses a spectral dynamical core, and contains 'physical processes', Such as climatological forcing, diffusion, and damping, designed to reasonably match AMIC's behaviour with observed atmospheric properties. While AMIC has variable horizontal and vertical resolution, the properties of AMIC are studied here for two specific resolutions (T45L6 and T1061-9) and these are compared against atmospheric properties in terms of energy spectra, time-mean and transient behaviour, and singular-vector perturbation growth. The model's behaviour is reasonably realistic, except for its transient activity being somewhat weak, especially in the Southern (summer) hemisphere. AMIC is also suited for some data assimilation and predictability studies since it contains complete tangent-linear and adjoint models. Copyright (C) 2008 Royal Meteorological Society C1 [Errico, Ronald A.] NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Greenbelt, MD 20771 USA. [Errico, Ronald A.] Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21228 USA. RP Errico, RA (reprint author), NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Code 660-1, Greenbelt, MD 20771 USA. EM ronald.m.errico@nasa.gov NR 74 TC 3 Z9 3 U1 0 U2 3 PU JOHN WILEY & SONS LTD PI CHICHESTER PA THE ATRIUM, SOUTHERN GATE, CHICHESTER PO19 8SQ, W SUSSEX, ENGLAND SN 0035-9009 J9 Q J ROY METEOR SOC JI Q. J. R. Meteorol. Soc. PD OCT PY 2008 VL 134 IS 636 BP 1717 EP 1732 DI 10.1002/qj.329 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 404PS UT WOS:000263166100006 ER PT J AU Norris, PM Oreopoulos, L Hou, AY Tao, WK Zeng, XP AF Norris, Peter M. Oreopoulos, Lazaros Hou, Arthur Y. Tao, Wei-Kuo Zeng, Xiping TI Representation of 3D heterogeneous cloud fields using copulas: Theory for water clouds SO QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY LA English DT Article DE statistical cloud parametrizations; cloud overlap; cloud heterogeneity; radiative transfer; rank statistics ID MAXIMUM-LIKELIHOOD-ESTIMATION; MULTIVARIATE-T-PROBABILITIES; ERROR COVARIANCE PARAMETERS; LARGE-SCALE MODELS; PART I; NUMERICAL COMPUTATION; GENERAL-CIRCULATION; OVERLAP STATISTICS; RESOLVING MODEL; LAYER CLOUDS AB It is shown that a general representation of GCM column cloud fraction within probability density function (PDF)-based statistical cloud parametrizations can be obtained using statistical functions called copulas that encapsulate the dependence structure of rank statistics in a multivariate system. Using this theory, a new Gaussian copula formulation of GCM cloud overlap is obtained. The copula approach provides complete flexibility in the choice of the marginal PDF of each layer's moisture and temperature, and, compared with earlier approaches, including the 'generalized overlap' approach, allows a far more general specification of the correlation between any pair of layers. It also allows easy addition of new layer variables, such as temperature, into the modelled grid-column statistics. As a preliminary test of this formulation, its ability to statistically describe a cloud-resolving model simulation of a complex multi-layer case-study, including both large-scale and convective clouds, is examined. The Gaussian copula cloud fraction is found to be significantly less biased than other common cloud overlap methods for this case-study. Estimates of several nonlinear quantities are also improved with the Gaussian copula model: the variance of condensed water path and the fluxes of solar and thermal radiation at atmospheric column boundaries. This first paper, though limited to the simpler case of water clouds, addresses subgrid-scale variability in both moisture and temperature. This work is envisaged as a first step towards developing a generalized statistical framework for GCM cloud parametrization and for assimilating statistical information from high-resolution satellite observations into GCMs and global analyses. Copyright (C) 2008 Royal Meteorological Society C1 [Norris, Peter M.; Hou, Arthur Y.] NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Greenbelt, MD 20771 USA. [Norris, Peter M.; Zeng, Xiping] Univ Maryland, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21201 USA. [Oreopoulos, Lazaros] Univ Maryland, Joint Ctr Earth Syst Technol, Baltimore, MD 21201 USA. [Oreopoulos, Lazaros; Tao, Wei-Kuo; Zeng, Xiping] NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. RP Norris, PM (reprint author), NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Code 660-1, Greenbelt, MD 20771 USA. EM peter.m.norris@nasa.gov RI Hou, Arthur/D-8578-2012; Oreopoulos, Lazaros/E-5868-2012; Norris, Peter/H-2008-2012 OI Oreopoulos, Lazaros/0000-0001-6061-6905; Norris, Peter/0000-0001-6807-9884 NR 40 TC 18 Z9 18 U1 0 U2 2 PU JOHN WILEY & SONS LTD PI CHICHESTER PA THE ATRIUM, SOUTHERN GATE, CHICHESTER PO19 8SQ, W SUSSEX, ENGLAND SN 0035-9009 J9 Q J ROY METEOR SOC JI Q. J. R. Meteorol. Soc. PD OCT PY 2008 VL 134 IS 636 BP 1843 EP 1864 DI 10.1002/qj.321 PG 22 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 404PS UT WOS:000263166100015 ER PT J AU Brown, GV Beiersdorfer, P Emig, J Frankel, M Gu, MF Heeter, RF Magee, E Thorn, DB Widmann, K Kelley, RL Kilbourne, CA Porter, FS AF Brown, G. V. Beiersdorfer, P. Emig, J. Frankel, M. Gu, M. F. Heeter, R. F. Magee, E. Thorn, D. B. Widmann, K. Kelley, R. L. Kilbourne, C. A. Porter, F. S. TI Rapid, absolute calibration of x-ray filters employed by laser-produced plasma diagnostics SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article; Proceedings Paper CT 17th Topical Conference on High-Temperature Plasma Diagnostics CY 2008 CL Albuquerque, NM DE calibration; plasma diagnostics; X-ray detection ID BEAM ION-TRAP; SPECTROMETER; REGION; XRS AB The Electron Beam Ion Trap (EBIT) facility at the Lawrence Livermore National Laboratory is being used to absolutely calibrate the transmission efficiency of x-ray filters employed by diodes and spectrometers used to diagnose laser-produced plasmas. EBIT emits strong, discrete monoenergetic lines at appropriately chosen x-ray energies. X rays are detected using the high resolution EBIT Calorimeter Spectrometer (ECS), developed for LLNL at the NASA/Goddard Space Flight Center. X-ray filter transmission efficiency is determined by dividing the x-ray counts detected when the filter is in the line of sight by those detected when out of the line of sight. Verification of filter thickness can be completed in only a few hours, and absolute efficiencies can be calibrated in a single day over a broad range from about 0.1 to 15 keV. The EBIT calibration lab has been used to field diagnostics (e.g., the OZSPEC instrument) with fully calibrated x-ray filters at the OMEGA laser. Extensions to use the capability for calibrating filter transmission for the DANTE instrument on the National Ignition Facility are discussed. C1 [Brown, G. V.; Beiersdorfer, P.; Emig, J.; Frankel, M.; Gu, M. F.; Heeter, R. F.; Magee, E.; Thorn, D. B.; Widmann, K.] Lawrence Livermore Natl Lab, Dept Phys Sci, High Energy Dens Phys & Astrophys Div, Livermore, CA 94550 USA. [Kelley, R. L.; Kilbourne, C. A.; Porter, F. S.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20770 USA. RP Brown, GV (reprint author), Lawrence Livermore Natl Lab, Dept Phys Sci, High Energy Dens Phys & Astrophys Div, 7000 East Ave,L 260, Livermore, CA 94550 USA. RI Porter, Frederick/D-3501-2012; Kelley, Richard/K-4474-2012 OI Porter, Frederick/0000-0002-6374-1119; NR 12 TC 3 Z9 3 U1 0 U2 3 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 OCT PY 2008 VL 79 IS 10 AR 10E309 DI 10.1063/1.2965214 PG 3 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 367ST UT WOS:000260573500067 PM 19044471 ER PT J AU Porter, FS Gygax, J Kelley, RL Kilbourne, CA King, JM Beiersdorfer, P Brown, GV Thorn, DB Kahn, SM AF Porter, Frederick Scott Gygax, John Kelley, Richard L. Kilbourne, Caroline A. King, Jonathan M. Beiersdorfer, Peter Brown, Gregory V. Thorn, Daniel B. Kahn, Steven M. TI Performance of the EBIT calorimeter spectrometer SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article; Proceedings Paper CT 17th Topical Conference on High-Temperature Plasma Diagnostics CY 2008 CL Albuquerque, NM DE cryogenics; electron beams; X-ray spectrometers ID XRS AB The EBIT calorimeter spectrometer (ECS) is a new high-resolution, broadband x-ray spectrometer that has recently been installed at the Electron Beam Ion Trap Facility (EBIT) at the Lawrence Livermore National Laboratory. The ECS is an entirely new production class spectrometer that replaces the XRS/EBIT spectrometer that has been operating at EBIT since 2000. The ECS utilizes a 32-pixel x-ray calorimeter array from the XRS instrument on the Suzaku x-ray observatory. Eighteen of the pixels are optimized for the 0.1-10 keV band and yield 4.5 eV full width at half maximum energy resolution and 95% quantum efficiency at 6 keV. In addition, the ECS includes 14 detector pixels that are optimized for the high-energy band with a bandpass from 0.5 to over 100 keV with 34 eV resolution and 32% quantum efficiency at 60 keV. The ECS detector array is operated at 50 mK using a five stage cryogenic system that is entirely automated. The instrument takes data continuously for over 65 h with a 2.5 h recycle time. The ECS is a nondispersive, broadband, highly efficient spectrometer that is one of the prime instruments at the EBIT facility. The instrument is used for studies of absolute cross sections, charge exchange recombination, and x-ray emission from nonequilibrium plasmas, among other measurements in our laboratory astrophysics program. C1 [Porter, Frederick Scott; Gygax, John; Kelley, Richard L.; Kilbourne, Caroline A.; King, Jonathan M.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Beiersdorfer, Peter; Brown, Gregory V.; Thorn, Daniel B.] Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. [Kahn, Steven M.] Stanford Univ, Dept Phys, Stanford, CA 94305 USA. RP Porter, FS (reprint author), NASA, Goddard Space Flight Ctr, Code 662, Greenbelt, MD 20771 USA. RI Porter, Frederick/D-3501-2012; Kelley, Richard/K-4474-2012; XRAY, SUZAKU/A-1808-2009 OI Porter, Frederick/0000-0002-6374-1119; NR 10 TC 12 Z9 12 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0034-6748 EI 1089-7623 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD OCT PY 2008 VL 79 IS 10 AR 10E307 DI 10.1063/1.2957925 PG 4 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 367ST UT WOS:000260573500065 PM 19044469 ER PT J AU Thorn, DB Gu, MF Brown, GV Beiersdorfer, P Porter, FS Kilbourne, CA Kelley, RL AF Thorn, Daniel B. Gu, Ming F. Brown, Greg V. Beiersdorfer, Peter Porter, F. Scott Kilbourne, Caroline A. Kelley, Richard L. TI High-resolution hard x-ray spectroscopy of high-temperature plasmas using an array of quantum microcalorimeters SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article; Proceedings Paper CT 17th Topical Conference on High-Temperature Plasma Diagnostics CY 2008 CL Albuquerque, NM DE calorimetry; plasma diagnostics ID HELIUM-LIKE KRYPTON; FE-XXV; SPECTROMETER; HYDROGENLIKE; SPECTRA; TRANSITIONS; XENON; LINES AB Quantum microcalorimeters show promise in being able to fully resolve x-ray spectra from heavy highly charged ions, such as would be found in hot plasmas with temperatures in excess of 50 keV. Quantum microcalorimeter arrays are able to achieve this as they have a high-resolving power and good effective quantum efficiency for hard x-ray photons up to 60 keV. To demonstrate this, we present a measurement using an array of thin HgTe quantum microcalorimeters to measure the K-shell spectrum of hydrogenlike through carbonlike praseodymium (Z=57). With this device we are able to attain a resolving power, E/Delta E, of 1000 at a photon energy of 37 keV. C1 [Thorn, Daniel B.; Gu, Ming F.; Brown, Greg V.; Beiersdorfer, Peter] Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. [Porter, F. Scott; Kilbourne, Caroline A.; Kelley, Richard L.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Thorn, Daniel B.] Univ Calif Davis, Dept Appl Sci, Davis, CA 95616 USA. RP Thorn, DB (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RI Porter, Frederick/D-3501-2012; Kelley, Richard/K-4474-2012 OI Porter, Frederick/0000-0002-6374-1119; NR 20 TC 1 Z9 1 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0034-6748 EI 1089-7623 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD OCT PY 2008 VL 79 IS 10 AR 10E323 DI 10.1063/1.2953449 PG 3 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 367ST UT WOS:000260573500081 PM 19044485 ER PT J AU Vance, S Brown, JM AF Vance, Steve Brown, J. Michael TI The simulator for icy world interiors: A 700 MPa pressure system for impulsive stimulated scattering and other optical measurements, with thermal control from-20 to 100 degrees C SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article DE acoustic wave velocity; light propagation; light scattering; optical properties; spectrophotometry; underwater sound ID INACTIVATION; KBAR AB The simulator for icy world interiors (SIWI) was developed for sound velocity measurements in simulated extraterrestrial ocean materials by the method of impulsive stimulated scattering (ISS). The design and operation of SIWI are described. Optical measurements at low temperature in corrosive solution were enabled by enclosing sample fluid in a stoppered spectrophotometric cuvette. To maintain minimum optical density it was necessary to limit contact of the dioctyl sebacate hydraulic fluid with nitrile o-rings, which caused discoloring enhanced absorption of the 532 nm ISS probe pulses. Dilution of hydraulic fluid with kerosene in the amount of 5% by volume prevented clouding at high pressures and at low temperatures. Pure kerosene was found to attenuate the ISS signal, and so was deemed unsatisfactory at low temperatures where the lower thermal expansion of water leads to weaker density contrasts between heated and unheated regions in the sample fluid. When 50 cS silicone oil was used as a hydraulic medium, clouding was observed at pressures above 400 MPa when temperatures were raised above similar to 50 degrees C and lowered to less than similar to 10 degrees C. To our knowledge, such clouding has not been reported previously for dioctyl sebacate, nor for silicone at such low pressures. C1 [Vance, Steve] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Brown, J. Michael] Univ Washington, Seattle, WA 98195 USA. RP Vance, S (reprint author), CALTECH, Jet Prop Lab, MS 183-401,4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM svance@jpl.nasa.gov NR 9 TC 1 Z9 1 U1 0 U2 3 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 OCT PY 2008 VL 79 IS 10 AR 105105 DI 10.1063/1.3000001 PG 5 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 367ST UT WOS:000260573500050 PM 19044744 ER PT J AU Watson, AM Duran-Rojas, MC Stapelfeldt, KR AF Watson, Alan M. Carolina Duran-Rojas, Maria Stapelfeldt, Karl R. TI The photometric variability of HH 30 SO REVISTA MEXICANA DE ASTRONOMIA Y ASTROFISICA LA English DT Article DE accretion, accretion disks; circumstellar matter; stars : individual (HH 30); stars : pre-main sequence ID ORION NEBULA CLUSTER; T-TAURI STARS; SPACED DATA; AA-TAU; ROTATION; CONSTRAINTS; ACCRETION; DISK AB HH 30 is an edge-on disk around a young stellar object. Previous imaging with the Hubble Space Telescope has show morphological variability that is possibly related to the rotation of the star or the disk. We report the results of two terrestrial observing campaigns to monitor the integrated magnitude of HH 30. We use the Lomb-Scargle periodogram to look for periodic modulation with periods between 2 days and almost 90 days in these two data sets and in a third, previously published, data set. We develop a method to deal with short-term correlations in the data. Our results indicate that none of the data sets shows evidence for significant periodic photometric modulation. C1 [Watson, Alan M.; Carolina Duran-Rojas, Maria] Univ Nacl Autonoma Mexico, Ctr Radioastron Astrofis, Morelia 58089, Michoacan, Mexico. [Stapelfeldt, Karl R.] CALTECH, Jet Prop Lab, Pasadena, CA USA. RP Watson, AM (reprint author), Univ Nacl Autonoma Mexico, Ctr Radioastron Astrofis, Apdo Postal 3-72 Xangari, Morelia 58089, Michoacan, Mexico. EM a.watson@astrosmo.unam.mx; c.duran@astrosmo.unam.mx; krs@exoplanet.jpl.nasa.gov RI Stapelfeldt, Karl/D-2721-2012 FU University of Massachusetts; Infrared Processing; Analysis Center at the California Institute of Technology; National Aeronautics and Space Administration; National Science Foundation FX We also used 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 at the California Institute of Technology, funded by the National Aeronautics and Space Administration and the National Science Foundation. NR 22 TC 1 Z9 1 U1 0 U2 1 PU UNIV NACIONAL AUTONOMA MEXICO, INST DE ASTRONOMIA PI MEXICO CITY PA APDO POSTAL 70-264, MEXICO CITY 04510, MEXICO SN 0185-1101 J9 REV MEX ASTRON ASTR JI Rev. Mex. Astron. Astrofis. PD OCT PY 2008 VL 44 IS 2 BP 389 EP 399 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 355WD UT WOS:000259739000013 ER PT J AU Wu, ST Wang, AH Fry, CD Feng, XS Wu, CC Dryer, M AF Wu, S. T. Wang, Ai-Hua Fry, C. D. Feng, XueShang Wu, Chin-Chun Dryer, Murray TI Challenges of modeling solar disturbances' arrival times at the Earth SO SCIENCE IN CHINA SERIES E-TECHNOLOGICAL SCIENCES LA English DT Article DE space weather-magnetohydrodynamic (MHD) modeling; MHD Sun-Earth connection; MHD Sun-Corona ID CORONAL MASS EJECTION; INTERPLANETARY SHOCKS; MAGNETIC CLOUD; MHD; EVOLUTION; EVENT; SIMULATION; PREDICTION AB In recent years remarkable advances have been made in the development of physics based models of various parts of the solar-terrestrial system (see JASTP special issues, October, November 2004; February 2007). In this paper, we focus our discussions in a specific region of the Sun to the Earth's environment (i.e. 1 AU). It is well-known that geomagnetic storms are caused by solar eruptions. The consequences of these storms include particle acceleration, solar wind impact on the Earth's magnetosphere and ionosphere, UV-EUV radiation effects on the lower atmosphere, etc. One of the main challenges is to predict the arrival time at 1 AU of the solar disturbance. The prospects look good for an accurate, real-time forecast scheme built on the acquisition of solar, heliosphere and the near-Earth data and large-scale models. However, the accuracy of these models still needs improvement. We will discuss the present status of the models and challenges to improve the simulation models. C1 [Wu, S. T.; Wang, Ai-Hua; Fry, C. D.; Wu, Chin-Chun; Dryer, Murray] Univ Alabama, Ctr Space Plasma & Aeron Res, Huntsville, AL 35899 USA. [Wu, S. T.] Univ Alabama, Dept Mech & Aerosp Engn, Huntsville, AL 35899 USA. [Fry, C. D.; Dryer, Murray] Explorat Phys Int Inc, Huntsville, AL 35806 USA. [Feng, XueShang] State Key Lab Space Weather, SIGMA Weather Grp, Beijing 100080, Peoples R China. [Feng, XueShang] Ctr Space Sci & Appl Res, Beijing 100080, Peoples R China. [Wu, Chin-Chun] NASA, Goddard Space Flight Ctr, Space Weather Lab, Greenbelt, MD 20771 USA. [Dryer, Murray] NOAA, Space Weather Predict Ctr, Boulder, CO USA. RP Wu, ST (reprint author), Univ Alabama, Ctr Space Plasma & Aeron Res, Huntsville, AL 35899 USA. EM wus@cspar.uah.edu FU AFOSR [A9550-07-1-0468]; AURA Sub-Award [C10569A]; AST [0132798]; NSF [ATM-0754378]; NASA [NNX07AH85G]; ational Natural Science Foundation of China [40536029, 40621003, 40374056, 40574058] FX STW and AHW are supported by AFOSR (Grant No. FA9550-07-1-0468), AURA Sub-Award C10569A of NSO's Cooperative Agreement AST 0132798, and NSF (Grant No. ATM-0754378); CCW is supported by NASA grant NNX07AH85G FENG is supported by National Natural Science Foundation of China (Grant Nos. 40536029, 40621003, 40374056 and 40574058) NR 30 TC 3 Z9 4 U1 0 U2 5 PU SCIENCE PRESS PI BEIJING PA 16 DONGHUANGCHENGGEN NORTH ST, BEIJING 100717, PEOPLES R CHINA SN 1006-9321 J9 SCI CHINA SER E JI Sci. China Ser. E-Technol. Sci. PD OCT PY 2008 VL 51 IS 10 SI SI BP 1580 EP 1588 DI 10.1007/s11431-008-0266-7 PG 9 WC Engineering, Multidisciplinary; Materials Science, Multidisciplinary SC Engineering; Materials Science GA 356PK UT WOS:000259789900003 ER PT J AU Ireland, J Young, CA McAteer, RTJ Whelan, C Hewett, RJ Gallagher, PT AF Ireland, J. Young, C. A. McAteer, R. T. J. Whelan, C. Hewett, R. J. Gallagher, P. T. TI Multiresolution analysis of active region magnetic structure and its correlation with the Mount Wilson classification and flaring activity SO SOLAR PHYSICS LA English DT Article DE Sun : active region; Sun : magnetic field ID FIELD PROPERTIES; SOLAR MAGNETOGRAMS; NEUTRAL-LINE; SEGMENTATION; PRODUCTIVITY; SAMPLE AB Two different multiresolution analyses are used to decompose the structure of active-region magnetic flux into concentrations of different size scales. Lines separating these opposite polarity regions of flux at each size scale are found. These lines are used as a mask on a map of the magnetic field gradient to sample the local gradient between opposite polarity regions of given scale sizes. It is shown that the maximum, average, and standard deviation of the magnetic flux gradient for alpha,beta,beta gamma, and beta gamma delta active-regions increase in the order listed, and that the order is maintained over all length scales. Since magnetic flux gradient is strongly linked to active-region activity, such as flares, this study demonstrates that, on average, the Mt.Wilson classification encodes the notion of activity over all length scales in the active-region, and not just those length scales at which the strongest flux gradients are found. Further, it is also shown that the average gradients in the field, and the average length-scale at which they occur, also increase in the same order. Finally, there are significant differences in the gradient distribution, between flaring and non-flaring active regions, which are maintained over all length scales. It is also shown that the average gradient content of active-regions that have large flares (GOES class "M" and above) is larger than that for active regions containing flares of all flare sizes; this difference is also maintained at all length scales. All of the reported results are independent of the multiresolution transform used. The implications for the Mt. Wilson classification of active-regions in relation to the multiresolution gradient content and flaring activity are discussed. C1 [Ireland, J.; Young, C. A.] NASA, Goddard Space Flight Ctr, ADNET Syst Inc, Greenbelt, MD 20771 USA. [McAteer, R. T. J.] Catholic Univ Amer, NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Whelan, C.] Univ Coll Dublin, Sch Phys, Dublin 4, Ireland. [Hewett, R. J.] Univ Illinois, Dept Comp Sci, Urbana, IL 61801 USA. [Gallagher, P. T.] Univ Dublin Trinity Coll, Sch Phys, Astrophys Res Grp, Dublin 2, Ireland. RP Ireland, J (reprint author), NASA, Goddard Space Flight Ctr, ADNET Syst Inc, Mail Code 671-1, Greenbelt, MD 20771 USA. EM jack.ireland@nasa.gov RI McAteer, R. T. James/D-3736-2011; Gallagher, Peter/C-7717-2011 OI Gallagher, Peter/0000-0001-9745-0400 FU NASA Living With a Star Targeted Research and Technology award [NNH04CC65C] FX This work was supported by NASA Living With a Star Targeted Research and Technology award NNH04CC65C. SOHO is a joint project of international co-operation by ESA and NASA. NR 31 TC 13 Z9 13 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 OCT PY 2008 VL 252 IS 1 BP 121 EP 137 DI 10.1007/s11207-008-9233-5 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 354ZD UT WOS:000259677500009 ER PT J AU Lawrence, JK Cadavid, AC Ruzmaikin, A AF Lawrence, J. K. Cadavid, A. C. Ruzmaikin, A. TI Rotational quasi-periodicities and the Sun-heliosphere connection SO SOLAR PHYSICS LA English DT Article ID SOLAR MAGNETIC-FIELD; ACTIVE LONGITUDES; SECTOR STRUCTURE; EVOLUTION; SERIES AB Mutual quasi-periodicities near the solar-rotation period appear in time series based on the Earth's magnetic field, the interplanetary magnetic field, and signed solar-magnetic fields. Dominant among these is one at 27.03 +/- 0.02 days that has been highlighted by Neugebauer et al. (J. Geophys. Res. 105, 2315, 2000). Extension of their study in time and to different data reveals decadal epochs during which the approximate to 27.0 days, or a approximate to 28.3 days, or other quasi-periods dominate the signal. Space-time eigenvalue analyses of time series in 30 solar latitude bands, based on synoptic maps of unsigned photospheric fields, lead to two maximally independent modes that account for almost 30% of the data variance. One mode spans 45 degrees of latitude in the northern hemisphere and the other one in the southern. The modes rotate around the Sun rigidly, not differentially, suggesting connection with the subsurface dynamo. Spectral analyses yield familiar dominant quasi-periods 27.04 +/- 0.03 days in the North and at 28.24 +/- 0.03 days in the South. These are replaced during cycle 23 by one at 26.45 +/- 0.03 days in the North. The modes show no tendency for preferred longitudes separated by approximate to 180 degrees. C1 [Lawrence, J. K.; Cadavid, A. C.] Calif State Univ Northridge, Dept Phys & Astron, Northridge, CA 91330 USA. [Ruzmaikin, A.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Lawrence, JK (reprint author), Calif State Univ Northridge, Dept Phys & Astron, 18111 Nordhoff St, Northridge, CA 91330 USA. EM john.lawrence@csun.edu; ana.cadavid@csun.edu; alexander.ruzmaikin@jpl.nasa.gov NR 24 TC 9 Z9 9 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 OCT PY 2008 VL 252 IS 1 BP 179 EP 193 DI 10.1007/s11207-008-9237-1 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 354ZD UT WOS:000259677500012 ER PT J AU Pesnell, WD AF Pesnell, William Dean TI Predictions of Solar Cycle 24 SO SOLAR PHYSICS LA English DT Article ID SOLAR-ACTIVITY FORECAST; SUNSPOT NUMBER; MAXIMUM AMPLITUDE; CYCLE; MODEL; SIZE AB A summary and analysis of more than 50 predictions of the amplitude of the upcoming Solar Cycle 24 is presented. All of the predictions were published before solar minimum and represent our efforts to anticipate solar maximum at ever-earlier epochs. The consistency of the predictions within their assigned categories is discussed. Estimates of the significance of the predictions, compared to the climatological average, are presented. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Pesnell, WD (reprint author), NASA, Goddard Space Flight Ctr, Code 671, Greenbelt, MD 20771 USA. EM william.d.pesnell@nasa.gov RI Pesnell, William/D-1062-2012 OI Pesnell, William/0000-0002-8306-2500 NR 58 TC 83 Z9 89 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 OCT PY 2008 VL 252 IS 1 BP 209 EP 220 DI 10.1007/s11207-008-9252-2 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 354ZD UT WOS:000259677500014 ER PT J AU Brown, AD Chuss, D Mikula, V Henry, R Wollack, E Zhao, Y Hilton, GC Chervenak, JA AF Brown, Ari-David Chuss, David Mikula, Vilem Henry, Ross Wollack, Edward Zhao, Yue Hilton, Gene C. Chervenak, James A. TI Auxiliary components for kilopixel transition edge sensor arrays SO SOLID-STATE ELECTRONICS LA English DT Article; Proceedings Paper CT International Semiconductor Device Research Symposium CY DEC 12-14, 2007 CL College Pk, MD DE Resistive elements; Transition edge sensors; Focal plane arrays ID CAMERA; FILMS; TEMPERATURE; FABRICATION; ATMOSPHERE; RESOLUTION; SCUBA-2; MON AB We have fabricated transition edge sensor bolometer focal plane arrays sensitive to mm-submillimeter (0.1-3 THz) radiation for the Atacama Cosmology Telescope (ACT), which will probe the cosmic microwave background at 145, 215, and 280 GHz. Central to the performance of these bolometers is a set of auxiliary resistive components. Here we discuss shunt resistors, which allow for tight optimization of bolometer time constant and sensitivity. Our shunt resistors consist of AuPd strips grown atop interdigitated Superconducting MoNx wires. We can tailor the shunt resistance by altering the dimensions of the AuPd strips and the pitch and width of the MoN, wires and can fabricate all of the shunts necessary for a kilopixel focal plane bolometer array on a single 4" wafer. By modeling the resistance dependence of these parameters, a variety of different 0.75 +/- 0.05 mOhm shunt resistors have been fabricated. This variety includes different shunts which have MoN, wires with wire width equal to 1.5 and 10 mu m and pitch equal to 4.5 and 26 mu m, respectively. Our ability to set the resistance of the shunts hints at the scalability of our design. We have also integrated a SiO2 capping layer into our shunt resistor fabrication scheme, which inhibits metal corrosion and eventual degradation of the shunt. Consequently, their robustness coupled with their high packing density makes these resistive components attractive for future kilopixel detector arrays. (c) 2008 Elsevier Ltd. All rights reserved. C1 [Brown, Ari-David; Chuss, David; Mikula, Vilem; Henry, Ross; Wollack, Edward; Chervenak, James A.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Zhao, Yue] Princeton Univ, Dept Phys, Princeton, NJ 08540 USA. [Hilton, Gene C.] Natl Inst Stand & Technol, Boulder, CO 80303 USA. RP Brown, AD (reprint author), NASA, Goddard Space Flight Ctr, Code 553, Greenbelt, MD 20771 USA. EM Ari.D.Brown@nasa.gov RI Wollack, Edward/D-4467-2012 OI Wollack, Edward/0000-0002-7567-4451 NR 19 TC 3 Z9 4 U1 1 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0038-1101 J9 SOLID STATE ELECTRON JI Solid-State Electron. PD OCT PY 2008 VL 52 IS 10 BP 1619 EP 1624 DI 10.1016/j.sse.2008.06.018 PG 6 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA 370IM UT WOS:000260755900027 ER PT J AU Parro, RJ Scardelletti, MC Varaljay, NC Zimmerman, S Zorman, CA AF Parro, Rocco J. Scardelletti, Maximilian C. Varaljay, Nicholas C. Zimmerman, Sloan Zorman, Christian A. TI Amorphous SiC as a structural layer in microbridge-based RF MEMS switches for use in software-defined radio SO SOLID-STATE ELECTRONICS LA English DT Article; Proceedings Paper CT International Semiconductor Device Research Symposium CY DEC 12-14, 2007 CL College Pk, MD DE PECVD silicon carbide; RF MEMS; Microbridge; Young's modulus; Residual stress ID CHEMICAL VAPOR-DEPOSITION; THIN-FILMS; SILICON-CARBIDE; MECHANICAL-PROPERTIES; YOUNGS MODULUS; BULGE TEST; STRESS; PECVD; RATIO AB This paper reports an effort to develop amorphous silicon carbide (a-SiC) films for use in shunt capacitor RF MEMS microbridge-based switches. The films were deposited using methane and silane as the precursor gases. Switches were fabricated using 500 nm and 300 nm-thick a-SiC films to form the microbridges. Switches made from metallized 500 nm-thick SiC films exhibited favorable mechanical performance but poor RF performance. In contrast, switches made from metallized 300 nm-thick Sic films exhibited excellent RF performance but poor mechanical performance. Load-deflection testing of unmetallized and metallized bulk micromachined Sic membranes indicates that the metal layers have a small effect on the Young's modulus of the 500 nm and 300 nm-thick Sic MEMS. As for residual stress, the metal layers have a modest effect on the 500 nm-thick structures, but a significant affect on the residual stress in the 300 nm-thick structures. (c) 2008 Elsevier Ltd. All rights reserved. C1 [Parro, Rocco J.; Zorman, Christian A.] Case Western Reserve Univ, Dept Elect Engn & Comp Sci, Cleveland, OH 44106 USA. [Scardelletti, Maximilian C.; Varaljay, Nicholas C.] NASA Glenn Res Ctr, Electron & Opt Device Branch, Cleveland, OH USA. [Zimmerman, Sloan] Solon High Sch, Solon, OH USA. RP Zorman, CA (reprint author), Case Western Reserve Univ, Dept Elect Engn & Comp Sci, 715A Glennan Bldg,10900 Euclid Ave, Cleveland, OH 44106 USA. EM rocco.parro@case.edu; christian.zorman@case.edu OI Zorman, Christian/0000-0001-9773-9351 NR 17 TC 11 Z9 11 U1 1 U2 5 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0038-1101 J9 SOLID STATE ELECTRON JI Solid-State Electron. PD OCT PY 2008 VL 52 IS 10 BP 1647 EP 1651 DI 10.1016/j.sse.2008.06.004 PG 5 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA 370IM UT WOS:000260755900031 ER PT J AU Sutton, AK Moen, K Cressler, JD Carts, MA Marshall, PW Pellish, JA Ramachandran, V Reed, RA Alles, ML Nju, G AF Sutton, Akil. K. Moen, Kurt Cressler, John D. Carts, Martin A. Marshall, Paul W. Pellish, Jonathan A. Ramachandran, Vishwa Reed, Robert A. Alles, Michael L. Nju, Guofu TI Proton-induced SEU in SiGe digital logic at cryogenic temperatures SO SOLID-STATE ELECTRONICS LA English DT Article; Proceedings Paper CT International Semiconductor Device Research Symposium CY DEC 12-14, 2007 CL College Pk, MD DE Silicon-germanium; Radiation effects; Single event upset; Proton; Radiation hardening by design RHBD; SEU; SiGe HBT ID HEAVY-ION; RHBD TECHNIQUES; HBT LOGIC; MODEL; UPSET; TRANSISTORS; CIRCUITS; IRRADIATION; ENVIRONMENT; TECHNOLOGY AB We present the first experimental results confirming the increased SEE sensitivity of SiGe digital bipolar logic circuits operating in a 63 MeV proton environment at cryogenic temperatures. A 3x increase in both the error-event and bit-error cross sections is observed as the circuits are cooled from 300 K to 77 K, with error signature analyses indicating corresponding increases in the average number of bits-in-error and error length over data rates ranging from 50 Mbit/s to 4 Gbit/s. Single-bit-errors dominate the proton-induced SEU response at both 300 K and 77 K, as opposed to the multiple-bit-errors seen in the heavy-ion SEU response. Temperature dependent substrate carrier lifetime measurements. when combined with calibrated 2 D DESSIS simulations, suggest that the increased transistor charge collection at low temperature is a mobility driven phenomenon. Circuit-level RHBD techniques are shown to be very efficient in mitigating the proton-induced SEU at both 300 K and 77 K over the data rates tested. These results suggest that the circuit operating temperature must be carefully considered during component qualification for SEE tolerance and indicate the need for broad-beam heavy-ion testing at low temperatures. Published by Elsevier Ltd. C1 [Sutton, Akil. K.; Moen, Kurt; Cressler, John D.] Georgia Inst Technol, Sch Elect & Comp Engn, Atlanta, GA 30332 USA. [Carts, Martin A.] Muniz Engn, Houston, TX 77058 USA. [Marshall, Paul W.] NASA GSFC, Brookneal, VA 24528 USA. [Pellish, Jonathan A.; Ramachandran, Vishwa; Reed, Robert A.; Alles, Michael L.] Vanderbilt Univ, Dept Elect Engn & Comp Sci, Nashville, TN 37235 USA. [Nju, Guofu] Auburn Univ, Dept Elect & Comp Engn, Auburn, AL 36849 USA. RP Sutton, AK (reprint author), Georgia Inst Technol, Sch Elect & Comp Engn, 777 Atlantic Dr,NW, Atlanta, GA 30332 USA. EM asutton@ece.gatech.edu RI Pellish, Jonathan/A-8591-2008; OI Moen, Kurt/0000-0001-7697-8636 NR 40 TC 6 Z9 6 U1 0 U2 5 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0038-1101 J9 SOLID STATE ELECTRON JI Solid-State Electron. PD OCT PY 2008 VL 52 IS 10 BP 1652 EP 1659 DI 10.1016/j.sse.2008.06.038 PG 8 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA 370IM UT WOS:000260755900032 ER PT J AU Ribaya, BP Niemann, DL Makarewicz, J Gunther, NG Nguyen, CV Rahman, M AF Ribaya, Bryan P. Niemann, Darrell L. Makarewicz, Joseph Gunther, Norman G. Nguyen, Cattien V. Rahman, Mahmud TI An empirical study of dynamic properties of an individual carbon nanotube electron source system SO SOLID-STATE ELECTRONICS LA English DT Article; Proceedings Paper CT International Semiconductor Device Research Symposium CY DEC 12-14, 2007 CL College Pk, MD DE Carbon nanotube; Field emission; Dynamic properties; Voltage-controlled variable resistor; Circuit model; Emitter array ID FIELD-EMISSION PROPERTIES; BRIGHTNESS; FILMS; BEAM AB In this paper we present an empirical study of some dynamic properties of an individual carbon nanotube (CNT) field emission electron source system. We propose a circuit model that represents the CNT cathode to anode diode as a capacitor in parallel with a voltage-controlled variable resistor. The transient response of the CNT electron source system to the failing edge of a voltage step input was evaluated. For input voltages below the threshold voltage for field emission, the nanotube loop is effectively open and the circuit response is consistent with a discharging capacitor. On the other hand, for input voltages above field emission threshold. the nanotube loop conducts and now the capacitor discharges to a certain extent through the nanotube loop as well. Field emission current versus voltage data also shows that the resistance across the CNT cathode to anode diode varies as a function of applied voltage. Below turn-on voltage, the diode behaves as art open circuit (4 T Omega at the ammeter noise floor). Above turn-on voltage, resistance falls exponentially, as expected from the Fowler-Nordheim equation for cold field emission current. Experimental current-voltage data is presented for a simple emitter array consisting of two CNTs with equal lengths. Despite the similarity in their lengths the turn-on voltages of the nanotubes varied significantly, viz. 26 V versus 109 V. This large difference in the turn-on voltages can be attributed to tip imperfections. For advanced array applications such as high-throughput parallel e-beam lithography, in which precise dose control is necessary, the diode circuit model will be useful for controlling individually addressed nanotubes to account for dissimilar field emission properties. The model may also be applied to optimize the design of a SEM incorporating a single CNT electron source. (c) 2008 Elsevier Ltd. All rights reserved. C1 [Ribaya, Bryan P.; Niemann, Darrell L.; Gunther, Norman G.; Rahman, Mahmud] Santa Clara Univ, Electron Devices Lab, Santa Clara, CA 95053 USA. [Ribaya, Bryan P.; Niemann, Darrell L.; Makarewicz, Joseph; Nguyen, Cattien V.] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. [Nguyen, Cattien V.] ELORET Corp, Moffett Field, CA 94035 USA. RP Rahman, M (reprint author), Santa Clara Univ, Electron Devices Lab, 500 El Camino Real, Santa Clara, CA 95053 USA. EM mrahman@scu.edu NR 20 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 0038-1101 J9 SOLID STATE ELECTRON JI Solid-State Electron. PD OCT PY 2008 VL 52 IS 10 BP 1680 EP 1686 DI 10.1016/j.sse.2008.06.031 PG 7 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA 370IM UT WOS:000260755900036 ER PT J AU Stern, SA AF Stern, S. Alan TI The New Horizons Pluto Kuiper Belt Mission: An Overview with Historical Context SO SPACE SCIENCE REVIEWS LA English DT Review DE Pluto; New Horizons; Mission; Kuiper belt AB NASA's New Horizons (NH) Pluto-Kuiper Belt (PKB) mission was selected for development on 29 November 2001 following a competitive selection resulting from a NASA mission Announcement of Opportunity. New Horizons is the first mission to the Pluto system and the Kuiper belt, and will complete the reconnaissance of the classical planets. New Horizons was launched on 19 January 2006 on a Jupiter Gravity Assist (JGA) trajectory toward the Pluto system, for a 14 July 2015 closest approach to Pluto; Jupiter closest approach occurred on 28 February 2007. The similar to 400 kg spacecraft carries seven scientific instruments, including imagers, spectrometers, radio science, a plasma and particles suite, and a dust counter built by university students. NH will study the Pluto system over an 8-month period beginning in early 2015. Following its exploration of the Pluto system, NH will go on to reconnoiter one or two 30-50 kilometer diameter Kuiper Belt Objects (KBOs) if the spacecraft is in good health and NASA approves an extended mission. New Horizons has already demonstrated the ability of Principal Investigator (PI) led missions to use nuclear power sources and to be launched to the outer solar system. As well, the mission has demonstrated the ability of non-traditional entities, like the Johns Hopkins Applied Physics Laboratory (JHU/APL) and the Southwest Research Institute (SwRI) to explore the outer solar system, giving NASA new programmatic flexibility and enhancing the competitive options when selecting outer planet missions. If successful, NH will represent a watershed development in the scientific exploration of a new class of bodies in the solar system-dwarf planets, of worlds with exotic volatiles on their surfaces, of rapidly (possibly hydrodynamically) escaping atmospheres, and of giant impact derived satellite systems. It will also provide other valuable contributions to planetary science, including: the first dust density measurements beyond 18 AU, cratering records that shed light on both the ancient and present-day KBO impactor population down to tens of meters, and a key comparator to the puzzlingly active, former dwarf planet (now satellite of Neptune) called Triton which is in the same size class as the small planets Eris and Pluto. C1 NASA, Sci Mission Directorate, Washington, DC 20546 USA. RP Stern, SA (reprint author), NASA, Sci Mission Directorate, 300 E St SW, Washington, DC 20546 USA. EM alan.stern@nasa.gov NR 11 TC 47 Z9 49 U1 3 U2 25 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-6308 J9 SPACE SCI REV JI Space Sci. Rev. PD OCT PY 2008 VL 140 IS 1-4 BP 3 EP 21 DI 10.1007/s11214-007-9295-y PG 19 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 382AP UT WOS:000261577300002 ER PT J AU Young, LA Stern, SA Weaver, HA Bagenal, F Binzel, RP Buratti, B Cheng, AF Cruikshank, D Gladstone, GR Grundy, WM Hinson, DP Horanyi, M Jennings, DE Linscott, IR McComas, DJ McKinnon, WB McNutt, R Moore, JM Murchie, S Olkin, CB Porco, CC Reitsema, H Reuter, DC Spencer, JR Slater, DC Strobel, D Summers, ME Tyler, GL AF Young, Leslie A. Stern, S. Alan Weaver, Harold A. Bagenal, Fran Binzel, Richard P. Buratti, Bonnie Cheng, Andrew F. Cruikshank, Dale Gladstone, G. Randall Grundy, William M. Hinson, David P. Horanyi, Mihaly Jennings, Donald E. Linscott, Ivan R. McComas, David J. McKinnon, William B. McNutt, Ralph Moore, Jeffery M. Murchie, Scott Olkin, Catherine B. Porco, Carolyn C. Reitsema, Harold Reuter, Dennis C. Spencer, John R. Slater, David C. Strobel, Darrell Summers, Michael E. Tyler, G. Leonard TI New Horizons: Anticipated Scientific Investigations at the Pluto System SO SPACE SCIENCE REVIEWS LA English DT Review DE Pluto; Charon; Nix; Hydra; New Horizons ID STELLAR OCCULTATION; PHYSICAL STATE; CHARONS RADIUS; MU-M; ATMOSPHERE; SURFACE; TRITON; ICES; JUPITERS; H2O AB The New Horizons spacecraft will achieve a wide range of measurement objectives at the Pluto system, including color and panchromatic maps, 1.25-2.50 micron spectral images for studying surface compositions, and measurements of Pluto's atmosphere (temperatures, composition, hazes, and the escape rate). Additional measurement objectives include topography, surface temperatures, and the solar wind interaction. The fulfillment of these measurement objectives will broaden our understanding of the Pluto system, such as the origin of the Pluto system, the processes operating on the surface, the volatile transport cycle, and the energetics and chemistry of the atmosphere. The mission, payload, and straw-man observing sequences have been designed to achieve the NASA-specified measurement objectives and maximize the science return. The planned observations at the Pluto system will extend our knowledge of other objects formed by giant impact (such as the Earth moon), other objects formed in the outer solar system (such as comets and other icy dwarf planets), other bodies with surfaces in vapor-pressure equilibrium (such as Triton and Mars), and other bodies with N(2):CH(4) atmospheres (such as Titan, Triton, and the early Earth). C1 [Young, Leslie A.; Stern, S. Alan; Olkin, Catherine B.; Spencer, John R.] SW Res Inst, Boulder, CO USA. [Weaver, Harold A.; Cheng, Andrew F.; McNutt, Ralph; Murchie, Scott] Johns Hopkins Univ, Appl Phys Lab, Laurel, MD USA. [Bagenal, Fran; Horanyi, Mihaly] Univ Colorado, Boulder, CO 80309 USA. [Binzel, Richard P.] MIT, Cambridge, MA 02139 USA. [Buratti, Bonnie] CALTECH, Jet Prop Lab, Pasadena, CA USA. [Cruikshank, Dale; Moore, Jeffery M.] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. [Gladstone, G. Randall; McComas, David J.; Slater, David C.] SW Res Inst, San Antonio, TX USA. [Grundy, William M.] Lowell Observ, Flagstaff, AZ 86001 USA. [Hinson, David P.; Linscott, Ivan R.; Tyler, G. Leonard] Stanford Univ, Stanford, CA 94305 USA. [Jennings, Donald E.; Reuter, Dennis C.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [McKinnon, William B.] Washington Univ, St Louis, MO USA. [Porco, Carolyn C.] Space Sci Inst, Boulder, CO USA. [Reitsema, Harold] Ball Aerosp & Technol Corp, Boulder, CO USA. [Strobel, Darrell] Johns Hopkins Univ, Baltimore, MD USA. [Summers, Michael E.] George Mason Univ, Fairfax, VA 22030 USA. RP Young, LA (reprint author), SW Res Inst, Boulder, CO USA. EM layoung@boulder.swri.edu RI McNutt, Ralph/E-8006-2010; Jennings, Donald/D-7978-2012; Murchie, Scott/E-8030-2015; Weaver, Harold/D-9188-2016; OI McNutt, Ralph/0000-0002-4722-9166; Murchie, Scott/0000-0002-1616-8751; Horanyi, Mihaly/0000-0002-5920-9226 FU NASA; NSF FX The authors acknowledge the work of the cast of scientists who have studied the Pluto system, and the numerous NASA and NSF grants and telescope allocations that have supported this work. We are grateful to be working with each of the engineers on the New Horizons project. Finally, the authors thank the public and the scientific community alike for their sustained interest in Pluto and the Pluto system that has made this mission possible. NR 79 TC 36 Z9 36 U1 0 U2 15 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-6308 J9 SPACE SCI REV JI Space Sci. Rev. PD OCT PY 2008 VL 140 IS 1-4 BP 93 EP 127 DI 10.1007/s11214-008-9462-9 PG 35 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 382AP UT WOS:000261577300006 ER PT J AU Reuter, DC Stern, SA Scherrer, J Jennings, DE Baer, JW Hanley, J Hardaway, L Lunsford, A McMuldroch, S Moore, J Olkin, C Parizek, R Reitsma, H Sabatke, D Spencer, J Stone, J Throop, H Van Cleve, J Weigle, GE Young, LA AF Reuter, Dennis C. Stern, S. Alan Scherrer, John Jennings, Donald E. Baer, James W. Hanley, John Hardaway, Lisa Lunsford, Allen McMuldroch, Stuart Moore, Jeffrey Olkin, Cathy Parizek, Robert Reitsma, Harold Sabatke, Derek Spencer, John Stone, John Throop, Henry Van Cleve, Jeffrey Weigle, Gerald E. Young, Leslie A. TI Ralph: A Visible/Infrared Imager for the New Horizons Pluto/Kuiper Belt Mission SO SPACE SCIENCE REVIEWS LA English DT Review DE New Horizons; Pluto/Charon; Kuiper Belt; Ralph; Multi-spectral imager; Infrared spectral imager; Hyperspectral imager; Wedged filter; TDI AB The New Horizons instrument named Ralph is a visible/near infrared multi-spectral imager and a short wavelength infrared spectral imager. It is one of the core instruments on New Horizons, NASA's first mission to the Pluto/Charon system and the Kuiper Belt. Ralph combines panchromatic and color imaging capabilities with SWIR imaging spectroscopy. Its primary purpose is to map the surface geology and composition of these objects, but it will also be used for atmospheric studies and to map the surface temperature. It is a compact, low-mass (10.5 kg) power efficient (7.1 W peak), and robust instrument with good sensitivity and excellent imaging characteristics. Other than a door opened once in flight, it has no moving parts. These characteristics and its high degree of redundancy make Ralph ideally suited to this long-duration flyby reconnaissance mission. C1 [Reuter, Dennis C.; Jennings, Donald E.; Lunsford, Allen] NASA, GSFC, Greenbelt, MD 20771 USA. [Stern, S. Alan] SW Res Inst, Space Sci & Engn Div, Boulder, CO 80302 USA. [Scherrer, John; Hanley, John; Stone, John; Weigle, Gerald E.] SwRI, San Antonio, TX 78228 USA. [Baer, James W.; Hardaway, Lisa; Parizek, Robert; Reitsma, Harold; Sabatke, Derek; Van Cleve, Jeffrey] Ball Aerosp & Technol Corp, Boulder, CO 80301 USA. [McMuldroch, Stuart] SSG Precis Optron, Wilmington, MA 01887 USA. [Moore, Jeffrey] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. [Olkin, Cathy; Spencer, John; Throop, Henry; Young, Leslie A.] SW Res Inst, Dept Space Studies, Boulder, CO 80302 USA. RP Reuter, DC (reprint author), NASA, GSFC, Code 693, Greenbelt, MD 20771 USA. EM dennis.c.reuter@nasa.gov RI Jennings, Donald/D-7978-2012 FU JDSU/Uniphase; E2V; Barr Associates; Corning Diamond Turning Division; Teledyne FX The authors would like to thank the entire Ralph support teams at BATC and SwRI and the LEISA support team at GSFC for their untiring efforts in making Ralph a reality. The contributions of JDSU/Uniphase, E2V, Barr Associates, Corning Diamond Turning Division and Teledyne are also gratefully acknowledged. NR 9 TC 29 Z9 29 U1 0 U2 12 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-6308 J9 SPACE SCI REV JI Space Sci. Rev. PD OCT PY 2008 VL 140 IS 1-4 BP 129 EP 154 DI 10.1007/s11214-008-9375-7 PG 26 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 382AP UT WOS:000261577300007 ER PT J AU Tremolet, Y AF Tremolet, Yannick TI Computation of observation sensitivity and observation impact in incremental variational data assimilation SO TELLUS SERIES A-DYNAMIC METEOROLOGY AND OCEANOGRAPHY LA English DT Article ID ADJOINT; 4D-VAR; APPROXIMATIONS; CONVERGENCE; SYSTEM; MODEL AB We discuss the computation of observation sensitivities and observation impact for incremental variational data assimilation (VDA), accounting for the inner and outer loops. To fully account for the outer loops, a second-order adjoint of the data assimilation system is required, which makes it impractical for an operational data assimilation system. However, some approximations can be made that allow useful results to be obtained with multiple outer loop iterations, in particular, for observation impact studies. Two algorithms are presented to compute the adjoint of the inner loop minimization, and their merits are discussed. Validation results are given for both of these algorithms. We show that one algorithm, based on the adjoint of an approximation of the inverse of the Hessian of the cost function, can also be used to investigate some convergence aspects of the incremental VDA inner loop. Because it is computationally inexpensive, the proposed algorithm could be used to monitor an operational system routinely. We give some numerical results illustrating the impact of observations in successive outer loop iterations. C1 NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Greenbelt, MD 20771 USA. RP Tremolet, Y (reprint author), NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Code 610-1, Greenbelt, MD 20771 USA. EM ytremolet@gmao.gsfc.nasa.gov NR 21 TC 29 Z9 29 U1 0 U2 1 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0280-6495 J9 TELLUS A JI Tellus Ser. A-Dyn. Meteorol. Oceanol. PD OCT PY 2008 VL 60 IS 5 BP 964 EP 978 DI 10.1111/j.1600-0870.2008.00349.x PG 15 WC Meteorology & Atmospheric Sciences; Oceanography SC Meteorology & Atmospheric Sciences; Oceanography GA 352VX UT WOS:000259526600013 ER PT J AU Ma, W Tavakoli, T Chen, S Maric, D Liu, JL O'Shaughnessy, TJ Barker, JL AF Ma, Wu Tavakoli, Tahereh Chen, Silvia Maric, Dragan Liu, Jinny L. O'Shaughnessy, Thomas J. Barker, Jeffery L. TI Reconstruction of Functional Cortical-like Tissues from Neural Stem and Progenitor Cells SO TISSUE ENGINEERING PART A LA English DT Article ID 3-DIMENSIONAL COLLAGEN GELS; PRECURSOR CELLS; DIFFERENTIATION; RAT; GROWTH; PROLIFERATION; MICROGRAVITY; BIOREACTOR; NEURONS; CULTURE AB Neural stem and progenitor cells isolated from embryonic day 13 rat cerebral cortex were immobilized in three-dimensional type I collagen gels, and then the cell-collagen constructs were transferred to rotary wall vessel bioreactors and cultured in serum-free medium containing basic fibroblast growth factor (bFGF) combined with brain-derived neurotrophic factor for up to 10 weeks. Remarkably, the collagen-entrapped cells formed a complex two-layered structure that emulated to a certain extent the cerebral cortex of the embryonic brain in architecture and functionality. The surface layer (layer I) composed primarily of proliferating neural progenitor cells (nestin(+), vimentin(+), and PCNA(+)) predominantly expressed functional neurotransmitter receptors for cholinergic and purinergic agonists while differentiating cells (TuJ1(+) and GFAP(+)) in the deeper layer (layer II) contained differentiated neurons and astrocytes and mainly responded to GABAergic and glutamatergic agonists and to veratridine, which activates voltage-dependent Na(+) channels. An active synaptic vesicle recycling was demonstrated by neuronal networks in the deeper layer using the endocytotic marker FM1-43. Cell polarization forming the characteristic two-layered structure was found to associate with the bFGF and FGF receptor signaling. These engineered functional tissue constructs have a potential use as tissue surrogates for drug screening and detection of environmental toxins, and in neural cell replacement therapy. C1 [Ma, Wu; Tavakoli, Tahereh] Amer Type Culture Collect, Stem Cell Ctr, Manassas, VA 20110 USA. [Ma, Wu; Liu, Jinny L.; O'Shaughnessy, Thomas J.] USN, Res Lab, Ctr Biomol Sci & Engn, Washington, DC 20375 USA. [Chen, Silvia] NICHHD, NIH, NASA, Ctr Tissue Culture 3D, Bethesda, MD 20892 USA. [Maric, Dragan; Barker, Jeffery L.] Natl Inst Neurol Disorders & Stroke, NIH, Neurophysiol Lab, Bethesda, MD USA. RP Ma, W (reprint author), Amer Type Culture Collect, Stem Cell Ctr, 10801 Univ Blvd, Manassas, VA 20110 USA. EM wma@atcc.org FU NASA [NRA 00-HEDS-03-136] FX This work was supported in part by NASA grant NRA 00-HEDS-03-136 to W. Ma. The opinions and assertions contained herein are the private ones of the authors and are not to be construed as official or reflecting the views of the Department of the Navy. NR 33 TC 20 Z9 20 U1 0 U2 6 PU MARY ANN LIEBERT INC PI NEW ROCHELLE PA 140 HUGUENOT STREET, 3RD FL, NEW ROCHELLE, NY 10801 USA SN 1937-3341 J9 TISSUE ENG PT A JI Tissue Eng. Part A PD OCT PY 2008 VL 14 IS 10 BP 1673 EP 1686 DI 10.1089/ten.tea.2007.0357 PG 14 WC Cell & Tissue Engineering; Biotechnology & Applied Microbiology; Cell Biology SC Cell Biology; Biotechnology & Applied Microbiology GA 359OS UT WOS:000259998000009 PM 18601590 ER PT J AU Wang, JJ Adler, RF Gu, GJ AF Wang, Jian-Jian Adler, Robert F. Gu, Guojun TI Tropical rainfall-surface temperature relations using Tropical Rainfall Measuring Mission precipitation data SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SOUTHERN-OSCILLATION; PROFILING ALGORITHM; RADAR; TRMM; SENSITIVITY; SATELLITE; EVOLUTION; ORBIT; ENSO AB In this study, 9 years (1998-2006) of monthly precipitation data from Tropical Rainfall Measuring Mission (TRMM) are used to examine the relations between tropical rainfall and surface temperature using measurements from both passive and active microwave sensors. These relations are compared to those derived from Global Precipitation Climatology Project (GPCP) analyses. A technique is first developed to adjust the TRMM Precipitation Radar (PR) monthly rainfall data in the tropics (whole ocean and whole land) to account for the effect of the TRMM orbit boost from 350 to 402 km in August 2001. The postboost PR rainfall is adjusted by adding 6.5, 6.0, and 1.0% to the monthly PR rainfall data over the ocean at the estimated surface, the near surface, and the 2 km level, respectively. No adjustment is made for data over land or above the 4 km level. The relationships between the tropical rainfall and surface temperature are then examined with both the TRMM Microwave Imager (TMI) and adjusted PR data. Comparing tropical (25 degrees N-25 degrees S) ocean precipitation to mean sea surface temperature (SST) over the same area, the GPCP and TMI rainfall data have large and similar slopes (similar to 15%/degrees C) against ocean-wide SST anomalies, while the surface monthly rainfall anomalies derived from the TRMM PR exhibit much shallower slopes (similar to 4%/degrees C) against the SST anomalies. At the 4 km level the PR data exhibit a larger slope (12%/degrees C) comparable to the passive microwave value. Over the tropical land, all rainfall data except TRMM PR at 6 km have similar, but negative, slopes against surface temperature anomalies, in contrast to the positive slopes over the ocean. Over the total tropics (ocean and land combined), TRMM TMI and GPCP rainfall data have rather similar smaller positive slopes (6%/degrees C), when compared to ocean plus land surface temperature, but the PR rainfall data slopes are slightly negative, except at the 4 km level (4%/degrees C). Overall, the PR-based surface precipitation-temperature slopes do not confirm slopes based on passive microwave observations. This may be the result of PR retrieval error or inherent passive/active retrieval differences. Further research is needed to advance the use of TRMM data in this regard. C1 [Wang, Jian-Jian; Adler, Robert F.; Gu, Guojun] NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. [Wang, Jian-Jian; Gu, Guojun] Univ Maryland Baltimore Cty, Goddard Ctr Earth Sci & Technol, Catonsville, MD USA. [Adler, Robert F.] Univ Maryland, Earth Syst Sci Interdisciplinary Ctr, College Pk, MD 20742 USA. RP Wang, JJ (reprint author), NASA, Goddard Space Flight Ctr, Atmospheres Lab, Code 613-1, Greenbelt, MD 20771 USA. EM jjwang@agnes.gsfc.nasa.gov NR 23 TC 7 Z9 7 U1 0 U2 4 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 SEP 30 PY 2008 VL 113 IS D18 AR D18115 DI 10.1029/2007JD009540 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 356US UT WOS:000259803700001 ER PT J AU Thorpe, JI Numata, K Livas, J AF Thorpe, J. I. Numata, K. Livas, J. TI Laser frequency stabilization and control through offset sideband locking to optical cavities SO OPTICS EXPRESS LA English DT Article ID SPECTRAL-PURITY LASER; PHASE AB We describe a class of techniques whereby a laser frequency can be stabilized to a fixed optical cavity resonance with an adjustable offset, providing a wide tuning range for the central frequency. These techniques require only minor modifications to the standard Pound-Drever-Hall locking techniques and have the advantage of not altering the intrinsic stability of the frequency reference. We discuss the expected performance and limitations of these techniques and present a laboratory investigation in which both the sideband techniques and the standard, non-tunable Pound-Drever-Hall technique reached the 100Hz/root Hz level. C1 [Thorpe, J. I.; Numata, K.; Livas, J.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Numata, K.] Univ Maryland, Dept Astron, College Pk, MD 20742 USA. RP Thorpe, JI (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. EM James.I.Thorpe@nasa.gov RI Livas, Jeffrey/D-2994-2012; Thorpe, James/D-3150-2012 FU Goddard Space Flight Center; NASA 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. NR 15 TC 23 Z9 23 U1 2 U2 19 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1094-4087 J9 OPT EXPRESS JI Opt. Express PD SEP 29 PY 2008 VL 16 IS 20 BP 15980 EP 15990 DI 10.1364/OE.16.015980 PG 11 WC Optics SC Optics GA 360XK UT WOS:000260091300071 PM 18825236 ER PT J AU Garay, MJ de Szoeke, SP Moroney, CM AF Garay, Michael J. de Szoeke, Simon P. Moroney, Catherine M. TI Comparison of marine stratocumulus cloud top heights in the Southeastern Pacific retrieved from satellites with coincident ship-based observations SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID IMAGING SPECTRORADIOMETER MISR; BOUNDARY-LAYER; MODIS; ISCCP; TEMPERATURE; VARIABILITY; MOTION AB In order to better understand the general problem of satellite cloud top height retrievals for low clouds, observations made by NOAA research vessels in the stratocumulus region in the southeastern Pacific during cruises in 2001 and 2003 to 2006 were matched with near-coincident retrievals from the Moderate Resolution Imaging Spectroradiometer (MODIS) and Multiangle Imaging SpectroRadiometer (MISR) instruments on the Terra satellite, along with a limited set of ISCCP 30-km (DX) retrievals. The ISCCP cloud top heights, determined from the cloud top pressures, were found to be biased high by between 1400 and 2000 m within the limited comparison data set. Like the International Satellite Cloud Climatology Project (ISCCP) results, the MODIS retrievals were biased high by more than 2000 m, while the MISR retrievals had errors on the order of 230 to 420 m, with the wind corrected heights having almost no bias. The extremely large bias in the ISCCP and MODIS retrievals was traced to their reliance on low-resolution observations or models of the atmospheric temperature structure. Cloud top height retrievals based on satellite cloud top temperatures and a constant atmospheric lapse rate agreed substantially better with the ship-based measurements. C1 [Garay, Michael J.] Raytheon Corp, Intelligence & Informat Syst, Pasadena, CA 91101 USA. [Moroney, Catherine M.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [de Szoeke, Simon P.] Univ Hawaii, Sch Ocean & Earth Sci & Technol, Int Pacific Res Ctr, Honolulu, HI 96822 USA. RP Garay, MJ (reprint author), Raytheon Corp, Intelligence & Informat Syst, 299 N Euclid Ave,Suite 500, Pasadena, CA 91101 USA. EM michael.j.garay@jpl.nasa.gov NR 40 TC 51 Z9 51 U1 0 U2 5 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 SEP 27 PY 2008 VL 113 IS D18 AR D18204 DI 10.1029/2008JD009975 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 353YW UT WOS:000259607100004 ER PT J AU Wu, SL Mickley, LJ Jacob, DJ Rind, D Streets, DG AF Wu, Shiliang Mickley, Loretta J. Jacob, Daniel J. Rind, David Streets, David G. TI Effects of 2000-2050 changes in climate and emissions on global tropospheric ozone and the policy-relevant background surface ozone in the United States SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID LIGHTNING DISTRIBUTIONS; ATMOSPHERIC CHEMISTRY; ISOPRENE EMISSION; MODEL; NOX; AIR; SIMULATIONS; TRANSPORT; METHANE; IMPACT AB We use a global chemical transport model (GEOS-Chem) driven by a general circulation model (NASA Goddard Institute for Space Studies GCM) to investigate the effects of 2000-2050 global change in climate and emissions (the Intergovernmental Panel on Climate Change A1B scenario) on the global tropospheric ozone budget and on the policy-relevant background (PRB) ozone in the United States. The PRB ozone, defined as the ozone that would be present in U. S. surface air in the absence of North American anthropogenic emissions, has important implications for setting national air quality standards. We examine separately and then together the effects of changes in climate and anthropogenic emissions of ozone precursors. We find that the 2000 2050 change in global anthropogenic emissions of ozone precursors increases the global tropospheric ozone burden by 17%. The 2000-2050 climate change increases the tropospheric ozone burden by 1.6%, due mostly to lightning in the upper troposphere, and also increases global tropospheric OH by 12%. In the lower troposphere, by contrast, climate change generally decreases the background ozone. The 2000-2050 increase in global anthropogenic emissions of ozone precursors increases PRB ozone by 2-6 ppb in summer; the maximum effect is found in April (3-7 ppb). The summertime PRB ozone decreases by up to 2 ppb with 2000-2050 climate change, except over the Great Plains, where it increases slightly as a result of increasing soil NOx emission. Climate change cancels out the effect of rising global anthropogenic emissions on the summertime PRB ozone in the eastern United States, but there is still a 2-5 ppb increase in the west. C1 [Wu, Shiliang; Mickley, Loretta J.; Jacob, Daniel J.] Harvard Univ, Dept Earth & Planetary Sci, Cambridge, MA 02138 USA. [Rind, David] NASA, Goddard Inst Space Studies, New York, NY 10025 USA. [Streets, David G.] Argonne Natl Lab, Argonne, IL 60439 USA. [Wu, Shiliang; Mickley, Loretta J.; Jacob, Daniel J.] Harvard Univ, Sch Engn & Appl Sci, Cambridge, MA 02138 USA. RP Wu, SL (reprint author), Harvard Univ, Dept Earth & Planetary Sci, 20 Oxford St, Cambridge, MA 02138 USA. EM s.wu@post.harvard.edu RI Mickley, Loretta/D-2021-2012; Chem, GEOS/C-5595-2014; OI Mickley, Loretta/0000-0002-7859-3470; Streets, David/0000-0002-0223-1350 FU U. S. EPA STAR Program FX This work was supported by the U. S. EPA STAR Program. We thank Arlene Fiore (NOAA GFDL) for help in processing the emission growth factors. NR 76 TC 62 Z9 63 U1 3 U2 26 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 SEP 27 PY 2008 VL 113 IS D18 AR D18312 DI 10.1029/2007JD009639 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 353YW UT WOS:000259607100002 ER PT J AU Baptista, AR Mangold, N Ansan, V Baratoux, D Lognonne, P Alves, EI Williams, DA Bleacher, JE Masson, P Neukum, G AF Baptista, Ana Rita Mangold, Nicolas Ansan, Veronique Baratoux, David Lognonne, Philippe Alves, Eduardo I. Williams, David A. Bleacher, Jacob E. Masson, Philippe Neukum, Gerhard TI A swarm of small shield volcanoes on Syria Planum, Mars SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID ORBITER LASER ALTIMETER; ALBA-PATERA; EFFUSION RATES; RHEOLOGICAL PROPERTIES; TECTONIC HISTORY; THARSIS REGION; LAVA FLOWS; ERUPTION; EVOLUTION; MONS AB This study focuses on the volcanism in Syria Planum, located at the center of the Tharsis bulge at an altitude of 6 to 8 km above Mars datum. Syria Planum was previously recognized as a center for the tectonic activity of Tharsis, but not as a major locus for volcanic activity, despite its centrality over the bulge. Using high-resolution images from the high resolution stereo camera on Mars Express combined with Mars Observer Laser Altimeter data, we have characterized a volcanic system that reveals a number of very interesting aspects of Mars volcanism. We identified a swarm of tens of coalesced shallow volcanic edifices, typically 10-30 km diameter, 0.1-0.2 km high, and with slopes around 0.5 degrees. These characteristics are similar to those of small shield volcanoes found in Iceland. In addition, an intermediate- sized volcano, which is the source of lava flows that extend over >200 km, is observed west of this shield swarm. Our study characterizes a previously unrecognized volcanic assemblage on Mars which appears to be much more developed than was documented before, in terms of morphology, inferred origin, and periodicity of eruption. The estimated lava flux of the Syria Planum volcanoes is of the same order as the lava flux of Tharsis Montes. These characteristics suggest that Syria Planum experienced a very specific style of volcanism, which we dated to the Hesperian period. C1 [Baptista, Ana Rita; Lognonne, Philippe] Inst Phys Globe, F-94107 St Maur Des Fosses, France. [Alves, Eduardo I.] Univ Coimbra, Ctr Geofis, P-3000134 Coimbra, Portugal. [Mangold, Nicolas; Ansan, Veronique; Masson, Philippe] Univ Paris 11, IDES, F-91405 Orsay, France. [Baratoux, David] Univ Toulouse 3, Observ Midi Pyrenees, UMR5562, Lab Dynam Terr & Planetaire, F-31400 Toulouse, France. [Bleacher, Jacob E.] NASA, Goddard Space Flight Ctr, Planetary Geodynam Lab, Greenbelt, MD 20771 USA. [Neukum, Gerhard] Free Univ Berlin, Inst Geol Wissensch, D-12249 Berlin, Germany. [Williams, David A.] Arizona State Univ, Sch Earth & Space Explorat, Tempe, AZ 85287 USA. RP Baptista, AR (reprint author), Inst Phys Globe, 4 Ave Neptune, F-94107 St Maur Des Fosses, France. EM baptista@ipgp.jussieu.fr RI Bleacher, Jacob/D-1051-2012; Baratoux, David/H-6006-2012; Lognonne, Philippe/F-8846-2010; Alves, Eduardo/J-5327-2016; OI Bleacher, Jacob/0000-0002-8499-4828; Baratoux, David/0000-0002-1785-5262; Alves, Eduardo Ivo/0000-0003-4258-588X FU FCT (Foundation for the Science and Technology, on the QCA III European Community Support Program for 2000-2010 in Portugal); Institut National des Sciences de l'Univers (INSU); Centre National d'Etudes Spatiales (CNES) FX We wish to thank J. Plescia, J. M. Byrnes, L. Keszthelyi, and an anonymous reviewer for careful and constructive reviews, H. Massol for her comments, and R. Bulow for the English corrections. We acknowledge the HRSC experiment teams for their successful planning, acquisition, and making the processed data available to the HRSC team. This work is supported by a FCT (Foundation for the Science and Technology, on the QCA III European Community Support Program for 2000-2010 in Portugal) grant to A. R. B. and grants from the Programme National de Planetologie (PNP) of Institut National des Sciences de l'Univers (INSU) and Centre National d'Etudes Spatiales (CNES) for French authors. NR 64 TC 19 Z9 19 U1 0 U2 13 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 SEP 26 PY 2008 VL 113 IS E9 AR E09010 DI 10.1029/2007JE002945 PG 19 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 353ZD UT WOS:000259607800001 ER PT J AU Li, ZXA Lee, CTA Peslier, AH Lenardic, A Mackwell, SJ AF Li, Zheng-Xue Anser Lee, Cin-Ty A. Peslier, Anne H. Lenardic, Adrian Mackwell, Stephen J. TI Water contents in mantle xenoliths from the Colorado Plateau and vicinity: Implications for the mantle rheology and hydration-induced thinning of continental lithosphere SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Review ID SOUTHWESTERN UNITED-STATES; MIDOCEAN RIDGE BASALTS; EARTHS UPPER-MANTLE; NOMINALLY ANHYDROUS MINERALS; NORTH-AMERICAN LITHOSPHERE; SINO-KOREAN CRATON; ORTHO-PYROXENE; MEGACRYSTALLINE NODULES; PERIDOTITE XENOLITHS; 4-PHASE LHERZOLITES AB Nominally anhydrous minerals (e.g., olivine, clinopyroxene, and orthopyroxene) in peridotite xenoliths collected from the Colorado Plateau and southern Basin and Range in western North America were systematically analyzed by Fourier transform infrared spectroscopy for water contents. Measured water contents range from 2 to 45 ppm for olivine, from 53 to 402 ppm for orthopyroxene, and from 171 to 957 ppm for clinopyroxene. The Colorado Plateau has the highest water contents (up to 45 ppm H2O in olivine, 402 ppm H2O in orthopyroxene, and 957 ppm H2O in clinopyroxene), while San Carlos in the southern Basin and Range has the lowest water contents (up to 4 ppm H2O in olivine, 82 ppm H2O in orthopyroxene, and 178 ppm H2O in clinopyroxene). With the exception of San Carlos, the olivine and pyroxenes from all other localities (Dish Hill, Grand Canyon, and Navajo) have water contents close to or higher than that inferred for the fertile asthenospheric mantle. We interpret the high water contents measured here to have been introduced into the base of the lithospheric mantle by rehydration associated with the subduction of the Farallon plate beneath North America during the early Cenozoic. Application of an updated flow law for dislocation creep of wet olivine to lithospheric mantle conditions beneath the Colorado Plateau predicts that for a given background shear stress, hydration alone can result in approximately 1 order of magnitude drop in the effective viscosity at the base of the lithosphere. If viscosity alone is used to distinguish the lithosphere from underlying asthenosphere, this suggests that hydration could have resulted in more than 10 km of lithospheric thinning. Viscosity reduction and lithospheric thinning of even larger extents (up to similar to 100 km) are predicted when thicker lithosphere (such as Archean cratons) and larger water contents (up to water-saturated conditions) are considered. If our interpretations are correct, the implications of our study go beyond western North America and hint at a possible way of recycling continental mantle, including cratonic mantle, back into the convecting mantle. C1 [Li, Zheng-Xue Anser; Lee, Cin-Ty A.; Lenardic, Adrian] Rice Univ, Dept Earth Sci, Houston, TX 77005 USA. [Mackwell, Stephen J.] Lunar & Planetary Inst, Houston, TX 77058 USA. [Peslier, Anne H.] ESCG, Houston, TX 77058 USA. [Peslier, Anne H.] NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. RP Li, ZXA (reprint author), Rice Univ, Dept Earth Sci, 6100 Main St, Houston, TX 77005 USA. EM zxli@rice.edu RI Lee, Cin-Ty/A-5469-2008; Lenardic, Adrian /A-2547-2011; Peslier, Anne/F-3956-2010; Mackwell, Stephen/H-2772-2013; OI Mackwell, Stephen/0000-0002-0996-1348 NR 126 TC 101 Z9 108 U1 0 U2 36 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 SEP 26 PY 2008 VL 113 IS B9 AR B09210 DI 10.1029/2007JB005540 PG 22 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 353ZI UT WOS:000259608300005 ER PT J AU Di, LP Chen, AJ Yang, WL Liu, Y Wei, YX Mehrotra, P Hu, CM Williams, D AF Di, Liping Chen, Aijun Yang, Wenli Liu, Yang Wei, Yaxing Mehrotra, Piyush Hu, Chaumin Williams, Dean TI The development of a geospatial data Grid by integrating OGC Web services with Globus-based Grid technology SO CONCURRENCY AND COMPUTATION-PRACTICE & EXPERIENCE LA English DT Article; Proceedings Paper CT GIS-Grid Workshop at Open Grid Forum CY OCT 03-06, 2005 CL Boston, MA DE geospatial data; interoperability; geospatial Grid; OGC; Globus; NWGISS AB Geospatial science is the science and art of acquiring, archiving, manipulating, analyzing, communicating, modeling with, and utilizing spatially explicit data for understanding physical, chemical, biological, and social systems on the Earth's surface or near the surface. In order to share distributed geospatial resources and facilitate the interoperability, the Open Geospatial Consortium (OGC), in industry-government-academia consortium, has developed a set of widely accepted Web-based interoperability standards and protocols. Grid is the technology enabling resource sharing and coordinated problem solving in dynamic, raulti-institutional virtual organizations. Geospatiall (;rid is an extension and applicalion of Grid technology in the geospatial discipline. This paper discusses problems associated with directly using Globus-based Grid technology in the geospatial disciplines, the needs for geospatial Grids, and the Natures of geospatial Grids. Then, the paper presents a research project that develops and deploys a geospatial Grid through integrating Web-based geospatial interoperability standards and technology developed by OGC with Globus-based Grid technology. The geospatial Grid technology developed by this project makes the interoperable, personalized, on-demand data access and services a reality at large geospatial data archives. Such a technology can significantly reduce problems associated with archiving, manipulating, analyzing and utilizing large volumes of geospatial data at distributed locations. Copyright (C) 2008 John Wiley & Sons, Ltd. C1 [Di, Liping; Chen, Aijun; Yang, Wenli; Liu, Yang; Wei, Yaxing] George Mason Univ, CSISS, Greenbelt, MD 20770 USA. [Mehrotra, Piyush; Hu, Chaumin] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. [Williams, Dean] DOE Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Di, LP (reprint author), George Mason Univ, CSISS, 6301 Ivy Lane,Suite 620, Greenbelt, MD 20770 USA. EM ldi@gmu.edu RI Wei, Yaxing/K-1507-2013 OI Wei, Yaxing/0000-0001-6924-0078 NR 35 TC 19 Z9 21 U1 1 U2 3 PU JOHN WILEY & SONS LTD PI CHICHESTER PA THE ATRIUM, SOUTHERN GATE, CHICHESTER PO19 8SQ, W SUSSEX, ENGLAND SN 1532-0626 J9 CONCURR COMP-PRACT E JI Concurr. Comput.-Pract. Exp. PD SEP 25 PY 2008 VL 20 IS 14 BP 1617 EP 1635 DI 10.1002/cpe.1292 PG 19 WC Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA 354SV UT WOS:000259660200002 ER PT J AU Hatamleh, O AF Hatamleh, Omar TI Effects of peening on mechanical properties in friction stir welded 2195 aluminum alloy joints SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE friction stir welding; laser peening; shot peening; mechanical properties; 2195 ID FATIGUE-CRACK-GROWTH; ALUMINUM-ALLOYS; RESIDUAL-STRESSES; LASER; BEHAVIOR; MICROSTRUCTURE; CORROSION; LITHIUM AB The effects of surface treatment techniques like laser and shot peening on the mechanical properties were investigated for friction stir welded 2195 aluminum alloy joints. The loading in the tensile specimens was applied in a direction perpendicular to the weld direction. The peening effects on the local mechanical properties through the different regions of the weld were characterized using a digital image correlation technique assuming an iso-stress condition. This assumption implies that the stress is uniform over the cross-section and is equal to the average stress. The surface strain and average stress were used giving an average stress-strain curve over the region of interest. The extension of the iso-stress assumption to calculate local stress-strain curves in surface treated regions is a novel approach and will help to understand and improve the local behavior at various regions across the weld resulting in a sound welding process. The surface and through-thickness residual stresses were also assessed using the X-ray diffraction and the contour methods. The laser peened samples displayed approximately 60% increase in the yield strength of the material. In contrast, shot peening exhibited only modest improvement to the tensile properties when compared to the unpeened FSW specimens. The result that laser peening is superior to shot peening because of the depth of penetration is original since this superiority has not been presented before regarding mechanical properties performance. Published by Elsevier B.V. C1 NASA, Lyndon B Johnson Space Ctr, Struct Branch, Houston, TX 77058 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 36 TC 33 Z9 35 U1 4 U2 21 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD SEP 25 PY 2008 VL 492 IS 1-2 BP 168 EP 176 DI 10.1016/j.msea.2008.03.017 PG 9 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 340KM UT WOS:000258644500023 ER PT J AU Kouveliotou, C AF Kouveliotou, Chryssa TI Astrophysics - How fast can you blink? SO NATURE LA English DT Editorial Material ID PULSAR 1E 2259+586; X-RAY; INFRARED OBSERVATIONS; COUNTERPART; SGR-1806-20 C1 [Kouveliotou, Chryssa] NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35805 USA. RP Kouveliotou, C (reprint author), NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35805 USA. EM chryssa.kouveliotou@nasa.gov NR 10 TC 1 Z9 1 U1 0 U2 2 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD SEP 25 PY 2008 VL 455 IS 7212 BP 477 EP 478 DI 10.1038/455477a PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 351TU UT WOS:000259449600032 PM 18818645 ER PT J AU Obirai, JC Hunter, G Dutta, PK AF Obirai, Joseph C. Hunter, Gary Dutta, Prabir K. TI Multi-walled carbon nanotubes as high temperature carbon monoxide sensors SO SENSORS AND ACTUATORS B-CHEMICAL LA English DT Article DE Combustion sensors; Harsh environment sensors; CO sensors ID ELECTRICAL BREAKDOWN; CHEMICAL SENSORS; SINGLE; FUNCTIONALIZATION; SENSITIVITY; ELECTRONICS; OXIDATION; DEFECTS AB Heat treatment of acid-treated multi-walled carbon nanotubes (MWCNTs) produces profound changes in their electrical properties. Below 600 degrees C the resistance of a thick film of MWCNT (similar to 100 mu m) was below 200 Q while at 700 degrees C, the resistance increased to over 20 M Omega. This process was irreversible. TEM showed that for a heat treatment <= 600 degrees C, the tube nature prevailed, but above 600 degrees C, nanoparticles of carbon materials with graphitic layers as well as tubes are present. The resistance changes upon interaction with carbon monoxide were monitored for materials heated at 600 and 700 degrees C. For materials heated at temperatures <= 600 degrees C, the largest changes in resistances (p-type) were observed at 400 degrees C with CO, with no measureable resistance changes at 100 and 600 degrees C. For materials heated to 700 degrees C, p-type resistance changes were observed for both CO and 02 between 600 and 700 degrees C, with no changes at 800 degrees C, and background resistances approaching 95 M Omega at 500 degrees C. MWCNTs are demonstrated as potential materials for carbon monoxide sensing over the temperature range of 600-700 degrees C, but not very suitable for sensing between 100 and 400 degrees C, primarily because of the drift in the background. (c) 2008 Elsevier B.V. All rights reserved. C1 [Obirai, Joseph C.; Dutta, Prabir K.] Ohio State Univ, Ctr Ind Sensors & Measurements, Dept Chem, Columbus, OH 43210 USA. [Hunter, Gary] NASA Glenn Res Ctr, Cleveland, OH 44135 USA. RP Dutta, PK (reprint author), Form Factor Inc, 7005 Southfront Rd, Livermore, CA 94551 USA. EM dutta.l@osu.edu FU NASA; DOE FX We acknowledge funding from NASA and DOE for this research NR 31 TC 7 Z9 8 U1 0 U2 9 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-4005 J9 SENSOR ACTUAT B-CHEM JI Sens. Actuator B-Chem. PD SEP 25 PY 2008 VL 134 IS 2 BP 640 EP 646 DI 10.1016/j.snb.2008.06.005 PG 7 WC Chemistry, Analytical; Electrochemistry; Instruments & Instrumentation SC Chemistry; Electrochemistry; Instruments & Instrumentation GA 361SJ UT WOS:000260147100048 ER PT J AU Dickey, JO Marcus, SL Willis, JK AF Dickey, J. O. Marcus, S. L. Willis, J. K. TI Ocean cooling: Constraints from changes in Earth's dynamic oblateness (J(2)) and altimetry SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID CLIMATE AB Dynamic oblateness (J(2)) observations reflect changes in the latitudinal distribution of mass within the Earth system, and hence can give insights into processes involving water transport and sea level rise. We seek to use records of J(2) variations deduced from satellite laser ranging, together with altimetry results, to provide an independent geodetic constraint on changes in ocean heat content (OHC). We show that the size and signature of the J(2) signal presented here do not support a recently published report of rapid oceanic heat loss beginning in 2003, which was subsequently attributed to Argo and other instrumental bias effects. Our results are consistent with recent findings of a flattening of the OHC trend at this time inferred from the bias-corrected Argo data, and demonstrate that J2 observations, in combination with other observational and model data types, can provide useful constraints for monitoring and validating ongoing changes in the Earth system. C1 [Dickey, J. O.; Marcus, S. L.; Willis, J. K.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Dickey, JO (reprint author), CALTECH, Jet Prop Lab, Mail Stop 238-600,4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM jean.o.dickey@jpl.nasa.gov OI Marcus, Steven/0000-0002-5763-6961 FU NASA FX We thank Chris Cox (Raytheon Integrated Defense Systems) for providing the SLR-based estimates of J2 variability, Chris Milly (USGS) for providing land hydrology data from the LaD model, and Ichiro Fukumori (JPL) for providing altimeter-assimilated ocean bottom pressure data from the ECCO model. Florian Seitz (Institut fuer Astronomische und Physikalische Geodaesie TU Munich) provided assistance with data processing and interpretation of the results. The comments of two anonymous reviewers helped to improve the manuscript. This research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with NASA. NR 14 TC 5 Z9 5 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 SEP 24 PY 2008 VL 35 IS 18 AR L18608 DI 10.1029/2008GL035115 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 353YN UT WOS:000259606200004 ER PT J AU Paillou, P Lunine, J Ruffie, G Encrenaz, P Wall, S Lorenz, R Janssen, M AF Paillou, Philippe Lunine, Jonathan Ruffie, Gilles Encrenaz, Pierre Wall, Stephen Lorenz, Ralph Janssen, Michael TI Microwave dielectric constant of Titan-relevant materials SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID CASSINI RADAR OBSERVATIONS; SURFACE; MAPPER; FREQUENCIES; ATMOSPHERE; DUNES; LAKES AB For four years, the Cassini Radar instrument has slowly revealed the surface of Titan. It has discovered cryovolcanic flows, craters, dunes, channels, rivers, lakes and seas. In order to analyze and model the microwave behaviour of Titan's surface, we need to know the dielectric constant of its surface materials. We present here Ku-band (10 and 13 GHz) measurements of the dielectric constant of various materials that are likely to be present on Titan. Most of the measured values are in the 1.5-4.3 range with a very low loss tangent (less than 10(-2)), consistent with results obtained from the Radar scatterometer and radiometer modes, indicating that the Cassini Ku-band Radar should penetrate several meters of Titan's surface. C1 [Paillou, Philippe] Univ Bordeaux, Lab Astrophys Bordeaux, UMR5804, F-33270 Floirac, France. [Encrenaz, Pierre] Observ Paris, Lab Etude Rayonnement & Matiere Astrophys, UMR8112, F-75014 Paris, France. [Wall, Stephen; Janssen, Michael] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Lorenz, Ralph] Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. [Lunine, Jonathan] Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. [Ruffie, Gilles] Univ Bordeaux, Lab Integrat Mat Syst, UMR5218, Pessac, France. RP Paillou, P (reprint author), Univ Bordeaux, Lab Astrophys Bordeaux, UMR5804, F-33270 Floirac, France. EM philippe.paillou@obs.u-bordeaux1.fr RI Lorenz, Ralph/B-8759-2016 OI Lorenz, Ralph/0000-0001-8528-4644 FU CNES FX The authors are grateful to CNES for financial support of this project and to C. Szopa and G. Cernogora from IPSL laboratory for providing tholins samples. They also thank an anonymous reviewer for his useful comments. Part of 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 38 TC 28 Z9 28 U1 1 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 SEP 24 PY 2008 VL 35 IS 18 AR L18202 DI 10.1029/2008GL035216 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 353YN UT WOS:000259606200005 ER PT J AU Terao, Y Logan, JA Douglass, AR Stolarski, RS AF Terao, Yukio Logan, Jennifer A. Douglass, Anne R. Stolarski, Richard S. TI Contribution of stratospheric ozone to the interannual variability of tropospheric ozone in the northern extratropics SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID VERTICAL-DISTRIBUTION; TRANSPORT MODEL; ART.; TRENDS; EXCHANGE; PACIFIC; CLIMATOLOGY AB We examined the role of variability in the input of stratospheric ozone on the interannual variability of tropospheric ozone in the northern extratropics using correlations of monthly ozone anomalies for the lower stratosphere and the troposphere. We used output from a multiyear simulation of the NASA Goddard Space Flight Center (GSFC) Chemistry and Transport Model (CTM), and evaluated model results using ozonesonde data. The GSFC CTM explicitly calculates stratospheric ozone and simulates separate tracers of stratospheric and tropospheric ozone (O-3-strat and O-3-trop, respectively). The climatological seasonal cycle of ozone shows that O-3-strat contributes significantly to the spring maximum of ozone at 500 hPa, similar to 40% at high latitudes and similar to 30% at midlatitudes. We find large regional differences in the correlation of ozone in the lower stratosphere and troposphere in the model that are supported by the ozonesonde data. Highest correlations are found from the eastern Atlantic to Europe, from the eastern Pacific to the western United States, and over the polar regions, in winter-spring. This spatial pattern is due to the input of O-3-strat into the troposphere. The distribution and time lag of the correlations (highest with no lag for midlatitudes and a 1-2 month lag for polar regions) are consistent with the dynamical indicators of stratosphere-troposphere exchange (STE), such as storm tracks in the midlatitudes and slow descending motion in the polar region. Our simple approach can be widely applied to diagnose the effect of STE on tropospheric ozone. C1 [Douglass, Anne R.; Stolarski, Richard S.] NASA, Goddard Space Flight Ctr, Atmospher Chem & Dynam Branch, Greenbelt, MD 20771 USA. [Logan, Jennifer A.] Harvard Univ, Sch Engn & Appl Sci, Cambridge, MA 02138 USA. RP Terao, Y (reprint author), Natl Inst Environm Studies, Ctr Global Environm Res, 16-2 Onogawa, Tsukuba, Ibaraki 3058506, Japan. EM yterao@nies.go.jp; jlogan@seas.harvard.edu RI Terao, Yukio/A-2099-2008; Douglass, Anne/D-4655-2012; Stolarski, Richard/B-8499-2013 OI Terao, Yukio/0000-0003-2345-7073; Stolarski, Richard/0000-0001-8722-4012 FU NASA/ACMAP FX The ozonesonde data were provided by WOUDC, Samuel Oltmans, and Francis Schmidlin. We would like to thank Inna A. Megretskaia for her assistance with the ozonesonde data. This work was supported by the NASA/ACMAP program. NR 35 TC 26 Z9 26 U1 3 U2 12 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 SEP 24 PY 2008 VL 113 IS D18 AR D18309 DI 10.1029/2008JD009854 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 353YT UT WOS:000259606800002 ER PT J AU Parrington, M Jones, DBA Bowman, KW Horowitz, LW Thompson, AM Tarasick, DW Witte, JC AF Parrington, M. Jones, D. B. A. Bowman, K. W. Horowitz, L. W. Thompson, A. M. Tarasick, D. W. Witte, J. C. TI Estimating the summertime tropospheric ozone distribution over North America through assimilation of observations from the Tropospheric Emission Spectrometer SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID TES NADIR RETRIEVALS; SATELLITE-OBSERVATIONS; STRATOSPHERIC OZONE; GLOBAL DISTRIBUTION; TRANSPORT MODELS; KALMAN FILTER; 3-D MODELS; CHEMISTRY; VARIABILITY; CONSTRAINTS AB We assimilate ozone and CO retrievals from the Tropospheric Emission Spectrometer (TES) for July and August 2006 into the GEOS-Chem and AM2-Chem models. We show that the spatiotemporal sampling of the TES measurements is sufficient to constrain the tropospheric ozone distribution in the models despite their different chemical and transport mechanisms. Assimilation of TES data reduces the mean differences in ozone between the models from almost 8 ppbv to 1.5 ppbv. Differences between the mean model profiles and ozonesonde data over North America are reduced from almost 30% to within 5% for GEOS-Chem, and from 40% to within 10% for AM2-Chem, below 200 hPa. The absolute biases are larger in the upper troposphere and lower stratosphere (UT/LS), increasing to 10% and 30% in GEOS-Chem and AM2-Chem, respectively, at 200 hPa. The larger bias in the UT/LS reflects the influence of the spatial sampling of TES, the vertical smoothing of the TES retrievals, and the coarse vertical resolution of the models. The largest discrepancy in ozone between the models is associated with the ozone maximum over the southeastern USA. The assimilation reduces the mean bias between the models from 26 to 16 ppbv in this region. In GEOS-Chem, there is an increase of about 11 ppbv in the upper troposphere, consistent with the increase in ozone obtained by a previous study using GEOS-Chem with an improved estimate of lightning NOx emissions over the USA. Our results show that assimilation of TES observations into models of tropospheric chemistry and transport provides an improved description of free tropospheric ozone. C1 [Parrington, M.; Jones, D. B. A.] Univ Toronto, Dept Phys, Toronto, ON M5S 1A7, Canada. [Horowitz, L. W.] Geophys Fluid Dynam Lab, NOAA, Princeton, NJ 08540 USA. [Bowman, K. W.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Tarasick, D. W.] Environm Canada, Air Qual Res Div, Meteorol Serv Ctr, Downsview, ON M3H 5T4, Canada. [Thompson, A. M.] Penn State Univ, Dept Meteorol, University Pk, PA 16802 USA. [Witte, J. C.] Sci Syst & Applicat Inc, Lanham, MD 20706 USA. [Witte, J. C.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Parrington, M (reprint author), Univ Toronto, Dept Phys, 60 St George St, Toronto, ON M5S 1A7, Canada. EM mark.parrington@utoronto.ca RI Parrington, Mark/E-7148-2013; Horowitz, Larry/D-8048-2014; Jones, Dylan/O-2475-2014; Chem, GEOS/C-5595-2014; Thompson, Anne /C-3649-2014; OI Parrington, Mark/0000-0003-4313-6218; Horowitz, Larry/0000-0002-5886-3314; Jones, Dylan/0000-0002-1935-3725; Thompson, Anne /0000-0002-7829-0920; Tarasick, David/0000-0001-9869-0692 FU Canadian Foundation for Climate and Atmospheric Sciences (CFCAS); Natural Sciences and Engineering Research Council (NSERC) FX This work was supported by funding from the Canadian Foundation for Climate and Atmospheric Sciences (CFCAS) and the Natural Sciences and Engineering Research Council (NSERC). The GEOS-Chem model is maintained at Harvard University with support from the NASA Atmospheric Chemistry Modeling and Analysis Program. NR 59 TC 43 Z9 43 U1 1 U2 13 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 SEP 23 PY 2008 VL 113 IS D18 AR D18307 DI 10.1029/2007JD009341 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 353YS UT WOS:000259606700002 ER PT J AU Fisher, D Novak, R Mumma, MJ AF Fisher, David Novak, Robert Mumma, Michael J. TI D/H ratio during the northern polar summer and what the Phoenix mission might measure SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID MARTIAN ATMOSPHERE; WATER CYCLE; MARS; EVOLUTION; REGOLITH; ISOTOPES; VAPOR; ICE; CAP AB The Phoenix polar mission will land close to 68 degrees N, 233 degrees E in May 2008 at Ls similar to 75 and operate 90 sols until Ls similar to 125 with possible extension to Ls similar to 142. Phoenix Meteorology (MET), Thermal and Evolved Gas Analyzer (TEGA) and Microscopy, Electrochemistry and Conductivity Analyzer (MECA) instrument packages will measure the air's temperature, water vapor concentration, ice crystal concentration and the water's stable isotope ratio D/H, and the D/H for the uppermost ground ice. This paper summarizes what is known about the seasonal cycle of atmospheric D/H and makes a theoretical connection between the atmospheric ratio and that expected from the ground ice that Phoenix will sample. A simple mixed cloud stable isotope model is used to show that the seasonal progress of D/H in the polar region cannot be used alone. It is argued that the seasonal cycle in D/H is explained by their being an interplay between multilatitudinal sources or reservoirs that have a range of reservoir D/H values. These reservoirs have different sizes and seasonal response times so that they release their water contributions at different times of the spring and summer and together explain most of the seasonal D/H observed by Mumma et al. (2003) and Novak et al. (2005). Phoenix observations from its high-latitude vantage point during the summer and fall will add some atmospheric D/H values, temperature, water vapor concentration, and ice cloudiness data points that will constrain the various theoretical possibilities. The D/H of the ice recovered by Phoenix from the surface of the ground ice combined with the atmospheric D/H will suggest, whether the ground ice presently is a net receiver or supplier of water to the northern ice cap. C1 [Fisher, David] Geol Survey Canada, Glaciol Sect, NRCan, Ottawa, ON K1A 0E8, Canada. [Mumma, Michael J.] NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. [Novak, Robert] Iona Coll, Dept Phys, New Rochelle, NY 10801 USA. RP Fisher, D (reprint author), Geol Survey Canada, Glaciol Sect, NRCan, 601 Booth St, Ottawa, ON K1A 0E8, Canada. EM david.fisher@nrcan.gc.ca; rnovak@iona.edu; mmumma@lepvax.gsfc.nasa.gov RI mumma, michael/I-2764-2013 NR 29 TC 10 Z9 10 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 SEP 23 PY 2008 VL 113 AR E00A15 DI 10.1029/2007JE002972 PG 7 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 353ZB UT WOS:000259607600001 ER PT J AU Kliore, AJ Nagy, AF Marouf, EA French, RG Flasar, FM Rappaport, NJ Anabttawi, A Asmar, SW Kahann, DS Barbinis, E Goltz, GL Fleischman, DU Rochblatt, DJ AF Kliore, Avydas J. Nagy, Andrew F. Marouf, Essam A. French, Richard G. Flasar, F. Michael Rappaport, Nicole J. Anabttawi, Aseel Asmar, Sami W. Kahann, Daniel S. Barbinis, Elias Goltz, Gene L. Fleischman, Don U. Rochblatt, David J. TI First results from the Cassini radio occultations of the Titan ionosphere SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID PLASMA; MODEL; MAGNETOSPHERE; ATMOSPHERE; SPECTROMETER; IONIZATION; CHEMISTRY; DYNAMICS AB The first four sets of radio occultations of the Titan's ionosphere were obtained by the Cassini spacecraft between March 2006 and May 2007. These occultations occurred at middle and high latitudes, at solar zenith angles from about 86 degrees to 96 degrees. The main ionospheric peak was seen, as expected from modeling and previous observations, near 1200 km, with a density of about 1-3 x 10(3) cm(-3). A consistent ledge near 1000 km was also seen, and one of the polar observations found a significant (similar to 3 x 10(3) cm(-3)) layer in the region of 500-600 km. This layer also is seen in other observations with a density varying from about 0.7 to 1.7 x 10(3) cm(-3), suggesting a variable production source (or sources) for this peak. C1 [Kliore, Avydas J.; Rappaport, Nicole J.; Anabttawi, Aseel; Asmar, Sami W.; Kahann, Daniel S.; Barbinis, Elias; Goltz, Gene L.; Fleischman, Don U.; Rochblatt, David J.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Flasar, F. Michael] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [French, Richard G.] Wellesley Coll, Dept Astron, Wellesley, MA 02481 USA. [Marouf, Essam A.] San Jose State Univ, Dept Elect Engn, San Jose, CA 95192 USA. [Nagy, Andrew F.] Univ Michigan, Space Phys Res Lab, Ann Arbor, MI 48109 USA. RP Kliore, AJ (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM akliore@jpl.nasa.gov RI Flasar, F Michael/C-8509-2012 FU Cassini Program; NASA [NAG5-13332] FX The work described in this paper was supported by the Cassini Program at JPL. One of the authors, AFN, was also partially supported in this work by NASA grant NAG5-13332. The authors wish to express their gratitude to the personnel of the Deep Space Net (DSN), who were instrumental in the successful acquisition of their data.; Zuyin Pu thanks Jan-Erik Wahlund and Jack Waite for their assistance in evaluating this paper. NR 30 TC 49 Z9 49 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 SEP 23 PY 2008 VL 113 IS A9 AR A09317 DI 10.1029/2007JA012965 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 353ZK UT WOS:000259608500001 ER PT J AU Sun, GY Palazzolo, A Provenza, A Lawrence, C Carney, K AF Sun, Guangyoung Palazzolo, Alan Provenza, A. Lawrence, C. Carney, K. TI Long duration blade loss simulations including thermal growths for dual-rotor gas turbine engine SO JOURNAL OF SOUND AND VIBRATION LA English DT Article ID CHAMBERED POROUS DAMPER; VIBRATION CONTROL; SYSTEMS; DYNAMICS AB This paper presents an approach for blade loss simulation including thermal growth effects for a dual-rotor gas turbine engine supported on bearing and squeeze film damper. A nonlinear ball bearing model using the Hertzian formula predicts ball contact load and stress, while a simple thermal model estimates the thermal growths of bearing components during the blade loss event. The modal truncation augmentation method combined with a proposed staggered integration scheme is verified through simulation results as an efficient tool for analyzing a flexible dual-rotor gas turbine engine dynamics with the localized nonlinearities of the bearing and damper, with the thermal growths and with a flexible casing model. The new integration scheme with enhanced modeling capability reduces the computation time by a factor of 12, while providing a variety of solutions with acceptable accuracy for durations extending over several thermal time constants. (C) 2008 Elsevier Ltd. All rights reserved. C1 [Sun, Guangyoung] NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. [Palazzolo, Alan] Texas A&M Univ, College Stn, TX 77840 USA. [Provenza, A.; Lawrence, C.; Carney, K.] NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Sun, GY (reprint author), NASA, Glenn Res Ctr, 21000 Brookpk Rd,MS 301-5, Cleveland, OH 44135 USA. EM dr.gysun@gmail.com; a-palazzolo@neo.tamu.edu NR 19 TC 11 Z9 21 U1 2 U2 10 PU ACADEMIC PRESS LTD ELSEVIER SCIENCE LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0022-460X J9 J SOUND VIB JI J. Sound Vibr. PD SEP 23 PY 2008 VL 316 IS 1-5 BP 147 EP 163 DI 10.1016/j.jsv.2008.02.045 PG 17 WC Acoustics; Engineering, Mechanical; Mechanics SC Acoustics; Engineering; Mechanics GA 324KK UT WOS:000257517300010 ER PT J AU Babak, S Baker, JG Benacquista, MJ Cornish, NJ Crowder, J Larson, SL Plagnol, E Porter, EK Vallisneri, M Vecchio, A Arnaud, K Barack, L Blaut, A Cutler, C Fairhurst, S Gair, J Gong, XF Harry, I Khurana, D Krolak, A Mandel, I Prix, R Sathyaprakash, BS Savov, P Shang, Y Trias, M Veitch, J Wang, Y Wen, LQ Whelan, JT AF Babak, Stanislav Baker, John G. Benacquista, Matthew J. Cornish, Neil J. Crowder, Jeff Larson, Shane L. Plagnol, Eric Porter, Edward K. Vallisneri, Michele Vecchio, Alberto Arnaud, Keith Barack, Leor Blaut, Arkadiusz Cutler, Curt Fairhurst, Stephen Gair, Jonathan Gong, Xuefei Harry, Ian Khurana, Deepak Krolak, Andrzej Mandel, Ilya Prix, Reinhard Sathyaprakash, B. S. Savov, Pavlin Shang, Yu Trias, Miquel Veitch, John Wang, Yan Wen, Linqing Whelan, John T. CA Mock LISA Data Challenge Task Forc Challenge 1B Participants TI The Mock LISA Data Challenges: from Challenge 1B to Challenge 3 SO CLASSICAL AND QUANTUM GRAVITY LA English DT Article; Proceedings Paper CT 12th Gravitational Wave Data Analysis Workshop CY DEC 13-16, 2007 CL Cambridge, MA SP MIT, LIGO Lab ID POPULATION; BINARIES AB The Mock LISA Data Challenges are a programme to demonstrate and encourage the development of LISA data-analysis capabilities, tools and techniques. At the time of this workshop, three rounds of challenges had been completed, and the next was about to start. In this paper we provide a critical analysis of the entries to the latest completed round, Challenge 1B. The entries confirm the consolidation of a range of data-analysis techniques for galactic and massive-black-hole binaries, and they include the first convincing examples of detection and parameter estimation of extreme-mass-ratio inspiral sources. In this paper we also introduce the next round, Challenge 3. Its data sets feature more realistic waveform models (e. g., galactic binaries may now chirp, and massive-black-hole binaries may precess due to spin interactions), as well as new source classes (bursts from cosmic strings, isotropic stochastic backgrounds) and more complicated nonsymmetric instrument noise. C1 [Babak, Stanislav; Porter, Edward K.; Gair, Jonathan; Wen, Linqing; Whelan, John T.] Max Planck Inst Gravitat Phys Albert Einstein Ins, D-14476 Golm, Germany. [Benacquista, Matthew J.] Univ Texas Brownsville, Ctr Gravitat Wave Astron, Brownsville, TX 78520 USA. [Baker, John G.; Arnaud, Keith] NASA, Goddard Space Flight Ctr, Gravitat Astrophys Lab, Greenbelt, MD 20771 USA. [Cornish, Neil J.] Montana State Univ, Dept Phys, Bozeman, MT 59717 USA. [Crowder, Jeff; Vallisneri, Michele; Cutler, Curt] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Larson, Shane L.] Weber State Univ, Dept Phys, Ogden, UT 84408 USA. [Plagnol, Eric] Univ Paris 07, APC, UMR 7164, F-75025 Paris 13, France. [Vallisneri, Michele; Cutler, Curt; Mandel, Ilya; Savov, Pavlin; Wen, Linqing] CALTECH, Pasadena, CA 91125 USA. [Vecchio, Alberto; Veitch, John] Univ Birmingham, Sch Phys & Astron, Birmingham B15 2TT, W Midlands, England. [Barack, Leor] Univ Southampton, Sch Math, Southampton SO17 1BJ, Hants, England. [Blaut, Arkadiusz] Univ Wroclaw, Inst Theoret Phys, PL-50138 Wroclaw, Poland. [Fairhurst, Stephen; Harry, Ian; Sathyaprakash, B. S.] Cardiff Univ, Sch Phys & Astron, Cardiff CF24 3YB, S Glam, Wales. [Gair, Jonathan] Univ Cambridge, Inst Astron, Cambridge CB3 0HA, England. [Gong, Xuefei] Chinese Acad Sci, Inst Appl Math, Acad Math & Syst Sci, Beijing 100080, Peoples R China. [Khurana, Deepak; Shang, Yu] Indian Inst Technol, Kharagpur 721302, W Bengal, India. [Krolak, Andrzej] Polish Acad Sci, Inst Math, Warsaw, Poland. [Prix, Reinhard] Max Planck Inst Gravitat Phys Albert Einstein Ins, D-30167 Hannover, Germany. [Mandel, Ilya] Northwestern Univ, Dept Phys & Astron, Evanston, IL USA. [Trias, Miquel] Univ Illes Balears, Dept Fis, E-07122 Palma de Mallorca, Spain. [Wang, Yan] Nanjing Univ, Dept Astron, Nanjing 210093, Peoples R China. [Wen, Linqing] Univ Western Australia, Sch Phys, Crawley, WA 6009, Australia. RP Babak, S (reprint author), Max Planck Inst Gravitat Phys Albert Einstein Ins, Am Muehlenberg 1, D-14476 Golm, Germany. EM Michele.Vallisneri@jpl.nasa.gov RI Larson, Shane/E-8576-2010; Vecchio, Alberto/F-8310-2015; OI Vecchio, Alberto/0000-0002-6254-1617; Whelan, John/0000-0001-5710-6576; Fairhurst, Stephen/0000-0001-8480-1961; Mandel, Ilya/0000-0002-6134-8946; Veitch, John/0000-0002-6508-0713 NR 41 TC 37 Z9 37 U1 0 U2 5 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0264-9381 EI 1361-6382 J9 CLASSICAL QUANT GRAV JI Class. Quantum Gravity PD SEP 21 PY 2008 VL 25 IS 18 AR 184026 DI 10.1088/0264-9381/25/18/184026 PG 20 WC Astronomy & Astrophysics; Physics, Multidisciplinary; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 344HE UT WOS:000258916700027 ER PT J AU Gehrels, N AF Gehrels, Neil CA Swift Team TI Gamma-ray burst overview SO CLASSICAL AND QUANTUM GRAVITY LA English DT Article; Proceedings Paper CT 12th Gravitational Wave Data Analysis Workshop CY DEC 13-16, 2007 CL Cambridge, MA SP MIT, LIGO Lab ID 28 FEBRUARY 1997; REDSHIFT DISTRIBUTION; HOST GALAXY; AFTERGLOW; PROGENITORS; GRB-050709; TELESCOPE; SUPERNOVA; EMISSION; ORIGIN AB Since its launch on 20 November 2004, the Swift mission has detected similar to 100 gamma-ray bursts (GRBs) each year, and immediately (within similar to 90 s) started x-ray and UV/optical observations of the afterglow. It has already collected an impressive database including prompt emission to higher sensitivities than BATSE, uniform monitoring of afterglows and rapid follow-up by other observatories notified through the GCN. The x-ray afterglows have been found to have complex temporal shapes including tail emission from the prompt phase and bright flares. X-ray and optical afterglow detections from short bursts have led to accurate localizations. It is found that short bursts can occur in non-star forming galaxies or regions, whereas long GRBs are strongly concentrated within star forming regions. The location of short bursts in regions of galaxies where late-type stars reside is consistent with the NS merger model. Concerning the connection of GRBs to supernovae, GRB 060218 associated with SN 2006aj adds a valuable member to the class of GRBs with detected supernova. The prospects for future progress are excellent given the > 10 years orbital lifetime of the Swift satellite. C1 [Gehrels, Neil; Swift Team] NASA, Goddard Space Flight Ctr, Astroparticle Phys Div, Greenbelt, MD 20771 USA. RP Gehrels, N (reprint author), NASA, Goddard Space Flight Ctr, Astroparticle Phys Div, Greenbelt, MD 20771 USA. EM neil.gehrels@nasa.gov RI Gehrels, Neil/D-2971-2012 NR 53 TC 0 Z9 0 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0264-9381 J9 CLASSICAL QUANT GRAV JI Class. Quantum Gravity PD SEP 21 PY 2008 VL 25 IS 18 AR 184005 DI 10.1088/0264-9381/25/18/184005 PG 7 WC Astronomy & Astrophysics; Physics, Multidisciplinary; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 344HE UT WOS:000258916700006 ER PT J AU Maschietto, F Hatch, NA Venemans, BP Rottgering, HJA Miley, GK Overzier, RA Dopita, MA Eisenhardt, PR Kurk, JD Meurer, GR Pentericci, L Rosati, P Stanford, SA van Breugel, W Zirm, AW AF Maschietto, F. Hatch, N. A. Venemans, B. P. Roettgering, H. J. A. Miley, G. K. Overzier, R. A. Dopita, M. A. Eisenhardt, P. R. Kurk, J. D. Meurer, G. R. Pentericci, L. Rosati, P. Stanford, S. A. van Breugel, W. Zirm, A. W. TI [O III] emitters in the field of the MRC 0316-257 protocluster SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE galaxies : active; galaxies : clusters : general; galaxies : evolution; cosmology : observations; early Universe ID LYMAN-BREAK GALAXIES; LARGE-SCALE STRUCTURE; STAR-FORMING GALAXIES; LY-ALPHA EMITTERS; REST-FRAME ULTRAVIOLET; RADIO GALAXY; HIGH-REDSHIFT; INFRARED OBSERVATIONS; FORMATION HISTORY; SPIDERWEB GALAXY AB Venemans et al. found evidence for an overdensity of Ly alpha emission-line galaxies associated with the radio galaxy MRC 0316-257 at z = 3.13 indicating the presence of a massive protocluster. Here, we present the results of a search for additional star-forming galaxies and active galactic nucleus (AGN) within the protocluster. Narrow-band infrared imaging was used to select candidate [O III] emitters in a 1.1 x 1.1 Mpc(2) region around the radio galaxy. 13 candidates have been detected. Four of these are among the previously confirmed sample of Ly alpha galaxies, and an additional three have been confirmed through follow-up infrared spectroscopy. The three newly confirmed objects lie within a few hundred km s(-1) of each other, but are blueshifted with respect to the radio galaxy and Ly alpha emitters by similar to 2100 km s(-1). Although the sample is currently small, our results indicate that the radio-selected protocluster is forming at the centre of a larger, similar to 60 comoving Mpc superstructure. On the basis of a Hubble Space Telescope/Advanced Camera for Surveys (HST/ACS) imaging study we calculate dust-corrected star formation rates and investigate morphologies and sizes of the [O III] candidate emitters. From a comparison of the star formation rate derived from UV continuum and [O III] emission, we conclude that at least two of the [O III] galaxies harbour an AGN which ionized the O(+) gas. C1 [Maschietto, F.; Hatch, N. A.; Roettgering, H. J. A.; Miley, G. K.; Zirm, A. W.] Leiden Univ, Leiden Observ, NL-2333 CA Leiden, Netherlands. [Venemans, B. P.] Inst Astron, Cambridge CB3 OAH, England. [Overzier, R. A.] Max Planck Inst Astrophys, D-85741 Garching, Germany. [Dopita, M. A.] Australian Natl Univ, Res Sch Astron & Astrophys, Weston, ACT 2611, Australia. [Eisenhardt, P. R.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Kurk, J. D.] Max Planck Inst Astron, D-69117 Heidelberg, Germany. [Meurer, G. R.; Zirm, A. W.] Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. [Pentericci, L.] INAF Osservatorio Astron Roma, I-00040 Monte Porzio Catone, Italy. [Rosati, P.] European So Observ, D-85748 Garching, Germany. [Stanford, S. A.] Univ Calif Davis, Davis, CA 95616 USA. [Stanford, S. A.; van Breugel, W.] Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Livermore, CA 94551 USA. [van Breugel, W.] Univ Calif, Merced, CA 95344 USA. RP Maschietto, F (reprint author), Leiden Univ, Leiden Observ, Niels Bohrweg 2, NL-2333 CA Leiden, Netherlands. EM maschietto@strw.leidenuniv.nl RI Dopita, Michael/P-5413-2014; OI Dopita, Michael/0000-0003-0922-4986; Hatch, Nina/0000-0001-5600-0534 FU Royal Netherlands Academy of Arts and Sciences FX This research is based on observations made with the VLT at ESO, Paranal, with program numbers 077.A-0310(A, B) and 078. A-0002( A, B), and on observations made with the NASA/ESA HST, obtained from the data archive at the Space Telescope Science Institute (STScI). STScI is operated by the Association of Universities for Research in Astronomy, Inc. under NASA contract NAS 5-26555. NAH and GKM acknowledge funding from the Royal Netherlands Academy of Arts and Sciences. NR 63 TC 13 Z9 13 U1 0 U2 2 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD SEP 21 PY 2008 VL 389 IS 3 BP 1223 EP 1232 DI 10.1111/j.1365-2966.2008.13571.x PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 346RS UT WOS:000259087500018 ER PT J AU Malizia, A Bassani, L Bird, AJ Landi, R Masetti, N De Rosa, A Panessa, F Molina, M Dean, AJ Perri, M Tueller, J AF Malizia, A. Bassani, L. Bird, A. J. Landi, R. Masetti, N. De Rosa, A. Panessa, F. Molina, M. Dean, A. J. Perri, M. Tueller, J. TI First high-energy observations of narrow-line Seyfert 1s with INTEGRAL/IBIS SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE galaxies : active; galaxies : Seyfert; X-rays : galaxies ID ACTIVE GALACTIC NUCLEI; BEPPOSAX OBSERVATIONS; OPTICAL SPECTROSCOPY; BLACK-HOLES; GALAXIES; EMISSION; SPECTRA; OBJECTS; AGN; IDENTIFICATION AB Narrow-line Seyfert 1 (NLS1) galaxies are very interesting objects which display peculiar properties when compared to their broad-line analogues (BLS1). Although well studied in many wavebands, their behaviour at > 10 keV is poorly studied and yet important to discriminate between models invoked to explain the complexity observed in the X-ray band. Here, we present for the first time high-energy observations (17-100 keV) of five NLS1 galaxies (three bona fide and two candidates) detected by INTEGRAL/Imager on Board INTEGRAL Satellite (IBIS) and provide for all of them a broad-band spectral analysis using data obtained by Swift/XRT below 10 keV. The combined INTEGRAL spectrum is found to be steeper (Gamma = 2.6 +/- 0.3) than those of classical Seyfert 1 objects. This is due to a high-energy cut-off, which is required in some individual fits as in the average broad-band spectrum. The location of this high-energy cut-off is at lower energies (E <= 60 keV) than typically seen in classical type 1 active galactic nuclei (AGNs); a reflection component may also be present but its value (R < 0.8) is compatible with those seen in standard Seyfert 1s. We do not detect a soft excess in individual objects but only in their cumulative spectrum. Our results suggest a lower plasma temperature for the accreting plasma which combined to the high accretion rates (close to the Eddington rate) points to different nuclear conditions in broad and NLS1 galaxies, likely related to different evolutionary stages. C1 [Malizia, A.; Bassani, L.; Landi, R.; Masetti, N.] IASF INAF, I-40129 Bologna, Italy. [Bird, A. J.; Molina, M.; Dean, A. J.] Univ Southampton, Sch Phys & Astron, Southampton SO17 1BJ, Hants, England. [De Rosa, A.; Panessa, F.] IASF INAF, I-00133 Rome, Italy. [Perri, M.] ESRIN, ASDC, ASI Sci Data Ctr, I-00044 Frascati, Italy. [Tueller, J.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Malizia, A (reprint author), IASF INAF, Via Gobetti 101, I-40129 Bologna, Italy. EM malizia@iasfbo.inaf.it RI Tueller, Jack/D-5334-2012; OI Malizia, Angela/0000-0002-6558-1163; Bassani, Loredana/0000-0003-4858-6963; Perri, Matteo/0000-0003-3613-4409; De Rosa, Alessandra/0000-0001-5668-6863; Masetti, Nicola/0000-0001-9487-7740; Panessa, Francesca/0000-0003-0543-3617 FU ASI [I/008/07/0, I/088/06/0] FX We acknowledge ASI financial and programmatic support via contracts I/008/07/0 and I/088/06/0. Optical data used are partially based on observations performed with Loiano Astronomical Observatory (Bologna, Italy). We thank Antonio De Blasi for the night assistance at the telescope. NR 47 TC 32 Z9 32 U1 0 U2 0 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 SEP 21 PY 2008 VL 389 IS 3 BP 1360 EP 1366 DI 10.1111/j.1365-2966.2008.13657.x PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 346RS UT WOS:000259087500033 ER PT J AU Wise, JH Abel, T AF Wise, John H. Abel, Tom TI Resolving the formation of protogalaxies. III. Feedback from the first stars SO ASTROPHYSICAL JOURNAL LA English DT Review DE cosmology : theory; galaxies : dwarf; galaxies : high-redshift; stars : formation ID PROBE WMAP OBSERVATIONS; PRIMORDIAL HII-REGIONS; VERY-LOW METALLICITY; LY-ALPHA EMITTERS; METAL-POOR STARS; POPULATION-III; RADIATIVE FEEDBACK; GALAXY FORMATION; SUPERNOVA EXPLOSIONS; DWARF GALAXIES AB The first stars form in dark matter halos of masses similar to 10(6) M(circle dot) as suggested by an increasing number of numerical simulations. Radiation feedback from these stars expels most of the gas from the shallow potential well of their surrounding dark matter halos. We use cosmological adaptive mesh refinement simulations that include self-consistent Population III star formation and feedback to examine the properties of assembling early dwarf galaxies. Accurate radiative transport is modeled with adaptive ray tracing. We include supernova explosions and follow the metal enrichment of the intergalactic medium. The calculations focus on the formation of several dwarf galaxies and their progenitors. In these halos, baryon fractions in 10(8) M(circle dot) halos decrease by a factor of 2 with stellar feedback and by a factor of 3 with supernova explosions. We find that radiation feedback and supernova explosions increase gaseous spin parameters up to a factor of 4 and vary with time. Stellar feedback, supernova explosions, and H(2) cooling create a complex, multiphase interstellar medium whose densities and temperatures can span up to 6 orders of magnitude at a given radius. The pair-instability supernovae of Population III stars alone enrich the halos with virial temperatures of 10(4) K to approximately 10(-3) of solar metallicity. We find that 40% of the heavy elements resides in the intergalactic medium (IGM) at the end of our calculations. The highest metallicity gas exists in supernova remnants and very dilute regions of the IGM. C1 [Wise, John H.; Abel, Tom] Stanford Univ, Kavli Inst Particle Astrophys & Cosmol, Menlo Pk, CA 94025 USA. [Wise, John H.] NASA, Goddard Space Flight Ctr, Lab Observat Cosmol, Greenbelt, MD 21114 USA. RP Wise, JH (reprint author), Stanford Univ, Kavli Inst Particle Astrophys & Cosmol, Menlo Pk, CA 94025 USA. EM john.h.wise@nasa.gov FU National Science Foundation [AST-0239709, PHY05-51164] FX This work was supported by NSF CAREER award AST-0239709 from the National Science Foundation and partially supported by the National Science Foundation under grant PHY05-51164. We thank Marcelo Alvarez, Greg Bryan, and Naoki Yoshida for providing constructive comments on an early draft. Comments from an anonymous referee enhanced this paper by suggesting that we explore the importance of metal cooling, self-shielding, and metal mixing. We are grateful for the continuous support from the computational team at SLAC. We benefited from the hospitality of KITP at UC Santa Barbara, where this work was completed. We performed these calculations on 16 processors of a SGI Altix 3700 Bx2 at KIPAC at Stanford University. NR 114 TC 150 Z9 150 U1 0 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 SEP 20 PY 2008 VL 685 IS 1 BP 40 EP 56 DI 10.1086/590417 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 349WO UT WOS:000259314200004 ER PT J AU Frieswijk, WF Spaans, M Shipman, RF Teyssier, D Carey, SJ Tielens, AGGM AF Frieswijk, W. F. Spaans, M. Shipman, R. F. Teyssier, D. Carey, S. J. Tielens, A. G. G. M. TI SPITZER'S MID-INFRARED VIEW ON AN OUTER-GALAXY INFRARED DARK CLOUD CANDIDATE TOWARD NGC 7538 SO ASTROPHYSICAL JOURNAL LETTERS LA English DT Article DE dust, extinction; infrared: ISM; ISM: clouds; stars: formation ID STAR-FORMATION; COLD CORES AB Infrared dark clouds (IRDCs) represent the earliest observed stages of clustered star formation, characterized by large column densities of cold and dense molecular material observed in silhouette against a bright background of mid-IR emission. Up to now, IRDCs were predominantly known toward the inner Galaxy where background infrared emission levels are high. We present Spitzer observations with the Infrared Array Camera toward object G111.80+0.58 (G111) in the outer Galactic plane, located at a distance of similar to 3 kpc from us and similar to 10 kpc from the Galactic center. Earlier results show that G111 is a massive, cold molecular clump very similar to IRDCs. The mid-IR Spitzer observations unambiguously detect object G111 in absorption. We have identified for the first time an IRDC in the outer Galaxy, which confirms the suggestion that cluster-forming clumps are present throughout the Galactic plane. However, against a low mid-IR background such as the outer Galaxy it takes some effort to find them. C1 [Frieswijk, W. F.; Spaans, M.] Univ Groningen, Kapteyn Astron Inst, NL-9700 AV Groningen, Netherlands. [Frieswijk, W. F.; Shipman, R. F.] Univ Groningen, Natl Inst Space Res, NL-9700 AV Groningen, Netherlands. [Teyssier, D.] ESAC, Madrid 28080, Spain. [Carey, S. J.] CALTECH, Spitzer Sci Ctr, Pasadena, CA 91125 USA. [Tielens, A. G. G. M.] NASA, Ames Res Ctr, Moffett Field, CA USA. RP Frieswijk, WF (reprint author), Univ Groningen, Kapteyn Astron Inst, POB 800, NL-9700 AV Groningen, Netherlands. EM frieswyk@astro.rug.nl; spaans@astro.rug.nl; R.F.Shipman@sron.nl; David.Teyssier@sciops.esa.int; carey@ipac.caltech.edu; Alexander.G.Tielens@nasa.gov NR 25 TC 5 Z9 5 U1 1 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 SEP 20 PY 2008 VL 685 IS 1 BP L51 EP L54 DI 10.1086/592382 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 398KK UT WOS:000262730800013 ER PT J AU Frye, BL Bowen, DV Hurley, M Tripp, TM Fan, XH Holden, B Guhathakurta, P Coe, D Broadhurst, T Egami, E Meylan, G AF Frye, Brenda L. Bowen, David V. Hurley, Mairead Tripp, Todd M. Fan, Xiaohui Holden, Bradford Guhathakurta, Puragra Coe, Dan Broadhurst, Tom Egami, Eiichi Meylan, G. TI OBSERVATIONS OF THE GAS RESERVOIR AROUND A STAR-FORMING GALAXY IN THE EARLY UNIVERSE SO ASTROPHYSICAL JOURNAL LETTERS LA English DT Article DE galaxies: clusters: general; galaxies: clusters: individual (A1689); galaxies: high-redshift; gravitational lensing; methods: data analysis; techniques: spectroscopic ID GAMMA-RAY BURST; NEUTRAL HYDROGEN; EVOLUTION; REDSHIFT; Z-SIMILAR-TO-6; REIONIZATION; ABSORPTION; OUTFLOWS; QUASARS AB We present a high signal-to-noise spectrum of a bright galaxy at z = 4.9 in 14 hr of integration on VLT FORS2. This galaxy is extremely bright, i(850) = 23.10 +/- 0.01, and is strongly lensed by the foreground massive galaxy cluster A1689 (z = 0.18). Stellar continuum is seen longward of the Ly alpha emission line at similar to 7100 angstrom, while intergalactic H I produces strong absorption shortward of Ly alpha. Two transmission spikes at similar to 6800 and similar to 7040 are also visible, along with other structures at shorter wavelengths. Although this star-forming is galaxy fainter angstrom than a QSO, the absence of a strong central ultraviolet flux source in it enables a measurement of the H I flux transmission in the intergalactic medium (IGM) in the vicinity of a high-redshift object. We find that the effective H I optical depth of the IGM is remarkably high within a large 14 Mpc (physical) region surrounding the galaxy compared to that seen toward QSOs at similar redshifts. Evidently, this high-redshift galaxy is located in a region of space where the amount of H I is much larger than that seen at similar epochs in the diffuse IGM. We argue that observations of high-redshift galaxies like this one provide unique insights into the nascent stages of baryonic large-scale structures that evolve into the filamentary cosmic web of galaxies and clusters of galaxies observed in the current universe. C1 [Frye, Brenda L.; Hurley, Mairead] Dublin City Univ, Sch Phys Sci, Dublin 9, Ireland. [Bowen, David V.] Princeton Univ, Dept Astrophys Sci, Princeton, NJ 08540 USA. [Tripp, Todd M.] Univ Massachusetts, Dept Astron, Amherst, MA 01003 USA. [Fan, Xiaohui; Egami, Eiichi] Univ Arizona, Dept Astron, Tucson, AZ 85721 USA. [Fan, Xiaohui; Egami, Eiichi] Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. [Holden, Bradford; Guhathakurta, Puragra] Univ Calif Santa Cruz, Lick Observ, UCO, Santa Cruz, CA 95064 USA. [Coe, Dan] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Broadhurst, Tom] Tel Aviv Univ, Sch Phys & Astron, IL-69988 Ramat Aviv, Israel. [Meylan, G.] Ecole Polytech Fed Lausanne Observ, Astrophys Lab, CH-1290 Sauverny, Switzerland. RP Frye, BL (reprint author), Dublin City Univ, Sch Phys Sci, Dublin 9, Ireland. FU NASA [NAS5-32865, NNG05GE26G]; Science Foundation Ireland Research Frontiers Programme [PHY008] FX This work is based on data from the HST ACS instrument, which was developed under NASA contract NAS5-32865, and on the Very Large Telescope FORS2 instrument. B. L. F. is supported by Science Foundation Ireland Research Frontiers Programme grant PHY008. D. V. B. is funded through NASA Long-Term Space Astrophysics grant NNG05GE26G. The work of D. A. C. was carried out at Jet Propulsion Laboratory, California Institute of Technology, under a contract with NASA. We thank Holland Ford, Garth Illingworth, Avi Loeb, Rogier Windhorst, and Sergey Cherkis for discussions and Rychard Bouwens for the HST NICMOS J-band photometry. NR 24 TC 7 Z9 7 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 SEP 20 PY 2008 VL 685 IS 1 BP L5 EP L8 DI 10.1086/592273 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 398KK UT WOS:000262730800002 ER PT J AU Taherion, S Armstrong, TP Garrett, HB AF Taherion, Saeed Armstrong, Thomas P. Garrett, Henry B. TI ULTRARELATIVISTIC ELECTRONS IN JUPITER'S INNER MAGNETOSPHERE: FIRST OBSERVATION OF ANGULAR DISTRIBUTIONS IN THE 2.5 TO 6 R-J REGION SO ASTROPHYSICAL JOURNAL LETTERS LA English DT Article DE instrumentation: detectors; methods: data analysis; planets and satellites: general; space vehicles: instruments ID SYNCHROTRON RADIATION AB Jupiter has been recognized as a probable location of magnetically trapped ultrarelativistic electrons since its discovery as a source of polarized decimeter radio waves. A series of spacecraft (Pioneers 10 and 11, Voyagers 1 and 2, Ulysses, Cassini, and New Horizons) have flown by and orbited Jupiter with the goal of observing the trapped radiation that generates the radio waves. Follow-on studies have attempted to reconcile intensity patterns of Jovian radio emission with direct measurements of ultrarelativistic electrons that radiate via a synchrotron process. These studies have been limited by the absence of observations of measurement of the angular distributions of ultrarelativistic electrons. Since the strongest synchrotron emission from an electron occurs near its mirror point, the distribution of synchrotron emission is expected to follow the distribution of the mirror points. From the description of magnetic trapping, it further follows that observing the angular distribution at low magnetic latitudes allows one to infer the distribution of mirror points along the magnetic field. Observations made with the Energetic Particle Detector aboard the Galileo orbiter during its penultimate Jovian orbit provided excellent angular distribution observations on the magnetic field lines containing the electrons which account for most of the Jovian decimeter radiation. Because ultrarelativistic electrons are especially difficult to observe directly with low-mass flight instruments, inferring angular distributions for such particles required extensive modeling of instrument responses that matched the observations. We report these results here and suggest their implications for past and future studies of astrophysical synchrotron emission. C1 [Taherion, Saeed; Armstrong, Thomas P.] Fundamental Technol LLC, Lawrence, KS 66046 USA. [Garrett, Henry B.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Taherion, S (reprint author), Fundamental Technol LLC, 2411 Ponderosa,Suite A, Lawrence, KS 66046 USA. EM Armstrong@ftecs.com; Henry.Garrett@jpl.nasa.gov NR 12 TC 1 Z9 1 U1 1 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 2041-8205 EI 2041-8213 J9 ASTROPHYS J LETT JI Astrophys. J. Lett. PD SEP 20 PY 2008 VL 685 IS 1 BP L79 EP L82 DI 10.1086/592270 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 398KK UT WOS:000262730800020 ER PT J AU Wang, JW Wang, K Pielke, RA Lin, JC Matsui, T AF Wang, Jih-Wang Wang, Ke Pielke, Roger A., Sr. Lin, John C. Matsui, Toshihisa TI Towards a robust test on North America warming trend and precipitable water content increase SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID TROPOSPHERIC TEMPERATURE; ATMOSPHERE; SERIES; CYCLE AB An increase in the atmospheric moist content has been generally assumed when the lower-tropospheric temperature (T(col)) increases, with relative humidity holding steady. Rather than using simple linear regression, we propose a more rigorous trend detection method that considers time series memory. The autoregressive moving-average (ARMA) parameters for the time series of Tcol, precipitable water vapor (PWAV), and total precipitable water content (PWAT) from the North American Regional Reanalysis data were first computed. We then applied the Monte Carlo method to replicate the ARMA time series samples to estimate the variances of their Ordinary Least Square trends. Student's t tests showed that Tcol from 1979 to 2006 increased significantly; however, PWAV and PWAT did not. This suggests that atmospheric temperature and water vapor trends do not follow the conjecture of constant relative humidity over North America. We thus urge further evaluations of Tcol, PWAV, and PWAT trends for the globe. C1 [Wang, Jih-Wang] Univ Colorado, Dept Atmospher & Ocean Sci, Boulder, CO 80309 USA. [Wang, Ke] Colorado State Univ, Dept Stat, Ft Collins, CO 80523 USA. [Pielke, Roger A., Sr.] Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. [Lin, John C.] Univ Waterloo, Dept Earth & Environm Sci, Waterloo, ON N2L 3G1, Canada. [Matsui, Toshihisa] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Matsui, Toshihisa] Univ Maryland, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21201 USA. RP Wang, JW (reprint author), Univ Colorado, Dept Atmospher & Ocean Sci, Boulder, CO 80309 USA. EM jihwang@colorado.edu RI Pielke, Roger/A-5015-2009 FU University of Colorado at Boulder (CIRES/ATOC); NASA [NNX06AG74G_S02, NNX07AG35G] FX This study was substantially improved by the discussion with the scientists on Climate Science weblog (http://climatesci.colorado.edu) and anonymous reviewers. A special thank is to Dallas Staley for her careful editing. R. A. Pielke Sr. also received support for this study through the University of Colorado at Boulder (CIRES/ATOC). This research is supported by NASA grants NNX06AG74G_S02 and NNX07AG35G. NR 20 TC 5 Z9 6 U1 0 U2 6 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 SEP 19 PY 2008 VL 35 IS 18 AR L18804 DI 10.1029/2008GL034564 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 351AG UT WOS:000259395800002 ER PT J AU Kauhanen, J Siili, T Jarvenoja, S Savijarvi, H AF Kauhanen, Janne Siili, Tero Jarvenoja, Simo Savijarvi, Hannu TI The Mars limited area model and simulations of atmospheric circulations for the Phoenix landing area and season of operation SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID MARTIAN ATMOSPHERE; MESOSCALE MODEL; NUMERICAL-SIMULATION; DUST STORMS; SLOPE WINDS; SURFACE; PATHFINDER; DYNAMICS; SITES; CYCLE AB The Mars limited area model (MLAM) has been used to simulate Martian northern polar atmospheric circulation phenomena during the planned season of the Phoenix Lander touching down on the surface (L-s approximate to 76 degrees). Initial and boundary conditions are from Thermal Emission Spectrometer observations assimilated via the United Kingdom Mars General Circulation Model. The higher-resolution north pole-centric nestings (grid lengths about 17-30 km and 8.5-15 km, respectively) resolve phenomena such as shallow mesoscale katabatic drainage flows spiraling out of the cold polar dome, strong valley winds out of Chasma Borealis, and diurnal slope winds embedded on the easterly basic flow, e. g., at Phoenix landing area D. There conditions appear to be mild (for Mars) and baroclinic activity is low. Low-level jets with wind speeds exceeding 20 m/s are, however, possible, but they are most likely nocturnal and would hence not endanger the early afternoon landing of Phoenix. Dust lifting is predicted for strong wind areas near the landing area B (where baroclinic activity appears to be high) and in the general area of the landing area D, primarily east of it. C1 [Kauhanen, Janne; Savijarvi, Hannu] Univ Helsinki, Dept Phys, FIN-00014 Helsinki, Finland. [Siili, Tero] NASA, Goddard Space Flight Ctr, European Space Agcy, SCI OSG SOHO,Directorate Sci & Robot Explorat, Greenbelt, MD 20771 USA. [Jarvenoja, Simo] Finnish Meteorol Inst, FIN-00101 Helsinki, Finland. RP Kauhanen, J (reprint author), Univ Helsinki, Dept Phys, POB 64, FIN-00014 Helsinki, Finland. EM janne.kauhanen@helsinki.fi NR 32 TC 10 Z9 10 U1 0 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 SEP 19 PY 2008 VL 113 AR E00A14 DI 10.1029/2007JE003011 PG 15 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 351AX UT WOS:000259397500001 ER PT J AU Bleacher, JE Greeley, R AF Bleacher, Jacob E. Greeley, Ronald TI Relating volcano morphometry to the developmental progression of Hawaiian shield volcanoes through slope and hypsometric analyses of SRTM data SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID KILAUEA VOLCANO; LAVA TUBES; LASER ALTIMETER; MAUNA-ULU; MOLA DATA; ERUPTION; GEOMORPHOMETRY; EMPLACEMENT; TOPOGRAPHY; LANDFORMS AB We calculated average and median slope values and produced hypsometric curves for the subaerial Hawaiian shield volcanoes using Shuttle Radar Topography Mission (SRTM) digital elevation models. The SRTM-derived average and median slope values display similar trends to published results based on other topographic data products, showing an increase in slope relative to volcano age. Shadows in the radar data over high relief regions reduce the slope values calculated for older volcanoes that have undergone significant erosion as compared to nonradar topographic data, suggesting that SRTM data are less sensitive to studies of erosion. Both the 1 and 3 arc sec SRTM data provide comparable results showing that the nearly global 3 arc sec data can be used to conduct the same studies for other volcanoes. Hypsometric analyses show that the Hawaiian shields maintain consistent upward and lateral growth until alkalic capping and subsidence alter the relief-surface area ratio. Changes in the morphology of the Hawaiian volcanoes are in part related to decreased magma production rates at older shields. The internal dynamics act to decrease the steadiness and duration of magma delivery to the surface causing a decrease in buffered eruptions and lava tube formation, all of which contribute to an increase in slope and relief-surface area ratios. Terrain analyses combined with mapping can provide insight into the development of remote volcanoes or volcanoes on other planets for which remotely sensed data exist but less is known about their internal and eruptive history. C1 [Bleacher, Jacob E.; Greeley, Ronald] Arizona State Univ, Sch Earth & Space Explorat, Tempe, AZ 85287 USA. [Bleacher, Jacob E.] NASA, Goddard Space Flight Ctr, Planetary & Geodynam Lab, Greenbelt, MD 20771 USA. RP Bleacher, JE (reprint author), Arizona State Univ, Sch Earth & Space Explorat, Tempe, AZ 85287 USA. EM jacob.e.bleacher@nasa.gov RI Bleacher, Jacob/D-1051-2012 OI Bleacher, Jacob/0000-0002-8499-4828 FU NASA Planetary Geology and Geophysics (PGG) [NAG5-13153]; NASA Graduate Student Research Program (GSRP) [NGT5-145]; NASA Postdoctoral Program (NPP) FX The authors would like to thank D. A. Williams and W. B. Garry for providing useful reviews of the manuscript and R. Arrowsmith for providing insight into this study. We also thank L. Keszthelyi, S. Fagents, and an anonymous reviewer for comments that improved this paper. This research was supported by NASA Planetary Geology and Geophysics (PG&G) grant NAG5-13153, NASA Graduate Student Research Program (GSRP) grant NGT5-145, and a NASA Postdoctoral Program (NPP) fellowship administered through Oak Ridge Associated Universities at Goddard Space Flight Center. NR 50 TC 4 Z9 4 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-SOL EA JI J. Geophys. Res.-Solid Earth PD SEP 19 PY 2008 VL 113 IS B9 AR B09208 DI 10.1029/2006JB004661 PG 8 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 351BC UT WOS:000259398000001 ER PT J AU Nakamura, T Noguchi, T Tsuchiyama, A Ushikubo, T Kita, NT Valley, JW Zolensky, ME Kakazu, Y Sakamoto, K Mashio, E Uesugi, K Nakano, T AF Nakamura, Tomoki Noguchi, Takaaki Tsuchiyama, Akira Ushikubo, Takayuki Kita, Noriko T. Valley, John W. Zolensky, Michael E. Kakazu, Yuki Sakamoto, Kanako Mashio, Etsuko Uesugi, Kentaro Nakano, Tsukasa TI Chondrulelike objects in short-period comet 81P/Wild 2 SO SCIENCE LA English DT Article ID COMET 81P/WILD-2; OXYGEN-ISOTOPE; CARBONACEOUS CHONDRITE; OLIVINE; MINERALOGY; STARDUST; SAMPLES; INCLUSIONS; DIFFUSION; PETROLOGY AB The Stardust spacecraft returned cometary samples that contain crystalline material, but the origin of the material is not yet well understood. We found four crystalline particles from comet 81P/ Wild 2 that were apparently formed by flash- melting at a high temperature and are texturally, mineralogically, and compositionally similar to chondrules. Chondrules are submillimeter particles that dominate chondrites and are believed to have formed in the inner solar nebula. The comet particles show oxygen isotope compositions similar to chondrules in carbonaceous chondrites that compose the middle- to- outer asteroid belt. The presence of the chondrulelike objects in the comet suggests that chondrules have been transported out to the cold outer solar nebula and spread widely over the early solar system. C1 [Nakamura, Tomoki; Kakazu, Yuki; Sakamoto, Kanako] Kyushu Univ, Fac Sci, Dept Earth & Planetary Sci, Fukuoka 8128581, Japan. [Noguchi, Takaaki] Ibaraki Univ, Coll Sci, Bunkyo Ku, Mito, Ibaraki 3108512, Japan. [Tsuchiyama, Akira; Mashio, Etsuko] Osaka Univ, Dept Earth & Space Sci, Grad Sch Sci, Toyonaka, Osaka 5600043, Japan. [Ushikubo, Takayuki; Kita, Noriko T.; Valley, John W.] Univ Wisconsin, Dept Geol & Geophys, Madison, WI 53706 USA. [Zolensky, Michael E.] NASA, Lyndon B Johnson Space Ctr, Astromat Res & Explorat Sci, Houston, TX 77058 USA. [Uesugi, Kentaro] Japan Synchrotron Radiat Res Inst, SPring 8, Sayo, Hyogo 6795198, Japan. [Nakano, Tsukasa] Natl Inst Adv Ind Sci & Technol, Geol Survey Japan, Tsukuba, Ibaraki 3058567, Japan. RP Nakamura, T (reprint author), Kyushu Univ, Fac Sci, Dept Earth & Planetary Sci, Fukuoka 8128581, Japan. EM tomoki@geo.kyushu-u.ac.jp RI Valley, John/B-3466-2011; U-ID, Kyushu/C-5291-2016; Kita, Noriko/H-8035-2016 OI Valley, John/0000-0003-3530-2722; Kita, Noriko/0000-0002-0204-0765 FU Japan Society for the Promotion of Science; NASA Stardust Sample Analysis; Cosmochemistry Programs; NSF FX We thank K. Nakamura-Messenger, T. Iwazumi, Y. Wakabayashi, A. Koyama, T. Mori, Y. Suzuki, A. Takeuchi, Y. Terada, H. Nagahara, and H. Yoshida for technical support; M. Sekiya, H. Miura, and M. Uesugi for discussion; and KEK and SPring-8 for experiments. This work was supported by the Japan Society for the Promotion of Science, the NASA Stardust Sample Analysis, and Cosmochemistry Programs. The Wisconsin Secondary Ion Mass Spectrometer Laboratory is partly supported by NSF. NR 30 TC 150 Z9 150 U1 0 U2 8 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 SEP 19 PY 2008 VL 321 IS 5896 BP 1664 EP 1667 DI 10.1126/science.1160995 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 349RG UT WOS:000259300400031 PM 18801994 ER PT J AU McComas, DJ Ebert, RW Elliott, HA Goldstein, BE Gosling, JT Schwadron, NA Skoug, RM AF McComas, D. J. Ebert, R. W. Elliott, H. A. Goldstein, B. E. Gosling, J. T. Schwadron, N. A. Skoug, R. M. TI Weaker solar wind from the polar coronal holes and the whole Sun SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID HELIOSPHERIC MAGNETIC-FIELD; TERMINATION SHOCK; ULYSSES; MAXIMUM; HELIOSHEATH; NORTHERN; REGION; PLASMA AB Observations of solar wind from both large polar coronal holes (PCHs) during Ulysses' third orbit showed that the fast solar wind was slightly slower, significantly less dense, cooler, and had less mass and momentum flux than during the previous solar minimum (first) orbit. In addition, while much more variable, measurements in the slower, in-ecliptic wind match quantitatively with Ulysses and show essentially identical trends. Thus, these combined observations indicate significant, long-term variations in solar wind output from the entire Sun. The significant, long-term trend to lower dynamic pressures means that the heliosphere has been shrinking and the heliopause must be moving inward toward the Voyager spacecraft. In addition, our observations suggest a significant and global reduction in the mass and energy fed in below the sonic point in the corona. The lower supply of mass and energy may result naturally from a reduction of open magnetic flux during this period. C1 [McComas, D. J.; Ebert, R. W.; Elliott, H. A.; Gosling, J. T.] SW Res Inst, Space Sci & Engn Div, San Antonio, TX 78228 USA. [McComas, D. J.; Ebert, R. W.] Univ Texas San Antonio, Dept Phys & Astron, San Antonio, TX USA. [Goldstein, B. E.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Gosling, J. T.] Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80303 USA. [Schwadron, N. A.] Boston Univ, Dept Astron, Boston, MA 02215 USA. [Skoug, R. M.] Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP McComas, DJ (reprint author), SW Res Inst, Space Sci & Engn Div, 6220 Culebra Rd, San Antonio, TX 78228 USA. EM dmccomas@swri.edu FU NASA FX We thank all the wonderful men and women who have made the Ulysses program such an outstanding success. For Figure 1, we also specifically thank the Ulysses magnetometer team for data used to identify the magnetic polarities and H. Morgan for help in assembling the images in the top right plot. Work at LANL was performed under the auspices of the U. S. DOE. This work was funded by NASA under the Ulysses program. NR 27 TC 236 Z9 236 U1 0 U2 0 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 SEP 18 PY 2008 VL 35 IS 18 AR L18103 DI 10.1029/2008GL034896 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 351AF UT WOS:000259395600003 ER PT J AU Hansell, RA Liou, KN Ou, SC Tsay, SC Ji, Q Reid, JS AF Hansell, R. A. Liou, K. N. Ou, S. C. Tsay, S. C. Ji, Q. Reid, J. S. TI Remote sensing of mineral dust aerosol using AERI during the UAE(2): A modeling and sensitivity study SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID EMITTED RADIANCE INTERFEROMETER; WATER-VAPOR; RADIATIVE PROPERTIES; SPECTRAL REGION; OPTICAL DEPTH; SCATTERING; CLOUD; PARTICLES; DATABASE; ALGORITHMS AB Numerical simulations and sensitivity studies have been performed to assess the potential for using brightness temperature spectra from a ground-based Atmospheric Emitted Radiance Interferometer (AERI) during the United Arab Emirates Unified Aerosol Experiment (UAE(2)) for detecting/retrieving mineral dust aerosol. A methodology for separating dust from clouds and retrieving the dust IR optical depths was developed by exploiting differences between their spectral absorptive powers in prescribed thermal IR window subbands. Dust microphysical models were constructed using in situ data from the UAE 2 and prior field studies while composition was modeled using refractive index data sets for minerals commonly observed around the UAE region including quartz, kaolinite, and calcium carbonate. The T-matrix, finite difference time domain (FDTD), and Lorenz-Mie light scattering programs were employed to calculate the single scattering properties for three dust shapes: oblate spheroids, hexagonal plates, and spheres. We used the Code for High-resolution Accelerated Radiative Transfer with Scattering (CHARTS) radiative transfer program to investigate sensitivity of the modeled AERI spectra to key dust and atmospheric parameters. Sensitivity studies show that characterization of the thermodynamic boundary layer is crucial for accurate AERI dust detection/retrieval. Furthermore, AERI sensitivity to dust optical depth is manifested in the strong subband slope dependence of the window region. Two daytime UAE 2 cases were examined to demonstrate the present detection/retrieval technique, and we show that the results compare reasonably well to collocated AERONET Sun photometer/MPLNET micropulse lidar measurements. Finally, sensitivity of the developed methodology to the AERI's estimated MgCdTe detector nonlinearity was evaluated. C1 [Hansell, R. A.; Ji, Q.] Univ Maryland, Earth Syst Sci Interdisciplinary Ctr, College Pk, MD 20742 USA. [Hansell, R. A.; Liou, K. N.; Ou, S. C.] Univ Calif Los Angeles, Dept Atmospher & Ocean Sci, Los Angeles, CA 90095 USA. [Reid, J. S.] USN, Res Lab, Monterey, CA 93943 USA. [Tsay, S. C.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Hansell, RA (reprint author), Univ Maryland, Earth Syst Sci Interdisciplinary Ctr, College Pk, MD 20742 USA. EM richard.a.hansell@nasa.gov RI Reid, Jeffrey/B-7633-2014; Tsay, Si-Chee/J-1147-2014; Hansell, Richard/J-2065-2014 OI Reid, Jeffrey/0000-0002-5147-7955; FU NASA Earth Observing System and Radiation Sciences Program; NASA [NNC5-712, NNG04GG91G]; DOE [DOE-FG03-00ER62] FX We are grateful to the Department of Water Resources, Office of the President (DWRS-United Arab Emirates), and Stuart Piketh (University of the Witwatersrand, Johannesburg, South Africa) for their logistical support and making this field study possible. We thank B. Kahn and A. Eldering at JPL/Caltech for making the CHARTS program available through AER. We also thank C. Zender (UCI) and T. Roush (NASA AMES) for making the mineral data sets available. The NASA Micropulse Lidar Network was funded by the NASA Earth Observing System and Radiation Sciences Program, and the AERONET site is maintained by B. Holben. We also thank J. Campbell for providing the SMART MPL data and W. Feltz for making available the AERIPLUS retrieval algorithm. Last, we are grateful to the reviewers of this manuscript for their helpful and insightful comments. J. S. Reid's participation was provided by the Office of Naval Research Code 322. This research was supported by NASA grants NNC5-712 and NNG04GG91G and DOE grant DOE-FG03-00ER62. NR 50 TC 12 Z9 12 U1 1 U2 5 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 SEP 17 PY 2008 VL 113 IS D18 AR D18202 DI 10.1029/2008JD010246 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 351AK UT WOS:000259396200006 ER PT J AU Lui, ATY Sibeck, DG Phan, T McFadden, JP Angelopoulos, V Glassmeier, KH AF Lui, A. T. Y. Sibeck, D. G. Phan, T. McFadden, J. P. Angelopoulos, V. Glassmeier, K. -H. TI Reconstruction of a flux transfer event based on observations from five THEMIS satellites SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID KELVIN-HELMHOLTZ VORTICES; MAGNETOPAUSE STRUCTURES; CLUSTER OBSERVATIONS; RECONNECTION; TRANSPORT; BOUNDARY AB We investigate a flux transfer event (FTE) observed by Time History of Events and Macroscale Interactions during Substorms (THEMIS) near the duskside magnetopause using the reconstruction technique based on solving the Grad-Shafranov equation; see review by Sonnerup et al. (2006). THEMIS D detected the FTE with the largest core magnetic field. THEMIS B and C observed deep troughs in the magnetic field associated with the FTE. THEMIS A and E sensed only slightly altered magnetic field from their surroundings. Two-dimensional reconstruction maps of magnetic field and plasma pressure are generated by combining observations from all five THEMIS satellites. These reconstructed maps show distinct differences between a magnetic island and an FTE in terms of vector potential and the derived plasma parameters. The origin of the magnetic field troughs in the crater FTEs can be traced to intrusions of the magnetosheath plasma around the structure in the reconstruction maps. Furthermore, the resulting maps show also cylindrical asymmetry in these parameters between the magnetosheath and magnetospheric sides of the FTE. This asymmetry and the different impact parameters of these satellites with respect to the FTE center together contribute to the different characteristics of the FTE signatures seen by the five THEMIS satellites. C1 [Lui, A. T. Y.] Johns Hopkins Appl Phys Lab, Laurel, MD 20723 USA. [Sibeck, D. G.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Phan, T.; McFadden, J. P.] Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. [Angelopoulos, V.] Univ Calif Los Angeles, IGPP, Los Angeles, CA 90095 USA. [Glassmeier, K. -H.] Tech Univ Carolo Wilhelmina Braunschweig, D-38106 Braunschweig, Germany. RP Lui, ATY (reprint author), Johns Hopkins Appl Phys Lab, 11100 Johns Hopkins Rd, Laurel, MD 20723 USA. EM tony.lui@jhuapl.edu RI Sibeck, David/D-4424-2012 FU NASA [NAS5-02099, NNX07AU74G]; NSF [ATM-0630912]; German Ministerium fur Wirtschaft und Technologie; German Zentrum fur Luft- und Raumfahrt [50QP0402] FX This work was supported by NASA grant NAS5-02099 to University of California, Berkeley, and by the NSF grant ATM-0630912 and NASA grant NNX07AU74G to The Johns Hopkins University Applied Physics Laboratory. The work of K. H. G. was financially supported by the German Ministerium fur Wirtschaft und Technologie and the German Zentrum fur Luft- und Raumfahrt under grant 50QP0402. NR 20 TC 14 Z9 15 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 SEP 17 PY 2008 VL 113 AR A00C01 DI 10.1029/2008JA013189 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 351BF UT WOS:000259398300001 ER PT J AU Prokopuk, N Son, KA AF Prokopuk, Nicholas Son, Kyung-Ah TI Alligator clips to molecular dimensions SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Review ID SELF-ASSEMBLED MONOLAYERS; SCANNING-TUNNELING-MICROSCOPY; NEGATIVE DIFFERENTIAL RESISTANCE; ELECTRON-TRANSPORT PROPERTIES; ATOMIC-FORCE MICROSCOPY; NANOGAP ELECTRODES; SINGLE MOLECULES; CHARGE-TRANSPORT; ORGANIC-MOLECULES; METALLIC NANOGAPS AB Techniques for fabricating nanospaced electrodes suitable for studying electron tunneling through metal-molecule-metal junctions are described. In one approach, top contacts are deposited/placed on a self-assembled monolayer or Langmuir-Blodgett film resting on a conducting substrate, the bottom contact. The molecular component serves as a permanent spacer that controls and limits the electrode separations. The top contact can be a thermally deposited metal film, liquid mercury drop, scanning probe tip, metallic wire or particle. Introduction of the top contact can greatly affect the electrical conductance of the intervening molecular film by chemical reaction, exerting pressure, or simply migrating through the organic layer. Alternatively, vacant nanogaps can be fabricated and the molecular component subsequently inserted. Strategies for constructing vacant nanogaps include mechanical break junction, electromigration, shadow mask lithography, focused ion beam deposition, chemical and electrochemical plating techniques, electron-beam lithography, and molecular and atomic rulers. The size of the nanogaps must be small enough to allow the molecule to connect both leads and large enough to keep the molecules in a relaxed and undistorted state. A significant advantage of using vacant nanogaps in the construction of metal-molecule-metal devices is that the junction can be characterized with and without the molecule in place. Any electrical artifacts introduced by the electrode fabrication process are more easily deconvoluted from the intrinsic properties of the molecule. C1 [Prokopuk, Nicholas] NAVAIR Res Dept, Chem Branch, China Lake, CA 93555 USA. [Son, Kyung-Ah] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Prokopuk, N (reprint author), NAVAIR Res Dept, Chem Branch, China Lake, CA 93555 USA. FU Office of Naval Research FX This work was funded by the Office of Naval Research. The research described in this paper was carried out partly at the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. NR 156 TC 19 Z9 19 U1 1 U2 18 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0953-8984 J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD SEP 17 PY 2008 VL 20 IS 37 AR 374116 DI 10.1088/0953-8984/20/37/374116 PG 21 WC Physics, Condensed Matter SC Physics GA 341SH UT WOS:000258734700018 PM 21694423 ER PT J AU Lean, JL Rind, DH AF Lean, Judith L. Rind, David H. TI How natural and anthropogenic influences alter global and regional surface temperatures: 1889 to 2006 SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID CLIMATE; IRRADIANCE AB To distinguish between simultaneous natural and anthropogenic impacts on surface temperature, regionally as well as globally, we perform a robust multivariate analysis using the best available estimates of each together with the observed surface temperature record from 1889 to 2006. The results enable us to compare, for the first time from observations, the geographical distributions of responses to individual influences consistent with their global impacts. We find a response to solar forcing quite different from that reported in several papers published recently in this journal, and zonally averaged responses to both natural and anthropogenic forcings that differ distinctly from those indicated by the Intergovernmental Panel on Climate Change, whose conclusions depended on model simulations. Anthropogenic warming estimated directly from the historical observations is more pronounced between 45 degrees S and 50 degrees N than at higher latitudes whereas the model-simulated trends have minimum values in the tropics and increase steadily from 30 to 70 degrees N. C1 [Lean, Judith L.] USN, Res Lab, Div Space Sci, Washington, DC 20375 USA. [Rind, David H.] NASA, Goddard Inst Space Studies, New York, NY 10025 USA. RP Lean, JL (reprint author), USN, Res Lab, Div Space Sci, Washington, DC 20375 USA. EM judith.lean@nrl.navy.mil OI Lean, Judith/0000-0002-0087-9639 FU NASA LWS; SORCE FX NASA LWS and SORCE funded this work. Data were obtained from http://www.cru.uea.ac.uk/, http://www.cdc.noaa.gov/ENSO/enso.mei_index.html and http://www.giss.nasa.gov/. Appreciated are efforts of the many scientists who maintain the various datasets and make them readily available. NR 16 TC 156 Z9 166 U1 1 U2 32 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 SEP 16 PY 2008 VL 35 IS 18 AR L18701 DI 10.1029/2008GL034864 PG 6 WC Geosciences, Multidisciplinary SC Geology GA 351AD UT WOS:000259395400001 ER PT J AU Tripathi, RK Wilson, JW Youngquist, RC AF Tripathi, Ram K. Wilson, John W. Youngquist, Robert C. TI Electrostatic space radiation shielding SO ADVANCES IN SPACE RESEARCH LA English DT Article DE electrostatic space radiation shielding; active radiation shielding; radiation shielding and protection; human space missions; space radiation exposure ID GALACTIC COSMIC-RADIATION; MODEL; EXPLORATION AB For the success of NASA's new vision for space exploration to Moon, Mars and beyond, exposures from the hazards of severe space radiation in deep space long duration missions is 'a must solve' problem. The payload penalty demands a very stringent requirement on the design of the spacecrafts for human deep space missions. The exploration beyond low Earth orbit (LEO) to enable routine access of space will require protection from the hazards of the accumulated exposures of space radiation, Galactic Cosmic Rays (GCR) and Solar Particle Events (SPE), and minimizing the production of secondary radiation is a great advantage. There is a need to look to new horizons for newer technologies. The present investigation revisits electrostatic active radiation shielding and explores the feasibility of using the electrostatic shielding in concert with the state-of-the-art materials shielding and protection technologies. The full space radiation environment has been used, for the first time, to explore the feasibility of electrostatic shielding. The goal is to repel enough positive charge ions so that they miss the spacecraft without attracting thermal electrons. Conclusions are drawn for the future directions of space radiation protection. Published by Elsevier Ltd. on behalf of COSPAR. C1 [Tripathi, Ram K.; Wilson, John W.] NASA, Langley Res Ctr, Hampton, VA 23681 USA. [Youngquist, Robert C.] NASA, John F Kennedy Space Ctr, Kennedy Space Ctr, FL 32899 USA. RP Tripathi, RK (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. EM ram.k.tripathi@nasa.gov NR 17 TC 8 Z9 9 U1 1 U2 7 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 SEP 15 PY 2008 VL 42 IS 6 BP 1043 EP 1049 DI 10.1016/j.asr.2007.09.015 PG 7 WC Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA 352OP UT WOS:000259507000005 ER PT J AU Levine, HG Krikorian, AD AF Levine, Howard G. Krikorian, A. D. TI Changes in plant medium composition after a spaceflight experiment: Potassium levels are of special interest SO ADVANCES IN SPACE RESEARCH LA English DT Article DE spaceflight; microgravity; haplopappus; hemerocallis; plain nutrition; CHROMEX-01; STS-29 ID GROWTH AB We present results on the analysis of 100 mL medium samples extracted from sterilized foam (Smithers-Oasis, Kent OH) used to support the growth of a representative dicotyledon (Haplopappus gracilis) and a representative monocotyledon (Hemerocallis cv Autumn Blaze) in NASA's Plant Growth Unit (PGU) during a 5-day Space Shuttle flight and ground experiments. At recovery, the media remaining within replicate (n = 5) foam blocks (for both the spaceflight and ground experiments) were extracted under vacuum, filtered and subjected to elemental analyses. A unique aspect of this experiment was that all plants were either aseptically-generated tissue culture propagated plantlets or aseptic seedling clones. The design of the PGU facilitated the maintenance of asepsis throughout the mission (confirmed by post-flight microbial sampling) and thus any possible impact of microorganisms on medium composition was eliminated. Concentration levels of some elements remained the same, while some decreased and others increased. There was a significant two-fold difference between the final concentrations of potassium when the Earth-based and microgravity experiments were contrasted. (C) 2008 COSPAR. Published by Elsevier Ltd. All rights reserved. C1 [Levine, Howard G.] NASA, Appl Technol Directorate, Kennedy Space Ctr, FL 32899 USA. [Krikorian, A. D.] SUNY Stony Brook, Dept Biochem & Cell Biol, Stony Brook, NY 11794 USA. RP Levine, HG (reprint author), NASA, Appl Technol Directorate, Mail Code KT-B-1, Kennedy Space Ctr, FL 32899 USA. EM Howard.G.Levine@nasa.gov FU NASA FX Spaceflight experiments require extensive cooperation on many levels. Many of those to whom we are indebted must remain unnamed. We are particularly thankful to Robert Kann (SUNY at Stony Brook) and NASA managers Thora Halstead and William Munsey, without whom the experiment would never have materialized. The help of Bionetics personnel (especially Teresa Englert who oversaw the chemical analyses) is also gratefully acknowledged. This work was supported by NASA. NR 8 TC 1 Z9 2 U1 1 U2 4 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 SEP 15 PY 2008 VL 42 IS 6 BP 1060 EP 1065 DI 10.1016/j.asr.2008.03.019 PG 6 WC Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA 352OP UT WOS:000259507000007 ER PT J AU Szewczyk, NJ Tillman, J Conley, CA Granger, L Segalat, L Higashitani, A Honda, S Honda, Y Kagawa, H Adachi, R Higashibata, A Fujimoto, N Kuriyama, K Ishioka, N Fukui, K Baillie, D Rose, A Gasset, G Eche, B Chaput, D Viso, M AF Szewczyk, N. J. Tillman, J. Conley, C. A. Granger, L. Segalat, L. Higashitani, A. Honda, S. Honda, Y. Kagawa, H. Adachi, R. Higashibata, A. Fujimoto, N. Kuriyama, K. Ishioka, N. Fukui, K. Baillie, D. Rose, A. Gasset, G. Eche, B. Chaput, D. Viso, M. TI Description of international Caenorhabditis elegans experiment first flight (ICE-FIRST) SO ADVANCES IN SPACE RESEARCH LA English DT Article DE Caenorhabditis elegans; spaceflight; development; axenic culture; astrobiology ID CHEMICALLY-DEFINED MEDIUM; NERVOUS-SYSTEM; HUMAN-DISEASE; C-ELEGANS; SPACE; SPACEFLIGHT; TRANSCRIPTION; EXPRESSION; NEMATODES; RADIATION AB Traveling, living and working in space is now a reality. The number of people and length of time in space is increasing. With new horizons for exploration it becomes more important to fully understand and provide countermeasures to the effects of the space environment oil the human body. In addition, space provides a unique laboratory to study how life and physiologic functions adapt from the cellular level to that of the entire organism. Caenorhabditis elegans is a genetic model organism used to study physiology on Earth. Here we provide a description of the rationale, design, methods, and space culture validation of the ICE-FIRST payload, which engaged C. elegans researchers from four nations. Here we also show C elegans growth and development proceeds essentially normally in a chemically defined liquid medium oil board the International Space Station (10.9 day round trip). By setting flight constraints first and bringing together established C. elegans researchers second, we were able to use minimal stowage space to successfully return a total of 53 independent samples, each containing more than a hundred individual animals, to investigators within one year of experiment concept. We believe that in the future, bringing together individuals with knowledge of flight experiment operations, flight hardware, space biology, and genetic model organisms should yield similarly successful payloads. Published by Elsevier Ltd. on behalf of COSPAR. C1 [Szewczyk, N. J.] Univ Nottingham, Derby City Hosp, Sch Grad Entry Med & Hlth, Derby DE22 3DT, England. [Szewczyk, N. J.] Univ Pittsburgh, Dept Biol Sci, Pittsburgh, PA 15260 USA. [Tillman, J.] Lockheed Martin, Moffett Field, CA 94035 USA. [Conley, C. A.] NASA, Moffett Field, CA 94035 USA. [Granger, L.; Segalat, L.] Univ Lyon 1, CNRS, CGMC, UMR 5534, F-69622 Villeurbanne, France. [Higashitani, A.] Tohoku Univ, Grad Sch Life Sci, Sendai, Miyagi 9808557, Japan. [Honda, S.; Honda, Y.] Tokyo Metropolitan Inst Gerontol, Tokyo 1730015, Japan. [Kagawa, H.; Adachi, R.] Okayama Univ, Grad Sch Nat Sci & Technol, Okayama 7008530, Japan. [Higashibata, A.; Fujimoto, N.; Kuriyama, K.; Ishioka, N.] Japan Aerosp Explorat Agcy, Tsukuba, Ibaraki 3058505, Japan. [Fukui, K.] Japan Space Forum, Tokyo 1000004, Japan. [Baillie, D.; Rose, A.] Univ British Columbia, Vancouver, BC V5Z 1M9, Canada. [Gasset, G.; Eche, B.] Univ Toulouse 3, Groupement Sci Biol & Med Spatiales, F-31062 Toulouse, France. [Chaput, D.; Viso, M.] Ctr Natl Estudes Spatiales, Paris 01, France. RP Szewczyk, NJ (reprint author), Univ Nottingham, Derby City Hosp, Sch Grad Entry Med & Hlth, Derby DE22 3DT, England. EM nate@alumni.cmu.edu RI Higashitani, Atsushi/G-7086-2015; Adachi, Ryota/I-7067-2014; OI Higashitani, Atsushi/0000-0001-6920-0594; Szewczyk, Nathaniel/0000-0003-4425-9746 FU CNES; NASA; JAXA; CSA FX The Dutch Soyuz mission, DELTA, was facilitated by the Dutch Government. Funding for this experiment was provided by CNES, NASA, JAXA, and CSA. Thanks to Professor Eberhard Horn for use of the modified EC1s. Thanks to Dr. Andre Kuipers, Cdr. Gannady Padalka, Fit. Eng. Michael Fincke, Cdr. Michael Foale, and Fit. Eng. Alexander Kaleri for in-flight payload operations and support. Thanks to Comat, ESA, Roscosmos and Energia for payload support. NR 43 TC 11 Z9 12 U1 0 U2 12 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 SEP 15 PY 2008 VL 42 IS 6 BP 1072 EP 1079 DI 10.1016/j.asr.2008.03.017 PG 8 WC Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA 352OP UT WOS:000259507000009 PM 22146801 ER PT J AU Barengoltz, J Witte, J AF Barengoltz, J. Witte, J. TI Planetary protection implementation on Mars Reconnaissance Orbiter mission SO ADVANCES IN SPACE RESEARCH LA English DT Article DE planetary protection; Mars Reconnaissance Orbiter; Mars; breakup and burn-up analysis AB In August 2005 NASA launched a large orbiting science observatory, the Mars Reconnaissance Orbiter (MRO), for what is scheduled to be a 5.4-year mission. High resolution imaging of the surface is a principal goal of the mission, One consequence of this goal however is the need for a low science orbit. Unfortunately this orbit fails the required 20-year orbit life set in NASA Planetary Protection (PP) requirements [NASA. Planetary protection provisions for robotic extraterrestrial missions, NASA procedural requirements NPR 8020.12C, NASA HQ, Washington, DC, April 2005.]. So rather than sacrifice the science goals of the mission by raising the science orbit, the MRO Project chose to be the first orbiter to pursue the bio-burden reduction approach. Cleaning alone for a large orbiter like MRO is insufficient to achieve the bio-burden threshold requirement in NASA PP requirements. The burden requirement for an orbiter includes spores encapsulated in non-metallic materials and trapped in joints, as well as located oil all internal and external surfaces (the total spore burden). Total burden estimates are dominated by the mated and encapsulated burden. The encapsulated burden cannot be cleaned. The total burden of a smaller orbiter (e.g., Mars Odyssey) likely could not have met the requirement by cleaning; for the large MRO it is clearly impossible. Of course, a system-level partial sterilization, with its attendant costs and system design issues, could have been employed. In the approach taken by the MRO Project, hardware which will burn up (completely vaporize or ablate) before reaching the surface or will at least attain high temperature(500 degrees C for 0.5 s or more) due to entry heating was exempt from burden accounting. Thus the bio-burden estimate was reduced. Lockheed Martin engineers developed a process to perform what is called breakup and burn-Lip (B&B) analysis.(2) The use of the B&B analysis to comply with the spore burden requirement is the main subject of this article. However, several components aboard the orbiter were predicted to fail the minimum time at temperature requirements (or could not conservatively be shown to meet the conditions). An implementation plan was generated to address the highest contributors to the bio-burden assessment that fail to meet the requirements. The spore burden for these components was estimated by direct and proxy burden assays, NASA PP specifications, and dry heat microbial reduction, as appropriate. Items oil the orbiter that required rework during assembly were also individually assessed. MRO met the spore burden requirement based on the B&B analysis, the MRO Planetary Protection Implementation Plan, and verification by the NASA Planetary Protection Officer's (PPO) independent assays. The compliance was documented in the MRO PP Pre-Launch Report. MRO was approved for flight by the NASA PPO. (C) 2007 COSPAR. Published by Elsevier Ltd. All rights reserved. C1 [Barengoltz, J.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Witte, J.] Lockheed Martin Space Syst Co, Littleton, CO 80125 USA. RP Barengoltz, J (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM jbarengoltz@earthlink.net NR 3 TC 1 Z9 1 U1 1 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 SEP 15 PY 2008 VL 42 IS 6 BP 1108 EP 1119 DI 10.1016/j.asr.2007.10.001 PG 12 WC Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA 352OP UT WOS:000259507000014 ER PT J AU Race, MS Kminek, G Rummel, JD AF Race, Margaret S. Kminek, Gerhard Rummel, John D. CA NASA ESA Planetary Protection Work TI Planetary protection and humans on Mars: NASA/ESA workshop results SO ADVANCES IN SPACE RESEARCH LA English DT Article DE planetary protection; human missions; Mars AB Planetary protection requirements for future human missions to Mars will strongly influence mission and spacecraft designs, particularly those related to the operation of advanced life support systems (ALS), extravehicular activity (EVA), laboratory and ill situ sampling operations, and associated environmental monitoring and control systems. In order to initiate communication, understanding and working relations among the ALS, EVA, and planetary protection communities in NASA and ESA, a workshop was held (May 2005; ESA/ESTEC; Nordwijk, The Netherlands) to focus on mission-specific planetary protection issues associated with future human missions to Mars. The "Mars Planetary Protection and Human Systems Research and Technology Joint NASA/ESA Workshop" considered the range of knowledge and information necessary to establish planetary protection requirements with respect to ALS and EVA systems, including the identification of potential contaminants. contamination pathways, and potential off-nominal events typical of such systems and of space exploration, The top-level workshop goal was to determine how compliance with planetary protection requirements should be implemented before, during, and after human Mars missions, and what standards of contamination control should apply to human explorers. Workshop discussions considered operations and technology concerns, science operations, backward contamination prevention requirements, and the protection of both the human habitat on Mars and the Earth upon crew return. A list of future research and development needs were also identified for ALS, EVA and Mars robotic missions, including specific precursor mission information necessary to understand and prepare for human support systems and science operations oil long duration Mars missions. This paper summarizes the findings and recommendations of the workshop including an overall approach to contamination control, waste and consumable management, and off-nominal events, as well as the research and development necessary to cope with planetary protection requirements during future human missions to Mars. (C) 2008 COSPAR. Published by Elsevier Ltd. All rights reserved. C1 [Race, Margaret S.] SETI Inst, Mountain View, CA 94043 USA. [Kminek, Gerhard] European Space Agcy, Human Spaceflight Micrograv & Explorat Directorat, NL-2200 AG Noordwijk, Netherlands. [Rummel, John D.] NASA Headquarters, Sci Mission Directorate, Washington, DC 20546 USA. RP Race, MS (reprint author), SETI Inst, 515 N Whisman Rd, Mountain View, CA 94043 USA. EM mracemom@aol.com NR 7 TC 7 Z9 7 U1 0 U2 4 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 SEP 15 PY 2008 VL 42 IS 6 BP 1128 EP 1138 DI 10.1016/j.asr.2008.03.003 PG 11 WC Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA 352OP UT WOS:000259507000016 ER PT J AU Schubert, W Plett, G Yavrouian, A Barengoltz, J AF Schubert, W. Plett, G. Yavrouian, A. Barengoltz, J. TI Viability of bacterial spores exposed to hydrazine SO ADVANCES IN SPACE RESEARCH LA English DT Article DE planetary protection; spore lethality; hydrazine ID BACILLUS-SUBTILIS; RESISTANCE AB For the purposes of planetary protection, a series of experiments were performed to answer a long-standing question about the potential of bacterial contamination of interplanetary spacecraft from liquid hydrazine. Spores of Bacillus atrophaeus (ATCC No. 9372, also known as Bacillus subtilis var. niger, and BSN) were exposed to hydrazine and survivors were enumerated using the NASA standard planetary protection pour plate assay. Results indicate that bulk hydrazine rocket propellant may be considered free of living bacterial cells for planetary protection compliance. (C) 2008 Published by Elsevier Ltd on behalf of COSPAR. C1 [Schubert, W.; Plett, G.; Yavrouian, A.; Barengoltz, J.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Barengoltz, J (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM jbarengoltz@earthlink.net FU Mars Program FX The work described in this paper was carried out at the Jet Propulsion Laboratory, California Institute of Technology under contract with the National Aeronautics and Space Administration. Funding was provided by the Mars Program at JPL. The authors thank Gayane Kazarians for processing some of the first bioassays. NR 10 TC 2 Z9 2 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 SEP 15 PY 2008 VL 42 IS 6 BP 1144 EP 1149 DI 10.1016/j.asr.2007.07.031 PG 6 WC Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA 352OP UT WOS:000259507000018 ER PT J AU Chung, S Kern, R Koukol, R Barengoltz, J Cash, H AF Chung, S. Kern, R. Koukol, R. Barengoltz, J. Cash, H. TI Vapor hydrogen peroxide as alternative to dry heat microbial reduction SO ADVANCES IN SPACE RESEARCH LA English DT Article DE hydrogen peroxide; sterilization; planetary protection AB The Jet Propulsion Laboratory (JPL), in conjunction with the NASA Planetary Protection Officer, has selected vapor phase hydrogen peroxide (VHP) sterilization process for continued development its a NASA approved sterilization technique for spacecraft subsystems and systems. The goal was to include this technique, with an appropriate specification, in NASA Procedural Requirements 8020.12 as it low-temperature complementary technique to the dry heat sterilization process. The VHP process is widely used by the medical industry to sterilize surgical instruments and biomedical devices, but high doses of VHP may degrade the performance of flight hardware, or compromise material compatibility. The goal for this study was to determine the minimum VHP process conditions for planetary protection acceptable microbial reduction levels. Experiments were conducted by the STERIS Corporation, under contract to JPL, to evaluate the effectiveness of vapor hydrogen peroxide for the inactivation of the standard spore challenge, Geobacillus stearothermophilus. VHP process parameters were determined that provide significant reductions in spore viability while allowing survival of sufficient spores for statistically significant enumeration. In addition to the obvious process parameters of interest: hydrogen peroxide concentration, number of injection cycles, and exposure duration, the investigation also considered the possible effect oil lethality of environmental parameters: temperature, absolute humidity, and material substrate. This Study delineated a range of test sterilizer process conditions: VHP concerti ration, process duration, a process temperature range for which the worst case D-value may be imposed, a process humidity range for which the worst case D-value may be imposed, and the dependence oil selected spacecraft material substrates. The derivation of D-values from the lethality data permitted conservative planetary protection recommendations. (C) 2008 COSPAR. Published by Elsevier Ltd. All rights reserved. C1 [Chung, S.; Kern, R.; Koukol, R.; Barengoltz, J.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Cash, H.] STERIS Corp, Mentor, OH 44060 USA. RP Barengoltz, J (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM jbarengoltz@earthlink.net NR 13 TC 16 Z9 17 U1 2 U2 9 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 SEP 15 PY 2008 VL 42 IS 6 BP 1150 EP 1160 DI 10.1016/j.asr.2008.01.005 PG 11 WC Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA 352OP UT WOS:000259507000019 ER PT J AU Rohrssen, M Brunner, B Mielke, RE Coleman, M AF Rohrssen, Megan Brunner, Benjamin Mielke, Randall E. Coleman, Max TI Method for simultaneous oxygen and hydrogen isotope analysis of water of crystallization in hydrated minerals SO ANALYTICAL CHEMISTRY LA English DT Article ID RATIO MASS-SPECTROMETRY; GYPSUM; CONVERSION; FRACTIONATION; TEMPERATURE; EXTRACTION; ABUNDANCES; PRECISION; H-2/H-1; SAMPLES AB The isotopic composition of water in hydrated minerals, such as gypsum and jarosite, has numerous applications in studies of recent climate change, ore formation, and soil development. However, oxygen and hydrogen isotope analysis of water of crystallization is currently a complex procedure. Commonly used techniques involve offline extraction of water from hydrated minerals and subsequent isotope analysis. Such methods are time-consuming, require relatively large sample sizes, and the stepwise procedure has to be carried out with extreme caution to avoid erroneous results. We present a novel online method for the oxygen and hydrogen isotope analysis of water of crystallization in hydrous minerals. Gypsum (CaSO4 center dot 2H(2)O) samples, 2 mg in size, are reacted in a simply modified carbon reducing furnace connected to a continuous-flow mass spectrometer system. Analysis time is less than 10 min/sample. The precision (2 std dev mean) of our method for 2-mg gypsum (30 mu mol of H2O) samples is 0.3 parts per thousand for oxygen and less than 1.4 parts per thousand for hydrogen isotope measurements. For oxygen isotope analysis alone, samples as small as 0.2 mg of gypsum can be analyzed with a precision of 0.3 parts per thousand. C1 [Rohrssen, Megan; Brunner, Benjamin; Mielke, Randall E.; Coleman, Max] CALTECH, Jet Prop Lab, Planetary Sci & Life Detect Sect, Pasadena, CA 91109 USA. RP Coleman, M (reprint author), CALTECH, Jet Prop Lab, Planetary Sci & Life Detect Sect, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM max.coleman@jpl.nasa.gov RI Coleman, Max/A-1303-2007; Brunner, Benjamin/F-2027-2011 OI Coleman, Max/0000-0002-5514-1826; FU National Aeronautics and Space Administration (NASA); JPL's Research and Technology Development Program [01STCR-R.07.023.011] FX This research was carried out by the Jet Propulsion Laboratory (JPL), California Institute of Technology, under contract with the National Aeronautics and Space Administration (NASA) with support from JPL's Research and Technology Development Program via a grant (01STCR-R.07.023.011) to M.C. XRD analysis was conducted by Bill Abbey, also at the jet Propulsion Laboratory. We are grateful to two anonymous reviewers whose detailed readings and constructive comments have helped us present our results much more clearly. NR 26 TC 1 Z9 1 U1 0 U2 11 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD SEP 15 PY 2008 VL 80 IS 18 BP 7084 EP 7089 DI 10.1021/ac800618p PG 6 WC Chemistry, Analytical SC Chemistry GA 348GQ UT WOS:000259199400031 PM 18714967 ER PT J AU Bogard, DD Garrison, DH AF Bogard, Donald D. Garrison, Daniel H. TI Ar-39-Ar-40 age and thermal history of martian dunite NWA 2737 SO EARTH AND PLANETARY SCIENCE LETTERS LA English DT Article DE martian meteorite; Ar-Ar ages; thermal history ID NOBLE-GASES; METEORITES; CHASSIGNITE; SHERGOTTITES; EJECTION; NWA-2737 AB We report an Ar-39-Ar-40 age determination of a whole rock sample of the olivine-rich, martian m-48% of the Ar-39 define an Ar-39-Ar-40 isochron age of 160-190 Ma, when evaluated in various ways. Higher temperature extractions show increasing ages that eventually exceed the reported Sm-Nd age of 1.42 Ga. At least part of this excess Ar-40 may have been shock implanted from the martian atmosphere. We considered two possible interpretations of the Ar-Ar isochron age, utilizing the measured Ar diffusion characteristics of NWA 2737 and a thermal model, which relates Ar diffusion to the size of a cooling object after shock heating. One interpretation, that Ar-40 was only partially degassed by an impact event similar to 11 Ma ago (the CRE age), appears possible only if NWA 2737 was shock-heated to temperatures >600 degrees C and was ejected from Mars as an object a few 10 s of cm in diameter. The second interpretation which we prefer is that NWA experienced an,, p earlier, more intense shock event, which left it residing in a warm ejecta layer, and a less intense event similar to 11 Ma ago, which ejected it into space. Our evaluation would require NWA 2737 to have been heated by this first event to a temperature of similar to 300500 degrees C and buried in ejecta to a depth of similar to 1-20 m. These conclusions are compared to model constraints on meteorite ejection from Mars reported in the literature. The second, Mars-ejection impact similar to 11 Ma ago probably heated NWA 2737 to no more than similar to 400 degrees C. NWA 2737 demonstrates that some martian meteorites probably experienced shock heating in events that did not eject them into space. Published by Elsevier B.V. C1 [Bogard, Donald D.] NASA, Lyndon B Johnson Space Ctr, ARES, Code KR, Houston, TX 77058 USA. [Garrison, Daniel H.] ESCD Barrios, Houston, TX 77058 USA. RP Bogard, DD (reprint author), NASA, Lyndon B Johnson Space Ctr, ARES, Code KR, Houston, TX 77058 USA. EM donald.d.bogard@nasa.gov FU NASA's FX We thank Jean-Alix Barrat for furnishing the NWA 2737 sample. Funding support was provided by NASA's Cosmochemistry Program. Valuable reviews were provided by Bernard Marty and Tim Swindle. NR 35 TC 13 Z9 13 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0012-821X J9 EARTH PLANET SC LETT JI Earth Planet. Sci. Lett. PD SEP 15 PY 2008 VL 273 IS 3-4 BP 386 EP 392 DI 10.1016/j.epsl.2008.07.003 PG 7 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 358WU UT WOS:000259949000015 ER PT J AU Rankenburg, K Humayun, M Brandon, AD Herrin, JS AF Rankenburg, K. Humayun, M. Brandon, A. D. Herrin, J. S. TI Highly siderophile elements in ureilites SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID EARLY SOLAR-SYSTEM; TRACE-ELEMENT; PARENT BODY; IRON-METEORITES; ANTARCTIC UREILITES; EXPLOSIVE VOLCANISM; POLYMICT UREILITE; NEBULAR PROCESSES; NEARBY SUPERNOVA; OXYGEN-ISOTOPE AB The abundances of the highly siderophile elements (HSE) Ru, Pd, Re, Os, Ir, and Pt were determined by isotope dilution mass spectrometry for 22 ureilite bulk rock samples, including monomict, augite-bearing, and polymict lithologies. This report adds significantly to the quantity of available Pt and Pd abundances in ureilites, as these elements were rarely determined in previous neutron activation studies. The Cl-normalized HSE abundance patterns of all ureilites analyzed here except ALHA 81101 show marked depletions in the more volatile Pd, with CI chondrite-normalized Pd/Os ratios (excluding ALHA 81101) averaging 0.19 +/- 0.23 (2 sigma). This value is too low to be directly derived from any known chondrite group. Instead, the HSE bulk rock abundances and HSE interelement ratios in ureilites can be understood as physical mixtures of two end member compositions. One component, best represented by sample ALHA 78019, is characterized by superchondritic abundances of refractory HSE (RHSE-Ru, Re, Os, Ir, and Pt), but subchondritic Pd/RHSE, and is consistent with residual metal after extraction of a S-bearing metallic partial melt from carbonaceous chondrite-like precursor materials. The other component, best represented by sample ALHA 81101, is RHSE-poor and has HSE abundances in chondritic proportions. The genesis of the second component is unclear. It could represent regions within the ureilite parent body (UPB), in which metallic phases were completely molten and partially drained, or it might represent chondritic contamination that was added during disruption and brecciation of the UPB. Removal of carbon-rich melts does not seem to play an important role in ureilite petrogenesis. Removal of such melts would quickly deplete the ureilite precursors in Re/Os and As/Au, which is inconsistent with measured osmium isotope abundances, and also with literature As/Au data for the ureilites. Removal of Al-26 during silicate melting may have acted as a switch that turned off further metal extraction from ureilite source regions. (C) 2008 Elsevier Ltd. All rights reserved. C1 [Rankenburg, K.; Humayun, M.] Florida State Univ, Natl High Magnet Field Lab, Tallahassee, FL 32310 USA. [Rankenburg, K.; Humayun, M.] Florida State Univ, Dept Geol Sci, Tallahassee, FL 32310 USA. [Brandon, A. D.; Herrin, J. S.] NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. RP Rankenburg, K (reprint author), European Sci Fdn, 1 Quai Lezay Marnesia,BP 90015, F-67080 Strasbourg, France. EM krankenburg@esf.org OI Herrin, Jason/0000-0002-2452-244X; Humayun, Munir/0000-0001-8516-9435 FU NASA Science Mission Directorate's Cosmochemistry [RTOP 344-31-72-06]; [NNG05GB81G]; [NNG06GF50G] FX We are grateful to the Astromaterials and Research Exploration Science Directorate at NASA-JSC for providing the Antarctic ureilite samples. We thank Glenn MacPherson, Linda Schramm, and the U.S. National Museum of Natural History in Washington for samples of Goalpara, Kenna and Novo-Urei. We also thank the Field Museum in Chicago for samples of Dyalpur and Jalanash. The manuscript greatly improved from comments made by G. Herzog, N. Chabot, H. Downes, and S. Singletary. KR was supported by a post-doctoral research appointment at NASA managed by the National Research Council and Oak Ridge Associated Universities. This research was funded by the NASA Science Mission Directorate's Cosmochemistry program under Grants RTOP 344-31-72-06 to A.D.B. and NNG05GB81G and NNG06GF50G to M.H. which is gratefully acknowledged. NR 98 TC 29 Z9 29 U1 1 U2 10 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 SEP 15 PY 2008 VL 72 IS 18 BP 4642 EP 4659 DI 10.1016/j.gca.2008.07.003 PG 18 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 346ZI UT WOS:000259107700014 ER PT J AU Condron, CL Kauzlarich, SM Ikeda, T Snyder, GJ Haarmann, F Jeglic, P AF Condron, Cathie L. Kauzlarich, Susan M. Ikeda, Teruyuki Snyder, G. Jeffrey Haarmann, Frank Jeglic, Peter TI Synthesis, structure, and high-temperature thermoelectric properties of boron-doped Ba(8)Al(14)Si(31) clathrate I phases SO INORGANIC CHEMISTRY LA English DT Article ID CRYSTAL-STRUCTURES; SINGLE-CRYSTALS; SR8GA16GE30; SPECTROSCOPY; BA8GA16GE30; BA8GA16SI30; BA8IN16SN30; IMPROVEMENT AB Single crystals of boron-doped Ba(8)Al(14)Si(31) clathrate I phase were prepared using Al flux growth. The structure and elemental composition of the samples were characterized by single-crystal and powder X-ray diffraction; elemental analysis; and multinuclear (21)Al, (11)B, and (29)Si solid-state NMR. The samples' compositions of Ba(8)B(0.17)Al(14)Si(31), Ba(8)B(0.19)Al(15)Si(31), and Ba(8)B(0.32)Al(14)Si(31) were consistent with the framework-deficient clathrate I structure Ba8Al(x)Si(42-3/4x)square(4-1/4x) (X = 14, square = lattice defect). Solid-state NMR provides further evidence for boron doped into the framework structure. Temperature-dependent resistivity indicates metallic behavior, and the negative Seebeck coefficient indicates that transport processes are dominated by electrons. Thermal conductivity is low, but not significantly lower than that observed in the undoped Ba(8)Al(14)Si(31) prepared in the same manner. C1 Univ Calif Davis, Dept Chem, Davis, CA 95616 USA. [Ikeda, Teruyuki; Snyder, G. Jeffrey] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Ikeda, Teruyuki; Snyder, G. Jeffrey] CALTECH, Pasadena, CA 91125 USA. [Haarmann, Frank; Jeglic, Peter] Max Planck Inst Chem Phys Fester Stoffe, D-01187 Dresden, Germany. RP Kauzlarich, SM (reprint author), Univ Calif Davis, Dept Chem, 1 Shields Ave, Davis, CA 95616 USA. EM smkauzlarich@ucdavis.edu RI Snyder, G. Jeffrey/E-4453-2011; Ikeda, Teruyuki/J-6176-2014; Snyder, G/I-2263-2015 OI Snyder, G. Jeffrey/0000-0003-1414-8682; Ikeda, Teruyuki/0000-0001-7076-6958; FU National Science Foundation [DMR-0600742]; Tyco Electronics Foundation Fellowship; NASA; Alexander von Humboldt foundation FX The authors gratefully acknowledge Dr. Alexandra Navrotsky (Department of Chemistry and Thermochemistry Facility and NEAT ORU, University of California Davis) for use of the Scintag powder diffractometer. This work was supported by the National Science Foundation (Grant DMR-0600742). C.L.C. acknowledges a Tyco Electronics Foundation Fellowship in functional materials. Portions of this work were carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with NASA. P.J. acknowledges financial support by the Alexander von Humboldt foundation. NR 35 TC 32 Z9 33 U1 2 U2 32 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 SEP 15 PY 2008 VL 47 IS 18 BP 8204 EP 8212 DI 10.1021/ic800772m PG 9 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 346UB UT WOS:000259093700037 PM 18710218 ER PT J AU Fu, JP Yang, RG Chen, G Fleurial, JP Snyder, GJ AF Fu, Jianping Yang, Ronggui Chen, Gang Fleurial, Jean Pierre Snyder, G. Jeffrey TI Integrated electroplated heat spreaders for high power semiconductor lasers SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID PHASE-LOCKED ARRAYS; HETEROSTRUCTURE LASERS; THERMAL-RESISTANCE; DIODE; PERFORMANCE; TRANSPORT AB Thermal management of high power semiconductor lasers is challenging due to the low thermal conductivity of the laser substrate and the active device layers. In this work, we demonstrate the use of a microfabricated laser test device to study the thermal management of edge emitting semiconductor lasers. In this device, metallic heat spreaders of high thermal conductivity are directly electroplated on structures that mimic edge-emitting semiconductor lasers. The effects of various structural parameters of the heat spreader on the reduction of the thermal resistance of the laser test device are demonstrated both experimentally and theoretically. Without resolving to computational costive simulations, we developed two independent analytical models to verify the experimental data and further utilized them to identify the dominant thermal resistance under different laser mounting configurations. We believe our approach here of using microfabricated devices to mimic thermal characteristics of lasers as well as the developed analytical models for calculating the laser thermal resistance under different mounting configurations can potentially become valuable tools for thermal management of high power semiconductor lasers. (C) 2008 American Institute of Physics. [DOI: 10.1063/1.2986888] C1 [Fu, Jianping; Yang, Ronggui; Chen, Gang] MIT, Dept Mech Engn, Cambridge, MA 02139 USA. [Fleurial, Jean Pierre; Snyder, G. Jeffrey] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Chen, G (reprint author), MIT, Dept Mech Engn, 77 Massachusetts Ave, Cambridge, MA 02139 USA. EM gchen2@mit.edu RI Snyder, G. Jeffrey/E-4453-2011; Yang, Ronggui/H-1278-2011; Fu, Jianping/C-9605-2009; Chen, Gang/J-1325-2014; Snyder, G/I-2263-2015 OI Snyder, G. Jeffrey/0000-0003-1414-8682; Fu, Jianping/0000-0001-9629-6739; Chen, Gang/0000-0002-3968-8530; FU DARPA HERETIC FX `We acknowledge financial support from DARPA HERETIC project (through JPL). We acknowledge valuable comments and suggestions on the manuscript by S. Pei and C. Dames. The UCLA Microfabrication Laboratory is acknowledged for support in fabrication. NR 22 TC 1 Z9 1 U1 0 U2 3 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 SEP 15 PY 2008 VL 104 IS 6 AR 064907 DI 10.1063/1.2986888 PG 11 WC Physics, Applied SC Physics GA 361HS UT WOS:000260119300167 ER PT J AU Myers, TA Nickerson, CA Kaushal, D Ott, CM Bentrup, KHZ Ramamurthy, R Nelman-Gonzalez, M Pierson, DL Philipp, MI AF Myers, Tereance A. Nickerson, Cheryl A. Kaushal, Deepak Ott, C. Mark Bentrup, Kerstin-Hoener Zu Ramamurthy, Rajee Nelman-Gonzalez, Mayra Pierson, Duane L. Philipp, Mario I. TI Closing the phenotypic gap between transformed neuronal cell lines in culture and untransformed neurons SO JOURNAL OF NEUROSCIENCE METHODS LA English DT Article DE neuroblastoma; 3D cell culture; differentiation; phenotype ID HUMAN NEUROBLASTOMA-CELLS; RNA-BINDING PROTEIN; ROTATING-WALL VESSEL; N-MYC OVEREXPRESSION; NERVE GROWTH-FACTOR; PC12 CELLS; NEURITE OUTGROWTH; ENDOPLASMIC-RETICULUM; GENE-EXPRESSION; INDUCED-DIFFERENTIATION AB Studies of neuronal dysfunction in the central nervous system (CNS) are frequently limited by the failure of primary neurons to propagate in vitro. Neuronal cell lines can be substituted for primary cells but they often misrepresent normal conditions. We hypothesized that a three-dimensional (31)) cell culture system would drive the phenotype of transformed neurons closer to that of untransformed cells, as has been demonstrated in non-neuronal cell lines. In our studies comparing 3D versus two-dimensional (21)) culture, neuronal SH-SY5Y (SY) cells underwent distinct morphological changes combined with a significant drop in their rate of cell division. Expression of the proto-oncogene N-myc and the RNA-binding protein HuD was decreased in 3D culture as compared to standard 2D conditions. We observed a decline in the anti-apoptotic protein Bcl-2 in 3D culture, coupled with increased expression of the pro-apoptotic proteins Bax and Bak. Moreover, thapsigargin (TG)-induced apoptosis was enhanced in the 3D cells. Microarray analysis demonstrated significantly differing mRNA levels for over 700 genes in the cells of the two culture types, and indicated that alterations in the G1/S cell-cycle progression contributed to the diminished doubling rate in the 3D-cultured SY cells. These results demonstrate that a 3D culture approach narrows the phenotypic gap between neuronal cell lines and primary neurons. The resulting cells may readily be used for in vitro research of neuronal pathogenesis. (C) 2008 Elsevier B.V. All rights reserved. C1 [Myers, Tereance A.; Kaushal, Deepak; Philipp, Mario I.] Tulane Univ, Hlth Sci Ctr, Tulane Natl Primate Res Ctr, Div Bacteriol & Parasitol, Covington, LA 70433 USA. [Myers, Tereance A.] Tulane Univ, Sch Med, Hlth Sci Ctr, Mol & Cellular Biol Program, New Orleans, LA 70112 USA. [Nickerson, Cheryl A.] Arizona State Univ, Biodesign Inst, Ctr Infect Dis & Vaccinol, Tempe, AZ 85287 USA. [Kaushal, Deepak; Bentrup, Kerstin-Hoener Zu; Philipp, Mario I.] Tulane Univ, Sch Med, Hlth Sci Ctr, Dept Microbiol & Immunol, New Orleans, LA 70112 USA. [Ott, C. Mark; Pierson, Duane L.] NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. [Ramamurthy, Rajee] Florida Int Univ, Dept Biol Sci, Miami, FL 33199 USA. [Nelman-Gonzalez, Mayra] NASA, Lyndon B Johnson Space Ctr, Wyle Labs, Houston, TX 77058 USA. RP Philipp, MI (reprint author), Tulane Univ, Hlth Sci Ctr, Tulane Natl Primate Res Ctr, Div Bacteriol & Parasitol, 18703 3 Rivers Rd, Covington, LA 70433 USA. EM philipp@tulane.edu FU National Institutes of Health [NS048952, RR00164] FX This work was supported by grants NS048952 and RR00164 (MTP) from the National Institutes of Health. We thank Robin Rodriguez for technical assistance with our figure images. NR 84 TC 21 Z9 21 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0165-0270 J9 J NEUROSCI METH JI J. Neurosci. Methods PD SEP 15 PY 2008 VL 174 IS 1 BP 31 EP 41 DI 10.1016/j.jneumeth.2008.06.031 PG 11 WC Biochemical Research Methods; Neurosciences SC Biochemistry & Molecular Biology; Neurosciences & Neurology GA 353HH UT WOS:000259556300005 PM 18672002 ER PT J AU Ozdogan, M Gutman, G AF Ozdogan, Mutlu Gutman, Garik TI A new methodology to map irrigated areas using multi-temporal MODIS and ancillary data: An application example in the continental US SO REMOTE SENSING OF ENVIRONMENT LA English DT Article DE irrigation; MODIS; agriculture; water; climate ID DIFFERENCE VEGETATION INDEX; PADDY RICE AGRICULTURE; LAND-COVER; MONITORING VEGETATION; SPATIAL-RESOLUTION; WATER-RESOURCES; SATELLITE DATA; CLIMATE; IMAGERY; AVHRR AB We present a dryland irrigation mapping methodology that relies on remotely sensed inputs from the MODerate Resolution Imaging Spectroradiometer (MODIS) instrument, globally extensive ancillary Sources Of gridded climate and agricultural data and on an advanced image classification algorithm. The methodology involves four steps. First, we use climate-based indices Of surface Moisture status and a map of cultivated areas to generate a potential irrigation index. Next, we identify remotely-sensed temporal and spectral signatures that are associated with presence of irrigation defined as full or partial artificial application of water to agricultural areas under dryland conditions excluding irrigated pastures, paddy rice fields, and other semiaquatic crops. Here, the temporal indices are based on the difference in annual evolution of greenness between irrigated and non-irrigated crops, while spectral indices are based on the reflectance in the green and are sensitive to vegetation chlorophyll content associated with moisture stress. Third, we combine the climate-based potential irrigation index, remotely sensed indices, and learning samples within a decision free supervised classification tool to make a binary irrigated/non-irrigated map. Finally, we apply a tree-based regression algorithm to derive the fraction of irrigated area within each pixel that has been identified as irrigated. Application of the proposed procedure over the continental US in the year 2001 produces an objective and comprehensive map that exhibits expected patterns: there is a strong east-west divide where the majority of irrigated areas is concentrated in the and west along dry lowland valleys. Qualitative assessment of the map across different climatic and agricultural zones reveals a high quality product with sufficient detail when compared to existing large area irrigation databases. Accuracy assessment indicates that the map is highly accurate in the western US but less accurate in the east. Comparison of area estimates made with the new procedure to those reported at the state and County levels shows a strong correlation with a small bias and an estimated RMSE of 2500 km(2), or little over 2% of the total irrigated area in the US. As a result, the future application of the new procedure at a global scale is promising but may require a better potential irrigation index, as well as the use of remotely sensed skin temperature measurements. (C) 2008 Elsevier Inc. All rights reserved. C1 [Ozdogan, Mutlu] Univ Wisconsin, Ctr SAGE, Madison, WI 53726 USA. [Gutman, Garik] NASA Headquarters, Div Earth Sci, Washington, DC 20546 USA. RP Ozdogan, M (reprint author), Univ Wisconsin, Ctr SAGE, 1710 Univ Ave, Madison, WI 53726 USA. EM ozdogan@wisc.edu OI Ozdogan, Mutlu/0000-0002-1707-3375 FU US National Research Council; NASA; NASA-GSFC FX This research was funded by the US National Research Council and NASA Postdoctoral Program Fellowships awarded to Mutlu Ozdogan. Dr. Ozdogan acknowledges generous computation and logistical support from the Hydrological Sciences Branch at NASA-GSFC. Suggestions by Drs. Anatoly Gitelson and Mark Friedl greatly improved this research. Discussion with Stefan Siebert of Frankfurt University and Prasad Thenkabail of IWMI greatly enhanced the scope of this research. Finally, three anonymous reviewers are thanked for greatly improving the quality of this Contribution. NR 68 TC 80 Z9 85 U1 3 U2 31 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 SEP 15 PY 2008 VL 112 IS 9 BP 3520 EP 3537 DI 10.1016/j.rse.2008.04.010 PG 18 WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic Technology SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science & Photographic Technology GA 342LD UT WOS:000258784700005 ER PT J AU Jin, ZH Charlock, TP Yang, P Xie, Y Miller, W AF Jin, Zhonghai Charlock, Thomas P. Yang, Ping Xie, Yu Miller, Walter TI Snow optical properties for different particle shapes with application to snow grain size retrieval and MODIS/CERES radiance comparison over Antarctica SO REMOTE SENSING OF ENVIRONMENT LA English DT Article DE snow; radiative transfer; radiance; snow grain size retrieval ID BIDIRECTIONAL REFLECTANCE; RADIATIVE-TRANSFER; SPECTRAL ALBEDO; SURFACE; ICE; ULTRAVIOLET; SCATTERING; SYSTEM AB We investigated the single scattering optical properties of snow for different ice particle shapes and degrees of microscopic scale roughness. These optical properties were implemented and tested in a coupled atmosphere-snow radiative transfer model. The modeled surface spectral albedo and radiance distribution were compared with surface measurements. The results Show that the reflected radiance and irradiance over snow are sensitive to the snow grain size and its vertical profile. When inhomogeneity of the particle size distribution in the vertical is taken into account, the measured spectral albedo can be matched, regardless of the particle shapes. But this is not true for the modeled radiance distribution, which depends a lot on the particle shape. The usual "equivalent spheres" assumption significantly overestimates forward reflected radiances, and underestimates backscattering radiances, around the principal plane. Oil average, the aggregate shape assumption has the best agreement with the measured radiances to a mean bias within 2%. The snow optical properties with the aggregate assumption were applied to the retrieval of snow grain size over the Antarctic plateau. The retrieved grain sizes of the top layer showed similar and large seasonal variation in all years, but only small year to year variation. Using the retrieved snow grain sizes, the modeled spectral and broadband radiances showed good agreements with MODIS and CERES measurements over the Antarctic plateau. Except for the MODIS 2.13 mu m channel, the mean relative model-observation differences are within few percent. The modeled MODIS radiances using measured surface reflectance at Dome C also showed good agreement in visible channels, where radiation is not sensitive to snow grain size and the measured Surface bidirectional reflectance is applicable Over the Antarctic plateau. But modeled radiances using local, surface-measured reflectance in the near infrared yielded large errors because of the high sensitivity to the snow grain size, which varies spatially and temporally. The CERES broadband shortwave radiance is moderately sensitive to the snow grain size, comparable to the MODIS 0.86 mu m channel. The variation of broadband snow reflectance due to the season a I variation in snow grain size is about 5% in a year over the Antarctic plateau. CERES broadband radiances simulated with grain sizes retrieved using MODIS are about 2% larger than those observed. (C) 2008 Elsevier Inc. All rights reserved. C1 [Jin, Zhonghai] Sci Syst & Applicat Inc, Hampton, VA 23666 USA. [Charlock, Thomas P.] NASA, Langley Res Ctr, Sci Directorate, Climate Sci Branch, Hampton, VA 23681 USA. [Yang, Ping; Xie, Yu] Texas A&M Univ, Dept Atmospher Sci, College Stn, TX 77843 USA. [Miller, Walter] Sci Syst & Applicat Inc, Hampton, VA 23666 USA. RP Jin, ZH (reprint author), Sci Syst & Applicat Inc, 1 Enterprise PKWY,STE 200, Hampton, VA 23666 USA. EM Zhonghai.Jin@nasa.gov RI Xie, Yu/A-4266-2011; Yang, Ping/B-4590-2011 NR 26 TC 35 Z9 38 U1 0 U2 12 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 SEP 15 PY 2008 VL 112 IS 9 BP 3563 EP 3581 DI 10.1016/j.rse.2008.04.011 PG 19 WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic Technology SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science & Photographic Technology GA 342LD UT WOS:000258784700008 ER PT J AU Imai, M Imai, K Higgins, CA Thieman, JR AF Imai, Masafumi Imai, Kazumasa Higgins, Charles A. Thieman, James R. TI Angular beaming model of Jupiter's decametric radio emissions based on Cassini RPWS data analysis SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID RADIATION; CYCLOTRON AB Observations of the low frequency part of Jupiter decameter wavelength (DAM) emissions were made using the Cassini radio and plasma wave science (RPWS) instrument. We have analyzed non-Io-DAM occurrence dependence from 4 MHz to 16 MHz based on the System III central meridian longitude (CML) of the Cassini spacecraft and calculated the occurrence probability for each frequency. As a result of this analysis, the two peaks of non-Io-B and non-Io-A occurrence probability showed a dramatic change in longitude between 9 MHz and 16 MHz. At 16 MHz two peaks of probability occurred at 160 degrees and 240 degrees CML. As the frequency decreases to 9 MHz, the two peaks converged to become one peak near 205 degrees CML at 9 MHz. This peak gradually disappeared below 9 MHz. Based on Jupiter's magnetic VIP4 model, an angular beaming model was made to explain these observational results by taking into account the decreasing cone half-angle of the emitting cone from 16 MHz down to 9 MHz. We found the active magnetic flux tubes of non-Io-B and non-Io-A sources are localized at about 180 degrees +/- 10 degrees of System III longitude projected on Jupiter's surface. C1 [Imai, Masafumi] Kochi Natl Coll Technol, Adv Course Mech & Elect Engn, Kochi 7838508, Japan. [Imai, Kazumasa] Kochi Natl Coll Technol, Dept Elect Engn, Kochi 7838508, Japan. [Higgins, Charles A.] Middle Tennessee State Univ, Dept Phys & Astron, Murfreesboro, TN 37132 USA. [Thieman, James R.] NASA, Goddard Space Flight Ctr, Solar Syst Explorat Div Serv Off, Greenbelt, MD 20771 USA. RP Imai, M (reprint author), Kochi Natl Coll Technol, Adv Course Mech & Elect Engn, Kochi 7838508, Japan. EM masafumi@jupiter.jp; imai@ee.kochi-ct.ac.jp; chiggins@mtsu.edu; james.r.thieman@nasa.gov RI Imai, Masafumi/S-8736-2016 OI Imai, Masafumi/0000-0002-2814-4036 FU Ministry of Education, Culture, Sports, Science and Technology [19340142] FX The authors are pleased to acknowledge the Cassini RPWS team for access to Cassini data at the Planetary Data System (PDS) and J. Groene for creating Cassini ephemeris tables. The authors are especially grateful to A. Lecacheux and H. Misawa for numerous discussions. This work was supported by the Ministry of Education, Culture, Sports, Science and Technology, Grant-in-Aid for Scientific Research (B), 19340142. NR 22 TC 7 Z9 7 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 SEP 13 PY 2008 VL 35 IS 17 AR L17103 DI 10.1029/2008GL034987 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 348GV UT WOS:000259199900005 ER PT J AU Mertens, CJ Fernandez, JR Xu, XJ Evans, DS Mlynczak, MG Russell, JM AF Mertens, Christopher J. Fernandez, Jose R. Xu, Xiaojing Evans, David S. Mlynczak, Martin G. Russell, James M., III TI A new source of auroral infrared emission observed by TIMED/SABER SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID ION-MOLECULE REACTION; DEPENDENCE; STORMS; NO+; N2 AB We demonstrate for the first time that O-2(+) + NO charge transfer produces NO+(v). This mechanism identifies a new source of auroral infrared emission at 4.3 mu m, which provides a major step forward in understanding auroral processes and a new context for understanding previously observed auroral enhancements in O-2(b(1)Sigma(+)(g)) and O-2(a(1)Delta(g)) bands. The charge transfer process is identified by comparing physics-based model simulations with NO+(v) volume emission rates derived from SABER 4.3 mu m limb emission measurements. C1 [Mertens, Christopher J.; Fernandez, Jose R.; Mlynczak, Martin G.] NASA, Langley Res Ctr, Hampton, VA 23681 USA. [Xu, Xiaojing] SSAI Inc, Hampton, VA 23666 USA. [Evans, David S.] NOAA, Space Weather Predict Ctr, Boulder, CO 80303 USA. [Russell, James M., III] Hampton Univ, Ctr Atmospher Sci, Hampton, VA 23688 USA. RP Mertens, CJ (reprint author), NASA, Langley Res Ctr, 21 Langley Blvd,Mail Stop 401B, Hampton, VA 23681 USA. EM c.j.mertens@larc.nasa.gov; j.fernand@naic.edu; xiaojing_xu@ssaihq.com; david.s.evans@noaa.gov; m.g.mlynczak@larc.nasa.gov; james.russell@hamptonu.edu RI Mlynczak, Martin/K-3396-2012 FU NASA Heliophysics Guest Investigator Program FX This work was supported by the NASA Heliophysics Guest Investigator Program. We are also grateful for insightful discussions with Jeremy R. Winick (Air Force Research Laboratories, Hanscom AFB, MA). NR 12 TC 7 Z9 7 U1 0 U2 1 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 SEP 13 PY 2008 VL 35 IS 17 AR L17106 DI 10.1029/2008GL034701 PG 6 WC Geosciences, Multidisciplinary SC Geology GA 348GV UT WOS:000259199900003 ER PT J AU Sanderson, MG Dentener, FJ Fiore, AM Cuvelier, C Keating, TJ Zuber, A Atherton, CS Bergmann, DJ Diehl, T Doherty, RM Duncan, BN Hess, P Horowitz, LW Jacob, DJ Jonson, JE Kaminski, JW Lupu, A MacKenzie, IA Mancini, E Marmer, E Park, R Pitari, G Prather, MJ Pringle, KJ Schroeder, S Schultz, MG Shindell, DT Szopa, S Wild, O Wind, P AF Sanderson, M. G. Dentener, F. J. Fiore, A. M. Cuvelier, C. Keating, T. J. Zuber, A. Atherton, C. S. Bergmann, D. J. Diehl, T. Doherty, R. M. Duncan, B. N. Hess, P. Horowitz, L. W. Jacob, D. J. Jonson, J. -E. Kaminski, J. W. Lupu, A. MacKenzie, I. A. Mancini, E. Marmer, E. Park, R. Pitari, G. Prather, M. J. Pringle, K. J. Schroeder, S. Schultz, M. G. Shindell, D. T. Szopa, S. Wild, O. Wind, P. TI A multi-model study of the hemispheric transport and deposition of oxidised nitrogen SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID ECOSYSTEMS; FUTURE AB Fifteen chemistry-transport models are used to quantify, for the first time, the export of oxidised nitrogen (NOy) to and from four regions (Europe, North America, South Asia, and East Asia), and to estimate the uncertainty in the results. Between 12 and 24% of the NOx emitted is exported from each region annually. The strongest impact of each source region on a foreign region is: Europe on East Asia, North America on Europe, South Asia on East Asia, and East Asia on North America. Europe exports the most NOy, and East Asia the least. East Asia receives the most NOy from the other regions. Between 8 and 15% of NOx emitted in each region is transported over distances larger than 1000 km, with 3-10% ultimately deposited over the foreign regions. C1 [Sanderson, M. G.; Pringle, K. J.] Met Off Hadley Ctr, Exeter, Devon, England. [Dentener, F. J.; Cuvelier, C.; Marmer, E.] Inst Environm & Sustainabil, DG JRC, European Commiss, Ispra, Italy. [Fiore, A. M.; Horowitz, L. W.] NOAA Geophys Fluid Dynam Lab, Princeton, NJ USA. [Keating, T. J.] US EPA, Off Policy Anal & Review, Washington, DC USA. [Zuber, A.] European Commiss, Environm Directorate Gen, Brussels, Belgium. [Atherton, C. S.; Bergmann, D. J.] Lawrence Livermore Natl Lab, Div Atmospher Sci, Livermore, CA USA. [Diehl, T.; Duncan, B. N.] UMBC, Goddard Earth Sci & Technol Ctr, Baltimore, MD USA. [Doherty, R. M.; MacKenzie, I. A.] Univ Edinburgh, Sch GeoSci, Edinburgh, Midlothian, Scotland. [Hess, P.] Natl Ctr Atmospher Res, Boulder, CO 80307 USA. [Jacob, D. J.; Park, R.] Harvard Univ, Atmospher Chem Modelling Grp, Cambridge, MA 02138 USA. [Jonson, J. -E.; Wind, P.] Norwegian Meteorol Inst, Oslo, Norway. [Kaminski, J. W.; Lupu, A.] York Univ, Ctr Res Earth & Space Sci, Toronto, ON M3J 2R7, Canada. [Mancini, E.; Pitari, G.] Univ Aquila, Dipartimento Fis, Laquila, Italy. [Prather, M. J.] Univ Calif Irvine, Irvine, CA USA. [Schroeder, S.; Schultz, M. G.] Forschungszentrum Julich, ICG2, Julich, Germany. [Shindell, D. T.] NASA, Goddard Inst Space Studies, New York, NY 10025 USA. [Shindell, D. T.] Columbia Univ, New York, NY USA. [Szopa, S.] Lab Sci Climat & Environm, Gif Sur Yvette, France. [Wild, O.] Univ Lancaster, Div Environm Sci, Lancaster LA1 4YQ, England. RP Sanderson, MG (reprint author), Met Off Hadley Ctr, Exeter, Devon, England. RI Pitari, Giovanni/O-7458-2016; Wild, Oliver/A-4909-2009; Szopa, Sophie/F-8984-2010; Schultz, Martin/I-9512-2012; Lupu, Alexandru/D-3689-2009; Bergmann, Daniel/F-9801-2011; Shindell, Drew/D-4636-2012; Duncan, Bryan/A-5962-2011; Pringle, Kirsty /A-4697-2013; mackenzie, ian/E-9320-2013; Horowitz, Larry/D-8048-2014; Park, Rokjin/I-5055-2012; Hess, Peter/M-3145-2015; OI Pitari, Giovanni/0000-0001-7051-9578; Wild, Oliver/0000-0002-6227-7035; Szopa, Sophie/0000-0002-8641-1737; Schultz, Martin/0000-0003-3455-774X; Lupu, Alexandru/0000-0002-4520-5523; Bergmann, Daniel/0000-0003-4357-6301; Horowitz, Larry/0000-0002-5886-3314; Park, Rokjin/0000-0001-8922-0234; Hess, Peter/0000-0003-2439-3796; Mancini, Eva/0000-0001-7071-0292 NR 13 TC 33 Z9 33 U1 1 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 SEP 13 PY 2008 VL 35 IS 17 AR L17815 DI 10.1029/2008GL035389 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 348GV UT WOS:000259199900008 ER PT J AU Young, PG Beresford-West, TBH Coward, SRL Notarberardino, B Walker, B Abdul-Aziz, A AF Young, P. G. Beresford-West, T. B. H. Coward, S. R. L. Notarberardino, B. Walker, B. Abdul-Aziz, A. TI An efficient approach to converting three-dimensional image data into highly accurate computational models SO PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES LA English DT Review DE biomechanics; finite element; finite volume; image-based meshing; material characterization; orthopaedics ID ELEMENT MESH GENERATION; TOTAL HIP-ARTHROPLASTY; MECHANICAL-PROPERTIES; STRESS DISTRIBUTIONS; ACETABULAR REGION; HUMAN FEMUR; PROSTHESIS; SIMULATION; COMPONENT; GRIDS AB Image-based meshing is opening up exciting new possibilities for the application of computational continuum mechanics methods (finite-element and computational fluid dynamics) to a wide range of biomechanical and biomedical problems that were previously intractable owing to the difficulty in obtaining suitably realistic models. Innovative surface and volume mesh generation techniques have recently been developed, which convert three-dimensional imaging data, as obtained from magnetic resonance imaging, computed tomography, micro-CT and ultrasound, for example, directly into meshes suitable for use in physics-based simulations. These techniques have several key advantages, including the ability to robustly generate meshes for topologies of arbitrary complexity (such as bioscaffolds or composite micro-architectures) and with any number of constituent materials (multi-part modelling), providing meshes in which the geometric accuracy of mesh domains is only dependent on the image accuracy (image-based accuracy) and the ability for certain problems to model material inhomogeneity by assigning the properties based on image signal strength. Commonly used mesh generation techniques will be compared with the proposed enhanced volumetric marching cubes (EVoMaCs) approach and some issues specific to simulations based on three-dimensional image data will be discussed. A number of case studies will be presented to illustrate how these techniques can be used effectively across a wide range of problems from characterization of micro-scaffolds through to head impact modelling. C1 [Young, P. G.; Beresford-West, T. B. H.; Coward, S. R. L.; Notarberardino, B.] Univ Exeter, Sch Engn Comp & Math, Exeter EX4 4QF, Devon, England. [Abdul-Aziz, A.] NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Young, PG (reprint author), Univ Exeter, Sch Engn Comp & Math, N Pk Rd, Exeter EX4 4QF, Devon, England. EM philippe.g.young@exeter.ac.uk NR 44 TC 83 Z9 84 U1 1 U2 14 PU ROYAL SOC PI LONDON PA 6-9 CARLTON HOUSE TERRACE, LONDON SW1Y 5AG, ENGLAND SN 1364-503X J9 PHILOS T R SOC A JI Philos. Trans. R. Soc. A-Math. Phys. Eng. Sci. PD SEP 13 PY 2008 VL 366 IS 1878 BP 3155 EP 3173 DI 10.1098/rsta.2008.0090 PG 19 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 330EI UT WOS:000257921900010 PM 18573757 ER PT J AU Curier, RL Veefkind, JP Braak, R Veihelmann, B Torres, O de Leeuw, G AF Curier, R. L. Veefkind, J. P. Braak, R. Veihelmann, B. Torres, O. de Leeuw, G. TI Retrieval of aerosol optical properties from OMI radiances using a multiwavelength algorithm: Application to western Europe SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID OZONE MONITORING INSTRUMENT; LAND; AERONET; AEROCOM; DEPTH; MODIS; GOME AB The Ozone Monitoring Instrument (OMI) multiwavelength algorithm has been developed to retrieve aerosol optical depth using OMI-measured reflectance at the top of the atmosphere. This algorithm was further developed by using surface reflectance data from a field campaign in Cabauw (The Netherlands), a new cloud-screening method, and a global aerosol database derived from the aerosol transport model TM5. The first results from an application of this algorithm over western Europe are presented. The OMI-retrieved aerosol optical depth is evaluated by comparison with both ground-based measurements from Aerosol Robotic Network (AERONET) and Moderate Resolution Imaging Spectroradiometer (MODIS) satellite data. The various aerosol optical depth values compare favorably, except in situations where large changes occur in the surface properties, which is illustrated over the Iberian peninsula. OMI and MODIS aerosol optical depth are well correlated (with a correlation coefficient of 0.66 over land and 0.79 over sea), although the multiwavelength algorithm appears to overestimate the aerosol optical depth values with respect to MODIS. The multiwavelength algorithm performs better over sea than over land. Qualitatively, the multiwavelength algorithm well reproduces the expected spatial aerosol optical depth gradient over western Europe. C1 [Veefkind, J. P.; Braak, R.; Veihelmann, B.] KNMI, NL-3730 AE De Bilt, Netherlands. [Torres, O.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Curier, R. L.; de Leeuw, G.] TNO Def Safety & Secur, The Hague, Netherlands. [de Leeuw, G.] Finnish Meteorol Inst, Helsinki, Finland. [de Leeuw, G.] Univ Helsinki, Dept Phys Sci, Helsinki, Finland. RP Curier, RL (reprint author), Finnish Meteorol Inst, Climate Change Unit, Erik Palmenin Aukio 1,POB 503, FI-00101 Helsinki, Finland. EM lyana.curier@gmail.com RI Torres, Omar/G-4929-2013 FU SRON (The Netherlands Space Research Organization); TNO internal funding; NIVR; KNMI FX The work described in this paper is supported by SRON (The Netherlands Space Research Organization) and TNO internal funding. OMI, a Dutch-Finnish instrument, is part of NASA's EOS Aura payload. The OMI project is managed by NIVR and KNMI in the Netherlands. The authors thank the different P.I.s for the AERONET Sun photometer data. NR 34 TC 28 Z9 28 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 SEP 12 PY 2008 VL 113 IS D17 AR D17S90 DI 10.1029/2007JD008738 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 348HC UT WOS:000259200600001 ER PT J AU Zheng, YH Lui, ATY Fok, MC AF Zheng, Yihua Lui, Anthony T. Y. Fok, Mei-Ching TI Viewing perspective in energetic neutral atom intensity SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID TRANSPOLAR POTENTIAL SATURATION; RING CURRENT; GEOMAGNETIC STORMS; ION COMPOSITION; HILL MODEL; IMAGE; MAGNETOSPHERE; CONDUCTIVITY; SIMULATIONS; PARTICLES AB Through interspacecraft comparison of energetic neutral oxygen (ENO) intensity from two different vantage points provided by IMAGE and Geotail, Lui et al. (2005) showed that viewing perspective plays a very important role in the observed ENO intensity level during a magnetic storm period. Motivated by the findings of Lui et al. (2005), we investigate how viewing perspective influences energetic neutral atom emissions from a modeling perspective. The main results of this paper are that (1) our simulation results, based upon O+ ion fluxes from the Comprehensive Ring Current Model and the subsequent ENO calculation, reproduce the total differential ENO intensity obtained from two spacecraft to a reasonable degree and (2) further analysis of our results indicates that pitch angle anisotropy in ring current ion flux, a crucial physical quantity in ring current dynamics, is one major contributor to the difference in energetic neutral atom intensity from different viewing perspectives. C1 [Zheng, Yihua; Lui, Anthony T. Y.] Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. [Fok, Mei-Ching] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Zheng, YH (reprint author), Johns Hopkins Univ, Appl Phys Lab, 11100 Johns Hopkins Rd, Laurel, MD 20723 USA. EM Yihua.Zheng@jhuapl.edu; Tony.lui@jhuapl.edu; mei-ching.h.fok@nasa.gov RI Zheng, Yihua/D-7368-2012; Fok, Mei-Ching/D-1626-2012 FU JHU/APL [NNX07AG08G] FX The constructive comments from both reviewers are greatly appreciated. We thank all team members of Geotail and IMAGE for making both missions a success. We are grateful to D. G. Mitchell and P. C: son Brandt for the provision of IMAGE/HENA data. We want to acknowledge R. A. Wolf and his coworkers for their contribution in the development of RCM. This work was supported by the NASA grants NNX07AG08G to JHU/APL. NR 40 TC 6 Z9 6 U1 0 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 SEP 12 PY 2008 VL 113 IS A9 AR A09217 DI 10.1029/2008JA013070 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 348IK UT WOS:000259204000001 ER PT J AU Harris, R Johnson, MW Han, S Berkley, AJ Johansson, J Bunyk, P Ladizinsky, E Govorkov, S Thom, MC Uchaikin, S Bumble, B Fung, A Kaul, A Kleinsasser, A Amin, MHS Averin, DV AF Harris, R. Johnson, M. W. Han, S. Berkley, A. J. Johansson, J. Bunyk, P. Ladizinsky, E. Govorkov, S. Thom, M. C. Uchaikin, S. Bumble, B. Fung, A. Kaul, A. Kleinsasser, A. Amin, M. H. S. Averin, D. V. TI Probing noise in flux qubits via macroscopic resonant tunneling SO PHYSICAL REVIEW LETTERS LA English DT Article ID QUANTUM; STATES AB Macroscopic resonant tunneling between the two lowest lying states of a bistable rf SQUID is used to characterize noise in a flux qubit. Measurements of the incoherent decay rate as a function of flux bias revealed a Gaussian-shaped profile that is not peaked at the resonance point but is shifted to a bias at which the initial well is higher than the target well. The rms amplitude of the noise, which is proportional to the dephasing rate 1/tau(phi), was observed to be weakly dependent on temperature below 70 mK. Analysis of these results indicates that the dominant source of low energy flux noise in this device is a quantum mechanical environment in thermal equilibrium. C1 [Harris, R.; Johnson, M. W.; Berkley, A. J.; Johansson, J.; Bunyk, P.; Ladizinsky, E.; Govorkov, S.; Thom, M. C.; Uchaikin, S.; Amin, M. H. S.] D Wave Syst Inc, Burnaby, BC V5C 6G9, Canada. [Han, S.] Univ Kansas, Dept Phys & Astron, Lawrence, KS 66045 USA. [Bumble, B.; Fung, A.; Kaul, A.; Kleinsasser, A.] CALTECH, Jet Prop Lab, Pasadena, CA USA. [Averin, D. V.] SUNY Stony Brook, Dept Phys & Astron, Stony Brook, NY 11794 USA. RP Harris, R (reprint author), D Wave Syst Inc, 100-4401 Still Creek Dr, Burnaby, BC V5C 6G9, Canada. EM rharris@dwavesys.com RI Johansson, Jan/G-9005-2012 FU NSF [DMR-0325551] FX We thank J. Hilton, G. Rose, C. J. S. Truncik, A. Tcaciuc, and F. Cioata. Samples were fabricated by the Microelectronics Laboratory of the Jet Propulsion Laboratory, operated by the California Institute of Technology under a contract with NASA. S. H. was supported in part by NSF Grant No. DMR-0325551. NR 26 TC 41 Z9 43 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 SEP 12 PY 2008 VL 101 IS 11 AR 117003 DI 10.1103/PhysRevLett.101.117003 PG 4 WC Physics, Multidisciplinary SC Physics GA 348CN UT WOS:000259188700053 PM 18851318 ER PT J AU Coddington, O Schmidt, KS Pilewskie, P Gore, WJ Bergstrom, RW Roman, M Redemann, J Russell, PB Liu, JC Schaaf, CC AF Coddington, Odele Schmidt, K. Sebastian Pilewskie, Peter Gore, Warren J. Bergstrom, Robert W. Roman, Miguel Redemann, Jens Russell, Philip B. Liu, Jicheng Schaaf, Crystal C. TI Aircraft measurements of spectral surface albedo and its consistency with ground-based and space-borne observations SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID AEROSOL OPTICAL-PROPERTIES; SKY RADIANCE MEASUREMENTS; RADIATIVE-TRANSFER; WATER-VAPOR; REFLECTANCE; ALGORITHM; LAND; SUN; SCATTERING; RETRIEVAL AB Spectral surface albedo, a boundary condition which needs to be accurately known for aerosol remote sensing, surface aerosol forcing, and radiative transfer calculations, also strongly affects Earth's radiation balance. The difficulty in deriving surface albedo from space and aircraft observations lies mainly in the atmospheric correction, especially in aerosol-burdened regions. Because of the different scales, comparing satellite retrievals with airborne or ground-based observations is not straightforward. We use Solar Spectral Flux Radiometer (SSFR) measurements of upward and downward irradiance from aircraft altitude during Megacity Initiative: Local and Global Research Observations (MILAGRO) to determine spectral surface albedo at ground stations and along the flight track (over the wavelength range 350 to 2100 nm), thereby linking flight-level retrieved measurements to larger-scale satellite observations in the polluted Mexico City environment. Our approach involves iteratively adjusting the surface albedo input of a SSFR specific radiative transfer model until the modeled upward irradiance matches the SSFR measurements at flight level. A sensitivity analysis of surface albedo to aerosol optical properties provides a retrieval uncertainty, which can outweigh the SSFR instrument uncertainty under highly variable conditions (or uncertain measurements) of aerosol optical depth and asymmetry parameter. Comparisons between spectral surface albedo derived from the SSFR, Multi-Filter Rotating Shadowband Radiometer, and the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument onboard the NASA-EOS Terra and Aqua satellites are shown with differences of 6-10% and 0.025-0.05 units, respectively. Along-track comparisons between the SSFR and MODIS show that two instruments (aircraft and satellite) can capture inhomogeneous surface albedo scene changes. C1 [Coddington, Odele; Schmidt, K. Sebastian; Pilewskie, Peter] Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80309 USA. [Bergstrom, Robert W.] Bay Area Environm Res Inst, Sonoma, CA 95476 USA. [Gore, Warren J.; Russell, Philip B.] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. [Roman, Miguel; Liu, Jicheng; Schaaf, Crystal C.] Boston Univ, Ctr Remote Sensing, Boston, MA 02215 USA. [Roman, Miguel; Liu, Jicheng; Schaaf, Crystal C.] Boston Univ, Dept Geog, Boston, MA 02215 USA. [Redemann, Jens] Bay Area Environm Res Inst, Ventura, CA 93003 USA. RP Coddington, O (reprint author), Univ Colorado, Atmospher & Space Phys Lab, Campus Box 392, Boulder, CO 80309 USA. EM odele.coddington@lasp.colorado.edu RI Coddington, Odele/F-6342-2012; SCHMIDT, KONRAD SEBASTIAN/C-1258-2013; Liu, Jicheng/B-4575-2009; Roman, Miguel/D-4764-2012 OI Coddington, Odele/0000-0002-4338-7028; SCHMIDT, KONRAD SEBASTIAN/0000-0003-3899-228X; Roman, Miguel/0000-0003-3953-319X NR 31 TC 28 Z9 28 U1 2 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 SEP 11 PY 2008 VL 113 IS D17 AR D17209 DI 10.1029/2008JD010089 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 348HB UT WOS:000259200500002 ER PT J AU Seelos, KD Arvidson, RE Cull, SC Hash, CD Heet, TL Guinness, EA McGuire, PC Morris, RV Murchie, SL Parker, TJ Roush, TL Seelos, FP Wolff, MJ AF Seelos, K. D. Arvidson, R. E. Cull, S. C. Hash, C. D. Heet, T. L. Guinness, E. A. McGuire, P. C. Morris, R. V. Murchie, S. L. Parker, T. J. Roush, T. L. Seelos, F. P. Wolff, M. J. TI Geomorphologic and mineralogic characterization of the northern plains of Mars at the Phoenix Mission candidate landing sites SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID GUSEV CRATER; SPIRIT ROVER; NEAR-SURFACE; ICE; ULTRAVIOLET; CHEMISTRY; VIKING AB A suite of remote sensing data is used to evaluate both geomorphology and mineralogy of the candidate landing sites for the 2007 Phoenix Mission. Three candidate landing site boxes are situated in the northern plains of Mars on the distal flank of Alba Patera in the region from 67 degrees N to 72 degrees N and from similar to 230 degrees E to 260 degrees E. Geomorphology is mapped at subkilometer spatial scales using Thermal Emission Imaging System (THEMIS) visible and Mars Orbiter Laser Altimeter (MOLA) topographic data, supplemented by images from the High-Resolution Imaging Science Experiment (HiRISE) and Context Imager (CTX). Mineralogy and spectral properties are examined using Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) visible and near-infrared multispectral mapping and targeted hyperspectral data at similar to 200 and similar to 20 m/pixel, respectively. Geomorphic mapping supports the idea that terrains along the boundary between the Amazonian Scandia region and Vastitas Borealis marginal geologic units have undergone extensive modification. Intercrater plains are disrupted to form mesas and interlocking blocks, while irregular depressions and knobby terrain are consistent with erosion/subsidence and local deposition. Despite the varied morphology, the present-day surface is nearly homogeneous with spectral signatures dominated by nanophase iron oxides and basaltic sand and rocks, similar to that of the Gusev crater plains at the Mars Exploration Rover (MER) landing site. The compilation of geomorphic and spectral information for the candidate Phoenix landing sites provides a framework for the mission's in situ observations to be extrapolated to the northern plains as a whole. C1 [Seelos, K. D.; Murchie, S. L.; Seelos, F. P.] Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. [Arvidson, R. E.; Cull, S. C.; Heet, T. L.; Guinness, E. A.; McGuire, P. C.] Washington Univ, Dept Earth & Planetary Sci, St Louis, MO 63130 USA. [Hash, C. D.] Appl Coherent Technol Corp, Herndon, VA USA. [Morris, R. V.] NASA, Lyndon B Johnson Space Ctr, ARES Code KR, Houston, TX 77058 USA. [Parker, T. J.] NASA, Jet Prop Lab, Pasadena, CA 91109 USA. [Roush, T. L.] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. [Wolff, M. J.] Space Sci Inst, Brookfield, WI 53045 USA. RP Seelos, KD (reprint author), Johns Hopkins Univ, Appl Phys Lab, MP3-E140,11100 Johns Hopkins Rd, Laurel, MD 20723 USA. EM kim.seelos@jhuapl.edu; arvidson@rsmail.wustl.edu; selbycull@gmail.com; chash@actgate.com; tlheet@artsci.wustl.edu; guinness@rsmail.wustl.edu; mcguire@epsci.wustl.edu; richard.v.morris@nasa.gov; scott.murchie@jhuapl.edu; timothy.j.parker@jpl.nasa.gov; ted.l.roush@nasa.gov; frank.seelos@jhuapl.edu; wolff@spacescience.org RI Seelos, Frank/C-7875-2016; McGuire, Patrick/D-2962-2013; Murchie, Scott/E-8030-2015; Seelos, Kimberly/F-4647-2015 OI Seelos, Frank/0000-0001-9721-941X; McGuire, Patrick/0000-0001-6592-4966; Murchie, Scott/0000-0002-1616-8751; Seelos, Kimberly/0000-0001-7236-0580 FU NASA; CRISM; HiRISE; CTX; THEMIS; MOC FX This research was supported by NASA through the Phoenix and MRO/CRISM Missions. Many thanks are due to the CRISM, HiRISE, CTX, THEMIS, and MOC instrument teams for their continued support of the Phoenix landing site characterization effort. The authors would also like to thank J. Skinner and K. Tanaka for thoughtful review and discussion. NR 63 TC 19 Z9 19 U1 1 U2 10 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 SEP 11 PY 2008 VL 113 AR E00A13 DI 10.1029/2008JE003088 PG 16 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 348HQ UT WOS:000259202000001 ER PT J AU Fang, XH Randall, CE Lummerzheim, D Solomon, SC Mills, MJ Marsh, DR Jackman, CH Wang, WB Lu, G AF Fang, Xiaohua Randall, Cora E. Lummerzheim, Dirk Solomon, Stanley C. Mills, Michael J. Marsh, Daniel R. Jackman, Charles H. Wang, Wenbin Lu, Gang TI Electron impact ionization: A new parameterization for 100 eV to 1 MeV electrons SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID THERMOSPHERE; ATMOSPHERE; TRANSPORT; MODEL; PRECIPITATION; IONOSPHERE; MESOSPHERE; MIDDLE AB We present a new parameterization of the altitude profile of the ionization rate in the Earth's atmosphere due to precipitating energetic electrons. Precipitating electrons are assumed to have a Maxwellian energy distribution and an isotropic pitch angle distribution above the atmosphere. In this study, two electron transport models (whose validity has been verified by observations) are employed to calculate the ionization rate, to which we have fit our new parameterization. To derive a new parameterization, we follow a similar scheme to that of Roble and Ridley (1987) but take into account further functional dependence on the incident electron energy. As a result, the new method presented in this paper provides a highly improved prediction for electron impact in a significantly extended energy range from 100 eV to 1 MeV, spanning 4 orders of magnitude. Note that we have neglected the contribution of bremsstrahlung X rays generated by energetic electrons, which are mostly important below 50 km altitude. The comparison of parameterization results with model calculations shows that the errors generally fall well within +/- 5% in both the altitude-integrated total ionization rate and the peak value. The altitude profile as a whole is also accurately predicted, with errors in the altitudes of the peak and e-folding ionization rates significantly less than 5 km. The proposed new parameterization method with high accuracy is thus ready to be implemented into global models to assess the electron impact on the ionosphere and the atmosphere. C1 [Fang, Xiaohua; Randall, Cora E.; Mills, Michael J.] Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80309 USA. [Jackman, Charles H.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Solomon, Stanley C.; Wang, Wenbin; Lu, Gang] Natl Ctr Atmospher Res, High Altitude Observ, Boulder, CO 80301 USA. [Lummerzheim, Dirk] Univ Alaska Fairbanks, Inst Geophys, Fairbanks, AK 99775 USA. [Marsh, Daniel R.] Natl Ctr Atmospher Res, Boulder, CO 80307 USA. RP Fang, XH (reprint author), Univ Colorado, Atmospher & Space Phys Lab, Campus Box 392, Boulder, CO 80309 USA. EM xiaohua.fang@lasp.colorado.edu RI Lu, Gang/A-6669-2011; Fang, Xiaohua/C-2773-2008; Jackman, Charles/D-4699-2012; Solomon, Stanley/J-4847-2012; Wang, Wenbin/G-2596-2013; Marsh, Daniel/A-8406-2008; Randall, Cora/L-8760-2014 OI Fang, Xiaohua/0000-0002-6584-2837; Solomon, Stanley/0000-0002-5291-3034; Wang, Wenbin/0000-0002-6287-4542; Marsh, Daniel/0000-0001-6699-494X; Randall, Cora/0000-0002-4313-4397 FU NASA LWS [NNX06AC05G] FX The work at the University of Colorado was supported by NASA LWS grant NNX06AC05G. The work at the National Center for Atmospheric Research is sponsored by the National Science Foundation. NR 18 TC 27 Z9 27 U1 3 U2 6 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 SEP 11 PY 2008 VL 113 IS A9 AR A09311 DI 10.1029/2008JA013384 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 348IJ UT WOS:000259203900005 ER PT J AU Bendo, GJ Draine, BT Engelbracht, CW Helou, G Thornley, MD Bot, C Buckalew, BA Calzetti, D Dale, DA Hollenbach, J Li, A Moustakas, J AF Bendo, G. J. Draine, B. T. Engelbracht, C. W. Helou, G. Thornley, M. D. Bot, C. Buckalew, B. A. Calzetti, D. Dale, D. A. Hollenbach, J. Li, A. Moustakas, J. TI The relations among 8, 24 and 160 mu m dust emission within nearby spiral galaxies SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE galaxies : ISM; infrared : galaxies ID SPECTRAL ENERGY-DISTRIBUTION; SPITZER-SPACE-TELESCOPE; INFRARED ARRAY CAMERA; STAR-FORMING GALAXIES; H-II REGIONS; INTERSTELLAR DUST; HII-REGIONS; ABUNDANCE GRADIENTS; GLOBAL PROPERTIES; OXYGEN ABUNDANCE AB We investigate the relations among the stellar continuum-subtracted 8 mu m polycyclic aromatic hydrocarbon (PAH 8 mu m) emission, 24 mu m hot dust emission and 160 mu m cold dust emission in 15 nearby face-on spiral galaxies in the Spitzer Infrared Nearby Galaxies Survey sample. The relation between PAH 8 and 24 mu m emission measured in similar to 2 kpc regions is found to exhibit a significant amount of scatter, and strong spatial variations are observed in the (PAH 8 mu m)/24 mu m surface brightness ratio. In particular, the (PAH 8 mu m)/24 mu m surface brightness ratio is observed to be high in the diffuse interstellar medium and low in bright star-forming regions and other locations with high 24 mu m surface brightness. PAH 8 mu m emission is found to be well-correlated with 160 mu m emission on spatial scales of similar to 2 kpc, and the (PAH 8 mu m)/160 mu m surface brightness ratio is generally observed to increase as the 160 mu m surface brightness increases. These results suggest that the PAHs are associated with the diffuse, cold dust that produces most of the 160 mu m emission in these galaxies, and the variations in the (PAH 8 mu m)/160 mu m ratio may generally be indicative of either the intensity or the spectrum of the interstellar radiation field that is heating both the PAHs and the diffuse interstellar dust. C1 [Bendo, G. J.] Univ London Imperial Coll Sci Technol & Med, Astrophys Grp, London SW7 2AZ, England. [Draine, B. T.] Princeton Univ Observ, Princeton, NJ 08544 USA. [Engelbracht, C. W.] Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. [Bot, C.] CALTECH, Spitzer Sci Ctr, Pasadena, CA 91101 USA. [Thornley, M. D.] Bucknell Univ, Dept Phys & Astron, Lewisburg, PA 17837 USA. [Buckalew, B. A.] Embry Riddle Aeronaut Univ, Dept Phys, Prescott, AZ 86301 USA. [Calzetti, D.] Univ Massachusetts, Dept Astron, Amherst, MA 01002 USA. [Dale, D. A.] Univ Wyoming, Dept Phys & Astron, Laramie, WY 82071 USA. [Hollenbach, J.] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. [Li, A.] Univ Missouri, Dept Phys & Astron, Columbia, MO 65211 USA. [Moustakas, J.] NYU, Dept Phys, New York, NY 10003 USA. RP Bendo, GJ (reprint author), Univ London Imperial Coll Sci Technol & Med, Astrophys Grp, London SW7 2AZ, England. EM g.bendo@imperial.ac.uk OI Bot, Caroline/0000-0001-6118-2985 FU STFC; NSF [AST04-06883, AST 07-07866]; Spitzer Theory Programs FX This work was funded by STFC. BTD was supported in part by NSF grant AST04-06883. AL is supported in part by the Spitzer Theory Programs and NSF grant AST 07-07866. NR 59 TC 72 Z9 72 U1 0 U2 1 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD SEP 11 PY 2008 VL 389 IS 2 BP 629 EP 650 DI 10.1111/j.1365-2966.2008.13567.x PG 22 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 347NW UT WOS:000259149300007 ER PT J AU Keenan, FP Jess, DB Aggarwal, KM Thomas, RJ Brosius, JW Davila, JM AF Keenan, F. P. Jess, D. B. Aggarwal, K. M. Thomas, R. J. Brosius, J. W. Davila, J. M. TI Emission lines of Fe X in active region spectra obtained with the Solar Extreme-ultraviolet Research Telescope and Spectrograph SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE atomic data; Sun : activity; Sun : corona ID ATOMIC DATA; RATE COEFFICIENTS; CORONAL LINES; NI-XII; TRANSITIONS; IONS; EXCITATION; STRENGTHS; SERTS; IRON AB Fully relativistic calculations of radiative rates and electron impact excitation cross-sections for Fe X are used to derive theoretical emission-line ratios involving transitions in the 174-366 angstrom wavelength range. A comparison of these with solar active region observations obtained during the 1989 and 1995 flights of the Solar Extreme-ultraviolet Research Telescope and Spectrograph (SERTS) reveals generally very good agreement between theory and experiment. Several Fe X emission features are detected for the first time in SERTS spectra, while the 3s(2)3p(5) (2)P(3/2)-3s(2)3p(4)((1)S)3d (2)D(3/2) transition at 195.32 angstrom is identified for the first time (to our knowledge) in an astronomical source. The most useful Fe X electron density (N(e)) diagnostic line ratios are assessed to be 175.27/174.53 and 175.27/177.24, which both involve lines close in wavelength and free from blends, vary by factors of 13 between N(e) = 10(8) and 10(11) cm(-3), and yet show little temperature sensitivity. Should these lines not be available, then the 257.25/345.74 ratio may be employed to determine N(e), although this requires an accurate evaluation of the instrument intensity calibration over a relatively large wavelength range. However, if the weak 324.73 angstrom line of Fe X is reliably detected, the use of 324.73/345.74 or 257.25/324.73 is recommended over 257.25/345.74. Electron densities deduced from 175.27/174.53 and 175.27/177.24 for the stars Procyon and alpha Cen, using observations from the Extreme-Ultraviolet Explorer (EUVE) satellite, are found to be consistent and in agreement with the values of N(e) determined from other diagnostic ratios in the EUVE spectra. A comparison of several theoretical extreme-ultraviolet Fe X line ratios with experimental values for a theta-pinch, for which the plasma parameters have been independently determined, reveals reasonable agreement between theory and observation, providing some independent support for the accuracy of the adopted atomic data. C1 [Keenan, F. P.; Jess, D. B.; Aggarwal, K. M.] Queens Univ Belfast, Sch Math & Phys, Astrophys Res Ctr, Belfast BT7 1NN, Antrim, North Ireland. [Thomas, R. J.; Brosius, J. W.; Davila, J. M.] NASA, Goddard Space Flight Ctr, Heliophys Sci Div, Lab Solar Phys, Greenbelt, MD 20771 USA. [Brosius, J. W.] Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA. RP Keenan, FP (reprint author), Queens Univ Belfast, Sch Math & Phys, Astrophys Res Ctr, Belfast BT7 1NN, Antrim, North Ireland. EM F.Keenan@qub.ac.uk OI Jess, David/0000-0002-9155-8039 FU EPSRC; Department of Education and Learning (Northern Ireland); NASA's Goddard Space Flight Centre; Solar Physics Office of NASA's Space Physics Division; NASA [NAG5-13321]; William Penney Fellowship FX KMA acknowledges financial support from EPSRC, while DBJ is grateful to the Department of Education and Learning (Northern Ireland) and NASA's Goddard Space Flight Centre for the award of a studentship. The SERTS rocket programme is supported by RTOP grants from the Solar Physics Office of NASA's Space Physics Division. JWB acknowledges additional NASA support under grant NAG5-13321. FPK is grateful to AWE Aldermaston for the award of a William Penney Fellowship. The authors thank Peter van Hoof for the use of his Atomic Line List. CHIANTI is a collaborative project involving the Naval Research Laboratory (USA), Rutherford Appleton Laboratory (UK) and the Universities of Florence (Italy) and Cambridge (UK). NR 38 TC 6 Z9 6 U1 0 U2 1 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD SEP 11 PY 2008 VL 389 IS 2 BP 939 EP 948 DI 10.1111/j.1365-2966.2008.13615.x PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 347NW UT WOS:000259149300031 ER PT J AU Pastorello, A Kasliwal, MM Crockett, RM Valenti, S Arbour, R Itagaki, K Kaspi, S Gal-Yam, A Smartt, SJ Griffith, R Maguire, K Ofek, EO Seymour, N Stern, D Wiethoff, W AF Pastorello, A. Kasliwal, M. M. Crockett, R. M. Valenti, S. Arbour, R. Itagaki, K. Kaspi, S. Gal-Yam, A. Smartt, S. J. Griffith, R. Maguire, K. Ofek, E. O. Seymour, N. Stern, D. Wiethoff, W. TI The Type IIb SN 2008ax: spectral and light curve evolution SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE supernovae : general; supernovae : individual; SN 2008ax; supernovae : individual; SN 1993J; galaxies : individual; NGC 4490 ID GAMMA-RAY BURST; SUPERNOVA 1993J; OPTICAL PHOTOMETRY; IB/C SUPERNOVAE; BINARY-SYSTEM; SN 2002AP; PROGENITOR; GALAXIES; SPECTROSCOPY; STAR AB We present spectroscopy and photometry of the He-rich supernova (SN) 2008ax. The early-time spectra show prominent P-Cygni H lines, which decrease with time and disappear completely about 2 months after the explosion. In the same period He I lines become the most prominent spectral features. SN 2008ax displays the ordinary spectral evolution of a Type IIb supernova. A stringent pre-discovery limit constrains the time of the shock breakout of SN 2008ax to within only a few hours. Its light curve, which peaks in the B band about 20 d after the explosion, strongly resembles that of other He-rich core-collapse supernovae. The observed evolution of SN 2008ax is consistent with the explosion of a young Wolf-Rayet (of WNL type) star, which had retained a thin, low-mass shell of its original H envelope. The overall characteristics of SN 2008ax are reminiscent of those of SN 1993J, except for a likely smaller H mass. This may account for the findings that the progenitor of SN 2008ax was a WNL star and not a K supergiant as in the case of SN 1993J, that a prominent early-time peak is missing in the light curve of SN 2008ax, and that H alpha is observed at higher velocities in SN 2008ax than in SN 1993J. C1 [Pastorello, A.; Crockett, R. M.; Valenti, S.; Smartt, S. J.; Maguire, K.] Queens Univ Belfast, Sch Math & Phys, Astrophys Res Ctr, Belfast BT7 1NN, Antrim, North Ireland. [Kasliwal, M. M.; Ofek, E. O.] CALTECH, Div Phys Math & Astron, Pasadena, CA 91125 USA. [Arbour, R.] Pennell Observ, S Wonston SO21 3HE, Hants, England. [Itagaki, K.] Itagaki Astron Observ, Teppo, Yamagata 9902492, Japan. [Kaspi, S.] Tel Aviv Univ, Raymond & Beverly Sackler Fac Exact Sci, Wise Observ, IL-69978 Tel Aviv, Israel. [Kaspi, S.] Tel Aviv Univ, Sch Phys & Astron, IL-69978 Tel Aviv, Israel. [Kaspi, S.] Technion Israel Inst Technol, Dept Phys, IL-32000 Haifa, Israel. [Gal-Yam, A.] Weizmann Inst Sci, Benoziyo Ctr Astrophys, IL-76100 Rehovot, Israel. [Griffith, R.] Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. [Griffith, R.; Stern, D.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Seymour, N.] CALTECH, Spitzer Sci Ctr, Pasadena, CA 91125 USA. RP Pastorello, A (reprint author), Queens Univ Belfast, Sch Math & Phys, Astrophys Res Ctr, Belfast BT7 1NN, Antrim, North Ireland. EM a.pastorello@qub.ac.uk OI Seymour, Nicholas/0000-0003-3506-5536 FU UK Science and Technology Facilities Council; European Heads of Research Councils; European Science Foundation EURYI; Leverhulme Trust; NASA; Weizmann Institute of Science FX This manuscript is partly based on observations collected at the Hale Telescope, Palomar Observatory, as part of a collaborative agreement between the California Institute of Technology, its divisions Caltech Optical Observatories and the Jet Propulsion Laboratory (operated for NASA), and Cornell University. The paper is also based on observations obtained at the 60-inch Telescope of the Palomar Observatory and 2-m Liverpool Telescope. The Liverpool Telescope is operated on the island of La Palma by Liverpool John Moores University in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias with financial support from the UK Science and Technology Facilities Council. We thank John Dann of the Wise Observatory staff for his expert assistance with the observations. This work, conducted as part of the award 'Understanding the lives of massive stars from birth to supernovae' (SJS) made under the European Heads of Research Councils and European Science Foundation EURYI (European Young Investigator) Awards scheme, was supported by funds from the Participating Organisations of EURYI and the EC Sixth Framework Programme. SJS also thanks the Leverhulme Trust for funding through the Philip Leverhulme Prize scheme. The work of DS was carried out at Jet Propulsion Laboratory, California Institute of Technology, under a contract with NASA. AG acknowledges the Benoziyo Center for Astrophysics and the William Z. and Eda Bess Novick New Scientists Fund at the Weizmann Institute of Science. We acknowledge the usage of the HyperLeda data base (http://leda.univ-lyon1.fr). NR 85 TC 68 Z9 68 U1 0 U2 2 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 SEP 11 PY 2008 VL 389 IS 2 BP 955 EP 966 DI 10.1111/j.1365-2966.2008.13618.x PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 347NW UT WOS:000259149300033 ER PT J AU Racusin, JL Karpov, SV Sokolowski, M Granot, J Wu, XF Pal'shin, V Covino, S van der Horst, AJ Oates, SR Schady, P Smith, RJ Cummings, J Starling, RLC Piotrowski, LW Zhang, B Evans, PA Holland, ST Malek, K Page, MT Vetere, L Margutti, R Guidorzi, C Kamble, AP Curran, PA Beardmore, A Kouveliotou, C Mankiewicz, L Melandri, A O'Brien, PT Page, KL Piran, T Tanvir, NR Wrochna, G Aptekar, RL Barthelmy, S Bartolini, C Beskin, GM Bondar, S Bremer, M Campana, S Castro-Tirado, A Cucchiara, A Cwiok, M D'Avanzo, P D'Elia, V Della Valle, M Postigo, AD Dominik, W Falcone, A Fiore, F Fox, DB Frederiks, DD Fruchter, AS Fugazza, D Garrett, MA Gehrels, N Golenetskii, S Gomboc, A Gorosabel, J Greco, G Guarnieri, A Immler, S Jelinek, M Kasprowicz, G La Parola, V Levan, AJ Mangano, V Mazets, EP Molinari, E Moretti, A Nawrocki, K Oleynik, PP Osborne, JP Pagani, C Pandey, SB Paragi, Z Perri, M Piccioni, A Ramirez-Ruiz, E Roming, PWA Steele, IA Strom, RG Testa, V Tosti, G Ulanov, MV Wiersema, K Wijers, RAMJ Winters, JM Zarnecki, AF Zerbi, F Meszaros, P Chincarini, G Burrows, DN AF Racusin, J. L. Karpov, S. V. Sokolowski, M. Granot, J. Wu, X. F. Pal'shin, V. Covino, S. van der Horst, A. J. Oates, S. R. Schady, P. Smith, R. J. Cummings, J. Starling, R. L. C. Piotrowski, L. W. Zhang, B. Evans, P. A. Holland, S. T. Malek, K. Page, M. T. Vetere, L. Margutti, R. Guidorzi, C. Kamble, A. P. Curran, P. A. Beardmore, A. Kouveliotou, C. Mankiewicz, L. Melandri, A. O'Brien, P. T. Page, K. L. Piran, T. Tanvir, N. R. Wrochna, G. Aptekar, R. L. Barthelmy, S. Bartolini, C. Beskin, G. M. Bondar, S. Bremer, M. Campana, S. Castro-Tirado, A. Cucchiara, A. Cwiok, M. D'Avanzo, P. D'Elia, V. Della Valle, M. de Ugarte Postigo, A. Dominik, W. Falcone, A. Fiore, F. Fox, D. B. Frederiks, D. D. Fruchter, A. S. Fugazza, D. Garrett, M. A. Gehrels, N. Golenetskii, S. Gomboc, A. Gorosabel, J. Greco, G. Guarnieri, A. Immler, S. Jelinek, M. Kasprowicz, G. La Parola, V. Levan, A. J. Mangano, V. Mazets, E. P. Molinari, E. Moretti, A. Nawrocki, K. Oleynik, P. P. Osborne, J. P. Pagani, C. Pandey, S. B. Paragi, Z. Perri, M. Piccioni, A. Ramirez-Ruiz, E. Roming, P. W. A. Steele, I. A. Strom, R. G. Testa, V. Tosti, G. Ulanov, M. V. Wiersema, K. Wijers, R. A. M. J. Winters, J. M. Zarnecki, A. F. Zerbi, F. Meszaros, P. Chincarini, G. Burrows, D. N. TI Broadband observations of the naked-eye gamma-ray burst GRB 080319B SO NATURE LA English DT Article ID AFTERGLOW EMISSION; OPTICAL-EMISSION; 2-COMPONENT JET; FIREBALL MODEL; REVERSE SHOCK; LIGHT CURVES; GRB 990123; TELESCOPE; SPECTRA; FLASH AB Long- duration gamma-ray bursts ( GRBs) release copious amounts of energy across the entire electromagnetic spectrum, and so provide a window into the process of black hole formation from the collapse of massive stars. Previous early optical observations of even the most exceptional GRBs ( 990123 and 030329) lacked both the temporal resolution to probe the optical flash in detail and the accuracy needed to trace the transition from the prompt emission within the outflow to external shocks caused by interaction with the progenitor environment. Here we report observations of the extraordinarily bright prompt optical and gamma-ray emission of GRB 080319B that provide diagnostics within seconds of its formation, followed by broadband observations of the afterglow decay that continued for weeks. We show that the prompt emission stems from a single physical region, implying an extremely relativistic outflow that propagates within the narrow inner core of a two- component jet. C1 [Racusin, J. L.; Wu, X. F.; Vetere, L.; Cucchiara, A.; Falcone, A.; Fox, D. B.; Pagani, C.; Roming, P. W. A.; Meszaros, P.; Burrows, D. N.] Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA. [Karpov, S. V.; Beskin, G. M.] Russian Acad Sci, Special Astrophys Observ, Nizhnii Arkhyz 369167, Russia. [Sokolowski, M.; Wrochna, G.; Nawrocki, K.] Soltan Inst Nucl Studies, PL-05400 Otwock, Poland. [Granot, J.] Univ Hertfordshire, Ctr Astrophys Res, Hatfield AL10 9AB, Herts, England. [Wu, X. F.] Chinese Acad Sci, Purple Mt Observ, Nanjing 210008, Peoples R China. [Pal'shin, V.; Aptekar, R. L.; Frederiks, D. D.; Golenetskii, S.; Mazets, E. P.; Oleynik, P. P.; Ulanov, M. V.] AF Ioffe Phys Tech Inst, Expt Astrophys Lab, St Petersburg 194021, Russia. [Covino, S.; Guidorzi, C.; Campana, S.; D'Avanzo, P.; Fugazza, D.; Molinari, E.; Moretti, A.; Zerbi, F.; Chincarini, G.] INAF Osserv Astron Brera, I-23807 Merate, LC, Italy. [Oates, S. R.; Schady, P.; Page, M. T.] UCL, Mullard Space Sci Lab, Dorking RH5 6NT, Surrey, England. [Smith, R. J.; Guidorzi, C.; Melandri, A.; Steele, I. A.] Liverpool John Moores Univ, Astrophys Res Inst, Birkenhead CH41 1LD, Merseyside, England. [Cummings, J.; Barthelmy, S.; Gehrels, N.] NASA, Goddard Space Flight Ctr, Astrophys Sci Div, Greenbelt, MD 20771 USA. [Starling, R. L. C.; Evans, P. A.; Beardmore, A.; O'Brien, P. T.; Page, K. L.; Tanvir, N. R.; Osborne, J. P.; Wiersema, K.] Univ Leicester, Dept Phys & Astron, Leicester LE1 7RH, Leics, England. [Piotrowski, L. W.; Cwiok, M.; Dominik, W.; Zarnecki, A. F.] Univ Warsaw, Inst Expt Phys, PL-00681 Warsaw, Poland. [Zhang, B.] Univ Nevada, Dept Phys & Astron, Las Vegas, NV 89154 USA. [Holland, S. T.; Immler, S.] NASA, Goddard Space Flight Ctr, Astrophys Sci Div, Greenbelt, MD 20771 USA. [Holland, S. T.] Univ Space Res Assoc, Columbia, MD 21044 USA. [Holland, S. T.; Immler, S.] NASA, Goddard Space Flight Ctr, Ctr Res & Explorat Space Sci & Technol, Greenbelt, MD 20771 USA. [Malek, K.; Mankiewicz, L.] Polish Acad Sci, Ctr Theoret Phys, PL-02668 Warsaw, Poland. [Margutti, R.; Chincarini, G.] Univ Milano Bicocca, Dept Phys, I-20126 Milan, Italy. [Kamble, A. P.; Curran, P. A.; Strom, R. G.; Wijers, R. A. M. J.] Univ Amsterdam, Astron Inst Anton Pannekoek, NL-1098 SJ Amsterdam, Netherlands. [Kouveliotou, C.] NASA, George C Marshall Space Flight Ctr, NSSTC, Huntsville, AL 35805 USA. [Piran, T.] Hebrew Univ Jerusalem, Racah Inst Phys, IL-91904 Jerusalem, Israel. [Bartolini, C.; Greco, G.; Guarnieri, A.; Piccioni, A.] Univ Bologna, I-40126 Bologna, Italy. [Bondar, S.] Inst Precise Instrumentat, Nizhnii Arkhyz 369167, Russia. [Bremer, M.; Winters, J. M.] Inst Radio Astron Millimetr, F-38406 St Martin Dheres, France. [Castro-Tirado, A.; Gorosabel, J.; Jelinek, M.] Inst Astrofis Andalucia, CSIC, E-18080 Granada, Spain. [D'Elia, V.; Fiore, F.; Testa, V.] Osserv Astron Roma, INAF, I-00040 Monte Porzio Catone, Italy. [Della Valle, M.] European So Observ, D-85748 Garching, Germany. [Della Valle, M.] Osserv Astron Capodimonte, INAF, I-80131 Naples, Italy. [de Ugarte Postigo, A.] European So Observ, Santiago 19, Chile. [Fruchter, A. S.] Space Telescope Sci Inst, Baltimore, MD 21218 USA. [Garrett, M. A.; Strom, R. G.] Netherlands Inst Radio Astron ASTRON, NL-7990 AA Dwingeloo, Netherlands. [Garrett, M. A.] Leiden Univ, Leiden Observ, NL-2300 RA Leiden, Netherlands. [Garrett, M. A.] Swinburne Univ Technol, Ctr Astrophys & Supercomp, Hawthorn, Vic 3122, Australia. [Gomboc, A.] Univ Ljubljana, Fac Math & Phys, SI-1000 Ljubljana, Slovenia. [Kasprowicz, G.] Warsaw Univ Technol, Inst Elect Syst, PL-00665 Warsaw, Poland. [La Parola, V.; Mangano, V.] INAF IASF PA, I-90146 Palermo, Italy. [Levan, A. J.] Univ Warwick, Dept Phys, Coventry CV4 7AL, W Midlands, England. [Pandey, S. B.] Aryabhatta Res Inst Observ Sci ARIES, Naini Tal 263129, India. [Paragi, Z.] JIVE, NL-7990 AA Dwingeloo, Netherlands. [Perri, M.] ESRIN, ASI Sci Data Ctr, I-00044 Frascati, Italy. [Ramirez-Ruiz, E.] Univ Calif Santa Cruz, Dept Astron & Astrophys, Santa Cruz, CA 95064 USA. [Tosti, G.] Univ Perugia, I-06100 Perugia, Italy. [Meszaros, P.] Penn State Univ, Dept Phys, Davey Lab 104, University Pk, PA 16801 USA. RP Racusin, JL (reprint author), Penn State Univ, Dept Astron & Astrophys, 525 Davey Lab, University Pk, PA 16802 USA. EM racusin@astro.psu.edu RI Mankiewicz, Lech/G-4171-2011; Malek, Katarzyna/A-1254-2012; Racusin, Judith/D-2935-2012; Pal'shin, Valentin/F-3973-2014; Ulanov, Mikhail/B-3467-2015; Barthelmy, Scott/D-2943-2012; Gehrels, Neil/D-2971-2012; Curran, Peter/B-5293-2013; Sokolowski, Marcin/B-5584-2013; Tosti, Gino/E-9976-2013; Oleynik, Philipp/C-1104-2014; Frederiks, Dmitry/C-7612-2014; Aptekar, Raphail/B-3456-2015; Golenetskii, Sergey/B-3818-2015; Jelinek, Martin/E-5290-2016; Wu, Xuefeng/G-5316-2015; OI Ulanov, Mikhail/0000-0002-0076-5228; Curran, Peter/0000-0003-3003-4626; Sokolowski, Marcin/0000-0001-5772-338X; Wijers, Ralph/0000-0002-3101-1808; D'Elia, Valerio/0000-0002-7320-5862; moretti, alberto/0000-0002-9770-0315; Zerbi, Filippo Maria/0000-0002-9996-973X; Della Valle, Massimo/0000-0003-3142-5020; Jelinek, Martin/0000-0003-3922-7416; Wu, Xuefeng/0000-0002-6299-1263; Molinari, Emilio/0000-0002-1742-7735; Frederiks, Dmitry/0000-0002-1153-6340; Castro-Tirado, A. J./0000-0003-2999-3563 FU NASA; National Science Foundation (NSF); Agenzia Spaziale Italiana, the Ministero dell'Universita` e della Ricerca ( MUR); Ministero degli Affari Esteri, the Netherlands Organization for Scientific Research; National Science Foundation of China; Russian Space Agency; Science and Technology and Facilities Council ( STFC); Slovenian Research Agency; Ministry for Higher Education, Science, and Technology, Slovenia; Polish Ministry of Science and Higher Education FX We thank E. Rol for comments. This research was supported by NASA, the National Science Foundation (NSF), the Agenzia Spaziale Italiana, the Ministero dell'Universita` e della Ricerca ( MUR), the Ministero degli Affari Esteri, the Netherlands Organization for Scientific Research ( NWO), the National Science Foundation of China, the Russian Space Agency, Science and Technology and Facilities Council ( STFC), the Slovenian Research Agency, the Ministry for Higher Education, Science, and Technology, Slovenia, and the Polish Ministry of Science and Higher Education. NR 50 TC 332 Z9 337 U1 1 U2 26 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD SEP 11 PY 2008 VL 455 IS 7210 BP 183 EP 188 DI 10.1038/nature07270 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 346SZ UT WOS:000259090800038 PM 18784718 ER PT J AU Bischoff, C Hyatt, L McMahon, JJ Nixon, GW Samtleben, D Smith, KM Vanderlinde, K Barkats, D Farese, P Gaier, T Gundersen, JO Hedman, MM Staggs, ST Winstein, B AF Bischoff, C. Hyatt, L. McMahon, J. J. Nixon, G. W. Samtleben, D. Smith, K. M. Vanderlinde, K. Barkats, D. Farese, P. Gaier, T. Gundersen, J. O. Hedman, M. M. Staggs, S. T. Winstein, B. TI New measurements of fine-scale CMB polarization power spectra from CAPMAP at both 40 and 90 Ghz SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmic microwave background; cosmology : observations; polarization ID PROBE WMAP OBSERVATIONS; MICROWAVE BACKGROUND-RADIATION; GRAVITY-WAVES; RADIO-SOURCES; ANTENNA; TEMPERATURE AB We present new measurements of the CMB polarization from the final season of CAPMAP. The data set was obtained in winter 2004-2005 with the 7 m antenna in Crawford Hill, New Jersey, from 12W-band (84-100 GHz) and four Q-band (36-45 GHz) correlation polarimeters with 3.30 and 6.50 beam sizes, respectively. After selection criteria were applied, 956 ( 939) hr of data survived for analysis of W- band (Q-band) data. Two independent and complementary pipelines produced results in excellent agreement with each other. A broad suite of null tests, as well as extensive simulations, showed that systematic errors were minimal, and a comparison of the W- band and Q-band sky maps revealed no contamination from galactic foregrounds. We report the E-mode and B-mode power spectra in seven bands in the range 200 less than or similar to l less than or similar to 3000, extending the range of previous measurements to higher l. The E-mode spectrum, which is detected at 11 sigma significance, is in agreement with cosmological predictions and with previous work at other frequencies and angular resolutions. The BB power spectrum provides one of the best limits to date on B-mode power at 4.8 mu K-2 (95% confidence). C1 [Bischoff, C.; Smith, K. M.; Vanderlinde, K.; Hedman, M. M.; Winstein, B.] Univ Chicago, Kavli Inst Cosmol Phys, Enrico Fermi Inst, Dept Phys, Chicago, IL 60637 USA. [Hyatt, L.; McMahon, J. J.; Nixon, G. W.; Barkats, D.; Farese, P.; Staggs, S. T.] Princeton Univ, Dept Phys, Princeton, NJ 08544 USA. [Samtleben, D.] Max Planck Inst Radioastron, D-53121 Bonn, Germany. [Gaier, T.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Gundersen, J. O.] Univ Miami, Dept Phys, Coral Gables, FL 33146 USA. RP Bischoff, C (reprint author), Univ Chicago, Kavli Inst Cosmol Phys, Enrico Fermi Inst, Dept Phys, Chicago, IL 60637 USA. OI Barkats, Denis/0000-0002-8971-1954; Bischoff, Colin/0000-0001-9185-6514 FU NSF [PHY-9984440, PHY-0355328, PHY-0551142]; Princeton University; Kavli Institute for Cosmological Physics; Kavli Foundation; NASA Office of Space Science FX We thank Dale Fixsen for convincing us to try a ring scan strategy and Chris Hirata for arguing the virtues of the half-Fourier map space to us. We thank John Carlstrom, Tom Crawford, Joe Fowler, Wayne Hu, Norman Jarosik, Steve Meyer, Lyman Page, and David Spergel for many helpful conversations; Rob Lucy, Eugenia Stefanescu, and Michelle Yeh for help with the data collection; and Glenn Atkinson, Bill Dix, Ted Griffiths, Mike Peloso, Elizabeth Pod, Fukun Tang, and Laszlo Varga for their contributions to the design and construction of the experiment. Many thanks to Neelesh Arora, Valeri Galtsev, and Vinod Gupta for computing support and to Julian Borrill for managing the CMB analysis group at the NERSC cluster. We are grateful to Lucent Technologies for the use of the 7 m antenna and to Tod Sizer, Bob Wilson, and Greg Wright for their support and assistance. We gratefully acknowledge support from NSF grants PHY-9984440 and PHY-0355328 and Princeton University; and the Kavli Institute for Cosmological Physics, funded by the Kavli Foundation and NSF grant PHY-0551142. We acknowledge the use of the Legacy Archive for Microwave Background Data Analysis ( LAMBDA). Support for LAMBDA is provided by the NASA Office of Space Science. Some of the results in this paper have been derived using the HEALPix (Gorski et al. 2005) package. NR 42 TC 66 Z9 66 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 SEP 10 PY 2008 VL 684 IS 2 BP 771 EP 789 DI 10.1086/590487 PG 19 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 343XH UT WOS:000258889000001 ER PT J AU Berti, E Volonteri, M AF Berti, Emanuele Volonteri, Marta TI Cosmological black hole spin evolution by mergers and accretion SO ASTROPHYSICAL JOURNAL LA English DT Article DE black hole physics; cosmology : theory; galaxies : evolution; gravitational waves ID BINARIES; MASS; COALESCENCE; MORPHOLOGY; MODELS; DISCS AB Using recent results from numerical relativity simulations of black hole mergers, we revisit previous studies of cosmological black hole spin evolution. We show that mergers are very unlikely to yield large spins, unless alignment of the spins of the merging holes with the orbital angular momentum is very efficient. We analyze the spin evolution in three specific scenarios: (1) spin evolves only through mergers, (2) spin evolves through mergers and prolonged accretion episodes, and (3) spin evolves through mergers and short-lived ( chaotic) accretion episodes. We study how different diagnostics can distinguish between these evolutionary scenarios, assessing the discriminating power of gravitational-wave measurements and X-ray spectroscopy. Gravitational radiation can produce three different types of spin measurements, yielding, respectively, the spins of the two black holes in a binary inspiral prior to merger, the spin of the merger remnant ( as encoded in the ring-down waves), and the spin of "single'' black holes during the extreme mass-ratio inspiral (EMRI) of compact objects. The latter spin population is also accessible to iron-line measurements. We compute and compare the spin distributions relevant for these different observations. If iron-line measurements and gravitational-wave observations of EMRIs only yield dimensionless spins j = J/M-2 > 0: 9, then prolonged accretion should be responsible for spin-up, and chaotic accretion scenarios would be very unlikely. If only a fraction of the whole population of low-redshift black holes spins rapidly, spin-alignment during binary mergers ( rather than prolonged accretion) could be responsible for spin-ups. C1 [Berti, Emanuele] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Volonteri, Marta] Univ Michigan, Dept Astron, Ann Arbor, MI 48109 USA. RP Berti, E (reprint author), CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RI Berti, Emanuele/C-9331-2016 OI Berti, Emanuele/0000-0003-0751-5130 FU NASA FX We thank Curt Cutler, Tom Prince, and the LISA science performance evaluation task force for discussions. E. B 's research was supported by an appointment to the NASA Postdoctoral Program at JPL, administered by Oak Ridge Associated Universities through a contract with NASA. Government sponsorship is acknowledged. NR 46 TC 150 Z9 154 U1 1 U2 6 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 SEP 10 PY 2008 VL 684 IS 2 BP 822 EP 828 DI 10.1086/590379 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 343XH UT WOS:000258889000006 ER PT J AU Sambruna, RM Donato, D Cheung, CC Tavecchio, F Maraschi, L AF Sambruna, Rita M. Donato, Davide Cheung, C. C. Tavecchio, F. Maraschi, L. TI A kiloparsec-scale X-ray jet in the BL Lac source S5 2007+777 SO ASTROPHYSICAL JOURNAL LA English DT Article DE BL Lacertae objects : individual (S5 2007+777); galaxies : jets; X-rays : galaxies; X-rays : individual (S5 2007+777) ID HUBBLE-SPACE-TELESCOPE; LACERTAE OBJECTS; RADIO JETS; HST OBSERVATIONS; COMPLETE SAMPLE; HOST GALAXIES; DEEP CHANDRA; PKS 0521-365; EMISSION; DECELERATION AB X-ray jets in AGNs are commonly observed in FR II and FR I radio galaxies, but rarely in BL Lac objects, most probably due to their orientation close to the line of sight and the ensuing foreshortening effects. Only three BL Lac objects are known so far to contain a kpc-scale X-ray jet. In this paper we present the evidence for the existence of a fourth extended X-ray jet in the classical radio-selected source S5 2007+ 777, which for its hybrid FR I and FR II radio morphology has been classified as a HYMOR (HYbrid MOrphology Radio source). Our Chandra ACIS-S observations of this source revealed an X-ray counterpart to the 19 '' long radio jet. Interestingly, the X- ray properties of the kpc-scale jet in S5 2007+ 777 are very similar to those observed in FR II jets. First, the X- ray morphology closely mirrors the radio one, with the X- rays being concentrated in the discrete radio knots. Second, the X- ray continuum of the jet/ brightest knot is described by a very hard power law, with photon index Gamma(X) similar to 1, although the uncertainties are large. Third, the optical upper limit from archival HST data implies a concave radio-to-X-ray SED. If the X- ray emission is attributed to IC/CMB with equipartition, strong beaming (delta = 13) is required, implying a very large scale (Mpc) jet. The beaming requirement can be somewhat relaxed assuming a magnetic field lower than equipartition. Alternatively, synchrotron emission from a second population of very high-energy electrons is viable. Comparison to other HYMOR jets detected with Chandra is discussed, as well as general implications for the origin of the FR I/FR II division. C1 [Sambruna, Rita M.; Donato, Davide; Cheung, C. C.] NASA GSFC, Greenbelt, MD 20771 USA. [Tavecchio, F.; Maraschi, L.] Osserv Astron Brera, I-20121 Milan, Italy. RP Sambruna, RM (reprint author), NASA GSFC, Code 661, Greenbelt, MD 20771 USA. EM rms@milkyway.gsfc.nasa.gov FU NASA [NAS 5-26555] FX The VLA is a facility of the National Radio Astronomy Observatory is operated by Associated Universities, Inc. under a cooperative agreement with the National Science Foundation. Based in part on observations made with the NASA/ESA Hubble Space Telescope, obtained from the data archive at the STScI. STScI is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. 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. C. C. C. was supported in part 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. NR 43 TC 16 Z9 17 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 SEP 10 PY 2008 VL 684 IS 2 BP 862 EP 869 DI 10.1086/589918 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 343XH UT WOS:000258889000011 ER PT J AU Eisenhardt, PRM Brodwin, M Gonzalez, AH Stanford, SA Stern, D Barmby, P Brown, MJI Dawson, K Dey, A Doi, M Galametz, A Jannuzi, BT Kochanek, CS Meyers, J Morokuma, T Moustakas, LA AF Eisenhardt, Peter R. M. Brodwin, Mark Gonzalez, Anthony H. Stanford, S. Adam Stern, Daniel Barmby, Pauline Brown, Michael J. I. Dawson, Kyle Dey, Arjun Doi, Mamoru Galametz, Audrey Jannuzi, B. T. Kochanek, C. S. Meyers, Joshua Morokuma, Tomoki Moustakas, Leonidas A. TI Clusters of galaxies in the first half of the universe from the IRAC shallow survey SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : clusters : general; surveys ID SPITZER-SPACE-TELESCOPE; COLOR-MAGNITUDE RELATION; BAND LUMINOSITY FUNCTION; INFRARED ARRAY CAMERA; PROBE WMAP OBSERVATIONS; STAR-FORMING GALAXIES; ESO IMAGING SURVEY; WIDE-FIELD SURVEY; X-RAY SURVEY; RED-SEQUENCE AB We have identified 335 galaxy cluster and group candidates, 106 of which are at z > 1, using a 4.5 mu m-selected sample of objects from a 7.25 deg(2) region in the Spitzer Infrared Array Camera (IRAC) Shallow Survey. Clusters were identified as three-dimensional overdensities using a wavelet algorithm, based on photometric redshift probability distributions derived from IRAC and NOAO Deep Wide-Field Survey data. We estimate only similar to 10% of the detections are spurious. To date 12 of the z > 1 candidates have been confirmed spectroscopically, at redshifts from 1.06 to 1.41. Velocity dispersions of similar to 750 km s(-1) for two of these argue for total cluster masses well above 10(14) M-circle dot, as does the mass estimated from the rest-frame near-infrared stellar luminosity. Although not selected to contain a red sequence, some evidence for red sequences is present in the spectroscopically confirmed clusters, and brighter galaxies are systematically redder than the mean galaxy color in clusters at all redshifts. The mean I - [3.6] color for cluster galaxies up to z similar to 1 is well matched by a passively evolving model in which stars are formed in a 0.1 Gyr burst starting at redshift z(f) = 3. At z > 1, a wider range of formation histories is needed, but higher formation redshifts (i.e., z(f) > 3) are favored for most clusters. C1 [Eisenhardt, Peter R. M.; Stern, Daniel; Galametz, Audrey; Moustakas, Leonidas A.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Brodwin, Mark; Jannuzi, B. T.] Natl Opt Astron Observ, Tucson, AZ 85719 USA. [Gonzalez, Anthony H.] Univ Florida, Dept Astron, Gainesville, FL 32611 USA. [Stanford, S. Adam] Univ Calif Davis, Davis, CA 95618 USA. [Stanford, S. Adam] Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Livermore, CA 94550 USA. [Barmby, Pauline] Univ Western Ontario, Dept Phys & Astron, London, ON N6A 3K7, Canada. [Brown, Michael J. I.] Monash Univ, Sch Phys, Clayton, Vic 3800, Australia. [Dawson, Kyle; Meyers, Joshua] EO Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. [Doi, Mamoru; Morokuma, Tomoki] Univ Tokyo, Inst Astron, Grad Sch Sci, Mitaka, Tokyo 1810015, Japan. [Galametz, Audrey] Observ Astron, F-67000 Strasbourg, France. [Kochanek, C. S.] Ohio State Univ, Dept Astron, Columbus, OH 43210 USA. [Meyers, Joshua] Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. [Morokuma, Tomoki] Natl Astron Observ Japan, Mitaka, Tokyo 1818588, Japan. RP Eisenhardt, PRM (reprint author), CALTECH, Jet Prop Lab, MS 169-327,4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM peter.eisenhardt@jpl.nasa.gov RI Brown, Michael/B-1181-2015; Barmby, Pauline/I-7194-2016; OI Brown, Michael/0000-0002-1207-9137; Barmby, Pauline/0000-0003-2767-0090; Moustakas, Leonidas/0000-0003-3030-2360 FU National Optical Astronomy Observatory (NOAO); NASA; W. M. Keck Foundation; University of California, Lawrence Livermore National Laboratory [W-7405Eng-48]; Office of Science, Department of Energy [DE-AC02-05CH11231] FX We thank Mark Dickinson, Emily MacDonald, and Hyron Spinrad for generously making time available on their scheduled nights for the DEIMOS observations reported here. Naoki Yasuda, Naohiro Takanashi, Yutaka Ihara, Kohki Konishi, and Hiroyuki Utsunomiya assisted with observations at the Subaru Telescope. Roberto De Propris provided the integrated luminosity for Coma Cluster galaxies. Thoughtful comments from the anonymous referee improved the presentation of this work. The IRAC Shallow Survey was executed using guaranteed observing time contributed by G. Fazio, G. Rieke, M. Rieke, M. Werner, and E. Wright. 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 work made use of images and data products provided by the NOAO Deep Wide-Field Survey, which is supported by the National Optical Astronomy Observatory (NOAO). NOAO is operated by AURA, Inc., under a cooperative agreement with the National Science Foundation. 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. Some of the data presented were collected at the Subaru Telescope, which is operated by the National Astronomical Observatory of Japan. The work of SAS was performed under the auspices of the US Department of Energy, National Nuclear Security Administration, by the University of California, Lawrence Livermore National Laboratory, under contract W-7405Eng-48. The work of K. D. and J.M. was partially supported by the Director, Office of Science, Department of Energy, under grant DE-AC02-05CH11231. NR 88 TC 155 Z9 155 U1 1 U2 6 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 SEP 10 PY 2008 VL 684 IS 2 BP 905 EP 932 DI 10.1086/590105 PG 28 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 343XH UT WOS:000258889000014 ER PT J AU Ferrante, RF Moore, MH Spiliotis, MM Hudson, RL AF Ferrante, Robert F. Moore, Marla H. Spiliotis, Morgan M. Hudson, Reggie L. TI Formation of interstellar OCS: Radiation chemistry and IR spectra of precursor ices SO ASTROPHYSICAL JOURNAL LA English DT Article DE astrochemistry; ISM : molecules; methods : laboratory; techniques : spectroscopic ID CARBONYL SULFIDE OCS; INFRARED-SPECTROSCOPY; HOT CORES; WATER ICE; SO2; ABSORPTION; MATRICES; W33A; H2S; MOLECULES AB Extensive experimental studies have been performed on the solid-state formation of the OCS molecule in proton-irradiated water-free and water-dominated ices containing CO or CO(2) as the carbon source and H(2)S or SO(2) as the sulfur source. In each case OCS is readily formed. Production efficiency follows the trends CO > CO(2) and H(2)S > SO(2) as C, O- and S-sources, respectively. In water-dominated ices, OCS production appears to be enhanced for CO : H(2)S reactants. The mechanism of formation of OCS appears to be the reaction of CO with free S atoms produced by fragmentation of the sulfur parent species. While OCS is readily formed by irradiation, it is also the most easily destroyed on continued exposure. In H(2)O-dominated ices the half-life of H(2)S, SO(2), and OCS is similar to 2 eV molecule(-1), corresponding to similar to 7 million years in a cold dense interstellar cloud environment processed by cosmic-ray protons. The spectral profile of the v(3) band of OCS is highly dependent on temperature and ice composition, and changes with radiation processing. These effects can be used in theoretical modeling of interstellar infrared (IR) spectra; a laboratory spectrum of irradiated H(2)O : CO : H(2)S, warmed to 50 K, provides a good fit to the 2040 cm(-1) feature in the W33A spectrum. The identification of OCS in CO(2)-dominated ices provides a further challenge, due to the overlap of the OCS band with that of CO(3) formed from irradiation of the host ice. The two features can be unraveled by a curve-fitting procedure. It is the width of the 2040 cm(-1) band that will help observers determine if features identified in CO(2)-rich ices are due to OCS or to CO(3). C1 [Ferrante, Robert F.; Spiliotis, Morgan M.] USN Acad, Dept Chem, Annapolis, MD 21402 USA. [Moore, Marla H.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Hudson, Reggie L.] Eckerd Coll, Dept Chem, St Petersburg, FL 33711 USA. RP Ferrante, RF (reprint author), USN Acad, Dept Chem, 572 Holloway Rd, Annapolis, MD 21402 USA. RI Hudson, Reggie/E-2335-2012 FU NASA [NNG 05-GJ46G]; Office of Naval Research [N0001407WR20077] FX The authors acknowledge support through The Goddard Center for Astrobiology, and NASA's Planetary Atmospheres, Outer Planets, and Planetary Geology and Geophysics programs. In addition, we thank Steve Brown, Claude Smith, and Eugene Gerashchenko, members of the Radiation Laboratory at NASA Goddard, for operation of the accelerator. R. L. H. acknowledges support from NASA Grant NNG 05-GJ46G. M. M. S. gratefully acknowledges the Office of Naval Research for partial support of this work on funding document N0001407WR20077. NR 46 TC 24 Z9 24 U1 0 U2 10 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 SEP 10 PY 2008 VL 684 IS 2 BP 1210 EP 1220 DI 10.1086/590362 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 343XH UT WOS:000258889000032 ER PT J AU Nishikawa, T Takami, M Hayashi, M Wiseman, J Pyo, TS AF Nishikawa, Takayuki Takami, Michihiro Hayashi, Masahiko Wiseman, Jennifer Pyo, Tae-Soo TI Subaru high-dispersion spectroscopy of H alpha and [N II] 6583 angstrom emission in the HH 46/47 jet SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : Herbig-Haro objects; ISM : jets and outflows ID HUBBLE-SPACE-TELESCOPE; HERBIG-HARO OBJECTS; PLANETARY CAMERA 2; MASS-LOSS RATES; MOLECULAR OUTFLOWS; BOW-SHOCK; YOUNG STARS; PROPER MOTIONS; STELLAR JETS; HH-47 JET AB We present slit-scan observations of the H alpha and [N II] 6583 8 emission lines toward the HH 46/47 jet with the Subaru Telescope. The spectral resolution of R = 3.6 x 10(4) allowed us to study the kinematics of individual features in unprecedented detail. The spectra show (1) the main jet component (V-LSR similar to -160 km s(-1)), which is seen in both H alpha and [N II] emission, and ( 2) distinct lower velocity components (V-LSR vertical bar less than or similar to 120 km s(-1)), which are clearly seen in H alpha but are marginal or absent in [N II]. The measured [N II]/H alpha ratios are 0.2-0.5 and < 0.2 (typically < 0.1) in these two components, respectively. The velocities of the H alpha and [N II] emission in the main jet component match each other well, suggesting that these are associated with the ejecta. The low-velocity components are associated with one-sided bow shocks and an H alpha filament, where the jet interacts with the ambient gas. The line profiles at the bow shocks and the H alpha filament suggest that the surrounding gas moves outward by similar to 200 km s(-1) due to prompt entrainment. The difference in excitation conditions between the two velocity components is explained if the preshock gas is partially ionized in the main jet component, at the apices of the bow shocks and the H alpha filaments, while the ambient gas is almost neutral. C1 [Nishikawa, Takayuki; Hayashi, Masahiko] Grad Univ Adv Studies, Dept Astron Sci, Hilo, HI 96720 USA. [Wiseman, Jennifer] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Nishikawa, Takayuki; Takami, Michihiro; Hayashi, Masahiko; Pyo, Tae-Soo] Natl Inst Nat Sci, Natl Astron Observ Japan, Subaru Telescope, Hilo, HI 96720 USA. RP Nishikawa, T (reprint author), Grad Univ Adv Studies, Dept Astron Sci, 650 N Aohoku Pl, Hilo, HI 96720 USA. EM hiro@asiaa.sinica.edu.tw FU Subaru Telescope [HST WFPC2 F656N] FX We acknowledge the anonymous referees for helpful comments. We are grateful to P. Hartigan for providing us with his HST WFPC2 F656N image, and also for fruitful discussion. We also thank the staff at the Subaru Telescope for their excellent support. This research has made use of the NASA's Astrophysics Data System Abstract Service. NR 53 TC 3 Z9 3 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 SEP 10 PY 2008 VL 684 IS 2 BP 1260 EP 1272 DI 10.1086/588644 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 343XH UT WOS:000258889000036 ER PT J AU Zenitani, S Hesse, M AF Zenitani, S. Hesse, M. TI Self-regulation of the reconnecting current layer in relativistic pair plasma reconnection SO ASTROPHYSICAL JOURNAL LA English DT Article DE magnetic fields; plasmas; relativity ID COLLISIONLESS MAGNETIC RECONNECTION; PARTICLE-ACCELERATION; GUIDE-FIELD; SIMULATIONS; DISSIPATION; FLUX AB We investigate properties of the reconnecting current layer in relativistic pair plasma reconnection. We found that the current layer self-regulates its thickness when the current layer runs out current carriers, and so relativistic reconnection retains a fast reconnection rate. Constructing a steady state Sweet-Parker model, we discuss conditions for the current sheet expansion. Based on the energy argument, we conclude that the incompressible assumption is invalid in relativistic Sweet-Parker reconnection. The guide field cases are more incompressible than the antiparallel cases, and we find a more significant current sheet expansion. C1 [Zenitani, S.; Hesse, M.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Zenitani, S (reprint author), NASA, Goddard Space Flight Ctr, 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 JAXA/ISAS; NASA Center for Computational Sciences; NASA's MMS SMART FX The authors are grateful to A. Klimas, M. Kuznetsova, and H. Takahashi for useful discussions. The authors also thank the anonymous referee for his/her constructive comments and careful evaluation of this manuscript. This research was supported by JAXA/ISAS, the NASA Center for Computational Sciences, and NASA's MMS SMART mission. One of the authors (S.Z.) gratefully acknowledges support from NASA's postdoctoral program. NR 26 TC 17 Z9 17 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 SEP 10 PY 2008 VL 684 IS 2 BP 1477 EP 1485 DI 10.1086/590425 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 343XH UT WOS:000258889000058 ER PT J AU Mushotzy, RF Winter, LM McIntosh, DH Tueller, J AF Mushotzy, Richard F. Winter, Lisa M. McIntosh, Daniel H. Tueller, Jack TI Correlations of the IR luminosity and Eddington ratio with a hard X-ray-selected sample of active galactic nuclei SO ASTROPHYSICAL JOURNAL LETTERS LA English DT Article DE galaxies : Seyfert; surveys; X-rays : galaxies ID BLACK-HOLE MASS; ENERGY-DISTRIBUTIONS; FUNDAMENTAL PLANE; SEYFERT-GALAXIES; COSMIC EVOLUTION; QUASAR; CALIBRATION; SPECTRA; RADIUS; ATLAS AB We use the Swift Burst Alert Telescope (BAT) sample of hard X-ray-selected active galactic nuclei (AGN) with a median redshift of 0.03 and the 2MASS J- and K-band photometry to examine the correlation of hard X-ray emission to Eddington ratio as well as the relationship of the J- and K-band nuclear luminosity to the hard X-ray luminosity. The BAT sample is almost unbiased by the effects of obscuration and thus offers the first large unbiased sample for the examination of correlations between different wavelength bands. We find that the near-IR nuclear J-and K-band luminosity is related to the BAT (14-195 keV) luminosity over a factor of 10(3) in luminosity (L-IR approximate to L-BAT(1.25)) and thus is unlikely to be due to dust. We also find that the Eddington ratio is proportional to the X-ray luminosity. This new result should be a strong constraint on models of the formation of the broadband continuum. C1 [Mushotzy, Richard F.; Tueller, Jack] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Winter, Lisa M.] Univ Maryland, College Pk, MD 20742 USA. [McIntosh, Daniel H.] Univ Massachusetts, Amherst, MA 01003 USA. RP Mushotzy, RF (reprint author), NASA, Goddard Space Flight Ctr, Code 661, Greenbelt, MD 20771 USA. RI Tueller, Jack/D-5334-2012; OI Winter, Lisa/0000-0002-3983-020X FU National Aeronautics and Space Administration (NASA) [NAG5-13102] FX D. H. M. acknowledges support from the National Aeronautics and Space Administration (NASA) under LTSA grant NAG5-13102 issued through the Office of Space Science. This publication makes use of data products from the Two Micron All Sky Survey. We acknowledge the work that the Swift BAT team has done that has made this work possible. NR 39 TC 16 Z9 16 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA J9 ASTROPHYS J LETT JI Astrophys. J. Lett. PD SEP 10 PY 2008 VL 684 IS 2 BP L65 EP L68 DI 10.1086/592196 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 345RS UT WOS:000259014700003 ER PT J AU Bauschlicher, CW AF Bauschlicher, Charles W., Jr. TI Clusters of hafnium, Hf(n) n=2-8 SO CHEMICAL PHYSICS LETTERS LA English DT Article ID DENSITY-FUNCTIONAL THEORY; TOTAL-ENERGY CALCULATIONS; WAVE BASIS-SET; MOLECULAR-DYNAMICS; METALS; TRANSITION; PSEUDOPOTENTIALS; ABSORPTION; EXCHANGE; SPECTRA AB Small Hf(n) clusters are studied using density functional theory. The clusters tend to have high symmetry with multiple metal bonds. The atomization energy converges slowly toward the bulk value. All of the vibrational modes are computed to be very weak in the infrared. Published by Elsevier B. V. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Bauschlicher, CW (reprint author), NASA, Ames Res Ctr, Mail Stop 230-3, Moffett Field, CA 94035 USA. EM Charles.W.Bauschlicher@nasa.gov NR 30 TC 7 Z9 7 U1 1 U2 2 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 SEP 10 PY 2008 VL 462 IS 4-6 BP 183 EP 187 DI 10.1016/j.cplett.2008.07.100 PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 343CT UT WOS:000258830900008 ER PT J AU Mueller, KJ Di Girolamo, L Fromm, M Palm, SP AF Mueller, Kevin J. Di Girolamo, Larry Fromm, Mike Palm, Steven P. TI Stereo observations of polar stratospheric clouds SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article AB We present the first observations of polar stratospheric clouds (PSCs) within near-infrared (NIR) satellite images by using the Multi-angle Imaging SpectroRadiometer (MISR) to stereoscopically identify clouds with altitudes above the tropopause. Rather than using the operational MISR stereo product, a tailored stereo height algorithm operating upon MISR's most oblique viewing cameras is employed to identify PSC. Cloud top heights retrieved by this algorithm for scenes observed during the 2003 Antarctic Spring exhibit bias relative to the satellite-borne lidar, GLAS, of -0.60 +/- 1.71 km for low (1-5 km altitude) tropospheric clouds, -0.35 +/- 1.48 km for high (> 5 km altitude) tropospheric clouds, and 0.77 +/- 1.86 km for low (< 18 km altitude) stratospheric clouds. During this period, MISR captured a Sep. 30th intensification of PSC spanning over 1 million sq. km and occurring as the apparent result of synoptic scale isentropic uplift associated with a potential vorticity anomaly tied to planetary waves, but likely also strengthened by a nearby tropospheric depression. C1 [Mueller, Kevin J.; Di Girolamo, Larry] Univ Illinois, Dept Atmospher Sci, Urbana, IL 61801 USA. [Palm, Steven P.] NASA, Goddard Space Flight Ctr, Sci Syst & Applicat Inc, Greenbelt, MD 20771 USA. RP Mueller, KJ (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,M-S T1721, Pasadena, CA 91109 USA. EM kmueller@jpl.nasa.gov RI Fromm, Michael/F-4639-2010 NR 8 TC 4 Z9 4 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 SEP 10 PY 2008 VL 35 IS 17 AR L17813 DI 10.1029/2008GL033792 PG 6 WC Geosciences, Multidisciplinary SC Geology GA 348GS UT WOS:000259199600001 ER PT J AU Smith, AK Marsh, DR Russell, JM Mlynczak, MG Martin-Torres, FJ Kyrola, E AF Smith, Anne K. Marsh, Daniel R. Russell, James M., III Mlynczak, Martin G. Martin-Torres, F. Javier Kyroelae, Erkki TI Satellite observations of high nighttime ozone at the equatorial mesopause SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID TERRESTRIAL MIDDLE ATMOSPHERE; DOUBLE-RESONANCE MEASUREMENTS; INFRARED LIMB EMISSION; LOWER THERMOSPHERE; MESOSPHERIC OZONE; TEMPERATURE-RANGE; GAS-MIXTURES; BAND; DENSITIES; INFERENCE AB Measurements by the Sounding of the Atmosphere using Broadband Emission Radiometry instrument enable the characterization of the seasonal variation of ozone and temperature in the upper mesosphere. These are the first global measurements that resolve both the structure of the secondary ozone maximum at night and the temperature over all seasons of the year. The average nighttime mixing ratios at the altitude of the maximum vary with latitude and season. Analysis shows that the highest mixing ratios are clustered near the equator during equinoxes. The high ozone mixing ratios are observed in exactly the place and time at which the diurnal tide is largest. The diurnal tidal phase is such that coldest temperatures at 95 km occur near midnight. The high ozone is coincident with regions that have both low temperature and low amounts of atomic hydrogen. We focus particularly on ozone mixing ratios in the range of 18-50 ppmv; these occur intermittently in the equinoctial tropics on days when the night temperature is particularly cold. The occurrence of ozone maxima over 20 ppmv was unexpected but is shown in this paper to be consistent with theory and is a result of large-amplitude diurnal tides. The same seasonal and latitudinal characteristics are seen in ozone density measured by Global Ozone Monitoring by Occultation of Stars. C1 [Smith, Anne K.; Marsh, Daniel R.] Natl Ctr Atmospher Res, Div Atmospher Chem, Boulder, CO 80307 USA. [Russell, James M., III] Hampton Univ, Ctr Atmospher Sci, Hampton, VA 23668 USA. [Mlynczak, Martin G.] NASA Langley Res, Hampton, VA USA. [Martin-Torres, F. Javier] Analyt Serv & Mat Inc, Hampton, VA 23666 USA. [Kyroelae, Erkki] Finnish Meteorol Inst, FIN-00101 Helsinki, Finland. RP Smith, AK (reprint author), Natl Ctr Atmospher Res, Div Atmospher Chem, POB 3000, Boulder, CO 80307 USA. EM aksmith@ucar.edu RI Marsh, Daniel/A-8406-2008; Mlynczak, Martin/K-3396-2012; Kyrola, Erkki/E-1835-2014; Martin-Torres, Francisco Javier/G-6329-2015 OI Marsh, Daniel/0000-0001-6699-494X; Martin-Torres, Francisco Javier/0000-0001-6479-2236 FU NASA Science Mission Directorate; National Center for Atmospheric Research; University Corporation for Atmospheric Research; National Science Foundation FX Support for this work was provided by the NASA Science Mission Directorate. The National Center for Atmospheric Research is operated by the University Corporation for Atmospheric Research under the sponsorship of the National Science Foundation. NR 33 TC 23 Z9 23 U1 1 U2 4 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 SEP 10 PY 2008 VL 113 IS D17 AR D17312 DI 10.1029/2008JD010066 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 348HA UT WOS:000259200400008 ER PT J AU Chahine, MT Chen, L Dimotakis, P Jiang, X Li, QB Olsen, ET Pagano, T Randerson, J Yung, YL AF Chahine, M. T. Chen, Luke Dimotakis, Paul Jiang, Xun Li, Qinbin Olsen, Edward T. Pagano, Thomas Randerson, James Yung, Yuk L. TI Satellite remote sounding of mid-tropospheric CO2 SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SOUTHERN-HEMISPHERE; CARBON-DIOXIDE; STORM TRACKS; AIR; TRANSPORT AB Human activity has increased the concentration of the earth's atmospheric carbon dioxide, which plays a direct role in contributing to global warming. Mid-tropospheric CO2 retrieved by the Atmospheric Infrared Sounder shows a substantial spatiotemporal variability that is supported by in situ aircraft measurements. The distribution of middle tropospheric CO2 is strongly influenced by surface sources and large-scale circulations such as the mid-latitude jet streams and by synoptic weather systems, most notably in the summer hemisphere. In addition, the effects of stratosphere-troposphere exchange are observed during a final stratospheric warming event. The results provide the means to understand the sources and sinks and the lifting of CO2 from surface layers into the free troposphere and its subsequent transport around the globe. These processes are not adequately represented in three chemistry-transport models that have been used to study carbon budgets. C1 [Chahine, M. T.; Chen, Luke; Jiang, Xun; Li, Qinbin; Olsen, Edward T.; Pagano, Thomas] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Dimotakis, Paul; Yung, Yuk L.] CALTECH, Pasadena, CA 91125 USA. [Randerson, James] Univ Calif Irvine, Dept Earth Syst Sci, Irvine, CA 92697 USA. RP Chahine, MT (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM chahine@jpl.nasa.gov FU National Aeronautic and Space Administration FX We thank Charles E. Miller of JPL for valuable comments and suggestions on the manuscript. We thank the reviewers, Steve Pawson and the other anonymous reviewers, for their thorough and constructive reviews. This work was carried out at the Jet Propulsion Laboratory, California Institute of Technology under contract with the National Aeronautic and Space Administration. NR 22 TC 90 Z9 98 U1 2 U2 16 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 SEP 9 PY 2008 VL 35 IS 17 AR L17807 DI 10.1029/2008GL035022 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 348GR UT WOS:000259199500004 ER PT J AU Yang, K Pinker, RT Ma, Y Koike, T Wonsick, MM Cox, SJ Zhang, Y Stackhouse, P AF Yang, Kun Pinker, Rachel T. Ma, Yaoming Koike, Toshio Wonsick, Margaret M. Cox, Stephen J. Zhang, Yuanchong Stackhouse, Paul TI Evaluation of satellite estimates of downward shortwave radiation over the Tibetan Plateau SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SOLAR IRRADIANCE; DATA SETS; SURFACE; SUMMER; SYSTEM; ISCCP; UNCERTAINTIES; MOISTURE; CLIMATE; MONSOON AB The state-of-the-art satellite products of downward shortwave radiation over the Tibetan Plateau against ground observations are evaluated in this study. The satellite products include the International Satellite Cloud Climatology Project-Flux Data (ISCCP-FD) as produced at the NASA Goddard Institute for Space Studies (GISS) from the ISCCP D1 data, the Global Energy and Water Cycle Experiment-Surface Radiation Budget (GEWEX-SRB) results as derived at the NASA Langley Research Center (LaRC) from the ISCCP DX data, and a University of Maryland product derived with a modified version of the University of Maryland Surface Radiation Budget (UMD-SRB) model as implemented with METEOSAT-5 observations. These products are at different spatial and temporal resolutions, and the evaluation is performed at their native resolutions. Comparisons indicate that, in this region of great variation in elevation, using hourly, spatially homogeneous, and high resolution satellite data (UMD-SRB) compares more favorably with surface measurements than products that use three hourly, sparse subsamples at coarse resolutions (ISCCP-FD and GEWEX-SRB). Discrepancies among the satellite products are usually larger in highly variable terrain (such as in the Himalayas region) and smaller for nonvariable terrain (such as in the central Plateau). This suggests that errors of satellite products are spatially dependent over the Tibet. Therefore caution needs to be exercised when extending comparison results based on limited in situ data from accessible sites to the entire Plateau. Attention should be also given to the quality of input parameters besides cloud properties, as there are large discrepancies among the satellite products for clear-sky radiation. C1 [Yang, Kun; Ma, Yaoming] Chinese Acad Sci, Inst Tibetan Plateau Res, Beijing 100085, Peoples R China. [Pinker, Rachel T.; Wonsick, Margaret M.] Univ Maryland, Dept Atmospher & Ocean Sci, College Pk, MD 20742 USA. [Koike, Toshio] Univ Tokyo, Dept Civil Engn, Bunkyo Ku, Tokyo 1138656, Japan. [Cox, Stephen J.] Analyt Serv & Mat Inc, Hampton, VA 23666 USA. [Zhang, Yuanchong] Columbia Univ, NASA GISS, New York, NY USA. [Stackhouse, Paul] NASA Langley Res Ctr, Hampton, VA 23681 USA. RP Yang, K (reprint author), Chinese Acad Sci, Inst Tibetan Plateau Res, POB 2871, Beijing 100085, Peoples R China. EM yangk@itpcas.ac.cn RI Pinker, Rachel/F-6565-2010; Yang, Kun/G-8390-2011 OI Yang, Kun/0000-0002-0809-2371 FU NASA [NNG05GB35G, NNG04GD65G] FX This work was supported by the "Hundred Talent'' Project of Chinese Academy of Sciences. The in situ data used in this paper were obtained under the GAME/Tibet project, which was supported by the MEXT, FRSGC, NASDA of Japan, Chinese Academy of Science, and Asian Pacific Network. GEWEX/SRB data were obtained from the NASA Langley Research Center Atmospheric Science Data Center. The work to produce the high resolution radiative fluxes was supported under NASA grant NNG05GB35G to the University of Maryland and benefited from support under NASA grant NNG04GD65G. The authors wish to thank Yves Govaerts and the staff at the European Organization for the Exploitation of Meteorological Satellites (EUMETSAT) Archive and Retrieval Facility for providing the Meteosat-5 observations and consulting on the calibration. Thanks are also due to the National Snow and Ice Data Center (NSIDC) at the University of Colorado, Boulder, CO, for providing the IMS snow data, and to the NOAA-CIRES Climate Diagnostic Center for providing the NCEP Reanalysis II data. NR 38 TC 32 Z9 34 U1 1 U2 16 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 SEP 9 PY 2008 VL 113 IS D17 AR D17204 DI 10.1029/2007JD009736 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 348GZ UT WOS:000259200300003 ER PT J AU Schaefer, K Collatz, GJ Tans, P Denning, AS Baker, I Berry, J Prihodko, L Suits, N Philpott, A AF Schaefer, Kevin Collatz, G. James Tans, Pieter Denning, A. Scott Baker, Ian Berry, Joe Prihodko, Lara Suits, Neil Philpott, Andrew TI Combined Simple Biosphere/Carnegie-Ames-Stanford Approach terrestrial carbon cycle model SO JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES LA English DT Article ID SURFACE PARAMETERIZATION SIB2; ATMOSPHERIC CO2; LONG-TERM; INTERANNUAL VARIABILITY; BIOPHYSICAL PARAMETERS; STOMATAL CONDUCTANCE; SEASONAL CYCLE; GLOBAL FIELDS; TALL TOWER; NDVI DATA AB Biogeochemical models must include a broad variety of biological and physical processes to test our understanding of the terrestrial carbon cycle and to predict ecosystem biomass and carbon fluxes. We combine the photosynthesis and biophysical calculations in the Simple Biosphere model, Version 2.5 (SiB2.5) with the biogeochemistry from the Carnegie-Ames-Stanford Approach (CASA) model to create SiBCASA, a hybrid capable of estimating terrestrial carbon fluxes and biomass from diurnal to decadal timescales. We add dynamic allocation of Gross Primary Productivity to the growth and maintenance of leaves, roots, and wood and explicit calculation of autotrophic respiration. We prescribe leaf biomass using Leaf Area Index (LAI) derived from remotely sensed Normalized Difference Vegetation Index. Simulated carbon fluxes and biomass are consistent with observations at selected eddy covariance flux towers in the AmeriFlux network. Major sources of error include the steady state assumption for initial pool sizes, the input weather data, and biases in the LAI. C1 [Schaefer, Kevin] Univ Colorado, Natl Snow & Ice Data Ctr, Boulder, CO 80309 USA. [Collatz, G. James] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Tans, Pieter] NOAA, Earth Syst Res Lab, Boulder, CO 80305 USA. [Denning, A. Scott; Baker, Ian; Prihodko, Lara] Colorado State Univ, Dept Atmospher Sci, Ft Collins, CO 80523 USA. [Berry, Joe] Carnegie Inst Washington, Dept Global Ecol, Stanford, CA 94305 USA. [Suits, Neil] Montana State Univ, Dept Biol & Phys Sci, Billings, MT 59101 USA. [Philpott, Andrew] Natl Weather Serv, Middle Atlantic River Forecast Ctr, State Coll, PA 16803 USA. RP Schaefer, K (reprint author), Univ Colorado, Natl Snow & Ice Data Ctr, Boulder, CO 80309 USA. EM kevin.schaefer@nsidc.org RI collatz, george/D-5381-2012; Denning, Scott/F-4974-2011 OI Denning, Scott/0000-0003-3032-7875 FU National Aeronautics and Space Administration (NASA) [NNG05GD15G, NNX06AE65G, NNG05GF41G]; National Oceanic and Atmospheric Administration [NA07OAR4310115] FX This research was funded by the National Research Council Research Associateship Program in collaboration with Colorado State University under National Aeronautics and Space Administration (NASA) grant NNG05GD15G, NASA grant NNX06AE65G, NASA subcontract NNG05GF41G, National Oceanic and Atmospheric Administration grant NA07OAR4310115, and the Carbon Science Group at the NASA Goddard Space Flight Center. We thank the AmeriFlux Principle Investigators for providing the flux observations used in this study: P. Bakwin, B. Cook, K. Davis, M. Goulden, D. Hollinger, T. Meyers, R. Teclaw, S. Verma, W. Wang, K. Wilson, S. Wofsy, and C. Yi. NR 50 TC 56 Z9 56 U1 0 U2 12 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-BIOGEO JI J. Geophys. Res.-Biogeosci. PD SEP 9 PY 2008 VL 113 IS G3 AR G03034 DI 10.1029/2007JG000603 PG 13 WC Environmental Sciences; Geosciences, Multidisciplinary SC Environmental Sciences & Ecology; Geology GA 348HH UT WOS:000259201100001 ER PT J AU Senadheera, L Carl, EM Ivancic, TM Conradi, MS Bowman, RC Hwang, SJ Udovic, TJ AF Senadheera, Lasitha Carl, Erik M. Ivancic, Timothy M. Conradi, Mark S. Bowman, R. C., Jr. Hwang, S. -J. Udovic, Terrence J. TI Molecular H-2 trapped in AlH3 solid SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article DE hydrogen-storage materials; magnetic measurements; neutron scattering; nuclear resonances ID ALUMINUM-HYDRIDE; HYDROGEN; NMR; DECOMPOSITION; STABILITIES; RELAXATION; POLYMORPHS; PRESSURE; KINETICS; DEFECTS AB Solid aluminum hydride, AlH3, has been proposed and studied for applications in hydrogen storage. In some samples, a comparatively narrow feature in the proton NMR spectrum is observed; we demonstrate here that this peak is due to molecular hydrogen (H-2) trapped within the solid, presumably from earlier processing procedures or partial decomposition. Static and magic-angle spinning NMR show that the responsible species is highly mobile, even at I I K. Neutron-energy-gain spectra obtained at 3.5 K yield a feature at or near the free-rotor H-2 energy difference between the J = 1 and J = 0 states. Both NMR and neutron scattering demonstrate ortho-para conversion at low temperatures. Similar NMR signatures in other hydrogen-storage solids such as NaAlH4 may also be due to trapped H-2. (C) 2007 Elsevier B.V. All rights reserved. C1 [Senadheera, Lasitha; Carl, Erik M.; Ivancic, Timothy M.; Conradi, Mark S.] Washington Univ, Dept Phys, St Louis, MO 63130 USA. [Bowman, R. C., Jr.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Bowman, R. C., Jr.; Hwang, S. -J.] CALTECH, Div Chem & Chem Engn, Pasadena, CA 91125 USA. [Udovic, Terrence J.] Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP Conradi, MS (reprint author), Washington Univ, Dept Phys, St Louis, MO 63130 USA. EM msc@wuphys.wustl.edu FU DOE Basic Energy Sciences [DE-FG02-05ER46256]; NSF MRSEC [DMR-0520565]; DOE [DE-AI-01-05EE11104, DE-AI-01-06EE11105]; BES [DE-FG02-98ER45701]; National Aeronautical and Space Administration FX The authors gratefully acknowledge research support (at WU) from NSF grant DMR-0400512 and (at WU and Caltech) from DOE Basic Energy Sciences grant DE-FG02-05ER46256. The NMR facility (SH) at Caltech is supported by NSF award 9724240 and partially by the NSF MRSEC program with award DMR-0520565. This work was also partially supported by DOE through EERE Grants No. DE-AI-01-05EE11104 (NIST) and DE-AI-01-06EE11105 (JPL) and BES Grant No. DE-FG02-98ER45701 (NIST), and was partially performed at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautical and Space Administration. The authors thank J.G. Kulleck for the X-ray diffraction and SEM measurements at JPL. The sources of the samples are appreciated: J. Reilly and J. Graetz at Brookhaven National Laboratory and X. Tang, D. Mosher, and S. Opalka at UTRC. NR 30 TC 21 Z9 22 U1 4 U2 12 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD SEP 8 PY 2008 VL 463 IS 1-2 BP 1 EP 5 DI 10.1016/j.jallcom.2007.08.071 PG 5 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 341EP UT WOS:000258697300004 ER PT J AU Derimian, Y Leon, JF Dubovik, O Chiapello, I Tanre, D Sinyuk, A Auriol, F Podvin, T Brogniez, G Holben, BN AF Derimian, Y. Leon, J. -F. Dubovik, O. Chiapello, I. Tanre, D. Sinyuk, A. Auriol, F. Podvin, T. Brogniez, G. Holben, B. N. TI Radiative properties of aerosol mixture observed during the dry season 2006 over M'Bour, Senegal (African Monsoon Multidisciplinary Analysis campaign) SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID DUST EXPERIMENT SHADE; SAHARAN DUST; OPTICAL-PROPERTIES; SOUTHERN AFRICA; CARBONACEOUS AEROSOLS; TROPOSPHERIC AEROSOLS; MULTIPLE-SCATTERING; TROPICAL ATLANTIC; MINERAL AEROSOL; AERONET AB During the dry season in the Western Africa region the outbreaks of biomass burning aerosols occur on a background of frequent dust storms. In the frame of the African Monsoon Multidisciplinary Analysis (AMMA) campaign we studied optical properties and radiative effects of aerosol mixture and dust observed from January to March 2006 over M'Bour, Senegal. The aerosol burden during the observing period was notably below the average of previous years. However, variability of aerosol sizes and spectral absorption were found as representative. The lidar obtained extinction profiles suggested aerosol transport in two layers (or one elevated layer) for events with two different aerosol types, called aerosol mixture in the paper. Low-altitude transport was observed for dust. The broadband solar radiative fluxes and aerosol radiative effects were analyzed by combining measurements and simulations. The simulations relied on retrieved column aerosol properties and are products of Aerosol Robotic Network data processing. The 24-h average aerosol radiative effect yielded cooling at the bottom and at the top of the atmosphere for all the analyzed events of aerosol mixture and dust. The radiative efficiency (radiative effect scaled by optical thickness) at the bottom of the atmosphere and within the aerosol layer appeared to be stronger in case of mixture than in case of pure dust due to enhanced absorption ability of former. We also evaluated the importance of accounting for dust particles nonsphericity for simulating radiative effects. Our test showed that neglecting of aerosol particle shape can result in pronounced bias, up to 10% overestimation of daily average aerosol radiative effect. C1 [Derimian, Y.; Leon, J. -F.; Dubovik, O.; Chiapello, I.; Tanre, D.; Auriol, F.; Podvin, T.; Brogniez, G.] Univ Sci & Tech Lille Flandres Artois, CNRS, Opt Atmospher Lab, F-59655 Villeneuve Dascq, France. [Sinyuk, A.; Holben, B. N.] NASA, Goddard Space Flight Ctr, Terr Phys Lab, Greenbelt, MD 20771 USA. [Sinyuk, A.] Sci Syst & Applicat Inc, Lanham, MD USA. RP Derimian, Y (reprint author), Univ Sci & Tech Lille Flandres Artois, CNRS, Opt Atmospher Lab, F-59655 Villeneuve Dascq, France. EM derimian@loa.univ-lille1.fr RI Dubovik, Oleg/A-8235-2009 OI Dubovik, Oleg/0000-0003-3482-6460 NR 47 TC 41 Z9 42 U1 0 U2 2 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 SEP 6 PY 2008 VL 113 IS D17 AR D00C09 DI 10.1029/2008JD009904 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 345MK UT WOS:000259000700005 ER PT J AU Martin, MV Honrath, RE Owen, RC Li, QB AF Martin, M. Val Honrath, R. E. Owen, R. C. Li, Q. B. TI Seasonal variation of nitrogen oxides in the central North Atlantic lower free troposphere SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID OBSERVATORY PHOTOCHEMISTRY EXPERIMENT; CATALYTIC-REDUCTION TECHNIQUE; REMOTE FREE TROPOSPHERE; TRACE GAS MEASUREMENTS; REACTIVE NITROGEN; INTERCONTINENTAL TRANSPORT; SATELLITE-OBSERVATIONS; CARBON-MONOXIDE; SURFACE OZONE; NIWOT-RIDGE AB Measurements of NO, NO2, and NOy (total reactive nitrogen oxides) made at the Pico Mountain station, 38.47 degrees N, 28.40 degrees W, 2.2 km above sea level, from July 2002 to August 2005 are used to characterize the seasonal and diurnal variations of nitrogen oxides in the background lower free troposphere (FT) over the central North Atlantic Ocean. These observations reveal a well-defined seasonal cycle of nitrogen oxides (NOx = NO + NO2 and NOy), with higher mixing ratios during the summertime. Observed NOx and NOy levels are consistent with long-range transport of emissions, with significant removal en route to the measurement site. Larger summertime nitrogen oxides levels are attributed to boreal wildfire emissions and more efficient export and transport of NOy from eastern North America during that season. In addition, measurements of NOx and NOy obtained during in-cloud and cloud-free conditions are used to estimate PAN and HNO3 mixing ratios and examine the partitioning of the reactive nitrogen species. These estimates indicate that reactive nitrogen over the central North Atlantic lower FT largely exists in the form of PAN and HNO3 (similar to 80-90% of NOy) year-round. The composition of NOy shifts from dominance of PAN in winter-spring to dominance of HNO3 in summer-fall, as a result of changes in temperature and photochemistry over the region. A further comparison of the nitrogen oxides measurements with results from the global chemical transport model GEOS-Chem finds that simulated nitrogen oxides are significantly larger than the observations. C1 [Li, Q. B.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Martin, M. Val; Honrath, R. E.; Owen, R. C.] Michigan Technol Univ, Dept Civil & Environm Engn, Houghton, MI 49931 USA. RP Martin, MV (reprint author), Harvard Univ, Sch Engn & Appl Sci, Pierce 193,29 Oxford St, Cambridge, MA 02138 USA. EM mvalmart@seas.harvard.edu; reh@mtu.edu; rcowen@mtu.edu RI Val Martin, Maria/D-6955-2011; Chem, GEOS/C-5595-2014 FU NOAA, Office of Global Programs [NA16GP1658, NA86GP0325, NA03OAR4310002]; National Science Foundation [ATM-0215843, ATM-0535486, INT-0110397]; Azores Cooperative Initiative Program USDA [58-3625-5-127]; Azores Regional Secretariat for Science and Technology [M1.2.1/I/006/2005, M1.2.1/I/001/2008, M1.2.1/I/002/2008]; Program INTER-REG IIIB, Azores, Madeira; Canarias [IIIB-05/MAC/2.3/A1]; NASA's Atmospheric Composition Program FX This work was supported by NOAA, Office of Global Programs grants NA16GP1658, NA86GP0325, and NA03OAR4310002; the National Science Foundation grants ATM-0215843, ATM-0535486, and INT-0110397; Azores Cooperative Initiative Program USDA grant 58-3625-5-127; Azores Regional Secretariat for Science and Technology ( project M1.2.1/I/006/2005, project M1.2.1/I/001/2008, and project M1.2.1/I/002/2008); and Program INTER-REG IIIB, Azores, Madeira, and Canarias ( project CLIMARCOST FEDER-INTERREG IIIB-05/MAC/2.3/A1). Q. B. Li's research is performed at the Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA and was supported in part by NASA's Atmospheric Composition Program under P. DeCola. NR 81 TC 11 Z9 12 U1 1 U2 14 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 SEP 6 PY 2008 VL 113 IS D17 AR D17307 DI 10.1029/2007JD009688 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 345MK UT WOS:000259000700001 ER PT J AU van der Werf, GR Randerson, JT Giglio, L Gobron, N Dolman, AJ AF van der Werf, Guido R. Randerson, James T. Giglio, Louis Gobron, Nadine Dolman, A. J. TI Climate controls on the variability of fires in the tropics and subtropics SO GLOBAL BIOGEOCHEMICAL CYCLES LA English DT Article ID NOAA-AVHRR DATA; SOUTHERN-OSCILLATION; SAVANNA ECOSYSTEMS; NORTHERN AUSTRALIA; RAIN-FORESTS; EL-NINO; MODIS; EMISSIONS; SATELLITE; AMAZON AB In the tropics and subtropics, most fires are set by humans for a wide range of purposes. The total amount of burned area and fire emissions reflects a complex interaction between climate, human activities, and ecosystem processes. Here we used satellite-derived data sets of active fire detections, burned area, precipitation, and the fraction of absorbed photosynthetically active radiation (fAPAR) during 1998-2006 to investigate this interaction. The total number of active fire detections and burned area was highest in areas that had intermediate levels of both net primary production (NPP; 500-1000 g C m(-2) year(-1)) and precipitation (1000-2000 mm year(-1)), with limits imposed by the length of the fire season in wetter ecosystems and by fuel availability in drier ecosystems. For wet tropical forest ecosystems we developed a metric called the fire-driven deforestation potential (FDP) that integrated information about the length and intensity of the dry season. FDP partly explained the spatial and interannual pattern of fire-driven deforestation across tropical forest regions. This climate-fire link in combination with higher precipitation rates in the interior of the Amazon suggests that a negative feedback on fire-driven deforestation may exist as the deforestation front moves inward. In Africa, compared to the Amazon, a smaller fraction of the tropical forest area had FDP values sufficiently low to prevent fire use. Tropical forests in mainland Asia were highly vulnerable to fire, whereas forest areas in equatorial Asia had, on average, the lowest FDP values. FDP and active fire detections substantially increased in forests of equatorial Asia, however, during El Nino periods. In contrast to these wet ecosystems we found a positive relationship between precipitation, fAPAR, NPP, and active fire detections in arid ecosystems. This relationship was strongest in northern Australia and arid regions in Africa. Highest levels of fire activity were observed in savanna ecosystems that were limited neither by fuel nor by the length of the fire season. However, relations between annual precipitation or drought extent and active fire detections were often poor here, hinting at the important role of other factors, including land managers, in controlling spatial and temporal variability of fire. C1 [van der Werf, Guido R.; Dolman, A. J.] Vrije Univ Amsterdam, Fac Earth & Life Sci, Dept Hydrol & Geoenvironm Sci, NL-1081 HV Amsterdam, Netherlands. [Giglio, Louis] Sci Syst & Applicat Inc, Lanham, MD 20706 USA. [Gobron, Nadine] European Commiss Joint Res Ctr, Global Environm Monitoring Unit, Inst Environm & Sustainabil, I-21027 Ispra, VA, Italy. [Randerson, James T.] Univ Calif Irvine, Dept Earth Syst Sci, Irvine, CA 92697 USA. [Giglio, Louis] NASA, Goddard Space Flight Ctr, Sci Syst & Applicat Inc, Greenbelt, MD 20771 USA. RP van der Werf, GR (reprint author), Vrije Univ Amsterdam, Fac Earth & Life Sci, Dept Hydrol & Geoenvironm Sci, Boelelaan 1085, NL-1081 HV Amsterdam, Netherlands. EM guido.van.der.werf@falw.vu.nl RI van der Werf, Guido/M-8260-2016; OI van der Werf, Guido/0000-0001-9042-8630; Dolman, A.J./0000-0003-0099-0457 FU Netherlands Organization for Scientific Research; NASA [NNG04GK49G]; NSF [0628353] FX We thank G. J. Collatz for valuable comments and R. S. DeFries and D. C. Morton for sharing insights in fire dynamics in deforestation regions. G. R. v. d. W. was supported by a Veni grant from the Netherlands Organization for Scientific Research, J. T. R. was supported by NASA grant NNG04GK49G, and L. G. was supported by NSF grant 0628353. All data used to construct the graphs can be downloaded from http://www.geo.vu.nl/~gwerf/pubs/2008GBCfirecontrols. NR 63 TC 93 Z9 95 U1 2 U2 38 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0886-6236 EI 1944-9224 J9 GLOBAL BIOGEOCHEM CY JI Glob. Biogeochem. Cycle PD SEP 5 PY 2008 VL 22 IS 3 AR GB3028 DI 10.1029/2007GB003122 PG 13 WC Environmental Sciences; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Geology; Meteorology & Atmospheric Sciences GA 345ME UT WOS:000259000100001 ER PT J AU Bardeen, CG Toon, OB Jensen, EJ Marsh, DR Harvey, VL AF Bardeen, C. G. Toon, O. B. Jensen, E. J. Marsh, D. R. Harvey, V. L. TI Numerical simulations of the three-dimensional distribution of meteoric dust in the mesosphere and upper stratosphere SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID CHARGED DUST; SMOKE; PARTICLES; MODEL; AEROSOL; COAGULATION; ANALOGS; FLUX; SENSITIVITY; ATMOSPHERE AB Micrometeorites that ablate in the lower thermosphere and upper mesosphere are thought to recondense into nanometer-sized smoke particles and then coagulate into larger dust particles. Previous studies with one-dimensional models have determined that the meteoric dust size distribution is sensitive to the background vertical velocity and have speculated on the importance of the mesospheric meridional circulation to the dust spatial distribution. We conduct the first three-dimensional simulations of meteoric dust using a general circulation model with sectional microphysics to study the distribution and characteristics of meteoric dust in the mesosphere and upper stratosphere. We find that the mesospheric meridional circulation causes a strong seasonal pattern in meteoric dust concentration in which the summer pole is depleted and the winter pole is enhanced. This summer pole depletion of dust particles results in fewer dust condensation nuclei (CN) than has traditionally been assumed in numerical simulations of polar mesospheric clouds (PMCs). However, the total number of dust particles present is still sufficient to account for PMCs if smaller particles can nucleate to form ice than is conventionally assumed. During winter, dust is quickly transported down to the stratosphere in the polar vortex where it may participate in the nucleation of sulfate aerosols, the formation of the polar CN layer, and the formation of polar stratospheric clouds (PSCs). These predictions of the seasonal variation and resulting large gradients in dust concentration should assist the planning of future campaigns to measure meteoric dust. C1 [Bardeen, C. G.; Toon, O. B.] Univ Colorado, Atmospher & Space Phys Lab, Dept Atmospher & Ocean Sci, Boulder, CO 80309 USA. [Jensen, E. J.] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. [Marsh, D. R.] Natl Ctr Atmospher Res, Div Atmospher Chem, Boulder, CO 80307 USA. RP Bardeen, CG (reprint author), Univ Colorado, Atmospher & Space Phys Lab, Dept Atmospher & Ocean Sci, Campus Box 392, Boulder, CO 80309 USA. EM bardeenc@colorado.edu RI Marsh, Daniel/A-8406-2008 OI Marsh, Daniel/0000-0001-6699-494X FU National Science Foundation; NASA Earth System Science [NNG05GQ75J]; Aura [NNG06GE80G]; NSF [ATM0435713] FX The authors thank Guy Brasseur, Rolando Garcia, Doug Kinnison, Francis Vitt, and Stacy Walters of the National Center for Atmospheric Research for providing us with and supporting our use of the WACCM model. The National Center for Atmospheric Research is operated by the University Corporation for Atmospheric Research under the sponsorship of the National Science Foundation. Partial support for Charles Bardeen was provided by a NASA Earth System Science Fellowship grant NNG05GQ75J. Additional support for this project came from Aura grant NNG06GE80G and NSF grant ATM0435713. NR 47 TC 79 Z9 80 U1 0 U2 11 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 SEP 5 PY 2008 VL 113 IS D17 AR D17202 DI 10.1029/2007JD009515 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 345MH UT WOS:000259000400003 ER PT J AU Fried, A Olson, JR Walega, JG Crawford, JH Chen, G Weibring, P Richter, D Roller, C Tittel, F Porter, M Fuelberg, H Halland, J Bertram, TH Cohen, RC Pickering, K Heikes, BG Snow, JA Shen, HW O'Sullivan, DW Brune, WH Ren, XR Blake, DR Blake, N Sachse, G Diskin, GS Podolske, J Vay, SA Shetter, RE Hall, SR Anderson, BE Thornhill, L Clarke, AD McNaughton, CS Singh, HB Avery, MA Huey, G Kim, S Millet, DB AF Fried, Alan Olson, Jennifer R. Walega, James G. Crawford, Jim H. Chen, Gao Weibring, Petter Richter, Dirk Roller, Chad Tittel, Frank Porter, Michael Fuelberg, Henry Halland, Jeremy Bertram, Timothy H. Cohen, Ronald C. Pickering, Kenneth Heikes, Brian G. Snow, Julie A. Shen, Haiwei O'Sullivan, Daniel W. Brune, William H. Ren, Xinrong Blake, Donald R. Blake, Nicola Sachse, Glen Diskin, Glenn S. Podolske, James Vay, Stephanie A. Shetter, Richard E. Hall, Samuel R. Anderson, Bruce E. Thornhill, Lee Clarke, Antony D. McNaughton, Cameron S. Singh, Hanwant B. Avery, Melody A. Huey, Gregory Kim, Saewung Millet, Dylan B. TI Role of convection in redistributing formaldehyde to the upper troposphere over North America and the North Atlantic during the summer 2004 INTEX campaign SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID TROPICAL UPPER TROPOSPHERE; UNITED-STATES; HOX; CHEMISTRY; TRACE; PEROXIDES; INJECTION; NASHVILLE; RADICALS; IMPACT AB Measurements of formaldehyde (CH2O) from a tunable diode laser absorption spectrometer (TDLAS) were acquired onboard the NASA DC-8 aircraft during the summer 2004 INTEX-NA campaign to test our understanding of convection and CH2O production mechanisms in the upper troposphere ( UT, 6-12 km) over continental North America and the North Atlantic Ocean. The present study utilizes these TDLAS measurements and results from a box model to ( 1) establish sets of conditions by which to distinguish "background'' UT CH2O levels from those perturbed by convection and other causes; ( 2) quantify the CH2O precursor budgets for both air mass types; (3) quantify the fraction of time that the UT CH2O measurements over North America and North Atlantic are perturbed during the summer of 2004; ( 4) provide estimates for the fraction of time that such perturbed CH2O levels are caused by direct convection of boundary layer CH2O and/or convection of CH2O precursors; ( 5) assess the ability of box models to reproduce the CH2O measurements; and ( 6) examine CH2O and HO2 relationships in the presence of enhanced NO. Multiple tracers were used to arrive at a set of UT CH2O background and perturbed air mass periods, and 46% of the TDLAS measurements fell within the latter category. In general, production of CH2O from CH4 was found to be the dominant source term, even in perturbed air masses. This was followed by production from methyl hydroperoxide, methanol, PAN-type compounds, and ketones, in descending order of their contribution. At least 70% to 73% of the elevated UT observations were caused by enhanced production from CH2O precursors rather than direct transport of CH2O from the boundary layer. In the presence of elevated NO, there was a definite trend in the CH2O measurement-model discrepancy, and this was highly correlated with HO2 measurement - model discrepancies in the UT. C1 [Fried, Alan; Walega, James G.; Weibring, Petter; Richter, Dirk] Natl Ctr Atmospher Res, Earth Observing Lab, Boulder, CO 80303 USA. [Olson, Jennifer R.; Crawford, Jim H.; Chen, Gao; Sachse, Glen; Diskin, Glenn S.; Vay, Stephanie A.; Anderson, Bruce E.; Thornhill, Lee; Avery, Melody A.] NASA, Langley Res Ctr, Hampton, VA 23681 USA. [Roller, Chad] Ekips Technol Inc, Norman, OK 73069 USA. [Tittel, Frank] Rice Univ, Dept Elect & Comp Engn, Houston, TX 77005 USA. [Porter, Michael; Fuelberg, Henry; Halland, Jeremy] Florida State Univ, Dept Meteorol, Tallahassee, FL 32306 USA. [Bertram, Timothy H.; Cohen, Ronald C.] Univ Calif Berkeley, Dept Chem, Berkeley, CA 94705 USA. [Pickering, Kenneth] NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. [Heikes, Brian G.; Shen, Haiwei] Univ Rhode Isl, Grad Sch Oceanog, Ctr Atmospher Chem Studies, Narragansett, RI 02882 USA. [Snow, Julie A.] Slippery Rock Univ, Dept Geog Geol & Environm, Slippery Rock, PA 16057 USA. [O'Sullivan, Daniel W.] USN Acad, Dept Chem, Annapolis, MD 21402 USA. [Brune, William H.; Ren, Xinrong] Penn State Univ, Dept Meteorol, University Pk, PA 16802 USA. [Podolske, James; Singh, Hanwant B.] NASA, Ames Res Ctr, Atmospher Sci Branch, Moffett Field, CA 94035 USA. [Blake, Donald R.; Blake, Nicola] Univ Calif Irvine, Dept Chem, Irvine, CA 92697 USA. [Shetter, Richard E.; Hall, Samuel R.] NCAR, Div Atmospher Chem, Boulder, CO USA. [Clarke, Antony D.; McNaughton, Cameron S.] Univ Hawaii, Manoa, HI USA. [Huey, Gregory; Kim, Saewung] Georgia Inst Technol, Sch Earth & Atmospher Sci, Atlantic, GA 30332 USA. [Millet, Dylan B.] Harvard Univ, Cambridge, MA 02138 USA. [Bertram, Timothy H.; Cohen, Ronald C.] Univ Calif Irvine, Dept Earth & Planetary Sci, Berkeley, CA 94705 USA. RP Fried, A (reprint author), Natl Ctr Atmospher Res, Earth Observing Lab, 3450 Mitchell Lane, Boulder, CO 80303 USA. EM fried@ucar.edu RI Cohen, Ronald/A-8842-2011; Ren, Xinrong/B-2229-2010; Kim, Saewung/E-4089-2012; Pickering, Kenneth/E-6274-2012; Millet, Dylan/G-5832-2012; Crawford, James/L-6632-2013; Ren, Xinrong/E-7838-2015 OI Cohen, Ronald/0000-0001-6617-7691; Crawford, James/0000-0002-6982-0934; Ren, Xinrong/0000-0001-9974-1666 FU National Aeronautics and Space Administration's Global Tropospheric Experiment; NASA Atmospheric Chemistry Modeling and Analysis Program FX The National Center for Atmospheric Research is operated by the University Corporation for Atmospheric Research under the sponsorship of the National Science Foundation. This research was supported by funds from the National Aeronautics and Space Administration's Global Tropospheric Experiment. The authors specifically wish to acknowledge the NASA DC-8 staff and crew for all their valuable support and assistance and Mary Barth, Chris Cantrell, and John Orlando at NCAR for valuable discussions. The GEOS- Chem model is managed by the Atmospheric Chemistry Modeling group at Harvard University with support from the NASA Atmospheric Chemistry Modeling and Analysis Program. NR 37 TC 17 Z9 17 U1 1 U2 16 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 SEP 5 PY 2008 VL 113 IS D17 AR D17306 DI 10.1029/2007JD009760 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 345MH UT WOS:000259000400004 ER PT J AU Harvey, VL Randall, CE Manney, GL Singleton, CS AF Harvey, V. Lynn Randall, Cora E. Manney, Gloria L. Singleton, Cynthia S. TI Low-ozone pockets observed by EOS-MLS SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID STRATOSPHERIC EP FLUX; POLAR VORTEX; SOUTHERN-HEMISPHERE; METEOROLOGICAL REGIMES; INTERANNUAL VARIATIONS; NORTHERN MIDLATITUDES; WINTER STRATOSPHERE; POTENTIAL VORTICITY; AURA SATELLITE; COLUMN OZONE AB Earth Observing System (EOS) Microwave Limb Sounder (MLS) observations of ozone are analyzed along with meteorological data from the Met Office using a new automated algorithm to detect low-ozone pockets (LOPs) in stratospheric anticyclones. The algorithm is illustrated with a case study, and all LOPs identified in over 3 years of MLS data are shown. Daily averaged LOP ozone mixing ratios are 5-30% lower than ozone mixing ratios located directly outside a LOP. In the middle stratosphere, near 50 degrees latitude and the Date Line, large LOPs are identified on over 60% of Northern Hemisphere (NH) winter and 50% of Southern Hemisphere (SH) spring days. This suggests that a LOP is present in the Aleutian and Australian anticyclones nearly all the time during these seasons. Ozone reductions in the heart of the LOPs are typically about 20% (10%) in the NH ( SH). Thus the LOP contribution to seasonal ozone loss in the anticyclones is estimated at up to similar to 12% in NH winter and similar to 5% in SH spring. Average total column ozone loss from individual LOPs is estimated at similar to 3-6%. C1 [Harvey, V. Lynn; Randall, Cora E.; Singleton, Cynthia S.] Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80309 USA. [Manney, Gloria L.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Manney, Gloria L.] New Mexico Inst Min & Technol, Dept Phys, Socorro, NM 87801 USA. RP Harvey, VL (reprint author), Univ Colorado, Atmospher & Space Phys Lab, Campus Box 392, Boulder, CO 80309 USA. EM lynn.harvey@lasp.colorado.edu RI Randall, Cora/L-8760-2014 OI Randall, Cora/0000-0002-4313-4397 FU NASA [NNG06GI24G, NNG04GF39G] FX We appreciate comments made by three anonymous reviewers that improved the quality of this manuscript. We would like to thank colleagues at the United Kingdom Meteorological Office for producing the MetO analyses. We thank the MLS instrument science team for the satellite data. We would also like to thank the Distributed Active Archive Center at the Goddard Space Flight Center and the British Atmospheric Data Centre for distributing the data. Work at the Jet Propulsion Laboratory, California Institute of Technology was done under contract with the National Aeronautics and Space Administration. This work was supported by NASA grants NNG06GI24G and NNG04GF39G. NR 47 TC 10 Z9 10 U1 0 U2 0 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 SEP 5 PY 2008 VL 113 IS D17 AR D17112 DI 10.1029/2007JD009181 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 345MH UT WOS:000259000400002 ER PT J AU Morgan, DD Gurnett, DA Kirchner, DL Fox, JL Nielsen, E Plaut, JJ AF Morgan, D. D. Gurnett, D. A. Kirchner, D. L. Fox, J. L. Nielsen, E. Plaut, J. J. TI Variation of the Martian ionospheric electron density from Mars Express radar soundings SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID GLOBAL SURVEYOR; MONOCHROMATIC RADIATION; GRAZING-INCIDENCE; ROTATING EARTH; ATMOSPHERE; ABSORPTION; PEAK; PROFILES AB The Mars Advanced Radar for Subsurface and Ionospheric Sounding aboard Mars Express has been in operation for over 2 years. Between 14 August 2005 and 31 July 2007, we obtain 34,492 ionospheric traces, of which 14,060 yield electron density profiles and 12,291 yield acceptable fits to the Chapman ionospheric model. These results are used to study the Martian ionosphere under changing conditions: the presence or absence of solar energetic particles, solar EUV flux, season, solar zenith angle, and latitude. The 2-year average subsolar maximum electron density n(0) is 1.62 x 10(5) cm(-3), the average subsolar electron density altitude h(0) is 128.2 km, and the average neutral scale height H is 12.9 km. Solar energetic particle events are associated with a 6% increase in n(0), a 3 km decrease in h(0), and a 0-7 km decrease in H. The value of n(0) varies smoothly between 1.4 x 10(5) and 1.8 x 10(5) cm(-3), yielding d ln n(0)/d ln F10.7 = 0.30 +/- 0.4; h(0) varies between 115 and 135 km, while H remains relatively constant with EUV flux and season, in contrast with previous work. The value of h(0) decreases toward the terminator at low latitude but increases poleward during summer; H varies from 11 km, for solar zenith angle less than 40 degrees, to between 14 and 17 km near the terminator, depending on season. Near-peak temperatures vary between 220 K and 300 K, less variation than indicated by modeling, probably due to sampling near solar minimum. C1 [Morgan, D. D.; Gurnett, D. A.; Kirchner, D. L.] Univ Iowa, Dept Phys & Astron, Iowa City, IA 52242 USA. [Fox, J. L.] Wright State Univ, Dept Phys, Dayton, OH 45435 USA. [Nielsen, E.] Max Planck Inst Solar Syst Studies, D-37189 Katlenburg Lindau, Germany. [Plaut, J. J.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Morgan, DD (reprint author), Univ Iowa, Dept Phys & Astron, 718 Van Allen Hall, Iowa City, IA 52242 USA. EM david-morgan@uiowa.edu FU JPL [1224107] FX We would like to thank Zeynep Sagtas Bilki, Douglas Karkow, Andrew Kopf, Don Kirchner, and Julia Nelson for their meticulous work in processing a very large number of ionogram traces. We would also like to thank Paul Withers for help in accessing MGS Radio Science electron density profiles and Martin Patzold for providing Mars Express Radio Science electron density profiles. This work was supported under JPL contract 1224107. NR 47 TC 75 Z9 76 U1 1 U2 6 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 SEP 5 PY 2008 VL 113 IS A9 AR A09303 DI 10.1029/2008JA013313 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 345OC UT WOS:000259005100007 ER PT J AU Chappell, CR Huddleston, MM Moore, TE Giles, BL Delcourt, DC AF Chappell, C. R. Huddleston, M. M. Moore, T. E. Giles, B. L. Delcourt, D. C. TI Observations of the warm plasma cloak and an explanation of its formation in the magnetosphere SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID PITCH-ANGLE DISTRIBUTIONS; ENERGY ION FLUXES; SYNCHRONOUS ORBIT; POLAR WIND; DYNAMICS; ISEE-1; SHEET; ACCELERATION; DAYSIDE; MODEL AB Previous studies of the magnetospheric plasma populations have concentrated on the low-energy (1 eV) plasma of the plasmasphere, the more energetic (1-100 keV) plasma of the plasma sheet and ring current, and the high-energy (approximately MeV) plasma of the radiation belts. A compilation of satellite measurements over the past 30 years augmented by recent observations from the Polar-TIDE instrument has revealed a new perspective on a plasma population in the middle magnetosphere. This population consists of ions with energies of a few eV to greater than several hundred eV which display a characteristic bidirectional field-aligned pitch angle distribution. Measurements from the ATS, ISEE, SCATHA, DE, and POLAR satellites establish the characteristics of this "warm plasma cloak'' of particles that is draped over the nightside region of the plasmasphere and is blown into the morning and early afternoon dayside sector by the sunward convective wind in the magnetosphere. The satellite observations combined with the predictions of an ion trajectory model are used to describe the formation and dynamics of the warm plasma cloak. C1 [Delcourt, D. C.] IPSL, CNRS, Observ St Maur, Ctr Etude Environnements Terrestre & Planetaires, F-94107 St Maur, France. [Giles, B. L.] NASA Headquarters, Washington, DC 20546 USA. [Huddleston, M. M.] Vanderbilt Univ, Harpeth Hall Sch, Dept Phys & Astron, Nashville, TN 37235 USA. [Moore, T. E.] NASA, Goddard Space Flight Ctr, Heliophys Sci Div, Greenbelt, MD 20771 USA. [Chappell, C. R.] Vanderbilt Univ, Dept Phys & Astron, Vanderbilt Dyer Observ, Brentwood, TN 37027 USA. RP Chappell, CR (reprint author), Vanderbilt Univ, Dept Phys & Astron, Vanderbilt Dyer Observ, 1000 Oman Dr, Brentwood, TN 37027 USA. RI Moore, Thomas/D-4675-2012 OI Moore, Thomas/0000-0002-3150-1137 FU NASA [NNG04GB44G] FX This work involves collaborative research that has been done beginning at the NASA Marshall Space Flight Center more than 30 years ago. The authors are indebted to our many partners: Carl McIlwain and Sherman Deforest of UCSD for the ATS-5 and 6 data as well as Ed Shelley, Dick Johnson, Dick Sharp, and Bill Peterson at the Lockheed Palo Alto Research Laboratory for the ISEE, DE, and Polar data. The data analysis of Jim Horwitz, David Reasoner, Charles Baugher, Walter Lennartsson, and Tsugunobu Nagai has been pivotal in creating the early awareness of the warm plasma cloak region. We appreciate the support of the TIMAS, MFE, and TIDE instrument teams on Polar in making data available. One of us (C.R.C.) is grateful to NASA for the longstanding data analysis and instrument support that enabled the many collaborations between the Marshall Space Flight Center and the University of Alabama in Huntsville, the University of Texas at Dallas, and the University of Michigan and later with the NASA Goddard Space Flight Center, Vanderbilt University, and the Southwest Research Institute. This work was supported by NASA grant NNG04GB44G. NR 36 TC 30 Z9 30 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-SPACE JI J. Geophys. Res-Space Phys. PD SEP 4 PY 2008 VL 113 IS A9 AR A09206 DI 10.1029/2007JA012945 PG 21 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 345NX UT WOS:000259004600003 ER PT J AU Halekas, JS Delory, GT Lin, RP Stubbs, TJ Farrell, WM AF Halekas, J. S. Delory, G. T. Lin, R. P. Stubbs, T. J. Farrell, W. M. TI Lunar Prospector observations of the electrostatic potential of the lunar surface and its response to incident currents SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID DYNAMIC FOUNTAIN MODEL; SOLAR-WIND; PLASMA SHEATH; CHARGED DUST; SPACE; MOON; IONS; LEVITATION; EXOSPHERE; PLATE AB We present an analysis of Lunar Prospector Electron Reflectometer data from selected time periods using newly developed methods to correct for spacecraft potential and self-consistently utilizing the entire measured electron distribution to remotely sense the lunar surface electrostatic potential with respect to the ambient plasma. These new techniques enable the first quantitative measurements of lunar surface potentials from orbit. Knowledge of the spacecraft potential also allows accurate characterization of the downward-going electron fluxes that contribute to lunar surface charging, allowing us to determine how the lunar surface potential reacts to changing ambient plasma conditions. On the lunar night side, in shadow, we observe lunar surface potentials of similar to-100 V in the terrestrial magnetotail lobes and potentials of similar to-200 V to similar to-1 kV in the plasma sheet. In the lunar wake, we find potentials of similar to-200 V near the edges but smaller potentials in the central wake, where electron temperatures increase and secondary emission may reduce the magnitude of the negative surface potential. During solar energetic particle events, we see nightside lunar surface potentials as large as similar to-4 kV. On the other hand, on the lunar day side, in sunlight, we generally find potentials smaller than our measurement threshold of similar to 20 V, except in the plasma sheet, where we still observe negative potentials of several hundred volts at times, even in sunlight. The presence of significant negative charging in sunlight at these times, given the measured incident electron currents, implies either photocurrents from lunar regolith in situ two orders of magnitude lower than those measured in the laboratory or nonmonotonic near-surface potential variation with altitude. The functional dependence of the lunar surface potential on electron temperature in shadow implies somewhat smaller secondary emission yields from lunar regolith in situ than previously measured in the laboratory. These new techniques open the door for future studies of the variation of lunar surface charging as a function of temporal and spatial variations in input currents and as a function of location and material characteristics of the surface as well as comparisons to the increasingly sophisticated theoretical predictions now available. C1 [Halekas, J. S.; Delory, G. T.; Lin, R. P.] Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. [Stubbs, T. J.; Farrell, W. M.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Stubbs, T. J.] Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21250 USA. [Lin, R. P.] Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. RP Halekas, JS (reprint author), Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. EM jazzman@ssl.berkeley.edu RI Stubbs, Timothy/I-5139-2013; Farrell, William/I-4865-2013; OI Stubbs, Timothy/0000-0002-5524-645X; Halekas, Jasper/0000-0001-5258-6128 FU NASA [NNG06GJ23G, NNX07AG10G] FX This work was supported by NASA grants NNG06GJ23G and NNX07AG10G. NR 63 TC 53 Z9 54 U1 0 U2 4 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 SEP 4 PY 2008 VL 113 IS A9 AR A09102 DI 10.1029/2008JA013194 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 345NX UT WOS:000259004600006 ER PT J AU White, JW Hoogenboom, G Stackhouse, PW Hoell, JM AF White, Jeffrey W. Hoogenboom, Gerrit Stackhouse, Paul W., Jr. Hoell, James M. TI Evaluation of NASA satellite- and assimilation model-derived long-term daily temperature data over the continental US SO AGRICULTURAL AND FOREST METEOROLOGY LA English DT Article DE phenology; Triticum aestivum; decision support systems ID STATIONS; WHEAT; TIME; BIAS AB Agricultural research increasingly is expected to provide precise, quantitative information with an explicit geographic coverage. Limited availability of daily meteorological records often constrains efforts to provide such information through use of simulation models, spatial analysis, and related decision support tools. The Prediction Of Worldwide Energy Resources (NASA/POWER) project at the NASA Langley Research Center provides daily data globally for maximum and minimum temperatures and other weather variables on a 1 degrees latitude-longitude grid. The data are assembled from a range of products derived from satellite imagery, ground observations, windsondes, modeling and data assimilation. Daily temperature data from NASA/POWER for 1983 to 2004 for the continental US were compared with data of 855 individual ground stations from the National Weather Service Cooperative observer Program (COOP). Additionally, a wheat (Triticum aestivum L.) simulation model was used to compare predicted time to anthesis using the two data sources. Comparisons of daily maximum temperatures (T(max)) gave an r(2)-value of 0.88 (P < 0.001) and root-mean-squared error (RMSE) of 4.1 degrees C. For minimum temperature (T(min)), the r(2)-value was 0.88 (P < 0.001) and RMSE, 3.7 degrees C. Mean values of T(max), and T(min) from NASA/POWER were, respectively, 2.4 degrees C cooler and 1.1 degrees C warmer than the COOP data. Differences in temperature were least during summer months. When data were aggregated over periods of 8 days or more, the RMSE values declined to below 2.7 degrees C for T(max) and T(min). Simulations of time to anthesis with the two data sources were also strongly correlated (r(2) = 0.92, P < 0.001, RMSE = 14.5 d). Anthesis dates of winter wheat regions showed better agreement than southern, winter-grown spring wheat regions. The differences between the data sources were associated with differences in elevation, which in large part resulted from NASA/POWER data being based on mean elevations over a 1 degrees grid cells vs. COOP data corresponding to the elevation of specific stations. Additional sources of variation might include proximity to coastlines and differences in observation time, although these factors were not quantified. Overall, if mountainous and coastal regions are excluded, the NASA/POWER data appeared promising as a source of continuous daily temperature data for the USA for research and management applications concerned with scales appropriate to the 1 degrees coordinate grid. It further appeared that the POWER data could be improved by adjusting for elevation (lapse rate) effects, reducing seasonal bias, and refining estimation of actual maximum and minimum temperatures in diurnal cycles. Published by Elsevier B.V. C1 [White, Jeffrey W.] ARS, USDA, US Arid Land Agr Res Ctr, Maricopa, AZ 85239 USA. [Hoogenboom, Gerrit] Univ Georgia, Dept Biol & Agr Engn, Griffin, GA 30223 USA. [Stackhouse, Paul W., Jr.] NASA, Langley Res Ctr, Hampton, VA 23681 USA. [Hoell, James M.] Sci Syst & Applicat Inc, Hampton, VA 23666 USA. RP White, JW (reprint author), ARS, USDA, US Arid Land Agr Res Ctr, 21881 N Cardon Lane, Maricopa, AZ 85239 USA. EM jeffrey.white@ars.usda.gov RI Hoogenboom, Gerrit/F-3946-2010 OI Hoogenboom, Gerrit/0000-0002-1555-0537 FU NASA's Applied Science Rapid Prototype program; NASA Langley Research Center [NN07AAOOC]; Science Systems and Applications, Inc; US Department of Agriculture, Cooperative State Research, Education, and Extension Service (CSREES) FX We acknowledge the valuable assistance of Belinda Wernau in processing of the NOAA data. Portions of this work were funded by a grant from the NASA's Applied Science Rapid Prototype program through the NASA Langley Research Center under Contract NN07AAOOC with Science Systems and Applications, Inc. and a Special Research Grant from the US Department of Agriculture, Cooperative State Research, Education, and Extension Service (CSREES). NR 28 TC 19 Z9 19 U1 0 U2 30 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-1923 J9 AGR FOREST METEOROL JI Agric. For. Meteorol. PD SEP 3 PY 2008 VL 148 IS 10 BP 1574 EP 1584 DI 10.1016/j.agrformet.2008.05.017 PG 11 WC Agronomy; Forestry; Meteorology & Atmospheric Sciences SC Agriculture; Forestry; Meteorology & Atmospheric Sciences GA 355BL UT WOS:000259683600017 ER PT J AU Remsberg, EE Marshall, BT Garcia-Comas, M Krueger, D Lingenfelser, GS Martin-Torres, J Mlynczak, MG Russell, JM Smith, AK Zhao, Y Brown, C Gordley, LL Lopez-Gonzalez, MJ Lopez-Puertas, M She, CY Taylor, MJ Thompson, RE AF Remsberg, E. E. Marshall, B. T. Garcia-Comas, M. Krueger, D. Lingenfelser, G. S. Martin-Torres, J. Mlynczak, M. G. Russell, J. M., III Smith, A. K. Zhao, Y. Brown, C. Gordley, L. L. Lopez-Gonzalez, M. J. Lopez-Puertas, M. She, C. -Y. Taylor, M. J. Thompson, R. E. TI Assessment of the quality of the Version 1.07 temperature-versus-pressure profiles of the middle atmosphere from TIMED/SABER SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID HALOGEN OCCULTATION EXPERIMENT; MOLECULAR SPECTROSCOPIC DATABASE; LIMB INFRARED MONITOR; MESOSPHERIC OH MEINEL; NA LIDAR; ROTATIONAL TEMPERATURE; LOW-LATITUDES; MU-M; VALIDATION; EMISSION AB The quality of the retrieved temperature-versus-pressure (or T(p)) profiles is described for the middle atmosphere for the publicly available Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) Version 1.07 (V1.07) data set. The primary sources of systematic error for the SABER results below about 70 km are (1) errors in the measured radiances, ( 2) biases in the forward model, and (3) uncertainties in the corrections for ozone and in the determination of the reference pressure for the retrieved profiles. Comparisons with other correlative data sets indicate that SABER T(p) is too high by 1 - 3 K in the lower stratosphere but then too low by 1 K near the stratopause and by 2 K in the middle mesosphere. There is little difference between the local thermodynamic equilibrium (LTE) algorithm results below about 70 km from V1.07 and V1.06, but there are substantial improvements/differences for the non-LTE results of V1.07 for the upper mesosphere and lower thermosphere (UMLT) region. In particular, the V1.07 algorithm uses monthly, diurnally averaged CO2 profiles versus latitude from the Whole Atmosphere Community Climate Model. This change has improved the consistency of the character of the tides in its kinetic temperature (T-k). The T-k profiles agree with UMLT values obtained from ground-based measurements of column-averaged OH and O-2 emissions and of the Na lidar returns, at least within their mutual uncertainties. SABER T-k values obtained near the mesopause with its daytime algorithm also agree well with the falling sphere climatology at high northern latitudes in summer. It is concluded that the SABER data set can be the basis for improved, diurnal-to-interannual-scale temperatures for the middle atmosphere and especially for its UMLT region. C1 [Remsberg, E. E.; Mlynczak, M. G.] NASA, Langley Res Ctr, Sci Directorate, Hampton, VA 23681 USA. [Marshall, B. T.; Brown, C.; Gordley, L. L.; Thompson, R. E.] G&A Tech Software Inc, Newport News, VA 23606 USA. [Garcia-Comas, M.; Lopez-Gonzalez, M. J.; Lopez-Puertas, M.] CSIC, Inst Astrofis Andalucia, E-18008 Granada, Spain. [Krueger, D.; She, C. -Y.] Colorado State Univ, Dept Phys, Ft Collins, CO 80523 USA. [Lingenfelser, G. S.; Martin-Torres, J.] Sci Syst & Applicat Inc, Hampton, VA 23666 USA. [Russell, J. M., III] Hampton Univ, Ctr Atmospher Sci, Hampton, VA 23668 USA. [Smith, A. K.] Natl Ctr Atmospher Res, Boulder, CO 80307 USA. [Zhao, Y.; Taylor, M. J.] Utah State Univ, Ctr Atmospher & Space Sci, Logan, UT 84322 USA. RP Remsberg, EE (reprint author), NASA, Langley Res Ctr, Sci Directorate, 21 Langley Blvd,Mail Stop 401B, Hampton, VA 23681 USA. EM ellis.remsberg@nasa.gov RI Mlynczak, Martin/K-3396-2012; Lopez Puertas, Manuel/M-8219-2013; Garcia-Comas, Maya/E-4050-2014; Martin-Torres, Francisco Javier/G-6329-2015 OI Lopez Puertas, Manuel/0000-0003-2941-7734; Garcia-Comas, Maya/0000-0003-2323-4486; Martin-Torres, Francisco Javier/0000-0001-6479-2236 FU National Science Foundation (NSF); U. S. Air Force Office of Scientific Research (AFOSR); NASA/TIMED project [NNX07AB64G]; NSF/CEDAR projects [ATM- 00- 03171, ATM- 0545221]; Spanish project [ESP2004- 01556]; EC FEDER funds; National Science Foundation FX The authors recognize Chris Mertens, Artem Feofilov, Alexander Kutepov, Richard Picard, Jeremy Winick, and Peter Wintersteiner for their substantial contributions to the development and testing of the non- LTE temperature algorithms of SABERV1.06 and V1.07. The Rayleigh lidar data used in this publication were obtained as part of the Network for the Detection of Atmospheric Composition Change (NDACC) and are publicly available (see http:// www. ndacc. org). The Utah State MTM measurements were made as part of the Maui- MALT program, which is a jointly sponsored initiative between the National Science Foundation (NSF) and the U. S. Air Force Office of Scientific Research (AFOSR) and in coordination with TIMED/ SABER measurements. The sodium lidar data used in this publication were obtained with support from the NASA/TIMED project NNX07AB64G and the NSF/CEDAR projects ATM- 00- 03171 and ATM- 0545221. The IAA team was partially supported by the Spanish project ESP2004- 01556 and EC FEDER funds. Support for the assessment of the SABER temperature data sets was provided to the SABER project and administered by Charles Holmes (NASA/ Headquarters) and Richard Goldberg ( NASA/ GSFC). The National Center for Atmospheric Research is operated by the University Corporation for Atmospheric Research under sponsorship of the National Science Foundation, and it supports the work of A. K. S. NR 58 TC 183 Z9 187 U1 3 U2 18 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 SEP 3 PY 2008 VL 113 IS D17 AR D17101 DI 10.1029/2008JD010013 PG 27 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 345MF UT WOS:000259000200006 ER PT J AU Zent, AP Ichimura, AS Quinn, RC Harding, HK AF Zent, Aaron P. Ichimura, Andrew S. Quinn, Richard C. Harding, Heather K. TI The formation and stability of the superoxide radical (O(2)(-)) on rock-forming minerals: Band gaps, hydroxylation state, and implications for Mars oxidant chemistry SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID MARTIAN SOIL; PHOTOCATALYTIC OXIDATION; HYDROGEN-PEROXIDE; MERIDIANI-PLANUM; TITANIUM-DIOXIDE; UV-IRRADIATION; SURFACES; OXYGEN; REACTIVITY; ATMOSPHERE AB We have examined the generation and stability of O(2)(-) on TiO(2) and albite, a common Na feldspar. We were not able to produce thermally stable superoxide on albite, in contrast to the results of Yen et al., who reported the generation of O(2)(-) that was stable up to 200 degrees C on labradorite, another common feldspar. The superoxide radical did form under UV irradiation at 77 K on albite that was not dehydrated but decayed rapidly at room temperature. On dehydrated albite, no superoxide signal was observed. We studied the kinetics of O(2)(-) decomposition on hydrated albite and derived an activation energy, E(a) = 15.2 kJ/mol. Assuming pseudo first-order kinetics, a simple thermal model of Mars' regolith demonstrates that the surface O(2)(-) population does not go to zero overnight; superoxide extinction at the surface is only complete when the seasonal CO(2) cap covers the surface and surface photolysis is inhibited. Depending on the specific quantum efficiency of the e(-)/h(+) generation process, a finite, non-equilibrium population of O(2)(-) should be observable on Martian surface materials throughout the Martian year. However, on the basis of our inability to generate stable O(2)(-) on hydrated albite via direct UV irradiation, we do not believe that this mechanism is capable of explaining the O(2) release in the Viking Gas Exchange (GEx) results, since O(2) release in that case was observed even after samples had been stored for 143 sols in the dark at 10 degrees C, then heated to 145 degrees C for 3 hours. At least two other potential pathways to the generation of O(2)(-) are identified in this article. The first possibility is that metal oxides common on the Martian surface, particularly hematite, may be photoactive on Mars and play a role analogous to TiO(2) in surface catalysis. Secondly, we found that superoxide that formed during the sorption or drying of a 1% H(2)O(2) solution on TiO(2), and potentially other oxides seems to be stable indefinitely. C1 [Zent, Aaron P.] NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. [Ichimura, Andrew S.; Harding, Heather K.] San Francisco State Univ, Dept Chem & Biochem, San Francisco, CA 94132 USA. [Quinn, Richard C.] NASA, Ames Res Ctr, SETI Inst, Moffett Field, CA 94035 USA. RP Zent, AP (reprint author), NASA, Ames Res Ctr, Div Space Sci, MS 245-3, Moffett Field, CA 94035 USA. EM aaron.p.zent@nasa.gov FU NASA Exobiology; Astrobiology Research Program FX This research was support by the NASA Exobiology and Astrobiology Research Program. The authors would like to thank Frank Grunthaner, Albert Yen, Michael Hecht, Charles Bickel, Jean-Pierre Bibring, and Francois Poulet for material support, enlightening discussions, and critical insights. NR 55 TC 9 Z9 9 U1 0 U2 18 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 SEP 3 PY 2008 VL 113 IS E9 AR E09001 DI 10.1029/2007JE003001 PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 345NH UT WOS:000259003000001 ER PT J AU Grodent, D Bonfond, B Gerard, JC Radioti, A Gustin, J Clarke, JT Nichols, J Connerney, JEP AF Grodent, Denis Bonfond, Bertrand Gerard, Jean-Claude Radioti, Aikaterini Gustin, Jacques Clarke, John T. Nichols, Jonathan Connerney, John E. P. TI Auroral evidence of a localized magnetic anomaly in Jupiter's northern hemisphere SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID JOVIAN MAGNETOSPHERE; MIDDLE MAGNETOSPHERE; EQUATORIAL PLANE; SOLAR-WIND; UV AURORA; MODEL; OVAL; IO; FOOTPRINT; CURRENTS AB We analyze more than 1000 HST/Advanced Camera for Survey images of the ultraviolet auroral emissions appearing in the northern hemisphere of Jupiter. The auroral footprints of Io, Europa, and Ganymede form individual footpaths, which are fitted with three reference contours. The satellite footprints provide a convenient mapping between the northern Jovian ionosphere and the equatorial plane in the middle magnetosphere, independent of any magnetic field model. The VIP4 magnetic field model is in relatively good agreement with the observed footprint of Io. However, in the auroral kink sector, between the 80 degrees and 150 degrees System III meridians, the model significantly departs from the observation. One possible way to improve the agreement between the VIP4 model and the observed footprints is to include a magnetic anomaly. We suggest that this anomaly is characterized by a weakening of the surface magnetic field in the kink sector and by an added localized tilted dipole field. This dipole rotates with the planet at a depth of 0.245 R-J below the surface, and its magnitude is set to similar to 1% of Jupiter's dipole moment. The anomaly has a very limited influence on the magnetic field intensity in the equatorial plane between the orbits of Io and Ganymede. However, it is sufficient to bend the field lines near the high-latitude atmosphere and to reproduce the observed satellite ultraviolet footpaths. JUNO's in situ measurements will determine the structure of Jupiter's magnetic field in detail to expand on these results. C1 [Grodent, Denis; Bonfond, Bertrand; Gerard, Jean-Claude; Radioti, Aikaterini; Gustin, Jacques] Univ Liege, Lab Planetary & Atmospher Phys, B-4000 Cointe Ougree, Belgium. [Clarke, John T.; Nichols, Jonathan] Boston Univ, Ctr Space Phys, Boston, MA 02215 USA. [Connerney, John E. P.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Grodent, D (reprint author), Univ Liege, Lab Planetary & Atmospher Phys, Allee 6 Aout 17 B5c, B-4000 Cointe Ougree, Belgium. EM d.grodent@ulg.ac.be RI Nichols, Jonathan/F-5764-2010; Clarke, John/C-8644-2013; connerney, john/I-5127-2013; OI Nichols, Jonathan/0000-0002-8004-6409; Bonfond, Bertrand/0000-0002-2514-0187; GERARD, Jean-Claude/0000-0002-8565-8746 FU NASA [NAS5-26555]; Belgian Fund for Scientific Research (FNRS); European Space Agency; Space Telescope Science Institute to Boston University [HST-GO-10862.01-A] FX This work is based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute (STScI), which is operated by AURA, Inc., for NASA under contract NAS5-26555. DG, BB, JCG, AR, and JG are supported by the Belgian Fund for Scientific Research (FNRS) and by the PRODEX Program managed by the European Space Agency in collaboration with the Belgian Federal Science Policy Office. Work in Boston was supported by grant HST-GO-10862.01-A from the Space Telescope Science Institute to Boston University. Wolfgang Baumjohann thanks Jamesina Simpson and another reviewer for their assistance in evaluating this paper. NR 36 TC 34 Z9 34 U1 0 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 SEP 3 PY 2008 VL 113 IS A9 AR A09201 DI 10.1029/2008JA013185 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 345NV UT WOS:000259004400004 ER PT J AU Saluja, IS Williams, DR Woodard, D Kaczorowski, J Douglas, B Scarpa, PJ Comtois, JM AF Saluja, Inderpal S. Williams, David R. Woodard, Daniel Kaczorowski, Janusz Douglas, Ben Scarpa, Philip J. Comtois, Jean-Marc TI Survey of astronaut opinions on medical crewmembers for a mission to Mars SO ACTA ASTRONAUTICA LA English DT Article DE space exploration; autonomous medical care; telemedicine; remote medical care; physician-astronaut; crew medical officers; physicians; doctors; space emergencies ID SPACE STATION; ISSUES AB A Survey was submitted to all active members of the US Astronaut Corps to determine their opinions on the need for and qualifications of a crew medical officer (CMO) for a mission to Mars. The majority of respondents felt that health problems will occur during such a mission and that if there are more than four crewmembers, a physician should be included. Responses favored a physician with 4-6 years clinical experience, and a second CMO with paramedic-level training. Extensive training in emergency medicine, aerospace medicine. and internal medicine was considered desirable for a physician CMO, with more limited training in surgery, psychiatry, gynecology. dentistry, and other fields, as well as training in space analog environments on Earth. The astronauts felt that a physician would spend most of the his/her time, both during training and during the mission, in non-medical duties and must be fully capable Of Contributing other essential skills to the team. (c) 2008 Elsevier Ltd. All rights reserved. C1 [Saluja, Inderpal S.] McMaster Univ, Hamilton, ON L8S 4L8, Canada. [Saluja, Inderpal S.] Grand River Hosp, KW Joint Emergency Dept, Emergency Dept, Kitchener, ON N2G 1G3, Canada. [Williams, David R.] Lyndon B Johnson Space Ctr, Astronaut Off, Houston, TX 77058 USA. [Woodard, Daniel] NASA, Bionet Corp, Kennedy Space Ctr, FL 32899 USA. [Kaczorowski, Janusz] Univ British Columbia, Dept Family Practice, Vancouver, BC V6T 1Z3, Canada. [Douglas, Ben] Kings Coll London, Dept Aviat Med, London SE1 1UL, England. [Scarpa, Philip J.] NASA, Aerosp Med & Occupat Hlth Branch, Kennedy Space Ctr, FL 32899 USA. [Comtois, Jean-Marc] John H Chapman Space Ctr, St Hubert, PQ J3Y 8Y9, Canada. RP Saluja, IS (reprint author), McMaster Univ, Hamilton, ON L8S 4L8, Canada. EM salujai@yahoo.ca FU Canadian Space Agency FX The authors would like to thank the Institutional Review Boards (Johnson Space Center and Kennedy Space Center) for providing expedient approval, and to the Canadian Space Agency for their sponsorship and support for the project. NR 19 TC 4 Z9 4 U1 0 U2 2 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 SEP PY 2008 VL 63 IS 5-6 BP 586 EP 593 DI 10.1016/j.actaastro.2008.05.002 PG 8 WC Engineering, Aerospace SC Engineering GA 340GA UT WOS:000258632900004 ER PT J AU Smith, SM Zwart, SR AF Smith, Scott M. Zwart, Sara R. TI Nutrition issues for space exploration SO ACTA ASTRONAUTICA LA English DT Article ID FLIGHT; HUMANS AB Optimal nutrition will be critical for crew members who embark on space exploration missions. Nutritional assessment provides an opportunity to ensure that crew members begin their missions in optimal nutritional status, to document changes in status during a mission, and to assess changes after landing to facilitate return of the crew to their normal status as soon as possible after landing. Nutritional assessment provides the basis for intervention, if it is necessary, to maintain optimal status throughout the mission. We report here our nutritional assessment of the US astronauts who participated in the first 12 International Space Station missions. (c) 2008 Published by Elsevier Ltd. C1 [Smith, Scott M.] NASA, Lyndon B Johnson Space Ctr, Human Adaptat & Countermeasures Div, Houston, TX 77058 USA. [Zwart, Sara R.] Univ Space Res Assoc, Houston, TX 77058 USA. RP Smith, SM (reprint author), NASA, Lyndon B Johnson Space Ctr, Human Adaptat & Countermeasures Div, Mail Code SK,2101 NASA Pkwy, Houston, TX 77058 USA. EM scott.m.smith@nasa.gov; sara.zwart-1@nasa.gov NR 8 TC 7 Z9 11 U1 2 U2 11 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 SEP PY 2008 VL 63 IS 5-6 BP 609 EP 613 DI 10.1016/j.actaastro.2008.04.010 PG 5 WC Engineering, Aerospace SC Engineering GA 340GA UT WOS:000258632900007 ER PT J AU Bruhn, FC Kratz, H Warell, J Lagerkvist, CI Kaznov, V Jones, JA Stenmark, L AF Bruhn, Fredrik C. Kratz, Henrik Warell, Johan Lagerkvist, Claes-Ingvar Kaznov, Viktor Jones, Jack A. Stenmark, Lars TI A preliminary design for a spherical inflatable microrover for planetary exploration SO ACTA ASTRONAUTICA LA English DT Article ID MODULES AB The Spherical Mobile Investigator for Planetary Surface (SMIPS) concept aims at making use of the latest developments within extreme miniaturization of space systems. The introduction of Microelectromechanical Systems (MEMSs) and higher level Multifunctional Microsystems (MMSs) design solutions gives the robot high performance per weight unit. The untraditional spherical shape makes it easily maneuverable and thus provides a platform for scientific investigations of interplanetary bodies. Preliminary investigations of the SMIPS concept show several advantages over conventional robots and rovers in maneuverability, coverage, size, and mass. A locomotion proof-of-concept has been Studied together with a new distributed on-board data system configuration. This paper discusses theoretical robot analysis, an overall concept, possible science, enabling technologies, and how to perform scientific investigations. A preliminary design of an inflatable multifunctional shell is proposed. (c) 2008 Elsevier Ltd. All rights reserved. C1 [Bruhn, Fredrik C.; Kratz, Henrik; Stenmark, Lars] Uppsala Univ, Dept Engn Sci, Angstrom Space Technol Ctr, S-75105 Uppsala, Sweden. [Warell, Johan; Lagerkvist, Claes-Ingvar] Uppsala Univ, Dept Astron & Space Phys, S-75105 Uppsala, Sweden. [Jones, Jack A.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Bruhn, FC (reprint author), Uppsala Univ, Dept Engn Sci, Angstrom Space Technol Ctr, S-75105 Uppsala, Sweden. EM fredrik.bruhn@angstrom.uu.se; henrik.kratz@angstrom.uu.se; johan.warell@astro.uu.se; classe@astro.uu.se; viktor.kaznov@rotundus.se; jack.a.jones@jpl.nasa.gov FU Swedish National Space Board [D195/02] FX The authors are grateful to the Swedish National Space Board (SNSB), and the European Space Agency (ESA) for their contributions. This work was supported in part by the Swedish National Space Board under Grant D195/02. Per Samuelsson is acknowledged for his work on different spherical rovers. NR 22 TC 13 Z9 13 U1 0 U2 2 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 SEP PY 2008 VL 63 IS 5-6 BP 618 EP 631 DI 10.1016/j.actaastro.2008.01.044 PG 14 WC Engineering, Aerospace SC Engineering GA 340GA UT WOS:000258632900009 ER PT J AU Griffin, M AF Griffin, Michael TI NASA: A glorious past ... and future SO AEROSPACE AMERICA LA English DT Editorial Material C1 NASA, Washington, DC 20546 USA. RP Griffin, M (reprint author), NASA, Washington, DC 20546 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 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 SEP PY 2008 VL 46 IS 9 BP 3 EP 3 PG 1 WC Engineering, Aerospace SC Engineering GA 346GQ UT WOS:000259057200001 ER PT J AU Harari, D Iliffe, S Kharicha, K Egger, M Gillmann, G Von Renteln-Kruse, W Beck, J Swift, C Stuck, A AF Harari, Danielle Iliffe, Steve Kharicha, Kalpa Egger, Matthias Gillmann, Gerhard Von Renteln-Kruse, W. Beck, John Swift, Cameron Stuck, Andreas TI Promotion of health in older people: a randomised controlled trial of health risk appraisal in British general practice SO AGE AND AGEING LA English DT Article DE health risk appraisal; health promotion; older; primary care; elderly ID ELDERLY-PEOPLE; QUESTIONNAIRE; FEASIBILITY; PREVENTION; DISABILITY; BEHAVIORS AB Background: there is inadequate evidence to support currently formulated NHS strategies to achieve health promotion and preventative care in older people through broad-based screening and assessment in primary care. The most extensively evaluated delivery instrument for this purpose is Health Risk Appraisal (HRA). This article describes a trial using HRA to evaluate the effect on health behaviour and preventative-care uptake in older people in NHS primary care. Methods: a randomised controlled trial was undertaken in three London primary care group practices. Functionally independent community-dwelling patients older than 65years (n=2,503) received a self-administered Health Risk Appraisal for Older Persons (HRA-O) questionnaire leading to computer-generated individualised written feedback to participants and general practitioners (GPs), integrated into practice information-technology (IT) systems. All primary care staff received training in preventative health in older people. The main outcome measures were self-reported health behaviour and preventative care uptake at 1-year follow-up. Results: of 2,503 individuals randomised, 2,006 respondents (80.1%) (intervention, n=940, control n=1,066) were available for analysis. Intervention group respondents reported slightly higher pneumococcal vaccination uptake and equivocal improvement in physical activity levels compared with controls. No significant differences were observed for any other categories of health behaviour or preventative care measures at 1-year follow-up. Conclusions: HRA-O implemented in this way resulted in minimal improvement of health behaviour or uptake of preventative care measures in older people. Supplementary reinforcement involving contact by health professionals with patients over and above routine clinical encounters may be a prerequisite to the effectiveness of IT-based delivery systems for health promotion in older people. C1 [Harari, Danielle] St Thomas Hosp, Dept Ageing & Hlth, Guys & St Thomas NHS Fdn Trust, London SE1 7EH, England. [Iliffe, Steve; Kharicha, Kalpa] UCL, Dept Primary Care & Populat Sci, London NW3 2PF, England. [Egger, Matthias; Gillmann, Gerhard] Univ Bern, Dept Social & Prevent Med, CH-3012 Bern, Switzerland. [Von Renteln-Kruse, W.] Albertinen Haus Geriatr Ctr, D-22459 Hamburg, Germany. [Beck, John] Langley Res Ctr, Los Angeles, CA 90272 USA. [Swift, Cameron] Kings Coll London, Kings Coll Hosp, Dept Hlth Care Elderly, Clin Age Res Unit, London SE5 9PJ, England. [Stuck, Andreas] Univ Bern, Insel & Ziegler Hosp, Dept Geriatr, CH-3001 Bern, Switzerland. RP Harari, D (reprint author), St Thomas Hosp, Dept Ageing & Hlth, Guys & St Thomas NHS Fdn Trust, London SE1 7EH, England. EM danielle.harari@kcl.ac.uk OI Iliffe, Stephen/0000-0003-2806-3997 NR 26 TC 29 Z9 29 U1 0 U2 8 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0002-0729 J9 AGE AGEING JI Age Ageing PD SEP PY 2008 VL 37 IS 5 BP 565 EP 571 DI 10.1093/ageing/afn150 PG 7 WC Geriatrics & Gerontology SC Geriatrics & Gerontology GA 343MX UT WOS:000258859300017 PM 18755784 ER PT J AU Liou, MS Chang, CH Nguyen, L Theofanous, TG AF Liou, Meng-Sing Chang, Chih-Hao Nguyen, Loc Theofanous, Theo G. TI How to solve compressible multifluid equations: A simple, robust, and accurate method SO AIAA JOURNAL LA English DT Article; Proceedings Paper CT AIAA 18th Computational Fluid Dynamics Conference CY JUN 25-28, 2007 CL Miami, FL SP Amer Inst Aeronaut & Astronaut ID 2-PHASE FLOW; 2-FLUID MODEL; SCHEME; AUSM; AUSM(+)-UP; SEQUEL AB Solving multifluid equations of compressible multiphase flows has proven extremely demanding because of some peculiar mathematical properties such as nonhyperbolicity, nonconservative form, and stiffness due to disparity in fluid properties and flow scales. This paper gives several new contributions toward addressing difficulties arising from these properties. We first consider the mathematical issues concerning nonhyperbolicity and nonconservative form and establish their effects on the stability and convergence of numerical solutions. Then we present a new numerical method that is simple to implement without the need of employing the eigenstructure of the equations, which would be difficult to find for a general class of fluids. We show that our method properly removes numerical difficulties associated with the multifluid equations and it is capable of robustly and accurately calculating phenomena involving material and shock discontinuities and interactions between them for a range of typical multiphase problems of one and two space dimensions. Finally, the paper is completed with new information for ensuring hyperbolicity by an interfacial-pressure representation. C1 [Liou, Meng-Sing] NASA, John H Glenn Res Ctr Lewis Field, Cleveland, OH 44135 USA. [Chang, Chih-Hao; Nguyen, Loc; Theofanous, Theo G.] Univ Calif Santa Barbara, Ctr Risk Studies & Safety, Santa Barbara, CA 93106 USA. RP Liou, MS (reprint author), NASA, John H Glenn Res Ctr Lewis Field, Cleveland, OH 44135 USA. EM Meng-Sing.Liou@grc.nasa.gov; chchang@cngr.ucsb.edu; loc@engr.ucsb.edu; theo@engr.ucsb.edu NR 25 TC 19 Z9 19 U1 0 U2 6 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 SEP PY 2008 VL 46 IS 9 BP 2345 EP 2356 DI 10.2514/1.34793 PG 12 WC Engineering, Aerospace SC Engineering GA 344JA UT WOS:000258921500021 ER PT J AU Weaver, PM Nenieth, MP AF Weaver, Paul M. Nenieth, Michael P. TI Improved design formulas for buckling of orthotropic plates under combined loading SO AIAA JOURNAL LA English DT Article; Proceedings Paper CT AIAA/ASME/ASCE/AHS/ASC 49th Structures Structural Dynamic, and Materials Conference CY APR 07-10, 2008 CL Schaumburg, IL SP AIAA, ASME, ASCE, AHS, ASC ID COMPOSITE PLATES; COMPRESSION C1 [Weaver, Paul M.] Univ Bristol, Bristol BS8 1TR, Avon, England. [Nenieth, Michael P.] NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Weaver, PM (reprint author), Univ Bristol, Bristol BS8 1TR, Avon, England. RI Weaver, Paul/D-5972-2011 OI Weaver, Paul/0000-0002-1905-4477 NR 22 TC 4 Z9 5 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 SEP PY 2008 VL 46 IS 9 BP 2391 EP 2396 DI 10.2514/1.37892 PG 6 WC Engineering, Aerospace SC Engineering GA 344JA UT WOS:000258921500027 ER PT J AU Jones, T AF Jones, Tom TI Disaster at a distant moon (Fred Haise) SO AMERICAN HERITAGE LA English DT Article C1 [Jones, Tom] NASA, Washington, DC 20546 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER HERITAGE SUBSCRIPTION DEPT PI NEW YORK PA FORBES BUILDING 60 FIFTH AVE, NEW YORK, NY 10011 USA SN 0002-8738 J9 AM HERITAGE JI Am. Herit. PD FAL PY 2008 VL 58 IS 5 BP 43 EP 45 PG 3 WC History SC History GA 344JL UT WOS:000258922800026 ER PT J AU Peterson, A Risin, SA Ramesh, GT Dasgupta, A Risin, D AF Peterson, Amanda Risin, Semyon A. Ramesh, Govinchiraian T. Dasgupta, Amitava Risin, Diana TI Pharmacokinetics of acetaminophen in hind limbs unloaded mice: A model system simulating the effects of low gravity on astronauts in space SO AMERICAN JOURNAL OF CLINICAL PATHOLOGY LA English DT Meeting Abstract CT 43rd Annual Meeting of the Academy-of-Clinical-Laboratory-Physicians-and-Scientists CY JUN 05-07, 2008 CL Philadelphia, PA SP Acad Clin Lab Phys & Sci C1 [Peterson, Amanda; Risin, Semyon A.; Dasgupta, Amitava] Univ Texas Hlth Sci Univ Houston, Houston, TX USA. [Ramesh, Govinchiraian T.] Texas So Univ, Houston, TX 77004 USA. [Risin, Diana] NASA Johnson Space Ctr, Houston, TX USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU AMER SOC CLINICAL PATHOLOGY PI CHICAGO PA 2100 W HARRISON ST, CHICAGO, IL 60612 USA SN 0002-9173 J9 AM J CLIN PATHOL JI Am. J. Clin. Pathol. PD SEP PY 2008 VL 130 IS 3 MA 7 BP 471 EP 472 PG 2 WC Pathology SC Pathology GA 338WA UT WOS:000258538900026 ER PT J AU Fried, A Diskin, G Weibring, P Richter, D Walega, JG Sachse, G Slate, T Rana, M Podolske, J AF Fried, A. Diskin, G. Weibring, P. Richter, D. Walega, J. G. Sachse, G. Slate, T. Rana, M. Podolske, J. TI Tunable infrared laser instruments for airborne atmospheric studies SO APPLIED PHYSICS B-LASERS AND OPTICS LA English DT Article; Proceedings Paper CT 1st International Conferene on Field Laser Applications in Industry and Research CY SEP 02-07, 2007 CL Florence, ITALY ID FORMALDEHYDE MEASUREMENTS; CARBON-MONOXIDE; SPECTROMETER; PERFORMANCE; SPECTROSCOPY; HYGROMETER; N2O; CH4 AB Tunable infrared laser-based instruments on airborne platforms have provided invaluable contributions to atmospheric studies over the past several decades. This paper presents an overview of some recent studies and developments using this approach that were presented at the 2007 Field Laser Applications in Industry and Research (FLAIR, http://www.inoa.it/flair/) conference in Florence, Italy. The present overview only covers select in situ absorption-based instruments that were presented in the airborne session at this conference. In no case are comprehensive details presented. These details can be found in the numerous references given. Additional approaches based upon cavity-enhanced and photoacoustic measurements, which are also making invaluable contributions in airborne atmospheric studies, are not discussed in this brief overview. C1 [Fried, A.; Weibring, P.; Richter, D.; Walega, J. G.] Natl Ctr Atmospher Res, Earth Observ Lab, Boulder, CO 80301 USA. [Diskin, G.] NASA, Langley Res Ctr, Hampton, VA 23665 USA. [Sachse, G.] Natl Inst Aerospace, Hampton, VA USA. [Slate, T.; Rana, M.] ATK Aerosp, Hampton, VA USA. [Podolske, J.] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Fried, A (reprint author), Natl Ctr Atmospher Res, Earth Observ Lab, Boulder, CO 80301 USA. EM fried@ucar.edu NR 25 TC 33 Z9 33 U1 0 U2 12 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0946-2171 EI 1432-0649 J9 APPL PHYS B-LASERS O JI Appl. Phys. B-Lasers Opt. PD SEP PY 2008 VL 92 IS 3 BP 409 EP 417 DI 10.1007/s00340-008-3136-x PG 9 WC Optics; Physics, Applied SC Optics; Physics GA 341HA UT WOS:000258703600014 ER PT J AU Herrera, M Chi, M Bonds, M Browning, ND Woolman, JN Kvaas, RE Harris, SF Rhiger, DR Hill, CJ AF Herrera, M. Chi, M. Bonds, M. Browning, N. D. Woolman, Joseph N. Kvaas, Robert E. Harris, Sean F. Rhiger, David R. Hill, Cory J. TI Atomic scale analysis of the effect of the SiO(2) passivation treatment on InAs/GaSb superlattice mesa sidewall SO APPLIED PHYSICS LETTERS LA English DT Article ID INFRARED DETECTORS; PHOTODIODES; WAVELENGTH AB We have analyzed by electron microscopy techniques the effect of the deposition of a SiO(2) passivation layer on an InAs/GaSb type-II superlattice (SL) mesa with applications as a photodetector. Our images reveal good conformal coverage by the SiO(2) upon an undulating edge of the SL mesa. However, we have observed scarce As clusters at the interface between the SL mesa and the passivation layer and some degree of oxidation of the mesa sidewall. The strong reduction in surface leakage currents demonstrates that the observed imperfections do not have a substantial detrimental effect on the passivation capabilities of the SiO(2) layer. (C) 2008 American Institute of Physics. C1 [Herrera, M.; Chi, M.; Bonds, M.; Browning, N. D.] Univ Calif Davis, Dept Chem Engn & Mat Sci, Davis, CA 95616 USA. [Chi, M.; Browning, N. D.] Lawrence Livermore Natl Lab, Chem Mat & Life Sci Directorate, Livermore, CA 94550 USA. [Woolman, Joseph N.; Kvaas, Robert E.; Harris, Sean F.; Rhiger, David R.] Raytheon Vis Syst, Goleta, CA 93117 USA. [Hill, Cory J.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Herrera, M (reprint author), Univ Calif Davis, Dept Chem Engn & Mat Sci, 1 Shields Ave, Davis, CA 95616 USA. EM miriam.herrera@uca.es RI Chi, Miaofang/Q-2489-2015; OI Chi, Miaofang/0000-0003-0764-1567; Herrera Collado, Miriam/0000-0002-2325-5941; Browning, Nigel/0000-0003-0491-251X FU European Union [MOIF-CF-2006-21423]; DOE [DE-FG02-03ER46057]; Missile Defense Agency FX This work was supported by a grant from the European Union under Contract No. MOIF-CF-2006-21423 and in part by DOE (Grant No. DE-FG02-03ER46057). Additional support was provided by the Missile Defense Agency under Meimei Tidrow. The material growth described here was carried out at the Jet Propulsion Laboratory, California Institute of Technology and was sponsored by the National Aeronautics and Space Administration. NR 10 TC 17 Z9 17 U1 0 U2 3 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 SEP 1 PY 2008 VL 93 IS 9 AR 093106 DI 10.1063/1.2977589 PG 3 WC Physics, Applied SC Physics GA 345DH UT WOS:000258975800057 ER PT J AU Haghighipour, N Jewitt, D AF Haghighipour, N. Jewitt, D. TI A region void of irregular satellites around Jupiter SO ASTRONOMICAL JOURNAL LA English DT Article DE celestial mechanics; methods : N body simulations; planets and satellites : general; solar system : general ID URANIAN SATELLITES; TIDAL EVOLUTION; REGULAR SATELLITES; GIANT PLANETS; CAPTURE; INCLINATION; RESONANCES; ASTEROIDS; SYSTEM; MODEL AB An interesting feature of the giant planets of our solar system is the existence of regions around these objects where no irregular satellites are observed. Surveys have shown that, around Jupiter, such a region extends from the outermost regular satellite Callisto to the vicinity of Themisto, the innermost irregular satellite. To understand the reason for the existence of such a satellite-void region, we have studied the dynamical evolution of Jovian irregulars by numerically integrating the orbits of several hundred test particles, distributed in a region between 30 and 80 Jupiter-radii, for different values of their semimajor axes, orbital eccentricities, and inclinations. As expected, our simulations indicate that objects in or close to the influence zones of the Galilean satellites become unstable because of interactions with Ganymede and Callisto. However, these perturbations cannot account for the lack of irregular satellites in the entire region between Callisto and Themisto. It is suggested that at distances between 60 and 80 Jupiter-radii, Ganymede and Callisto may have long-term perturbative effects, which may require the integrations to be extended to times much longer than 10 Myr. The interactions of irregular satellites with protosatellites of Jupiter at the time of the formation of Jovian regulars may also be a destabilizing mechanism in this region. We present the results of our numerical simulations and discuss their applicability to similar satellite void-regions around other giant planets. C1 [Haghighipour, N.] Univ Hawaii, Inst Astron, Honolulu, HI 96822 USA. Univ Hawaii, NASA, Astrobiol Inst, Honolulu, HI 96822 USA. RP Haghighipour, N (reprint author), Univ Hawaii, Inst Astron, 2680 Woodlawn Dr, Honolulu, HI 96822 USA. EM nader@ifa.hawaii.edu; jewitt@ifa.hawaii.edu NR 28 TC 4 Z9 4 U1 0 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0004-6256 J9 ASTRON J JI Astron. J. PD SEP PY 2008 VL 136 IS 3 BP 909 EP 918 DI 10.1088/0004-6256/136/3/909 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 338AS UT WOS:000258477800002 ER PT J AU Bernard, JP Reach, WT Paradis, D Meixner, M Paladini, R Kawamura, A Onishi, T Vijh, U Gordon, K Indebetouw, R Hora, JL Whitney, B Blum, R Meade, M Babler, B Churchwell, EB Engelbracht, CW For, BQ Misselt, K Leitherer, C Cohen, M Boulandger, F Frogel, JA Fukui, Y Gallagher, J Gorjian, V Harris, J Kelly, D Latter, WB Madden, S Markwick-Kemper, C Mizuno, A Mizuno, N Mould, J Nota, A Oey, MS Olsen, K Panagia, N Perez-Gonzalez, P Shibai, H Sato, S Smith, L Staveley-Smith, L Tielens, AGGM Ueta, T Van Dyk, S Volk, K Werner, M Zaritsky, D AF Bernard, Jean-Philippe Reach, William T. Paradis, Deborah Meixner, Margaret Paladini, Roberta Kawamura, Akiko Onishi, Toshikazu Vijh, Uma Gordon, Karl Indebetouw, Remy Hora, Joseph L. Whitney, Barbara Blum, Robert Meade, Marilyn Babler, Brian Churchwell, Ed B. Engelbracht, Charles W. For, Bi-Qing Misselt, Karl Leitherer, Claus Cohen, Martin Boulandger, Francois Frogel, Jay A. Fukui, Yasuo Gallagher, Jay Gorjian, Varoujan Harris, Jason Kelly, Douglas Latter, William B. Madden, Suzanne Markwick-Kemper, Ciska Mizuno, Akira Mizuno, Norikazu Mould, Jeremy Nota, Antonella Oey, M. S. Olsen, Knut Panagia, Nino Perez-Gonzalez, Pablo Shibai, Hiroshi Sato, Shuji Smith, Linda Staveley-Smith, Lister Tielens, A. G. G. M. Ueta, Toshiya Van Dyk, Schuyler Volk, Kevin Werner, Michael Zaritsky, Dennis TI Spitzer survey of the Large Magellanic Cloud, Surveying the Agents of a Galaxy's Evolution (sage). IV. Dust properties in the interstellar medium SO ASTRONOMICAL JOURNAL LA English DT Article DE galaxies : ISM; infrared : galaxies; infrared : ISM; ISM : abundances; ISM : clouds magellanic clouds ID MULTIBAND IMAGING PHOTOMETER; LOW-METALLICITY ENVIRONMENTS; NEAR-INFRARED CONTINUUM; MOLECULAR CLOUDS; SPACE-TELESCOPE; H-I; CO SURVEY; ABSOLUTE CALIBRATION; IRREGULAR GALAXIES; ALPHA ABSORPTION AB The goal of this paper is to present the results of a preliminary analysis of the extended infrared (IR) emission by dust in the interstellar medium ( ISM) of the Large Magellanic Cloud (LMC). We combine Spitzer Surveying the Agents of Galaxy Evolution ( SAGE) and Infrared Astronomical Satellite ( IRAS) data and correlate the infrared emission with gas tracers of Hi, CO, and H a. We present a global analysis of the infrared emission as well as detailed modeling of the spectral energy distribution ( SED) of a few selected regions. Extended emission by dust associated with the neutral, molecular, and diffuse ionized phases of the ISM is detected at all IR bands from 3.6 mu m to 160 mu m. The relative abundance of the various dust species appears quite similar to that in the Milky Way ( MW) in all the regions we have modeled. We construct maps of the temperature of large dust grains. The temperature map shows variations in the range 12.1-34.7 K, with a systematic gradient from the inner to outer regions, tracing the general distribution of massive stars and individual H II regions as well as showing warmer dust in the stellar bar. This map is used to derive the far-infrared ( FIR) optical depth of large dust grains. We find two main departures in the LMC with respect to expectations based on the MW: ( 1) excess mid-infrared (MIR) emission near 70 mu m, referred to as the 70 mu m excess, and ( 2) departures from linear correlation between the FIR optical depth and the gas column density, which we refer to as FIR excess emission. The 70 mu m excess increases gradually from the MW to the LMC to the Small Magellanic Cloud (SMC), suggesting evolution with decreasing metallicity. The excess is associated with the neutral and diffuse ionized gas, with the strongest excess region located in a loop structure next to 30 Dor. We show that the 70 mu m excess can be explained by a modification of the size distribution of very small grains with respect to that in the MW, and a corresponding mass increase of similar or equal to 13% of the total dust mass in selected regions. The most likely explanation is that the 70 mu m excess is due to the production of large very small grains (VSG) through erosion of larger grains in the diffuse medium. This FIR excess could be due to intrinsic variations of the dust/gas ratio, which would then vary from 4.6 to 2.3 times lower than the MW values across the LMC, but X-CO values derived from the IR emission would then be about three times lower than those derived from the Virial analysis of the CO data. We also investigate the possibility that the FIR excess is associated with an additional gas component undetected in the available gas tracers. Assuming a constant dust abundance in all ISM phases, the additional gas component would have twice the known H I mass. We show that it is plausible that the FIR excess is due to cold atomic gas that is optically thick in the 21 cm line, while the contribution by a pure H-2 phase with no CO emission remains a possible explanation. C1 [Bernard, Jean-Philippe; Paradis, Deborah] CESR, Toulouse, France. [Reach, William T.; Paladini, Roberta; Latter, William B.; Van Dyk, Schuyler] CALTECH, Spitzer Sci Ctr, Pasadena, CA 91125 USA. [Meixner, Margaret; Leitherer, Claus; Nota, Antonella; Panagia, Nino] Space Telescope Sci Inst, Baltimore, MD 21218 USA. [Kawamura, Akiko; Onishi, Toshikazu; Fukui, Yasuo; Mizuno, Akira; Mizuno, Norikazu; Shibai, Hiroshi; Sato, Shuji] Nagoya Univ, Dept Astrophys, Chikusa Ku, Nagoya, Aichi 46401, Japan. [Gordon, Karl; Engelbracht, Charles W.; For, Bi-Qing; Misselt, Karl; Harris, Jason; Kelly, Douglas; Olsen, Knut; Perez-Gonzalez, Pablo; Zaritsky, Dennis] Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. [Indebetouw, Remy; Markwick-Kemper, Ciska] Univ Virginia, Dept Astron, Charlottesville, VA 22903 USA. [Hora, Joseph L.] Harvard Smithsonian, CfA, Cambridge, MA 02138 USA. [Whitney, Barbara; Gallagher, Jay] Space Sci Inst, Boulder, CO 80301 USA. [Blum, Robert] Cerro Tololo Interamer Observ, La Serena, Chile. [Meade, Marilyn; Babler, Brian; Churchwell, Ed B.] Univ Wisconsin, Dept Astron, Madison, WI 53706 USA. [Cohen, Martin] Univ Calif Berkeley, Radio Astron Lab, Berkeley, CA 94720 USA. [Boulandger, Francois] Univ Paris 11, Inst Astrophs Spatiale, Orsay, France. [Frogel, Jay A.] AURA Inc, Washington, DC 20005 USA. [Gorjian, Varoujan; Werner, Michael] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Madden, Suzanne] CENS, Serv Astrophys, F-91191 Gif Sur Yvette, France. [Mould, Jeremy] Natl Opt Astron Observ, Tucson, AZ 85726 USA. [Oey, M. S.] Univ Michigan, Dept Astron, Ann Arbor, MI 48109 USA. [Smith, Linda] UCL, Dept Phys & Astron, London WC1E 6BT, England. [Staveley-Smith, Lister] CSIRO, Head Off, Melbourne, Vic 3001, Australia. [Tielens, A. G. G. M.; Ueta, Toshiya] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. [Volk, Kevin] No Operat Ctr, Gemini Observ, Hilo, HI 96720 USA. RP Bernard, JP (reprint author), CESR, Toulouse, France. RI Staveley-Smith, Lister/A-1683-2011; Kemper, Francisca/D-8688-2011; Perez-Gonzalez, Pablo/J-2871-2016; OI Staveley-Smith, Lister/0000-0002-8057-0294; Kemper, Francisca/0000-0003-2743-8240; Perez-Gonzalez, Pablo/0000-0003-4528-5639; Babler, Brian/0000-0002-6984-5752; Hora, Joseph/0000-0002-5599-4650; Reach, William/0000-0001-8362-4094; Van Dyk, Schuyler/0000-0001-9038-9950 NR 83 TC 107 Z9 107 U1 0 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-6256 EI 1538-3881 J9 ASTRON J JI Astron. J. PD SEP PY 2008 VL 136 IS 3 BP 919 EP 945 DI 10.1088/0004-6256/136/3/919 PG 27 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 338AS UT WOS:000258477800003 ER PT J AU Kastner, JH Thorndike, SL Romanczyk, PA Buchanan, CL Hrivnak, BJ Sahai, R Egan, M AF Kastner, Joel H. Thorndike, Stephen L. Romanczyk, Paul A. Buchanan, Catherine L. Hrivnak, Bruce J. Sahai, Raghvendra Egan, Michael TI The large magellanic cloud's top 250: Classification of the most luminous compact 8 mu m sources in the large magellanic cloud SO ASTRONOMICAL JOURNAL LA English DT Article DE circumstellar matter; infrared : stars; Magellanic Clouds; stars : AGB and post-AGB; stars : mass loss ID GIANT BRANCH STARS; SPITZER-SPACE-TELESCOPE; MASS-LOSS RATES; CARBON STARS; OH/IR STARS; LOCAL GROUP; RED SUPERGIANTS; MICRON SPECTRA; AGB STARS; DUST AB To ascertain the nature of the brightest compact mid-infrared (mid-IR) sources in the Large Magellanic Cloud (LMC), we have applied an updated version of Buchanan et al.'s Two Micron All Sky Survey (2MASS)-Midcourse Space Experiment (MSX) color classification system, which is based on the results of Spitzer Space Telescope spectroscopy, to a mid-IR (8 mu m) flux-limited sample of 250 LMC objects for which 2MASS and MSX photometry is available. The resulting 2MASS-MSX ("JHK8") color-based classifications of these sources, which constitute the most mid-IR-luminous objects in the LMC, were augmented, cross-checked, and corrected where necessary via a variety of independent means, such that only 46 sources retain tentative classifications and only 10 sources cannot be classified at all. The sample is found to consist primarily of carbon-rich asymptotic giant branch (AGB) stars (35%), red supergiants (RSGs) (18%), and compact HII regions (32%), with additional, small populations of oxygen-rich AGB stars (similar to 5%), dusty, early-type emission-line stars (similar to 3%), and foreground, O-rich AGB stars in the Milky Way (similar to 3%). The very large ratio of C-rich to O-rich objects among the luminous and heavily dust-enshrouded AGB stars in our LMC IR source sample is consistent with the hypothesis that carbon stars form easily in lower metallicity environments. We demonstrate that very luminous C-rich and O-rich AGB stars and RSGs, identified here primarily on the basis of their JHK8 colors, also appear as distinct clusters in Spitzer Infrared Array Camera (IRAC)/Multiband Imaging Photometer for Spitzer (MIPS) color-color diagrams. Thus, in principle, the infrared spectrograph (IRS)-based IR photometric classification techniques applied here to the LMC can be applied to any external galaxy whose most luminous IR point sources are detectable and resolvable by 2MASS and Spitzer. C1 [Kastner, Joel H.; Romanczyk, Paul A.; Buchanan, Catherine L.] Rochester Inst Technol, Ctr Imaging Sci, Rochester, NY 14623 USA. [Thorndike, Stephen L.] Univ Rochester, Dept Phys & Astron, Rochester, NY 14627 USA. [Hrivnak, Bruce J.] Valparaiso Univ, Dept Phys & Astron, Valparaiso, IN 46383 USA. [Sahai, Raghvendra] NASA, JPL, Pasadena, CA 91109 USA. [Egan, Michael] Natl Geospatial Intelligence Agcy, Reston, VA 20191 USA. RP Kastner, JH (reprint author), Univ Grenoble 1, CNRS, Astrophys Lab, BP 53, F-38041 Grenoble, France. EM jhk@cis.rit.edu; clb@unimelb.edu.au FU JPL/Caltech Spitzer Space Telescope General Observer [NMO710076/1265276, NMO710076/1264276]; NASA Long Term Space Astrophysics award [NMO 710651, 399.20.40.06] FX The authors thank Bill Forrest and the referee, Jacco van Loon, for their extensive and incisive comments on this manuscript. Support for this research was provided by JPL/Caltech Spitzer Space Telescope General Observer grant NMO710076/1265276 to R. I. T. and NMO710076/1264276 to Valparaiso University and JPL. R. S. acknowledges additional support from a NASA Long Term Space Astrophysics award (NMO 710651, 399.20.40.06). NR 40 TC 23 Z9 23 U1 0 U2 1 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 SEP PY 2008 VL 136 IS 3 BP 1221 EP 1241 DI 10.1088/0004-6256/136/3/1221 PG 21 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 338AS UT WOS:000258477800027 ER PT J AU Bauer, WH Gull, TR Bennett, PD AF Bauer, Wendy Hagen Gull, Theodore R. Bennett, Philip D. TI Spatial extension in the ultraviolet spectrum of VV Cephei SO ASTRONOMICAL JOURNAL LA English DT Article DE binaries : close; stars : individual (VV Cep); stars : winds, outflows; ultraviolet : stars ID WIND ACCRETION; BINARY STARS; ECLIPSE; NEBULAE AB Two-dimensional processing of Hubble Space Telescope/Space Telescope Imaging Spectrograph (HST/STIS) echelle spectra of the eclipsing M2 Iab + B binary system, VV Cep, has revealed extended emission in all 21 epochs observed, ranging from midtotality through the first quadrature. In the ultraviolet accessible to STIS (1150-3150 angstrom), essentially all observed photons originate from the hot component. In total eclipse, a pure emission spectrum is seen, with strong lines from lower levels up to similar to 2 eV cut by blue-shifted absorption in the M supergiant wind. Out of eclipse, a continuum is observed upon which a rich absorption spectrum of mostly neutral and singly-ionized iron group elements is superimposed. Out of eclipse, the strongest absorption features sit atop the emission profiles seen during eclipse. Far from eclipse, the neutral lines disappear, and the strongest of the remaining absorption lines develop complex inverse P-Cygni profiles. The continuum and spectrally extended blue wings of the inverse P-Cygni spectral lines show a spatial extension characteristic of the HST/STIS response to an unresolved source. However, the emission components of spectral lines lying longward of the blue-shifted wind absorption typically show flux extending beyond the unresolved hot component, implying formation over an extended region much larger than the size of the binary orbit. This extended line emission is believed to be formed by scattering of photons from the hot component's continuum by ions in ground and low-lying metastable levels in the extended wind of the M supergiant. Extension is observed out of eclipse for lines with lower levels up to approximately 4 eV, but the greatest degree of extension is observed for lines with lower levels less than 2 eV. Radial velocity differences across the spatially extended emission correlate with the aperture position angle, consistent with model predictions for wind flow in a binary system in which the wind outflow is comparable to the orbital velocity, and indicate an orbital plane oriented from + 11 degrees E of N ( receding) through -169 degrees (approaching). C1 [Bauer, Wendy Hagen] Wellesley Coll, Whitin Observ, Wellesley, MA 02481 USA. [Gull, Theodore R.] NASA, Goddard Space Flight Ctr, Astrophys Sci Div, Greenbelt, MD 20771 USA. [Bennett, Philip D.] Eureka Sci Inc, Oakland, CA 94602 USA. [Bennett, Philip D.] St Marys Univ, Dept Astron & Phys, Halifax, NS B3H 3C3, Canada. RP Bauer, WH (reprint author), Wellesley Coll, Whitin Observ, 106 Cent St, Wellesley, MA 02481 USA. EM wbauer@wellesley.edu; Theodore.R.Gull@nasa.gov; pbennett@ap.stmarys.ca RI Gull, Theodore/D-2753-2012 OI Gull, Theodore/0000-0002-6851-5380 FU Space Telescope Science Institute [NAS 5-26555]; National Sciences and Engineering Research Council (NSERC) of Canada FX We would like to thank an anonymous referee for suggestions which have improved the presentation of this paper. P. D. B. and W. H. B. wish to acknowledge support for General Observer Programs GO-7269, 8257, 8779, and 9231, provided by NASA through a grant from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. P. D. B. also received funding from the National Sciences and Engineering Research Council (NSERC) of Canada in support of a continuing radial velocity program at the Dominion Astrophysical Observatory. W. H. B. acknowledges support from Wellesley College and T. R. G. acknowledges research support from the HST Project Office at NASA's Goddard Space Flight Center. NR 19 TC 2 Z9 2 U1 0 U2 1 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 SEP PY 2008 VL 136 IS 3 BP 1312 EP 1324 DI 10.1088/0004-6256/136/3/1312 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 338AS UT WOS:000258477800031 ER PT J AU Dahlen, T Mobasher, B Jouvel, S Kneib, JP Ilbert, O Arnouts, S Bernstein, G Rhodes, J AF Dahlen, Tomas Mobasher, Bahram Jouvel, Stephanie Kneib, Jean-Paul Ilbert, Olivier Arnouts, Stephane Bernstein, Gary Rhodes, Jason TI Supernova acceleration probe: Investigating photometric redshift optimization SO ASTRONOMICAL JOURNAL LA English DT Article DE cosmology : observations; galaxies : distances and redshifts ID HUBBLE-SPACE-TELESCOPE; STAR-FORMING GALAXIES; DEEP FIELD; DARK ENERGY; CONSTRAINTS; EVOLUTION; COSMOS; DISCOVERIES; CALIBRATION; ULTRAVIOLET AB The aim of this paper is to investigate ways to optimize the accuracy of photometric redshifts for a Supernova Acceleration Probe (SNAP)-like mission. We focus on how the accuracy of the photometric redshifts depends on the magnitude limit and signal-to-noise ratio (S/N), wavelength coverage, and the number of filters and their shapes and observed galaxy type. We use simulated galaxy catalogs constructed to reproduce observed galaxy luminosity functions from the Great Observatories Origins Deep Survey and derive photometric redshifts using a template fitting method. By using a catalog that resembles real data, we can estimate the expected number density of galaxies for which photometric redshifts can be derived. We find that the accuracy of the photometric redshifts is strongly dependent on the S/N (i.e., S/N > 10 is needed for accurate photometric redshifts). The accuracy of the photometric redshifts is also dependent on galaxy type, with smaller scatter for earlier- type galaxies. Comparing results using different filter sets, we find that including the U-band and near-IR bands is important for decreasing the fraction of outliers, i.e., "catastrophic failures." Using broad overlapping filters with resolution similar to 4 gives better photometric redshifts compared to narrower filters (resolution greater than or similar to 5) with the same integration time. We find that filters with square response curves result in a slightly higher scatter, mainly due to a higher fraction of outliers at faint magnitudes. We also compare a 9-filter set to a 17-filter set, where we assume that the available exposure time per filter in the latter set is half that of the first set. We find that the 9-filter set gives more accurate redshifts for a larger number of objects and reaches higher redshift, while the 17-filter set gives better results at bright magnitudes. C1 [Dahlen, Tomas; Mobasher, Bahram] Space Telescope Sci Inst, Baltimore, MD 21218 USA. [Jouvel, Stephanie; Kneib, Jean-Paul; Ilbert, Olivier; Arnouts, Stephane] Observ Astron Marseille Prov, F-13376 Marseille, France. [Bernstein, Gary] Univ Penn, Dept Phys & Astron, Philadelphia, PA 19104 USA. [Rhodes, Jason] CALTECH, Pasadena, CA 91125 USA. [Rhodes, Jason] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Dahlen, T (reprint author), Space Telescope Sci Inst, 3700 San Martin Dr, Baltimore, MD 21218 USA. RI Kneib, Jean-Paul/A-7919-2015 OI Kneib, Jean-Paul/0000-0002-4616-4989 FU French Research Ministry [45500] FX This work has been partially supported by the grant awarded for the "EFIGI Project" (grant no. 45500) from the French Research Ministry. We thank the anonymous referee for valuable comments and suggestions. NR 39 TC 11 Z9 11 U1 1 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0004-6256 J9 ASTRON J JI Astron. J. PD SEP PY 2008 VL 136 IS 3 BP 1361 EP 1371 DI 10.1088/0004-6256/136/3/1361 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 338AS UT WOS:000258477800034 ER PT J AU Durech, J Vokrouhlicky, D Kaasalainen, M Weissman, P Lowry, SC Beshore, E Higgins, D Krugly, YN Shevchenko, VG Gaftonyuk, NM Choi, YJ Kowalski, RA Larson, S Warner, BD Marshalkina, AL Ibrahimov, MA Molotov, IE Michalowski, T Kitazato, K AF Durech, J. Vokrouhlicky, D. Kaasalainen, M. Weissman, P. Lowry, S. C. Beshore, E. Higgins, D. Krugly, Y. N. Shevchenko, V. G. Gaftonyuk, N. M. Choi, Y. -J. Kowalski, R. A. Larson, S. Warner, B. D. Marshalkina, A. L. Ibrahimov, M. A. Molotov, I. E. Michalowski, T. Kitazato, K. TI New photometric observations of asteroids (1862) Apollo and (25143) Itokawa - an analysis of YORP effect SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE minor planets, asteroids; methods : data analysis; techniques : photometric ID ANALYTIC THEORY; SPIN-STATE; HAYABUSA; 25143-ITOKAWA; MODEL; TORQUES AB Aims. Asteroid (1862) Apollo is one of two asteroids in which the YORP effect was detected. We carried out new photometric observations of Apollo in April 2007 to enlarge the time line and to derive a more precise shape and spin state model. We also observed another YORP-candidate, asteroid (25143) Itokawa, in December 2006 and January 2007 to obtain a longer time line. An estimation of the YORP strength on Itokawa based on its precise shape model from the Hayabusa mission predicted the deceleration to be already observable during the 2007 apparition. Methods. We used the lightcurve inversion method to model the shape and spin state of Apollo. For Itokawa, the shape and pole direction are known to a high degree of accuracy from the Hayabusa mission, so we used a modified version of lightcurve inversion with only two free parameters -the rotation period and its linear change in time. Results. The new model of Apollo confirms earlier results. The observed acceleration of Apollo's rotation rate is (5.5 +/- 1.2) x 10(-8) rad d(-2), which is in agreement with the theoretically predicted value. For Itokawa, the theoretical YORP value is sensitive to the resolution of the shape model and lies in the range from -2 to -3 x 10(-7) rad d(-2). This is inconsistent with results of lightcurve inversion that place an upper limit to the change of Itokawa's rotation rate similar to 1.5 x 10(-7) rad d(-2). C1 [Durech, J.; Vokrouhlicky, D.] Charles Univ Prague, Astron Inst, CR-18000 Prague, Czech Republic. [Kaasalainen, M.] Univ Helsinki, Rolf Nevanlinna Inst, Dept Math & Stat, FIN-00014 Helsinki, Finland. [Weissman, P.; Lowry, S. C.; Choi, Y. -J.] CALTECH, Jet Prop Lab, Div Sci, Pasadena, CA 91109 USA. [Beshore, E.; Kowalski, R. A.; Larson, S.] Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. [Higgins, D.] Hunters Hill Observ, Ngunnawal, ACT 2913, Australia. [Krugly, Y. N.; Shevchenko, V. G.] Kharkov Natl Univ, Inst Astron, UA-61022 Kharkov, Ukraine. [Gaftonyuk, N. M.] Crimean Astrophys Observ, UA-98680 Simeiz, Ukraine. [Choi, Y. -J.] Korea Astron & Space Sci Inst, Taejon 305348, South Korea. [Warner, B. D.] Palmer Div Observ, Colorado Springs, CO 80908 USA. [Marshalkina, A. L.; Ibrahimov, M. A.] Uzbek Acad Sci, Ulugh Beg Astron Inst, Tashkent 100052, Uzbekistan. [Molotov, I. E.] RAS, Keldysh Inst Appl Math, Moscow 125047, Russia. [Michalowski, T.] Adam Mickiewicz Univ Poznan, Astron Observ, PL-60286 Poznan, Poland. [Kitazato, K.] Univ Tokyo, Dept Earth & Planetary Sci, Bynkyo Ku, Tokyo 1130033, Japan. RP Durech, J (reprint author), Charles Univ Prague, Astron Inst, V Holesovickach 2, CR-18000 Prague, Czech Republic. EM durech@sirrah.troja.mff.cuni.cz RI Kaasalainen, Mikko/G-4236-2014; Shevchenko, Vasilij/H-1366-2011; Durech, Josef/C-5634-2017 OI Shevchenko, Vasilij/0000-0003-1000-223X; Durech, Josef/0000-0003-4914-3646 FU NASA; Leverhulme Trust; Polish Ministry of Science and Higher Education [N N203 302535] FX This work was supported in part by the NASA Planetary Astronomy Program and was performed in part at Queens University Belfast and the Jet Propulsion Laboratory under a contract with NASA. SCL also acknowledges support from the Leverhulme Trust. The work of T. M. was supported by the Polish Ministry of Science and Higher Education - grant N N203 302535. We thank the anonymous referee for important comments. NR 28 TC 31 Z9 31 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 SEP PY 2008 VL 488 IS 1 BP 345 EP 350 DI 10.1051/0004-6361:200809663 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 340NL UT WOS:000258652200042 ER PT J AU Gruszecki, M Murawski, K Ofman, L AF Gruszecki, M. Murawski, K. Ofman, L. TI Standing fast magnetoacoustic kink waves of solar coronal loops with field-aligned flow SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE magnetohydrodynamics (MHD); Sun : corona; Sun : oscillations ID MAGNETOSONIC WAVES; ALFVEN WAVES; OSCILLATIONS; PLUMES; TRACE AB Aims. We refer to the recent observational data of Hinode, which detected weakly- attenuated coronal loop oscillations in the presence of background flow (Ofman & Wang 2008, A& A, 482, L9). Vertical loop oscillations that lasted for three wave periods were reported with a wave period P = 113 +/- 2 s, attenuation time t = 560 +/- 260 s, and wave amplitude A(max) = 0.67 +/- 0.12 Mm. Ofman & Wang (2008) estimated the flow speed within the range of 74-123 km s(-1). We consider impulsively generated standing fast magnetoacoustic kink waves of a straight solar coronal slab with field- aligned internal flow. We aim to determine the influence of such flow on the spatial and temporal signatures of these waves. Methods. The time- dependent, ideal magnetohydrodynamic equations are solved numerically. Results. The numerical results show that as a result of wave scattering on inhomogeneous flow kink waves experience stronger attenuation than for a still plasma, while P remains weakly altered by this flow. Numerically evaluated values of Amax and P are close to the observational data. A value of t is about two times smaller than observed. C1 [Gruszecki, M.; Murawski, K.] Marie Curie Sklodowska Univ, Inst Phys, Grp Astrophys & Grav Theory, PL-20031 Lublin, Poland. [Ofman, L.] Catholic Univ Amer, NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Gruszecki, M (reprint author), Marie Curie Sklodowska Univ, Inst Phys, Grp Astrophys & Grav Theory, Ul Radziszewskiego 10, PL-20031 Lublin, Poland. EM marcingruszecki@wp.pl FU Polish Ministry of Science. L.O; NASA Sun-Earth Connection theory program, NASA [NNG06GI55G]; NRL [N00173-06-1-G033] FX The authors express their thanks to the referee for his/her stimulating comment. M.G.'s and K. M.'s work was supported by the grant for years 2007-2010 from the Polish Ministry of Science. L.O. is supported by NASA Sun-Earth Connection theory program, NASA grant NNG06GI55G, and NRL grant N00173-06-1-G033. Athena is a grid-based code for astrophysical gas dynamics being developed with support of the NSF Information Technology Research (ITR) program. The magnetohydrodynamics code used in this study was developed at the Princeton University by Tom Gardiner, Jim Stone, Peter Teuben and John Hawley with support of the NSF Information Technology Research program. NR 20 TC 15 Z9 15 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 SEP PY 2008 VL 488 IS 2 BP 757 EP 761 DI 10.1051/0004-6361:200809873 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 342BT UT WOS:000258760300041 ER PT J AU Jorda, L Lamy, PL Faury, G Weissman, P Barucci, MA Fornasier, S Lowry, S Toth, I Kuppers, M AF Jorda, L. Lamy, P. L. Faury, G. Weissman, P. Barucci, M. A. Fornasier, S. Lowry, S. Toth, I. Kueppers, M. TI Asteroid 2867 Steins - I. Photometric properties from OSIRIS/Rosetta and ground-based visible observations SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE minor planets,asteroids; techniques : photometric ID NARROW-ANGLE CAMERA; ROSETTA MISSION; SPACE-TELESCOPE; ASTEROIDS; 2867-STEINS; TARGET; 64-ANGELINA; 21-LUTETIA; OSIRIS AB Context. Asteroid 2867 Steins is the first target of the Rosetta space mission with a flyby scheduled in September 2008. Aims. An early characterization is needed to optimize the flyby parameters and the science operations and to maximize the scientific return. The aim of this article is to characterize the photometric properties of this asteroid. Methods. The asteroid was imaged with the Narrow Angle Camera ( NAC) of the Optical, Spectroscopic, and Infrared Remote Imaging System ( OSIRIS) during the cruise phase of the Rosetta spacecraft, at a phase angle of 41.7. significantly larger than achievable from Earth. It was continuously monitored over 24 h ( on 11 March 2006), thus covering four rotational periods, at a temporal cadence of 6 min. An accurate photometric calibration was obtained from the observations of a solar analog star, 16 Cyg B. Results. The light curve in the R photometric band of the Johnson- Kron- Cousins system has a mean value R( 1, 1, a = 41.7.) = 14.13 +/- 0.03 and an amplitude of 0.25 +/- 0.04 mag. The periodicity was analyzed with di. erent techniques yielding a mean value of the synodic rotational period of 6.054 +/- 0.003 h. By combining with ground- based observations obtained at di. erent phase angles, the phase function is constructed and characterized by a linear part having a phase coe. cient alpha = 0.025 +/- 0.001 mag/ deg and a mean value R( 1, 1, 0) = 13.10 +/- 0.04. In terms of the H- G formalism, the best fit photometric values are G = 0.35 +/- 0.05 and H = 12.84 +/- 0.07, but the resulting opposition surge of 0.25 mag, although typical of E- type asteroids, is not really constrained because of the lack of data at phase angles below 7.. Altogether the photometric properties of asteroid 2867 Steins ( phase function, color and albedo) indicate that it is a somewhat extreme E- type object, although it is known that this quite small population exhibits at least three di. erent surface mineralogies. C1 [Jorda, L.; Lamy, P. L.; Faury, G.; Toth, I.] Univ Aix Marseille 1, CNRS, UMR6110, Lab Astrophys Marseille, F-13388 Marseille 13, France. [Weissman, P.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Barucci, M. A.; Fornasier, S.] Observ Paris, LESIA, F-92195 Meudon, France. [Fornasier, S.] Univ Paris 07, F-75221 Paris 05, France. [Lowry, S.] Queens Univ Belfast, Sch Math & Phys, Belfast, Antrim, North Ireland. [Toth, I.] Konkoly Observ Budapest, H-1525 Budapest, Hungary. RP Jorda, L (reprint author), Univ Aix Marseille 1, CNRS, UMR6110, Lab Astrophys Marseille, 38 Rue Frederic Joliot Curie, F-13388 Marseille 13, France. EM laurent.jorda@oamp.fr NR 32 TC 11 Z9 11 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 SEP PY 2008 VL 487 IS 3 BP 1171 EP U152 DI 10.1051/0004-6361:20078994 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 335XO UT WOS:000258328100033 ER PT J AU Lamy, PL Kaasalainen, M Lowry, S Weissman, P Barucci, MA Carvano, J Choi, YJ Colas, F Faury, G Fornasier, S Groussin, O Hicks, MD Jorda, L Kryszczynska, A Larson, S Toth, I Warner, B AF Lamy, P. L. Kaasalainen, M. Lowry, S. Weissman, P. Barucci, M. A. Carvano, J. Choi, Y. -J. Colas, F. Faury, G. Fornasier, S. Groussin, O. Hicks, M. D. Jorda, L. Kryszczynska, A. Larson, S. Toth, I. Warner, B. TI Asteroid 2867 Steins - II. Multi-telescope visible observations, shape reconstruction, and rotational state SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE minor planets,asteroids; techniques : image processing ID SPACE-TELESCOPE; ROSETTA; 2867-STEINS; 21-LUTETIA; ASTEROIDS; STEINS AB Context. Asteroid 2867 Steins is the first target of the Rosetta space mission with a flyby scheduled in September 2008. Aims. An early physical characterization is needed to optimize the flyby parameters and the science operations, and to maximize the scientific return. The aim of this article is to characterize the shape and rotational state of this asteroid. Methods. We compile a set of 26 visible light curves whose phase angle coverage extends from 7.5. to 41.7., and perform their simultaneous inversion relying on convex modeling. Results. The full three-dimensional solution for asteroid 2867 Steins is rather spherical with axial ratios a/ b = 1.17 and a/ c = 1.25. The rotational state is characterized by a sidereal period of 6.04681 +/- 0.00002 h, and the pole direction defined by its ecliptic coordinates lambda approximate to 250. and beta approximate to -89 degrees has an uncertainty of about 5.. It is therefore almost exactly perpendicular to the ecliptic plane, and the viewing geometries are thus restricted to only +/- 20. about Steins' equator. Consequently, the shape model is not strongly constrained, and the polar flattening has an uncertainty of about 10%. Inversion is basically scale-free, and absolute scaling comes from a measurement of its thermal emission with the Spitzer Space Telescope ( Lamy et al. 2008, A& A, 487, 1187), yielding overall dimensions of 5.73 +/- 0.52, 4.95 +/- 0.45, and 4.58 +/- 0.41 km. C1 [Lamy, P. L.; Faury, G.; Groussin, O.; Jorda, L.; Toth, I.] Univ Aix Marseille 1, CNRS, UMR6110, Lab Astrophys Marseille, F-13388 Marseille 13, France. [Kaasalainen, M.] Univ Helsinki, Dept Math & Stat, FIN-00014 Helsinki, Finland. [Lowry, S.; Choi, Y. -J.; Hicks, M. D.] Queens Univ Belfast, Sch Math & Phys, Belfast, Antrim, North Ireland. [Lowry, S.; Weissman, P.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Barucci, M. A.; Fornasier, S.] Observ Paris, LESIA, F-92195 Meudon, France. [Colas, F.] Inst Mecan Celeste, F-75014 Paris, France. [Fornasier, S.] Univ Paris 07, F-75221 Paris 05, France. [Kryszczynska, A.] Adam Mickiewicz Univ Poznan, Astron Observ, PL-60286 Poznan, Poland. [Larson, S.] Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. [Toth, I.] Konkoly Observ Budapest, H-1525 Budapest, Hungary. [Warner, B.] Palmer Divide Observ, Colorado Springs, CO 80908 USA. RP Lamy, PL (reprint author), Univ Aix Marseille 1, CNRS, UMR6110, Lab Astrophys Marseille, 38 Rue Frederic Joliot Curie, F-13388 Marseille 13, France. EM philippe.lamy@oamp.fr RI Kaasalainen, Mikko/G-4236-2014; Ferreira Carvano, Jorge/I-4039-2016 OI Ferreira Carvano, Jorge/0000-0003-0670-639X NR 16 TC 21 Z9 21 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 SEP PY 2008 VL 487 IS 3 BP 1179 EP 1185 DI 10.1051/0004-6361:20078995 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 335XO UT WOS:000258328100034 ER PT J AU Ferry, M Rhodes, J Massey, R White, M Coe, D Mobasher, B AF Ferry, Matt Rhodes, Jason Massey, Richard White, Martin Coe, Dan Mobasher, Bahram TI Color, 3D simulated images with shapelets SO ASTROPARTICLE PHYSICS LA English DT Article DE Galaxies: fundamental parameters, statistics; Methods: statistical; Image simulations; Gravitational lensing ID WEAK LENSING MEASUREMENTS; GALAXIES; SPACE; SHEAR; EVOLUTION; COSMOS AB We present a method to simulate color, 3-dimensional images taken with a space-based observatory by building off of the established shapelets pipeline. The simulated galaxies exhibit complex morphologies, which are realistically correlated between, and include, known redshifts. The simulations are created using galaxies from the 4 optical and near-infrared bands (B, V, i and z) of the Hubble ultra Deep Field (UDF) as a basis set to model morphologies and redshift. We include observational effects such as sky noise and pixelization and can add astronomical signals of interest such as weak gravitational lensing. The realism of the simulations is demonstrated by comparing their morphologies to the original UDF galaxies and by comparing their distribution of ellipticities as a function of redshift and magnitude to wider HST COSMOS data. These simulations have already been useful for calibrating multicolor image analysis techniques and for better optimizing the design of proposed space telescopes. (C) 2008 Elsevier B.V. All rights reserved. C1 [Ferry, Matt; Rhodes, Jason; Coe, Dan] CALTECH, Pasadena, CA 91125 USA. [Ferry, Matt; White, Martin] Univ Calif Berkeley, Berkeley, CA 94720 USA. [Ferry, Matt; Rhodes, Jason; Coe, Dan] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Massey, Richard] Royal Observ, Edinburgh EH9 3HJ, Midlothian, Scotland. [Mobasher, Bahram] Univ Calif Riverside, Riverside, CA 92521 USA. RP Ferry, M (reprint author), CALTECH, 1200 E Calif Blvd, Pasadena, CA 91125 USA. EM mferry@astro.caltech.edu RI White, Martin/I-3880-2015 OI White, Martin/0000-0001-9912-5070 FU NASA [BEFS-399131.02.02.01.07] FX The authors thank the Caltech SURF program, the Berkeley Physics Undergraduate Research Scholars program, and the Jet Propulsion Laboratory, run under a contract with NASA by Caltech, for their support. We would also like to thank Richard Ellis for further support and enthusiasm regarding the project and Alexandre Refregier for his ideas and enthusiasm. The project would not have gotten started on the right path were it not for Will High's help. Thanks also to Peter Capak for useful insights in simultaneous detection with SExtractor. Dave Johnston provided the PSF for SNAP and was helpful in calibrating the measurements of a.,, Thanks also to Alexie Leauthaud for help in shear measurement. JR and MF were supported in part by NASA Grant BEFS-399131.02.02.01.07. NR 28 TC 8 Z9 8 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-6505 J9 ASTROPART PHYS JI Astropart Phys. PD SEP PY 2008 VL 30 IS 2 BP 65 EP 71 DI 10.1016/j.astropartphys.2008.07.001 PG 7 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 359YF UT WOS:000260023500004 ER PT J AU Wise, JH Abel, T AF Wise, John H. Abel, Tom TI How very massive metal-free stars start cosmological reionization SO ASTROPHYSICAL JOURNAL LA English DT Review DE cosmology : theory; galaxies : formation; intergalactic medium; stars : formation ID PROBE WMAP OBSERVATIONS; PRIMORDIAL HII-REGIONS; POPULATION III STARS; VERY-LOW METALLICITY; COLD DARK-MATTER; LY-ALPHA FOREST; RADIATIVE FEEDBACK; GALAXY FORMATION; HIGH-REDSHIFT; 1ST STARS AB The initial conditions and relevant physics for the formation of the earliest galaxies are well specified in the concordance cosmology. Using ab initio cosmological Eulerian adaptive mesh refinement radiation hydrodynamical calculations, we discuss how very massive stars start the process of cosmological reionization. The models include nonequilibrium primordial gas chemistry and cooling processes and accurate radiation transport in the case B approximation using adaptively ray-traced photon packages, retaining the time derivative in the transport equation. Supernova feedback is modeled by thermal explosions triggered at parsec scales. All calculations resolve the local Jeans length by at least 16 grid cells at all times and as such cover a spatial dynamic range of similar to 10(6). These first sources of reionization are highly intermittent and anisotropic and first photoionize the small-scale voids surrounding the halos they form in, rather than the dense filaments they are embedded in. As themerging objects form larger, dwarf-sized galaxies, the escape fraction of UV radiation decreases and the H II regions only break out on some sides of the galaxies, making them even more anisotropic. In three cases, SN blast waves induce star formation in overdense regions that were formed earlier from ionization front instabilities. These stars form tens of parsecs away from the center of their parent DM halo. Approximately five ionizing photons are needed per sustained ionization when star formation in 10(6) M-circle dot halos is dominant in the calculation. As the halos become larger than similar to 10(7)M(circle dot), the ionizing photon escape fraction decreases, which in turn increases the number of photons per ionization to 15-50, in calculations with stellar feedback only. Radiative feedback decreases clumping factors by 25% when compared to simulations without star formation and increases the average temperature of ionized gas to values between 3000 and 10,000 K. C1 [Wise, John H.; Abel, Tom] Stanford Univ, Kavli Inst Particle Astrophys & Cosmol, Menlo Pk, CA 94025 USA. RP Wise, JH (reprint author), NASA, Goddard Space Flight Ctr, Lab Observ & Cosmol, Greenbelt, MD 21114 USA. EM john.h.wise@nasa.gov FU NSFCAREER [AST 02-39709]; National Science Foundation [PHY05-51164] FX The quality and robustness of this paper was improved through the feedback of an anonymous referee. This work was supported by NSFCAREER award AST 02-39709 from the National Science Foundation and partially supported in part by the National Science Foundation under grant PHY05-51164. J. H. W. thanks Renyue Cen for helpful discussions. We benefited from fruitful conversations with Marcelo Alvarez. We are grateful for the continuous support from the computational team at SLAC. We benefited from the hospitality of KITP at UC Santa Barbara, where this work was completed. We performed these calculations on 16 processors of a SGI Altix 3700 Bx2 at KIPAC at Stanford University. NR 109 TC 55 Z9 55 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 SEP 1 PY 2008 VL 684 IS 1 BP 1 EP 17 DI 10.1086/590050 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 341QV UT WOS:000258730700001 ER PT J AU Kasliwal, MM Massey, R Ellis, RS Miyazaki, S Rhodes, J AF Kasliwal, Mansi M. Massey, Richard Ellis, Richard S. Miyazaki, Satoshi Rhodes, Jason TI A comparison of weak-lensing measurements from ground- and space-based facilities SO ASTROPHYSICAL JOURNAL LA English DT Article DE atmospheric effects; cosmology : observations; gravitational lensing; instrumentation : detectors ID EVOLUTION SURVEY COSMOS; LARGE-SCALE STRUCTURE; SQUARE DEGREE FIELD; DARK-MATTER HALOS; SUPRIME-CAM; SHEAR; TELESCOPE; GALAXIES; CLUSTERS; SHAPELETS AB We assess the relative merits of weak-lensing surveys, using overlapping imaging data from the ground-based Subaru telescope and the Hubble Space Telescope (HST). Our tests complement similar studies undertaken with simulated data. From observations of 230,000 matched objects in the 2 deg(2) COSMOS field, we identify the limit at which faint galaxy shapes can be reliably measured from the ground using well-established shape-measurement techniques. Our ground-based shear catalog achieves subpercent calibration bias compared to high-resolution space-based data for galaxies brighter than i' similar or equal to 24.5 and with half-light radii larger than 1.8 ''. This selection corresponds to a surface density of 15 galaxies arcmin(-2) compared to similar to 71 arcmin(-2) from space. On the other hand, the survey speed of current ground-based facilities is much faster than that of HST, although this gain is mitigated by the increased depth of space-based imaging desirable for tomographic (3D) analyses. As an independent experiment, we also reconstruct the projected mass distribution in the COSMOS field using both data sets, and compare the derived cluster catalogs with those from X-ray observations. The ground-based catalog achieves a reasonable degree of completeness, with minimal contamination and no detected bias, formassive clusters at redshifts 0.2 < z < 0.5. The space-based data provide improved precision and a greater sensitivity to clusters of lower mass or at higher redshift. C1 [Kasliwal, Mansi M.; Massey, Richard; Ellis, Richard S.; Rhodes, Jason] CALTECH, Pasadena, CA 91125 USA. [Miyazaki, Satoshi] Natl Astron Observ Japan, Tokyo 1818588, Japan. [Rhodes, Jason] CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RP Kasliwal, MM (reprint author), CALTECH, MS 105-24, Pasadena, CA 91125 USA. FU US Department of Energy [DE-FG02-04ER41316]; NASA [NAS 5-26555] FX This work is supported by the US Department of Energy under contract DE-FG02-04ER41316. J. R.'s contribution was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration and funded through the internal Research and Technology Development program. The analysis is based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. It is also based on data collected at the Subaru Telescope, operated by the National Astronomical Observatory of Japan. We acknowledge the careful comments of a referee and also valuable input from Zeljko Ivezik, Alexandre Refregier, James Taylor, and Alexis Finoguenov. We particularly thank Alexie Leauthaud and Takashi Hamana for help with the two galaxy catalogs. We also gratefully acknowledge the contributions of the entire COSMOS collaboration, consisting of more than 70 scientists worldwide. More information on the COSMOS survey is available from http://www.astro.caltech.edu/similar to cosmos. NR 67 TC 11 Z9 11 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 SEP 1 PY 2008 VL 684 IS 1 BP 34 EP 45 DI 10.1086/588517 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 341QV UT WOS:000258730700003 ER PT J AU Bolton, AS Treu, T Koopmans, LVE Gavazzi, R Moustakas, LA Burles, S Schlegel, DJ Wayth, R AF Bolton, Adam S. Treu, Tommaso Koopmans, Leon V. E. Gavazzi, Raphael Moustakas, Leonidas A. Burles, Scott Schlegel, David J. Wayth, Randall TI The Sloan Lens ACS Survey. VII. Elliptical galaxy scaling laws from direct observational mass measurements SO ASTROPHYSICAL JOURNAL LA English DT Review DE galaxies : elliptical and lenticular, cD; gravitational lensing; surveys ID DIGITAL SKY SURVEY; TO-LIGHT RATIO; SIGHT VELOCITY DISTRIBUTIONS; INFRARED FUNDAMENTAL PLANE; ABSORPTION-LINE SPECTRA; 3RD DATA RELEASE; GRAVITATIONAL LENS; DARK-MATTER; EINSTEIN RING; KECK SPECTROSCOPY AB We use a sample of 53 massive early-type strong gravitational lens galaxies with well-measured redshifts (ranging from z = 0.06 to 0.36) and stellar velocity dispersions (between 175 and 400 km s(-1)) from the Sloan Lens ACS (SLACS) Survey to derive numerous empirical scaling relations. The ratio between central stellar velocity dispersion and isothermal lens-model velocity dispersion is nearly unity within errors. The SLACS lenses define a fundamental plane (FP) that is consistent with the FP of the general population of early-type galaxies. We measure the relationship between strong-lensing mass M-lens within one-half effective radius (R-e/2) and the dimensional mass variable M-dim equivalent to G(-1) sigma(2)(e2)(R-e/2) to be log (M-lens/10(11) M-circle dot) = (1.03 +/- 0.04) log (M-dim/10(11) M-circle dot)+ (0.54 +/- 0.02) (where sigma(e2) is the projected stellar velocity dispersion within R-e/2). The near-unity slope indicates that the mass-dynamical structure of massive elliptical galaxies is independent of mass and that the "tilt'' of the SLACS FP is due entirely to variation in total (luminous plus dark) mass- to-light ratio with mass. Our results imply that dynamical masses serve as a good proxies for true masses in massive elliptical galaxies. Regarding the SLACS lenses as a homologous population, we find that the average enclosed two-dimensional (2D) mass profile goes as log[M(< R)/M-dim]=(1.10 +/- 0.09)log(R/ R-e)+(0.85 +/- 0.03), consistent with an isothermal (flat rotation curve) model when deprojected into three dimensions (3D). This measurement is inconsistent with the slope of the average projected aperture luminosity profile at a confidence level greater than 99.9%, implying a minimum dark matter fraction of f(DM) = 0.38 +/- 0.07 within 1 effective radius. We also present an analysis of the angular mass structure of the lens galaxies, which further supports the need for dark matter inside one effective radius. C1 [Bolton, Adam S.] Univ Hawaii, Inst Astron, Honolulu, HI 96822 USA. [Bolton, Adam S.] Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. [Treu, Tommaso; Gavazzi, Raphael] Univ Calif Santa Barbara, Dept Phys, Santa Barbara, CA 93101 USA. [Koopmans, Leon V. E.] Univ Groningen, Kapteyn Astron Inst, NL-9700 AV Groningen, Netherlands. [Gavazzi, Raphael] CNRS, Inst Astrophy Paris, UMR7095, F-75014 Paris, France. [Gavazzi, Raphael] Univ Paris 06, F-75014 Paris, France. [Moustakas, Leonidas A.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Burles, Scott] MIT, Dept Phys, Cambridge, MA 02139 USA. [Burles, Scott] MIT, Kavli Inst Astrophys & Space Res, Cambridge, MA 02139 USA. [Schlegel, David J.] Lawrence Berkeley Natl Lab, Div Phys, Berkeley, CA 94720 USA. RP Bolton, AS (reprint author), Univ Hawaii, Inst Astron, 2680 Woodlawn Dr, Honolulu, HI 96822 USA. EM bolton@ifa.hawaii.edu; tt@physics.ucsb.edu; koopmans@astro.rug.nl; gavazzi@iap.fr; leonidas@jpl.nasa.gov; burles@mit.edu; djschlegel@lbl.gov; rwayth@cfa.harvard.edu RI Wayth, Randall/B-2444-2013 OI Wayth, Randall/0000-0002-6995-4131 FU National Science Foundation (NSF) [NSF 0642621]; Sloan Foundation [639.042.505]; European Community's Sixth Framework Marie Curie Research Training Network Programme [MRTN-CT-2004-505183]; National Aeronautics and Space Administration (NASA); NASA [10174, 10494, 10587, 10798, 10886]; Space Telescope Science Institute; Association of Universities for Research in Astronomy (AURA), Inc. [NAS5-26555]; Alfred P. Sloan Foundation; NSF; Department of Energy; Japanese Monbukagakusho; Max Planck Society; Higher Education Funding Council for England FX A. S. B., T. T., L. V. E. K., R. G., and L. A. M. acknowledge the support and hospitality of the Kavli Institute for Theoretical Physics at the University of California, Santa Barbara, where the early stages of this work were completed. A. S. B. thanks G. Dobler, G. Novak, and S. Faber for valuable discussion related to this work. T. T. acknowledges support from the National Science Foundation (NSF) through CAREER award NSF 0642621 and from the Sloan Foundation through a Sloan Research Fellowship. He is also supported by a Packard fellowship. L. V. E. K. is supported in part through an NWO-VIDI program subsidy (project number 639.042.505). He also acknowledges the continuing support by the European Community's Sixth Framework Marie Curie Research Training Network Programme, contract MRTN-CT-2004-505183 (ANGLES). The work of L. A. M. was carried out at Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration (NASA). Support for HST programs 10174, 10494, 10587, 10798, and 10886 was provided by NASA through a grant from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy (AURA), Inc., under NASA contract NAS5-26555. Please see HST data acknowledgment on the title page. This work has made extensive use of the Sloan Digital Sky Survey database. Funding for the SDSS and SDSS-II has been provided by the Alfred P. Sloan Foundation, the Participating Institutions, the NSF, the Department of Energy, NASA, the Japanese Monbukagakusho, the Max Planck Society, and the Higher Education Funding Council for England. The SDSSWeb Site is http://www.sdss.org. The SDSS is managed by the Astrophysical Research Consortium for the Participating Institutions. NR 137 TC 123 Z9 124 U1 0 U2 5 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 SEP 1 PY 2008 VL 684 IS 1 BP 248 EP 259 DI 10.1086/589989 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 341QV UT WOS:000258730700018 ER PT J AU Swartz, DA Soria, R Tennant, AF AF Swartz, Douglas A. Soria, Roberto Tennant, Allyn F. TI Do ultraluminous X-ray sources exist in dwarf galaxies? SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : general; X-rays : galaxies; X-rays : general ID STAR-FORMATION; NEARBY GALAXIES; STATISTICAL PROPERTIES; IRREGULAR GALAXIES; MASS; POPULATIONS; CLUSTERS AB A thorough search for ultraluminous X-ray source candidates within the Local Volume is made. The search spatially matches potential ULXs detected in X-ray images or cataloged in the literature with galaxies tabulated in the Catalog of Neighboring Galaxies compiled by Karachentsev et al. The specific ULX frequency (occurrence rate per unit galaxy mass) is found to be a decreasing function of host galaxy mass for host masses above similar to 10(8.5) M(circle dot). There is too little mass in galaxies below this point to determine whether this trend continues to lower galaxy mass. No ULXs have yet been detected in lower mass galaxies. Systematic differences between dwarf and giant galaxies that may explain an abundance of ULXs in dwarf galaxies and what they may imply about the nature of ULXs are discussed. C1 [Swartz, Douglas A.] NASA, George C Marshall Space Flight Ctr, Univ Space Res Assoc, Huntsville, AL 35812 USA. [Soria, Roberto] UCL, Mullard Space Sci Lab, Holmbury RH5 6NT, Surrey, England. [Tennant, Allyn F.] NASA, George C Marshall Space Flight Ctr, Dept Space Sci, Huntsville, AL 35812 USA. RP Swartz, DA (reprint author), NASA, George C Marshall Space Flight Ctr, Univ Space Res Assoc, VP62, Huntsville, AL 35812 USA. FU Chandra X-Ray Observatory Center [GO6-7081A]; NASA [NAS8-03060] FX This work was supported, in part, by Chandra Award GO6-7081A issued by the Chandra X-Ray Observatory Center which is operated by the Smithsonian Astrophysical Observatory for and on behalf of NASA under contract NAS8-03060. NR 32 TC 30 Z9 30 U1 0 U2 1 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 SEP 1 PY 2008 VL 684 IS 1 BP 282 EP 286 DI 10.1086/587776 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 341QV UT WOS:000258730700021 ER PT J AU Ross, T Baker, EJ Snow, TP Destree, JD Rachford, BL Drosback, MM Jensen, AG AF Ross, Teresa Baker, Emily J. Snow, Theodore P. Destree, Joshua D. Rachford, Brian L. Drosback, Meredith M. Jensen, Adam G. TI The search for H- in astrophysical environments SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : abundances; ISM : atoms; ISM : lines and bands; planetary nebulae : general ID ENERGY ELECTRON SCATTERING; ATOMIC HYDROGEN; NEGATIVE-IONS; RESONANCES; PHOTODETACHMENT; ABSORPTION; MOLECULES; STARS; EXCITATION; FESHBACH AB The negative ion H- is widely understood to be important in many astrophysical environments, including the atmospheres of late-type stars like the Sun. However, the ion has never been detected spectroscopically outside the laboratory. A search for the far-ultraviolet autodetaching transitions of H- in interstellar and circumstellar matter seems to be the best hope for directly detecting this ion. We undertook a highly sensitive search using data from the FUSE instrument. We concentrated on two types of sight lines: planetary nebulae, where model calculations suggest a sufficient abundance of H- to be determined, and translucent clouds, where H- might form on dust grains as an intermediate step in molecular hydrogen formation. Upper limits on H- abundances were set. C1 [Ross, Teresa; Baker, Emily J.; Snow, Theodore P.; Destree, Joshua D.; Drosback, Meredith M.] Univ Colorado, Ctr Astrophys & Space Astron, Dept Astrophys & Planetary Sci, Boulder, CO 80309 USA. [Rachford, Brian L.] Embry Riddle Aeronaut Univ, Dept Phys, Prescott, AZ 86301 USA. [Jensen, Adam G.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Ross, T (reprint author), Univ Colorado, Ctr Astrophys & Space Astron, Dept Astrophys & Planetary Sci, Campus Box 389, Boulder, CO 80309 USA. EM teresa.ross@colorado.edu; emily.j.baker@colorado.edu; tsnow@casa.colorado.edu; destree@casa.colorado.edu; rachf7ac@erau.edu; meredith.drosback@colorado.edu; adam.g.jensen@nasa.gov FU NASA [NAS5-32985] FX This work was funded through NASA contract NAS5-32985. The research made use of the MAST FUSE archive. We would like to thank the referee for his comments; they have greatly improved the quality of the manuscript. NR 37 TC 19 Z9 19 U1 0 U2 6 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 SEP 1 PY 2008 VL 684 IS 1 BP 358 EP 363 DI 10.1086/590242 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 341QV UT WOS:000258730700025 ER PT J AU Milam, SN Halfen, DT Tenenbaum, ED Apponi, AJ Woolf, NJ Ziurys, LM AF Milam, S. N. Halfen, D. T. Tenenbaum, E. D. Apponi, A. J. Woolf, N. J. Ziurys, L. M. TI Constraining phosphorus chemistry in carbon- and oxygen-rich circumstellar envelopes: Observations of PN, HCP, and CP SO ASTROPHYSICAL JOURNAL LA English DT Article DE astrobiology; astrochemistry; line : identification; stars : abundances; stars : chemically peculiar; stars : individual (CRL 2688; IRC+10216; VYCMa) ID VY-CANIS-MAJORIS; INTERSTELLAR-MEDIUM; MOLECULAR ABUNDANCES; PHOSPHAETHYNE HCP; IRC+10216; STARS; CRL-2688; IRC; SUBMILLIMETER; SPECTROSCOPY AB Millimeter-wave observations of PN, CP, and HCP have been carried out toward circumstellar envelopes of evolved stars using the Arizona Radio Observatory (ARO). HCP and PN have been identified in the carbon-rich source CRL 2688 via observations at 1 mm using the Submillimeter Telescope (SMT) and 2-3 mm with the Kitt Peak 12 m. An identical set of measurements were carried out toward IRC + 10216, as well as observations of CP at 1 mm. PN was also observed toward VY Canis Majoris (VY CMa), an oxygen-rich supergiant star. The PN and HCP line profiles in CRL 2688 and IRC + 10216 are roughly flat topped, indicating unresolved, optically thin emission; CP, in contrast, has a distinct "U" shape in IRC + 10216. Modeling of the line profiles suggests abundances, relative to H(2), of f (PN) similar to (3-5) x 10(-9) and f (HCP) similar to 2 x 10(-7) in CRL 2688, about an order of magnitude higher than in IRC + 10216. In VY CMa, f(PN) is similar to 4 x 10(-8). The data in CRL 2688 and IRC + 10216 are consistent with LTE formation of HCP and PN in the inner envelope, as predicted by theoretical calculations, with CP a photodissociation product at larger radii. The observed abundance of PN in VY CMa is a factor of 100 higher than LTE predictions. In IRC + 10216, the chemistry of HCP/CP mimics that of HCN/CN and suggests an N(2) abundance of f similar to 1 x 10(-7). The chemistry of phosphorus appears active in both carbon-and oxygen-rich envelopes of evolved stars. C1 [Milam, S. N.] NASA, Ames Res Ctr, SETI Inst, Moffett Field, CA 94035 USA. [Halfen, D. T.; Tenenbaum, E. D.; Woolf, N. J.; Ziurys, L. M.] Univ Arizona, Dept Astron, Dept Chem, NASA,Astrobiol Inst,Steward Observ, Tucson, AZ 85721 USA. RP Milam, SN (reprint author), NASA, Ames Res Ctr, SETI Inst, MS 245-6, Moffett Field, CA 94035 USA. EM stefanie.n.milam@nasa.gov; halfendt@as.arizona.edu; emilyt@as.arizona.edu; aapponi@gmail.com; nwoolf@as.arizona.edu; lziurys@as.arizona.edu RI Milam, Stefanie/D-1092-2012; OI Milam, Stefanie/0000-0001-7694-4129; Halfen, DeWayne/0000-0003-2483-3616 FU NSF [AST 0607803]; National Aeronautics and Space Administration; Cooperative Agreement [CAN-02-OSS-02]; NSF Astronomy and Astrophysics Postdoctoral Fellowship [AST-0602282]; NSF Graduate Research Fellowship Program FX We would like to thank the ARO operators and engineering staff. In addition, we would like to acknowledge J.H. Bieging and M. Tafalla for use of their radiative transfer code. This research was supported by NSF grant AST 0607803 and based on work supported by the National Aeronautics and Space Administration through the NASA Astrobiology Institute under Cooperative Agreement CAN-02-OSS-02 issued through the Office of Space Science. D. T. H. is supported by an NSF Astronomy and Astrophysics Postdoctoral Fellowship under award AST-0602282. E. D. T. acknowledges financial support from the NSF Graduate Research Fellowship Program. NR 46 TC 36 Z9 36 U1 0 U2 9 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 SEP 1 PY 2008 VL 684 IS 1 BP 618 EP 625 DI 10.1086/589135 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 341QV UT WOS:000258730700045 ER PT J AU Jacoutot, L Kosovichev, AG Wray, A Mansour, NN AF Jacoutot, L. Kosovichev, A. G. Wray, A. Mansour, N. N. TI Realistic numerical simulations of solar convection and oscillations in magnetic regions SO ASTROPHYSICAL JOURNAL LETTERS LA English DT Article DE convection; methods : numerical; Sun : oscillations ID RADIAL OSCILLATIONS; MODES; EXCITATION; FIELDS AB We have used 3D, compressible, nonlinear radiative magnetohydrodynamics simulation to study the influence of magnetic fields of various strengths on convective cells and on the excitation mechanisms of acoustic oscillations by calculating the spectral properties of the convective motions and oscillations. The results reveal substantial changes of the granulation structure with increased magnetic field and a frequency-dependent reduction in the oscillation power in a good agreement with solar observations. These simulations suggest that the enhanced high-frequency acoustic emission at the boundaries of active regions ("acoustic halo" phenomenon) is caused by changes of the spatial-temporal spectrum of turbulent convection in a magnetic field, resulting in turbulent motions of smaller scales and higher frequencies than in quiet-Sun regions. C1 [Jacoutot, L.] Stanford Univ, Ctr Turbulence Res, Stanford, CA 94305 USA. [Kosovichev, A. G.] Stanford Univ, Hansen Expt Phys Lab, Stanford, CA 94305 USA. [Wray, A.; Mansour, N. N.] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Jacoutot, L (reprint author), Stanford Univ, Ctr Turbulence Res, Stanford, CA 94305 USA. NR 18 TC 45 Z9 45 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA J9 ASTROPHYS J LETT JI Astrophys. J. Lett. PD SEP 1 PY 2008 VL 684 IS 1 BP L51 EP L54 DI 10.1086/592042 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 340BU UT WOS:000258621900013 ER PT J AU Plavchan, P Gee, AH Stapelfeldt, K Becker, A AF Plavchan, Peter Gee, Alan H. Stapelfeldt, Karl Becker, Andrew TI The peculiar periodic YSO WL 4 in rho Ophiuchus SO ASTROPHYSICAL JOURNAL LETTERS LA English DT Article DE circumstellar matter; stars : pre-main-sequence; stars : variables : other ID MAIN-SEQUENCE TRACKS; KH 15D; CLOUD CORE; INFRARED OBSERVATIONS; MYSTERIOUS ECLIPSES; MOLECULAR CLOUD; IMAGING SURVEY; MASS STARS; BINARY; VARIABILITY AB We present the discovery of 130.87 day periodic near-infrared flux variability for the Class II T Tauri star WL 4 (=2MASS J16271848-2429059, ISO-Oph 128). Our data are from the 2MASS Calibration Point Source Working Database and constitute 1580 observations in J, H, and K(s) of a field in rho Ophiuchus used to calibrate the 2MASS All- Sky Survey. We identify a light curve for WL 4 with eclipse amplitudes of similar to 0.4 mag lasting more than one-quarter the period and color variations in J-H and H-K(s) of similar to 0.1 mag. The long period cannot K s be explained by stellar rotation. We propose that WL 4 is a triple YSO system, with an inner binary orbital period of 130.87 days. We posulate that we are observing each component of the inner binary alternately being eclipsed by a circumbinary disk with respect to our line of sight. This system will be useful in investigating terrestrial-zone YSO disk properties and dynamics at similar to 1 Myr. C1 [Plavchan, Peter; Gee, Alan H.] CALTECH, Ctr Infrared Proc & Anal, Pasadena, CA 91125 USA. [Plavchan, Peter; Stapelfeldt, Karl] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Becker, Andrew] Univ Washington, Dept Astron, Seattle, WA 98195 USA. RP Plavchan, P (reprint author), CALTECH, Ctr Infrared Proc & Anal, M-C 100-22,S Wilson Ave, Pasadena, CA 91125 USA. RI Stapelfeldt, Karl/D-2721-2012 FU NASA; NSF FX This publication makes extensive use of data products from 2MASS, which is a joint project of the University of Massachusetts and IPAC/California Institute of Technology, funded by NASA and NSF. This research has made use of the NASA/IPAC Infrared Science Archive, which is operated by Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA. Thanks to Mike Meyer, Mike Werner, Angelle Tanner, and Eric Agol for their conversations and comments. Parts of the research described in this publication were carried out at JPL. NR 43 TC 28 Z9 28 U1 0 U2 0 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 SEP 1 PY 2008 VL 684 IS 1 BP L37 EP L40 DI 10.1086/592107 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 340BU UT WOS:000258621900010 ER PT J AU Le Marshall, J Jung, J Goldberg, M Barnet, C Wolf, W Derber, J Treadon, R Lord, S AF Le Marshall, J. Jung, J. Goldberg, M. Barnet, C. Wolf, W. Derber, J. Treadon, R. Lord, S. TI Using cloudy AIRS fields of view in numerical weather prediction SO AUSTRALIAN METEOROLOGICAL MAGAZINE LA English DT Article ID RADIANCES C1 [Le Marshall, J.] Australian Bur Meteorol, Ctr Australian Weather & Climate Res, Melbourne, Vic 3001, Australia. [Le Marshall, J.] CSIRO, Clayton, Vic, Australia. [Le Marshall, J.; Jung, J.] NASA, NOAA, Washington, DC USA. [Jung, J.] Univ Wisconsin, CIMSS, Madison, WI 53706 USA. [Goldberg, M.; Barnet, C.; Wolf, W.] NOAA, NESDIS Ctr Satellite Applicat & Res, Washington, DC USA. [Derber, J.; Treadon, R.; Lord, S.] NOAA, NWS, NCEP, Washington, DC USA. RP Le Marshall, J (reprint author), Australian Bur Meteorol, Ctr Australian Weather & Climate Res, GPO Box 1289, Melbourne, Vic 3001, Australia. EM j.lemarshall@bom.gov.au RI Barnet, Christopher/F-5573-2010; Goldberg, Mitch/F-5589-2010; Wolf, Walter/E-7935-2011 OI Wolf, Walter/0000-0002-2102-8833 NR 11 TC 6 Z9 6 U1 0 U2 0 PU AUSTRALIAN BUREAU METEOROLOGY PI MELBOURNE PA GPO BOX 1289, MELBOURNE, VIC 3001, AUSTRALIA SN 0004-9743 J9 AUST METEOROL MAG JI Aust. Meteorol. Mag. PD SEP PY 2008 VL 57 IS 3 BP 249 EP 254 PG 6 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 405SL UT WOS:000263244400005 ER PT J AU Crucian, BE Stowe, RP Pierson, DL Sams, CF AF Crucian, Brian E. Stowe, Raymond P. Pierson, Duane L. Sams, Clarence F. TI Immune system dysregulation following short- vs long-duration spaceflight SO AVIATION SPACE AND ENVIRONMENTAL MEDICINE LA English DT Article DE immune function; microgravity; cytokines ID EPSTEIN-BARR-VIRUS; SPACE-FLIGHT; SIGNAL-TRANSDUCTION; CYTOKINE PRODUCTION; T-LYMPHOCYTES; ASTRONAUTS; MICROGRAVITY; REACTIVATION; EXPRESSION; COSMONAUTS AB Introduction: Immune system dysregulation has been demonstrated to occur during and immediately following spaceflight. If found to persist during lengthy flights, this phenomenon could be a serious health risk to crewmembers participating in lunar or Mars missions. Methods: A comprehensive postflight immune assessment was performed on 17 short-duration Space Shuttle crewmembers and 8 long-duration International Space Station (ISS) crewmembers. Testing consisted of peripheral leukocyte subset analysis, early T cell activation potential, and intracellular/secreted cytokine profiles. Results: For Shuttle crewmembers, the distribution of the peripheral leukocyte subsets was found to be altered postflight. Early T cell activation was elevated postflight; however, the percentage of T cell subsets capable of being stimulated to produce IL-2 and IFN gamma was decreased. The ratio of secreted IFN gamma:IL-10 following T cell stimulation declined after landing, indicating a Th2 shift. For the ISS crewmembers, some alterations in peripheral leukocyte distribution were also detected after landing. In contrast to Shuttle crewmembers, the ISS crewmembers demonstrated a statistically significant reduction in early T cell activation potential immediately postflight. The percentage of T cells capable of producing IL-2 was reduced, but IFN gamma percentages were unchanged. A reduction in the secreted IFNy:IL-10 ratio (Th2 shift) was also observed postflight in the ISS crewmembers. Conclusion: These data indicate that consistent peripheral phenotype changes and altered cytokine production profiles occur following spaceflight of both short and long duration; however, functional immune dysregulation may vary related to mission duration. In addition, a detectable Th2 cytokine shift appears to be associated with spaceflight. C1 [Crucian, Brian E.] Human Adaptat & Countermeasures Off, Wyle Labs, Houston, TX 77059 USA. [Sams, Clarence F.] NASA, Lyndon B Johnson Space Ctr, Immunol Lab, Houston, TX 77058 USA. [Stowe, Raymond P.] Microgen Labs, Lamarque, TX USA. [Pierson, Duane L.] NASA, Lyndon B Johnson Space Ctr, Microbiol Lab, Houston, TX 77058 USA. RP Crucian, BE (reprint author), Human Adaptat & Countermeasures Off, Wyle Labs, 1290 Hercules Dr, Houston, TX 77059 USA. EM brian.crucian-1@nasa.gov NR 30 TC 67 Z9 83 U1 0 U2 9 PU AEROSPACE MEDICAL ASSOC PI ALEXANDRIA PA 320 S HENRY ST, ALEXANDRIA, VA 22314-3579 USA SN 0095-6562 J9 AVIAT SPACE ENVIR MD JI Aviat. Space Environ. Med. PD SEP PY 2008 VL 79 IS 9 BP 835 EP 843 DI 10.3357/ASEM.2276.2008 PG 9 WC Public, Environmental & Occupational Health; Medicine, General & Internal; Sport Sciences SC Public, Environmental & Occupational Health; General & Internal Medicine; Sport Sciences GA 344UG UT WOS:000258952200001 PM 18785351 ER PT J AU Kleinhenz, J Feier, II Hsu, SY T'ien, JS Ferkul, PV Sacksteder, KR AF Kleinhenz, Julie Feier, Ioan I. Hsu, Sheng-Yen T'ien, James S. Ferkul, Paul V. Sacksteder, Kurt R. TI Pressure modeling of upward flame spread and burning rates over solids in partial gravity SO COMBUSTION AND FLAME LA English DT Article DE upward flame spread; partial gravity; pressure modeling; solid burning ID RADIATION; FLOW AB Pressure-gravity modeling is proposed as a means to simulate upward flame spread and burning rates over, vertical solid samples in partial gravity environments, Such its oil the Moon and oil Mars. Based oil experimental results ill reduced gravity, the upward flame spread rate data over thin solids can be correlated by the expression p(1.8)g (where p is the ambient pressure and g is the gravity level). This is close to the theoretical p(2)g factor in preserving the Grashof number and is also supported by detailed numerical simulations. Since the flame size, shape and standoff distance are preserved in this simulation, it is expected that combustion properties, controlled chiefly by convective heat transfer are properly accounted for by the present technique. This includes upward flame spread rates, growth rates, and burning rates over thin and thick solids in both laminar and turbulent flames. In flames where the heat transfer is dominated by soot emission, more studies are needed to verify the validity of this correlation. (C) 2008 The Combustion Institute. Published by Elsevier Inc. All rights reserved. C1 [Kleinhenz, Julie; Feier, Ioan I.; Hsu, Sheng-Yen; T'ien, James S.] Case Western Reserve Univ, Cleveland, OH 44106 USA. [Ferkul, Paul V.] Natl Ctr Space Explorat Res, Cleveland, OH 44135 USA. [Sacksteder, Kurt R.] NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP T'ien, JS (reprint author), Case Western Reserve Univ, Cleveland, OH 44106 USA. EM jst2@case.edu FU NASA [NNC04AA58A, NNC04AA33A] FX We would like to thank Drs. Amit Kumar and Gary Ruff for their advice and encouragement. J.S.T. Would also like to acknowledge in earlier conversation with Dr. Carl Engel which triggered this work. This research is Supported through NASA grants NNC04AA58A and NNC04AA33A. NR 18 TC 16 Z9 16 U1 0 U2 8 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 SEP PY 2008 VL 154 IS 4 BP 637 EP 643 DI 10.1016/j.combustflame.2008.05.023 PG 7 WC Thermodynamics; Energy & Fuels; Engineering, Multidisciplinary; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA 344PR UT WOS:000258940300001 ER PT J AU Sidebotham, GW Olson, SL AF Sidebotham, George W. Olson, Sandra L. TI Microgravity opposed-flow flame spread in polyvinyl chloride tubes SO COMBUSTION AND FLAME LA English DT Article DE flame spread; microgravity; buoyancy; polyvinyl chloride; oxygen; tubing ID SOLID-FUEL; FIRE AB The effects of gravity on opposed-flow flame spread in a confined geometry were investigated experimentally in the 2.2-s drop tower at the NASA Glenn Research Center. Pure oxygen flowed through samples of 0.64-cm-inner-diameter polyvinyl chloride (PVC) tubing held either horizontally or vertically in a combustion chamber filled with nitrogen. The sample was ignited in normal gravity with a hot wire, and once a flame was established, the apparatus was dropped was dropped to observe microgravity effects. Flame spread rate was measured in normal and microgravity at pressures of 1.0 and 0.5 atm. A low-flow ignition limit was observed at an opposed-flow velocity of 1.36 cm/s, at which point the horizontal, vertical, and microgravity flame spread rates were 0.40, 0.30, and 0.16 cm/s, respectively. For flow velocities above approximately 5.2 cm/s, there was no difference in the flame spread rates for normal and microgravity and the flame spread rate increased with a nearly square root dependence with respect to opposed-flow velocity. Buoyant flow velocities of 2.5 and 1.5 cm/s were estimated for horizontal and vertical flames, respectively. Vertical tests conducted at 0.5 atm pressure demonstrated no difference in flame spread rate between normal and microgravity. These results suggest that the fire risk associated with the use of PVC tubes during general anesthesia in either space or ground applications may be reduced if the application of a high-energy surgical tool is prevented during an active phase of the breathing cycle (inhale or exhale). (C) 2008 The Combustion Instititute. Published by Elsevier Inc. All rights reserved. C1 [Sidebotham, George W.] Cooper Union Adv Sci & Art, Dept Mech Engn, New York, NY 10003 USA. [Olson, Sandra L.] NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Sidebotham, GW (reprint author), Cooper Union Adv Sci & Art, Dept Mech Engn, 51 Astor Pl, New York, NY 10003 USA. EM sideho@cooper.edu FU NASA Faculty Fellowship Program FX This paper is dedicated to the late Gerald L, Wolf, M.D., who brought this problem to the attention of the combustion community and worked tirelessly to educate the medical community on this and other fire safety risks. This work was supported by the NASA Faculty Fellowship Program (summer 2003). The contributions of the technical staff of the NASA Glenn 2.2-s drop tower are greatly appreciated. Special thanks to Peter Sunderland for help with all technical aspects of the project. NR 20 TC 2 Z9 2 U1 0 U2 2 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 SEP PY 2008 VL 154 IS 4 BP 789 EP 801 DI 10.1016/j.combustflame.2008.05.01 PG 13 WC Thermodynamics; Energy & Fuels; Engineering, Multidisciplinary; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA 344PR UT WOS:000258940300011 ER PT J AU Makeev, MA Srivastava, D AF Makeev, Maxim A. Srivastava, Deepak TI Molecular dynamics simulations of hypersonic velocity impact protection properties of CNT/a-SiC composites SO COMPOSITES SCIENCE AND TECHNOLOGY LA English DT Article DE Impact behavior; Nano-reinforced composites; Damage tolerance ID MATRIX COMPOSITES; CARBON NANOTUBES; NANOCOMPOSITES AB The hypersonic velocity impact protection properties of carbon-nanotube-reinforced amorphous silicon carbide composites are investigated using molecular dynamics simulation. The projectile-impact-induced damage to target materials is analyzed for composite targets having perpendicular and parallel alignments of carbon nanotubes with respect to impact direction, and compared to that of pristine amorphous silicon carbide target. It was found that, in the considered range of impact velocities, the penetration depth is approximately the same for both CNT-reinforced composites and pristine a-SiC target. At short time-scales, damage to a target is defined by penetration depth of projectile and density rearrangements taking place in the target material. In the composite with carbon nanotubes aligned parallel to the impact direction, a channeling of damage to deeper regions of the target occurs. In the case of perpendicular alignment, the damage is confined to a narrow region underneath the penetrating projectile. For both considered composite samples, we found that a significant damping of the amplitudes of compressive shock-waves takes place, thus reducing the special extent of damage in composites as compared to that in the pristine a-SiC target. (C) 2008 Published by Elsevier Ltd. C1 [Makeev, Maxim A.; Srivastava, Deepak] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Makeev, MA (reprint author), NASA, Ames Res Ctr, Mail Stop 229-1, Moffett Field, CA 94035 USA. EM mmakeev@mail.arc.nasa.gov; dsrivastava@mail.arc.nasa.gov FU NASA [NAS2-03144] FX M.A M. and D.S. gratefully acknowledge support from NASA (Contract No. NAS2-03144 to UARC). NR 20 TC 5 Z9 5 U1 4 U2 16 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 SEP PY 2008 VL 68 IS 12 SI SI BP 2451 EP 2455 DI 10.1016/j.compscitech.2008.04.040 PG 5 WC Materials Science, Composites SC Materials Science GA 363QI UT WOS:000260281400020 ER PT J AU Brock, JC Palaseanu-Lovejoy, M Wright, CW Nayegandhi, A AF Brock, J. C. Palaseanu-Lovejoy, M. Wright, C. W. Nayegandhi, A. TI Patch-reef morphology as a proxy for Holocene sea-level variability, Northern Florida Keys, USA SO CORAL REEFS LA English DT Article DE lidar; Holocene; sea-level fluctuations; patch reefs; morphology; Florida Keys ID ACROPORA-PALMATA FRAMEWORK; INTERTIDAL MANGROVE PEAT; CALIBRATED C-14 DATES; BISCAYNE-NATIONAL-PARK; GULF-OF-MEXICO; CORAL-REEFS; LAST DEGLACIATION; ICE-SHEET; HISTORY; ATLANTIC AB A portion of the northern Florida Keys reef tract was mapped with the NASA Experimental Advanced Airborne Research Lidar (EAARL) and the morphology of patch reefs was related to variations in Holocene sea level. Following creation of a lidar digital elevation model (DEM), geospatial analyses delineated morphologic attributes of 1,034 patch reefs (reef depth, basal area, height, volume, and topographic complexity). Morphometric analysis revealed two morphologically different populations of patch reefs associated with two distinct depth intervals above and below a water depth of 7.7 m. Compared to shallow reefs, the deep reefs were smaller in area and volume and showed no trend in topographic complexity relative to water depth. Shallow reefs were more variable in area and volume and became flatter and less topographically complex with decreasing water depth. The knoll-like morphology of deep reefs was interpreted as consistent with steady and relatively rapidly rising early Holocene sea level that restricted the lateral growth of reefs. The morphology of shallow "pancake-shaped" reefs at the highest platform elevations was interpreted as consistent with fluctuating sea level during the late Holocene. Although the ultimate cause for the morphometric depth trends remains open to interpretation, these interpretations are compatible with a recent eustatic sea-level curve that hindcasts fluctuating late Holocene sea level. Thus it is suggested that the morphologic differences represent two stages of reef accretion that occurred during different sea-level conditions. C1 [Brock, J. C.; Palaseanu-Lovejoy, M.; Nayegandhi, A.] US Geol Survey, St Petersburg, FL 33701 USA. [Wright, C. W.] NASA, Goddard Space Flight Ctr, Wallops Flight Facil, Wallops Isl, VA 23337 USA. RP Brock, JC (reprint author), US Geol Survey, 600 4th St S, St Petersburg, FL 33701 USA. EM jbrock@usgs.gov NR 68 TC 10 Z9 10 U1 1 U2 17 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0722-4028 J9 CORAL REEFS JI Coral Reefs PD SEP PY 2008 VL 27 IS 3 BP 555 EP 568 DI 10.1007/s00338-008-0370-y PG 14 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA 332MA UT WOS:000258085900013 ER PT J AU Runyan, MC Jones, WC AF Runyan, M. C. Jones, W. C. TI Thermal conductivity of thermally-isolating polymeric and composite structural support materials between 0.3 and 4 K SO CRYOGENICS LA English DT Article DE thermal conductivity; polymers; composites; structural materials ID LOW-TEMPERATURES; GLASS; TORLON; HEAT; 2-K AB We present measurements of the low-temperature thermal conductivity of a number of polymeric and composite materials from 0.3 to 4 K. The materials measured are Vespel SP-1, Vespel SP-22, unfilled PEEK, 30% carbon fiber-filled PEEK, 30% glass-filled PEEK, carbon fiber Graphlite composite rod, Torlon 4301, G-10/FR-4 fiberglass, pultruded fiberglass composite, Macor ceramic, and graphite rod. These materials have moderate to high elastic moduli making them useful for thermally-isolating structural supports. (c) 2008 Elsevier Ltd. All rights reserved. C1 [Runyan, M. C.; Jones, W. C.] CALTECH, Dept Phys, Pasadena, CA 91125 USA. [Jones, W. C.] CALTECH, Jet Prop Lab, Observat Cosmol Grp, Pasadena, CA 91109 USA. RP Runyan, MC (reprint author), CALTECH, Dept Phys, MC59-33,1201 E Calif Blvd, Pasadena, CA 91125 USA. EM mcrorder@yahoo.com FU NASA [NNX07AL64G] FX This work was supported under the SPIDER project by NASA Grant No. NNX07AL64G. The authors wish to thank Justin Lazear for his assistance with thermometer cross-calibration, Mike Zemcov for pointing us to Poco Graphite, and Warren Holmes for useful discussions. NR 18 TC 19 Z9 19 U1 2 U2 12 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0011-2275 J9 CRYOGENICS JI Cryogenics PD SEP-OCT PY 2008 VL 48 IS 9-10 BP 448 EP 454 DI 10.1016/j.cryogenics.2008.06.002 PG 7 WC Thermodynamics; Physics, Applied SC Thermodynamics; Physics GA 351NF UT WOS:000259430300008 ER PT J AU Garcia, VMT Garcia, CAE Mata, MM Pollery, RC Piola, AR Signorini, SR McClain, CR Iglesias-Rodriguez, MD AF Garcia, Virginia M. T. Garcia, Carlos A. E. Mata, Mauricio M. Pollery, Ricardo C. Piola, Alberto R. Signorini, Sergio R. McClain, Charles R. Iglesias-Rodriguez, M. Debora TI Environmental factors controlling the phytoplankton blooms at the Patagonia shelf-break in spring SO DEEP-SEA RESEARCH PART I-OCEANOGRAPHIC RESEARCH PAPERS LA English DT Article DE phytoplankton bloom; nutrients; primary production; Patagonia shelf-break; Malvinas current ID SOUTH-ATLANTIC-OCEAN; SURFACE OCEAN; SOUTHWESTERN ATLANTIC; NORTH-ATLANTIC; CHLOROPHYLL-A; SEA; LIGHT; PHAEOCYSTIS; FRONTS; IRON AB The shelf-break front formed between Argentinean shelf waters and the Malvinas Current (MC) flow shows a conspicuous band of high phytoplankton biomass throughout spring and summer, detected by ocean color sensors. That area is the feeding and spawning ground of several commercial species of fish and squid and is thought to play an important role in CO2 sequestration by the ocean. Phytoplankton blooms in this area have been attributed mainly to coccolithophorids, a group of calcite-producing phytoplankton. Here we present the environmental factors associated with the spring bloom at the Patagonian shelf-break (40 degrees-48 degrees S) in the austral spring 2004. A remarkable bloom of diatoms and dinoflagellates (approximately 1200 km long) was observed along the front, where integrated chlorophyll values ranged from 90.3 to 1074 mg m(-2). It is suggested that supply of macro-nutrients by upwelling and probably iron by both upwelling and shelf transport contribute to maintaining the spring bloom. Strong water column stability along the front allowed the accumulation of algal cells mainly in the top 50m and their maintenance in the euphotic layer. East of the shelf-break front, macronutrient levels were high (surface nitrate = 16.6 mu M, phosphate = 0.35 mu M, silicate = 4.0 mu M), associated with low phytoplankton biomass (<2 mg m(-3)). This was due to mixing and advection associated with the MC flow and to grazing pressure at a transitional site between the MC and the high chlorophyll patch. Primary production rates (determined by the C-14 technique) ranged between 1.9 and 7.8 gCm(-2) d(-1). Primary production was highest near 42 degrees S partly because of the elevated phytoplankton biomass, which consumed most of the nitrate and phosphate in surface waters in this region. These high primary production rates are comparable with maximal seasonal productivity at eastern boundary currents. The large bloom extent at the Patagonian shelf-break (approximately 55,000 km(2) patch of > 2 mg m(-3) chlorophyll), the associated primary production rates and diatom dominance indicate a potentially significant biological control of gases such as O-2 and CO2 in surface layers. The main factors favoring the development and maintenance of these blooms are nutrient supply from MC upwelling and water column stability. Other processes such as mixing or grazing play an important role in biomass modulation in the region. (C) 2008 Elsevier Ltd. All rights reserved. C1 [Garcia, Virginia M. T.] Fed Univ Rio Grande, Dept Oceanog, BR-96201900 Rio Grande, RS, Brazil. [Garcia, Carlos A. E.; Mata, Mauricio M.] Fed Univ Rio Grande, Dept Phys, BR-96201900 Rio Grande, RS, Brazil. [Pollery, Ricardo C.] Univ Santa Ursula, Inst Biol & Environm Sci, BR-22231010 Rio De Janeiro, Brazil. [Piola, Alberto R.] Serv Hidog Naval, RA-1271 Buenos Aires, DF, Argentina. [Piola, Alberto R.] Univ Buenos Aires, RA-1053 Buenos Aires, DF, Argentina. [Signorini, Sergio R.; McClain, Charles R.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Iglesias-Rodriguez, M. Debora] Univ Southampton, Sch Ocean & Earth Sci, Natl Oceanog Ctr, Southampton SO14 3ZH, Hants, England. RP Garcia, VMT (reprint author), Fed Univ Rio Grande, Dept Oceanog, Av Italia,Km 8, BR-96201900 Rio Grande, RS, Brazil. EM birfurg@hotmail.com; dfsgar@furg.br; dfsmata@furg.br; pollery@hotmail.com; apiola@hidro.gov.ar; Sergio.Signorini@nasa.gov; charles.r.mcclain@nasa.gov; dir@noc.soton.ac.uk RI Tavano, Virginia/C-5241-2013; Piola, Alberto/O-2280-2013; Garcia, Carlos/K-7382-2012; Mata, Mauricio/H-4605-2011 OI Tavano, Virginia/0000-0003-0039-8111; Piola, Alberto/0000-0002-5003-8926; Mata, Mauricio/0000-0002-9028-8284 FU CNPq (Brazilian National Council on Research and Development); MMA (Ministry of Environment) [550370/02-1]; Inter-American Institute for Global Change Research [CRN2076]; US National Science Foundation [GEO-0452325] FX The Patagonian Experiment (PATEX) is a multidisciplinary project as part of GOAL (Group of High Latitude Oceanography) activities in the Brazilian Antarctic Program. We thank the crew of the Brazilian Navy research ship "Ary Rongel" for their assistance during the field sampling. The project was sponsored through the funding resources of CNPq (Brazilian National Council on Research and Development) and MMA (Ministry of Environment) to the Brazilian Antarctic Program (PROANTAR) through grant 550370/02-1. Ocean color images were provided by and processed at the GSFC (Goddard Space Flight Center). A.R.P. acknowledges the support of the Inter-American Institute for Global Change Research (Grant CRN2076), which is financed by the US National Science Foundation (Grant GEO-0452325). We are thankful for the constructive criticism of three anonymous reviewers, which greatly improved the manuscript. NR 61 TC 41 Z9 41 U1 0 U2 11 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0967-0637 J9 DEEP-SEA RES PT I JI Deep-Sea Res. Part I-Oceanogr. Res. Pap. PD SEP PY 2008 VL 55 IS 9 BP 1150 EP 1166 DI 10.1016/j.dsr.2008.04.011 PG 17 WC Oceanography SC Oceanography GA 347JO UT WOS:000259136700006 ER PT J AU Ross, RM Quetin, LB Martinson, DG Iannuzzi, RA Stammerjohn, SE Smith, RC AF Ross, Robin M. Quetin, Langdon B. Martinson, Douglas G. Iannuzzi, Rich A. Stammerjohn, Sharon E. Smith, Raymond C. TI Palmer LTER: Patterns of distribution of five dominant zooplankton species in the epipelagic zone west of the Antarctic Peninsula, 1993-2004 SO DEEP-SEA RESEARCH PART II-TOPICAL STUDIES IN OCEANOGRAPHY LA English DT Article DE Southern ocean; Sea-ice; Spatial variation; Time series analysis; Zooplankton ID KRILL EUPHAUSIA-SUPERBA; SEA-ICE EXTENT; SOUTHERN-OCEAN; MACROZOOPLANKTON COMMUNITY; CROKER-PASSAGE; CARBON FLUX; SCOTIA SEA; VARIABILITY; RECRUITMENT; ABUNDANCE AB Variability in the temporal-spatial distribution and abundance of zooplankton was documented each summer on the Palmer Long-Term Ecological Research (LTER) grid west of the Antarctic Peninsula between Anvers and Adelaide Islands during a 12-yr time series. Oblique tows to 120 m with a 2 x 2 m fixed-frame net were made at about 50 stations each January/February between 1993 and 2004. The numerically dominant macro- and mesozooplanktonic species >2mm included three species of euphausiids (Euphausia superba, Antarctic krill; Thysano ssa macrura; Euphausia crystallorophias, ice krill), a shelled pteropod (Limacina helicina), and a salp (Salpa thompsoni). Life cycles, life spans, and habitat varied among these species. Abundance data from each year were allocated to 100 km by 20 km (alongshore by on/offshore) grid cells centered on cardinal transect lines and stations within the Palmer LTER grid. The long-term mean or climatology and means for each year were used to calculate annual anomalies across the grid. Principal components analysis (PCA) was used to analyze for patterns and trends in the temporal-spatial variability of the five species. Questions included whether there are groups of species with similar patterns, and whether population cycles, species interactions or seasonal sea-ice parameters were correlated with detected patterns. Patterns in the climatology were distinct, and matched those of physical parameters. Common features included higher abundance in the north than in the south, independent of the cross-shelf gradients, and cross-shelf gradients with higher abundance either inshore (E. crystallorophias) or offshore (S. thompsoni). Anomalies revealed either cycles in the population, as episodic recruitment in Antarctic krill, or changes in anomaly pattern between the first and second half of the sampling period. The 1998 year, which coincided with a rapid change from a negative to a positive phase in the SOI, emerged as a year with either significant anomalies or that marked a change in anomaly patterns for different species. PCA analysis showed that the pattern of cumulative variance with increasing number of modes was distinctly different for shorter-lived versus longer-lived species; the first mode accounted for nearly 50% of the variance in the shorter-lived species and less than 25% in the longer-lived species. This suggested that the mechanisms driving variability in the temporal-spatial distribution of the shorter-lived, more oceanic species were less complex and more direct than those for the longer-lived euphausiids. Evidence from both the anomaly plots and the trend analysis suggested that salps have been more consistently present across the shelf from 1999 to present, and that the range of L. helicina has been expanding. With shorter life spans, these two species can respond more quickly to the increasing heat content on the shelf in this region. The cross-correlation analysis illustrated the negative correlation between salps and ice retreat and the number of ice days, and the positive correlation between the presence of ice krill and the day of ice retreat. These results suggest that for these species, several environmental controls on distribution and abundance were linked to seasonal sea-ice dynamics. (C) 2008 Elsevier Ltd. All rights reserved. C1 [Ross, Robin M.; Quetin, Langdon B.] Univ Calif Santa Barbara, Inst Marine Sci, Santa Barbara, CA 93106 USA. [Martinson, Douglas G.; Iannuzzi, Rich A.] Columbia Univ, Lamont Doherty Earth Observ, Palisades, NY 10964 USA. [Stammerjohn, Sharon E.] NASA, Goddard Inst Space Studies, New York, NY 10025 USA. [Smith, Raymond C.] Univ Calif Santa Barbara, Inst Computat Earth Syst Sci, Santa Barbara, CA 93106 USA. RP Ross, RM (reprint author), Univ Calif Santa Barbara, Inst Marine Sci, Santa Barbara, CA 93106 USA. EM robin@icess.ucsb.edu OI STAMMERJOHN, SHARON/0000-0002-1697-8244 FU National Science Foundation; Office of Polar Programs [OPP-9011927, OPP9632763, OPP-0217282]; The Regents of the University of California; University of California; Marine Science Institute, UCSB; Palmer LTER [312] FX We gratefully acknowledge two research associates from the 1990s, T. Newberger and J. Jones, and all the graduate students and volunteers who were critical for the collection of the data. Without the ship-handling skills of the captains, mates and crews of the MV Polar Duke and ARSV Laurence M. Gould, and the logistical and on-board help of Antarctic Support Associates and Raytheon Polar Services personnel, the samples would never have made it to the deck for the volunteers to identify and count. Our discussions with our colleagues with the LTER have been invaluable, from tutorials on PCA analysis to discussions of various results. The long-term data analysis has been enjoyable and rewarding primarily due to our colleagues. This material is based upon work supported by the National Science Foundation, Office of Polar Programs, under Award Nos. OPP-9011927 and OPP9632763, and OPP-0217282, The Regents of the University of California, the University of California at Santa Barbara, and the Marine Science Institute, UCSB. This is Palmer LTER contribution No. 312. NR 53 TC 52 Z9 54 U1 1 U2 19 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0967-0645 EI 1879-0100 J9 DEEP-SEA RES PT II JI Deep-Sea Res. Part II-Top. Stud. Oceanogr. PD SEP PY 2008 VL 55 IS 18-19 BP 2086 EP 2105 DI 10.1016/j.dsr2.2008.04.037 PG 20 WC Oceanography SC Oceanography GA 373SK UT WOS:000260992700010 ER PT J AU Williams, ID Walsh, WJ Schroeder, RE Friedlander, AM Richards, BL Stamoulis, KA AF Williams, I. D. Walsh, W. J. Schroeder, R. E. Friedlander, A. M. Richards, B. L. Stamoulis, K. A. TI Assessing the importance of fishing impacts on Hawaiian coral reef fish assemblages along regional-scale human population gradients SO ENVIRONMENTAL CONSERVATION LA English DT Article DE coral reef; fishing; habitat; Hawaii; introduced species; natural refugia ID MARINE PROTECTED AREAS; BIOMASS; DEGRADATION; COMMUNITIES; FISHERIES; HABITAT; BIODIVERSITY; MOVEMENTS; RESERVES; DESIGN AB Humans can impact coral reef fishes directly by fishing, or indirectly through anthropogenic degradation of habitat. Uncertainty about the relative importance of those can make it difficult to develop and build consensus for appropriate remedial management. Relationships between fish assemblages and human population density were assessed using data from 18 locations widely spread throughout the Main Hawaiian Islands (MHI) to evaluate the significance of fishing as a factor potentially driving fish trends on a regional scale. Fish biomass in several groups was negatively correlated with local human population density and a number of lines of evidence indicate that fishing was the prime driver of those trends. First, declines were consistently evident among fish groups targeted by fishers, but not among lightly fished or non-target groupings, which indicates that declines in target groups were not simply indicative of a general decline in habitat quality along human population gradients. Second, proximity to high human populations was not associated with low fish biomass where shoreline structure prevented ready access by fishers. Relatively remote and inaccessible locations within the MHI had 2.1-4.2 times the biomass of target fishes compared to accessible and populous locations, and may therefore function as partial refugia. However, stocks in those areas were clearly far from pristine, as biomass of large predators was more than an order of magnitude lower than at more intact ecosystems elsewhere in the Pacific. C1 [Williams, I. D.] Univ Hawaii Manoa, Dept Zool, Hawaii Cooperat Fishery Res Unit, Honolulu, HI 96822 USA. [Williams, I. D.; Walsh, W. J.; Stamoulis, K. A.] Hawaii Div Aquat Resources, Kailua, HI 96740 USA. [Schroeder, R. E.; Richards, B. L.] Univ Hawaii, Joint Inst Marine & Atmospher Res, Honolulu, HI 96822 USA. [Schroeder, R. E.; Richards, B. L.] NOAA, Natl Marine Fisheries Serv, CRED, Pacific Isl Fisheries Sci Ctr, Honolulu, HI 96822 USA. [Friedlander, A. M.] NOAA, NOS NCCOS CCMA, Biogeog Branch, Waimanalo, HI 96795 USA. [Friedlander, A. M.] NOAA, NOS NCCOS CCMA, Ocean Inst, Waimanalo, HI 96795 USA. RP Williams, ID (reprint author), Univ Hawaii Manoa, Dept Zool, Hawaii Cooperat Fishery Res Unit, Honolulu, HI 96822 USA. EM ivor@hawaii.edu NR 43 TC 40 Z9 40 U1 2 U2 34 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 32 AVENUE OF THE AMERICAS, NEW YORK, NY 10013-2473 USA SN 0376-8929 J9 ENVIRON CONSERV JI Environ. Conserv. PD SEP PY 2008 VL 35 IS 3 BP 261 EP 272 DI 10.1017/S0376892908004876 PG 12 WC Biodiversity Conservation; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 377AQ UT WOS:000261224500009 ER PT J AU Ashtekar, K Kim, E Roy, AS Effat, M Helmy, T Schneeberger, E Gottliebson, W Back, L Banerjee, R AF Ashtekar, K. Kim, E. Roy, A. Sinha Effat, M. Helmy, T. Schneeberger, E. Gottliebson, W. Back, L. Banerjee, R. TI Delineation of true diagnostic severity of epicardial coronary stenosis and microvascular dysfunction using alternate diagnostic indices SO EUROPEAN HEART JOURNAL LA English DT Meeting Abstract C1 [Ashtekar, K.; Roy, A. Sinha; Effat, M.; Helmy, T.; Schneeberger, E.; Banerjee, R.] Univ Cincinnati, Dept Mech Engn, Cincinnati, OH USA. [Kim, E.; Gottliebson, W.] Cincinnati Childrens Hosp, Dept Cardiol, Cincinnati, OH USA. [Back, L.] CALTECH, Jet Prop Lab, Pasadena, CA USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0195-668X J9 EUR HEART J JI Eur. Heart J. PD SEP PY 2008 VL 29 SU 1 BP 77 EP 77 PG 1 WC Cardiac & Cardiovascular Systems SC Cardiovascular System & Cardiology GA V28TG UT WOS:000208702500291 ER PT J AU Mengshoel, OJ Goldberg, DE AF Mengshoel, Ole J. Goldberg, David E. TI The crowding approach to niching in genetic algorithms SO EVOLUTIONARY COMPUTATION LA English DT Article DE genetic algorithms; niching; crowding; deterministic crowding; probabilistic crowding; local tournaments; population sizing; portfolios ID OPTIMIZATION AB A wide range of niching techniques have been investigated in evolutionary and genetic algorithms. In this article, we focus on niching using crowding techniques in the context of what we call local tournament algorithms. In addition to deterministic and probabilistic crowding, the family of local tournament algorithms includes the Metropolis algorithm, simulated annealing, restricted tournament selection, and parallel recombinative simulated annealing. We describe an algorithmic and analytical framework which is applicable to a wide range of crowding algorithms. As an example of utilizing this framework, we present and analyze the probabilistic crowding niching algorithm. Like the closely related deterministic crowding approach, probabilistic crowding is fast, simple, and requires no parameters beyond those of classical genetic algorithms. In probabilistic crowding, subpopulations are maintained reliably, and we show that it is possible to analyze and predict how this maintenance takes place. We also provide novel results for deterministic crowding, show how different crowding replacement rules can be combined in portfolios, and discuss population sizing. Our analysis is backed up by experiments that further increase the understanding of probabilistic crowding. C1 [Mengshoel, Ole J.] NASA, Ames Res Ctr, RIACS, Moffett Field, CA 94035 USA. [Goldberg, David E.] Univ Illinois, Dept Gen Engn, Illinois Genet Algorithms Lab, Urbana, IL 61801 USA. RP Mengshoel, OJ (reprint author), NASA, Ames Res Ctr, RIACS, Mail Stop 269-3, Moffett Field, CA 94035 USA. EM omengshoel@riacs.edu; deg@uiuc.edu FU ONR [N00014-95-1-0749]; ARL [DAAL01-96-2-0003]; NRL [N00014-97-C-2061]; NASA Cooperative Agreement [NCC2-1426]; Air Force Office of Scientific Research, Air Force Materiel Command, USAF [F49620-03-1-0129, AF9550-06-1-0096, AF9550-06-1-0370] FX Dr. Mengshoel's contribution to this work was in part sponsored by ONR Grant N00014-95-1-0749, ARL Grant DAAL01-96-2-0003, NRL Grant N00014-97-C-2061, and NASA Cooperative Agreement NCC2-1426. Professor Goldberg's contribution to this work was sponsored by the Air Force Office of Scientific Research, Air Force Materiel Command, USAF under grants F49620-03-1-0129, AF9550-06-1-0096, and AF9550-06-1-0370. The US Government is authorized to reproduce and distribute reprints for Government purposes notwithstanding any copyright notation thereon.; 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 Air Force Office of Scientific Research or the US Government. NR 46 TC 34 Z9 34 U1 2 U2 11 PU MIT PRESS PI CAMBRIDGE PA 55 HAYWARD STREET, CAMBRIDGE, MA 02142 USA SN 1063-6560 J9 EVOL COMPUT JI Evol. Comput. PD FAL PY 2008 VL 16 IS 3 BP 315 EP 354 DI 10.1162/evco.2008.16.3.315 PG 40 WC Computer Science, Artificial Intelligence; Computer Science, Theory & Methods SC Computer Science GA 353JM UT WOS:000259562600002 PM 18811245 ER PT J AU McCarthy, JL Friedland, KD Brodziak, J AF McCarthy, J. L. Friedland, K. D. Brodziak, J. TI Enhancement of image-based fecundity methods: Gravimetric sampling at sea and safer sample preservation SO FISHERIES RESEARCH LA English DT Article DE Gadus morhua; Melogrammus aeglefinus; Streck Tissue Fixative; fecundity; haddock; image processing; gravimetric sub-sample ID COD GADUS-MORHUA; HADDOCK MELANOGRAMMUS-AEGLEFINUS; ATLANTIC COD; POTENTIAL FECUNDITY; SPAWNING ACTIVITY; OOCYTE DIAMETER; EGG SIZE; GROWTH; INHIBITION; FISH AB Collecting accurate fecundity samples in the field is challenging as field scales are often unreliable and inaccurate in rough seas. In addition, the storage and use of caustic preservatives may be difficult and dangerous. Quantifying the efficacy of both a non-caustic alternative to traditional preservatives, and the use of pre-weighed vials in sampling protocols is essential in improving the accuracy and utility of field samples. Streck Tissue Fixative (STF) is a less toxic alternative to traditional preservatives and proved effective in the short- and long-term preservation of haddock (Melogrammus aeglefinus) and cod oocytes (Gadus morhua). We found no time series trend or systematic change in the number of oocytes counted and there was stabilization in size decay by the second month, which is comparable to traditionally used preservatives. In examining the use of pre-weighed vials we compared several different via] types. Plastic vials with an o-ring showed a satisfactory predictable loss and we were able to develop a system of time dependent corrections for evaporative rate. Thermal effect was also examined, with evaporative loss decreasing at low temperatures. The effectual use of an alternative preservative and the validation of the use of pre-weighed vials have the potential to increase the efficiency and accuracy of field sampling. (c) 2008 Elsevier B.V. All rights reserved. C1 [McCarthy, J. L.] Univ Massachusetts, Dept Nat Resources Conservat, Amherst, MA 01003 USA. [Friedland, K. D.] NOAA, Natl Marine Fisheries Serv, Narragansett, RI 02882 USA. [Brodziak, J.] NOAA, Natl Marine Fisheries Serv, Honolulu, HI 96822 USA. RP McCarthy, JL (reprint author), Univ Massachusetts, Dept Nat Resources Conservat, 160 Holdsworth Way, Amherst, MA 01003 USA. EM oceanjennifer@yahoo.com NR 24 TC 4 Z9 4 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0165-7836 J9 FISH RES JI Fish Res. PD SEP 1 PY 2008 VL 93 IS 1-2 BP 47 EP 53 DI 10.1016/j.fishres.2008.02.006 PG 7 WC Fisheries SC Fisheries GA 345KG UT WOS:000258994700006 ER PT J AU Orphan, VJ Jahnke, LL Embaye, T Turk, KA Pernthaler, A Summons, RE Des Marais, DJ AF Orphan, V. J. Jahnke, L. L. Embaye, T. Turk, K. A. Pernthaler, A. Summons, R. E. Des Marais, D. J. TI Characterization and spatial distribution of methanogens and methanogenic biosignatures in hypersaline microbial mats of Baja California SO GEOBIOLOGY LA English DT Article ID 16S RIBOSOMAL-RNA; METHYLATED SULFUR-COMPOUNDS; DIMETHYL SULFIDE; MARINE-SEDIMENTS; PHYLOGENETIC ANALYSIS; COMMUNITY COMPOSITION; SULFATE REDUCTION; SEQUENCE-ANALYSIS; SOLAR SALTERN; ETHER LIPIDS AB Well-developed hypersaline cyanobacterial mats from Guerrero Negro, Baja California Sur, sustain active methanogenesis in the presence of high rates of sulfate reduction. Very little is known about the diversity and distribution of the microorganisms responsible for methane production in these unique ecosystems. Applying a combination of 16S rRNA and metabolic gene surveys, fluorescence in situ hybridization, and lipid biomarker analysis, we characterized the diversity and spatial relationships of methanogens and other archaea in the mat incubation experiments stimulated with methanogenic substrates. The phylogenetic and chemotaxonomic diversity established within mat microcosms was compared with the archaeal diversity and lipid biomarker profiles associated with different depth horizons in the in situ mat. Both archaeal 16S rRNA and methyl coenzyme M reductase gene (mcrA) analysis revealed an enrichment of diverse methanogens belonging to the Methanosarcinales in response to trimethylamine addition. Corresponding with DNA-based detection methods, an increase in lipid biomarkers commonly synthesized by methanogenic archaea was observed, including archaeol and sn-2-hydroxyarchaeol polar lipids, and the free, irregular acyclic isoprenoids, 2,6,10,15,19-pentamethylicosene (PMI) and 2,6,11,15-tetramethylhexadecane (crocetane). Hydrogen enrichment of a novel putative archaeal polar C(30) isoprenoid, a dehydrosqualane, was also documented. Both DNA and lipid biomarker evidence indicate a shift in the dominant methanogenic genera corresponding with depth in the mat. Specifically, incubations of surface layers near the photic zone predominantly supported Methanolobus spp. and PMI, while Methanococcoides and hydroxyarchaeol were preferentially recovered from microcosms of unconsolidated sediments underlying the mat. Together, this work supports the existence of small but robust methylotrophic methanogen assemblages that are vertically stratified within the benthic hypersaline mat and can be distinguished by both their DNA signatures and unique isoprenoid biomarkers. C1 [Orphan, V. J.; Pernthaler, A.] CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. [Jahnke, L. L.; Embaye, T.; Des Marais, D. J.] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. [Turk, K. A.] SETI Inst, Mountain View, CA 94043 USA. RP Orphan, VJ (reprint author), CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. RI Orphan, Victoria/K-1002-2014 OI Orphan, Victoria/0000-0002-5374-6178 NR 78 TC 33 Z9 33 U1 1 U2 25 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 1472-4677 J9 GEOBIOLOGY JI Geobiology PD SEP PY 2008 VL 6 IS 4 BP 376 EP 393 DI 10.1111/j.1472-4669.2008.00166.x PG 18 WC Biology; Environmental Sciences; Geosciences, Multidisciplinary SC Life Sciences & Biomedicine - Other Topics; Environmental Sciences & Ecology; Geology GA 334YC UT WOS:000258256700005 PM 18564187 ER PT J AU Jahnke, LL Orphan, VJ Embaye, T Turk, KA Kubo, MD Summons, RE Des Marais, DJ AF Jahnke, L. L. Orphan, V. J. Embaye, T. Turk, K. A. Kubo, M. D. Summons, R. E. Des Marais, D. J. TI Lipid biomarker and phylogenetic analyses to reveal archaeal biodiversity and distribution in hypersaline microbial mat and underlying sediment SO GEOBIOLOGY LA English DT Article ID SULFATE-REDUCING BACTERIA; RIBOSOMAL-RNA GENES; MARINE-SEDIMENTS; METHANOGENIC BACTERIA; MEMBRANE-LIPIDS; COMMUNITY STRUCTURE; MASS-SPECTROMETRY; ANOXIC SEDIMENTS; ORGANIC-MATTER; SEA SEDIMENTS AB This study has utilized the tools of lipid biomarker chemistry and molecular phylogenetic analyses to assess the archaeal contribution to diversity and abundance within a microbial mat and underlying sediment from a hypersaline lagoon in Baja California. Based on abundance of ether-linked isoprenoids, archaea made up from 1 to 4% of the cell numbers throughout the upper 100 mm of mat and sediment core. Below this depth archaeal lipid was two times more abundant than bacterial. Archaeol was the primary archaeal lipid in all layers. Relatively small amounts of caldarchaeol (dibiphytanyl glyceroltetraether) were present at most depths with phytanyl to biphytanyl molar ratios lowest (similar to 10 : 1) in the 4-17 mm and 100-130 mm horizons, and highest (132 : 1) in the surface 0-2 mm. Lipids with cyclic biphytanyl cores were only detected below 100 mm. A novel polar lipid containing a C(30) isoprenoid (squalane) moiety was isolated from the upper anoxic portion of the core and partially characterized. Hydrocarbon biomarker lipids included pentamethylicosane (2-10 mm) and crocetane (primarily below 10 mm). Archaeal molecular diversity varied somewhat with depth. With the exception of samples at 0-2 mm and 35-65 mm, Thermoplasmatales of marine benthic group D dominated clone libraries. A significant number of phylotypes representing the Crenarchaeota from marine benthic group B were generally present below 17 mm and dominated the 35-65 mm sample. Halobacteriaceae family made up 80% of the clone library of the surface 2 mm, and consisted primarily of sequences affiliated with the haloalkaliphilic Natronomonas pharaonis. C1 [Jahnke, L. L.; Orphan, V. J.; Des Marais, D. J.] NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. [Jahnke, L. L.; Summons, R. E.; Des Marais, D. J.] NASA, Astrobiol Inst, Moffett Field, CA 94035 USA. [Orphan, V. J.] CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. [Embaye, T.; Turk, K. A.; Kubo, M. D.] SETI Inst, Carl Sagan Ctr, Mountain View, CA 94043 USA. [Summons, R. E.] MIT, Dept Earth Atmospher & Planetary Sci, Cambridge, MA 02139 USA. RP Jahnke, LL (reprint author), NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. RI Orphan, Victoria/K-1002-2014 OI Orphan, Victoria/0000-0002-5374-6178 NR 98 TC 29 Z9 30 U1 2 U2 25 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 1472-4677 J9 GEOBIOLOGY JI Geobiology PD SEP PY 2008 VL 6 IS 4 BP 394 EP 410 DI 10.1111/j.1472-4669.2008.00165.x PG 17 WC Biology; Environmental Sciences; Geosciences, Multidisciplinary SC Life Sciences & Biomedicine - Other Topics; Environmental Sciences & Ecology; Geology GA 334YC UT WOS:000258256700006 PM 18564188 ER PT J AU Motagh, M Wang, RJ Walter, TR Burgmann, R Fielding, E Anderssohn, J Zschau, J AF Motagh, Mahdi Wang, Rongjiang Walter, Thomas R. Buergmann, Roland Fielding, Eric Anderssohn, Jan Zschau, Jochen TI Coseismic slip model of the 2007 August Pisco earthquake (Peru) as constrained by Wide Swath radar observations SO GEOPHYSICAL JOURNAL INTERNATIONAL LA English DT Article DE radar interferometry; earthquake source observations; continental margins; convergent ID 12 NOVEMBER 1996; DEFORMATION; SPACE; ANDES; INSAR AB The Pisco earthquake (M(w) 8.0; 2007 August 15) occurred offshore of Peru's southern coast at the subduction interface between the Nazca and South American plates. It ruptured a previously identified seismic gap along the Peruvian margin. We use Wide Swath InSAR observations acquired by the Envisat satellite in descending and ascending orbits to constrain coseismic slip distribution of this subduction earthquake. The data show movement of the coastal regions by as much as 85 cm in the line-of-sight of the satellite. Distributed-slip model indicates that the coseismic slip reaches values of about 5.5 m at a depth of similar to 18-20 km. The slip is confined to less than 40 km depth, with most of the moment release located on the shallow parts of the interface above 30 km depth. The region with maximum coseismic slip in the InSAR model is located offshore, close to the seismic moment centroid location. The geodetic estimate of seismic moment is 1.23 x 10(21) Nm (M(w) 8.06), consistent with seismic estimates. The slip model inferred from the InSAR observations suggests that the Pisco earthquake ruptured only a portion of the seismic gap zone in Peru between 13.5 degrees S and 14.5 degrees S, hence there is still a significant seismic gap to the south of the 2007 event that has not experienced a large earthquake since at least 1687. C1 [Motagh, Mahdi; Wang, Rongjiang; Walter, Thomas R.; Zschau, Jochen] Geoforschungszentrum Potsdam, Dept Earthquake Risk & Early Warning, D-14473 Potsdam, Germany. [Buergmann, Roland] Univ Calif Berkeley, Dept Earth & Planetary Sci, Berkeley, CA 94720 USA. [Buergmann, Roland] Univ Calif Berkeley, Berkeley Seismol Lab, Berkeley, CA 94720 USA. [Fielding, Eric] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Anderssohn, Jan] Geoforschungszentrum Potsdam, Dept Remote Sensing, D-14473 Potsdam, Germany. RP Motagh, M (reprint author), Geoforschungszentrum Potsdam, Dept Earthquake Risk & Early Warning, D-14473 Potsdam, Germany. RI Walter, Thomas/K-4857-2015; Fielding, Eric/A-1288-2007 OI Fielding, Eric/0000-0002-6648-8067 FU German Research Foundation (DFG) [MO1851/1-1]; California Institute of Technology; NASA; European Space Agency [AOALO 3740] FX This work was supported by the German Research Foundation (DFG) through a research fellowship to Mahdi Motagh(MO1851/1-1). Part of the research described in this paper was carried out at the Jet Propulsion Laboratory (JPL), California Institute of Technology, under a contract with NASA. Some of the figures were prepared using the public domain GMT software (Wessel & Smith 1998). We thank Martin Vallee for providing us with his slip model, Manoochehr Shirzaei for discussions and Kevin Fleming for his comments on the manuscript. We are grateful to Kaj Johnson and an anonymous reviewer for their thoughtful review and appreciate constructive comments by the Editor, John Beavan. Envisat wide swath data were provided by the European Space Agency via category-1 proposal AOALO 3740. NR 20 TC 22 Z9 23 U1 0 U2 5 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0956-540X J9 GEOPHYS J INT JI Geophys. J. Int. PD SEP PY 2008 VL 174 IS 3 BP 842 EP 848 DI 10.1111/j.1365-246X.2008.03852.x PG 7 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 340ZV UT WOS:000258684400006 ER PT J AU Molholt, TE Gunnlaugsson, H Merrison, J Morris, R Nornberg, P AF Molholt, T. E. Gunnlaugsson, H. P. Merrison, J. P. Morris, R. V. Nornberg, P. TI Mossbauer and VNIR study of dust generated from olivine basalt: application to Mars SO HYPERFINE INTERACTIONS LA English DT Article DE Olivine basalt; VNIR study; Pyroxene; Mossbauer spectroscopy ID REFLECTANCE; MINERALOGY; PYROXENES; MODEL AB Mossbauer spectroscopy of surface rocks, soil, and dust on Mars from the Mars Exploration Rovers (MER) suggests that the mineral olivine is widespread on the surface. Detection of the mineral by near-IR optical spectroscopy from Martian orbit indicates that it is found in relatively small isolated outcrops concentrated in the floors and rims of craters distributed around the ancient cratered highlands of Mars. To shed light on this apparent paradox, we have performed a detailed Mossbauer and visible-near-IR (VNIR) investigation of dust generated from Icelandic olivine basalt, which is a good Mossbauer analogue to the igneous rocks at Gusev crater on Mars. The results show that the amount of olivine relative to pyroxene can be underestimated by almost an order of a magnitude in VNIR reflectance spectra, most probably because of the longer effective optical path length in pyroxene compared to olivine. C1 [Molholt, T. E.; Gunnlaugsson, H. P.] Aarhus Univ, Dept Phys & Astron, DK-8000 Aarhus C, Denmark. [Merrison, J. P.] Aarhus Univ, Inst Phys & Astron, DK-8000 Aarhus, Denmark. [Morris, R. V.] NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. [Nornberg, P.] Aarhus Univ, Dept Earth Sci, DK-8000 Aarhus, Denmark. RP Gunnlaugsson, H (reprint author), Aarhus Univ, Dept Phys & Astron, DK-8000 Aarhus C, Denmark. EM hpg@phys.au.dk RI Nornberg, Per/A-6228-2012; OI merrison, jonathan/0000-0003-4362-6356; Molholt, Torben Esmann/0000-0002-4288-0128 NR 17 TC 2 Z9 2 U1 0 U2 4 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0304-3843 J9 HYPERFINE INTERACT JI Hyperfine Interact. PD SEP PY 2008 VL 186 IS 1-3 BP 127 EP 133 DI 10.1007/s10751-008-9842-2 PG 7 WC Physics, Atomic, Molecular & Chemical; Physics, Condensed Matter; Physics, Nuclear SC Physics GA 374RR UT WOS:000261061900017 ER PT J AU Fleischer, I Klingelhofer, G Schroder, C Rodionov, DS AF Fleischer, Iris Klingelhoefer, Goestar Schroeder, Christian Rodionov, Daniel S. TI Coatings and weathering rinds at Gusev crater, Mars, investigated by depth selective Mossbauer spectroscopy SO HYPERFINE INTERACTIONS LA English DT Article DE Depth selective Mossbauer spectroscopy; Mars Exploration Rover mission; Iron mineralogy; Geochemistry AB The miniaturised Mossbauer spectrometer (MIMOS II) is part of the scientific payload of the two Mars Exploration Rovers, "Spirit" and "Opportunity" (Klingelhofer et al., J Geophys Res 108(E12), 2003). MIMOS II can obtain 14.4 keV gamma-ray spectra and 6.4 keV X-ray spectra simultaneously in backscattering geometry. Comparing 6.4 keV and 14.4 keV spectra yields depth selective information about a sample and allows for the detection and characterization of thin coatings or weathering rinds. Laboratory measurements and a Monte Carlo simulation were used to study the influence of coatings of varying thickness and composition on backscattering Mossbauer spectra. The thickness of thin surface layers on natural samples can be estimated by comparing measured and the corresponding simulated spectra. C1 [Fleischer, Iris; Klingelhoefer, Goestar; Rodionov, Daniel S.] Johannes Gutenberg Univ Mainz, Inst Anorgan & Analyt Chem, D-55099 Mainz, Germany. [Schroeder, Christian] NASA, Lyndon B Johnson Space Ctr, KR, Houston, TX 77058 USA. [Rodionov, Daniel S.] Space Res Inst IKI, Moscow, Russia. RP Fleischer, I (reprint author), Johannes Gutenberg Univ Mainz, Inst Anorgan & Analyt Chem, Staudinger Weg 9, D-55099 Mainz, Germany. EM fleischi@uni-mainz.de; klingel@mail.uni-mainz.de; christian.schroeder-1@nasa.gov; rodionov@iki.rssi.ru RI Schroder, Christian/B-3870-2009 OI Schroder, Christian/0000-0002-7935-6039 NR 8 TC 4 Z9 4 U1 0 U2 1 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0304-3843 J9 HYPERFINE INTERACT JI Hyperfine Interact. PD SEP PY 2008 VL 186 IS 1-3 BP 193 EP 198 DI 10.1007/s10751-008-9853-z PG 6 WC Physics, Atomic, Molecular & Chemical; Physics, Condensed Matter; Physics, Nuclear SC Physics GA 374RR UT WOS:000261061900027 ER PT J AU Purucker, ME AF Purucker, Michael E. TI A global model of the internal magnetic field of the Moon based on Lunar Prospector magnetometer observations SO ICARUS LA English DT Article DE Moon, interior; Moon, surface; magnetic fields; magnetospheres ID ANOMALIES; SURFACE AB A preliminary model of the internal magnetic field of the Moon is developed using a novel. correlative technique on the low-altitude Lunar Prospector magnetic field observations. Subsequent to the removal of a simple model of the external field, an internal dipole model is developed for each pole-to-pole half-orbit. This internal dipole model exploits Lunar Prospector's orbit geometry and incorporates radial and theta vector component data from immediately adjacent passes into the model. These adjacent passes are closely separated in space and time and are thus characteristic of a particular lunar regime (wake, solar wind, magnetotail, magnetosheath) or regimes. Each dipole model thus represents the correlative parts of three adjacent passes, and provides an analytic means of continuing the data to a constant surface of 30 km above the mean lunar radius. The altitude-normalized radial field from the wake and tail regimes is used to build a model in which 99.2% of the 360 by 360 bins covering the lunar surface are filled. This global model of the radial magnetic field is used to construct a degree 178 spherical harmonic model of the field via the Driscoll and Healy sampling theorem. Terms below about degree 150 are robust, and polar regions are considered to be the least reliable. The model resolves additional detail in the low magnetic field regions of the Imbrium and Orientale basins, and also in the four anomaly clusters antipodal to the large lunar basins. The model will be of use in understanding the sources of the internal field, and as a first step in modeling the interaction of the internal field with the solar wind. (C) 2008 Elsevier Inc. All rights reserved. C1 Goddard Space Flight Ctr, Raytheon Planetary Geodynam Lab, Greenbelt, MD 20771 USA. RP Purucker, ME (reprint author), Goddard Space Flight Ctr, Raytheon Planetary Geodynam Lab, Code 698, Greenbelt, MD 20771 USA. EM michael.e.purucker@nasa.gov FU NASA's Discovery Data Analysis Program FX I thank NASA's Discovery Data Analysis Program for support of this research, T.J. Sabaka for the external field model, M. Wieczorek for SHTOOLS, and P. Wessel and W. Smith for GMT. Comments by N. Richmond, M. Wieczorek, J. Halekas, B. Langlais, and an anonymous reviewer were very helpful. NR 27 TC 48 Z9 50 U1 0 U2 6 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 SEP PY 2008 VL 197 IS 1 BP 19 EP 23 DI 10.1016/j.icarus.2008.03.016 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 347OV UT WOS:000259151800002 ER PT J AU Manning, CV Mckay, CP Zahnle, KJ AF Manning, Curtis V. McKay, Christopher P. Zahnle, Kevin J. TI The nitrogen cycle on Mars: Impact decomposition of near-surface nitrates as a source for a nitrogen steady state SO ICARUS LA English DT Article DE Mars, atmosphere; Mars, surface; atmospheres, evolution; impact processes ID ISOTOPE FRACTIONATION; MARTIAN ATMOSPHERE; CRATERING RATE; ESCAPE; METEORITES; VOLATILES; EVOLUTION AB Nitrogen isotopes appear to be escaping from Mars at approximately the Primordial ratio N-14/N-15 approximate to 275 and to have an atmospheric nitrogen depletion time scale of about 800 Myr. For the standard model of a Progressive decline of an initial inventory of atmospheric nitrogen, having no source of N, the agreement of the isotopic ratio of escaping N with primitive nitrogen would be coincidental. Here we propose a steady state model in which nitrates, produced early in Mars' history, are later decomposed by the Current impact flux. The detection of near-surface nitrates can discriminate between the standard and the steady state models. Based on current estimates of N loss to space, we predict a quantity of nitrates equivalent to 60 +/- 30 mbars for a steady state, or a global layer of about 3 m of pore NaNO3. Published by Elsevier Inc. C1 [Manning, Curtis V.; McKay, Christopher P.; Zahnle, Kevin J.] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Manning, CV (reprint author), NASA, Ames Res Ctr, MS 245-3, Moffett Field, CA 94035 USA. EM cmanning@arc.nasa.gov NR 26 TC 15 Z9 15 U1 2 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 J9 ICARUS JI Icarus PD SEP PY 2008 VL 197 IS 1 BP 60 EP 64 DI 10.1016/j.icarus.2008.04.015 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 347OV UT WOS:000259151800006 ER PT J AU Hodyss, R Goguen, JD Johnson, PV Campbell, C Kanik, I AF Hodyss, Robert Goguen, Jay D. Johnson, Paul V. Campbell, Colin Kanik, Isik TI Release of N-2, CH4, CO2, and H2O from surface ices on Enceladus SO ICARUS LA English DT Article DE ices; satellite, surfaces; Enceladus; atmospheres, composition ID AMORPHOUS WATER ICE; VAPOR PLUME; CASSINI; MOLECULES; DESORPTION; NITROGEN AB We vapor deposit at 20 K a Mixture of gases with the specific Enceladus plume composition measured in situ by the Cassini INMS [Waite, J.H., Combi, M.R., Ip, W.H.. Cravens, T.E., McNutt, R.L., Kasprzak, W., Yelle. R., Luhmann, J., Niemann, H., Gell, D., Magee, B., Fletcher, G., Lunine, J., Tseng, W.L., 2006. Science 311, 1419-1422] to form a mixed molecular ice. As the sample is slowly warmed, we monitor the escaping gas quantity and composition with a mass spectrometer. Pioneering Studies (Schmitt, B., Klinger, J., 1987. Different trapping mechanisms of gases by water ice and their relevance for comet nuclei. In: Rolfe, E.J., Battrick. B. (Eds.), Diversity and Similarity of Comets. SP-278. ESA, Noordwijk, The Netherlands, pp. 613619; Bar-Nun, A., Kleinfeld, I., Kochavi, E., 1988. Phys. Rev. B 38. 7749-7754; Bar-Nun, A., Kleinfeld, I., 1989. Icarus 80, 243-253] have shown that significant quantities of volatile gases can be trapped in a water ice matrix well above the temperature at which the pure volatile ice would sublime. For our Enceladus ice Mixture, a composition of escaping gases similar to that detected by Cassini in the Enceladus plume can be generated by the sublimation of the H2O:CO2:CH4:N-2 mixture at temperatures between 135 and 155 K, comparable to the high temperatures inferred from the CIRS measurements [Spencer, J.R., Pearl, J.C., Segura, M., Flasar, F.M., Mamoutkine, A., Romani, P., Buratti, B.J., Hendrix, A.R., Spilker, L.J., Lopes, R.M.C., 2006. Science 311, 1401-1405] of the Enceladus "tiger stripes." This suggests that the gas escape phenomena that we measure in our experiments are an important process contributing to the gases emitted from Enceladus. A similar experiment for ice deposited at 70 K shows that both the processes of volatile trapping and release are temperature dependent over the temperature range relevant to Enceladus. (C) 2008 Elsevier Inc. All Fights reserved. C1 [Hodyss, Robert; Goguen, Jay D.; Johnson, Paul V.; Campbell, Colin; Kanik, Isik] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Hodyss, R (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,Mail Stop 183-601, Pasadena, CA 91109 USA. EM robert.p.hodyss@jpl.nasa.gov RI Johnson, Paul/D-4001-2009; Campbell, Colin/E-2179-2014 OI Johnson, Paul/0000-0002-0186-8456; NR 22 TC 6 Z9 6 U1 2 U2 12 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 SEP PY 2008 VL 197 IS 1 BP 152 EP 156 DI 10.1016/j.icarus.2008.03.023 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 347OV UT WOS:000259151800012 ER PT J AU Bailey, J Meadows, VS Chamberlain, S Crisp, D AF Bailey, Jeremy Meadows, V. S. Chamberlain, S. Crisp, D. TI The temperature of the Venus mesosphere from O-2 (a(1) Delta(g)) airglow observations SO ICARUS LA English DT Article DE Venus, atmosphere; spectroscopy; atmospheres, structure ID NEAR-INFRARED OBSERVATIONS; MOLECULAR-OXYGEN; UPPER-ATMOSPHERE; LOWER THERMOSPHERE; MIDDLE ATMOSPHERE; SPECTROSCOPY; ABSORPTION; NIGHTSIDE; DYNAMICS; EXPRESS AB We have used near-infrared spectroscopic observations of the Venus nightside taken with the Infrared Imager and Spectrograph 2 (IRIS2) on the Anglo-Australian Telescope to derive temperature maps for the Venus mesosphere at an altitude of similar to 95 km. The temperatures are derived from the distribution of rotational line intensities in the O-2 (a(1) Delta(g)) airglow band at 1.27 mu m. To obtain reliable temperatures at the relatively low spectral resolution of IRIS2, we have developed a forward modeling approach to handle the blending of individual O-2 lines and the telluric absorption in the same O-2 band. The technique provides temperature retrievals with accuracy comparable to, or better than that of previous high-spectral resolution determinations. The resulting temperature maps show spatial temperature structure that varies from night to night, as does the intensity distribution. Intensity weighted mean temperatures range from about 181 to 196 K. The temperatures are typically 15-30 K higher than those expected from the Venus International Reference Atmosphere (VIRA) profile. The temperatures fall in regions of low O-2 emission rate to values closer to the VIRA levels. Our temperatures are similar to, but slightly lower than those obtained from stellar occultation measurements with SPICAV on Venus Express. We suggest that we are seeing a region of locally enhanced temperature caused by compressional heating in the downwelling gas around the antisolar point. (C) 2008 Elsevier Inc. All rights reserved. C1 [Bailey, Jeremy; Chamberlain, S.] Macquarie Univ, Dept Phys, Sydney, NSW 2109, Australia. [Meadows, V. S.] Univ Washington, Dept Astron, Seattle, WA 98195 USA. [Crisp, D.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Bailey, J (reprint author), Macquarie Univ, Dept Phys, Sydney, NSW 2109, Australia. EM jbailey@els.mq.edu.au FU NASA Astrobiology Institute's Virtual Planetary Laboratory Lead Team; National Aeronautics and Space Administration [CAN-00-OSS-01]; Jet Propulsion Laboratory; California Institute of Technology; National Aeronautics and Space Administration FX This work was supported by the NASA Astrobiology Institute's Virtual Planetary Laboratory Lead Team, funded by the National Aeronautics and Space Administration through the NASA Astrobiology Institute under Cooperative Agreement No. CAN-00-OSS-01. Part of this work was performed at the Jet Propulsion Laboratory, California Institute of Technology, under contract to the National Aeronautics and Space Administration. We thank the AAO staff for support of the observations at the Anglo-Australian Telescope. We thank Andrew Orr-Ewing and Colin Western (University of Bristol) for the PGOPHER software and O2 transition data. NR 36 TC 33 Z9 33 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 J9 ICARUS JI Icarus PD SEP PY 2008 VL 197 IS 1 BP 247 EP 259 DI 10.1016/j.icarus.2008.04.007 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 347OV UT WOS:000259151800021 ER PT J AU Mastrapa, RM Bernstein, MP Sandford, SA Roush, TL Cruikshank, DP Ore, CMD AF Mastrapa, R. M. Bernstein, M. P. Sandford, S. A. Roush, T. L. Cruikshank, D. P. Ore, C. M. Dalle TI Optical constants of amorphous and crystalline H2O-ice in the near infrared from 1.1 to 2.6 mu m SO ICARUS LA English DT Article DE ices; ices, IR spectroscopy; experimental techniques ID WATER-ICE; SOLID WATER; H2O ICE; INDUCED AMORPHIZATION; ABSORPTION-SPECTRUM; ION IRRADIATION; SOLAR-SYSTEM; DENSITY; REGION; RANGE AB Using new laboratory spectra, we have calculated the real and imaginary parts of the index of refraction of amorphous and crystalline H2O-ice from 20 to 150 K in the frequency range 9000-3800 cm(-1) (1.1-2.6 pin) at a spectral resolution of 1 cm(-1). These optical constants can be used to create model spectra for comparison to spectra from Solar System objects. We also analyzed the differences between the amorphous and crystalline H2O-ice spectra, including weakening of bands and shifting of bands to shorter wavelength in amorphous H2O-ice spectra. We have also observed two spectrally distinct phases of amorphous H2O-ice. (C) 2008 Elsevier Inc. All rights reserved. C1 [Mastrapa, R. M.; Bernstein, M. P.; Sandford, S. A.; Roush, T. L.; Cruikshank, D. P.; Ore, C. M. Dalle] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. [Mastrapa, R. M.; Ore, C. M. Dalle] SETI Inst, Mountain View, CA 94043 USA. RP Mastrapa, RM (reprint author), NASA, Ames Res Ctr, MS 245-6, Moffett Field, CA 94035 USA. EM rachel.m.mastrapa@nasa.gov FU Planetary Geology and Geophysics Program [05-PGG05-41]; Origins of the Solar System Program; NASA Postdoctoral Program FX We acknowledge financial support from the following programs: Planetary Geology and Geophysics Program (05-PGG05-41), Origins of the Solar System Program, and NASA Postdoctoral Program. NR 48 TC 46 Z9 46 U1 1 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 J9 ICARUS JI Icarus PD SEP PY 2008 VL 197 IS 1 BP 307 EP 320 DI 10.1016/j.icarus.2008.04.008 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 347OV UT WOS:000259151800026 ER PT J AU Cloutis, EA McCormack, KA Bell, JF Hendrix, AR Bailey, DT Craig, MA Mertzman, SA Robinson, MS Riner, MA AF Cloutis, Edward A. McCormack, Kaitlyn A. Bell, James F., III Hendrix, Amanda R. Bailey, Daniel T. Craig, Michael A. Mertzman, Stanley A. Robinson, Mark S. Riner, Miriam A. TI Ultraviolet spectral reflectance properties of common planetary minerals SO ICARUS LA English DT Review DE ultraviolet observations; spectroscopy; Moon, surface; spectroscopy; Mars, surface ID ELECTRONIC ABSORPTION-SPECTRA; DIFFUSE REFLECTANCE; OPTICAL-ABSORPTION; MU-M; IMAGING SPECTROSCOPY; OMEGA/MARS EXPRESS; CRYSTAL-CHEMISTRY; HERMEAN REGOLITH; EMISSION-SPECTRA; MARTIAN DUST AB Ultraviolet spectral reflectance properties (200-400 nm) of a large number of minerals known or presumed to exist on the surfaces of Mars, the Moon, and asteroids, and in many meteorites, were investigated. Ultraviolet reflectance spectra (200-400 nm) of these minerals range from slightly blue-sloped (reflectance decreasing toward longer wavelengths) to strongly red-sloped (reflectance increasing toward longer wavelengths). Most exhibit one or two absorption features that are attributable to Fe-O charge transfers involving Fe3+ or Fe2+. The UV region is a very sensitive indicator of the presence of even trace amounts (<0.01 wt%) of Fe3+ and Fe2+. The major Fe3+-O absorption band occurs at shorter wavelengths (similar to 210-230 nm), and is more intense than the major Fe2+-O absorption band (similar to 250-270 nm). Ti-bearing minerals, such as ilmenite, rutile and anatase exhibit UV absorption bands attributable to Ti4+-O charge transfers. While the positions of metal-O charge transfer bands sometimes differ for different minerals. the variation is often not diagnostic enough to permit unique mineral identification. However, iron oxides and oxyhydroxides can generally be distinguished from Fe-bearing silicates in the 200-400 nm region on the basis of absorption band positions. Within a given mineral group (e.g., low-calcium pyroxene, olivine, plagioclase feldspar), changes in Fe2+ or Fe3+ abundance do not appear to result in a measurable change in absorption band minima positions. Absorption band positions can vary as a function of grain size, however, and this variation is likely due to band Saturation effects. The intensity of metal-O charge transfers means that some minerals will exhibit saturated UV absorption bands even for fine-grained (<45 mu m) powders. In cases where absorption bands are not saturated (e.g., Fe2+-O bands in some plagioclase feldspars and pyroxenes), changes in Fe2+ content do not appear to cause variations in band position. In other minerals (e.g., olivine), changes in band positions are correlated with compositional and/or grain size variations, but this is likely due to increasing band saturation rather than compositional variations. Overall, we find that the UV spectral region is sensitive to different mineral properties than longer wavelength regions, and thus offers the potential to provide complementary capabilities and unique opportunities for planetary remote sensing. (C) 2008 Elsevier Inc. All rights reserved. C1 [Cloutis, Edward A.; McCormack, Kaitlyn A.; Bailey, Daniel T.; Craig, Michael A.] Univ Winnipeg, Dept Geog, Winnipeg, MB R3B 2E9, Canada. [Bell, James F., III] Cornell Univ, Dept Astron, Ithaca, NY 14853 USA. [Hendrix, Amanda R.] Jet Prop Lab, Pasadena, CA 91109 USA. [Mertzman, Stanley A.] Franklin & Marshall Coll, Dept Earth & Environm, Lancaster, PA 17604 USA. [Robinson, Mark S.; Riner, Miriam A.] Arizona State Univ, Sch Earth & Space Explorat, Tempe, AZ 85287 USA. RP Cloutis, EA (reprint author), Univ Winnipeg, Dept Geog, 515 Portage Ave, Winnipeg, MB R3B 2E9, Canada. EM e.cloutis@uwinnipeg.ca NR 145 TC 41 Z9 41 U1 1 U2 24 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 SEP PY 2008 VL 197 IS 1 BP 321 EP 347 DI 10.1016/j.icarus.2008.04.018 PG 27 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 347OV UT WOS:000259151800027 ER PT J AU Lucey, PG Noble, SK AF Lucey, Paul G. Noble, Sarah K. TI Experimental test of a radiative transfer model of the optical effects of space weathering SO ICARUS LA English DT Article DE Moon, surface; mercury; spectroscopy ID LUNAR REGOLITH; FINEST FRACTION; VAPOR DEPOSITS; IRON; MERCURY; SAMPLES; MOON; SOIL AB We compare laboratory measurements of the optical effects of nanophase iron on near-IR reflectance spectra of transparent silica gel infused with small iron particles [Noble, S.K., Pieters, C.M., Keller, L.P., 2007. Icarus 192, 629-642] with a radiative transfer model of the process [Hapke, B., 2001. J. Geophys. Res. 106 (E5), 10039-10074]. We find that the measurements exhibit reddening and darkening effects of nanophase (<50 nm) iron particles, a darkening effect of somewhat larger particles (>50 nm) and mixing effects of silica gel particles of varying total iron abundance. The radiative transfer model reproduces the effects of nanophase iron within the experimental uncertainties. (C) 2008 Elsevier Inc. All rights reserved. C1 [Lucey, Paul G.] Univ Hawaii Manoa, Hawaii Inst Geophys & Planteol, Honolulu, HI 96822 USA. [Noble, Sarah K.] NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. RP Lucey, PG (reprint author), Univ Hawaii Manoa, Hawaii Inst Geophys & Planteol, Honolulu, HI 96822 USA. EM lucey@higp.hawaii.edu; sarah.k.noble@nasa.gov RI Noble, Sarah/D-7614-2012 FU NASA [NGT9-66, NNG05GJ-51G, NAG5-13609]; ORAU FX We thank Takahiro Hiroi and an anonymous reviewer for very constructive comments. NASA support (NGT9-66, SKN; NNG05GJ-51G PGL) is gratefully acknowledged, as is Support for SKN from ORAU through the NASA Postdoctoral Program. All laboratory spectra were acquired using RELAB, a multi-user facility Supported by NASA under NAG5-13609. This is SOEST Publication No. 7468; and HIGP Publication No. 1663. NR 36 TC 29 Z9 29 U1 2 U2 6 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 SEP PY 2008 VL 197 IS 1 BP 348 EP 353 DI 10.1016/j.icarus.2008.05.008 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 347OV UT WOS:000259151800028 ER PT J AU Busch, MW Benner, LAM Ostro, SJ Giorgini, JD Jurgens, RF Rose, R Scheeres, DJ Magri, C Margot, JL Nolan, MC Hine, AA AF Busch, Michael W. Benner, Lance A. M. Ostro, Steven J. Giorgini, Jon D. Jurgens, Raymond F. Rose, Randy Scheeres, Daniel J. Magri, Christopher Margot, Jean-Luc Nolan, Michael C. Hine, Alice A. TI Physical properties of near-Earth Asteroid (33342) 1998 WT24 (vol 195, pg 614, 2008) SO ICARUS LA English DT Correction C1 [Busch, Michael W.] CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. [Benner, Lance A. M.; Ostro, Steven J.; Giorgini, Jon D.; Jurgens, Raymond F.; Rose, Randy] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Scheeres, Daniel J.] Univ Michigan, Dept Aerosp Engn, Ann Arbor, MI 48109 USA. [Magri, Christopher] Univ Maine, Farmington, ME 04938 USA. [Margot, Jean-Luc] Cornell Univ, Dept Astron, Ithaca, NY 14853 USA. [Nolan, Michael C.; Hine, Alice A.] Natl Astron & Ionosphere Ctr, Arecibo Observ, Arecibo, PR 00613 USA. RP Busch, MW (reprint author), CALTECH, Div Geol & Planetary Sci, MC 150-21, Pasadena, CA 91125 USA. EM busch@caltech.edu 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 NR 1 TC 0 Z9 0 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 J9 ICARUS JI Icarus PD SEP PY 2008 VL 197 IS 1 BP 375 EP 375 DI 10.1016/j.icarus.2008.06.004 PG 1 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 347OV UT WOS:000259151800031 ER PT J AU Reinholtz, K Patel, K AF Reinholtz, Kirk Patel, Keyur TI Testing autonomous systems for deep space exploration SO IEEE AEROSPACE AND ELECTRONIC SYSTEMS MAGAZINE LA English DT Article AB NASA is moving into an era of increasing spacecraft autonomy. However, before autonomy can be routinely utilized, we must develop techniques for providing assurance that the system will perform correctly in flight. We describe why autonomous systems require advanced verification techniques, and offer some management and technical techniques for addressing the differences. Autonomous goal-driven spacecraft require advances in verification techniques because optimization (e.g., planning and scheduling) algorithms are at the core of much of autonomy. It is the nature of such algorithms that over much of the input space an intuitively "small" change in the input results in a correspondingly "small" change in the output: This type of response typically leads one to conclude, quite reasonably, that if the two responses are correct, those responses "between" them will probably also be correct. However, there are certain regions in the input space where a "small" change in the input will result in a radically different output: One is not so inclined to conclude that all responses in these transition zones are likely to be correct. We believe, for two reasons, that these transition zones are one place where autonomous systems are likely to fail. First, boundary conditions, often a rich source of faults, are highly exercised in the transition zones, and so increase the likelihood of faults. Second, within the transition zone the algorithm outputs are likely to appear unusual, and, since the outputs of the algorithm become inputs to the remainder of the system, the whole system is probably pushed outside of its nominal usage profile: historically shown to be another good source of faults. We close with a discussion of risk management. Autonomous systems have many well-known management risk factors. Risk management and quality concerns must be pervasive, throughout all team members and the whole life-cycle of the project. C1 [Reinholtz, Kirk; Patel, Keyur] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Reinholtz, K (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 303-310, Pasadena, CA 91109 USA. NR 14 TC 1 Z9 1 U1 1 U2 3 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 SEP PY 2008 VL 23 IS 9 BP 22 EP 27 DI 10.1109/MAES.2008.4635067 PG 6 WC Engineering, Aerospace; Engineering, Electrical & Electronic SC Engineering GA 356RX UT WOS:000259796400003 ER PT J AU Hepp, AF McNatt, JS Bailey, SG Raffaelle, RP Landi, BJ Sun, SS Bonner, CE Banger, KK Rauh, D AF Hepp, Aloysius F. McNatt, Jeremiah S. Bailey, Sheila G. Raffaelle, Ryne P. Landi, Brian J. Sun, Sam-S. Bonner, Carl E. Banger, Kulbinder K. Rauh, David TI Ultra-lightweight space power from hybrid thin-film solar cells SO IEEE AEROSPACE AND ELECTRONIC SYSTEMS MAGAZINE LA English DT Article ID SINGLE-SOURCE PRECURSORS; PHOTOINDUCED ELECTRON-TRANSFER; ORGANIC PHOTOVOLTAIC CELL; WALLED CARBON NANOTUBES; BLOCK-COPOLYMER; EFFICIENCY; POLYMERS; ROUTE; SEMICONDUCTORS; NANOPARTICLES AB The development of hybrid inorganic/organic thin-filin solar cells on flexible, lightweight, space-qualified, durable substrates provides an attractive solution for space power generation with high mass specific power (W/kg). The high-volume, low-cost fabrication potential of organic cells will allow for square miles of solar cell production at one-tenth the cost of conventional inorganic materials. Plastic solar cells take a minimum of storage space and can be inflated or unrolled for deployment. We explore a cross-section of NASA in-house and sponsored research efforts that aim to provide new hybrid technologies that include both inorganic and polymer materials as active and substrate materials. For NASA applications, any solar cell or array technology must not only meet weight and AMO efficiency goals, but also must be durable enough to survive launch and space environments. Also, balance of system technologies must be developed to take advantage of ultra-lightweight solar arrays in power generation systems. C1 [Hepp, Aloysius F.; McNatt, Jeremiah S.; Bailey, Sheila G.] NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. [Raffaelle, Ryne P.; Landi, Brian J.] Rochester Inst Technol, Dept Phys, Rochester, NY 14623 USA. [Raffaelle, Ryne P.; Landi, Brian J.] Rochester Inst Technol, NanoPower Res Lab, Rochester, NY 14623 USA. [Sun, Sam-S.; Bonner, Carl E.] Norfolk State Univ, Dept Chem, Norfolk, VA 23504 USA. [Banger, Kulbinder K.] Ohio Aerosp Inst, Brookpark, OH 44142 USA. [Rauh, David] EIC Labs Inc, Norwood, MA 02062 USA. RP Hepp, AF (reprint author), NASA, Glenn Res Ctr, MS 302-1,21000 Brookpk Rd, Cleveland, OH 44135 USA. FU NASA Glenn Research Center FX The authors gratefully acknowledge NASA Glenn Research Center for their financial support. We thank Jon Cowen (Case Western Reserve University), Prof. Jung-II Jin (Korea University), Dr. Krishna Mandal (EIC Laboratories, Inc.), Prof. John Reynolds (University of Florida), and David Scheiman (Essential Research, Inc.) for samples, measurements, and/or technical discussions. NR 47 TC 0 Z9 0 U1 3 U2 8 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 SEP PY 2008 VL 23 IS 9 BP 31 EP 41 DI 10.1109/MAES.2008.4635069 PG 11 WC Engineering, Aerospace; Engineering, Electrical & Electronic SC Engineering GA 356RX UT WOS:000259796400005 ER PT J AU Choi, KK Jhabvala, MD Peralta, RJ AF Choi, Kwong-Kit Jhabvala, Murzy D. Peralta, Richard J. TI Voltage-tunable two-color corrugated-QWIP focal plane arrays SO IEEE ELECTRON DEVICE LETTERS LA English DT Article DE infrared detectors; infrared image sensors; quantum wells ID SUPERLATTICES AB We demonstrated a 256 x 256 voltage-tunable two-color corrugated quantum-well infrared-photodetector focal plane array. The detector operation is based on photocurrent asymmetry in a double-superlattice quantum well structure. By using a broad-band corrugated light coupling scheme, we obtained a quantum efficiency of 24% in the mid-wave (MW) band and 26% in the long-wave (LW) band without AR coating. Operating at 50 K, the measured noise equivalent temperature difference is 27 mK at 33-ms integration time for the MW and 90 mK at 2 ms for the LW with 172.44 optics. The NETD operability values are 98.4% and 95.9%, respectively. C1 [Choi, Kwong-Kit] USA, Res Lab, Adelphi, MD 20783 USA. [Jhabvala, Murzy D.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Peralta, Richard J.] Raytheon Vis Syst, Goleta, CA 93105 USA. RP Choi, KK (reprint author), USA, Res Lab, Adelphi, MD 20783 USA. EM kchoi@arl.army.mil; Murzy.D.Jhabvala@nasa.gov; rjperalta@raytheon.com RI Choi, Kwong-Kit/K-9205-2013 NR 9 TC 5 Z9 5 U1 0 U2 6 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0741-3106 J9 IEEE ELECTR DEVICE L JI IEEE Electron Device Lett. PD SEP PY 2008 VL 29 IS 9 BP 1011 EP 1013 DI 10.1109/LED.2008.2001248 PG 3 WC Engineering, Electrical & Electronic SC Engineering GA 353MZ UT WOS:000259573400013 ER PT J AU Liu, Y Tang, XD Tao, G Joshi, SM AF Liu, Yu Tang, Xidong Tao, Gang Joshi, Suresh M. TI Adaptive compensation of aircraft actuation. failures using an engine differential model SO IEEE TRANSACTIONS ON CONTROL SYSTEMS TECHNOLOGY LA English DT Article DE actuator failures; adaptive compensation; aircraft control; engine differentials; tracking ID RELIABLE CONTROL; CONTROL-SYSTEM; FLIGHT CONTROL; SCHEME; DESIGN AB This paper investigates actuator failure compensation for aircraft flight control in a novel framework. A general failure compensation scheme for asymptotic tracking is developed based on a direct adaptive control approach. This control scheme is capable of utilizing the remaining control authority to achieve the desired performance in the presence of unknown and uncertain constant actuator failures occurring at unknown time instants. A nonlinear aircraft model that incorporates independently adjustable engine throttles and ailerons is employed and linearized to describe the aircraft's longitudinal and lateral motion. This model captures the key features of aircraft flight dynamics when in the engine differential mode. The proposed control scheme is applied to a transport aircraft model in the presence of three types of failures during operation: rudder failure, aileron failure, and engine malfunction. Simulation results are presented to assess the effectiveness of this adaptive failure compensation design. C1 [Liu, Yu; Tang, Xidong; Tao, Gang] Univ Virginia, Dept Elect & Comp Engn, Charlottesville, VA 22904 USA. [Joshi, Suresh M.] NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Liu, Y (reprint author), Univ Virginia, Dept Elect & Comp Engn, Charlottesville, VA 22904 USA. EM yl5c@virginia.edu; xidong.tang@gm.com; gt9s@virginia.edu; s.m.joshi@larc.nasa.gov RI Liu, Yu/A-8427-2009 FU NASA Langley Research Center [NCC-1-02006]; National Science Foundation [ECS0601475] FX This research was supported in part by NASA Langley Research Center under Grant NCC-1-02006 and by National Science Foundation under Grant ECS0601475. NR 29 TC 10 Z9 13 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 1063-6536 J9 IEEE T CONTR SYST T JI IEEE Trans. Control Syst. Technol. PD SEP PY 2008 VL 16 IS 5 BP 971 EP 982 DI 10.1109/TCST.2007.906273 PG 12 WC Automation & Control Systems; Engineering, Electrical & Electronic SC Automation & Control Systems; Engineering GA 342ZM UT WOS:000258822100011 ER PT J AU Plant, NG Holland, KT Haller, MC AF Plant, Nathaniel G. Holland, K. Todd Haller, Merrick C. TI Ocean wavenumber estimation from wave-resolving time series imagery SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article DE adaptive signal processing; image processing; sea floor; sea surface; wavelength measurement ID CURRENT RETRIEVALS; SEA-SURFACE; BATHYMETRY; DEPTH; QUANTIFICATION; DISSIPATION; DISPERSION; ZONE AB We review several approaches that have been used to estimate ocean surface gravity wavenumbers from wave-resolving remotely sensed image sequences. Two fundamentally different approaches that utilize these data exist. A power spectral density approach identifies wavenumbers where image intensity variance is maximized. Alternatively, a cross-spectral correlation approach identifies wavenumbers where intensity coherence is maximized. We develop a solution to the latter approach based on a tomographic analysis that utilizes a nonlinear inverse method. The solution is tolerant to noise and other forms of sampling deficiency and can be applied to arbitrary sampling patterns, as well as to full-frame imagery. The solution includes error predictions that can be used for data retrieval quality control and for evaluating sample designs. A quantitative analysis of the intrinsic resolution of the method indicates that the cross-spectral correlation fitting improves resolution by a factor of about ten times as compared to the power spectral density fitting approach. The resolution analysis also provides a rule of thumb for nearshore bathymetry retrievals-short-scale cross-shore patterns may be resolved if they are about ten times longer than the average water depth over the pattern. This guidance can be applied to sample design to constrain both the sensor array (image resolution) and the analysis array (tomographic resolution). C1 [Plant, Nathaniel G.] US Geol Survey, Florida Integrated Sci Ctr, St Petersburg, FL 33701 USA. [Plant, Nathaniel G.; Holland, K. Todd] USN, Res Lab, Stennis Space Ctr, Stennis Space Ctr, MS 39529 USA. [Haller, Merrick C.] Oregon State Univ, Sch Civil & Construct Engn, Corvallis, OR 97331 USA. RP Plant, NG (reprint author), US Geol Survey, Florida Integrated Sci Ctr, St Petersburg, FL 33701 USA. EM nplant@usgs.gov; tholland@nrlsse.navy.mil; hallerm@engr.orst.edu RI Holland, K. Todd/A-7673-2011; Haller, Merrick/J-8191-2012; OI Holland, K. Todd/0000-0002-4601-6097; Haller, Merrick/0000-0002-8760-4362; Plant, Nathaniel/0000-0002-5703-5672 FU Office of Naval Research [0602435N]; Army Corps of Engineers' FRF; R. Holman's Argus program FX Manuscript received January 25, 2008. This work was supported by the Office of Naval Research through the base funding program element 0602435N.; The authors would like to thank the Beach Wizards who contributed to the development of this effort. The authors are particularly indebted to P. Catalan for the encouragement, evaluation, and critical review. Comments from an anonymous reviewer considerably improved the clarity of the manuscript. Finally, we could not have performed a sensible field evaluation without the stage set by both the Army Corps of Engineers' FRF and R. Holman's Argus program. NR 33 TC 18 Z9 18 U1 0 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 SEP PY 2008 VL 46 IS 9 BP 2644 EP 2658 DI 10.1109/TGRS.2008.919821 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 348SY UT WOS:000259231600016 ER PT J AU Xie, Y Xiong, XX Qu, JJ Che, NZ Wang, LL AF Xie, Yong Xiong, Xiaoxiong Qu, John J. Che, Nianzeng Wang, Lingli TI MODIS on-orbit spatial characterization using ground targets SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article DE band-to-band registration (BBR); BBR shift; Moderate Resolution Imaging Spectroradiometer (MODIS); spatial characterization; spectroradiometric calibration assembly (SRCA) ID CALIBRATION ASSEMBLY SRCA; PERFORMANCE AB The Moderate Resolution Imaging Spectroradiometer (MODIS) sensor is currently being operated on both Terra and Aqua spacecrafts. MODIS uses 36 bands arranged in four focal plane assemblies (FPAs)-visible, near infrared, short- and middle-wavelength infrared, and long-wavelength infrared. Misregistrations between spectral bands and FPAs and changes of spatial characterization on-orbit could impact the quality of science data products generated with multiple bands located on different FPAs. In this paper, an approach is presented to compute the MODIS hand-to-hand registration (BBR) using ground measurements. A special ground scene with unique features is selected to calculate the spatial registration along-scan and along-track. The monthly and yearly spatial deviations are calculated for the bands of both Terra an Aqua MODIS except for some ocean bands, cloud bands, and the Aqua MODIS band 6. The comparison with results derived from the spectroradiometric calibration assembly, a device operated on-orbit to track the BBR shift between any two of the spectral bands, generally shows good agreement. The measured differences between these two approaches are typically less than 100 m in the scan direction and 200 m in the track direction. This approach can provide more frequent characterization of the MODIS BBR and is extremely useful for other sensors that do not have an onboard spatial characterization device. C1 [Xie, Yong; Qu, John J.; Wang, Lingli] George Mason Univ, Dept Geog & Geoinformat Sci, Coll Sci, Fairfax, VA 22030 USA. [Xiong, Xiaoxiong] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Che, Nianzeng] Sci Syst & Applicat Inc, Lanham, MD 20706 USA. RP Xie, Y (reprint author), George Mason Univ, Dept Geog & Geoinformat Sci, Coll Sci, Fairfax, VA 22030 USA. EM yxie2@gmu.edu; Xiaoxiong.Xiong.1@gsfc.nasa.gov; jqu@cos.gmu.edu; nianzeng_che@ssaihq.com; lwang2@gmu.edu FU MODIS; NASA Goddard Space Flight Center FX The authors would like to thank the MODIS Characterization Support Team of the NASA Goddard Space Flight Center for Supporting this study. NR 15 TC 5 Z9 6 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 SEP PY 2008 VL 46 IS 9 BP 2666 EP 2674 DI 10.1109/TGRS.2008.917269 PG 9 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA 348SY UT WOS:000259231600018 ER PT J AU Panov, AD Zatsepin, VI Sokolskaya, NV Adams, JH Ahn, HS Bashindzhagyan, GL Watts, JW Wefel, JP Wu, J Ganel, O Guzik, TG Gunashingha, RM Isbert, J Kim, KC Christl, M Kouznetsov, EN Panasyuk, MI Seo, ES Chang, J Schmidt, WKH Fazely, AR AF Panov, A. D. Zatsepin, V. I. Sokolskaya, N. V. Adams, J. H., Jr. Ahn, H. S. Bashindzhagyan, G. L. Watts, J. W. Wefel, J. P. Wu, J. Ganel, O. Guzik, T. G. Gunashingha, R. M. Isbert, J. Kim, K. C. Christl, M. Kouznetsov, E. N. Panasyuk, M. I. Seo, E. S. Chang, J. Schmidt, W. K. H. Fazely, A. R. TI Measuring the deposited energy by the scintillation calorimeter in the ATIC experiment SO INSTRUMENTS AND EXPERIMENTAL TECHNIQUES LA English DT Article ID CHARGE DETECTOR; SILICON MATRIX AB The purpose of the ATIC balloon experiment is to measure the energy spectra of primary cosmic rays with individual charge resolution from protons to iron over the energy range from similar to 50 GeV to 200 TeV. The particle energy is measured by a bismuth germanate (BGO) scintillation calorimeter. The procedure of calorimeter calibration is described, in particular, calibration of the temperature dependence of the calorimeter sensitivity using the data of in-flight measurements. A technique for determining the energy deposited in the calorimeter in view of the temperature dependence of its sensitivity is presented. The maximum systematic error in determining the deposited energy by the calorimeter is 10% or less, and the probable error is estimated at 6%. C1 [Panov, A. D.; Zatsepin, V. I.; Sokolskaya, N. V.; Bashindzhagyan, G. L.; Kouznetsov, E. N.; Panasyuk, M. I.] Moscow MV Lomonosov State Univ, Skobeltsyn Inst Nucl Phys, Moscow 119992, Russia. [Adams, J. H., Jr.; Watts, J. W.] NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. [Ahn, H. S.; Ganel, O.; Kim, K. C.; Christl, M.; Seo, E. S.] Univ Maryland, College Pk, MD 20742 USA. [Wefel, J. P.; Guzik, T. G.; Isbert, J.] Louisiana State Univ, Baton Rouge, LA 70803 USA. [Gunashingha, R. M.; Fazely, A. R.] So Univ, Baton Rouge, LA 70813 USA. [Chang, J.] Chinese Acad Sci, Purple Mt Observ, Nanjing 210008, Peoples R China. [Chang, J.; Schmidt, W. K. H.] Max Planck Inst Solar Syst Res, D-37191 Katlenburg Lindau, Germany. RP Panov, AD (reprint author), Moscow MV Lomonosov State Univ, Skobeltsyn Inst Nucl Phys, Moscow 119992, Russia. 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 Russian Foundation for Basic Research [05.02.16222]; National Aeronautics and Space Administration of the United States [NNG04WC12G, NNG04WC10G, NNG04WC06G] FX This work was supported by the Russian Foundation for Basic Research (grant no. 05.02.16222) and the National Aeronautics and Space Administration of the United States (grants nos. NNG04WC12G, NNG04WC10G, and NNG04WC06G). NR 14 TC 2 Z9 2 U1 0 U2 2 PU MAIK NAUKA/INTERPERIODICA/SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013-1578 USA SN 0020-4412 J9 INSTRUM EXP TECH+ JI Instrum. Exp. Tech. PD SEP PY 2008 VL 51 IS 5 BP 665 EP 681 DI 10.1134/S0020441208050047 PG 17 WC Engineering, Multidisciplinary; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 353LS UT WOS:000259570000004 ER PT J AU Przekop, A Rizzi, SA Sweitzer, KA AF Przekop, Adam Rizzi, Stephen A. Sweitzer, Karl A. TI An investigation of high-cycle fatigue models for metallic structures exhibiting snap-through response SO INTERNATIONAL JOURNAL OF FATIGUE LA English DT Article DE high-cycle thermal-acoustic fatigue; mean stress; nonlinear random response AB A study is undertaken to develop a methodology for determining the suitability of various high-cycle fatigue models for metallic structures subjected to combined thermal-acoustic loadings. Two features of this problem differentiate it from the fatigue of structures subject to acoustic loading alone. Potentially large mean stresses associated with the thermally pre- and post-buckled states require models capable of handling those conditions. Additionally, snap-through motion between multiple post-buckled equilibrium positions introduces very high alternating stress. An aluminum beam structure is chosen as the computational test article, with its geometric and material nonlinear response determined via numerical simulation. A cumulative damage model is employed using a rainflow cycle counting scheme and fatigue life estimates are made for 2024-T3 aluminum using various non-zero mean stress fatigue models, including Walker, Morrow, Morrow with true fracture strength, and MMPDS. A baseline zero-mean stress model is additionally considered. It is shown that for this material, the Walker model produces the most conservative fatigue life estimates when the stress response has a tensile mean introduced by geometric nonlinearity, but remains in the linear elastic range. However, when the loading level is sufficiently high to produce plasticity, the response becomes more fully reversed and the baseline, Morrow, and Morrow with true fracture strength models produce the most conservative fatigue life estimates. Published by Elsevier Ltd. C1 [Przekop, Adam] Natl Inst Aerosp, Hampton, VA 23666 USA. [Rizzi, Stephen A.] NASA, Langley Res Ctr, Struct Acoust Branch, Hampton, VA 23681 USA. [Sweitzer, Karl A.] ITT Corp, Div Space Syst, Rochester, NY 14606 USA. RP Przekop, A (reprint author), Natl Inst Aerosp, Hampton, VA 23666 USA. EM adam@nianet.org NR 14 TC 9 Z9 11 U1 0 U2 5 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0142-1123 J9 INT J FATIGUE JI Int. J. Fatigue PD SEP PY 2008 VL 30 IS 9 BP 1579 EP 1598 DI 10.1016/j.ijfatigue.2007.11.011 PG 20 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA 317ED UT WOS:000257001700006 ER PT J AU Gehrels, N AF Gehrels, Neil CA Swift Team TI SWIFT OBSERVATIONS OF GAMMA-RAY BURSTS SO INTERNATIONAL JOURNAL OF MODERN PHYSICS D LA English DT Article; Proceedings Paper CT International Workshop on High Energy Phenomena in Relativistic Outflows CY SEP 24-28, 2007 CL Dublin, IRELAND DE Gamma-ray bursts; gamma-ray astronomy ID 28 FEBRUARY 1997; HOST GALAXY; REDSHIFT; AFTERGLOW; GRB-050709; TELESCOPE; SUPERNOVA; EMISSION; POPULATION; GRB-060614 AB The Swift mission, launched on 20 November 2004, is detecting similar to 100 gamma-ray bursts (GRBs) each year, and immediately (within similar to 90 s) starting X-ray and UV/optical observations of the afterglow. It has already collected an impressive database including prompt emission to higher sensitivities than BATSE, uniform monitoring of afterglows, and rapid follow-up by other observatories notified through the Gamma-ray bursts Coordinates Network (GCN). The X-ray afterglows have been found to have complex temporal shapes including tails emission from the prompt phase and bright flares. X-ray and optical afterglow detections from short bursts have led to accurate localizations. It is found that they can occur in non-star forming galaxies or regions, whereas long GRBs are strongly concentrated within star forming regions. This is consistent with the NS merger model. Swift has greatly increased the redshift range of GRB detection. The highest redshift GRBs, at z similar to 5-6, are approaching the era of reionization. Ground-based deep optical spectroscopy of high redshift bursts is giving metallicity measurements and other information on the source environment to much greater distance than other techniques. The localization of GRB 060218 in a nearby galaxy, and association with SN 2006aj, added a valuable member to the class of GRBs with detected supernova. The prospects for future progress are excellent given the > 10 year orbital lifetime of the Swift satellite. C1 [Gehrels, Neil; Swift Team] NASA, Goddard Space Flight Ctr, Astroparticle Phys Lab, Greenbelt, MD 20771 USA. RP Gehrels, N (reprint author), NASA, Goddard Space Flight Ctr, Astroparticle Phys Lab, Greenbelt, MD 20771 USA. RI Gehrels, Neil/D-2971-2012 NR 40 TC 0 Z9 0 U1 0 U2 1 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA 5 TOH TUCK LINK, SINGAPORE 596224, SINGAPORE SN 0218-2718 J9 INT J MOD PHYS D JI Int. J. Mod. Phys. D PD SEP PY 2008 VL 17 IS 9 BP 1311 EP 1317 DI 10.1142/S0218271808012863 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 371AB UT WOS:000260803100002 ER PT J AU Maraschi, L Ghisellini, G Tavecchio, F Foschini, L Sambruna, RM AF Maraschi, L. Ghisellini, G. Tavecchio, F. Foschini, L. Sambruna, R. M. TI THE SPECTRAL SEQUENCE OF BLAZARS - STATUS AND PERSPECTIVES SO INTERNATIONAL JOURNAL OF MODERN PHYSICS D LA English DT Article; Proceedings Paper CT International Workshop on High Energy Phenomena in Relativistic Outflows CY SEP 24-28, 2007 CL Dublin, IRELAND DE Blazars; BL Lac objects; flat-spectrum radio quasars; relativistic jets; gamma-ray observations ID RADIO-LOUD QUASARS; JET-DISK CONNECTION; RAY; LINE; UNIFICATION; EMISSION; GALAXIES; OBJECTS; CHANDRA; VIEW AB The present status of the blazar spectral sequence is discussed, including new findings about blazars selected with different criteria than the original complete radio-samples. Despite extensive searches of blazars "breaking" the sequence, the original idea proposed 10 years ago still seems to hold. On the other hand, the forthcoming launch of the GLAST satellite will provide a new selection band for blazars and blazar related populations as well as fantastic progress on the spectra and variability behaviour of presently known blazars. The order of magnitude increase in sensitivity of GLAST will allow detection of gamma-rays from jets with lower power and/or lower beaming factor, thus sampling a much wider population. C1 [Maraschi, L.; Ghisellini, G.; Tavecchio, F.] INAF Osservatorio Astron Merate, I-20121 Milan, Italy. [Foschini, L.] INAF IASF Bologna, I-40129 Bologna, Italy. [Sambruna, R. M.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Maraschi, L (reprint author), INAF Osservatorio Astron Merate, Via Brera 28, I-20121 Milan, Italy. EM laura.maraschi@brera.inaf.it RI Foschini, Luigi/H-3833-2012 OI Foschini, Luigi/0000-0001-8678-0324 NR 27 TC 2 Z9 2 U1 0 U2 3 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA 5 TOH TUCK LINK, SINGAPORE 596224, SINGAPORE SN 0218-2718 J9 INT J MOD PHYS D JI Int. J. Mod. Phys. D PD SEP PY 2008 VL 17 IS 9 BP 1457 EP 1466 DI 10.1142/S0218271808013030 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 371AB UT WOS:000260803100019 ER PT J AU Sambruna, RM Maraschi, L Tavecchio, F AF Sambruna, R. M. Maraschi, L. Tavecchio, F. TI TOWARDS A UNITARIAN VIEW OF CHANDRA JETS SO INTERNATIONAL JOURNAL OF MODERN PHYSICS D LA English DT Article; Proceedings Paper CT International Workshop on High Energy Phenomena in Relativistic Outflows CY SEP 24-28, 2007 CL Dublin, IRELAND DE X-rays; Chandra; jets ID X-RAY JET; HUBBLE-SPACE-TELESCOPE; EXTENDED RADIO JETS; RELATIVISTIC JETS; DEEP CHANDRA; CONNECTION; BLAZARS; 3C-273 AB In almost a decade of operations, Chandra has observed and discovered the X-ray counterparts of several tens of extragalactic radio jets, with a variety of morphologies and SEDs. Here we take a fresh approach and assume that we do not know their relationship. We then search for phenomenological trends. While admittedly naive, this perspective allow us to start identifying key quantities towards a large-scale jet "unitarian view", just as was previously done for their compact, pc-scale cousins, the blazars. Similarly to the latter, we find that key parameters governing the properties of Chandra jets are their powers and the mass flux, the latter parameterizing the jet interaction with the ambient gas. C1 [Sambruna, R. M.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Maraschi, L.; Tavecchio, F.] Osserv Astron Brera, I-20121 Milan, Italy. RP Sambruna, RM (reprint author), NASA, Goddard Space Flight Ctr, Code 661, Greenbelt, MD 20771 USA. EM Rita.M.Sambruna@nasa.gov; laura.maraschi@inaf.brera.it; fabrizio.tavecchio@inaf.brera.it NR 21 TC 0 Z9 0 U1 0 U2 1 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA 5 TOH TUCK LINK, SINGAPORE 596224, SINGAPORE SN 0218-2718 J9 INT J MOD PHYS D JI Int. J. Mod. Phys. D PD SEP PY 2008 VL 17 IS 9 BP 1467 EP 1474 DI 10.1142/S0218271808013042 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 371AB UT WOS:000260803100020 ER PT J AU Mastichiadis, A Kazanas, D AF Mastichiadis, A. Kazanas, D. TI THE SUPERCRITICAL PILE MODEL FOR GRBs: THE PROMPT TO EARLY AFTERGLOW STAGE SO INTERNATIONAL JOURNAL OF MODERN PHYSICS D LA English DT Article; Proceedings Paper CT International Workshop on High Energy Phenomena in Relativistic Outflows CY SEP 24-28, 2007 CL Dublin, IRELAND DE Gamma-ray bursts; relativistic plasmas ID GAMMA-RAY BURSTS; 28 FEBRUARY 1997; EMISSION; BATSE AB The "supercritical pile" is a very economical GRB model that provides for the efficient conversion of the energy stored in the protons of a relativistic blast wave (RBW) into radiation and at the same time produces - in the prompt GRB phase, even in the absence of any particle acceleration - a spectral peak at an energy similar to 1 MeV. We extend this model to include also the evolution of the RBW Lorentz factor Gamma and thus follow the spectral and temporal features of this model into the GRB early afterglow stage. One of the novel features of the present treatment is the inclusion of the feedback of the GRB produced radiation on the evolution of Gamma with radius. This way one can obtain afterglow light curves with steep decays followed by a relatively flatter flux stage, as observed in a large number of bursts. C1 [Mastichiadis, A.] Univ Athens, Dept Phys, GR-15783 Zografos, Greece. [Kazanas, D.] NASA, Goddard Space Flight Ctr, Astrophys Sci Div, Greenbelt, MD 20771 USA. RP Mastichiadis, A (reprint author), Univ Athens, Dept Phys, GR-15783 Zografos, Greece. EM amastich@phys.uoa.gr NR 15 TC 0 Z9 0 U1 0 U2 1 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA 5 TOH TUCK LINK, SINGAPORE 596224, SINGAPORE SN 0218-2718 EI 1793-6594 J9 INT J MOD PHYS D JI Int. J. Mod. Phys. D PD SEP PY 2008 VL 17 IS 9 BP 1641 EP 1650 DI 10.1142/S021827180801325X PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 371AB UT WOS:000260803100041 ER PT J AU Dorodnitsyn, AV AF Dorodnitsyn, A. V. TI GRAVITATIONALLY DISTORTED P-CYGNI PROFILES FROM OUTFLOWS NEAR COMPACT OBJECTS SO INTERNATIONAL JOURNAL OF MODERN PHYSICS D LA English DT Article; Proceedings Paper CT International Workshop on High Energy Phenomena in Relativistic Outflows CY SEP 24-28, 2007 CL Dublin, IRELAND DE Line formation; radiative transfer; active galaxies; radiation mechanisms; stellar winds ID LINE-DRIVEN WINDS; REDSHIFTED ABSORPTION AB Spectral line profiles produced in an outflow near a neutron star or a black hole can be strongly influenced by gravitational redshifting and by Doppler shifting due to a global motion of plasma. We consider a scenario in which a resonant absorption in a spectral line takes place in the outflowing plasma within several tens of Schwarzschild radii from a compact object. The main goal of this work is to show that under certain conditions a combination of the gravitational redshifting and Doppler blue/redshifting may produce line profiles which can be considered as "fingerprints" of the gravitational field of the compact object, much as P-Cygni profiles are "fingerprints" of stellar winds. C1 [Dorodnitsyn, A. V.] NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. [Dorodnitsyn, A. V.] Space Res Inst, Moscow 117997, Russia. RP Dorodnitsyn, AV (reprint author), NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. EM dora@milkyway.gsfc.nasa.gov NR 10 TC 0 Z9 0 U1 0 U2 1 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA 5 TOH TUCK LINK, SINGAPORE 596224, SINGAPORE SN 0218-2718 J9 INT J MOD PHYS D JI Int. J. Mod. Phys. D PD SEP PY 2008 VL 17 IS 10 BP 1743 EP 1749 DI 10.1142/S0218271808013364 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 376EX UT WOS:000261167900010 ER PT J AU Nishikawa, KI Mizuno, Y Fishman, GJ Hardee, P AF Nishikawa, K. -I. Mizuno, Y. Fishman, G. J. Hardee, P. TI PARTICLE ACCELERATION, MAGNETIC FIELD GENERATION, AND ASSOCIATED EMISSION IN COLLISIONLESS RELATIVISTIC JETS SO INTERNATIONAL JOURNAL OF MODERN PHYSICS D LA English DT Article; Proceedings Paper CT International Workshop on High Energy Phenomena in Relativistic Outflows CY SEP 24-28, 2007 CL Dublin, IRELAND DE Filamentation instability; magnetic field generation; particle acceleration; jitter radiation ID GAMMA-RAY BURSTS; PROMPT EMISSION; AFTERGLOW EMISSION; JITTER RADIATION; SHOCKS; PRECURSORS; FIREBALLS AB Nonthermal radiation observed from astrophysical systems containing relativistic jets and shocks, e. g., active galactic nuclei (AGNs), gamma-ray bursts (GRBs), and galactic microquasar systems usually have power-law emission spectra. Recent PIC simulations using injected relativistic electron-ion (electron-positron) jets show that acceleration occurs within the downstream jet. Shock acceleration is an ubiquitous phenomenon in astrophysical plasmas. Plasma waves and their associated instabilities (e. g., the Buneman instability, other two-streaming instability, and the Weibel instability) created in the shocks are responsible for particle (electron, positron, and ion) acceleration. The simulation results show that the Weibel instability is responsible for generating and amplifying highly nonuniform, small-scale magnetic fields. These magnetic fields contribute to the electrons' transverse deflection behind the jet head. The "jitter" radiation from deflected electrons has different properties to synchrotron radiation which assumes a uniform magnetic field. This jitter radiation may be important to understanding the complex time evolution and/or spectral structure in gamma-ray bursts, relativistic jets, and supernova remnants. C1 [Nishikawa, K. -I.] NSSTC, Gamma Ray Astrophys, Huntsville, AL 35805 USA. [Mizuno, Y.; Fishman, G. J.] NASA, MSFC, Huntsville, AL 35805 USA. [Hardee, P.] Univ Alabama, Dept Phys & Astron, Tuscaloosa, AL 35487 USA. RP Nishikawa, KI (reprint author), NSSTC, Gamma Ray Astrophys, 320 Sparkman Dr, Huntsville, AL 35805 USA. EM ken-ichi.nishikawa-1@nasa.gov RI Mizuno, Yosuke/D-5656-2017 OI Mizuno, Yosuke/0000-0002-8131-6730 NR 21 TC 6 Z9 6 U1 0 U2 1 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA 5 TOH TUCK LINK, SINGAPORE 596224, SINGAPORE SN 0218-2718 J9 INT J MOD PHYS D JI Int. J. Mod. Phys. D PD SEP PY 2008 VL 17 IS 10 BP 1761 EP 1767 DI 10.1142/S0218271808013388 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 376EX UT WOS:000261167900012 ER PT J AU Hong, Y Adler, RF AF Hong, Yang Adler, Robert F. TI Predicting global landslide spatiotemporal distribution: Integrating landslide susceptibility zoning techniques and real-time satellite rainfall estimates SO INTERNATIONAL JOURNAL OF SEDIMENT RESEARCH LA English DT Article DE Landslide; Natural disasters; Satellite remote sensing; Real-time precipitation analysis; Landslide susceptibility ID PUERTO-RICO; INTENSITY; GIS AB Landslides triggered by rainfall can possibly be foreseen in real time by jointly using rainfall intensity-duration thresholds and information related to land surface susceptibility. However, no system exists at either a national or a global scale to monitor or detect rainfall conditions that may trigger landslides due to the lack of sufficient ground-based observing network in many parts of the world. Recent advances in satellite remote sensing technology and increasing availability of high-resolution geospatial products around the globe have provided an unprecedented opportunity for such a study. In this paper, a framework for developing a preliminary real-time prediction system to identify where rainfall-triggered landslides will occur is proposed by combining two necessary components: surface landslide susceptibility and a real-time space-based rainfall analysis system (http://trmm.gsfc.nasa.gov). First, a global landslide susceptibility map is derived from a combination of semi-static global surface characteristics (digital elevation topography, slope, soil types, soil texture, land cover classification, etc.) using a GIS weighted linear combination approach. Second, an adjusted empirical relationship between rainfall intensity-duration and landslide occurrence is used to assess landslide hazards at areas with high susceptibility. A major outcome of this work is the availability for the first time of a global assessment of landslide hazards, which is only possible because of the utilization of global satellite remote sensing products. This preliminary system can be updated continuously using the new satellite remote sensing products. This proposed system, if pursued through wide interdisciplinary efforts as recommended herein, bears the promise to grow many local landslide hazard analyses into a global decision-making support system for landslide disaster preparedness and mitigation activities across the world, C1 [Hong, Yang; Adler, Robert F.] NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. [Hong, Yang] Univ Oklahoma, Sch Civil Engn & Environm Sci, Norman, OK 73019 USA. RP Hong, Y (reprint author), NASA, Goddard Space Flight Ctr, Atmospheres Lab, Code 613-1, Greenbelt, MD 20771 USA. EM yanghong@ou.edu RI Hong, Yang/D-5132-2009 OI Hong, Yang/0000-0001-8720-242X FU NASA's Applied Sciences; University of Oklahoma FX This research is carried out with support from NASA's Applied Sciences program under Steven Anbrose of NASA Headquarters and with support from University of Oklahoma. NR 25 TC 15 Z9 22 U1 1 U2 29 PU IRTCES PI BEIJING PA PO BOX 366, BEIJING, 100044, PEOPLES R CHINA SN 1001-6279 J9 INT J SEDIMENT RES JI Int. J. Sediment Res. PD SEP PY 2008 VL 23 IS 3 BP 249 EP 257 DI 10.1016/S1001-6279(08)60022-0 PG 9 WC Environmental Sciences; Water Resources SC Environmental Sciences & Ecology; Water Resources GA 367JF UT WOS:000260547600005 ER PT J AU Arakere, NK Knudsen, EC Wells, D McGill, P Swanson, GR AF Arakere, Nagaraj K. Knudsen, Erik C. Wells, Doug McGill, Preston Swanson, Gregory R. TI Determination of mixed-mode stress intensity factors, fracture toughness, and crack turning angle for anisotropic foam material SO INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES LA English DT Article DE foam; anisotropy; stress intensity factor; mixed-mode loading; fracture toughness; crack turning angle; anisotropic toughness ID ENERGY-RELEASE RATES; EXTENSION; SOLIDS; PLANE; BODY AB A numerical and experimental investigation for determining mixed-mode stress intensity factors, fracture toughness, and crack turning angle for BX-265 foam insulation material, used by NASA to insulate the external tank (ET) for the space shuttle, is presented. BX-265 foam is a type of spray-on foam insulation (SOFI), similar to the material used to insulate attics in residential construction. This cellular material is a good insulator and is very lightweight. Breakup of segments of this foam insulation on the shuttle ET impacting the shuttle thermal protection tiles during liftoff is believed to have caused the space shuttle Columbia failure during re-entry. NASA engineers are interested in understanding the processes that govern the breakup/fracture of this material from the shuttle ET. The foam is anisotropic in nature and the required stress and fracture mechanics analysis must include the effects of the direction dependence on material properties. Material testing at NASA Marshall Space Flight Center (MSFC) has indicated that the foam can be modeled as a transversely isotropic material. As a first step toward understanding the fracture mechanics of this material, we present a general theoretical and numerical framework for computing stress intensity factors (SIFs), under mixed-mode loading conditions, taking into account the material anisotropy. We present SIFs for middle tension - M(T) - test specimens. using 3D finite element stress analysis (ANSYS) and FRANC3D fracture analysis software. SIF values are presented for a range of foam material orientations. Mode I fracture toughness of the material is determined based on the SIF value at failure load. We also present crack turning angles for anisotropic foam material under mixed-mode loading. The results represent a quantitative basis for evaluating the strength and fracture properties of anisotropic foam insulation material, (C) 2008 Elsevier Ltd. All rights reserved. C1 [Arakere, Nagaraj K.; Knudsen, Erik C.] Univ Florida, Dept Mech & Aerosp Engn, Gainesville, FL 32611 USA. [Knudsen, Erik C.; Wells, Doug; McGill, Preston; Swanson, Gregory R.] NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Arakere, NK (reprint author), Univ Florida, Dept Mech & Aerosp Engn, 237 MAE-B, Gainesville, FL 32611 USA. EM nagaraj@ufl.edu FU NASA Marshall Space Flight Center; Cornell University Fracture Group FX This work was Supported by the NASA Marshall Space Flight Center, Huntsville, AL. Discussions on theoretical aspects and finite element modeling of cracks in anisotropic materials with Drs. B. Carter and P. Wawrzynek of the Cornell University Fracture Group, and Dr. R. Pettit at Pratt & Whitney, East Hartford, CT, has contributed greatly towards our understanding and completion of this work. NR 34 TC 7 Z9 7 U1 0 U2 14 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0020-7683 J9 INT J SOLIDS STRUCT JI Int. J. Solids Struct. PD SEP PY 2008 VL 45 IS 18-19 BP 4936 EP 4951 DI 10.1016/j.ijsolstr.2008.04.028 PG 16 WC Mechanics SC Mechanics GA 339AI UT WOS:000258550100004 ER PT J AU Kukreja, SL AF Kukreja, Sunil L. TI Structure Computation, of Quiet Spike(TM) Flight-Test Elata During Envelope Expansion SO JOURNAL OF AIRCRAFT LA English DT Article ID NON-LINEAR SYSTEMS; OUTPUT PARAMETRIC MODELS; BOOTSTRAP METHOD; NARMAX MODELS; IDENTIFICATION; TUTORIAL AB System identification or mathematical modeling is used in the aerospace community for development of simulation models for robust control law design. These models are often described as linear time-invariant processes. Nevertheless, it is well known that the underlying process is often nonlinear. The reason for using a linear approach has been due to the lack of a proper set of tools for the identification of nonlinear systems. Over the past several decades, the controls and biomedical communities have made great advances in developing tools for the identification of nonlinear systems. These approaches are robust and readily applicable to aerospace systems. In this paper, we show the application of one such nonlinear system identification technique, structure detection, for the analysis of F-15B Quiet Spike(TM) aeroservoelastic flight-test data. Structure detection is concerned with the selection of a subset of candidate terms that best describe the observed output. This is a necessary procedure to compute an efficient system description that may afford greater insight into the functionality of the system or a simpler controller design. Structure computation as a tool for black-box modeling may be of critical importance for the development of robust parsimonious models for the flight-test community. Moreover, this approach may lead to efficient strategies for rapid envelope expansion, which may save significant development time and costs. The objectives of this study are to demonstrate via analysis of F-15B Quiet Spike aeroservoelastic flight-test data for several flight conditions that 1) linear models are inefficient for modeling aeroservoelastic data, 2) nonlinear identification provides a parsimonious model description while providing a high percent fit for cross-validated data, and 3) the model structure and parameters vary as the flight condition is altered. C1 NASA, Dryden Flight Res Ctr, Aerostruct Branch, Struct Dynam Grp, Edwards AFB, CA 93523 USA. RP Kukreja, SL (reprint author), NASA, Dryden Flight Res Ctr, Aerostruct Branch, Struct Dynam Grp, Mail Stop 4820 2A, Edwards AFB, CA 93523 USA. EM Sunil.L.Kukreja@nasa.gov NR 34 TC 0 Z9 0 U1 0 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 SEP-OCT PY 2008 VL 45 IS 5 BP 1579 EP 1584 DI 10.2514/1.32799 PG 6 WC Engineering, Aerospace SC Engineering GA 360RF UT WOS:000260074500012 ER PT J AU Ho, JC Yeo, H Ormiston, RA AF Ho, Jimmy C. Yeo, Hyeonsoo Ormiston, Robert A. TI Investigation of Rotor Blade Structural Dynamics and Modeling Based on Measured Airloads SO JOURNAL OF AIRCRAFT LA English DT Article ID HELICOPTER AB The work presented herein treats measured airloads from the UH-60A Airloads Program as prescribed external loads to calculate the resulting structural loads and motions of a rotor blade. Without the need to perform any aerodynamic computations, the coupled aeroelastic response problem is reduced to one involving only structural dynamics. The results, computed by RCAS and CAMRAD II, are compared against measured results and against each other for three representative test points. The results from the two codes mostly validate each other. Seven more test points, with responses computed by RCAS, to form thrust and airspeed sweeps are evaluated to better understand key issues. One such issue is an inability to consistently predict pushrod loads and torsion moments well, and this is found to be amplified at the two test points with the highest thrust coefficient. For these two test points, harmonic analysis reveals that the issue is due to excessive amounts of 5/rev response that stem from high levels of 5/rev pitching moment excitation. Another issue that concerns all test points is that the phase of the 1/rev blade flapping motion is not predicted well, which reflects the high sensitivity of this quantity that is developed due to having a first flap frequency of approximately 1/rev. Results also show that current force-velocity relationships, used in describing the lead-lag damper, are not satisfactory to consistently yield accurate inboard chordwise bending moment predictions. Overall, the investigation here, conducted with numerous test points, further confirms the methodology of prescribing measured airloads for assessing the structural dynamics capability of a computational tool. C1 [Ho, Jimmy C.] Georgia Inst Technol, Guggenheim Sch Aerosp Engn, Atlanta, GA 30332 USA. [Ho, Jimmy C.; Yeo, Hyeonsoo; Ormiston, Robert A.] USA, Res Dev & Engn Command, Aeroflightdynam Directorate AMRDEC, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Ho, JC (reprint author), Georgia Inst Technol, Guggenheim Sch Aerosp Engn, 270 Ferst Dr, Atlanta, GA 30332 USA. EM JHo@gatech.edu NR 16 TC 13 Z9 13 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 SEP-OCT PY 2008 VL 45 IS 5 BP 1631 EP 1642 DI 10.2514/1.34025 PG 12 WC Engineering, Aerospace SC Engineering GA 360RF UT WOS:000260074500017 ER PT J AU Bosilovich, MG Chen, JY Robertson, FR Adler, RF AF Bosilovich, Michael G. Chen, Junye Robertson, Franklin R. Adler, Robert F. TI Evaluation of global precipitation in reanalyses SO JOURNAL OF APPLIED METEOROLOGY AND CLIMATOLOGY LA English DT Article ID 20TH-CENTURY CLIMATE VARIATIONS; NCEP-NCAR; ECMWF REANALYSIS; SPATIOTEMPORAL STRUCTURE; ANTARCTIC PRECIPITATION; HYDROLOGICAL CYCLE; ENERGY BUDGETS; SURFACE-WATER; UNITED-STATES; PART I AB Retrospective-analysis (or reanalysis) systems merge observations and models to provide global four-dimensional earth system data encompassing many physical and dynamical processes. Precipitation is one critical diagnostic that is not only sensitive to the observing system and model physics, but also reflects the general circulation. Climate records of observed precipitation through a merged satellite and gauge dataset provide a reference for comparison, though not without their own uncertainty. In this study, five reanalyses precipitation fields are compared with two observed data products to assess the strengths and weaknesses of the reanalyses. Taylor diagrams show the skill of the reanalyses relative to the reference dataset. While there is a general sense that the reanalyses precipitation data are improving in recent systems, it is not always the case. In some ocean regions, NCEP-NCAR reanalysis spatial patterns are closer to observed precipitation than NCEP-Department of Energy. The 40-yr ECMWF reanalysis (ERA-40) produces reasonable comparisons over Northern Hemisphere continents, but less so in the tropical oceans. On the other hand, the most recent reanalysis, the Japanese 25-yr reanalysis (JRA-25), shows good comparisons in both the Northern Hemisphere continents and the tropical oceans but contains distinct variation according to the available observing systems. The statistics and methods used are also tested on short experiments from a data assimilation system proposed to perform a satellite-era reanalysis. C1 [Bosilovich, Michael G.; Chen, Junye] NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Chen, Junye; Adler, Robert F.] Univ Maryland, Earth Syst Sci Interdisciplinary Ctr, College Pk, MD 20742 USA. [Robertson, Franklin R.] NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Bosilovich, MG (reprint author), NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Goddard Space Flight Ctr, Code 610-1, Greenbelt, MD 20771 USA. EM michael.bosilovich@nasa.gov RI Chen, Junye/G-4301-2011; Bosilovich, Michael/F-8175-2012 NR 49 TC 143 Z9 149 U1 3 U2 31 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 SEP PY 2008 VL 47 IS 9 BP 2279 EP 2299 DI 10.1175/2008JAMC1921.1 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 349XU UT WOS:000259317400002 ER PT J AU Yang, P Zhang, ZB Kattawar, GW Warren, SG Baum, BA Huang, HL Hu, YX Winker, D Iaquinta, J AF Yang, Ping Zhang, Zhibo Kattawar, George W. Warren, Stephen G. Baum, Bryan A. Huang, Hung-Lung Hu, Yong X. Winker, David Iaquinta, Jean TI Effect of cavities on the optical properties of bullet rosettes: Implications for active and passive remote sensing of ice cloud properties SO JOURNAL OF APPLIED METEOROLOGY AND CLIMATOLOGY LA English DT Article ID SINGLE-SCATTERING PROPERTIES; INHOMOGENEOUS HEXAGONAL MONOCRYSTALS; POLARIZED-LIGHT SCATTERING; ADEOS-POLDER MEASUREMENTS; CIRRUS CLOUDS; RADIATIVE PROPERTIES; SOLAR-RADIATION; T-MATRIX; NONSPHERICAL PARTICLES; INFRARED RADIANCES AB Bullet rosette particles are common in ice clouds, and the bullets may often be hollow. Here the single-scattering properties of randomly oriented hollow bullet rosette ice particles are investigated. A bullet, which is an individual branch of a rosette, is defined as a hexagonal column attached to a hexagonal pyramidal tip. For this study, a hollow structure is included at the end of the columnar part of each bullet branch and the shape of the hollow structure is defined as a hexagonal pyramid. A hollow bullet rosette may have between 2 and 12 branches. An improved geometric optics method is used to solve for the scattering of light in the particle. The primary optical effect of incorporating a hollow end in each of the bullets is to decrease the magnitude of backscattering. In terms of the angular distribution of scattered energy, the hollow bullets increase the scattering phase function values within the forward scattering angle region from 1 degrees to 20 degrees but decrease the phase function values at side- and backscattering angles of 60 degrees-180 degrees. As a result, the presence of hollow bullets tends to increase the asymmetry factor. In addition to the scattering phase function, the other elements of the phase matrix are also discussed. The backscattering depolarization ratios for hollow and solid bullet rosettes are found to be very different. This may have an implication for active remote sensing of ice clouds, such as from polarimetric lidar measurements. In a comparison of solid and hollow bullet rosettes, the effect of the differences on the retrieval of both the ice cloud effective particle size and optical thickness is also discussed. It is found that the presence of hollow bullet rosettes acts to decrease the inferred effective particle size and to increase the optical thickness in comparison with the use of solid bullet rosettes. C1 [Yang, Ping; Zhang, Zhibo] Texas A&M Univ, Dept Atmospher Sci, College Stn, TX 77843 USA. [Kattawar, George W.] Texas A&M Univ, Dept Phys, College Stn, TX 77843 USA. [Warren, Stephen G.] Univ Washington, Dept Atmospher Sci, Seattle, WA 98195 USA. [Baum, Bryan A.; Huang, Hung-Lung] Univ Wisconsin, Ctr Space Sci & Engn, Madison, WI USA. [Hu, Yong X.; Winker, David] NASA, Langley Res Ctr, Hampton, VA 23665 USA. [Iaquinta, Jean] Transport Res Lab, Wokingham, Berks, England. RP Yang, P (reprint author), Texas A&M Univ, Dept Atmospher Sci, TAMU 3150, College Stn, TX 77843 USA. EM pyang@ariel.met.tamu.edu RI Zhang, Zhibo/D-1710-2010; Yang, Ping/B-4590-2011; Baum, Bryan/B-7670-2011; Hu, Yongxiang/K-4426-2012 OI Zhang, Zhibo/0000-0001-9491-1654; Baum, Bryan/0000-0002-7193-2767; FU National Science Foundation Physical Meteorology Program [ATM-0239605]; National Aeronautics and Space Administration (NASA) [NNL06AA23G]; Office of Naval Research [N00014-02-1-0478, N00014-06-1-0069] FX Ping Yang's research is supported by the National Science Foundation Physical Meteorology Program (ATM-0239605), and a research grant (NNL06AA23G) from the National Aeronautics and Space Administration (NASA). George Kattawar's research is supported by the Office of Naval Research under Contracts N00014-02-1-0478 and N00014-06-10069. NR 72 TC 23 Z9 23 U1 1 U2 4 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 SEP PY 2008 VL 47 IS 9 BP 2311 EP 2330 DI 10.1175/2008JAMC1905.1 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 349XU UT WOS:000259317400004 ER PT J AU Muratov, CB Osipov, VV AF Muratov, C. B. Osipov, V. V. TI Theory of 360 degrees domain walls in thin ferromagnetic films SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID ULTRATHIN COBALT FILMS; PERMALLOY-FILMS; MAGNETIC MULTILAYER; NEEL WALLS; GIANT MAGNETORESISTANCE; EFFECTIVE DYNAMICS; EXCHANGE; EXCITATION; REVERSAL; JUNCTION AB An analytical and computational study of 360 degrees domain walls in thin uniaxial ferromagnetic films is presented. The existence of stable one-dimensional 360 degrees domain wall solutions both with and without the applied field is demonstrated in a reduced thin film micromagnetic model. The wall energy is found to depend rather strongly on the orientation of the wall and the wall width significantly grows when the strength of the magnetostatic forces increases. It is also shown that a critical reverse field is required to break up a 360 degrees domain wall into a pair of 180 degrees walls. The stability of the 360 degrees walls in two-dimensional films of finite extent is demonstrated numerically and the stability with respect to slow modulations in extended films is demonstrated analytically. These domain wall solutions are shown to play an important role in magnetization reversal. In particular, it is found that the presence of 360 degrees domain walls may result in nonuniqueness of the observed magnetization patterns during repeated cycles of magnetization reversal by pulsed fields. (C) 2008 American Institute of Physics. C1 [Muratov, C. B.] New Jersey Inst Technol, Dept Math Sci, Newark, NJ 07102 USA. [Osipov, V. V.] Mission Crit Technol Inc, El Segundo, CA 90245 USA. [Osipov, V. V.] NASA, Ames Res Ctr, D&SH Branch, Intelligent Syst Div, Moffett Field, CA 94035 USA. RP Muratov, CB (reprint author), New Jersey Inst Technol, Dept Math Sci, Newark, NJ 07102 USA. EM muratov@njit.edu FU NSF [DMS-0718027] FX One of us (C.B.M.) would like to acknowledge fruitful discussions with A. Capella, H. Knupfer, R. V. Kohn, C. Melcher, and M. Novaga. The work of C.B.M. was supported in part by NSF via Grant No. DMS-0718027. NR 58 TC 28 Z9 28 U1 1 U2 18 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-8979 EI 1089-7550 J9 J APPL PHYS JI J. Appl. Phys. PD SEP 1 PY 2008 VL 104 IS 5 AR 053908 DI 10.1063/1.2970100 PG 14 WC Physics, Applied SC Physics GA 357NO UT WOS:000259853600084 ER PT J AU Tesch, PA von Walden, F Gustafsson, T Linnehan, RM Trappe, TA AF Tesch, Per A. von Walden, Ferdinand Gustafsson, Thomas Linnehan, Richard M. Trappe, Todd A. TI Skeletal muscle proteolysis in response to short-term unloading in humans SO JOURNAL OF APPLIED PHYSIOLOGY LA English DT Article DE contractile protein breakdown; microdialysis; muscle atrophy; spaceflight simulation; 3-methylhistidine ID SHORT-DURATION SPACEFLIGHT; BED-REST; RESISTANCE EXERCISE; NUTRITION COUNTERMEASURES; PROTEIN BREAKDOWN; FIBER FUNCTION; 3-METHYLHISTIDINE EXCRETION; CONCURRENT EXERCISE; KNEE EXTENSOR; SOLEUS MUSCLE AB Skeletal muscle atrophy is evident after muscle disuse, unloading, or spaceflight and results from decreased protein content as a consequence of decreased protein synthesis, increased protein breakdown or both. At this time, there are essentially no human data describing proteolysis in skeletal muscle undergoing atrophy on Earth or in space, primarily due to lack of valid and accurate methodology. This particular study aimed at assessing the effects of short-term unloading on the muscle contractile proteolysis rate. Eight men were subjected to 72-h unilateral lower limb suspension (ULLS) and intramuscular interstitial levels of the naturally occurring proteolytic tracer 3-methylhistidine (3MH) were measured by means of microdialysis before and on completion of this intervention. The 3MH concentration following 72-h ULLS (2.01 +/- 0.22 nmol/ml) was 44% higher (P < 0.05) than before ULLS (1.56 +/- 0.20 nmol/ml). The present experimental model and the employed method determining 3MH in microdialysates present a promising tool for monitoring skeletal muscle proteolysis or metabolism of specific muscles during conditions resulting in atrophy caused by, e. g., disuse and real or simulated microgravity. This study provides evidence that the atrophic processes are evoked rapidly and within 72 h of unloading and suggests that countermeasures should be employed in the early stages of space missions to offset or prevent muscle loss during the period when the rate of muscle atrophy is the highest. C1 [Tesch, Per A.] Mid Sweden Univ, Dept Hlth Sci, SE-83125 Ostersund, Sweden. [Tesch, Per A.; von Walden, Ferdinand] Karolinska Inst, Dept Physiol & Pharmacol, Stockholm, Sweden. [Gustafsson, Thomas] Karolinska Inst, Dept Lab Med, Stockholm, Sweden. [Trappe, Todd A.] Ball State Univ, Human Performance Lab, Muncie, IN 47306 USA. [Linnehan, Richard M.] Johnson Space Ctr, Natl Aeronaut & Space Adm, Astronaut Off, Houston, TX USA. RP Tesch, PA (reprint author), Mid Sweden Univ, Dept Hlth Sci, SE-83125 Ostersund, Sweden. EM Per.Tesch@miun.se OI Gustafsson, Thomas/0000-0002-1559-4206 FU National Aeronautics and Space Administration; Swedish Council of Sports; Centre of Gender Medicine; Swedish National Space Board; Loo and Hans Osterman Foundation; National Institute on Aging [AG-020532] FX This investigation was supported by a grant from the National Aeronautics and Space Administration (to R. M. Linnehan). Partial funding was provided by the Swedish Council of Sports (to P. A. Tesch and T. Gustafsson), the Centre of Gender Medicine (to P. A. Tesch), the Swedish National Space Board (to P. A. Tesch), the Loo and Hans Osterman Foundation (to T. Gustafsson), and National Institute on Aging Grant AG-020532 (to T. A. Trappe). NR 45 TC 65 Z9 70 U1 3 U2 20 PU AMER PHYSIOLOGICAL SOC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 USA SN 8750-7587 J9 J APPL PHYSIOL JI J. Appl. Physiol. PD SEP PY 2008 VL 105 IS 3 BP 902 EP 906 DI 10.1152/japplphysiol.90558.2008 PG 5 WC Physiology; Sport Sciences SC Physiology; Sport Sciences GA 345ZT UT WOS:000259038900018 PM 18535133 ER PT J AU Battaglia, A Kobayashi, S Tanelli, S Simmer, C Im, E AF Battaglia, Alessandro Kobayashi, Satoru Tanelli, Simone Simmer, Clemens Im, Eastwood TI Multiple scattering effects in pulsed radar systems: An intercomparison study SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID WEAK-LOCALIZATION; BACKSCATTERING ENHANCEMENT; WEATHER RADAR; LIGHT; MODEL; PRECIPITATION; ANISOTROPY AB In this paper, two different numerical methods capable of computing multiple scattering effects in pulsed-radar systems are compared. Both methods are based on the solution of the time-dependent vectorial form of the radiative transfer equation: one exploits the successive order of scattering approximation, the other a forward Monte Carlo technique. Different benchmark results are presented (including layers of monodisperse spherical water and ice particles), which are of specific interest for W-band spaceborne cloud radars such as CloudSat's or Earth-CARE's cloud profiling radars. Results demonstrate a good agreement between the two methods. The pros and cons of the two models are discussed, with a particular focus on the validity of the second order of scattering approximation. C1 [Battaglia, Alessandro; Simmer, Clemens] Univ Bonn, Inst Meteorol, D-53121 Bonn, Germany. [Kobayashi, Satoru] Appl Mat Inc, Santa Clara, CA 95054 USA. [Tanelli, Simone; Im, Eastwood] CALTECH, Jet Prop Lab, Pasadena, CA USA. RP Battaglia, A (reprint author), Univ Bonn, Inst Meteorol, Huegel 20, D-53121 Bonn, Germany. EM batta@uni-bonn.de RI Simmer, Clemens/M-4949-2013; OI Simmer, Clemens/0000-0003-3001-8642; Battaglia, Alessandro/0000-0001-9243-3484 FU National Aeronautics and Space Administration; NASA New Investigator in Earth Science program; CloudSat project; Deutsche Forschungsgemeinschaft FX The work by Dr. Satoru Kobayashi, Dr. Simone Tanelli, and Dr. Eastwood Im was performed at the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. Support, from the NASA New Investigator in Earth Science program and from the CloudSat project is gratefully acknowledged. Support and a grant from the TOSCA project funded by the Deutsche Forschungsgemeinschaft are acknowledged as well. NR 26 TC 11 Z9 11 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0739-0572 EI 1520-0426 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD SEP PY 2008 VL 25 IS 9 BP 1556 EP 1567 DI 10.1175/2008JTECHA1023.1 PG 12 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 348VL UT WOS:000259238100006 ER PT J AU Alwood, JS Yumoto, K Kondo, H Mojarrab, R Lindsey, DP Beauprc, GS Limoli, CL Almeida, EAC Searby, ND Globus, RK AF Alwood, J. S. Yumoto, K. Kondo, H. Mojarrab, R. Lindsey, D. P. Beauprc, G. S. Limoli, C. L. Almeida, E. A. C. Searby, N. D. Globus, R. K. TI Combined Cs-137 Gamma Irradiation and Hindlimb Unloading Rapidly Decreased Cancellous Bone Volume Fraction in the Mouse Lumbar Vertebrae. SO JOURNAL OF BONE AND MINERAL RESEARCH LA English DT Meeting Abstract CT 30th Annual Meeting of the American-Society-for-Bone-and-Mineral-Research CY SEP 12-16, 2008 CL Montreal, CANADA SP Amer Soc Bone & Mineral Res C1 [Alwood, J. S.] Stanford Univ, Stanford, CA 94305 USA. [Yumoto, K.; Kondo, H.; Mojarrab, R.; Almeida, E. A. C.; Searby, N. D.; Globus, R. K.] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. [Lindsey, D. P.; Beauprc, G. S.] VA Palo Alto Healthcare Syst, Bone & Joint Ctr Excellence, Palo Alto, CA USA. [Limoli, C. L.] Univ Calif Irvine, Irvine, CA USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC BONE & MINERAL RES PI WASHINGTON PA 2025 M ST, N W, STE 800, WASHINGTON, DC 20036-3309 USA SN 0884-0431 J9 J BONE MINER RES JI J. Bone Miner. Res. PD SEP PY 2008 VL 23 BP S494 EP S494 PG 1 WC Endocrinology & Metabolism SC Endocrinology & Metabolism GA 351FX UT WOS:000259411002603 ER PT J AU Yumoto, K Mojarrah, R Arakaki, J Wang, A Hilton, D Almeida, GAC Limoli, C Scarby, ND Globus, RK AF Yumoto, K. Mojarrah, R. Arakaki, J. Wang, A. Hilton, D. Almeida, G. A. C. Limoli, C. Scarby, N. D. Globus, R. K. TI Musculoskeletal Disuse Worsens the Acute Detrimental Effects of Heavy Particle Radiation on Osteoblastogenesis SO JOURNAL OF BONE AND MINERAL RESEARCH LA English DT Meeting Abstract CT 30th Annual Meeting of the American-Society-for-Bone-and-Mineral-Research CY SEP 12-16, 2008 CL Montreal, CANADA SP Amer Soc Bone & Mineral Res C1 [Yumoto, K.; Mojarrah, R.; Arakaki, J.; Wang, A.; Hilton, D.; Almeida, G. A. C.; Scarby, N. D.; Globus, R. K.] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. [Limoli, C.] Univ Calif Irvine, Irvine, CA USA. RI Wang, Angela/B-9944-2008 NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER SOC BONE & MINERAL RES PI WASHINGTON PA 2025 M ST, N W, STE 800, WASHINGTON, DC 20036-3309 USA SN 0884-0431 J9 J BONE MINER RES JI J. Bone Miner. Res. PD SEP PY 2008 VL 23 BP S231 EP S231 PG 1 WC Endocrinology & Metabolism SC Endocrinology & Metabolism GA 351FX UT WOS:000259411001228 ER PT J AU Hunter, GW Dweik, RA AF Hunter, Gary W. Dweik, Raed A. TI Applied breath analysis: an overview of the challenges and opportunities in developing and testing sensor technology for human health monitoring in aerospace and clinical applications SO JOURNAL OF BREATH RESEARCH LA English DT Article AB The aerospace industry requires the development of a range of chemical sensor technologies for such applications as leak detection, emission monitoring, fuel leak detection, environmental monitoring, and fire detection. A family of chemical sensors are being developed based on micromachining and microfabrication technology to fabricate microsensors with minimal size, weight, and power consumption, and the use of nanomaterials and structures to develop sensors with improved stability combined with higher sensitivity. However, individual sensors are limited in the amount of information that they can provide in environments that contain multiple chemical species. Thus, sensor arrays are being developed to address detection needs in such multi-species environments. These technologies and technical approaches have direct relevance to breath monitoring for clinical applications. This paper gives an overview of developing cutting-edge sensor technology and possible barriers to new technology implementation. This includes lessons learned from previous microsensor development, recent work in development of a breath monitoring system, and future directions in the implementation of cutting edge sensor technology. Clinical applications and the potential impact to the biomedical field of miniaturized smart gas sensor technology are discussed. C1 [Hunter, Gary W.] NASA, Glenn Res Ctr, Cleveland, OH USA. [Dweik, Raed A.] Cleveland Clin, Dept Pulm & Crit Care Med, Resp Inst, Cleveland, OH 44106 USA. [Dweik, Raed A.] Cleveland Clin, Dept Pathobiol, Lerner Res Inst, Cleveland, OH 44106 USA. RP Hunter, GW (reprint author), NASA, Glenn Res Ctr, Cleveland, OH USA. FU NHLBI NIH HHS [P01 HL081064-01A1, K23 HL068863, K23 HL068863-06, P01 HL081064, P01 HL081064-03] NR 36 TC 15 Z9 15 U1 5 U2 13 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 1752-7155 J9 J BREATH RES JI J. Breath Res. PD SEP PY 2008 VL 2 IS 3 AR 037020 DI 10.1088/1752-7155/2/3/037020 PG 7 WC Biochemical Research Methods; Respiratory System SC Biochemistry & Molecular Biology; Respiratory System GA V13WD UT WOS:000207696000022 PM 20622933 ER PT J AU Chen, B Lin, X Bacmeister, JT AF Chen, Baode Lin, Xin Bacmeister, Julio T. TI Frequency distribution of daily ITCZ patterns over the western-central Pacific SO JOURNAL OF CLIMATE LA English DT Article ID INTERTROPICAL CONVERGENCE ZONE; SEA-SURFACE TEMPERATURE; AQUA-PLANET MODEL; SYNOPTIC-SCALE DISTURBANCES; GENERAL-CIRCULATION MODELS; TOGA COARE; TROPICAL CIRCULATION; GLOBAL PRECIPITATION; WAVE DISTURBANCES; CUMULUS ACTIVITY AB This study attempts to explore a comprehensive and compact approach for delineating the multiscale and multivariate characteristics of the ITCZ over the western-central Pacific based on daily satellite observations of precipitation, SSTs, and surface winds. Essentially six distinct ITCZ spatial patterns-namely, the north, south, equator, double, full, and weak-are identified according to the daily percentage coverage of deep convection within different latitudinal bands on and off the equator over the western-central Pacific. The evolving structure of the ITCZ over the western-central Pacific is investigated with a focus on the transient statistical characteristics. The relationship between these daily ITCZ patterns and SSTs, and near-surface winds, is also examined. The north (37%), south (24%), and weak (24%) ITCZs represent the three major ITCZ daily patterns over the western-central Pacific, and combined they account for almost 85% of the total number of days within a 10-yr period. The other three ITCZ patterns, namely, the equator (3%), double (6%), and full (5%) ITCZs, occur infrequently. The climatology of the ITCZ, such as monthly, seasonal, and annual means, can be approximately determined by how often and intense these ITCZ daily spatial patterns occur within a specified period. Taking the long-term mean statistics for each ITCZ daily type into account, the double ITCZ deep convection typically observed over the western-central Pacific in monthly, seasonal, and annual mean plots appears to be mainly associated with the frequent occurrence of the north and south ITCZ patterns, instead of the double ITCZ pattern in which an ITCZ appears on each side of the equator simultaneously on a daily basis. Consistent with the strong seasonality in their frequency of occurrence, the three major ITCZ patterns indicate a dominant correspondence with the seasonal meridional migration of warm SSTs. In contrast, the three less frequent ITCZ patterns show a close relationship with the positive or negative SST anomaly over the equatorial central and eastern Pacific, namely, the extension and retraction of the equatorial cool tongue and its strength. Surface wind divergence/convergence does not show any distinct patterns for these ITCZ spatial patterns, suggesting that little relationship between low-level convergence and precipitation can be discerned from daily data. As an application of the method proposed, the frequency distribution of daily ITCZ patterns, as derived from a recent version of the National Aeronautics and Space Administration (NASA) Goddard Earth Observing System (GEOS) general circulation model (GCM), is evaluated against observations. Preliminary comparisons indicate that the GEOS-5 GCM is capable of simulating the correct ITCZ spatial patterns, but their occurrence frequencies can be further improved, in particular, the weak ITCZ and the patterns with fewer occurrences, which may be associated with significantly different control mechanisms and/or feedbacks. C1 [Chen, Baode] Chinese Meteorol Adm, Shanghai Typhoon Inst, Shanghai 200030, Peoples R China. [Lin, Xin; Bacmeister, Julio T.] Univ Maryland, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21201 USA. RP Chen, B (reprint author), Chinese Meteorol Adm, Shanghai Typhoon Inst, 166 Puxi Rd, Shanghai 200030, Peoples R China. EM baode@mail.typhoon.gov.cn FU National Science Foundation of China (NSFC) [40675057]; National Climatic Data Center; NASA Goddard Space Flight Center (GSFC); Global Modeling and Assimilation Office at the NASA GSFC FX This work is supported by the National Science Foundation of China (NSFC) Grant 40675057. The GPCP-1DD data are obtained from the National Climatic Data Center. The daily TMI SST data and SeaWinds, version 3, data on the QuikSCAT satellite are obtained online from the Remote Sensing Systems Web site (http://www.remss.com). X. Lin is supported by the Global Precipitation Measurement (GPM) Project at the NASA Goddard Space Flight Center (GSFC). J. Bacmeister is supported by the Global Modeling and Assimilation Office at the NASA GSFC. Special thanks to three anonymous reviewers for their critical and constructive comments that greatly improved this paper. NR 54 TC 8 Z9 11 U1 0 U2 12 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 SEP PY 2008 VL 21 IS 17 BP 4207 EP 4222 DI 10.1175/2008JCLI1973.1 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 345JC UT WOS:000258991500004 ER PT J AU Kato, S Rose, FG Rutan, DA Charlock, TP AF Kato, Seiji Rose, Fred G. Rutan, David A. Charlock, Thomas P. TI Cloud effects on the meridional atmospheric energy budget estimated from Clouds and the Earth's Radiant Energy System (CERES) data SO JOURNAL OF CLIMATE LA English DT Article ID ANGULAR-DISTRIBUTION MODELS; AVAILABLE POTENTIAL-ENERGY; RADIATIVE FLUX ESTIMATION; GENERAL-CIRCULATION; CLIMATE-RESEARCH; PART I; SATELLITE; OCEAN; METHODOLOGY; PARAMETERIZATION AB The zonal mean atmospheric cloud radiative effect, defined as the difference between the top-of-the-atmosphere (TOA) and surface cloud radiative effects, is estimated from 3 yr of Clouds and the Earth's Radiant Energy System (CERES) data. The zonal mean shortwave effect is small, though it tends to be positive (warming). This indicates that clouds increase shortwave absorption in the atmosphere, especially in midlatitudes. The zonal mean atmospheric cloud radiative effect is, however, dominated by the longwave effect. The zonal mean longwave effect is positive in the tropics and decreases with latitude to negative values (cooling) in polar regions. The meridional gradient of the cloud effect between midlatitude and polar regions exists even when uncertainties in the cloud effect on the surface enthalpy flux and in the modeled irradiances are taken into account. This indicates that clouds increase the rate of generation of the mean zonal available potential energy. Because the atmospheric cooling effect in polar regions is predominately caused by low-level clouds, which tend to be stationary, it is postulated here that the meridional and vertical gradients of the cloud effect increase the rate of meridional energy transport by the dynamics of the atmosphere from the midlatitudes to the polar region, especially in fall and winter. Clouds then warm the surface in the polar regions except in the Arctic in summer. Clouds, therefore, contribute toward increasing the rate of meridional energy transport from the midlatitudes to the polar regions through the atmosphere. C1 [Kato, Seiji; Charlock, Thomas P.] NASA, Langley Res Ctr, Sci Directorate, Hampton, VA 23681 USA. [Kato, Seiji; Rose, Fred G.; Rutan, David A.] Sci Syst & Applicat Inc, Hampton, VA USA. RP Kato, S (reprint author), NASA, Langley Res Ctr, Sci Directorate, Mail Stop 420, Hampton, VA 23681 USA. EM seiji.kato@nasa.gov OI Rose, Fred G/0000-0003-0769-0772 NR 40 TC 9 Z9 9 U1 0 U2 5 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 SEP PY 2008 VL 21 IS 17 BP 4223 EP 4241 DI 10.1175/2008JCLI1982.1 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 345JC UT WOS:000258991500005 ER PT J AU Lin, JL Weickman, KM Kiladis, GN Mapes, BE Schubert, SD Suarez, MJ Bacmeister, JT Lee, MI AF Lin, Jia-Lin Weickman, Klaus M. Kiladis, George N. Mapes, Brian E. Schubert, Siegfried D. Suarez, Max J. Bacmeister, Julio T. Lee, Myong-In TI Subseasonal variability associated with Asian summer monsoon simulated by 14 IPCC AR4 coupled GCMs SO JOURNAL OF CLIMATE LA English DT Article ID MADDEN-JULIAN OSCILLATION; OUTGOING LONGWAVE RADIATION; GENERAL-CIRCULATION MODEL; AIR-SEA INTERACTION; TROPICAL INTRASEASONAL OSCILLATIONS; NORTHERN-HEMISPHERE SUMMER; LOW-FREQUENCY VARIABILITY; ATMOSPHERE-OCEAN MODEL; LARGE-SCALE MODELS; SOUTH CHINA SEA AB This study evaluates the subseasonal variability associated with the Asian summer monsoon in 14 coupled general circulation models (GCMs) participating in the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4). Eight years of each model's twentieth-century climate simulation are analyzed. The authors focus on the three major components of Asian summer monsoon: the Indian summer monsoon (ISM), the western North Pacific summer monsoon (WNPSM), and the East Asian summer monsoon (EASM), together with the two dominant subseasonal modes: the eastward-and northward-propagating boreal summer intraseasonal oscillation (BSIO) and the westward-propagating 12-24-day mode. The results show that current state-of-the-art GCMs still have difficulties and display a wide range of skill in simulating the subseasonal variability associated with Asian summer monsoon. During boreal summer (May-October), most of the models produce reasonable seasonal-mean precipitation over the ISM region, but excessive precipitation over the WNPSM region and insufficient precipitation over the EASM region. In other words, models concentrate their rain too close to the equator in the western Pacific. Most of the models simulate overly weak total subseasonal (2-128 day) variance, as well as too little variance for BSIO and the 12-24-day mode. Only 4-5 models produce spectral peaks in the BSIO and 12-24-day frequency bands; instead, most of the models display too red a spectrum, that is, an overly strong persistence of precipitation. For the seven models with three-dimensional data available, five reproduce the preconditioning of moisture in BSIO but often with a too late starting time, and only three simulate the phase lead of low-level convergence. Interestingly, although models often have difficulty in simulating the eastward propagation of BSIO, they tend to simulate well the northward propagation of BSIO, together with the westward propagation of the 12-24-day mode. The northward propagation in these models is thus not simply a NW-SE-tilted tail protruding off of an eastward-moving deep-tropical intraseasonal oscillation. C1 [Lin, Jia-Lin; Weickman, Klaus M.; Kiladis, George N.] Ohio State Univ, Dept Geog, Columbus, OH 43210 USA. [Lin, Jia-Lin] CIRES Climate Diagnost Ctr, NOAA ESRL, Boulder, CO USA. [Mapes, Brian E.] Univ Miami, RSMAS, Miami, FL USA. [Schubert, Siegfried D.; Suarez, Max J.; Bacmeister, Julio T.; Lee, Myong-In] NASA GSFC Global Modeling & Assimilat Off, Greenbelt, MD USA. [Bacmeister, Julio T.; Lee, Myong-In] Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21228 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 RI Mapes, Brian/A-5647-2010; OI Lee, Myong-In/0000-0001-8983-8624 NR 75 TC 57 Z9 60 U1 1 U2 9 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 SEP PY 2008 VL 21 IS 18 BP 4541 EP 4567 DI 10.1175/2008JCLI1816.1 PG 27 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 350PG UT WOS:000259365000001 ER PT J AU Kharche, N Luisier, M Boykin, TB Klimeck, G AF Kharche, Neerav Luisier, Mathieu Boykin, Timothy B. Klimeck, Gerhard TI Electronic structure and transmission characteristics of SiGe nanowires SO JOURNAL OF COMPUTATIONAL ELECTRONICS LA English DT Article DE Nanowires; SiGe; Brillouin zone-unfolding; Open boundary conditions; NEGF AB Atomistic disorder such as alloy disorder, surface roughness and inhomogeneous strain are known to influence electronic structure and charge transport. Scaling of device dimensions to the nanometer regime enhances the effects of disorder on device characteristics and the need for atomistic modeling arises. In this work SiGe alloy nanowires are studied from two different points of view: (1) Electronic structure where the bandstructure of a nanowire is obtained by projecting out small cell bands from a supercell eigen-spectrum and (2) Transport where the transmission coefficient through the nanowire is computed using an atomistic wave function approach. The nearest neighbor sp(3)d(5)s* semi-empirical tight-binding model is employed for both electronic structure and transport. The connection between dispersions and transmission coefficients of SiGe random alloy nanowires of different sizes is highlighted. Localization is observed in thin disordered wires and a transition to bulk-like behavior is observed with increasing wire diameter. C1 [Kharche, Neerav] Purdue Univ, Network Computat Nanotechnol, W Lafayette, IN 47906 USA. [Klimeck, Gerhard] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Luisier, Mathieu] ETH, Integrated Syst Lab, CH-8092 Zurich, Switzerland. [Boykin, Timothy B.] Univ Alabama, Dept Elect & Comp Engn, Huntsville, AL 35899 USA. RP Kharche, N (reprint author), Purdue Univ, Network Computat Nanotechnol, W Lafayette, IN 47906 USA. EM nkharche@purdue.edu RI Kharche, Neerav/F-4331-2015; Klimeck, Gerhard/A-1414-2012 OI Kharche, Neerav/0000-0003-1014-6022; Klimeck, Gerhard/0000-0001-7128-773X FU Semiconductor Research Corporation; National Science Foundation FX This work was supported by Semiconductor Research Corporation. Calculations were performed on nanoHUB.org resources provided by the Network for Computational Nanotechnology, funded by the National Science Foundation. NR 18 TC 5 Z9 5 U1 0 U2 10 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1569-8025 J9 J COMPUT ELECTRON JI J. Comput. Electron. PD SEP PY 2008 VL 7 IS 3 SI SI BP 350 EP 354 DI 10.1007/s10825-008-0191-9 PG 5 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA V25JH UT WOS:000208473800060 ER PT J AU Saini, S Ciotti, R Gunney, BTN Spelce, TE Koniges, A Dossa, D Adamidis, P Rabenseifner, R Tiyyagura, SR Mueller, M AF Saini, Subhash Ciotti, Robert Gunney, Brian T. N. Spelce, Thomas E. Koniges, Alice Dossa, Don Adamidis, Panagiotis Rabenseifner, Rolf Tiyyagura, Sunil R. Mueller, Matthias TI Performance evaluation of supercomputers using HPCC and IMB benchmarks SO JOURNAL OF COMPUTER AND SYSTEM SCIENCES LA English DT Article; Proceedings Paper CT 5th International Workshop on Performance Modelling, Evaluation, and Optimization of Parallel and Distributed Systems CY APR 29, 2006 CL Rhodes Isl, GREECE DE HPCC; IMB; performance evaluation; supercomputer architectures; interconnect performance ID LINEAR ALGEBRA SUBPROGRAMS; SET AB The HPC Challenge (HPCC) Benchmark Suite and the Intel MPI Benchmark (IMB) are used to compare and evaluate the combined performance of processor, memory subsystem and interconnect fabric of five leading supercornputers-SGI Affix BX2, Cray X1, Cray Opteron Cluster, Dell Xeon Cluster, and NEC SX-8. These five systems use live different networks (SGI NUMALINK4, Cray network, Myrinet, InfiniBand, and NEC IXS). The complete set of HPCC Benchmarks are run oil each of these systems. Additionally, we present Intel MPI Benchmarks results to study the performance of I I MPI communication functions on these systems. (C) 2007 Elsevier Inc. All rights reserved. C1 [Saini, Subhash; Ciotti, Robert] NASA, Ames Res Ctr, NASA Adv Supercomp, Moffett Field, CA 94035 USA. [Gunney, Brian T. N.; Spelce, Thomas E.; Koniges, Alice; Dossa, Don] Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. [Adamidis, Panagiotis] German Climate Comp Ctr, Hamburg, Germany. [Mueller, Matthias] Tech Univ Dresden, ZIH, D-01069 Dresden, Germany. [Rabenseifner, Rolf; Tiyyagura, Sunil R.] Univ Stuttgart, High Performance Comp Ctr HLRS, D-70550 Stuttgart, Germany. RP Saini, S (reprint author), NASA, Ames Res Ctr, NASA Adv Supercomp, Moffett Field, CA 94035 USA. EM ssaini@nas.nasa.gov; ciotti@nas.nasa.gov; gunney@llnl.gov; koniges@llnl.gov; dossal@llnl.gov; adamidis@dkrz.de; rabenseifner@hlrs.de; sunil@hlrs.de; matthias.mueller@tu-dresden.de NR 19 TC 9 Z9 9 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 0022-0000 J9 J COMPUT SYST SCI JI J. Comput. Syst. Sci. PD SEP PY 2008 VL 74 IS 6 BP 965 EP 982 DI 10.1016/j.jcss.2007.07.002 PG 18 WC Computer Science, Hardware & Architecture; Computer Science, Theory & Methods SC Computer Science GA 342NU UT WOS:000258791600003 ER PT J AU Desai, PN Conway, BA AF Desai, Prasun N. Conway, Bruce A. TI Six-degree-of-freedom trajectory optimization using a two-timescale collocation architecture SO JOURNAL OF GUIDANCE CONTROL AND DYNAMICS LA English DT Article; Proceedings Paper CT AIAA/AAS Astrodynamics Specialist Conference CY AUG 07-11, 2005 CL Lake Tahoe, CA SP Amer Inst Aeronaut & Astronaut, Amer Astronaut Soc ID HL-20 AB Six-degree-of-freedom trajectory optimization or a reentry vehicle is performed using a two-timescale collocation methodology. This class or six-degree-of-freedom trajectory problems is characterized by two distinct timescales in their governing equations, in which a subset of the states have high-frequency dynamics (the rotational equations of motion), whereas the remaining states (the translational equations of motion) vary comparatively slowly. With conventional collocation methods, the six-degree-of-freedom problem becomes extraordinarily large and the problem becomes difficult to solve. Using the two-timescale collocation architecture, the problem size is reduced significantly. The converged solution shows a realistic landing profile and captures the appropriate high-frequency rotational dynamics. A large reduction in the overall problem size (by 55%) is attained with the two-timescale architecture as compared to the conventional single-timescale collocation method. Consequently, optimum six-degree-of-freedom trajectories can now be found efficiently using collocation, which was not previously possible for a system with two distinct timescales in the governing states. C1 [Desai, Prasun N.] NASA, Langley Res Ctr, Atmospher Flight & Entry Syst Branch, Hampton, VA 23681 USA. [Conway, Bruce A.] Univ Illinois, Dept Aerosp Engn, Talbot Lab 306, Urbana, IL 61801 USA. RP Desai, PN (reprint author), NASA, Langley Res Ctr, Atmospher Flight & Entry Syst Branch, 1 N Dryden St,Mail Stop 489, Hampton, VA 23681 USA. EM prasun.n.desai@nasa.gov; bconway@uiuc.edu NR 15 TC 13 Z9 20 U1 0 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 SEP-OCT PY 2008 VL 31 IS 5 BP 1308 EP 1315 DI 10.2514/1.34020 PG 8 WC Engineering, Aerospace; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 349FB UT WOS:000259265600012 ER PT J AU Desai, PN Conway, BA AF Desai, Prasun N. Conway, Bruce A. TI Two-timescale discretization scheme for collocation SO JOURNAL OF GUIDANCE CONTROL AND DYNAMICS LA English DT Article AB The development of a two-timescale discretization scheme for collocation is presented. This scheme allows a coarser discretization to be used for slowly varying state variables and a second finer discretization to be used for state variables having higher-frequency dynamics. That is, the discretization scheme can be tailored to the dynamics of the particular state variables. Consequently, the size of the overall nonlinear programming problem can be reduced significantly. Two two-timescale discretization architecture schemes are described. Comparison of results between the two-timescale method and conventional single-timescale collocation shows very good agreement. When the two-timescale discretization is used in combination with the sparse nonlinear optimizer SNOPT, a significant reduction (by more than 60%) in the number of nonlinear programming parameters required for the transcription of the problem and iterations necessary for convergence can he achieved without sacrificing solution accuracy. C1 [Desai, Prasun N.] NASA, Langley Res Ctr, Atmospher Flight & Entry Syst Branch, Hampton, VA 23681 USA. [Conway, Bruce A.] Univ Illinois, Dept Aerosp Engn, Talbot Lab 306, Urbana, IL 61801 USA. RP Desai, PN (reprint author), NASA, Langley Res Ctr, Atmospher Flight & Entry Syst Branch, 1 N Dryden St,MS 489, Hampton, VA 23681 USA. EM prasun.n.desai@nasa.gov; bconway@uiuc.edu NR 9 TC 4 Z9 4 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 SEP-OCT PY 2008 VL 31 IS 5 BP 1316 EP 1322 DI 10.2514/1.33974 PG 7 WC Engineering, Aerospace; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 349FB UT WOS:000259265600013 ER PT J AU Nerger, L Gregg, WW AF Nerger, Lars Gregg, Watson W. TI Improving assimilation of SeaWiFS data by the application of bias correction with a local SEIK filter SO JOURNAL OF MARINE SYSTEMS LA English DT Article DE data assimilation; ecosystem modeling; Kalman filter; SEIK; bias correction; ocean color; ocean chlorophyll ID ENSEMBLE KALMAN FILTER; BIOGEOCHEMICAL MODEL; FORECAST BIAS; OCEAN MODEL; CRETAN SEA AB Ocean-biogeochemical models show typically significant errors in the representation of chlorophyll concentrations. The model state can be improved by the assimilation of satellite chlorophyll data with algorithms based on the Kalman filter. However, these algorithms do usually not account for the possibility that the model prediction contains systematic errors in the form of model bias. Accounting explicitly for model biases can improve the assimilation performance. To study the effect of bias estimation on the estimation of surface chlorophyll concentrations, chlorophyll data from the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) are assimilated on a daily basis into the NASA Ocean Biogeochemical Model (NOBM). The assimilation is performed by the ensemble-based SEIK filter combined with an online bias correction scheme. The SEIK filter is simplified here by the use of a static error covariance matrix. The performance of the filter algorithm is assessed by comparison with independent in situ data over the 7-year period 1998-2004. The bias correction results in significant improvements of the surface chlorophyll concentrations compared to the assimilation without bias estimation. With bias estimation, the daily surface chlorophyll estimates from the assimilation show about 3.3% lower error than SeaWiFS data. In contrast, the error in the global surface chlorophyll estimate without bias estimation is 10.9% larger than the error of SeaWiFS data. (C) 2007 Elsevier B.V. All rights reserved. C1 [Nerger, Lars; Gregg, Watson W.] NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Greenbelt, MD 20771 USA. [Nerger, Lars] Univ Maryland, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21201 USA. RP Nerger, L (reprint author), Alfred Wegener Inst Polar & Marine Res, D-27570 Bremerhaven, Germany. EM lars.nerger@awi.de RI Nerger, Lars/G-4845-2013 OI Nerger, Lars/0000-0002-1908-1010 NR 24 TC 14 Z9 14 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0924-7963 J9 J MARINE SYST JI J. Mar. Syst. PD SEP PY 2008 VL 73 IS 1-2 BP 87 EP 102 DI 10.1016/j.jmarsys.2007.09.007 PG 16 WC Geosciences, Multidisciplinary; Marine & Freshwater Biology; Oceanography SC Geology; Marine & Freshwater Biology; Oceanography GA 347HA UT WOS:000259130000007 ER PT J AU Cody, WL Wilson, JW Hendrixson, DR McIver, KS Hagman, KE Ott, CM Nickerson, CA Schurr, MJ AF Cody, William L. Wilson, James W. Hendrixson, David R. McIver, Kevin S. Hagman, Kayla E. Ott, C. M. Nickerson, Cheryl A. Schurr, Michael J. TI Skim milk enhances the preservation of thawed-80 degrees C bacterial stocks SO JOURNAL OF MICROBIOLOGICAL METHODS LA English DT Article DE cryopreservation; skim milk; bacterial strain; glycerol ID PSEUDOMONAS-AERUGINOSA; PROTECTIVE ACTION; STREPTOCOCCUS; SURVIVAL; GLYCEROL; PLASMID; STORAGE; STRAIN; GROWTH; MEDIA AB The results from bacterial strain recovery efforts following hurricanes Katrina and Rita are reported. Over 90% of strains frozen in 10% skim milk were recovered whereas various recovery rates were observed for glycerol-stored stocks (56% and 94% of Escherichia coli, depending upon the laboratory). These observations led to a viability comparison of Streptococcus pyogenes, Campylobacter jejuni, Borrelia burgdorferi, Salmonella enterica subsp. Typhimurium, Pseudomonas aeruginosa and E. coli strains stored in glycerol or skim milk. In all bacteria examined, 10% skim milk resulted in significantly longer viability after thawing than 15% glycerol solutions currently used in most laboratories. (C) 2008 Elsevier B.V. All rights reserved. C1 [Cody, William L.; Schurr, Michael J.] Univ Colorado Denver, Dept Microbiol, Sch Med, Aurora, CO 80045 USA. [Wilson, James W.; Nickerson, Cheryl A.] Arizona State Univ, Biodesign Inst, Ctr Infect Dis & Vaccinol, Tempe, AZ 85287 USA. [Hendrixson, David R.; McIver, Kevin S.; Hagman, Kayla E.] Univ Texas SW Med Ctr Dallas, Dept Microbiol, Dallas, TX 75390 USA. [Ott, C. M.] NASA Johnson, Space Ctr, Habitabil & Environm Factors Div, Houston, TX 77058 USA. RP Schurr, MJ (reprint author), Univ Colorado Denver, Dept Microbiol, Sch Med, MS8333,12800 E 19th Ave, Aurora, CO 80045 USA. EM michael.schurr@uchsc.edu RI McIver, Kevin/K-9657-2016 OI McIver, Kevin/0000-0002-4769-4463 FU NIH [RO1A150812, RO1A151332, RO1A147928]; NASA [NAG 2-1378, NAG9-1350, NCC 2-1362]; President's Research Council of the University of Texas Southwestern Medical Cente FX This study was supported by NIH grant RO1A150812 to M.J.S, NASA grants NAG 2-1378, NAG9-1350, and NCC 2-1362 to C.A.N., NIH grant RO1A151332 to K.E.H., RO1A147928 to K.S.M., Distinguished Young Investigator Award from the President's Research Council of the University of Texas Southwestern Medical Center to D.R.H. We thank Dr. Duane Pierson and his lab at the NASA Johnson Space Center and the Department of Microbiology at the University of Texas Southwestern Medical Center (UTSMC) at Dallas for their invaluable help in preserving our strains, and to Dr. Michael Norgard and UTSMC for hosting the Schurr laboratory following the hurricane. In addition, we thank Dr. Margaret Park for her help during the challenging recovery effort of strains at Tulane. NR 27 TC 7 Z9 8 U1 7 U2 16 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-7012 J9 J MICROBIOL METH JI J. Microbiol. Methods PD SEP PY 2008 VL 75 IS 1 BP 135 EP 138 DI 10.1016/j.mimet.2008.05.006 PG 4 WC Biochemical Research Methods; Microbiology SC Biochemistry & Molecular Biology; Microbiology GA 351LU UT WOS:000259426600019 PM 18573555 ER PT J AU Drouin, BJ Muller, HSP AF Drouin, Brian J. Mueller, Holger S. P. TI Special issue dedicated to the pioneering work of Drs. Edward A. Cohen and Herbert M. Pickett on spectroscopy relevant to the Earth's atmosphere and astrophysics SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Editorial Material ID MOLECULAR-SPECTROSCOPY; COLOGNE DATABASE; CDMS C1 [Drouin, Brian J.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Mueller, Holger S. P.] Univ Cologne, Inst Phys 1, D-50937 Cologne, Germany. RP Drouin, BJ (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM hspm@ph1.uni-koeln.de OI Mueller, Holger/0000-0002-0183-8927 NR 5 TC 5 Z9 5 U1 0 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 SEP-OCT PY 2008 VL 251 IS 1-2 BP 1 EP 3 DI 10.1016/j.jms.2008.05.004 PG 3 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA 347UY UT WOS:000259167900001 ER PT J AU Robichaud, DJ Hodges, JT Maslowski, P Yeung, LY Okumura, M Miller, CE Brown, LR AF Robichaud, David J. Hodges, Joseph T. Maslowski, Piotr Yeung, Laurence Y. Okumura, Mitchio Miller, Charles E. Brown, Linda R. TI High-accuracy transition frequencies for the O-2 A-band SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article DE oxygen; frequency standard; cavity ring-down; laser spectroscopy; A-band; O-2; high-resolution ID RING-DOWN SPECTROSCOPY; HIGH-PRECISION; ABSORPTION-SPECTROSCOPY; HYPERFINE-STRUCTURE; LASER SPECTROSCOPY; LINE PARAMETERS; DIODE-LASER; OXYGEN; STATE; PRESSURE AB Frequencies for 32 P-branch transitions of the O-2 A-band (b(1)Sigma(+)(g) -> X-3 Sigma(-)(u) were measured between 12975 and 13 115 cm(-1) using the frequency-stabilized cavity ring-down spectrometer located at National Institute of Standards and Technology, Gaithersburg, MD. Absolute line positions were calibrated using the hyperfine components of 39K D-1 and D-2 atomic transitions yielding uncertainties <1 MHz (similar to 3 x 10(-5) cm(-1)). Spectroscopic parameters for the b(1)Sigma(+)(g)(V = 0) state were calculated and compared with previously determined values. These new transition frequencies should serve as a convenient secondary calibration standard in the 760 nm region. (C) 2007 Elsevier Inc. All rights reserved. C1 [Hodges, Joseph T.; Maslowski, Piotr] NIST, Proc Measurements Div, Gaithersburg, MD 20899 USA. [Robichaud, David J.; Yeung, Laurence Y.; Okumura, Mitchio] CALTECH, Div Chem & Chem Engn, Pasadena, CA 91125 USA. [Maslowski, Piotr] Uniwersytet Mikolaja Kopernika, Inst Fizyki, PL-87100 Torun, Poland. [Miller, Charles E.; Brown, Linda R.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Hodges, JT (reprint author), NIST, Proc Measurements Div, 100 Bur Dr, Gaithersburg, MD 20899 USA. EM joseph.hodges@nist.gov; mo@caltech.edu; charles.e.miller@jpl.nasa.gov; Linda.R.Brown@jpl.nasa.gov RI Hodges, Joseph/B-4578-2009; Yeung, Laurence/D-4574-2009; Maslowski, Piotr/H-4476-2014; Okumura, Mitchio/I-3326-2013 OI Yeung, Laurence/0000-0001-9901-2607; Maslowski, Piotr/0000-0001-8882-7106; Okumura, Mitchio/0000-0001-6874-1137 FU California Institute of Technology; National Aeronautics and Space Administration (NASA) [NNG06GD88G]; Orbiting Carbon Observatory (OCO); NIST; Environmental Science and the Dow Chemical Company Travel Fellowship FX Part of the research described in this paper was performed at the Jet Propulsion Laboratory, California Institute of Technology, under contract with The National Aeronautics and Space Administration (NASA). Additional support was provided by the Orbiting Carbon Observatory (OCO) project, a NASA Earth System Science Pathfinder (ESSP) mission; the NASA Upper Atmospheric Research Program Grant NNG06GD88G; and the NIST Office of Microelectronics Programs. L.Y.Y. acknowledges the support of the Davidow Graduate Fellowship in Environmental Science and the Dow Chemical Company Travel Fellowship. We thank Jeffrey Anderson (NIST Fabrication Technology Division) for preparing the potassium reference cell, Dr. Roman Ciurylo (Uniwersytet Mikolaja Kopernika) for Useful discussions oil saturation spectroscopy and Drs. Craig Sansonetti (NIST Atomic Physics Division) and Alan Pine for carefully reviewing the manuscript and offering important suggestions. NR 42 TC 50 Z9 49 U1 1 U2 13 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 SEP-OCT PY 2008 VL 251 IS 1-2 BP 27 EP 37 DI 10.1016/j.jms.2007.12.008 PG 11 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA 347UY UT WOS:000259167900006 ER PT J AU Toth, RA Miller, CE Brown, LR Devi, VM Benner, DC AF Toth, R. A. Miller, C. E. Brown, L. R. Devi, V. Malathy Benner, D. Chris TI Line strengths of (OCO)-O-16-C-13-O-16, (OCO)-O-16-C-13-O-18, (OCO)-O-16-C-13-O-17 and (OCO)-O-18-C-13-O-18 between 2200 and 6800 cm(-1) SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article DE carbon dioxide; isotopes; line positions; intensities; near-infrared; enriched samples ID CONSTRAINED MULTISPECTRUM ANALYSIS; NEAR-INFRARED SPECTROSCOPY; SELF-BROADENED WIDTHS; CW-CAVITY RINGDOWN; CARBON-DIOXIDE; FREQUENCY MEASUREMENTS; SPEED DEPENDENCE; MU-M; POSITIONS; (CO2)-C-12-O-16 AB Line position and strengths of (OCO)-O-16-C-13-O-16 (636) (OCO)-O-16-C-13-O-18 (638) and (OCO)-O-16-C-13-O-17(637), and (OCO)-O-18-C-13-O-18 (838) bands were measured using natural and C-13- and O-18-enriched samples of CO2 at room temperature. Twenty-five near infrared (NIR) absorption spectra were recorded at 0.01-0.013 cm(-1) resolution with the McMath-Pierce Fourier transform spectrometer located at the National Solar Observatory on Kitt Peak, Arizona. Absorption cells with optical path lengths ranging from 0.347 m to 385 in were used with pressures ranging between 0.5 and 147 torr. Line strengths were obtained Cor 17 bands of (636) between 4697 and 6797 cm(-1), 13 bands of (638) between 2192 and 4954 cm(-1), 4 bands of (637) between 3437 and 4981 cm(-1) and 7 bands of (838) between 2182 and 4888 cm(-l). Band strengths and Herman-Wallis-like F-factor coefficients were determined from least-squares fits to over 2000 measured transition intensities involving 41 different bands. The observed line positions of several bands were analyzed to obtain the upper state term values and rotational constants. Five of the (OCO)-O-18-C-13-O-18 bands and two of the (OCO)-O-16-C-13-O-18 bands were modeled for the first time. (C) 2008 Elsevier Inc. All rights reserved. C1 [Toth, R. A.; Miller, C. E.; Brown, L. R.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Devi, V. Malathy; Benner, D. Chris] Coll William & Mary, Dept Phys, Williamsburg, VA 23187 USA. RP Toth, RA (reprint author), CALTECH, Jet Prop Lab, MS 183-301,4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Robert.A.Toth@jpl.nasa.gov FU National Science Foundation [ATM-0338475] FX The authors thank Michael Dulick and the National Solar Observatory on Kitt Peak for the use of the FTS and for assistance in obtaining the data. Part of the research described in this paper was performed at the Jet Propulsion laboratory, California Institute of Technology, under contracts and cooperative agreements with the National Aeronautics and Space Administration. Tills material is also based upon work at the College of William and Mary supported by the National Science Foundation under Grant No. ATM-0338475. NR 24 TC 20 Z9 20 U1 0 U2 6 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 SEP-OCT PY 2008 VL 251 IS 1-2 BP 64 EP 89 DI 10.1016/j.jms.2008.01.009 PG 26 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA 347UY UT WOS:000259167900009 ER PT J AU Groner, P Medvedev, IR De Lucia, FC Drouin, BJ AF Groner, Peter Medvedev, Ivan R. De Lucia, Frank C. Drouin, Brian J. TI Rotational spectrum of acetone, CH3COCH3, in the nu(17) torsional excited state SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article DE acetone; rotational spectroscopy; internal rotation; torsional excited state ID SUBMILLIMETER-WAVE SPECTRUM; MILLIMETER-WAVE; GROUND-STATE; LABORATORY ASSIGNMENTS; INTERSTELLAR ACETONE; POTENTIAL FUNCTION; INTERNAL-ROTATION; MICROWAVE-SPECTRA; PREDICTIONS; GHZ AB The rotational spectrum of acetone in its second torsional excited state (nu(17), 125 cm(-1) above the ground state) has been identified and assigned. The interaction between overall rotation and the internal rotation motions Causes rotational transitions to split into four components, one for each torsional substate. The splittings in this torsional excited state are significantly larger than any splittings assigned yet for molecules with two methyl internal rotors, making assignments rather difficult. Over 700 frequencies between 72 and 372 GHz in the sub-millimeter wave spectrum have been assigned to R-b-transitions in all four torsional substates. Eventually, 32 parameters of an effective rotational Hamiltonian for a molecule with two periodic internal motions were fit to observed frequencies of 612 transitions from all torsional substates with a standard deviation of 0.485 MHz. (c) 2008 Elsevier Inc. All rights reserved. C1 [Groner, Peter] Univ Missouri, Dept Chem, Kansas City, MO 64110 USA. [Medvedev, Ivan R.; De Lucia, Frank C.] Ohio State Univ, Dept Phys, Columbus, OH 43210 USA. [Drouin, Brian J.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Groner, P (reprint author), Univ Missouri, Dept Chem, Kansas City, MO 64110 USA. EM gronerp@umkc.edu RI Medvedev, Ivan/E-8486-2014 FU NASA; California Institute of Technology FX Laboratory astrophysics at The Ohio State University is supported by NASA. Portions of this paper present research carried out at the jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of NASA. NR 24 TC 8 Z9 9 U1 0 U2 7 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 SEP-OCT PY 2008 VL 251 IS 1-2 BP 180 EP 184 DI 10.1016/j.jms.2008.02.018 PG 5 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA 347UY UT WOS:000259167900020 ER PT J AU Drouin, BJ Gamache, RR AF Drouin, Brian J. Gamache, Robert R. TI Temperature dependent air-broadened linewidths of ozone rotational transitions SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article DE ozone; air broadening; atmospheric chemistry ID MOLECULAR SPECTROSCOPIC DATABASE; PRESSURE-INDUCED LINESHAPE; ASYMMETRIC-TOP MOLECULES; SPECTRAL-LINES; SHIFT COEFFICIENTS; MULTIPOLE MOMENTS; O-3 LINES; SUBMILLIMETER; NITROGEN; OXYGEN AB Ozone resonant features in the rotational band are useful for composition measurements in the stratosphere and upper troposphere. However, the density of ozone features in the long wavelengths often decreases precision of other trace species measurements, especially when insufficient spectral parameters exist. This work presents systematic studies of temperature dependent air-broadened linewidth parameters for ozone. Eighteen new experimental measurements are presented and compared with 57 calculated parameters that cover spectral regions Currently probed by the Earth Observing System-Microwave Limb Sounder. Comparisons with previous measurements and similar broadening studies in the infrared wavelengths are made. Published by Elsevier Inc. C1 [Drouin, Brian J.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Gamache, Robert R.] Univ Massachusetts, Dept Environm Earth & Atmospher Sci, Lowell, MA 01854 USA. [Gamache, Robert R.] Univ Massachusetts, Sch Marine Sci, Lowell, MA 01854 USA. RP Drouin, BJ (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,Mail Stop 183-301, Pasadena, CA 91109 USA. EM brain.j.drouin@jpl.nasa.gov FU National Science Foundation (NSF) [ATM-0242537] FX This research was performed at the jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. One of the authors (R.R.G.) is pleased to acknowledge support of this research by the National Science Foundation (NSF) through Grant No. ATM-0242537. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the NSF. NR 65 TC 4 Z9 6 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 0022-2852 EI 1096-083X J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD SEP-OCT PY 2008 VL 251 IS 1-2 BP 194 EP 202 DI 10.1016/j.jms.2008.02.016 PG 9 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA 347UY UT WOS:000259167900022 ER PT J AU Podobedov, VB Plusquellic, DF Siegrist, KM Fraser, GT Ma, Q Tipping, RH AF Podobedov, V. B. Plusquellic, D. F. Siegrist, K. M. Fraser, G. T. Ma, Q. Tipping, R. H. TI Continuum and magnetic dipole absorption of the water vapor-oxygen mixtures from 0.3 to 3.6 THz SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article DE continuum; IR; THz; oxygen; water vapor; atmosphere ID WING LINE-SHAPE; ATMOSPHERIC WINDOW; COORDINATE REPRESENTATION; STATISTICAL-THEORY; ROTATIONAL BANDS; PRESSURE; REGION; SPECTROSCOPY; TEMPERATURES; SPECTRUM AB The measurement of absorbance in water vapor-oxygen mixtures is reported for the far-IR region from 10 to 120 cm(-1) (0.3-3.6 THz). The experiments were performed in a temperature-stabilized multipass absorption cell Coupled to a far-infrared Fourier transform spectrometer with a liquid-He-cooled bolometer detector. The absorbance components due to both the H2O-O-2 continuum and the oxygen magnetic dipole discrete lines have been measured in the temperature range from 294 to 333 K with a spectral resolution of 0.03 to 0.07 cm(-1). In the range up to 2.5 THz, the H2O-O-2 continuum demonstrates a nearly quadratic dependence of absorbance on frequency, while in the 3.43 THz window deviation from this dependence was detected. The series of rotational lines associated with magnetic dipole transitions was measured in pure oxygen. In the mixture of 1.36 kPa of water vapor and 79.2 kPa of oxygen, a comparable contribution from continuum and discrete lines associated with magnetic dipole transitions of O-2 was observed. The absorption coefficient of 0.066 (dB/km)/(kPa THz)(2) and its temperature exponent of 4.7 were measured for the H2O-O-2 continuum. Experimental continua data compared to theoretically predicted Values exhibit good agreement. The modeling of the resonant water vapor spectrum was performed using a Van Vleck-Weisskopf lineshape with a 215 cm(-1) far-wing cut-off and the HITRAN2004 database. Published by Elsevier Inc. C1 [Podobedov, V. B.; Plusquellic, D. F.; Siegrist, K. M.; Fraser, G. T.] NIST, Opt Technol Div, Gaithersburg, MD 20899 USA. [Ma, Q.] Columbia Univ, Dept Appl Phys & Appl Math, NASA, Goddard Inst Space Studies, New York, NY 10025 USA. [Tipping, R. H.] Univ Alabama, Dept Phys & Astron, Tuscaloosa, AL 35487 USA. RP Podobedov, VB (reprint author), NIST, Opt Technol Div, 100 Bur Dr, Gaithersburg, MD 20899 USA. EM Vyacheslav.Podobedov@nist.gov FU NASA [NNH05AB211, NAG5-13337, NNG06GB23G, FCCS-547] FX The authors from NIST acknowledge with thanks support from the Upper Atmospheric Research Program of NASA, Grant NNH05AB211. Ma and Tippiing acknowledge financial support from NASA under Grants NAG5-13337, NNG06GB23G, and FCCS-547. The authors would like to thank the National Energy Research Scientific Computing Center (Livermore, CA) for computer time and facilities provided. NR 35 TC 8 Z9 8 U1 1 U2 10 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 SEP-OCT PY 2008 VL 251 IS 1-2 BP 203 EP 209 DI 10.1016/j.jms.2008.02.021 PG 7 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA 347UY UT WOS:000259167900023 ER PT J AU Xu, LH Fisher, J Lees, RM Shi, HY Hougen, JT Pearson, JC Drouin, BJ Blake, GA Braakman, R AF Xu, Li-Hong Fisher, J. Lees, R. M. Shi, H. Y. Hougen, J. T. Pearson, J. C. Drouin, B. J. Blake, G. A. Braakman, R. TI Torsion-rotation global analysis of the first three torsional states (nu(t)=0, 1, 2) and terahertz database for methanol SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article DE large amplitude internal rotational motion; microwave; millimeter wave; terahertz; global modeling; Fourier transform ID SUBMILLIMETER-WAVE SPECTRUM; MILLIMETER-WAVE; MOLECULAR-PARAMETERS; INTERNAL ROTOR; ADDITIONAL MEASUREMENTS; PERDEUTERATED METHANOL; REST FREQUENCIES; TRANSITIONS; FIT; THZ AB Stimulated by recent THz measurements of the methanol spectrum in one of our laboratories, undertaken in support of NASA programs related to the Herschel Space Observatory (HSO) and the Atacama Large Millimeter Array (ALMA), we have carried Out a global analysis of available microwave and high-resolution infrared data for the first three torsional states (nu(t) = 0, 1, 2), and for J values up to 30. This global fit of approximately 5600 frequency measurements and 19000 Fourier transform far infrared (FTFIR) wavenumber measurements to 119 parameters reaches the estimated experimental measurement accuracy for the FTFIR transitions, and about twice the estimated experimental measurement accuracy for the microwave, submillimeter-wave, and terahertz transitions. The present fit is essentially a continuation Of Our earlier work, but we have greatly expanded our previous data set and have added a large number of new torsion-rotation interaction terms to the Hamiltonian in Our previously used Computer program. The results, together with a number of calculated (but unmeasured) transitions, including their line strength, estimated uncertainty, and lower state energy, are made available in the supplementary material as a database formatted to be useful for astronomical searches. Some discussion of several open spectroscopic problems, e.g., (i) an improved notation for the numerous parameters in the torsion-rotation Hamiltonian, (ii) possible causes of the failure to fit frequency measurements to the estimated measurement uncertainty, and (iii) pitfalls to be avoided when intercomparing apparently identical parameters from the internal axis method and the rho axis method are also given. (C) 2008 Elsevier Inc. All rights reserved. C1 [Xu, Li-Hong; Fisher, J.; Lees, R. M.; Shi, H. Y.] Univ New Brunswick, Dept Phys, CLAMS, St John, NB E2L 4L5, Canada. [Hougen, J. T.] NIST, Opt Technol Div, Gaithersburg, MD 20899 USA. [Pearson, J. C.; Drouin, B. J.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Blake, G. A.; Braakman, R.] CALTECH, Dept Chem & Chem Engn, Pasadena, CA 91109 USA. RP Xu, LH (reprint author), Univ New Brunswick, Dept Phys, CLAMS, POB 5050, St John, NB E2L 4L5, Canada. EM lxu@unbsj.ca RI Xu, Li-Hong/J-5095-2015 FU Natural Sciences and Engineering Research Council of Canada; NSERC-USRA FX The authors thank Drs. 1. Kleiner and M. Godefroid for making their acetaldehyde (CH3CHO) internal rotation global fitting program available for this work. L.HX and R.M.L. thank the Natural Sciences and Engineering Research Council of Canada for financial support of this research program. J. Fisher is grateful for NSERC-USRA (Undergraduate Summer Research Award) support. Portions of the research described in this paper were carried out at the jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. Copyright 2008 California Institute of Technology. Government sponsorship acknowledged. NR 39 TC 72 Z9 72 U1 2 U2 20 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 SEP-OCT PY 2008 VL 251 IS 1-2 BP 305 EP 313 DI 10.1016/j.jms.2008.03.017 PG 9 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA 347UY UT WOS:000259167900038 ER PT J AU Petkie, DT Kipling, M Jones, A Helminger, P Medvedev, IR Atsuko, M Behnke, M Drouin, BJ Miller, CE AF Petkie, Douglas T. Kipling, Mark Jones, Ashley Helminger, Paul Medvedev, Ivan R. Atsuko, Maeda Behnke, Markus Drouin, Brian J. Miller, Charles E. TI The rotational spectra of the 6(1), 7(1), 8(1), 9(1) and 5(1)/9(2) vibrational states of (HNO3)-N-15 SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article DE nitric acid; isotope; rotational spectroscopy; torsional splitting; Coriolis resonance; Fermi resonance; centrifugal distortion ID NITRIC-ACID; SPECTROSCOPIC CONSTANTS; MICROWAVE SPECTRUM; MILLIMETER-WAVE; LINE POSITIONS; 2-NU(9) BANDS; HNO3; SUBMILLIMETER; NU(8); NU(7) AB The high-resolution rotational spectrum of (HNO3)-N-15 has been recorded in the range between 74 and 850 GHz and used to complete ail extensive analysis of the six vibrational states below 1000 cm(-1) that include the isolated 8(1) and 9(1) states along with the weakly interacting 6(1) and 7(1) states and strongly interacting 5(1) and 9(2) dyad. The 6(1) and 7(1) states Couple via a weak Coriolis interaction while the 5(1) and 9(1) states Couple through strong Fermi and weaker Coriolis interactions. The Hamiltonian models account for the observed torsional splitting in the 9(1) and 9(2) states of 2.4 and 70 MHz, respectively, and the induced torsional spitting of 15 MHz in the 5(1) state due to the strong Fermi mixing with the 9(2) state. The transitions from each state are fit to within the experimental accuracy and the resulting spectroscopic constants agree well with the main isotopologue. (C) 2008 Elsevier Inc. All rights reserved. C1 [Petkie, Douglas T.; Kipling, Mark; Jones, Ashley] Wright State Univ, Dept Phys, Dayton, OH 45435 USA. [Helminger, Paul] Univ S Alabama, Dept Phys, Mobile, AL 36688 USA. [Medvedev, Ivan R.; Atsuko, Maeda; Behnke, Markus] Ohio State Univ, Dept Phys, Columbus, OH 43210 USA. [Drouin, Brian J.; Miller, Charles E.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Petkie, DT (reprint author), Wright State Univ, Dept Phys, 248 Fawcett Hall,3640 Colonel Glenn Hwy, Dayton, OH 45435 USA. EM doug.petkie@wright.edu RI Medvedev, Ivan/E-8486-2014 FU NASA; NSF [0353963]; Department of Defense FX The authors thank Frank C. De Lucia for use of the FASSST spectrometer and other resources in the Microwave Laboratory at Ohio State University. This material is based upon work supported by NASA, partially supported by the NSF under Grant No. 0353963 and through funding provided by the Department of Defense. Portions of this paper present research carried out at the jet Propulsion Laboratory, California Institute of Technology, Linder contract with the National Aeronautics and Space Administration. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of NASA. NR 28 TC 4 Z9 4 U1 0 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 SEP-OCT PY 2008 VL 251 IS 1-2 BP 358 EP 364 DI 10.1016/j.jms.2008.03.025 PG 7 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA 347UY UT WOS:000259167900044 ER PT J AU Pearson, JC Brauer, CS Drouin, BJ AF Pearson, John C. Brauer, Carolyn S. Drouin, Brian J. TI The asymmetric top-asymmetric frame internal rotation spectrum of ethyl alcohol SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Review DE rotational spectrum; internal rotation; asymmetric frame; asymmetric top; ethanol; interstellar medium ID VIBRATIONAL RAMAN PROFILE; SUBMILLIMETER-WAVE SPECTRUM; DEUTERATED METHYL ALCOHOLS; ZERO-POINT ENERGY; MICROWAVE SPECTRUM; GAS-PHASE; CONFORMATIONAL-ANALYSIS; LALCOOL ETHYLIQUE; INFRARED-SPECTRA; ALPHA DEPENDENCE AB The rotational-torsional spectrum of ethyl alcohol is presented in the torsional ground state of the OH internal rotation. The spectrum has been investigated in the 12-1650 GHz range. Over 10 000 transitions with quantum numbers through J = 76 and K-a = 26 have been assigned and analyzed with a three state Hamiltonian model accounting for the predominately threefold asymmetric internal rotation of the OH group. We believe that this is the first comprehensive analysis of a predominately threefold asymmetric top-asymmetric frame internal rotation problem. The data set includes over 1000 trans to gauche transitions as well as examples of numerous torsion-rotation interactions. The general features of the spectrum are discussed along with a detailed discussion of the Hamiltonian model, its limitations and the prospects for further Hamiltonian development. A complete set of torsion-rotation constants have been determined using an effective Hamiltonian that models the spectrum with a near unity reduced deviation. The comprehensive nature of the data will make ethyl alcohol the prototypical asymmetric top-asymmetric frame internal rotation problem and facilitate the Subsequent refinement of the Hamiltonian models. (C) 2008 Elsevier Inc. All rights reserved. C1 [Pearson, John C.; Brauer, Carolyn S.; Drouin, Brian J.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Drouin, BJ (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM brian.j.drouin@jpl.nasa.gov NR 104 TC 21 Z9 21 U1 1 U2 15 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 SEP-OCT PY 2008 VL 251 IS 1-2 BP 394 EP 409 DI 10.1016/j.jms.2008.05.007 PG 16 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA 347UY UT WOS:000259167900050 ER PT J AU Park, Y Koch, L Song, KD Park, S King, G Choi, S AF Park, Yeonjoon Koch, Laura Song, Kyo D. Park, SangJoon King, Glen Choi, Sang TI Miniaturization of a Fresnel spectrometer SO JOURNAL OF OPTICS A-PURE AND APPLIED OPTICS LA English DT Article DE Fresnel diffraction; micro-spectrometer; miniaturization; zone plate and circular grating ID LIQUID-CRYSTALS; ZONE PLATES; DIFFRACTION; LENS; MICROSCOPE AB The core optical parts of an ultra-small spectrometer with less than 1 mm diameter were constructed using Fresnel diffraction. The fabricated spectrometer grating has a diameter of 750 mu m and a focal length of 2.4 mm at 533 nm wavelength. The micro-spectrometer was built with a simple negative zone plate that has an opaque center with an ecliptic shadow to remove the zero-order direct beam to the aperture slit. Unlike conventional approaches, detailed optical calculation indicates that the ideal spectral resolution and resolving power in the Fresnel regime do not depend on the miniaturized sizes but only on the total number of rings. We calculated the 2D and 3D photon distributions around the aperture slit and confirmed that improved micro-spectrometers below 1 mm in diameter can be built with Fresnel diffraction. The comparison between mathematical simulation and measured data demonstrates the theoretical resolution, measured performance, misalignment effect, and improvement for the ultra-small Fresnel spectrometer. We suggest the utilization of an array of Fresnel spectrometers for tunable multi-spectral imaging in the ultra-violet range. C1 [Park, Yeonjoon] Natl Inst Aerosp, Hampton, VA 23681 USA. [Koch, Laura; Song, Kyo D.] Norfolk State Univ, Dept Engn, Norfolk, VA 23504 USA. [Park, SangJoon] Kyungwon Univ, Dept Chem, Kyonggi Do 461701, South Korea. [King, Glen; Choi, Sang] NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Park, Y (reprint author), George Washington Univ, Dept Mech & Aerosp Engn, Washington, DC 20052 USA. FU NASA, USA [SAA15546]; KOSEF program; Ministry of Science, Technology, and Education, Republic of Korea FX The authors appreciate the assistance of Ms. Pokeun Han and Ms. Seojin Kim with the focused ion beam machine. This research was supported by the space act agreement SAA15546 of NASA, USA and KOSEF program by the Ministry of Science, Technology, and Education, Republic of Korea. NR 26 TC 8 Z9 9 U1 0 U2 6 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1464-4258 J9 J OPT A-PURE APPL OP JI J. Opt. A-Pure Appl. Opt. PD SEP PY 2008 VL 10 IS 9 AR 095301 DI 10.1088/1464-4258/10/9/095301 PG 8 WC Optics SC Optics GA 355HM UT WOS:000259700000017 ER PT J AU Laurel, BJ Hurst, TP Copeman, LA Davis, MW AF Laurel, Benjamin J. Hurst, Thomas P. Copeman, Louise A. Davis, Michael W. TI The role of temperature on the growth and survival of early and late hatching Pacific cod larvae (Gadus macrocephalus) SO JOURNAL OF PLANKTON RESEARCH LA English DT Article ID POLLOCK THERAGRA-CHALCOGRAMMA; ESCAPE RESPONSE; MALLOTUS-VILLOSUS; EGG SIZE; FISH; MORTALITY; SALINITY; TIME; EVOLUTION; ECOLOGY AB Fish larvae hatch asynchronously from egg batches despite experiencing a common environment during their development. The consequences for growth and survival of early and late hatching larvae were examined in pre-feeding Pacific cod larvae under varying temperatures (i.e. 0-8 degrees C) in the laboratory. As expected, time-to-first hatch and variation in time-to-hatch were negatively correlated with temperature. Larvae successfully hatched in the 0 degrees C treatment, but hatch rates were poorer at this temperature relative to other temperature treatments. Size-at-hatch and the maximum size achieved during the pre-feeding larval stage were highest in the 0-4 degrees C treatments, indicating that these temperatures are likely optimal for the conversion of endogenous resources to growth. At all temperatures, early hatching larvae were smaller but had more lipid reserves and survived longer after hatch in the absence of food than late hatching larvae. Together these data suggest that temperature fluctuations in the North Pacific have direct potential to impact the size, growth and endogenous reserves of Pacific cod larvae, which in turn, will likely influence survival through interactions with the prey and predator field. C1 [Laurel, Benjamin J.; Hurst, Thomas P.; Copeman, Louise A.; Davis, Michael W.] NOAA, Fisheries Behav Ecol Program, Alaska Fisheries Sci Ctr, Natl Marine Fisheries Serv,Hatfield Marine Sci Ct, Newport, OR 97365 USA. RP Laurel, BJ (reprint author), NOAA, Fisheries Behav Ecol Program, Alaska Fisheries Sci Ctr, Natl Marine Fisheries Serv,Hatfield Marine Sci Ct, Newport, OR 97365 USA. EM ben.laurel@noaa.gov RI Hurst, Thomas/N-1401-2013 FU North Pacific Research Board (NPRB) [R0605] FX This project was supported in part with funding from the North Pacific Research Board (NPRB) grant #R0605. NR 34 TC 30 Z9 33 U1 3 U2 12 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0142-7873 J9 J PLANKTON RES JI J. Plankton Res. PD SEP PY 2008 VL 30 IS 9 BP 1051 EP 1060 DI 10.1093/plankt/fbn057 PG 10 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA 349SQ UT WOS:000259304000008 ER PT J AU Williams, GJ Smith, TB Gallimore, AD AF Williams, G. J., Jr. Smith, T. B. Gallimore, A. D. TI Measurement of 30-centimeter ion thruster discharge cathode erosion SO JOURNAL OF PROPULSION AND POWER LA English DT Article ID LASER-INDUCED FLUORESCENCE AB Relative erosion rates of the discharge cathode assembly of a 30-cm ion engine are measured using laser-induced fluorescence. Molybdenum and tungsten erosion products are interrogated downstream of the discharge cathode assembly during beam extraction. Erosion of the discharge cathode assembly is characterized for both keepered and unkeepered configurations. The erosion increases with both discharge current and voltage, and spatially resolved measurements agree with observed erosion patterns. Erosion rates are calculated using data from previous wear tests. Magnitudes and trends in the rates are correlated with both previous and subsequent wear tests. Laser-induced fluorescence is demonstrated to be a technique to measure relative internal erosion rates, and a path is identified for measuring absolute rates. C1 [Williams, G. J., Jr.] Ohio Aerosp Inst, Cleveland, OH 44135 USA. [Smith, T. B.; Gallimore, A. D.] Univ Michigan, Ann Arbor, MI 48109 USA. RP Williams, GJ (reprint author), NASA, John H Glenn Res Ctr Lewis Field, Mail Stop 16-1,21000 Brookpark Rd, Cleveland, OH 44116 USA. FU NASA [NAG-31572, NAG-32216] FX This research was conducted under NASA grants NAG-31572 and NAG-32216, monitored by J. Sovey. The work was made possible by the continuing support of NASA John H. Glenn Research Center at Lewis Field (GRC) and the personnel associated with the On-Board Propulsion Branch. The functional model thruster used in this investigation, along with its power console and feed system, were provided by NASA GRC. All measurements were conducted at the Plasmadynamics and Electric Propulsion Laboratory (PEPL) at the University of Michigan. The authors would like to thank the Aerospace Engineering Department's. technicians and the other students in the PEPL for their assistance and support. NR 41 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 0748-4658 J9 J PROPUL POWER JI J. Propul. Power PD SEP-OCT PY 2008 VL 24 IS 5 BP 973 EP 980 DI 10.2514/1.22982 PG 8 WC Engineering, Aerospace SC Engineering GA 348LF UT WOS:000259211300008 ER PT J AU Le, DB Goyne, CP Krauss, RH AF Le, D. B. Goyne, C. P. Krauss, R. H. TI Shock train leading-edge detection in a dual-mode scramjet SO JOURNAL OF PROPULSION AND POWER LA English DT Article; Proceedings Paper CT AIAA 44th Aerospace Sciences Meeting and Exhibit/ASME Wind Energy Conference CY JAN 09-12, 2006 CL Reno, NV SP AIAA, ASME ID COMBUSTOR; INLETS; WAVE AB Time-resolved pressure measurements in a dual-mode scratnjet isolator were examined to investigate the potential for using the measurements for shock train leading-edge detection. Changes in the pressure magnitude, standard deviation levels, and frequency content were observed as the shock train advanced upstream past each pressure measurement station. Three detection criteria were defined and examined: 1) 150% of the normalized pressure magnitude upstream of combustion influences, 2) 150% of the normalized pressure standard deviation level upstream of combustion influences, and 3) the maximum value of the normalized pressure standard deviation. Another method of shock train leading-edge detection involved the examination of the frequency content of the pressure signal using power spectra analysis. Results indicated that the second detection criterion provided the earliest method of shock train detection as the shock train moved upstream, followed by the first and third criteria. Also, the frequency content of the pressure signals significantly changed near the shock train leading edge. However, a comparison of this method to the three criteria first examined showed that it did not provide earlier shock train detection. C1 [Le, D. B.; Goyne, C. P.; Krauss, R. H.] Univ Virginia, Charlottesville, VA 22904 USA. RP Le, DB (reprint author), NASA, Langley Res Ctr, Mail Stop 442, Hampton, VA 23602 USA. NR 16 TC 21 Z9 24 U1 0 U2 13 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 SEP-OCT PY 2008 VL 24 IS 5 BP 1035 EP 1041 DI 10.2514/1.32592 PG 7 WC Engineering, Aerospace SC Engineering GA 348LF UT WOS:000259211300015 ER PT J AU Le, DB Goyne, CP Krauss, RH McDaniel, JC AF Le, D. B. Goyne, C. P. Krauss, R. H. McDaniel, J. C. TI Experimental study of a dual-mode scramjet isolator SO JOURNAL OF PROPULSION AND POWER LA English DT Article; Proceedings Paper CT AIAA 43rd Aerospace Sciences Meeting and Exhibit CY JAN 10-13, 2005 CL Reno, NV SP AIAA ID COMBUSTOR AB A constant-area isolator was fabricated and tested in conjunction with a Mach 2 hydrogen-air combustor operating at a simulated Mach 5 flight enthalpy. Predicted isolator performance was validated through pressure measurements obtained via low-frequency pressure taps. The maximum pressure ratio measured in the combustor approached the design limit of 4.5. Scramjet operability, the range of equivalence ratios over which combustion was sustained without shock-inlet interaction, was improved to 0.06-0.32, as opposed to 0.32-0.37 without the isolator. For a given change in fuel equivalence ratio, the location of the shock train was easier to control with the isolator modification. Shock-train location repeatability was found to vary somewhat with equivalence ratio. Small fluctuations in the time-resolved pressure history indicated that the shock train was relatively temporally steady for a given equivalence ratio. High-frequency pressure measurements were within a 95% confidence interval of low-frequency pressure measurements. High-frequency results indicated that an increase in pressure and large pressure fluctuations occurred near the leading edge of the shock train. Power spectral analyses also indicated that there is significant variation in the frequency content of the pressure signal upstream and downstream of the shock-train leading edge. These results suggest that methods of shock-train leading-edge detection may be developed using pressure-time history characteristics other than the pressure magnitude. C1 [Le, D. B.; Goyne, C. P.; Krauss, R. H.; McDaniel, J. C.] Univ Virginia, Charlottesville, VA 22904 USA. RP Le, DB (reprint author), NASA, Langley Res Ctr, Mail Stop 442, Hampton, VA 23602 USA. NR 15 TC 21 Z9 25 U1 1 U2 15 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 SEP-OCT PY 2008 VL 24 IS 5 BP 1050 EP 1057 DI 10.2514/1.32591 PG 8 WC Engineering, Aerospace SC Engineering GA 348LF UT WOS:000259211300017 ER PT J AU Polzin, KA Markusic, TE Stanojev, BJ Dodson, C DeHoyos, A AF Polzin, Kurt A. Markusic, Thomas E. Stanojev, Botis J. Dodson, Chtis DeHoyos, Amado TI Electromagnetic flow sensor for liquid-metal-fed electric propulsion SO JOURNAL OF PROPULSION AND POWER LA English DT Article C1 [Polzin, Kurt A.] NASA, George C Marshall Space Flight Ctr, Prop Res & Technol Applicat Branch, Prop Syst Dept, Huntsville, AL 35812 USA. [Stanojev, Botis J.] Madison Res Corp, Huntsville, AL 35805 USA. RP Polzin, KA (reprint author), NASA, George C Marshall Space Flight Ctr, Prop Res & Technol Applicat Branch, Prop Syst Dept, Huntsville, AL 35812 USA. FU NASA's Exploration Systems Mission Directorate [NNM05AA25C] FX The authors appreciate the continued support of Jim Martin and Michael LaPointe. This work was supported by NASA's Exploration Systems Mission Directorate and performed under contract NNM05AA25C, managed by Randy Baggett. NR 17 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 0748-4658 J9 J PROPUL POWER JI J. Propul. Power PD SEP-OCT PY 2008 VL 24 IS 5 BP 1141 EP 1144 DI 10.2514/1.35329 PG 4 WC Engineering, Aerospace SC Engineering GA 348LF UT WOS:000259211300028 ER PT J AU Ottaviani, M Spurr, R Stamnes, K Li, W Su, WY Wiscombe, W AF Ottaviani, Matteo Spurr, Robert Stamnes, Knut Li, Wei Su, Wenying Wiscombe, Warren TI Improving the description of sunglint for accurate prediction of remotely sensed radiances SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article DE ocean BRDF; aerosols; atmospheric scattering; multiple reflections; shadowing ID ATMOSPHERE-OCEAN SYSTEM; AEROSOL OPTICAL-PROPERTIES; RADIATIVE-TRANSFER; COLOR IMAGERY; SUN GLINT; RETRIEVAL; SCATTERING; ALGORITHM; EQUATION; MISSION AB The bidirectional reflection distribution function (BRDF) of the ocean is a critical boundary condition for radiative transfer calculations in the coupled atmosphere-ocean system. Existing models express the extent of the glint-contaminated region and its contribution to the radiance essentially as a function of the wind speed. Art accurate treatment of the glint contribution and its propagation in the atmosphere Would Improve Current correction schemes and hence rescue a significant portion of data presently discarded as "glint contaminated". In current satellite imagery, a correction to the sensor-measured radiances is limited to the region at the edge of the glint, where the contribution is below a certain threshold. This correction assumes the sunglint radiance to be directly transmitted through the atmosphere. To quantify the error introduced by this approximation we employ a radiative transfer code that allows for a user-specified BRDF at the atmosphere-ocean interface and rigorously accounts for multiple scattering. We show that the errors incurred by ignoring multiple scattering are very significant and typically lie in the range 10-90%. Multiple reflections and shadowing at the Surface can also be accounted for, and we illustrate the importance of such processes at grazing geometries. (C) 2008 Elsevier Ltd. All rights reserved. C1 [Ottaviani, Matteo; Stamnes, Knut; Li, Wei] Stevens Inst Technol, Dept Phys & Engn Phys, Light & Life Lab, Hoboken, NJ 07030 USA. [Spurr, Robert] RT Solut Inc, Cambridge, MA 02138 USA. [Su, Wenying] Sci Syst & Applicat Inc, Hampton, VA 23666 USA. [Wiscombe, Warren] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Ottaviani, M (reprint author), Stevens Inst Technol, Dept Phys & Engn Phys, Light & Life Lab, Hoboken, NJ 07030 USA. EM mottavia@stevens.edu RI Wiscombe, Warren/D-4665-2012 OI Wiscombe, Warren/0000-0001-6844-9849 FU NASA EOS FX This work was supported by a grant from the NASA EOS program. NR 36 TC 18 Z9 18 U1 0 U2 2 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 SEP PY 2008 VL 109 IS 14 BP 2364 EP 2375 DI 10.1016/j.jqsrt.2008.05.012 PG 12 WC Optics; Spectroscopy SC Optics; Spectroscopy GA 345GS UT WOS:000258984900005 ER PT J AU Liu, L Mishchenko, MI AF Liu, Li Mishchenko, Michael I. TI Toward unified satellite climatology of aerosol properties: Direct comparisons of advanced level 2 aerosol products SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article DE tropospheric aerosols; remote sensing ID OPTICAL-THICKNESS RETRIEVALS; TROPOSPHERIC AEROSOLS; OCEAN; MODIS; MISR; SENSITIVITY; VALIDATION; ATMOSPHERE; SCATTERING; SPHEROIDS AB The development of a unified satellite climatology of aerosol properties requires accurate quantification and deep understanding Of the Underlying factors contributing to discrepancies between individual satellite products. In this paper we compare the most recent level 2 results obtained for coincident pixels viewed at essentially the same time by the Moderate Resolution Imaging Spectroradiometer (MODIS) and Multiangle Imaging Spectroradiometer (MISR) instruments flown oil the EOS Terra platform. This strategy eliminates potential sampling effects and provides a virtually direct comparison of spatially and temporally collocated MODIS and MISR retrievals. We show that the MODIS and MISR Angstrom exponent datasets reveal essentially no correlation. Although the corresponding aerosol optical thickness (AOT) datasets can agree worse than expected over the oceans, still the agreement is often satisfactory. However, the agreement over the land is often poor or even unacceptable. Of the collocated pixels for which there is a MODIS aerosol retrieval, only similar to 40% or fewer pixels have a MISR aerosol retrieval, and vice versa. These findings further illustrate the complexity of the problem of aerosol retrievals from satellite observations and indicate that the creation of a meaningful Unified MODIS-MISR aerosol climatology will be a nontrivial task. Published by Elsevier Ltd. C1 [Liu, Li; Mishchenko, Michael I.] NASA, Goddard Inst Space Studies, New York, NY 10025 USA. [Liu, Li] Columbia Univ, 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 EOS Program; NASA Glory Mission project FX We thank John Martonchik for valuable advice regarding the MISR aerosol-retrieval algorithm and datasets and Lorraine Remer for her assistance in the understanding of the MODIS aerosol product. Stimulating comments from two anonymous reviewers are also appreciated. This research was funded by the NASA Radiation Sciences Program managed by Hal Mating, by the NASA EOS Program, and by the NASA Glory Mission project. NR 39 TC 36 Z9 36 U1 0 U2 6 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 SEP PY 2008 VL 109 IS 14 BP 2376 EP 2385 DI 10.1016/j.jqsrt.2008.05.003 PG 10 WC Optics; Spectroscopy SC Optics; Spectroscopy GA 345GS UT WOS:000258984900006 ER PT J AU Mishchenko, MI AF Mishchenko, Michael I. TI Multiple scattering by particles embedded in an absorbing medium. 2. Radiative transfer equation SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article DE electromagnetic scattering; radiative transfer equation ID LIGHT-SCATTERING; SPHERICAL-PARTICLES; HOST MEDIUM; EXTINCTION AB This paper continues a systematic theoretical analysis of electromagnetic scattering by a group of arbitrarily sized, shaped, and oriented particles embedded in an absorbing, homogeneous, isotropic, and unbounded medium. The previously developed microphysical approach is used to derive the generalized form of the radiative transfer equation (RTE) applicable to a large group of sparsely, randomly, and uniformly distributed particles. The derivation of the RTE directly from the macroscopic Maxwell equations yields unambiguous and definitive analytical expressions for the participating quantities and thereby fully resolves the lasting Controversy Caused by the conflicting outcomes of several phenomenological approaches. Published by Elsevier Ltd. 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 crmim@giss.nasa.gov RI Mishchenko, Michael/D-4426-2012 FU NASA Radiation Sciences Program; NASA Glory Mission project FX The author thanks Adrian Doicu, Qiang Fu, Joop Hovenier, Michael Kahnert, Tom Rother, Cornelis van der Mee, Gorden Videen, and Ping Yang for useful discussions. This research was supported by the NASA Radiation Sciences Program managed by Hal Maring and by the NASA Glory Mission project. NR 21 TC 16 Z9 16 U1 1 U2 7 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 SEP PY 2008 VL 109 IS 14 BP 2386 EP 2390 DI 10.1016/j.jqsrt.2008.05.006 PG 5 WC Optics; Spectroscopy SC Optics; Spectroscopy GA 345GS UT WOS:000258984900007 ER PT J AU Johnston, CO Hollis, BR Sutton, K AF Johnston, Christopher O. Hollis, Brian R. Sutton, Kenneth TI Spectrum Modeling for Air Shock-Layer Radiation at Lunar-Return Conditions SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article ID ATOMIC TRANSITION-PROBABILITIES; VACUUM ULTRAVIOLET LINES; OSCILLATOR STRENGTH MEASUREMENTS; NEUTRAL NITROGEN LINES; CONTINUUM RADIATION; DIATOMIC-MOLECULES; VOIGT PROFILE; N-I; OXYGEN; PLASMA AB Anew air-radiation model is presented for the calculation of the radiative flux from lunar-return shock layers. For modeling atomic lines, the data from a variety of theoretical and experimental sources are compiled and reviewed. A line model is chosen that consists of oscillator strengths from the National Institute of Standards and Technology database and the Opacity Project (for many lines not listed by the National Institute of Standards and Technology), as well as Stark, broadening widths obtained from the average of available values. Uncertainties for the oscillator strengths and Stark broadening widths are conservatively chosen from the reviewed data, and for the oscillator strengths, the chosen uncertainties are found to be larger than those listed in the National Institute of Standards and Technology database. This new atomic line model is compared with previous models for equilibrium constant-property layers chosen to approximately represent a lunar-return shock layer. It is found that the new model increases the emission resulting from the 1-6-eV spectral range by up to 50%. This increase is due to both the increase in oscillator strengths for some important lines and to the addition of lines from the Opacity Project, which are not commonly treated in shock-layer radiation predictions. Detailed theoretical atomic bound-free cross sections obtained from the Opacity Project's TOPbase are applied for nitrogen and oxygen. An efficient method of treating these detailed cross sections is presented. The emission from negative ions is considered and shown to contribute up to 10% to the total radiative flux. The modeling of the molecular-band systems using the smeared-rotational-band approach is reviewed. The validity of the smeared-rotational-band approach for both emitting and absorbing-band systems is shown through comparisons with the computationally intensive line-by-line approach. The absorbing-band systems are shown to reduce the radiative flux by up to 10%, whereas the emitting-band systems are shown to contribute less than a 5% increase in the flux. The combined models chosen for the atomic line, atomic bound-free, negative-ion, and molecular-band components result in a computationally efficient model that is ideal for coupled solutions with a Navier-Stokes flowfield. It is recommended that the notable increases shown, relative to previous models, for the atomic line and negative-ion continuum should be included in future radiation predictions for lunar-return vehicles. 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 85 TC 33 Z9 33 U1 0 U2 5 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 SEP-OCT PY 2008 VL 45 IS 5 BP 865 EP 878 DI 10.2514/1.33004 PG 14 WC Engineering, Aerospace SC Engineering GA 363NP UT WOS:000260274300001 ER PT J AU Johnston, CO Hollis, BR Sutton, K AF Johnston, Christopher O. Hollis, Brian R. Sutton, Kenneth TI Non-Boltzmann Modeling for Air Shock-Layer Radiation at Lunar-Return Conditions SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article ID ELECTRON-IMPACT EXCITATION; CROSS-SECTIONS; ATOMIC OXYGEN; COLLISIONAL EXCITATION; RATE COEFFICIENTS; IONIZED NITROGEN; LINE-INTENSITIES; HIGH-TEMPERATURE; NEUTRAL OXYGEN; HEAT-TRANSFER AB This paper investigates the non-Boltzmann modeling of the radiating atomic and molecular electronic states present in lunar-return shock layers. The master equation is derived for a general atom or molecule while accounting for a variety of excitation and deexcitation mechanisms. A new set of electronic-impact excitation rates is compiled for N, O, and N-2(+), which are the main radiating species for most lunar-return shock layers. Based on these new rates, a novel approach of curve-fitting the non-Boltzmann populations of the radiating atomic and molecular states is developed. This new approach provides a simple and accurate method for calculating the atomic and molecular non-Boltzmann populations while avoiding the matrix inversion procedure required for the detailed solution of the master equation. The radiative-flux values predicted by the present detailed non-Boltzmann model and the approximate curve-fitting approach are shown to agree within 5% for the Fire II 1634-s case. 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 46 TC 25 Z9 25 U1 0 U2 0 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 SEP-OCT PY 2008 VL 45 IS 5 BP 879 EP 890 DI 10.2514/1.33006 PG 12 WC Engineering, Aerospace SC Engineering GA 363NP UT WOS:000260274300002 ER PT J AU Finkbeiner, JR Dunlap, PH Steinetz, BM Daniels, CC AF Finkbeiner, Joshua R. Dunlap, Patrick H., Jr. Steinetz, Bruce M. Daniels, Christopher C. TI Review of Seal Designs on the Apollo Spacecraft SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article ID MODULE AB The Apollo spacecraft required a variety of seal designs to support human spaceflight to the moon and to return the crews safely to Earth. High-temperature seals were required for gaps in the thermal protection system to protect the underlying structures from the high heating environment of superorbital reentry. Reliable pressure seals were also required to prevent the loss of habitable atmosphere during missions to the moon. A review is presented of some of the seals used on the Apollo spacecraft, including the seal in the gap between the heat shield and back shell and seals for penetrations through the heat shield, docking hatches, windows, and the capsule pressure hull. A brief discussion of seal requirements for the Orion spacecraft is also presented. C1 [Finkbeiner, Joshua R.; Dunlap, Patrick H., Jr.; Steinetz, Bruce M.] NASA, John H Glenn Res Ctr Lewis Field, Mat & Struct Div, Cleveland, OH 44135 USA. [Daniels, Christopher C.] Univ Akron, Coll Engn, Akron, OH 44325 USA. RP Finkbeiner, JR (reprint author), NASA, John H Glenn Res Ctr Lewis Field, Mat & Struct Div, 21000 Brookpk Road, Cleveland, OH 44135 USA. NR 25 TC 5 Z9 6 U1 0 U2 7 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 SEP-OCT PY 2008 VL 45 IS 5 BP 900 EP 910 DI 10.2514/1.27188 PG 11 WC Engineering, Aerospace SC Engineering GA 363NP UT WOS:000260274300004 ER PT J AU Edwards, JW Keller, DF Schuster, DM Piatak, DJ Rausch, RD Bartels, RE Ivanco, TG AF Edwards, John W. Keller, Donald F. Schuster, David M. Piatak, David J. Rausch, Russ D. Bartels, Robert E. Ivanco, Thomas G. TI Aeroelastic Response and Protection of Space Shuttle External Tank Cable Trays SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article; Proceedings Paper CT AIAA/ASME/SAE/ASEE 41st Joint Propulsion Conference CY JUL 10-13, 2005 CL Tucson, AZ SP AIAA, ASME, SAE, ASEE AB Sections of the space shuttle external tank liquid oxygen and liquid hydrogen cable trays are shielded from potentially damaging air loads with foam protuberance aerodynamic load ramps. Flight standard design liquid oxygen and liquid hydrogen cable tray sections were tested with and without protuberance aerodynamic load ramp models in the United States Air Force Arnold Engineering Development Center's 16T transonic wind tunnel to obtain experimental data on the aeroelastic stability and response characteristics of the trays and as part of the larger effort to determine whether the protuberance aerodynamic load ramps can be safely modified or removed. Computational fluid dynamic simulations of the full-stack shuttle launch configuration were used to investigate the flow characteristics around and under the cable trays without the protective protuberance aerodynamic load ramps and to define maximum crossflow Mach numbers and dynamic pressures experienced during launch. These crossflow conditions were used to establish wind-tunnel test conditions, which also included conservative margins. For all of the conditions and configurations tested, no aeroelastic instabilities or unacceptable dynamic response levels were encountered and no visible structural damage was experienced by any of the tested cable tray sections. Based upon this aeroelastic characterization test, three potentially acceptable alternatives are available for the liquid oxygen cable tray protuberance aerodynamic load ramps: miniramps, tray fences, or no ramps. All configurations were tested to maximum conditions, except the liquid hydrogen trays at -15 deg crossflow angle. This exception is the only caveat preventing the proposal of acceptable alternative configurations for the liquid hydrogen trays as well. Structural assessment of all tray loads and tray response measurements from launches following the shuttle return-to-flight with the existing protuberance aerodynamic load ramps will determine the acceptability of these protuberance aerodynamic load ramp alternatives. C1 [Edwards, John W.; Keller, Donald F.; Schuster, David M.; Piatak, David J.; Rausch, Russ D.; Bartels, Robert E.; Ivanco, Thomas G.] 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 3 TC 0 Z9 0 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 SEP-OCT PY 2008 VL 45 IS 5 BP 988 EP 998 DI 10.2514/1.30077 PG 11 WC Engineering, Aerospace SC Engineering GA 363NP UT WOS:000260274300013 ER PT J AU Fasanella, EL Jackson, KE Lyle, KH Jones, LE Hardy, RC Kellas, S Carney, KS Melis, ME AF Fasanella, Edwin L. Jackson, Karen E. Lyle, Karen H. Jones, Lisa E. Hardy, Robin C. Kellas, Sotiris Carney, Kelly S. Melis, Matthew E. TI Dynamic Impact Tolerance of Space Shuttle Orbiter Wing Leading-Edge Panels SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article; Proceedings Paper CT AIAA Jet Propulsion Conference CY JUL 10-13, 2007 CL Tucson, AZ SP AIAA AB This paper describes a research program conducted to enable accurate prediction of the impact tolerance of the shuttle Orbiter leading-edge wing panels using physics-based codes such as LS-DYNA, a nonlinear explicit transient dynamic finite element code. The shuttle leading-edge panels are constructed of reinforced carbon-carbon composite material, which is used because of its thermal properties to protect the shuttle during reentry into the Earth's atmosphere. Accurate predictions of impact damage from insulating foam and other debris strikes that occur during launch require materials characterization of expected debris, including strain-rate effects. First, analytical models of individual foam and reinforced carbon-carbon materials were validated. Next, analytical models of foam cylinders impacting 6 x 6 in. reinforced carbon-carbon flat plates were developed and validated. LS-DYNA pretest models of the reinforced carbon-carbon flat-plate specimens established the impact velocity of the test for three damage levels: no detectable damage, nondestructive-evaluation-detectable damage, or visible damage such as a through-the-thickness crack or hole. Finally, the threshold of impact damage for reinforced carbon-carbon on representative Orbiter wing panels was predicted for both a small through-the-thickness crack and for nondestructive-evaluation-detectable damage. C1 [Fasanella, Edwin L.; Jackson, Karen E.; Lyle, Karen H.; Jones, Lisa E.; Hardy, Robin C.; Kellas, Sotiris] NASA, Langley Res Ctr, Struct Dynam Branch, Hampton, VA 23681 USA. [Carney, Kelly S.; Melis, Matthew E.] NASA, John H Glenn Res Ctr Lewis Field, Struct Mech & Dynam Branch, Cleveland, OH 44135 USA. RP Fasanella, EL (reprint author), NASA, Langley Res Ctr, Struct Dynam Branch, Hampton, VA 23681 USA. NR 12 TC 1 Z9 1 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 SEP-OCT PY 2008 VL 45 IS 5 BP 1042 EP 1052 DI 10.2514/1.31373 PG 11 WC Engineering, Aerospace SC Engineering GA 363NP UT WOS:000260274300018 ER PT J AU Wu, KC Cruz, JN Antol, J Sasamoto, WA AF Wu, K. Chauncey Cruz, Jonathan N. Antol, Jeffrey Sasamoto, Washito A. TI Systems Analysis and Structural Design of an Unpressurized Cargo Delivery Vehicle SO JOURNAL OF SPACECRAFT AND ROCKETS 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 AB The International Space Station will require a continuous supply of replacement parts for ongoing maintenance and repair after the planned retirement of the space shuttle in 2010. These parts are existing line-replaceable items collectively called orbital replacement units, and include heavy and oversized items such as control moment gyroscopes and stowed radiator arrays originally intended for delivery aboard the space shuttle. Current resupply spacecraft have limited to no capability to deliver these external logistics. In support of NASA's Exploration Systems Architecture Study, a team at Langley Research Center designed an unpressurized cargo delivery vehicle to deliver bulk cargo to the space station. This vehicle was required to deliver at least 13,200 lb of cargo mounted on at least 18 flight releasable attachment mechanisms. The crew launch vehicle design recommended in the Exploration Systems Architecture Study would be used to launch one annual resupply flight to the International Space Station. The baseline vehicle design has a cargo capacity of 16,000 lb mounted on up to 20 flight releasable attachment mechanisms. Major vehicle components are an 18.0 ft-diam cargo module containing two detachable pallets with the payload, a service module to provide propulsion and power, and a jettisonable nose cone. To reduce cost and risk, the service module is identical to the one used for the crew exploration vehicle design. C1 [Wu, K. Chauncey] NASA, Langley Res Ctr, Struct Mech & Concepts Branch, Res & Technol Directorate, Hampton, VA 23681 USA. [Cruz, Jonathan N.] NASA, Langley Res Ctr, Syst Engn & Integrat Off, Syst Engn Directorate, Hampton, VA 23681 USA. [Antol, Jeffrey; Sasamoto, Washito A.] NASA, Langley Res Ctr, Space Miss Anal Branch, Syst Anal & Concepts Directorate, Hampton, VA 23681 USA. RP Wu, KC (reprint author), NASA, Langley Res Ctr, Struct Mech & Concepts Branch, Res & Technol Directorate, Mail Stop 190, Hampton, VA 23681 USA. NR 9 TC 0 Z9 0 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 SEP-OCT PY 2008 VL 45 IS 5 BP 1061 EP 1069 DI 10.2514/1.32661 PG 9 WC Engineering, Aerospace SC Engineering GA 363NP UT WOS:000260274300020 ER PT J AU Sehirlioglu, A Sayir, A Dynys, F AF Sehirlioglu, Alp Sayir, Ali Dynys, Fred TI Microstructure-property relationships in liquid phase-sintered high-temperature bismuth scandium oxide-lead titanate piezoceramics SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article; Proceedings Paper CT Materials Science and Technology Conference and Exhibition (MS&T'07) CY SEP 16-20, 2007 CL Detroit, MI ID HIGH CURIE-TEMPERATURE; SINGLE-CRYSTALS; PIEZOELECTRIC PROPERTIES; ELECTRICAL-PROPERTIES; PEROVSKITE SYSTEM; SOLID-SOLUTION; CERAMICS; (1-X)BISCO3-XPBTIO(3); BOUNDARY; CONDUCTIVITY AB High-temperature piezoelectrics are necessary for aeronautic and aerospace applications. The principal challenge for the insertion of piezoelectric materials is their limitation for upper use temperature, which is due to low Curie temperature and increasing conductivity at high temperatures. We investigated processing, microstructure, and property relationships of (1-x)BiScO3-(x)PbTiO3 composition as a promising high-temperature piezoelectric. The effects of excess PbO and Bi2O3 and their partitioning in grain boundaries were studied using impedance spectroscopy, ferroelectric, and piezoelectric measurement techniques. Excess Pb addition increased the grain-boundary conduction and the grain-boundary area resulting in ceramics with higher AC-conductivity (tan delta = 0.9 and 1.7 for 0 and 5 at.% excess Pb at 350 degrees C and at 10 kHz) that were not resistive enough to pole. Excess Bi addition increased the resistivity (tan delta = 0.9 and 0.1 for 0 and 5 at.% excess Pb at 350 degrees C and at 10 kHz), improved poling, and increased the piezoelectric coefficient from 354 to 408 pC/N for 5 at.% excess Bi addition. Thus, excess Bi2O3 proved to be a successful liquid phase forming additive to improve the 0.37BiScO(3)-0.63PbTiO(3) piezoceramics for high-temperature applications, as a result of increased resistivity and enhanced piezoelectric activity. C1 [Sehirlioglu, Alp; Sayir, Ali; Dynys, Fred] NASA John Glenn Res Ctr, Cleveland, OH 44135 USA. [Sehirlioglu, Alp; Sayir, Ali] Case Western Reserve Univ, Dept Mat Sci & Engn, Cleveland, OH 44106 USA. RP Sehirlioglu, A (reprint author), NASA John Glenn Res Ctr, Cleveland, OH 44135 USA. EM alp.sehirlioglu@case.edu NR 29 TC 23 Z9 23 U1 1 U2 13 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0002-7820 EI 1551-2916 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD SEP PY 2008 VL 91 IS 9 BP 2910 EP 2916 DI 10.1111/j.1551-2916.2008.02555.x PG 7 WC Materials Science, Ceramics SC Materials Science GA 347ON UT WOS:000259151000020 ER PT J AU Markowicz, KM Flatau, PJ Remiszewska, J Witek, M Reid, EA Reid, JS Bucholtz, A Holben, B AF Markowicz, K. M. Flatau, P. J. Remiszewska, J. Witek, M. Reid, E. A. Reid, J. S. Bucholtz, A. Holben, B. TI Observations and modeling of the surface aerosol radiative forcing during UAE(2) SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID VAPOR COLUMN ABUNDANCE; KUWAIT OIL FIRES; WATER-VAPOR; OPTICAL-PROPERTIES; AIRBORNE MEASUREMENTS; MULTIPLE-SCATTERING; LIDAR MEASUREMENTS; BOUNDARY-LAYER; DUST AEROSOLS; PERSIAN-GULF AB Aerosol radiative forcing in the Persian Gulf region is derived from data collected during the United Arab Emirates (UAE) Unified Aerosol Experiment (UAE(2)). This campaign took place in August and September of 2004. The land -sea-breeze circulation modulates the diurnal variability of the aerosol properties and aerosol radiative forcing at the surface. Larger aerosol radiative forcing is observed during the land breeze in comparison to the sea breeze. The aerosol optical properties change as the onshore wind brings slightly cleaner air. The mean diurnal value of the surface aerosol forcing during the UAE2 campaign is about -20 W m(-2), which corresponds to large aerosol optical thickness (0.45 at 500 nm). The aerosol forcing efficiency [i. e., broadband shortwave forcing per unit optical depth at 550 nm, W m(-2) (tau(500))(-1)] is -53 W m(-2) (tau(500))(-1) and the average single scattering albedo is 0.93 at 550 nm. C1 [Markowicz, K. M.; Witek, M.] Univ Warsaw, Inst Geophys, PL-02093 Warsaw, Poland. [Flatau, P. J.] Univ Calif San Diego, Scripps Inst Oceanog, La Jolla, CA 92093 USA. [Remiszewska, J.] Polish Acad Sci, Inst Geophys, Warsaw 42, Poland. [Reid, E. A.; Reid, J. S.; Bucholtz, A.] USN, Marine Meteorol Div, Res Lab, Monterey, CA USA. [Holben, B.] NASA, Goddard Space Flight Ctr, Biospher Sci Branch, Greenbelt, MD 20771 USA. RP Markowicz, KM (reprint author), Univ Warsaw, Inst Geophys, Pasteura 7, PL-02093 Warsaw, Poland. EM kmark@uninet.com.pl RI Reid, Jeffrey/B-7633-2014; Flatau, Piotr/E-2219-2011; Witek, Marcin/G-9440-2016 OI Reid, Jeffrey/0000-0002-5147-7955; NR 65 TC 10 Z9 11 U1 0 U2 7 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 SEP PY 2008 VL 65 IS 9 BP 2877 EP 2891 DI 10.1175/2007JAS2555.1 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 350UO UT WOS:000259378800007 ER PT J AU Ounaies, Z Park, C Harrison, J Lillehei, P AF Ounaies, Zoubeida Park, Cheol Harrison, Joycelyn Lillehei, Peter TI Evidence of piezoelectricity in SWNT-polyimide and SWNT-PZT-polyimide composites SO JOURNAL OF THERMOPLASTIC COMPOSITE MATERIALS LA English DT Article DE piezoelectric polyimide; single-wall carbon nanotube; lead zirconate titanate; nanocomposite ID NANOTUBE-POLYMER COMPOSITES; ELECTRICAL-PROPERTIES; CARBON NANOTUBES; CONNECTIVITY; DISPERSION AB Nanotechnology offers opportunities to reenergize the area of smart materials by addressing their current shortfalls and expanding their application range. For example, sensors based on polymer nanocomposites would provide a new paradigm for lightweight structural health monitoring for broad aeronautics and space applications. Deployable structures such as inflatable antennae and space mirrors will benefit from the incorporation of multifunctional lenses employing smart, articulating materials. In this paper, an approach to enhance the piezoelectricity of polyimides through the addition of lead zirconate titanate (PZT) particles and single-wall carbon nanotubes (SWNT) is presented. The dielectric and electrical properties of the composites are investigated as a function of SWNT volume content. The dynamic and static mechanical properties are presented to assess the effect of the inclusions on the macro-scale properties of the nanocomposites. It is found that the SWNTs increase the dielectric, piezoelectric, and mechanical properties of the polyimide matrix. Addition of the SWNT in the PZT/polyimide composites facilitates poling and results in an increase of the piezoelectric properties of the three-phase composite. C1 [Ounaies, Zoubeida] Texas A&M Univ, Coll Stn, College Stn, TX 77843 USA. [Park, Cheol] Natl Inst Aerosp, Hampton, VA 23681 USA. [Harrison, Joycelyn; Lillehei, Peter] NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Ounaies, Z (reprint author), Texas A&M Univ, Coll Stn, College Stn, TX 77843 USA. EM zounaies@tamu.edu RI Lillehei, Peter/C-9196-2009 OI Lillehei, Peter/0000-0001-8183-9980 FU NASA [NCC1-02013]; NASA University Research, Engineering and Technology Institute on Bio Inspired Materials (BIMat) [NCC-1-02037] FX The authors acknowledge David Callahan for writing Labview programs to facilitate data gathering. Z.O. research is supported in part by NASA Grant no. NCC1-02013. Z.O. appreciate support from the NASA University Research, Engineering and Technology Institute on Bio Inspired Materials (BIMat) under award no. NCC-1-02037. Finally, the authors wish to thank Dr. Ricardo Perez for his helpful comments on the manuscript. NR 33 TC 13 Z9 13 U1 2 U2 16 PU SAGE PUBLICATIONS LTD PI LONDON PA 1 OLIVERS YARD, 55 CITY ROAD, LONDON EC1Y 1SP, ENGLAND SN 0892-7057 J9 J THERMOPLAST COMPOS JI J. Thermoplast. Compos. Mater. PD SEP PY 2008 VL 21 IS 5 BP 393 EP 409 DI 10.1177/0892705708089483 PG 17 WC Materials Science, Composites SC Materials Science GA 348QV UT WOS:000259225900002 ER PT J AU Adams, JL Hartley, TT Lorenzo, CF AF Adams, J. L. Hartley, T. T. Lorenzo, C. F. TI Identification of complex order-distributions SO JOURNAL OF VIBRATION AND CONTROL LA English DT Article; Proceedings Paper CT 2nd Workshop on Fractional Differentiation and Its Applications (FDA ' 06) CY JUL 19-21, 2006 CL Oporto, PORTUGAL SP IFAC DE fractional calculus; fractional-order systems; complex order-distributions; system identification AB This article discusses the identification of fractional systems using the concepts of complex order distribution. Based on the ability to define systems using complex order-distributions, it is shown that system identification in the frequency domain using a least-squares approach can be performed. A mesh is created to cover an area in the complex-order plane. The weighting of each block in the order-plane is selected to minimize the square-error between the frequency response of the system and the identified system. The identified systems have real time responses. Four examples, including both pure real-order systems and pure complex-order systems, are presented to demonstrate the utility of the identification method. C1 [Adams, J. L.; Hartley, T. T.] Univ Akron, Dept Elect & Comp Engn, Akron, OH 44325 USA. [Lorenzo, C. F.] NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Adams, JL (reprint author), Univ Akron, Dept Elect & Comp Engn, Akron, OH 44325 USA. EM jla36@uakron.edu NR 10 TC 12 Z9 12 U1 0 U2 1 PU SAGE PUBLICATIONS LTD PI LONDON PA 1 OLIVERS YARD, 55 CITY ROAD, LONDON EC1Y 1SP, ENGLAND SN 1077-5463 J9 J VIB CONTROL JI J. Vib. Control PD SEP PY 2008 VL 14 IS 9-10 BP 1375 EP 1388 DI 10.1177/1077546307087443 PG 14 WC Acoustics; Engineering, Mechanical; Mechanics SC Acoustics; Engineering; Mechanics GA 354EV UT WOS:000259622600010 ER PT J AU Buccello-Stout, RR Bloomberg, JJ Cohen, HS Whorton, EB Weaver, GD Cromwell, RL AF Buccello-Stout, Regina R. Bloomberg, Jacob J. Cohen, Helen S. Whorton, Elbert B. Weaver, Gayle D. Cromwell, Ronita L. TI Effects of sensorimotor adaptation training on functional mobility in older adults SO JOURNALS OF GERONTOLOGY SERIES B-PSYCHOLOGICAL SCIENCES AND SOCIAL SCIENCES LA English DT Article DE functional mobility; perceptual-motor mismatch; sensorimotor adaptation ID VISUO-MOTOR PLASTICITY; VIRTUAL ENVIRONMENT; RISK-FACTORS; FALLS; PEOPLE; LOCOMOTION; RETENTION; REALITY; GAIT; INTERFERENCE AB The goal of this study was to determine if prolonged exposure to perceptual-motor mismatch increased adaptability and retention of balance in older adults. Sixteen adults, aged 66 to 81 years, were randomized to one of two groups: either the control group (n = 8) or the experimental group (n = 8). Both groups first completed six trials of walking an obstacle course. Participants then trained twice a week for 4 weeks. In the training, the control group walked on a treadmill for 20 minutes while viewing a static visual scene and the experimental group walked on a treadmill for 20 minutes while viewing a rotating visual scene that provided a perceptual-motor mismatch. Following training, both groups were post-tested on the obstacle course. The experimental group moved faster through the obstacle course with fewer penalties. This training effect was retained for 4 weeks. Exposure to perceptual-motor mismatch induced an adaptive training effect that improved balance and locomotor control in older adults. C1 [Buccello-Stout, Regina R.] NASA, Univ Space Res Assoc, Lyndon B Johnson Space Ctr, Div Flight Analogs, Houston, TX 77058 USA. [Bloomberg, Jacob J.] NASA, Lyndon B Johnson Space Ctr, Neurosci Labs, Houston, TX 77058 USA. [Cohen, Helen S.] Baylor Coll Med, Bobby R Alford Dept Otolaryngol Head & Neck Surg, Houston, TX 77030 USA. [Whorton, Elbert B.] Univ Texas Med Branch, Dept Biostat, Galveston, TX USA. [Weaver, Gayle D.] Univ Texas Med Branch, Div Rehabil Sci, Galveston, TX USA. RP Buccello-Stout, RR (reprint author), NASA, Univ Space Res Assoc, Lyndon B Johnson Space Ctr, Div Flight Analogs, 2101 NASA Pkwy,Mail Code SK37, Houston, TX 77058 USA. EM regina.buccel-lo-stout-1@nasa.gov FU National Aeronautics and Space Administration Graduate Student Researchers Program [NASA-NNJ05JG67H]; National Space Biomedical Research Institute [NASA NCC 9-58] FX This research was supported by the National Aeronautics and Space Administration Graduate Student Researchers Program under Grant NASA-NNJ05JG67H and by the National Space Biomedical Research Institute under Grant NASA NCC 9-58. The study was conducted in partial fulfillment of the requirements for Regina Bucccllo-Stout's doctoral degree at the University of Texas Medical Branch. NR 36 TC 5 Z9 5 U1 0 U2 2 PU GERONTOLOGICAL SOC AMER PI WASHINGTON PA 1030 15TH ST NW, STE 250, WASHINGTON, DC 20005202-842 USA SN 1079-5014 J9 J GERONTOL B-PSYCHOL JI J. Gerontol. Ser. B-Psychol. Sci. Soc. Sci. PD SEP PY 2008 VL 63 IS 5 BP P295 EP P300 PG 6 WC Geriatrics & Gerontology; Gerontology; Psychology; Psychology, Multidisciplinary SC Geriatrics & Gerontology; Psychology GA 352SH UT WOS:000259517200005 PM 18818444 ER PT J AU Chao, Y Li, ZJ Farrara, JD Moline, MA Schofield, OME Majumdar, SJ AF Chao, Yi Li, Zhijin Farrara, John D. Moline, Mark A. Schofield, Oscar M. E. Majumdar, Sharanya J. TI Synergistic applications of autonomous underwater vehicles and regional ocean modeling system in coastal ocean forecasting SO LIMNOLOGY AND OCEANOGRAPHY LA English DT Article ID TRANSFORM KALMAN FILTER; MONTEREY BAY; EXPLICIT; SURFACE AB The potential for using synergistic combinations of measurements from autonomous underwater vehicles (AUVs) and output from three-dimensional numerical models for studying the central California coastal region is demonstrated. Two case studies are used to illustrate the approach. In the first, propeller-driven AUV observations revealed a subsurface salinity minimum in northern Monterey Bay. A Regional Ocean Modeling System (ROMS) reanalysis of the three-dimensional flow in the region suggested an offshore source for this water and particular propagation pathways from the south and west into the bay. In the second case study, the effectiveness of assimilating observations in improving the ROMS reanalysis fields is investigated. A significant improvement, especially in the salinity fields, is demonstrated through a single glider deployed outside the intensive observational domain. These results suggest that investigation of more sophisticated techniques for using data and models together is warranted. Such techniques include increasing model resolution in areas of interest identified by observing platforms and using model-based "targeted observing'' techniques to identify areas of uncertainty in the flow to guide placement of observational assets. C1 [Chao, Yi; Li, Zhijin; Farrara, John D.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Farrara, John D.] Raytheon Informat Solut, Pasadena, CA 91101 USA. [Moline, Mark A.] Calif Polytech State Univ San Luis Obispo, Dept Biol Sci, San Luis Obispo, CA 93407 USA. [Moline, Mark A.] Calif Polytech State Univ San Luis Obispo, Ctr Coastal Marine Sci, San Luis Obispo, CA 93407 USA. [Schofield, Oscar M. E.] Rutgers State Univ, Inst Marine & Coastal Sci, New Brunswick, NJ 08903 USA. [Schofield, Oscar M. E.] Rutgers State Univ, Coastal Ocean Observat Lab, New Brunswick, NJ 08903 USA. [Majumdar, Sharanya J.] Univ Miami, RSMAS Div Meteorol & Phys Oceanog, Miami, FL 33149 USA. RP Chao, Y (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Yi.Chao@jpl.nasa.gov NR 25 TC 19 Z9 19 U1 0 U2 5 PU AMER SOC LIMNOLOGY OCEANOGRAPHY PI WACO PA 5400 BOSQUE BLVD, STE 680, WACO, TX 76710-4446 USA SN 0024-3590 J9 LIMNOL OCEANOGR JI Limnol. Oceanogr. PD SEP PY 2008 VL 53 IS 5 BP 2251 EP 2263 DI 10.4319/lo.2008.53.5_part_2.2251 PN 2 PG 13 WC Limnology; Oceanography SC Marine & Freshwater Biology; Oceanography GA 378WN UT WOS:000261355400015 ER PT J AU Forrest, AL Laval, BE Pieters, R Lim, DSS AF Forrest, Alexander L. Laval, Bernard E. Pieters, Roger Lim, Darlene S. S. TI Convectively driven transport in temperate lakes SO LIMNOLOGY AND OCEANOGRAPHY LA English DT Article ID ICE-COVERED LAKES; AUTONOMOUS UNDERWATER VEHICLE; NATURAL-CONVECTION; DENSITY CURRENTS; MIXED-LAYER; WATER; CIRCULATION; RESERVOIR; REGION; WINTER AB Penetrative convection in the surface layer of a midsize temperate lake (5 km(2)) was investigated in both summer and winter using a conductivity-temperature-depth (CTD) logger mounted on an autonomous underwater vehicle (AUV) flown repeatedly along horizontal transects at selected depths. In summer, the epilimnion cooled differentially during a calm evening (240 and 297 W m(-2) on the east and west sides of the lake, respectively). These cooling rates agree well with the average net heat flux of 270 W m(-2) estimated from meteorological data. Density currents were driven by this differential cooling. In winter, CTD profiles during a sunny day showed four distinct thermal layers beneath the ice (similar to 50 cm thick), consistent with radiative penetrative convection: a stratified diffusive layer just beneath the ice (top 1.6 m); a well-mixed convective layer (that deepens at 1.14 m d(-1) and warms at 0.015 degrees C d(-1) during the observation period); an entrainment layer (1.5 m thick); and a weakly stratified quiescent layer (to bottom). AUV transects, flown at constant depths in each layer, revealed a 150-m wide region displaying evidence of penetrative convection, surrounded by regions with negligible heat changes. These high-resolution, horizontal CTD measurements provided insight into previously unresolved physical dynamics of the well-mixed layer of a temperate lake in quasi-shear-free conditions that would have been difficult to quantify during summer months and impossible under winter ice cover without the use of an AUV platform. C1 [Forrest, Alexander L.; Laval, Bernard E.] Univ British Columbia, Dept Civil Engn, Vancouver, BC V6T 1Z4, Canada. [Pieters, Roger] Univ British Columbia, Dept Earth & Ocean Sci, Vancouver, BC V6T 1Z4, Canada. [Lim, Darlene S. S.] NASA, Ames Res Ctr, Space Sci & Astrobiol Div, Moffett Field, CA 94035 USA. RP Forrest, AL (reprint author), Univ British Columbia, Dept Civil Engn, 6250 Appl Sci Lane,Room 2010, Vancouver, BC V6T 1Z4, Canada. RI Laval, Bernard/J-9861-2012; Forrest, Alexander/C-3765-2014 OI Forrest, Alexander/0000-0002-7853-9765 FU Canadian Space Agency Canadian analogue research network (CARN) program; National Aeronautics and Space Administration (NASA) astrobiology program; National Geographic Society committee for research exploration (CRE); Canadian National Science and Engineering Research Council (NSERC); Canadian Foundation for Innovation; British Columbia Knowledge Development Fund; University of British Columbia; Canada NSERC postgraduate scholarship-doctorate (PGS-D) scholarship FX The Pavilion Lake Research Project and University of British Columbia (UBC) Gavia operations at Pavilion Lake were supported by the Canadian Space Agency Canadian analogue research network (CARN) program, the National Aeronautics and Space Administration (NASA) astrobiology program, the National Geographic Society committee for research exploration (CRE), and the Canadian National Science and Engineering Research Council (NSERC) discovery program. Funding for the purchase of UBC Gavia was provided by the Canadian Foundation for Innovation, the British Columbia Knowledge Development Fund, and the University of British Columbia. Operations at Pavilion Lake would not be possible without the support of the Ts'kw'aylaxw First Nation, the Pavilion Lake Community, Mickey and Linda Macri, Donnie Reid, Dale Andersen, Harry Bohm, and British Columbia Parks. Alexander Forrest was supported by a Canada NSERC postgraduate scholarship-doctorate (PGS-D) scholarship. We also acknowledge the technical support of Richard Yeo and Eggert Magnusson of Hafmynd, Ltd., Iceland and Martin Doble from the University of Cambridge, UK who worked hard to ensure that our under-ice endeavors were successful. This manuscript represents Pavilion Lake Research Project publication 07-01. NR 41 TC 24 Z9 24 U1 1 U2 10 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0024-3590 EI 1939-5590 J9 LIMNOL OCEANOGR JI Limnol. Oceanogr. PD SEP PY 2008 VL 53 IS 5 BP 2321 EP 2332 DI 10.4319/lo.2008.53.5_part_2.2321 PN 2 PG 12 WC Limnology; Oceanography SC Marine & Freshwater Biology; Oceanography GA 378WN UT WOS:000261355400020 ER PT J AU Abdul-Aziz, A Abumeri, G Garg, M Young, PG AF Abdul-Aziz, Ali Abumeri, G. Garg, Mohit Young, P. G. TI Structural testing of a nickel based superalloy metal foam via NDT and finite element analysis SO MATERIALS EVALUATION LA English DT Article DE metal foam; finite element; computed tomography; progressive failure analysis; NDT; 3D image AB Cellular materials are known to be useful in the application of designing light but stiff structures. This applies to components such as rotorcraft blades, car bodies or pot-table electronic devices. Structural application of the metal foam is typically confined to lightweight sandwich panels, made tip of thin, solid face sheets and a metallic foam core The resulting high-stiffness structure is lighter than that constructed only out of the solid metal material. The face sheets carry the applied in-plane and bending loads, and the role of the foam core is to separate the face sheets to carry some of the shear stresses, while remaining integral with the face sheet. Many challenges relating to the fabrication and testing of these metal foam panels continue to exist due to some mechanical properties falling short of their theoretical potential. In this study a detailed three-dimensional foam structure is generated using a series of two-dimensional computed tomography scans on metal foam. A series of the 2D images were utilized to construct a high precision solid model including all the fine details within the metal foam as detected by the computed tomography scanning. Subsequently, a finite element analysis was performed on an as-fabricated metal foam microstructure to test the foam's structural durability and behavior under tensile and compressive loading conditions. The analysis includes a progressive failure analysis using specialized code to further assess the damage initiation, propagation and failure. The open cell metal foam material is a cobalt-nickel-chromium-tungsten alloy (UNS R30605) that combines excellent high-temperature strength with good resistance to oxidizing environments tip to 1255 K for prolonged exposures. The foam is formed by a powder metallurgy process with approximately 40 pores per square centimeter. C1 [Abdul-Aziz, Ali] Cleveland State Univ, NASA Glenn Res Ctr, Dept Civil Engn, Cleveland, OH 44135 USA. [Abumeri, G.; Garg, Mohit] AlphaStar Corp, Long Beach, CA 90804 USA. [Young, P. G.] Univ Exeter, Sch Engn & Comp Sci, Exeter EX4 4QF, Devon, England. RP Abdul-Aziz, A (reprint author), Cleveland State Univ, NASA Glenn Res Ctr, Dept Civil Engn, 21000 Brook Pk Rd,MS 6-1, Cleveland, OH 44135 USA. EM ali.abdul-aziz-1@nasa.gov NR 11 TC 1 Z9 1 U1 0 U2 1 PU AMER SOC NONDESTRUCTIVE TEST PI COLUMBUS PA 1711 ARLINGATE LANE PO BOX 28518, COLUMBUS, OH 43228-0518 USA SN 0025-5327 J9 MATER EVAL JI Mater. Eval. PD SEP PY 2008 VL 66 IS 9 BP 949 EP 954 PG 6 WC Materials Science, Characterization & Testing SC Materials Science GA 346FP UT WOS:000259054400006 ER PT J AU Venkatachari, BS Cheng, GC Soni, BK Chang, SC AF Venkatachari, Balaji Shankar Cheng, Gary C. Soni, Bharat K. Chang, S. C. TI Validation and verification of Courant number insensitive CE/SE method for transient viscous flow simulations SO MATHEMATICS AND COMPUTERS IN SIMULATION LA English DT Article DE CE/SE; CFD; unsteady flows ID SPACE-TIME CONSERVATION; SOLUTION ELEMENT METHOD; EULER EQUATIONS; HIGH-RESOLUTION; NAVIER-STOKES; SCHEMES; LAWS AB In this paper, we report an extension of the space-time conservation element-solution element (CE/SE) framework-based viscous flow solver. With the accuracy of solution obtained through the use of a CE/SE-based solver closely related to the CFL number disparity across the mesh, a new formulation to make the solution insensitive to CFL number disparity is herein presented. The capability of the developed solver is then validated through simulation of 2D problems such as driven cavity, external flow over a flat plate, laminar flow over a square cylinder, etc. Investigations are also conducted to verify the sensitivity of results to grid spacing and mesh structure. (C) 2008 IMACS. Published by Elsevier B.V. All rights reserved. C1 [Venkatachari, Balaji Shankar; Cheng, Gary C.; Soni, Bharat K.] Univ Alabama Birmingham, Dept Mech Engn, Birmingham, AL 35294 USA. [Chang, S. C.] NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Venkatachari, BS (reprint author), Univ Alabama Birmingham, Dept Mech Engn, Birmingham, AL 35294 USA. EM balaji@uab.edu; gcheng@uab.edu; bsoni@uab.edu; sin-chung.chang@gre.nasa.gov NR 29 TC 7 Z9 7 U1 1 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-4754 EI 1872-7166 J9 MATH COMPUT SIMULAT JI Math. Comput. Simul. PD SEP PY 2008 VL 78 IS 5-6 BP 653 EP 670 DI 10.1016/j.matcom.2008.04.007 PG 18 WC Computer Science, Interdisciplinary Applications; Computer Science, Software Engineering; Mathematics, Applied SC Computer Science; Mathematics GA 334AQ UT WOS:000258195100008 ER PT J AU Phillips, JA Almeida, EAC Hill, EL Aguirre, JI Rivera, MF Nachbandi, I Wronski, TJ van der Meulen, MCH Globus, RK AF Phillips, Jonathan A. Almeida, Eduardo A. C. Hill, Esther L. Aguirre, J. Ignacio Rivera, Mercedes F. Nachbandi, Inaam Wronski, Thomas J. van der Meulen, Marjolein C. H. Globus, Ruth K. TI Role for beta 1 integrins in cortical osteocytes during acute musculoskeletal disuse SO MATRIX BIOLOGY LA English DT Article DE Bone; Integrin; Osteoblast; Biomechanics; Microcomputed tomography; Mechanotransduction ID OSTEOBLAST DIFFERENTIATION; BONE-FORMATION; EXTRACELLULAR-MATRIX; INTEGRIN EXPRESSION; TRANSGENIC MICE; MECHANOTRANSDUCTION; APOPTOSIS; CELLS; BETA(1)-INTEGRIN; GLUCOCORTICOIDS AB The mammalian skeleton adjusts bone structure and strength in response to changes in mechanical loading, however the molecular and cellular mechanisms governing this process in vivo are unknown. Terminally differentiated osteoblasts, the osteocytes, are presumptive mechanosensory cells for bone, and cell culture studies demonstrate that beta 1 integrins participate in mechanical signaling. To determine the role of beta 1 integrins in osteoblasts in vivo, we used the Cre-lox system to delete beta 1 integrin from cells committed to the osteoblast lineage. Wide pCol2.3 Cre-mediated recombination was widespread in bones from Col alpha I (I)-Cre(+)/beta I(fl/fl) conditional knockout mice (cKO), beta 1 integrin protein was depleted from cortical osteocytes, but not from cancellous osteocytes or cells lining bone surfaces in adults. Bones from cKO mice that were normally loaded were similar in structure to WT littermates. However. hindlimb unloading of adult cKO mice for one week intended to cause bone loss (disuse osteopenia), resulted in unexpected, rapid changes in the geometry of cortical bone; hindlimb unloading increased the cross-sectional area, marrow area, and moments of inertia in cKO, but not WT mice. Furthermore, these hindlimb unloading-induced geometric changes in cortical bone of cKO mice resulted in increased whole bone bending stiffness and strength of the femur. Together, these results confirmed the concept that osteocytes are mechanosensory cells and showed beta 1 integrins in cortical osteocytes limited changes in cortical geometry in response to disuse, thus providing the first in vivo evidence that beta 1 integrins on osteocytes mediate specific aspects of mechanotransduction. Published by Elsevier B.V. C1 [Phillips, Jonathan A.; Almeida, Eduardo A. C.; Globus, Ruth K.] NASA, Ames Res Ctr, Bone & Signaling Lab, Space Biosci Div, Moffett Field, CA 94035 USA. [Hill, Esther L.] Lockhead Martin Space Operat, Moffett Field, CA 94035 USA. [Aguirre, J. Ignacio; Rivera, Mercedes F.; Wronski, Thomas J.] Univ Florida, Dept Physiol Sci, Gainesville, FL 32610 USA. [Nachbandi, Inaam] Univ Heidelberg, Inst Immunol, D-69120 Heidelberg, Germany. [Nachbandi, Inaam] Max Planck Inst Biochem, Dept Mol Med, D-82152 Martinsried, Germany. [van der Meulen, Marjolein C. H.] Cornell Univ, Sibley Sch Mech & Aerosp Engn, Ithaca, NY 14853 USA. RP Globus, RK (reprint author), NASA, Ames Res Ctr, Bone & Signaling Lab, Space Biosci Div, Mail Stop 236-7, Moffett Field, CA 94035 USA. EM Ruth.K.Globus@nasa.gov RI van der Meulen, Marjolein/D-1549-2010 OI van der Meulen, Marjolein/0000-0001-6637-9808 FU USRA Bioastronautics; FSB Postdoctoral Fellowship; NASA-ARC; NIH-funded Musculoskeletal Repair and Regeneration Core Center [P30AR046121]; NY Space Grant FX This work was funded in part by USRA Bioastronautics and FSB Postdoctoral Fellowship to J.A.P. and NASA-ARC Directors Discretionary Fund grant to RX.G. Funding for mechanical testing was provided by the NIH-funded Musculoskeletal Repair and Regeneration Core Center (P30AR046121) and the NY Space Grant.; We thank Dr. Caroline Damsky for helpful discussions, Drs. Gerard Karsenty and Reinhard Fissler for transgenic mice, Dr. Stephen Doty for expert technical assistance with immunohistochemistry, Dr. Christopher Jacobs for use of microCT, John Lombardo and Jennifer Sasaki for animal husbandry, Simranjit Singh for his contributions to the mechanical testing, and Drs. Florent Elefteriou, NR 43 TC 24 Z9 26 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0945-053X J9 MATRIX BIOL JI Matrix Biol. PD SEP PY 2008 VL 27 IS 7 BP 609 EP 618 DI 10.1016/j.matbio.2008.05.003 PG 10 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA 378BI UT WOS:000261295700003 PM 18619537 ER PT J AU Botta, O Martins, Z Emmenegger, C Dworkin, JP Glavin, DP Harvey, RP Zenobi, R Bada, JL Ehrenfreund, P AF Botta, Oliver Martins, Zita Emmenegger, Christian Dworkin, Jason P. Glavin, Daniel P. Harvey, Ralph P. Zenobi, Renato Bada, Jeffrey L. Ehrenfreund, Pascale TI Polycyclic aromatic hydrocarbons and amino acids in meteorites and ice samples from LaPaz Icefield, Antarctica SO METEORITICS & PLANETARY SCIENCE LA English DT Article ID LASER MASS-SPECTROMETRY; YAMATO-791198 CARBONACEOUS CHONDRITES; MARTIAN METEORITE; ORGANIC-COMPOUNDS; ISOTOPIC EVIDENCE; POLAR ICE; LIQUID-CHROMATOGRAPHY; CARBOXYLIC-ACIDS; SEARCH; ALH84001 AB We have analyzed ice samples and meteorites from the LaPaz region of Antarctica to investigate the composition of polycyclic aromatic hydrocarbons (PAHs) and amino acids with the goal to understand whether or not there is a compositional relationship between the two reservoirs. Four LL5 ordinary chondrites (OCs) and one CK carbonaceous chondrite were collected as part of the 2003/2004 ANSMET season. Ice samples collected from directly underneath the meteorites were extracted. In addition, exhaust particles from the snowmobiles used during the expedition were collected to investigate possible contributions from this source. The meteorite samples, the particulate matter and solid-state extracts of the ice samples and the exhaust filters were subjected to two-step laser mass spectrometry (L2MS) to investigate the PAH composition. For amino acids analysis, the meteorites were extracted with water and acid hydrolyzed, and the extracts were analyzed with offline OPA/NAC derivatization combined with liquid chromatography with UV fluorescence detection and time of flight mass spectrometry (LC-FC/ToF-MS). PAHs in the particulate matter of the ice were found to be qualitatively similar to the meteorite samples, indicating that micron-sized grains of the meteorite may be embedded in the ice samples. The concentration levels of dissolved PAHs in all the ice samples were found to be below the detection limit of the L2MS. The PAH composition of the snowmobile exhaust is significantly different to the one in particulate matter, making it an unlikely Source of contamination for Antarctic meteorites. The amino acids glycine, beta-alanine and gamma-amino-n-butyric acid that were detected at concentrations of 3 to 19 parts per billion (ppb) are probably indigenous to the Antarctic meteorites. Some of the LaPaz ice samples were also found to contain amino acids at concentration levels of 1 to 33 parts per trillion (ppt), in particular alpha-aminoisobutyric acid (AIB), an abundant non-protein amino acid of extraterrestrial Origin found in some carbonaceous chondrites. We hypothesize that this amino acid could have been extracted from Antarctic micrometeorites and the particulate matter of the meteorites during the concentration procedure of the ice samples. C1 [Botta, Oliver; Dworkin, Jason P.; Glavin, Daniel P.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Botta, Oliver] Univ Maryland, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21228 USA. [Botta, Oliver] Int Space Sci Inst, CH-3012 Bern, Switzerland. [Martins, Zita; Ehrenfreund, Pascale] Leiden Univ, Leiden Inst Chem, Astrobiol Lab, NL-2300 RA Leiden, Netherlands. [Emmenegger, Christian; Zenobi, Renato] Eidgenoss Tech Hsch Zurich Honggerberg, Dept Chem & Appl Biosci, CH-8093 Zurich, Switzerland. [Harvey, Ralph P.] Case Western Reserve Univ, Dept Geol, Cleveland, OH 44106 USA. [Bada, Jeffrey L.] Univ Calif San Diego, Scripps Inst Oceanog, La Jolla, CA 92093 USA. RP Botta, O (reprint author), State Secretariat Educ & Res, Swiss Space Off, Hallwylstr 4, CH-3003 Bern, Switzerland. EM botta@issibern.ch RI Zenobi, Renato/F-1113-2010; Glavin, Daniel/D-6194-2012; Martins, Zita/H-4860-2015; Dworkin, Jason/C-9417-2012 OI Glavin, Daniel/0000-0001-7779-7765; Martins, Zita/0000-0002-5420-1081; Dworkin, Jason/0000-0002-3961-8997 FU Fundacao para a Ciencia e a Tecnologia [SFRH/BD/10518/2002]; European Space Agency and Verniewingsinipuls [NWO-V1 016023003] FX We would like to thank the two reviewers lain Gilmour and George Cody as well as the associate editor Kevin Righter for the very valuable comments that significantly improved the quality of the manuscript. We also like to thank the ANSMET 2003/04 field team for support in the collection and transportation of the ice samples. The NASA Astrobiology Institute and the Goddard Center for Astrobiology and the NASA Specialized Center for Research and Training in Exobiology are acknowledged for grant Support. This research was also supported by Fundacao para a Ciencia e a Tecnologia (scholarship SFRH/BD/10518/2002), the European Space Agency and Verniewingsinipuls (NWO-V1 016023003). NR 49 TC 16 Z9 18 U1 3 U2 19 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 1086-9379 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD SEP PY 2008 VL 43 IS 9 BP 1465 EP 1480 PG 16 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 385EX UT WOS:000261797500003 ER PT J AU Petro, NE Pieters, CM AF Petro, Noah E. Pieters, Carle M. TI The lunar-wide effects of basin ejecta distribution on the early megaregolith SO METEORITICS & PLANETARY SCIENCE LA English DT Article ID POLE-AITKEN BASIN; MULTIRING BASINS; CRATER EJECTA; MOON; SURFACE; CRUST; REGOLITH; METEORITES; ORIGIN; THICKNESS AB The lunar Surface is marked by at least 43 large and ancient impact basins, each of which ejected a large amount of material that modified the areas Surrounding each basin. We present an analysis of the effects of basin formation on the entire lunar surface using a previously defined basin ejecta model. Our modeling includes several simplifying assumptions in order to quantify two aspects of basin formation across the entire lunar Surface: 1) the Cumulative amount of material distributed across the surface, and 2) the depth to which that basin material created a well-mixed megaregolith. We find that the asymmetric distribution of large basins across the Moon creates a considerable nearside-farside dichotomy in both the Cumulative amount of basin ejecta and the depth of the megaregolith. Basins significantly modified a large portion of the nearside while the farside experienced relatively small degrees of basin modification following the formation of the large South Pole-Aitken basin. The regions of the Moon with differing degrees of modification by basins correspond to regions thought to contain geochemical signatures remnant of early lunar crustal processes, indicating that the degree of basin modification of the surface directly influenced the distribution of the geochemical terranes observed today. Additionally, the modification of the lunar Surface by basins suggests that the provenance Of lunar highland samples Currently in research collections is not representative of the entire lunar crust. Identifying locations oil the lunar Surface with unique modification histories will aid in selecting locations for future sample collection. C1 [Petro, Noah E.; Pieters, Carle M.] Brown Univ, Dept Geol Sci, Providence, RI 02912 USA. RP Petro, NE (reprint author), NASA, Goddard Space Flight Ctr, Planetary Geodynam Lab, Code 698, Greenbelt, MD 20771 USA. EM noah.e.petro@nasa.gov RI Petro, Noah/F-5340-2013 FU NASA [NNG-05G100G] FX The authors would like to acknowledge the excellent and through reviews by Brad Jolliff and Boris Ivanov as well as the funding support NASA grant NNG-05G100G. NR 58 TC 22 Z9 23 U1 1 U2 9 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 1086-9379 EI 1945-5100 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD SEP PY 2008 VL 43 IS 9 BP 1517 EP 1529 PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 385EX UT WOS:000261797500007 ER PT J AU Mackenzie, AI Baginski, ME Rao, SM AF Mackenzie, Anne I. Baginski, Michael E. Rao, Sadasiva M. TI An alternate set of basis functions for the electromagnetic solution of arbitrarily shaped, three-dimensional, closed, conducting bodies using method of moments SO MICROWAVE AND OPTICAL TECHNOLOGY LETTERS LA English DT Article DE method of moments; integral equations; electromagnetic scattering; numerical methods AB In this work, we present an alternate set of basis functions, each defined over a pair of planar triangular patches, for the method of moments solution of electromagnetic scattering and radiation problems associated with arbitrarily shaped, closed, conducting surfaces. The present basis functions are point-wise orthogonal to the pulse basis functions previously defined. The prime motivation to develop the present set of basis functions is to utilize them for the electromagnetic solution of dielectric bodies using a surface integral equation formulation which involves both electric and magnetic currents. However, in the present work, only the conducting body solution is presented and compared with other data. (C) 2008 Wiley Periodicals, Inc. C1 [Baginski, Michael E.; Rao, Sadasiva M.] Auburn Univ, Dept E & CE, Auburn, AL 36849 USA. [Mackenzie, Anne I.] NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Rao, SM (reprint author), Auburn Univ, Dept E & CE, Auburn, AL 36849 USA. EM rao@eng.auburn.edu NR 5 TC 0 Z9 0 U1 0 U2 0 PU JOHN WILEY & SONS INC PI HOBOKEN PA 111 RIVER ST, HOBOKEN, NJ 07030 USA SN 0895-2477 J9 MICROW OPT TECHN LET JI Microw. Opt. Technol. Lett. PD SEP PY 2008 VL 50 IS 9 BP 2354 EP 2357 DI 10.1002/mop.23681 PG 4 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA 327KJ UT WOS:000257727700037 ER PT J AU Lin, II Wu, CC Pun, IF Ko, DS AF Lin, I. -I. Wu, Chun-Chieh Pun, Iam-Fei Ko, Dong-Shan TI Upper-ocean thermal structure and the western North Pacific category 5 typhoons. Part I: Ocean features and the category 5 typhoons' intensification SO MONTHLY WEATHER REVIEW LA English DT Article ID TROPICAL CYCLONE INTENSITY; SEA-SURFACE TEMPERATURE; MIXED-LAYER RESPONSE; HURRICANE INTENSITY; VARIABILITY; EDDY; TRANSPORT; ALTIMETRY; CLIMATE; MODEL AB Category 5 cyclones are the most intense and devastating cyclones on earth. With increasing observations of category 5 cyclones, such as Hurricane Katrina (2005), Rita (2005), Mitch (1998), and Supertyphoon Maemi (2003) found to intensify on warm ocean features (i. e., regions of positive sea surface height anomalies detected by satellite altimeters), there is great interest in investigating the role ocean features play in the intensification of category 5 cyclones. Based on 13 yr of satellite altimetry data, in situ and climatological upper-ocean thermal structure data, best-track typhoon data of the U. S. Joint Typhoon Warning Center, together with an ocean mixed layer model, 30 western North Pacific category 5 typhoons that occurred during the typhoon season from 1993 to 2005 are systematically examined in this study. Two different types of situations are found. The first type is the situation found in the western North Pacific south eddy zone (SEZ; 21-26 N, 127-170 E) and the Kuroshio (21-30 N, 127-170 E) region. In these regions, the background climatological warm layer is relatively shallow (typically the depth of the 26 C isotherm is around 60 m and the upper-ocean heat content is similar to 50 kJ cm(-2)). Therefore passing over positive features is critical to meet the ocean's part of necessary conditions in intensification because the features can effectively deepen the warm layer (depth of the 26 C isotherm reaching 100 m and upper-ocean heat content is similar to 110 kJ cm(-2)) to restrain the typhoon's self-induced ocean cooling. In the past 13 yr, 8 out of the 30 category 5 typhoons (i. e., 27%) belong to this situation. The second type is the situation found in the gyre central region (10 degrees-21 degrees N, 121 degrees-170 degrees E) where the background climatological warm layer is deep (typically the depth of the 26 C isotherm is similar to 105-120 m and the upper-ocean heat content is similar to 80-120 kJ cm(-2)). In this deep, warm background, passing over positive features is not critical since the background itself is already sufficient to restrain the self-induced cooling negative feedback during intensification. C1 [Lin, I. -I.; Wu, Chun-Chieh; Pun, Iam-Fei] Natl Taiwan Univ, Dept Atmospher Sci, Taipei 106, Taiwan. [Ko, Dong-Shan] USN, Res Lab, Stennis Space Ctr, Washington, DC 20375 USA. RP Lin, II (reprint author), Natl Taiwan Univ, Dept Atmospher Sci, 1 Sec 4,Roosevelt Rd, Taipei 106, Taiwan. EM iilin@as.ntu.edu.tw RI Lin, I-I/J-4695-2013; OI Lin, I-I/0000-0002-8364-8106; Wu, Chun-Chieh/0000-0002-3612-4537 FU National Science Council, Taiwan [NSC95-2611-M-002-024-MY3, NSC97-2111-M-002-014-MY3, NTU-97R0302]; Taiwan National Science Council's Integrated Typhoon-Ocean Program (ITOP); US Office of Naval Research's Typhoon DRI FX The authors thank Dr. Colin Stark for his helpful comments and Prof. Dong-Ping Wang for providing the mixed layer model and helpful discussions. Thanks also to NASA, Remote Sensing Systems, Argo in situ ocean float team, and the Joint Typhoon Warning Center for data provision. This work is supported by the National Science Council, Taiwan through Grants NSC95-2611-M-002-024-MY3, NSC97-2111-M-002-014-MY3, and NTU-97R0302. This work is also a collaborative effort between Taiwan National Science Council's Integrated Typhoon-Ocean Program (ITOP) and the US Office of Naval Research's Typhoon DRI program. NR 51 TC 106 Z9 110 U1 2 U2 14 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 SEP PY 2008 VL 136 IS 9 BP 3288 EP 3306 DI 10.1175/2008MWR2277.1 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 349QF UT WOS:000259295200005 ER PT J AU Carlson, AE Legrande, AN Oppo, DW Came, RE Schmidt, GA Anslow, FS Licciardi, JM Obbink, EA AF Carlson, Anders E. Legrande, Allegra N. Oppo, Delia W. Came, Rosemarie E. Schmidt, Gavin A. Anslow, Faron S. Licciardi, Joseph M. Obbink, Elizabeth A. TI Rapid early Holocene deglaciation of the Laurentide ice sheet SO NATURE GEOSCIENCE LA English DT Article ID SEA-LEVEL RECORD; NORTH-ATLANTIC; LABRADOR SEA; CLIMATE; EVENT; TEMPERATURE; VARIABILITY; SIMULATIONS AB The demise of the Laurentide ice sheet during the early Holocene epoch is the most recent and best constrained disappearance of a large ice sheet in the Northern Hemisphere, and thus allows an assessment of rates of ice-sheet decay as well as attendant contributions to sea level rise. Here, we use terrestrial and marine records of the deglaciation to identify two periods of rapid melting during the final demise of the Laurentide ice sheet, when melting ice contributed about 1.3 and 0.7 cm of sea level rise per year, respectively. Our simulations with a fully coupled ocean-atmosphere model suggest that increased ablation due to enhanced early Holocene boreal summer insolation was the predominant cause of Laurentide ice-sheet retreat. Although the surface radiative forcing in boreal summer during the early Holocene is twice as large as the greenhouse-gas forcing expected by the year 2100, the associated increase in summer surface air temperatures is very similar. We conclude that our geologic evidence for a rapid retreat of the Laurentide ice sheet may therefore describe a prehistoric precedent for mass balance changes of the Greenland ice sheet over the coming century. C1 [Carlson, Anders E.; Obbink, Elizabeth A.] Univ Wisconsin, Dept Geol & Geophys, Madison, WI 53706 USA. [Legrande, Allegra N.; Schmidt, Gavin A.] Columbia Univ, NASA, Goddard Inst Space Studies, New York, NY 10025 USA. [Legrande, Allegra N.; Schmidt, Gavin A.] Columbia Univ, Ctr Climate Syst Res, New York, NY 10025 USA. [Oppo, Delia W.] Woods Hole Oceanog Inst, Dept Geol & Geophys, Woods Hole, MA 02543 USA. [Came, Rosemarie E.] CALTECH, Pasadena, CA 91125 USA. [Anslow, Faron S.] Univ British Columbia, Vancouver, BC V6T 1Z4, Canada. [Licciardi, Joseph M.] Univ New Hampshire, Dept Earth Sci, Durham, NH 03824 USA. RP Carlson, AE (reprint author), Univ Wisconsin, Dept Geol & Geophys, Madison, WI 53706 USA. EM acarlson@geology.wisc.edu RI Schmidt, Gavin/D-4427-2012; LeGrande, Allegra/D-8920-2012 OI Schmidt, Gavin/0000-0002-2258-0486; LeGrande, Allegra/0000-0002-5295-0062 FU National Science Foundation [ATM-05-01351, ATM-05-01241]; University of Wisconsin-Madison; Woods Hole Oceanographic Institution Postdoctoral Scholarship; Woods Hole Oceanographic Institution's Ocean and Climate Change Institute FX We would like to thank J. Stoner for discussion of Orphan Knoll cores, and L. Keigwin and L. Skinner for sharing data. This research was financially supported by National Science Foundation grants ATM-05-01351 & ATM-05-01241 to D. W. O. and G. A. S., start-up funds from the University of Wisconsin-Madison and a Woods Hole Oceanographic Institution Postdoctoral Scholarship to A. E. C., and the Woods Hole Oceanographic Institution's Ocean and Climate Change Institute (D. W. O. and R. E. C.). NR 30 TC 109 Z9 114 U1 0 U2 33 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 SEP PY 2008 VL 1 IS 9 BP 620 EP 624 DI 10.1038/ngeo285 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 343ZJ UT WOS:000258894700019 ER PT J AU Gebre, T Batra, AK Bhat, K Aggarwal, MD Penn, BG Edwards, ME AF Gebre, T. Batra, A. K. Bhat, K. Aggarwal, M. D. Penn, B. G. Edwards, M. E. TI Growth and characteristics of Schiff base organic nonlinear optical crystals SO OPTOELECTRONICS AND ADVANCED MATERIALS-RAPID COMMUNICATIONS LA English DT Article DE NLO crystals; Schiff base compound; crystal growth; Bridgman technique AB The synthesis and crystal growth of a new organic nonlinear optical material, a Schiff base compound, 4-nitrobenzylidene-4-chloroaniline is reported. Good-quality crystals have been successfully grown using Bridgman-Stockbarger technique. The synthesized material has been characterized via Fourier transform infrared (FTIR) spectroscopy and DSC studies. Nonlinear optical activity of the organic crystal, 4-nitrobenzylidene-4-chloroaniline, shows good second harmonic generation of 1.064 micron wavelength. C1 [Batra, A. K.; Aggarwal, M. D.; Edwards, M. E.] Alabama A&M Univ, Dept Phys, Normal, AL 35762 USA. [Gebre, T.] Natl High Magnet Field Lab, Tallahassee, FL 32310 USA. [Bhat, K.] Alabama A&M Univ, Dept Chem, Normal, AL 35762 USA. [Penn, B. G.] NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Batra, AK (reprint author), Alabama A&M Univ, Dept Phys, POB 1268, Normal, AL 35762 USA. EM ashok.batra@aamu.edu FU NSF Capacity Building [0236425]; NASA Alliance for nonlinear optics [NAG81623, NAGS-1708]; NASA Administrator's Fellowship Program (NAFP) [NNG066C58A] FX Thanks are due to present and past graduate students for their assistance in the design of crystal growth apparatus and technical assistance. The partial supports of this work through the NSF Capacity Building grant no. 0236425, NASA Alliance for nonlinear optics, NAG81623 and NAGS-1708 are gratefully acknowledged. One of the authors (MDA) would like to acknowledge support from NASA Administrator's Fellowship Program (NAFP) through United Negro College Fund Special Programs (UNCFSP) Corporation under the contract # NNG066C58A. NR 9 TC 1 Z9 1 U1 0 U2 1 PU NATL INST OPTOELECTRONICS PI BUCHAREST-MAGURELE PA 1 ATOMISTILOR ST, PO BOX MG-5, BUCHAREST-MAGURELE 76900, ROMANIA SN 1842-6573 J9 OPTOELECTRON ADV MAT JI Optoelectron. Adv. Mater.-Rapid Commun. PD SEP PY 2008 VL 2 IS 9 BP 578 EP 581 PG 4 WC Materials Science, Multidisciplinary; Optics SC Materials Science; Optics GA 354MC UT WOS:000259642700012 ER PT J AU Stoker, J Harding, D Parrish, J AF Stoker, Jason Harding, David Parrish, Jay TI The need for a National Lidar Dataset SO PHOTOGRAMMETRIC ENGINEERING AND REMOTE SENSING LA English DT Article C1 [Harding, David] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. EM jstoker@usgs.gov; david.j.harding@nasa.gov; jayparrish@state.pa.us RI Harding, David/F-5913-2012; OI Stoker, Jason/0000-0003-2455-0931 NR 0 TC 20 Z9 20 U1 0 U2 3 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 SEP PY 2008 VL 74 IS 9 BP 1066 EP 1068 PG 3 WC Geography, Physical; Geosciences, Multidisciplinary; Remote Sensing; Imaging Science & Photographic Technology SC Physical Geography; Geology; Remote Sensing; Imaging Science & Photographic Technology GA 344FP UT WOS:000258912600001 ER PT J AU Alim, MA Bissell, SR Mobasher, AA AF Alim, Mohammad A. Bissell, Stephen R. Mobasher, Amir A. TI Analysis of the AC electrical data in the Davidson-Cole dielectric representation SO PHYSICA B-CONDENSED MATTER LA English DT Article DE complex planes; relaxation time; equivalent circuit; Debye and non-Debye relaxations; electrochemical impedance spectroscopy ID STATE AB The representation of the AC electrical data in the complex plane reveal two major classifications of the relaxation processes known as ideal (Debye) and non-ideal (non-Debye) types. The non-Debye relaxation has been empirically observed via Cole-Cole (C-C), Davidson-Cole (D-C), and Havriliak-Negami (H-N) responses. Each of these non-Debye relaxations is visualized with an equivalent circuit similar to the ideal relaxation. Both ideal and C-C relaxations reveal semicircular behavior in the complex plane while D-C and H-N relaxations deviate from the usual semicircular loci known as skewed behavior. The extracted equivalent circuit elements are essentially non-Debye for both D-C and H-N relaxations possessing complexity in the relaxation time. The analytical method of extracting these elements in conjunction with the empirical parameters of the D-C relaxation is described using conventional (real) domain and complex domain. The curve fitting procedure provided extremely small error for the complex domain analysis. The behavior of the D-C relaxation function and the depression parameter beta are also discussed using omega(tau) = 1 and omega(tau)not equal 1 corresponding to the maximum of the imaginary part of the impedance (Z*) or permittivity (epsilon*). (C) 2008 Elsevier B.V. All rights reserved. C1 [Alim, Mohammad A.] Alabama A&M Univ, Dept Elect Engn, Normal, AL 35762 USA. [Bissell, Stephen R.] Venable Ind, Austin, TX 78745 USA. [Mobasher, Amir A.] Alabama A&M Univ, Dept Mech Engn, Normal, AL 35762 USA. [Alim, Mohammad A.] NASA, George C Marshall Space Flight Ctr, Integrated Syst Hlth Management & Sensors Branch, Huntsville, AL 35812 USA. RP Alim, MA (reprint author), Alabama A&M Univ, Dept Elect Engn, POB 297, Normal, AL 35762 USA. EM mohammad.alim@aamu.edu NR 22 TC 6 Z9 6 U1 1 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD SEP 1 PY 2008 VL 403 IS 18 BP 3040 EP 3053 DI 10.1016/j.physb.2008.03.016 PG 14 WC Physics, Condensed Matter SC Physics GA 354GI UT WOS:000259626500016 ER PT J AU Young, JA Surko, CM AF Young, J. A. Surko, C. M. TI Feshbach-resonance-mediated positron annihilation in small molecules SO PHYSICAL REVIEW A LA English DT Article ID BOUND-STATES; CONFIGURATION-INTERACTION; BINDING; ATOMS; SPECTRA; MODEL; EXCITATION; SCATTERING; GASES; RATES AB Large positron annihilation cross sections have been observed for a variety of molecules at various energies below the threshold for positronium formation. These large values are due to vibrational Feshbach resonances (VFRs), in which the positron attaches to the molecule while exciting a vibration. This leads to rates of annihilation far greater than those expected for a simple collision. The dependence of the annihilation rate on incident positron energy can be used to deduce positron-molecule binding energies. Presented here is a comprehensive study of resonant annihilation in small molecules (e.g., hydrocarbons with one or two carbon atoms). In some cases, only fundamental vibrations are important, and theory correctly predicts the annihilation rates as a function of incident positron energy. In other cases, combination and overtone vibrations are shown to support Feshbach resonances. In the subset of these cases where the positron-molecule coupling strengths can be determined for these combination modes, theoretical predictions are in agreement with the measurements. Finally, there are species that do not exhibit VFRs, such as carbon dioxide. This is interpreted as evidence that positrons bind very weakly or not at all to these targets. Several of these molecules exhibit a variety of behaviors that are presently unexplained. The implications of the results presented here for more comprehensive theories of positron annihilation on molecules are discussed. C1 [Young, J. A.; Surko, C. M.] Univ Calif San Diego, Dept Phys, La Jolla, CA 92093 USA. RP Young, JA (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. FU National Science Foundation [02-44653] FX We wish to acknowledge extensive discussions with G. F. Gribakin on many aspects of this work, helpful conversations with C. M. R. Lee, J. P. Marler, and J. R. Danielson, and the expert assistance of E. A. Jerzewski. This work is supported by the National Science Foundation Grant No. 02-44653. NR 51 TC 28 Z9 28 U1 0 U2 4 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 SEP PY 2008 VL 78 IS 3 AR 032702 DI 10.1103/PhysRevA.78.032702 PG 14 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 355DO UT WOS:000259689400093 ER PT J AU May, AF Fleurial, JP Snyder, GJ AF May, Andrew F. Fleurial, Jean-Pierre Snyder, G. Jeffrey TI Thermoelectric performance of lanthanum telluride produced via mechanical alloying SO PHYSICAL REVIEW B LA English DT Article ID CERIUM SULFIDE; ELECTRONIC TRANSPORT; CHALCOGENIDES; BAND AB Lanthanum telluride (La(3-x)Te(4)) has been synthesized via mechanical alloying and characterized for thermoelectric performance. This work confirms prior reports of lanthanum telluride as a good high-temperature thermoelectric material, with zT similar to 1.1 obtained at 1275 K. The thermoelectric performance is found to be better than that of SiGe, the current state-of-the-art high-temperature n-type thermoelectric material. Inherent self-doping of the system allows control over carrier concentration via sample stoichiometry. Prior high-temperature syntheses were prone to solute rejection in liquid and vapor phases, which resulted in inhomogeneous chemical composition and carrier concentration. The low-temperature synthesis provides homogeneous samples with acceptable control of the stoichiometry, and thus allows a thorough examination of the transition from a heavily doped degenerate semiconductor to a nondegenerate semiconductor. The effect of carrier concentration on the Hall mobility, Seebeck coefficient, thermal and electrical conductivity, lattice thermal conductivity, and thermoelectric compatibility are examined for 0.03 <= x <= 0.33. C1 [May, Andrew F.] CALTECH, Dept Chem Engn, Pasadena, CA 91125 USA. [Fleurial, Jean-Pierre] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Snyder, G. Jeffrey] CALTECH, Dept Mat Sci, Pasadena, CA 91125 USA. RP May, AF (reprint author), CALTECH, Dept Chem Engn, 1200 E Calif Blvd, Pasadena, CA 91125 USA. RI May, Andrew/E-5897-2011; Snyder, G. Jeffrey/E-4453-2011; Snyder, G/I-2263-2015 OI May, Andrew/0000-0003-0777-8539; Snyder, G. Jeffrey/0000-0003-1414-8682; FU Jet Propulsion Laboratory; California Institute of Technology; National Aeronautics and Space Administration FX The authors thank the JPL Thermoelectrics Group for help various measurements and Sossina Haile for useful discussions regarding material processing. They thank Teruyuki Ikeda for performing the electron microprobe measurements and Chi Ma of the Caltech GPS Analytical Facility for discussions regarding the ZAF correction employed. Richard Blair is acknowledged for useful discussions regarding mechanical alloying and crystallite size determination, as are J. Aldrich and Y. Bar-Cohen for providing equipment and assistance with the ultrasonic measurements. 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. NR 40 TC 85 Z9 85 U1 7 U2 63 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD SEP PY 2008 VL 78 IS 12 AR 125205 DI 10.1103/PhysRevB.78.125205 PG 12 WC Physics, Condensed Matter SC Physics GA 355EH UT WOS:000259691500038 ER PT J AU Sperhake, U Berti, E Cardoso, V Gonzalez, JA Brugmann, B Ansorg, M AF Sperhake, Ulrich Berti, Emanuele Cardoso, Vitor Gonzalez, Jose A. Bruegmann, Bernd Ansorg, Marcus TI Eccentric binary black-hole mergers: The transition from inspiral to plunge in general relativity SO PHYSICAL REVIEW D LA English DT Article ID POST-NEWTONIAN MOTION; LASER-INTERFEROMETER; NUMERICAL RELATIVITY; GRAVITATIONAL-RADIATION; COMPACT BINARIES; INITIAL DATA; WAVE-FORMS; EVOLUTION; DYNAMICS; GAS AB We study the transition from inspiral to plunge in general relativity by computing gravitational waveforms of nonspinning, equal- mass black- hole binaries. We consider three sequences of simulations, starting with a quasicircular inspiral completing 1.5, 2.3 and 9.6 orbits, respectively, prior to coalescence of the holes. For each sequence, the binding energy of the system is kept constant and the orbital angular momentum is progressively reduced, producing orbits of increasing eccentricity and eventually a head- on collision. We analyze in detail the radiation of energy and angular momentum in gravitational waves, the contribution of different multipolar components and the final spin of the remnant, comparing numerical predictions with the post- Newtonian approximation and with extrapolations of point- particle results. We find that the motion transitions from inspiral to plunge when the orbital angular momentum L = L-crit similar or equal to 0: 8M(2). For L< L-crit the radiated energy drops very rapidly. Orbits with L similar or equal to L-crit produce our largest dimensionless Kerr parameter for the remnant, j = J/M-2 similar or equal to 0.724 +/- 0.13 (to be compared with the Kerr parameter j similar or equal to 0.69 resulting from quasicircular inspirals). This value is in good agreement with the value of 0.72 reported in [I. Hinder, B. Vaishnav, F. Herrmann, D. Shoemaker, and P. Laguna, Phys. Rev. D 77, 081502 (2008).]. These conclusions are quite insensitive to the initial separation of the holes, and they can be understood by extrapolating point- particle results. Generalizing a model recently proposed by Buonanno, Kidder and Lehner [A. Buonanno, L. E. Kidder, and L. Lehner, Phys. Rev. D 77, 026004 (2008).] to eccentric binaries, we conjecture that (1) j similar or equal to 0.724 is close to the maximal Kerr parameter that can be obtained by any merger of nonspinning holes, and (2) no binary merger (even if the binary members are extremal Kerr black holes with spins aligned to the orbital angular momentum, and the inspiral is highly eccentric) can violate the cosmic censorship conjecture. C1 [Sperhake, Ulrich; Gonzalez, Jose A.; Bruegmann, Bernd] Univ Jena, Inst Theoret Phys, D-07743 Jena, Germany. [Berti, Emanuele] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Berti, Emanuele] Washington Univ, Dept Phys, McDonnell Ctr Space Sci, St Louis, MO 63130 USA. [Cardoso, Vitor] Univ Mississippi, Dept Phys & Astron, University, MS 38677 USA. [Cardoso, Vitor] Inst Super Tecn, Dept Fis, Ctr Multidisciplinar Astrofis CENTRA, P-1049001 Lisbon, Portugal. [Gonzalez, Jose A.] Univ Michoacana, Inst Fis & Matemat, Morelia 58040, Michoacan, Mexico. [Ansorg, Marcus] Albert Einstein Inst, Max Planck Inst Gravitat Phys, D-14476 Golm, Germany. RP Sperhake, U (reprint author), Univ Jena, Inst Theoret Phys, D-07743 Jena, Germany. EM ulrich.sperhake@uni-jena.de 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 Jet Propulsion Laboratory,; California Institute of Technology; National Science Foundation [PHY 03- 53180]; NASA [NNG06GI60]; Fundacao para a Ciencia e Tecnologia (FCT)-Portugal [PTDC/FIS/64175/2006, POCI/ FP/81915/2007] FX We thank Clifford Will, Achamveedu Gopakumar, Christian Konigsdorffer and Gerhard Schafer for discussions about eccentricity in the PN formalism, and Luciano Rezzolla and Michele Vallisneri for comments on the manuscript. This work was supported in part by DFG Grant No. SFB/ Transregio 7 "Gravitational Wave Astronomy.'' E. B.' s research was supported by a contract with NASA to the Jet Propulsion Laboratory, California Institute of Technology; by the National Science Foundation, under Grant No. PHY 03- 53180; and by NASA, under Grant No. NNG06GI60 to Washington University. V. C.' s work was partially funded by Fundacao para a Ciencia e Tecnologia (FCT)-Portugal through Projects No. PTDC/FIS/64175/2006 and No. POCI/ FP/81915/2007. We thank the DEISA Consortium (cofunded by the EU, FP6 Project No. 508830), for support within the DEISA Extreme Computing Initiative (www. deisa. org). Computations were performed at LRZ Munich and the Doppler and Kepler clusters at the Institute of Theoretical Physics of the University of Jena. We are grateful to the Center for Computational Physics (CFC) in Coimbra for granting us access to the Milipeia cluster. NR 90 TC 54 Z9 54 U1 0 U2 4 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 SEP PY 2008 VL 78 IS 6 AR 064069 DI 10.1103/PhysRevD.78.064069 PG 22 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 355ES UT WOS:000259692800140 ER PT J AU Jiang, WY Kuang, WJ AF Jiang, Weiyuan Kuang, Weijia TI An MPI-based MoSST core dynamics model SO PHYSICS OF THE EARTH AND PLANETARY INTERIORS LA English DT Article DE Planetary dynamo; Numerical modeling; Parallel computing ID SPHERICAL-SHELLS; CONVECTION; FIELD; GENERATION; GEODYNAMO AB Distributed systems are among the main cost-effective and expandable platforms for high-end scientific computing. Therefore scalable numerical models are important for effective use of such systems. In this paper, we present an MPI-based numerical core dynamics model for simulation of geodynamo and planetary dynamos, and for simulation of core-mantle interactions. The model is developed based on MPI libraries. Two algorithms are used for node-node communication: a "master-slave" architecture and a "divide-and-conquer" architecture. The former is easy to implement but not scalable in communication. The latter is scalable in both computation and communication. The model scalability is tested on Linux PC clusters with up to 128 nodes. This model is also benchmarked with a published numerical dynamo model solution. (C) 2008 Elsevier B.V. All rights reserved. C1 [Jiang, Weiyuan] Univ Maryland Baltimore Cty, Joint Ctr Earth Syst Technol, Baltimore, MD 21228 USA. [Kuang, Weijia] NASA, Goddard Space Flight Ctr, Planetary Geodynam Lab, Greenbelt, MD 20771 USA. RP Jiang, WY (reprint author), Univ Maryland Baltimore Cty, Joint Ctr Earth Syst Technol, Baltimore, MD 21228 USA. EM jiangw@umbc.edu; Weijia.Kuang-1@nasa.gov RI Kuang, Weijia/K-5141-2012 OI Kuang, Weijia/0000-0001-7786-6425 FU NASA; GSFC; NPPCS FX This research is supported by NASA Mars Fundamental Research Program, NASA Solid Earth and Natural Hazard Program and NASA Earth Surface and Interior Program. We also thank NASA GSFC NPPCS and NASA NAS for computation support. NR 17 TC 4 Z9 4 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0031-9201 J9 PHYS EARTH PLANET IN JI Phys. Earth Planet. Inter. PD SEP PY 2008 VL 170 IS 1-2 BP 46 EP 51 DI 10.1016/j.pepi.2008.07.020 PG 6 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 373NQ UT WOS:000260979100005 ER PT J AU McConkey, JW Malone, CP Johnson, PV Winstead, C McKoy, V Kanik, I AF McConkey, J. W. Malone, C. P. Johnson, P. V. Winstead, C. McKoy, V. Kanik, I. TI Electron impact dissociation of oxygen-containing molecules - A critical review SO PHYSICS REPORTS-REVIEW SECTION OF PHYSICS LETTERS LA English DT Review DE dissociation; oxygen; electron impact; cross sections ID IONIZATION CROSS-SECTIONS; NEGATIVE-ION FORMATION; LOW-ENERGY ELECTRONS; EXTREME-ULTRAVIOLET EMISSION; CARBON-DIOXIDE CLUSTERS; RYDBERG FRAGMENT ATOMS; LARGE WATER CLUSTERS; GAS-PHASE GLYCINE; ABSOLUTE OSCILLATOR-STRENGTHS; EXCITED FESHBACH RESONANCES AB The dissociation of a wide range of oxygen-containing molecules following impact with electrons of carefully controlled energy is critically reviewed. Molecules considered range from diatomics, like O-2 and CO, to large molecules of biological and technological interest. Dissociation mechanisms are discussed and, where possible, quantitative data for the various possible processes, ionization, attachment, dissociation, excitation, emission etc., are presented. Gaps and discrepancies in our current data base are highlighted. Both graphical and tabular data are presented. (C) 2008 Elsevier B.V. All rights reserved. C1 [McConkey, J. W.] Univ Windsor, Dept Phys, Windsor, ON N9B 3P4, Canada. [McConkey, J. W.; Malone, C. P.; Johnson, P. V.; Kanik, I.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Winstead, C.; McKoy, V.] CALTECH, Arthur Amos Noyes Lab Chem Phys, Pasadena, CA 91125 USA. RP McConkey, JW (reprint author), Univ Windsor, Dept Phys, Sunset Ave, Windsor, ON N9B 3P4, Canada. EM mcconk@uwindsor.ca; isik.kanik@jpl.nasa.gov RI Johnson, Paul/D-4001-2009; Malone, Charles/A-6294-2010 OI Johnson, Paul/0000-0002-0186-8456; Malone, Charles/0000-0001-8418-1539 FU National Aeronautics and Space Administration; Planetary Atmospheres and Outer Planets Research; Natural Sciences and Engineering Research Council of Canada; U.S. Department of Energy FX This work was performed at the Jet Propulsion Laboratory (JPL), California Institute of Technology (Caltech), under a contract with the National Aeronautics and Space Administration (NASA), and at Caltech. We gratefully acknowledge financial support through NASA's Planetary Atmospheres and Outer Planets Research programs as well as from the U.S. Department of Energy, Office of Basic Energy Sciences, and from the Natural Sciences and Engineering Research Council of Canada. This research was performed while CPM and JWMcC held NASA Fellowships at JPL. Kate Mendenhall provided invaluable assistance in the preparation of tabular and graphical material. The authors thank the referee for many helpful suggestions. NR 684 TC 73 Z9 74 U1 5 U2 77 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-1573 EI 1873-6270 J9 PHYS REP JI Phys. Rep.-Rev. Sec. Phys. Lett. PD SEP PY 2008 VL 466 IS 1-3 BP 1 EP 103 DI 10.1016/j.physrep.2008.05.001 PG 103 WC Physics, Multidisciplinary SC Physics GA 354GE UT WOS:000259626100001 ER PT J AU Silk, EA Dash, PH AF Silk, E. A. Dash, P. H. TI Risk management in space systems design and technology development SO PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART G-JOURNAL OF AEROSPACE ENGINEERING LA English DT Article DE spacecraft development; technology development; risk management; risk analysis AB Over the past two decades, risk management and risk analysis have emerged throughout the business community in the USA as prominent planning and development strategies used to mitigate risk of failure and to ensure a high return on investment for business endeavours (financial and otherwise). They are generic tools that can be applied to any business regardless of the sector (i.e. government, university, and private) and have been used by the Federal Government in the form of institutional practices aimed at maximizing the probability of success in business activities. One US Federal agency that incorporates risk management and analysis techniques into business and/or engineering activities is the National Aeronautics and Space Administration. The present work is a discussion on mission, spacecraft and instrument design (as well as technology development), and the role of risk management, analysis, and mitigation as fundamental tools in the design process. C1 [Silk, E. A.] NASA, Goddard Space Flight Ctr, Thermal Engn Technol Dev Grp, Greenbelt, MD 20771 USA. [Dash, P. H.] Booz Allen & Hamilton Inc, Econ & Business Anal Grp, Los Angeles, CA USA. RP Silk, EA (reprint author), NASA, Goddard Space Flight Ctr, Thermal Engn Technol Dev Grp, Bldg 7,Room 215, Greenbelt, MD 20771 USA. EM eric.a.silk@nasa.gov FU Thermal Engineering Branch; NASA Goddard Space Flight Centre; Economic and Business Analysis group FX E. A. Silk was supported by the Thermal Engineering Branch and the Technology Transfer office at the NASA Goddard Space Flight Centre. P Dash was supported by the Economic and Business Analysis group of Booz Allen Hamilton in Los Angeles, CA, USA. Special thanks to Dan Butler of NASA Goddard Space Flight Centre's Thermal Engineering Branch for his insights. NR 7 TC 5 Z9 5 U1 0 U2 1 PU PROFESSIONAL ENGINEERING PUBLISHING LTD PI WESTMINISTER PA 1 BIRDCAGE WALK, WESTMINISTER SW1H 9JJ, ENGLAND SN 0954-4100 J9 P I MECH ENG G-J AER JI Proc. Inst. Mech. Eng. Part G-J. Aerosp. Eng. PD SEP PY 2008 VL 222 IS G6 BP 907 EP 913 DI 10.1243/09544100JAERO300 PG 7 WC Engineering, Aerospace; Engineering, Mechanical SC Engineering GA 361VI UT WOS:000260154900017 ER PT J AU Aspey, RA McDermid, IS Leblanc, T Howe, JW Walsh, TD AF Aspey, R. A. McDermid, I. S. Leblanc, T. Howe, J. W. Walsh, T. D. TI LABVIEW graphical user interface for precision multichannel alignment of Raman lidar at Jet Propulsion Laboratory, Table Mountain Facility SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID WATER-VAPOR; TEMPERATURE; STRATOSPHERE; BACKSCATTER; TROPOSPHERE; ABSORPTION AB The Jet Propulsion Laboratory operates lidar systems at Table Mountain Facility (TMF), California (34.4 degrees N, 117.7 degrees W) and Mauna Loa Observatory, Hawaii (19.5 degrees N, 155.6 degrees W) under the framework of the Network for the Detection of Atmospheric Composition Change. To complement these systems a new Raman lidar has been developed at TMF with particular attention given to optimizing water vapor profile measurements up to the tropopause and lower stratosphere. The lidar has been designed for accuracies of 5% up to 12 km in the free troposphere and a detection capability of <5 ppmv. One important feature of the lidar is a precision alignment system using range resolved data from eight Licel transient recorders, allowing fully configurable alignment via a LABVIEW/ C++ graphical user interface (GUI). This allows the lidar to be aligned on any channel while simultaneously displaying signals from other channels at configurable altitude/bin combinations. The general lidar instrumental setup and the details of the alignment control system, data acquisition, and GUI alignment software are described. Preliminary validation results using radiosonde and lidar intercomparisons are briefly presented. (C) 2008 American Institute of Physics. [DOI: 10.1063/1.2976672] C1 [Aspey, R. A.; McDermid, I. S.; Leblanc, T.; Howe, J. W.; Walsh, T. D.] CALTECH, Table Mt Facil, Jet Prop Lab, Wrightwood, CA 92397 USA. RP McDermid, IS (reprint author), CALTECH, Table Mt Facil, Jet Prop Lab, POB 367, Wrightwood, CA 92397 USA. EM mcdermid@tmf.jpl.nasa.gov FU JPL; TMF; California Institute of Technology; National Aeronautics and Space Administration FX The work described in this paper was carried out at The JPL, TMF, California Institute of Technology, under an agreement with the National Aeronautics and Space Administration. The authors are grateful to T. McGee, G. Sumnicht, and L. Twigg for the use of lidar campaign data. NR 15 TC 5 Z9 5 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 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD SEP PY 2008 VL 79 IS 9 AR 094502 DI 10.1063/1.2976672 PG 9 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 363UG UT WOS:000260291800044 PM 19044439 ER PT J AU Klaasen, KP A'Hearn, MF Baca, M Delamere, A Desnoyer, M Farnham, T Groussin, O Hampton, D Ipatov, S Li, JY Lisse, C Mastrodemos, N McLaughlin, S Sunshine, J Thomas, P Wellnitz, D AF Klaasen, Kenneth P. A'Hearn, Michael F. Baca, Michael Delamere, Alan Desnoyer, Mark Farnham, Tony Groussin, Olivier Hampton, Donald Ipatov, Sergei Li, Jianyang Lisse, Carey Mastrodemos, Nickolaos McLaughlin, Stephanie Sunshine, Jessica Thomas, Peter Wellnitz, Dennis TI Invited Article: Deep Impact instrument calibration SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID MISSION; CATALOG; IMAGES AB Calibration of NASA's Deep Impact spacecraft instruments allows reliable scientific interpretation of the images and spectra returned from comet Tempel 1. Calibrations of the four onboard remote sensing imaging instruments have been performed in the areas of geometric calibration, spatial resolution, spectral resolution, and radiometric response. Error sources such as noise (random, coherent, encoding, data compression), detector readout artifacts, scattered light, and radiation interactions have been quantified. The point spread functions (PSFs) of the medium resolution instrument and its twin impactor targeting sensor are near the theoretical minimum [similar to 1.7 pixels full width at half maximum (FWHM)]. However, the high resolution instrument camera was found to be out of focus with a PSF FWHM of similar to 9 pixels. The charge coupled device (CCD) read noise is similar to 1 DN. Electrical cross-talk between the CCD detector quadrants is correctable to <2 DN. The IR spectrometer response nonlinearity is correctable to similar to 1%. Spectrometer read noise is similar to 2 DN. The variation in zero-exposure signal level with time and spectrometer temperature is not fully characterized; currently corrections are good to similar to 10 DN at best. Wavelength mapping onto the detector is known within 1 pixel; spectral lines have a FWHM of similar to 2 pixels. About 1% of the IR detector pixels behave badly and remain uncalibrated. The spectrometer exhibits a faint ghost image from reflection off a beamsplitter. Instrument absolute radiometric calibration accuracies were determined generally to <10% using star imaging. Flat-field calibration reduces pixel-to-pixel response differences to similar to 0.5% for the cameras and similar to 2% for the spectrometer. A standard calibration image processing pipeline is used to produce archival image files for analysis by researchers. (C) 2008 American Institute of Physics. [DOI: 10.1063/1.2972112] C1 [Klaasen, Kenneth P.; Mastrodemos, Nickolaos] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [A'Hearn, Michael F.; Farnham, Tony; Groussin, Olivier; Ipatov, Sergei; Li, Jianyang; McLaughlin, Stephanie; Sunshine, Jessica; Wellnitz, Dennis] Univ Maryland, Dept Astron, College Pk, MD 20742 USA. [Baca, Michael] Sci Applicat Int Corp, Chantilly, VA 20151 USA. [Delamere, Alan] Delamere Support Serv, Boulder, CO 80304 USA. [Desnoyer, Mark; Thomas, Peter] Cornell Univ, Ithaca, NY 14853 USA. [Hampton, Donald] Ball Aerosp & Technol, Boulder, CO 80301 USA. [Lisse, Carey] Johns Hopkins Univ, Appl Phys Lab, SD SRE, Laurel, MD 20723 USA. RP Klaasen, KP (reprint author), CALTECH, Jet Prop Lab, Mail Stop 306-392,4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM kenneth.p.klaasen@jpl.nasa.gov; ma@astro.umd.edu; michael.w.baca@saic.com; alan@delamere.biz; md246@cornell.edu; farnham@astro.umd.edu; groussin@astro.umd.edu; donhampton@earthlink.net; ipatov@astro.umd.edu; jyli@astro.umd.edu; carey.lisse@jhuapl.edu; Nickolaos.Mastrodemos@jpl.nasa.gov; jyli@astro.umd.edu; stefmcl@astro.umd.edu; thomas@baritone.astro.cornell.edu; wellnitz@astro.umd.edu RI Wellnitz, Dennis/B-4080-2012; Lisse, Carey/B-7772-2016; Ipatov, Sergei/O-2302-2014 OI Lisse, Carey/0000-0002-9548-1526; Ipatov, Sergei/0000-0002-1413-9180 FU National Aeronautics and Space Administration [NASW00004]; Discovery Program to the University of Maryland [NMO710389]; Discovery Program to the Jet Propulsion Laboratory; California Institute of Technology FX The work described herein was supported by the National Aeronautics and Space Administration through Contract No. NASW00004 from the Discovery Program to the University of Maryland and through Task Order No. NMO710389 from the Discovery Program to the Jet Propulsion Laboratory, California Institute of Technology. We appreciate the contributions of James Baer, Ivo Busko, Lucas Kamp, Donald Lindler, Helen Mortensen, and William Owen to various aspects of this work. Figures 1-5, 56, and 71 reproduced from Ref. 3 with kind permission from Springer Science+Business Media. NR 26 TC 24 Z9 24 U1 1 U2 3 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 SEP PY 2008 VL 79 IS 9 AR 091301 DI 10.1063/1.2972112 PG 77 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 363UG UT WOS:000260291800001 PM 19044397 ER PT J AU Schaefer, RT MacAskill, JA Mojarradi, M Chutjian, A Darrach, MR Madzunkov, SM Shortt, BJ AF Schaefer, R. T. MacAskill, J. A. Mojarradi, M. Chutjian, A. Darrach, M. R. Madzunkov, S. M. Shortt, B. J. TI Digitally synthesized high purity, high-voltage radio frequency drive electronics for mass spectrometry SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID NONLINEAR ION-TRAP; HIGH-RESOLUTION; MINIATURE AB Reported herein is development of a quadrupole mass spectrometer controller (MSC) with integrated radio frequency (rf) power supply and mass spectrometer drive electronics. Advances have been made in terms of the physical size and power consumption of the MSC, while simultaneously making improvements in frequency stability, total harmonic distortion, and spectral purity. The rf power supply portion of the MSC is based on a series-resonant LC tank, where the capacitive load is the mass spectrometer itself, and the inductor is a solenoid or toroid, with various core materials. The MSC drive electronics is based on a field programmable gate array (FPGA), with serial peripheral interface for analog-to-digital and digital-to-analog converter support, and RS232/RS422 communications interfaces. The MSC offers spectral quality comparable to, or exceeding, that of conventional rf power supplies used in commercially available mass spectrometers; and as well an inherent flexibility, via the FPGA implementation, for a variety of tasks that includes proportional-integral derivative closed-loop feedback and control of rf, rf amplitude, and mass spectrometer sensitivity. Also provided are dc offsets and resonant dipole excitation for mass selective accumulation in applications involving quadrupole ion traps; rf phase locking and phase shifting for external loading of a quadrupole ion trap; and multichannel scaling of acquired mass spectra. The functionality of the MSC is task specific, and is easily modified by simply loading FPGA registers or reprogramming FPGA firmware. (C) 2008 American Institute of Physics. [DOI: 10.1063/1.2981691] C1 [Schaefer, R. T.; Mojarradi, M.] CALTECH, Jet Prop Lab, Adv Comp Syst & Technol Grp, Pasadena, CA 91109 USA. [MacAskill, J. A.; Chutjian, A.; Darrach, M. R.; Madzunkov, S. M.] CALTECH, Jet Prop Lab, Atom & Mol Phys Grp, Pasadena, CA 91109 USA. [Shortt, B. J.] Astrium Satellites Ltd, Stevenage SG1 2AS, Herts, England. RP Schaefer, RT (reprint author), CALTECH, Jet Prop Lab, Adv Comp Syst & Technol Grp, Pasadena, CA 91109 USA. FU National Aeronautics and Space Administration; National Science Foundation [PHY-0441183] FX This work was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under the contract with the National Aeronautics and Space Administration. It was also supported in part by the National Science Foundation under grant PHY-0441183. NR 12 TC 4 Z9 4 U1 2 U2 7 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 SEP PY 2008 VL 79 IS 9 AR 095107 DI 10.1063/1.2981691 PG 6 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 363UG UT WOS:000260291800059 PM 19044454 ER PT J AU Cameron, R Gizon, L Duvall, TL AF Cameron, R. Gizon, L. Duvall, T. L., Jr. TI Helioseismology of sunspots: Confronting observations with three-dimensional MHD simulations of wave propagation SO SOLAR PHYSICS LA English DT Article; Proceedings Paper CT International Conference on Helioseismology, Asteroseismology and MHD Connections (HELAS II) CY AUG 20-24, 2007-2008 CL Gottingen, GERMANY DE Sun : helioseismology; Sun : sunspots; Sun : magnetic fields ID TIME-DISTANCE HELIOSEISMOLOGY; VERTICAL MAGNETIC-FIELD; SOLAR ACTIVE REGIONS; P-MODES; FLUX TUBES; ABSORPTION; OSCILLATIONS; SCATTERING; CONVERSION; INVERSION AB The propagation of solar waves through the sunspot of AR 9787 is observed by using temporal cross-correlations of SOHO/MDI Dopplergrams. We then use three-dimensional MHD numerical simulations to compute the propagation of wave packets through self-similar magnetohydrostatic sunspot models. The simulations are set up in such a way as to allow a comparison with observed cross-covariances (except in the immediate vicinity of the sunspot). We find that the simulation and the f-mode observations are in good agreement when the model sunspot has a peak field strength of 3 kG at the photosphere and less so for lower field strengths. Constraining the sunspot model with helioseismology is only possible because the direct effect of the magnetic field on the waves has been fully taken into account. Our work shows that the full-waveform modeling of sunspots is feasible. C1 [Cameron, R.; Gizon, L.] Max Planck Inst Sonnensyst Forsch, D-37191 Katlenburg Lindau, Germany. [Duvall, T. L., Jr.] NASA Goddard Space Flight Ctr, Solar Phys Lab, Greenbelt, MD 20771 USA. RP Cameron, R (reprint author), Max Planck Inst Sonnensyst Forsch, D-37191 Katlenburg Lindau, Germany. EM cameron@mps.mpg.de RI Gizon, Laurent/B-9457-2008; Duvall, Thomas/C-9998-2012 NR 39 TC 70 Z9 70 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 SEP PY 2008 VL 251 IS 1-2 BP 291 EP 308 DI 10.1007/s11207-008-9148-1 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 340PS UT WOS:000258658100021 ER PT J AU Hirzberger, J Gizon, L Solanki, SK Duvall, TL AF Hirzberger, Johann Gizon, Laurent Solanki, Sami K. Duvall, Thomas L., Jr. TI Structure and evolution of supergranulation from local helioseismology SO SOLAR PHYSICS LA English DT Article; Proceedings Paper CT International Conference on Helioseismology, Asteroseismology and MHD Connections (HELAS II) CY AUG 20-24, 2007-2008 CL Gottingen, GERMANY DE sun : supergranulation; sun : photosphere; helioseismology ID TIME-DISTANCE HELIOSEISMOLOGY; LARGE-SCALE MOTIONS; SOLAR GRANULATION; VELOCITY-FIELDS; CHROMOSPHERIC NETWORK; MAGNETIC FIELDS; MESOGRANULATION; GRANULES; SURFACE; SIZES AB Supergranulation is visible at the solar surface as a cellular pattern of horizontal outflows. Although it does not show a distinct intensity pattern, it manifests itself indirectly in, for example, the chromospheric network. Previous studies have reported significant differences in the inferred basic parameters of the supergranulation phenomenon. Here we study the structure and temporal evolution of a large sample of supergranules, measured by using local helioseismology and SOHO/MDI data from the year 2000 at solar activity minimum. Local helioseismology with f modes provides maps of the horizontal divergence of the flow velocity at a depth of about 1 Mm. From these divergence maps supergranular cells were identified by using Fourier segmentation procedures in two dimensions and in three dimensions (two spatial dimensions plus time). The maps that we analyzed contain more than 10(5) supergranular cells and more than 10(3) lifetime histories, which makes possible a detailed analysis with high statistical significance. We find that the supergranular cells have a mean diameter of 27.1 Mm. The mean lifetime is estimated to be 1.6 days from the measured distribution of lifetimes (three-dimensional segmentation), with a clear tendency for larger cells to live longer than smaller ones. The pair and mark correlation functions do not show pronounced features on scales larger than the typical cell size, which suggests purely random cell positions. The temporal histories of supergranular cells indicate a smooth evolution from their emergence and growth in the first half of their lives to their decay in the second half of their lives (unlike exploding granules, which reach their maximum size just before they fragment). C1 [Hirzberger, Johann; Gizon, Laurent; Solanki, Sami K.] Max Planck Inst Sonnensyst Forsch, D-37191 Katlenburg Lindau, Germany. [Duvall, Thomas L., Jr.] NASA, Goddard Space Flight Ctr, Lab Solar & Space Phys, Greenbelt, MD 20771 USA. RP Hirzberger, J (reprint author), Max Planck Inst Sonnensyst Forsch, D-37191 Katlenburg Lindau, Germany. EM hirzberger@mps.mpg.de RI Gizon, Laurent/B-9457-2008; Duvall, Thomas/C-9998-2012; Solanki, Sami/E-2487-2013 OI Solanki, Sami/0000-0002-3418-8449 NR 44 TC 29 Z9 29 U1 1 U2 1 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-0938 J9 SOL PHYS JI Sol. Phys. PD SEP PY 2008 VL 251 IS 1-2 BP 417 EP 437 DI 10.1007/s11207-008-9206-8 PG 21 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 340PS UT WOS:000258658100028 ER PT J AU Johnson, SW Thedinga, JF Munk, KM AF Johnson, Scotr W. Thedinga, John F. Munk, Kristen M. TI Distribution and Use of Shallow-Water Habitats by Pacific Sand Lances in Southeastern Alaska SO TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY LA English DT Article ID AMMODYTES-HEXAPTERUS; FISH COMMUNITIES AB The Pacific sand lance Ammodytes hexapterus is an important prey species, but little is known about its distribution and habitat use, especially among early life stages in southeastern Alaska. To address this information need, we examined the distribution and habitat use of Pacific sand lances by sampling a variety of shallow-water habitats (depth < 6 m) with a beach seine seasonally throughout southeastern Alaska from 1998 to 2006. An estimated 81,939 Pacific sand lances were captured at 31 of 49 locations and in 109 of 610 seine hauls. Total catch and percent frequency of occurrence (FO; [number of seine hauls with Pacific sand lances/total number of hauls] x 100) was greatest in summer (73,033 fish, FO = 2 1 %), followed by spring (8,857 fish, 18%) and winter (49 fish, 1%). Pacific sand lances were captured in all habitat types; total catch in spring ranged from 16 fish in understory kelp (e.g., Laminariales) to 8,525 fish in bedrock outcrops, whereas total catch in summer ranged from 5,858 fish in sand to 54,851 fish in eelgrass Zostera marina. The FO was relatively consistent among the above habitat types and ranged from 15% to 20% in spring and from 15% to 35% in summer. Pacific sand lances use a variety of shallow-water habitats for at least 4 months in spring and summer; habitat is not limited to sandy substrates for burrowing but also includes bedrock, eelgrass, and kelp as likely foraging areas. Age-1 and younger Pacific sand lances dominated our catches; size range of captured fish was 39-168 mm fork length. The importance of Pacific sand lances in the diets of other fishes, seabirds, and marine mammals justifies the need to better understand, protect, and manage habitats that are essential to Pacific sand lances. C1 [Johnson, Scotr W.; Thedinga, John F.] NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Auke Bay Labs, Juneau, AK 99801 USA. [Munk, Kristen M.] Alaska Dept Fish & Game, Mark Tag & Age Lab, Age Determinat Unit, Juneau, AK 99802 USA. RP Johnson, SW (reprint author), NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Auke Bay Labs, 17109 Point Lena Loop Rd, Juneau, AK 99801 USA. EM scott.johnson@noaa.gov NR 35 TC 4 Z9 4 U1 0 U2 6 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE SUITE 110, BETHESDA, MD 20814-2199 USA SN 0002-8487 J9 T AM FISH SOC JI Trans. Am. Fish. Soc. PD SEP PY 2008 VL 137 IS 5 BP 1455 EP 1463 DI 10.1577/T07-194.1 PG 9 WC Fisheries SC Fisheries GA 369OR UT WOS:000260704300017 ER PT J AU Mustafa, T AF Mustafa, Tariq TI Development of objective criteria to evaluate the authenticity of revelation SO ZYGON LA English DT Article DE authentic revelation; Creator; evaluative framework; falsifiable statements; logical criteria; rational evidence; reason; revelation; SETI project; unfavorable side effects of science AB Science has been dazzlingly successful in explaining nature. Scientific advances also have led to certain undesirable, though unintended, side effects, one of which is alienation from the spiritual. Revelation comes from the Divine. But what is the status of authenticity of a particular piece claimed to be revelation? What is its historical validity and current state of preservation ? This essay proposes to develop a list of rational criteria, in consultation with all stakeholders, for addressing the subject. The aim is to bring objectivity into this discourse by placing it more on the turf of reason rather than basing it on considerations of faith and prior allegiance. C1 [Mustafa, Tariq] USAEC, Oak Ridge, TN USA. [Mustafa, Tariq] NASA, Wallops Isl, VA USA. RP Mustafa, T (reprint author), USAEC, Oak Ridge, TN USA. EM mustafatariq@hotmail.com NR 1 TC 0 Z9 0 U1 0 U2 0 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0591-2385 J9 ZYGON JI Zygon PD SEP PY 2008 VL 43 IS 3 BP 737 EP 744 DI 10.1111/j.1467-9744.2008.00951.x PG 8 WC Social Issues; Religion SC Social Issues; Religion GA 341RU UT WOS:000258733300016 ER PT J AU Liu, D Wang, Z Liu, ZY Winker, D Trepte, C AF Liu, Dong Wang, Zhien Liu, Zhaoyan Winker, Dave Trepte, Charles TI A height resolved global view of dust aerosols from the first year CALIPSO lidar measurements SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID LONG-RANGE TRANSPORT; NORTH-ATLANTIC OCEAN; ASIAN DUST; SAHARAN DUST; MINERAL DUST; APRIL 1998; SOIL DUST; ULTRAVIOLET-RADIATION; ATMOSPHERIC TRANSPORT; TIBETAN PLATEAU AB Based on the first year of CALIPSO lidar measurements under cloud-free conditions, a height-resolved global distribution of dust aerosols is presented for the first time. Results indicate that spring is the most active dust season, during which similar to 20% and similar to 12% of areas between 0 and 60 degrees N are influenced by dust at least 10% and 50% of the time, respectively. In summer within 3-6 km, similar to 8.3% of area between 0 and 60 degrees N is impacted by dust at least 50% of the time. Strong seasonal cycles of dust layer vertical extent are observed in major source regions, which are similar to the seasonal variation of the thermally driven boundary layer depth. The arid and semiarid areas in North Africa and the Arabian Peninsula are the most persistent and prolific dust sources. African dust is transported across the Atlantic all yearlong with strong seasonal variation in the transport pathways mainly in the free troposphere in summer and at the low altitudes in winter. However, the trans-Atlantic dust is transported at the low altitudes is important for all seasons, especially transported further cross the ocean. The crossing Atlantic dusty zones are shifted southward from summer to winter, which is accompanied by a similar southward shift of dust-generating areas over North Africa. The Taklimakan and Gobi deserts are two major dust sources in East Asia with long-range transport mainly occurring in spring. The large horizontal and vertical coverage of dust aerosols indicate their importance in the climate system through both direct and indirect aerosol effects. C1 [Liu, Dong; Wang, Zhien] Univ Wyoming, Dept Atmospher Sci, Laramie, WY 82071 USA. [Liu, Zhaoyan] Natl Inst Aerosp, Hampton, VA 23666 USA. [Winker, Dave; Trepte, Charles] NASA, Langley Res Ctr, Hampton, VA 23681 USA. [Liu, Dong] Chinese Acad Sci, Hefei Inst Phys Sci, Hefei, Anhui, Peoples R China. RP Liu, D (reprint author), Univ Wyoming, Dept Atmospher Sci, Dept 3038,1000E Univ Ave, Laramie, WY 82071 USA. EM dliu3@uwyo.edu RI Liu, Zhaoyan/A-9604-2009; Liu, Zhaoyan/B-1783-2010; Wang, Zhien/F-4857-2011 OI Liu, Zhaoyan/0000-0003-4996-5738; FU NASA/JPL; NASA/LARC FX This analysis is supported by the CloudSat project from NASA/JPL and CALIPSO project from NASA/LARC. The authors would like to acknowledge three anonymous reviewers for their constructive comments. NR 61 TC 107 Z9 112 U1 5 U2 28 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 AUG 30 PY 2008 VL 113 IS D16 AR D16214 DI 10.1029/2007JD009776 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 342ZN UT WOS:000258822200003 ER PT J AU Chen, SH Moore, TE AF Chen, Sheng-Hsien Moore, Thomas E. TI Ionospheric ions in the near-Earth magnetotail SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID HIGH-LATITUDE; GEOTAIL; PLASMA; MAGNETOPAUSE; DENSITY; FIELD; LOBE; MAGNETOSPHERE; TEMPERATURE; SUBSTORM AB We report studies of the relationship between geomagnetic storms and the spatial distribution of cold ions, mostly of ionospheric origin, in the near-Earth magnetotail using in situ particle and field measurements from the Polar spacecraft, solar wind measurements from the ACE spacecraft, and ground geomagnetic indices, during the years from 2000 to 2005. We find local time and latitude-dependent distributions of the plasma moments of cold ions at various levels of geomagnetic storms characterized by the Sym-H and Dst indices. (1) Denser cold ions were observed at the duskside (N > 10 cm(-3) compared with 1 cm(-3) on average): consistent with the formation of plasma plumes and enhanced bulge region formed as the cold ions wrapped under corotation. (2) Higher temperatures were observed in the auroral oval regions, and a larger temperature anisotropy was observed at the dawnside. (3) Heating processes were strongest near midnight and in the auroral oval regions, which map to PSBL or CPS, except during extremely high geomagnetic activity levels, when heating occurred at high latitudes toward the dawnside, which map to the plasma mantle or distant magnetotail. We interpret these variations as results of ionospheric outflows and plasmaspheric expansion interacting with enhancements of near-Earth magnetospheric convection and geomagnetic-storm-related heating processes in the magnetotail. C1 [Chen, Sheng-Hsien] NASA, Goddard Space Flight Ctr, Geospace Phys Lab, Greenbelt, MD 20771 USA. [Chen, Sheng-Hsien] NASA, Goddard Space Flight Ctr, Geospace Phys Lab, Heliophys Sci Div,USRA, Greenbelt, MD 20771 USA. RP Chen, SH (reprint author), NASA, Goddard Space Flight Ctr, Geospace Phys Lab, Greenbelt, MD 20771 USA. EM sheng-hsien.chen@gsfc.nasa.gov RI Moore, Thomas/D-4675-2012 OI Moore, Thomas/0000-0002-3150-1137 FU NASA [WBS 889836.04.05] FX The authors thank C. T. Russell of IGPP/UCLA for providing Polar magnetic field data, Space Physics Data Facility of NASA Goddard Space Flight Center for providing ACE plasma and magnetic field data, and Kyoto University World Data Center for providing Sym-H and Dst indices. This work was supported by the NASA Polar-Wind-Geotail project under WBS 889836.04.05. NR 37 TC 1 Z9 1 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 AUG 30 PY 2008 VL 113 IS A8 AR A08232 DI 10.1029/2007JA012816 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 343AO UT WOS:000258824900001 ER PT J AU Alkhaled, AA Michalak, AM Kawa, SR AF Alkhaled, A. A. Michalak, A. M. Kawa, S. R. TI Using CO2 spatial variability to quantify representation errors of satellite CO2 retrievals SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID INVERSIONS AB Satellite measurements of column-averaged CO2 dry-air mole fraction (X-CO2) will be used in inversion and data assimilation studies to improve the precision and resolution of current estimates of global fluxes of CO2. Representation errors due to the mismatch in spatial scale between satellite retrievals and atmospheric transport models contribute to the uncertainty associated with flux estimates. This study presents a statistical method for quantifying representation errors as a function of the underlying spatial variability of X-CO2 and the spatial distribution of retrieved soundings, without knowledge of the true X-CO2 distribution within model gridcells. Representation errors are quantified globally using regional XCO2 spatial variability inferred using the PCTM/GEOS-4 model and a hypothetical atmospheric transport model with 1 degrees x 1 degrees resolution, 3 km(2) retrieval footprints, and two different sounding densities. C1 [Alkhaled, A. A.; Michalak, A. M.] Univ Michigan, Dept Civil & Environm Engn, Ann Arbor, MI 48109 USA. [Michalak, A. M.] Univ Michigan, Dept Atmospher Ocean & Space Sci, Ann Arbor, MI 48109 USA. [Kawa, S. R.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Alkhaled, AA (reprint author), Univ Michigan, Dept Civil & Environm Engn, 183 EWRE Bldg, Ann Arbor, MI 48109 USA. RI Kawa, Stephan/E-9040-2012 FU NASA; NASA [NNX08AJ92G]; Kuwait University Scholarship Committee; NASA Carbon Cycle Science FX This research was partially performed for the Orbiting Carbon Observatory Project at Caltech-JPL, under a contract with NASA. Additional support was provided through NASA grant NNX08AJ92G, and the Kuwait University Scholarship Committee. The PCTM work was enabled by G. J. Collatz and Z. Zhu, and supported by NASA Carbon Cycle Science. NR 15 TC 5 Z9 5 U1 0 U2 8 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 AUG 29 PY 2008 VL 35 IS 16 AR L16813 DI 10.1029/2008GL034528 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 342YV UT WOS:000258820400001 ER PT J AU Hulley, GC Hook, SJ AF Hulley, G. C. Hook, S. J. TI A new methodology for cloud detection and classification with ASTER data SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID CLEAR-SKY AB High spatial resolution sensors such as Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) have the potential to produce gridded, large area datasets of surface parameters such as elevation and emissivity. These datasets are typically derived by combining all clear-sky pixels over a given location for a specified time period necessitating the use of an automated cloud detection and classification algorithm. The current ASTER L1A cloud mask lacks several key features needed to use it for this purpose. We have developed a new cloud detection algorithm which addresses these limitations by using a 2-pass approach similar to Landsat-7 and including further spectral tests for cirrus and cloud shadows from MODIS. The new cloud detection methodology is described together with several case studies that highlight key aspects of the algorithm and comparisons with the MODIS and the current ASTER L1A cloud mask. C1 [Hulley, G. C.; Hook, S. J.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Hulley, GC (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM glynn.hulley@jpl.nasa.gov NR 9 TC 10 Z9 13 U1 0 U2 12 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 AUG 28 PY 2008 VL 35 IS 16 AR L16812 DI 10.1029/2008GL034644 PG 6 WC Geosciences, Multidisciplinary SC Geology GA 342YU UT WOS:000258820300003 ER PT J AU Morgenstern, O Braesicke, P Hurwitz, MM O'Connor, FM Bushell, AC Johnson, CE Pyle, JA AF Morgenstern, Olaf Braesicke, Peter Hurwitz, Margaret M. O'Connor, Fiona M. Bushell, Andrew C. Johnson, Colin E. Pyle, John A. TI The world avoided by the Montreal Protocol SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID HEMISPHERE CLIMATE-CHANGE; GAS-PHASE REACTIONS; ATMOSPHERIC CHEMISTRY; PHOTOCHEMICAL DATA; OZONE; STRATOSPHERE; MODEL; DEPLETION; DESTRUCTION; CIRCULATION AB The impact of increased stratospheric chlorine, averted by controls imposed by the Montreal Protocol, is studied using the UKCA chemistry-climate model. We contrast an atmosphere with 9 ppbv Cl-y, which could have occurred by similar to 2030, with the present-day loading (3.5 ppbv), and consider the response of climate to resulting ozone perturbations, disregarding the radiative impact of the additional CFCs. Ozone columns decline everywhere, with climate impacts in both polar regions. The additional chlorine leads to a strengthening of the Southern Annular Mode, versus the reference, and Antarctic surface temperature differences resemble observed changes. Over Eurasia, winter surface temperature changes project on the Northern Annular Mode. These high-latitude temperature perturbations (> 1 K) are larger than the global mean temperature rises projected over the next few decades, and perhaps comparable with projected regional changes. The Montreal Protocol has not only averted further damage to the ozone layer but has helped prevent significant regional climate change. C1 [Morgenstern, Olaf; Braesicke, Peter; Pyle, John A.] Univ Cambridge, Dept Chem, NCAS Climate Chem, Ctr Atmospher Sci, Cambridge CB2 1EW, England. [O'Connor, Fiona M.; Johnson, Colin E.] Met Off, Hadley Ctr, Exeter EX1 3PB, Devon, England. [Hurwitz, Margaret M.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Morgenstern, O (reprint author), Univ Cambridge, Dept Chem, NCAS Climate Chem, Ctr Atmospher Sci, Lensfield Rd, Cambridge CB2 1EW, England. EM morgenstern@atm.ch.cam.ac.uk RI Braesicke, Peter/D-8330-2016; OI Braesicke, Peter/0000-0003-1423-0619; Morgenstern, Olaf/0000-0002-9967-9740 FU NERC National Centre for Atmospheric Science; European Commission FX This work was supported by the NERC National Centre for Atmospheric Science and by the European Commission through the SCOUT-O3 project. NR 38 TC 42 Z9 43 U1 3 U2 12 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 AUG 28 PY 2008 VL 35 IS 16 AR L16811 DI 10.1029/2008GL034590 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 342YU UT WOS:000258820300002 ER PT J AU Wang, DY Huo, WM AF Wang, Dunyou Huo, Winifred M. TI An eight-degree-of-freedom quantum dynamics study of the isotopic effect on the reaction: HD+C(2)H SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID RATE-CONSTANT MEASUREMENTS; TEMPERATURE-DEPENDENCE; C2H; SCATTERING; H-2; PHOTOCHEMISTRY; ACETYLENE; D2; ATMOSPHERE; KINETICS AB An eight-dimensional time-dependent quantum dynamics calculation is reported to study the isotopic reaction, HD+C(2)H, on a new modified potential energy surface. Initial-state-selected reaction probability, integral cross section, and rate constants are presented in this isotopic reaction study. Initial-state-selected reaction probability is obtained by summing over all the possible product's arrangements in this isotopic reaction study. This study shows that vibrational excitations of HD enhance the reactivity, whereas stretching excitations of C(2)H only have a small effect on the reactivity. Furthermore, the bending excitations of C(2)H, compared to the ground-state reaction probability, hinder the reactivity. The present results are consistent with those obtained for the H(2)+C(2)H reaction. The comparison of these two reactions also shows the isotopic effect in the initial-state-selected reaction probability, integral cross section, and rate constants. The rate constant comparison shows that the HD+C(2)H reaction has a smaller reactivity than the H(2)+C(2)H reaction. (c) 2008 American Institute of Physics. C1 [Wang, Dunyou] Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. [Huo, Winifred M.] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Wang, DY (reprint author), Pacific NW Natl Lab, Environm Mol Sci Lab, MS-IN-K8-91,POB 999, Richland, WA 99352 USA. EM dunyou.wang@pnl.gov FU Department of Energy by Battelle [DE-AC05-76RL01830] FX The author thanks Dr. Ke-Li Han for sending the new modified PES. Pacific Northwest National Laboratory is operated for the Department of Energy by Battelle under Contract No. DE-AC05-76RL01830. NR 36 TC 10 Z9 10 U1 0 U2 5 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD AUG 28 PY 2008 VL 129 IS 8 AR 084303 DI 10.1063/1.2971184 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 345PO UT WOS:000259008900011 PM 19044819 ER PT J AU Lamsal, LN Martin, RV van Donkelaar, A Steinbacher, M Celarier, EA Bucsela, E Dunlea, EJ Pinto, JP AF Lamsal, L. N. Martin, R. V. van Donkelaar, A. Steinbacher, M. Celarier, E. A. Bucsela, E. Dunlea, E. J. Pinto, J. P. TI Ground-level nitrogen dioxide concentrations inferred from the satellite-borne Ozone Monitoring Instrument SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SOUTHERN CALIFORNIA CHILDREN; POLLUTED URBAN-ENVIRONMENT; LUNG-FUNCTION GROWTH; PHOTOSTATIONARY STATE; AIR-POLLUTANTS; NOX EMISSIONS; MCMA-2003 CAMPAIGN; MODEL DESCRIPTION; REGIONAL BUDGETS; NORTH-AMERICA AB We present an approach to infer ground-level nitrogen dioxide (NO2) concentrations by applying local scaling factors from a global three-dimensional model (GEOS-Chem) to tropospheric NO2 columns retrieved from the Ozone Monitoring Instrument (OMI) onboard the Aura satellite. Seasonal mean OMI surface NO2 derived from the standard tropospheric NO2 data product (Version 1.0.5, Collection 3) varies by more than two orders of magnitude (< 0.1-> 10 ppbv) over North America. Two ground-based data sets are used to validate the surface NO2 estimate and indirectly validate the OMI tropospheric NO2 retrieval: photochemical steady-state (PSS) calculations of NO2 based on in situ NO and O-3 measurements, and measurements from a commercial chemiluminescent NO2 analyzer equipped with a molybdenum converter. An interference correction algorithm for the latter is developed using laboratory and field measurements and applied using modeled concentrations of the interfering species. The OMI-derived surface NO2 mixing ratios are compared with an in situ surface NO2 data obtained from the U. S. Environmental Protection Agency's Air Quality System (AQS) and Environment Canada's National Air Pollution Surveillance (NAPS) network for 2005 after correcting for the interference in the in situ data. The overall agreement of the OMI-derived surface NO2 with the corrected in situ measurements and PSS-NO2 is -11-36%. A larger difference in winter/spring than in summer/fall implies a seasonal bias in the OMI NO2 retrieval. The correlation between the OMI-derived surface NO2 and the ground-based measurements is significant (correlation coefficient up to 0.86) with a tendency for higher correlations in polluted areas. The satellite-derived data base of ground level NO2 concentrations could be valuable for assessing exposures of humans and vegetation to NO2, supplementing the capabilities of the ground-based networks, and evaluating air quality models and the effectiveness of air quality control strategies. C1 [Lamsal, L. N.; Martin, R. V.; van Donkelaar, A.] Dalhousie Univ, Dept Phys & Atmospher Sci, Halifax, NS B3H 3J5, Canada. [Martin, R. V.] Smithsonian Astrophys Observ, Harvard Smithsonian Ctr Astrophys, Atom & Mol Phys Div, Cambridge, MA USA. [Steinbacher, M.] Empa, Swiss Fed Labs Mat Testing & Res, Swiss Fed Inst Mat Sci & Technol, Lab Air Pollut Environm Technol, CH-8600 Dubendorf, Switzerland. [Celarier, E. A.] NASA, Goddard Space Flight Ctr, SGT Inc, Greenbelt, MD 20770 USA. [Dunlea, E. J.] MIT, Dept Earth Atmospher & Planetary Sci, Cambridge, MA USA. [Pinto, J. P.] US EPA, Natl Ctr Environm Assessment, Res Triangle Pk, NC 27711 USA. RP Lamsal, LN (reprint author), Dalhousie Univ, Dept Phys & Atmospher Sci, James Dunn Bldg,Room 102, Halifax, NS B3H 3J5, Canada. EM lok.lamsal@fizz.phys.dal.ca; randall.martin@dal.ca; aaron.van.donkelaar@dal.ca; martin.steinbacher@empa.ch; edward.a.celarier@nasa.gov; bucsela@ix.netcom.com; edward.dunlea@colorado.edu; pinto.joseph@epamail.epa.gov RI Steinbacher, Martin/B-7424-2009; Lamsal, Lok/G-4781-2012; Martin, Randall/C-1205-2014; Chem, GEOS/C-5595-2014 OI Steinbacher, Martin/0000-0002-7195-8115; Martin, Randall/0000-0003-2632-8402; FU NASA; Natural Sciences and Engineering Research Council of Canada; Comision Ambiental Metropolitana (Mexico); National Science Foundation [ATM-308748, ATM-0528170, ATM-0528227]; Department of Energy [DE-FG02-05ER63980, DE-FG02-05ER63982] FX We thank Ron Cohen and three anonymous reviewers for helpful comments that improved the manuscript. We are grateful to Michel Grutter, Armando Retama, and C. R. Ramos Villegas for their DOAS and NOx monitor data for Mexico City. We thank the OMI, AQS, and NAPS teams for making the data available. This work was supported by NASA's Atmospheric Composition Program and the Natural Sciences and Engineering Research Council of Canada. For the MCMA field campaign, the leadership of Mario and Luisa Molina and financial support from Comision Ambiental Metropolitana (Mexico), the National Science Foundation (ATM-308748, ATM-0528170, and ATM-0528227), and the Department of Energy (DE-FG02-05ER63980 and DE-FG02-05ER63982) are gratefully acknowledged. This paper has been reviewed in accordance with the U.S. Environmental Protection Agency(tm)s (EPA) peer and administrative review policies and is approved for publication. The views expressed herein are solely those of the authors and do not represent the official policies or positions of the U.S. EPA. NR 89 TC 99 Z9 101 U1 3 U2 44 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 AUG 28 PY 2008 VL 113 IS D16 AR D16308 DI 10.1029/2007JD009235 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 342ZJ UT WOS:000258821800001 ER PT J AU Haider, SA Sheel, V Singh, V Maguire, WC Molina-Cuberos, GJ AF Haider, S. A. Sheel, Varun Singh, V. Maguire, W. C. Molina-Cuberos, G. J. TI Model calculation of production rates, ion and electron densities in the evening troposphere of Mars at latitudes 67 degrees N and 62 degrees S: Seasonal variability SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID ULTRAVIOLET SPECTROMETER EXPERIMENT; MARTIAN ATMOSPHERE; MOLECULAR-OXYGEN; IONOSPHERE; NITROGEN; SURFACE AB We have developed a model to calculate the production rates and densities of positive and negative ions in the troposphere of Mars at evening. Using this model, the densities of 35 ions (A(r)(+), O(2)(+), CO(2)(+), O(2)(+)CO(2), NO(+), H(3)O(+), H(3)O(+)H(2)O, H(3)O(+)(H(2)O)(2), H(3)O(+)(H(2)O)(3), H(3)O(+)(H(2)O)(4), H(3)O(+) HO, CO(2)(+)CO(2), CO(+), C(+), N(2)(+), NO(+)CO(2), N(+), O(2)(+)(CO(2))(2), O(2)(+)H(2)O, O(2)(+)(H(2)O)(2), O(4)(+), O(+), CO(3)(-) H(2)O, CO(3)(-)(H(2)O)(2), CO(3)(-), CO(4)(-), NO(2)(-), NO(2)(-)H(2)O, NO(2)(-)(H(2)O)(2), NO(3)(-), NO(3)(-) H(2)O, NO(3)(-)(H(2)O)(2), O(2)(-), O(3)(-), O(-)) are estimated in summer and winter at latitudes 67 degrees N and 62 degrees S for solar zenith angles 80 degrees and 85 degrees, respectively. The impact ionization source is taken as galactic cosmic rays. The model atmospheres at these locations are constructed from air density measured by radio occultation experiment aboard Mars Global Surveyor. The maximum electron densities in southern winter and northern summer are obtained at altitudes similar to 25 km and similar to 30 km, respectively, due to high efficiency of electron attachment to Ox molecules. Of the 35 ions considered in the model, the chemistry of 9 major ions (H(3)O+(H(2)O) n for n = 1, 2, 3, 4 and CO(4)(-), CO(3)(-), NO(2)(-)H(2)O and CO(3)(-)(H(2)O)(n) for n = 1, 2) are discussed in this paper. The ion densities are changed by factors of 5 to 10 between these two seasons. C1 [Haider, S. A.; Sheel, Varun] Phys Res Lab, Dept Space & Atmospher Sci, Ahmadabad 380009, Gujarat, India. [Maguire, W. C.] NASA, Goddard Space Flight Ctr, Solar Syst Explorat Div, Greenbelt, MD 20771 USA. [Molina-Cuberos, G. J.] Univ Murcia, Fac Quim, Dept Fis, E-30100 Murcia, Spain. [Singh, V.] Univ Brescia, Dept Elect Automat, Fac Engn, I-25123 Brescia, Italy. RP Haider, SA (reprint author), Phys Res Lab, Dept Space & Atmospher Sci, Ahmadabad 380009, Gujarat, India. EM haider@prl.res.in RI Molina-Cuberos, Gregorio /K-7522-2014 OI Molina-Cuberos, Gregorio /0000-0002-5664-7028 NR 41 TC 9 Z9 9 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 AUG 28 PY 2008 VL 113 IS A8 AR A08320 DI 10.1029/2007JA012980 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 343AN UT WOS:000258824800003 ER PT J AU Banerjee, RK Ashtekar, KD Helmy, TA Effat, MA Back, LH Khoury, SF AF Banerjee, Rupak K. Ashtekar, Koustubh D. Helmy, Tarek A. Effat, Mohamed A. Back, Lloyd H. Khoury, Saeb F. TI Hemodynamic diagnostics of epicardial coronary stenoses: in-vitro experimental and computational study SO BIOMEDICAL ENGINEERING ONLINE LA English DT Article ID FRACTIONAL FLOW RESERVE; PRESSURE-GRADIENT; ARTERY STENOSES; GUIDE-WIRE; ANGIOPLASTY; VELOCITY; HUMANS; CATHETERIZATION; SEVERITY; BLOOD AB Background: The severity of epicardial coronary stenosis can be assessed by invasive measurements of trans-stenotic pressure drop and flow. A pressure or flow sensor-tipped guidewire inserted across the coronary stenosis causes an overestimation in true trans-stenotic pressure drop and reduction in coronary flow. This may mask the true severity of coronary stenosis. In order to unmask the true severity of epicardial stenosis, we evaluate a diagnostic parameter, which is obtained from fundamental fluid dynamics principles. This experimental and numerical study focuses on the characterization of the diagnostic parameter, pressure drop coefficient, and also evaluates the pressure recovery downstream of stenoses. Methods: Three models of coronary stenosis namely, moderate, intermediate and severe stenosis, were manufactured and tested in the in-vitro set-up simulating the epicardial coronary network. The trans-stenotic pressure drop and flow distal to stenosis models were measured by non-invasive method, using external pressure and flow sensors, and by invasive method, following guidewire insertion across the stenosis. The viscous and momentum-change components of the pressure drop for various flow rates were evaluated from quadratic relation between pressure drop and flow. Finally, the pressure drop coefficient (CDP(e)) was calculated as the ratio of pressure drop and distal dynamic pressure. The pressure recovery factor (eta) was calculated as the ratio of pressure recovery coefficient and the area blockage. Results: The mean pressure drop-flow characteristics before and during guidewire insertion indicated that increasing stenosis causes a shift in dominance from viscous pressure to momentum forces. However, for intermediate (similar to 80%) area stenosis, which is between moderate (similar to 65%) and severe (similar to 90%) area stenoses, both losses were similar in magnitude. Therefore, guidewire insertion plays a critical role in evaluating the hemodynamic severity of coronary stenosis. More importantly, mean CDP(e) increased (17 +/- 3.3 to 287 +/- 52, n = 3, p < 0.01) and mean. decreased (0.54 +/- 0.04 to 0.37 +/- 0.05, p < 0.01) from moderate to severe stenosis during guidewire insertion. Conclusion: The wide range of CDP(e) is not affected that much by the presence of guidewire. CDP(e) can be used in clinical practice to evaluate the true severity of coronary stenosis due to its significant difference between values measured at moderate and severe stenoses. C1 [Banerjee, Rupak K.; Ashtekar, Koustubh D.] Univ Cincinnati, Dept Mech Ind & Nucl Engn, Cincinnati, OH 45221 USA. [Helmy, Tarek A.; Effat, Mohamed A.; Khoury, Saeb F.] Univ Cincinnati, Dept Internal Med Cardiol, MSB, Cincinnati, OH USA. [Back, Lloyd H.] CALTECH, Jet Prop Lab, Pasadena, CA USA. [Banerjee, Rupak K.] Dept Biomed Engn, Cincinnati, OH 45221 USA. RP Banerjee, RK (reprint author), Univ Cincinnati, Dept Mech Ind & Nucl Engn, 601B Rhodes Hall,Clifton Ave, Cincinnati, OH 45221 USA. EM rupak.banerjee@uc.edu; ashtekkd@email.uc.edu; tarek.helmy@uc.edu; mohamed.effat@uc.edu; rupak_ban@yahoo.com; saeb.khoury@uc.edu RI Helmy, Tarek/B-5967-2015 FU American Heart Association [0335270N] FX This work is supported by American Heart Association: National-Scientific Development Grant (# 0335270N). Authors would like to thank Dr. Bernard J. Dardzinski of Cincinnati Children's hospital, for providing the MicroCT facility used for the accurate dimensional measurements of the test sections. We are also grateful to Tristate cutting tool Inc, for manufacturing the stenosis test models to highest precision level. Authors want to acknowledge the help of Dr. Abhijit Sinha Roy during the experimental setup and test section design. We are thankful to all members of the Bio-Fluid, Heat, and Mass Transport Lab (Bio-FHM), Mr. Doug Hurd of Mechanical engineering machine shop at University of Cincinnati for their assistance during these in-vitro experiments. NR 30 TC 25 Z9 26 U1 0 U2 5 PU BIOMED CENTRAL LTD PI LONDON PA 236 GRAYS INN RD, FLOOR 6, LONDON WC1X 8HL, ENGLAND SN 1475-925X J9 BIOMED ENG ONLINE JI Biomed. Eng. Online PD AUG 27 PY 2008 VL 7 AR 24 DI 10.1186/1475-925X-7-24 PG 22 WC Engineering, Biomedical SC Engineering GA 355JS UT WOS:000259705800001 PM 18752683 ER PT J AU Lin, B Stackhouse, PW Minnis, P Wielicki, BA Hu, YX Sun, WB Fan, TF Hinkelman, LM AF Lin, Bing Stackhouse, Paul W., Jr. Minnis, Patrick Wielicki, Bruce A. Hu, Yongxiang Sun, Wenbo Fan, Tai-Fang Hinkelman, Laura M. TI Assessment of global annual atmospheric energy balance from satellite observations SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID LATENT-HEAT FLUXES; RADIATIVE FLUXES; CLOUDS; SYSTEM; PRECIPITATION; VALIDATION; TRANSPORTS; SURFACE; ISCCP; TOP AB Global atmospheric energy balance is one of the fundamental processes for the earth's climate system. This study uses currently available satellite data sets of radiative energy at the top of atmosphere (TOA) and surface as well as latent and sensible heat over the oceans for the year 2000 to assess the global annual energy budget. Over land, surface radiation data are used to constrain assimilated results and to force the radiation, turbulent heat, and heat storage into balance due to a lack of observation-based turbulent heat flux estimates. Global annual means of the TOA net radiation obtained from both satellite direct measurements and calculations are close to zero. The net radiative energy fluxes into the surface and the surface latent heat transported into the atmosphere are about 113 and 86 W/m(2), respectively. The estimated atmospheric and surface heat imbalances are about -8 and 9 W/m(2), respectively, values that are within the uncertainties of surface radiation and sea surface turbulent flux estimates and the likely systematic biases in the analyzed observations. The potential significant additional absorption of solar radiation within the atmosphere suggested by previous studies does not appear to be required to balance the energy budget: the spurious heat imbalances in the current data are much smaller (about half) than those obtained previously and debated about a decade ago. Progress in surface radiation and oceanic turbulent heat flux estimations from satellite measurements has significantly reduced the bias errors in the observed global energy budgets of the climate system. C1 [Lin, Bing; Stackhouse, Paul W., Jr.; Minnis, Patrick; Wielicki, Bruce A.; Hu, Yongxiang] NASA, Langley Res Ctr, Sci Directorate, Hampton, VA 23681 USA. [Fan, Tai-Fang] SSAI, Hampton, VA 23666 USA. [Hinkelman, Laura M.] Univ Washington, Joint Inst Study Atmosphere & Oceans, Seattle, WA 98195 USA. [Sun, Wenbo] Hampton Univ, Ctr Atmospher Sci, Hampton, VA 23668 USA. RP Lin, B (reprint author), NASA, Langley Res Ctr, Sci Directorate, Hampton, VA 23681 USA. EM bing.lin@nasa.gov RI Hinkelman, Laura/L-8964-2016; Minnis, Patrick/G-1902-2010; Hu, Yongxiang/K-4426-2012 OI Hinkelman, Laura/0000-0001-6477-9648; Minnis, Patrick/0000-0002-4733-6148; FU NASA Energy FX The authors would like to express their appreciation to M. Rodell, G. Huffman, G. Gibson, C. A. Schlosser, R. Arduini, P. Houser, D. Young, D. Garber, and T. Wong for their valuable comments and encouragement. This research was supported by the NASA Energy and Water cycle Studies (NEWS) program and CERES mission. CERES and SRB products and sea surface data were obtained from the NASA Langley Atmospheric Sciences Data Center in Hampton, Virginia, and the Goddard Distributed Active Archive Center in Greenbelt, Maryland, respectively. ISCCP data are available from NASA Goddard Institute for Space Studies, New York, New York. The GPCP data are archived at the World Meteorological Organization's World Data Center located at the National Climatic Data Center, Asheville, North Carolina. A backup FTP site for the Version 2 and 1DD products is located at the NASA Goddard Space Flight Center, Greenbelt, Maryland. NR 28 TC 21 Z9 22 U1 0 U2 6 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 AUG 27 PY 2008 VL 113 IS D16 AR D16114 DI 10.1029/2008JD009869 PG 7 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 342ZI UT WOS:000258821700007 ER PT J AU Rothschild, LJ AF Rothschild, Lynn J. TI The evolution of photosynthesis ... again? SO PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES LA English DT Article DE photosynthesis; carbon fixation; carboxylase; evolution; rubisco; enzyme evolution ID AUTOTROPHIC CO2 FIXATION; TRICARBOXYLIC-ACID CYCLE; OXYGENIC PHOTOSYNTHESIS; CARBON FIXATION; CONVERGENT EVOLUTION; 3-HYDROXYPROPIONATE CYCLE; CHLOROFLEXUS-AURANTIACUS; CHLOROBIUM-TEPIDUM; SULFUR METABOLISM; GREAT OXIDATION AB Replaying the tape' is an intriguing 'would it happen again?' exercise. With respect to broad evolutionary innovations, such as photosynthesis, the answers are central to our search for life elsewhere. Photosynthesis permits a large planetary biomass on Earth. Specifically, oxygenic photosynthesis has allowed an oxygenated atmosphere and the evolution of large metabolically demanding creatures, including ourselves. There are at least six prerequisites for the evolution of biological carbon fixation: a carbon-based life form; the presence of inorganic carbon; the availability of reductants; the presence of light; a light-harvesting mechanism to convert the light energy into chemical energy; and carboxylating enzymes. All were present on the early Earth. To provide the evolutionary pressure, organic carbon must be a scarce resource in contrast to inorganic carbon. The probability of evolving a carboxylase is approached by creating an inventory of carbon-fixation enzymes and comparing them, leading to the conclusion that carbon fixation in general is basic to life and has arisen multiple times. Certainly, the evolutionary pressure to evolve new pathways for carbon fixation would have been present early in evolution. From knowledge about planetary systems and extraterrestrial chemistry, if organic carbon-based life occurs elsewhere, photosynthesis-although perhaps not oxygenic photosynthesis-would also have evolved. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Rothschild, LJ (reprint author), NASA, Ames Res Ctr, Mail Stop 239-20, Moffett Field, CA 94035 USA. EM lynn.j.rothschild@nasa.gov NR 85 TC 18 Z9 20 U1 8 U2 27 PU ROYAL SOC PI LONDON PA 6-9 CARLTON HOUSE TERRACE, LONDON SW1Y 5AG, ENGLAND SN 0962-8436 J9 PHILOS T R SOC B JI Philos. Trans. R. Soc. B-Biol. Sci. PD AUG 27 PY 2008 VL 363 IS 1504 BP 2787 EP 2801 DI 10.1098/rstb.2008.0056 PG 15 WC Biology SC Life Sciences & Biomedicine - Other Topics GA 325EK UT WOS:000257571100015 PM 18487134 ER PT J AU Kobayashi, NP Williams, RS AF Kobayashi, Nobuhiko P. Williams, R. Stanley TI Two-Stage Atomic Layer Deposition of Aluminum Oxide on Alkanethiolate Self-Assembled Monolayers Using n-Propanol and Water as Oxygen Sources SO CHEMISTRY OF MATERIALS LA English DT Article ID INFRARED-SPECTROSCOPY; PATHWAYS; SURFACES; GROWTH; DYNAMICS; AL2O3; MODES; FILMS AB Aluminum oxide (AlOx) was deposited onto strong hydrophobic surfaces of alkanethiolate self-assembled monolayers (SAMs) by a two-stage atomic layer deposition (ALD) process; the first stage utilized n-propanol as the oxygen source, and the second stage proceeded with water. The resulting AlOx layers were characterized with spectroscopic ellipsometry, reflection-absorption infrared spectroscopy, low-energy X-ray emission spectroscopy, and atomic force microscopy. The optimized two-step ALD process significantly improved the surface morphology of AlOx layers and effectively protected the structural integrities of underlying SAMS. C1 [Kobayashi, Nobuhiko P.] Univ Calif Santa Cruz, Jack Baskin Sch Engn, Santa Cruz, CA 95064 USA. [Kobayashi, Nobuhiko P.; Williams, R. Stanley] Hewlett Packard Labs, Informat & Quantum Syst Lab, Palo Alto, CA 94304 USA. [Kobayashi, Nobuhiko P.] Univ Calif Santa Cruz, NECTAR, Adv Studies Labs, Santa Cruz, CA 95064 USA. [Kobayashi, Nobuhiko P.] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Kobayashi, NP (reprint author), Univ Calif Santa Cruz, Jack Baskin Sch Engn, Santa Cruz, CA 95064 USA. EM nobby@soe.ucsc.edu RI Williams, R. Stanley/A-8281-2009; Kobayashi, Nobuhiko/E-3834-2012 OI Williams, R. Stanley/0000-0003-0213-4259; NR 25 TC 7 Z9 7 U1 1 U2 10 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0897-4756 EI 1520-5002 J9 CHEM MATER JI Chem. Mat. PD AUG 26 PY 2008 VL 20 IS 16 BP 5356 EP 5360 DI 10.1021/cm702848y PG 5 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 339MA UT WOS:000258580500038 ER PT J AU Lyapustin, A Wang, Y Frey, R AF Lyapustin, A. Wang, Y. Frey, R. TI An automatic cloud mask algorithm based on time series of MODIS measurements SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article AB [1] Quality of aerosol retrievals and atmospheric correction over land depends strongly on accuracy of the cloud mask (CM) algorithm. The heritage CM algorithms developed for AVHRR and MODIS use the latest sensor measurements of spectral reflectance and brightness temperature and perform processing at the pixel level. The algorithms are threshold-based and empirically tuned. They do not explicitly address the classical problem of cloud search, wherein the baseline clear-skies scene is defined for comparison. Here we report on a new land CM algorithm, which explicitly builds and maintains a reference clear-skies image of the surface (refcm) using a time series of MODIS measurements. The new algorithm, developed as part of the multiangle implementation of atmospheric correction (MAIAC) algorithm for MODIS, relies on the fact that clear-skies images of the same surface area have a common textural pattern, defined by the surface topography, boundaries of rivers and lakes, distribution of soils and vegetation, etc. This pattern changes slowly given the daily rate of global Earth observations, whereas clouds introduce high-frequency random disturbances. Under clear skies, consecutive gridded images of the same surface area have a high covariance, whereas in presence of clouds covariance is usually low. This idea is central to initialization of refcm, which is used to derive cloud mask in combination with spectral and brightness temperature tests. The refcm is continuously updated with the latest clear-skies MODIS measurements, thus adapting to seasonal and rapid surface changes. The algorithm is enhanced by an internal dynamic land-water-snow classification coupled with a surface change mask. An initial comparison shows that the new algorithm offers the potential to perform better than the MODIS MOD35 cloud mask in situations where the land surface is changing rapidly and over Earth regions covered by snow and ice. C1 [Lyapustin, A.; Wang, Y.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Frey, R.] Univ Wisconsin, Cooperat Inst Meteorol Satellite Studies, Ctr Space Sci & Engn, Madison, WI 53706 USA. RP Lyapustin, A (reprint author), NASA, Goddard Space Flight Ctr, Mail Code 614-4,Bld 33, Greenbelt, MD 20771 USA. EM alexei.i.lyapustin@nasa.gov RI Lyapustin, Alexei/H-9924-2014 OI Lyapustin, Alexei/0000-0003-1105-5739 FU NASA EOS Science FX The work of Dr. Lyapustin and Dr. Wang was supported by the NASA EOS Science (Dr. D. Wickland) grant. The first author is grateful to Dr. P. Menzel for helpful discussion and suggestions on this paper. NR 10 TC 48 Z9 48 U1 1 U2 8 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 AUG 26 PY 2008 VL 113 IS D16 AR D16207 DI 10.1029/2007JD009641 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 342ZC UT WOS:000258821100002 ER PT J AU Shirasaki, Y Yoshida, A Kawai, N Tamagawa, T Sakamoto, T Suzuki, M Nakagawa, Y Kobayashi, A Sugita, S Takahashi, I Arimoto, M Shimokawabe, T Pazmino, NV Ishimura, T Sato, R Matsuoka, M Fenimore, EE Galassi, M Lamb, DQ Graziani, C Donaghy, TQ Atteia, JL Pelangeon, A Vanderspek, R Crew, GB Doty, JP Villasenor, J Prigozhin, G Butler, N Ricker, GR Hurley, K Woosley, SE Pizzichini, G AF Shirasaki, Yuji Yoshida, Atsumasa Kawai, Nobuyuki Tamagawa, Toru Sakamoto, Takanori Suzuki, Motoko Nakagawa, Yujin Kobayashi, Akina Sugita, Satoshi Takahashi, Ichiro Arimoto, Makoto Shimokawabe, Takashi Pazmino, Nicolas Vasquez Ishimura, Takuto Sato, Rie Matsuoka, Masaru Fenimore, Edward E. Galassi, Mark Lamb, Donald Q. Graziani, Carlo Donaghy, Timothy Q. Atteia, Jean-Luc Pelangeon, Alexandre Vanderspek, Roland Crew, Geoffrey B. Doty, John P. Villasenor, Joel Prigozhin, Gregory Butler, Nat Ricker, George R. Hurley, Kevin Woosley, Stanford E. Pizzichini, Graziella TI Multiple-Component Analysis of the Time-Resolved Spectra of GRB 041006: A Clue to the Nature of the Underlying Soft Component of GRBs SO PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN LA English DT Article DE gamma-rays: bursts; X-rays: bursts; X-rays: individual (GRB 041006) ID GAMMA-RAY-BURSTS; ENERGY CORRELATIONS; AFTERGLOW; PRECURSORS; MODEL; VARIABILITY; PERFORMANCE; GRB-041006; REDSHIFT; BRIGHT AB GRB 041006 was detected by HETE-2 on 2004 October 06. The light curves in four different energy bands display different features. At higher energy bands several peaks are seen in the light curve, while at lower energy bands a single broader bump dominates. It is expected that these different features are the result of a mixture of several components, each of which has different energetics and variability. We analyzed the time-resolved spectra, which were resolved into several components. These components can be classified into two distinct classes. One is a component that has an exponential decay of E-p with a characteristic timescale shorter than similar to 30 s; its spectrum is well represented by a broken power-law function, which is frequently observed in many prompt GRB emissions, so it should have an internal-shock origin. Another is a component whose E-p is almost unchanged with a characteristic timescale longer than similar to 60 s, and shows a very soft emission and slower variability. The spectrum is characterized by either a broken power law or a black-body spectrum. By assuming that the soft component is a thermal emission, the radiation radius is initially 4.4 x 10(6) km, which is a typical radius of a blue supergiant, and its expansion velocity is 2.4 x 10(5) km s(-1) in the source frame. C1 [Shirasaki, Yuji] Natl Astron Observ Japan, Tokyo 1818588, Japan. [Yoshida, Atsumasa; Nakagawa, Yujin; Kobayashi, Akina; Sugita, Satoshi; Takahashi, Ichiro] Aoyama Gakuin Univ, Dept Math & Phys, Kanagawa 2298558, Japan. [Kawai, Nobuyuki; Arimoto, Makoto; Shimokawabe, Takashi; Pazmino, Nicolas Vasquez; Ishimura, Takuto] Tokyo Inst Technol, Dept Phys, Meguro Ku, Tokyo 1528551, Japan. [Yoshida, Atsumasa; Kawai, Nobuyuki; Tamagawa, Toru; Sugita, Satoshi] RIKEN, Wako, Saitama 3510198, Japan. [Sakamoto, Takanori] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Suzuki, Motoko; Matsuoka, Masaru] JAXA, Tsukuba, Ibaraki 3058505, Japan. [Sato, Rie] JAXA ISAS, Sagamihara, Kanagawa 2298510, Japan. [Fenimore, Edward E.; Galassi, Mark] Los Alamos Natl Lab, Los Alamos, NM 87545 USA. [Lamb, Donald Q.; Graziani, Carlo; Donaghy, Timothy Q.] Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. [Atteia, Jean-Luc; Pelangeon, Alexandre] Univ Toulouse, CNRS, LATT, F-31400 Toulouse, France. [Vanderspek, Roland; Crew, Geoffrey B.; Doty, John P.; Villasenor, Joel; Prigozhin, Gregory; Butler, Nat; Ricker, George R.] MIT, Ctr Space Res, Cambridge, MA 02139 USA. [Butler, Nat; Hurley, Kevin] Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. [Woosley, Stanford E.] Univ Calif Santa Cruz, Dept Astron & Astrophys, Santa Cruz, CA 95064 USA. [Pizzichini, Graziella] INAF IASF Bologna, I-40129 Bologna, Italy. RP Shirasaki, Y (reprint author), Natl Astron Observ Japan, 2-21-1 Osawa, Tokyo 1818588, Japan. EM yuji.shirasaki@nao.ac.jp FU NASA [NASW-4690]; Ministry of Education, Culture, Sports, Science and Technology [14079102]; CNES [793-01-8479]; Ministry of Education, Culture, Sports, Science and Technology of Japan [15017289, 18049074, 17700085]; MIT [SC-A-293291] FX We would like to thank the HETE-2 team members for their support. The HETE-2 mission is supported in the US by NASA contract NASW-4690; in Japan in part by Grant-in-Aid 14079102 from the Ministry of Education, Culture, Sports, Science and Technology; and in France by CNES contract 793-01-8479. YS is grateful for support under the JSPS Core-to-Core Program, Grant-in-aid for Information Science (15017289 and 18049074) and Young Scientists (B) (17700085) carried out by the Ministry of Education, Culture, Sports, Science and Technology of Japan. KH is grateful for support under MIT Contract SC-A-293291, NR 39 TC 9 Z9 9 U1 0 U2 0 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0004-6264 EI 2053-051X J9 PUBL ASTRON SOC JPN JI Publ. Astron. Soc. Jpn. PD AUG 25 PY 2008 VL 60 IS 4 BP 919 EP 931 DI 10.1093/pasj/60.4.919 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 377BE UT WOS:000261225900025 ER PT J AU Motagh, M Walter, TR Sharifi, MA Fielding, E Schenk, A Anderssohn, J Zschau, J AF Motagh, Mahdi Walter, Thomas R. Sharifi, Mohammad Ali Fielding, Eric Schenk, Andreas Anderssohn, Jan Zschau, Jochen TI Land subsidence in Iran caused by widespread water reservoir overexploitation SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SYNTHETIC-APERTURE RADAR; LAS-VEGAS; ANTELOPE VALLEY; NORTHEAST IRAN; EARTHS SURFACE; INTERFEROMETRY; CALIFORNIA; INSAR; DEFORMATION; NEVADA AB The increasing demands upon groundwater resources due to expanding metropolitan and agricultural areas are a serious challenge, particularly in semiarid and arid regions. In Iran, decades of unrestrained groundwater extraction for domestic, agricultural, and industrial use have resulted in a precipitous depletion of this valuable resource. Here we show that the decline in groundwater levels is associated with land-surface deformation on local and regional scales. Combining water-level data with satellite radar observations provides evidence for the prevalence of compacting aquifers in the country. Groundwater level decline is often associated with destruction of the aquifers, which appears to be a common problem in the groundwater basins of central and northeast Iran. Global warming and future climate change will affect arid and semiarid areas in the coming decades, further augmenting hazards associated with groundwater-induced land subsidence. C1 [Motagh, Mahdi; Walter, Thomas R.; Zschau, Jochen] Geoforschungszentrum Potsdam, Dept Earthquake Risk & Early Warning, D-14473 Potsdam, Germany. [Anderssohn, Jan] Geoforschungszentrum Potsdam, Dept Remote Sensing, D-14473 Potsdam, Germany. [Fielding, Eric] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Schenk, Andreas] Univ Karlsruhe, Geodet Inst, D-76131 Karlsruhe, Germany. [Sharifi, Mohammad Ali] Univ Tehran, Dept Geomat & Surveying Engn, Tehran, Iran. RP Motagh, M (reprint author), Geoforschungszentrum Potsdam, Dept Earthquake Risk & Early Warning, Telegrafenberg Haus E,Sekt 2-1, D-14473 Potsdam, Germany. EM motagh@gfz-potsdam.de; twalter@gfz-potsdam.de; sharifi@ut.ac.ir; eric.j.fielding@jpl.nasa.gov; schenk@gik.uni-karlsruhe.de; calypso@gfz-potsdam.de; zschau@gfz-potsdam.de RI Walter, Thomas/K-4857-2015; Fielding, Eric/A-1288-2007 OI Fielding, Eric/0000-0002-6648-8067 FU German Research Foundation [MO 1851/1-1] FX We thank Water Resources Management of Iran for providing piezometric data. M. M. gratefully acknowledges financial support from the German Research Foundation ( MO 1851/1-1). Contribution of the National Cartographic Center of Iran (NCC) through the research project 10426 is also acknowledged. Part of the research described in this paper was carried out at the Jet Propulsion Laboratory (JPL), California Institute of Technology, under a contract with NASA. Envisat data were provided by the European Space Agency via category-1 proposals 2892 and 3740. We thank Kevin Fleming and Alan Levander for their comments on the earlier version of this manuscript. We also thank Roland Burgmann, Pietro Teatini, and an anonymous reviewer for their thoughtful review of this paper and appreciate constructive comments by the Associate Editor. NR 22 TC 37 Z9 37 U1 0 U2 18 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 AUG 23 PY 2008 VL 35 IS 16 AR L16403 DI 10.1029/2008GL033814 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 340KZ UT WOS:000258645800001 ER PT J AU Lyatsky, W Khazanov, GV AF Lyatsky, Wladislaw Khazanov, George V. TI Effect of geomagnetic disturbances and solar wind density on relativistic electrons at geostationary orbit SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID RADIATION BELT; ACCELERATION; STORMS; MAGNETOSPHERE; CHORUS AB It is well known that fluxes of relativistic electrons in the Earth's magnetosphere well correlate with solar wind speed but surprisingly they show a weaker correlation with geomagnetic activity indices. For a long time, this result seemed puzzling since geomagnetic disturbances, measured by geomagnetic activity indices, are associated with strong electric fields and low-frequency waves, which should significantly affect (directly or indirectly) the particle acceleration to high energies. To understand why the relativistic electron fluxes show the relatively weak correlation with geomagnetic disturbances, we investigated statistically the data of relativistic electrons at geostationary orbit for 6 years (1997 - 2002) and compared these data with solar wind parameters and geomagnetic activity indices. We found that, for the generation of the strong electron fluxes, the combination of two factors is needed: (1) strong geomagnetic disturbances about two days before the following increases in electron fluxes and (2) low solar wind density within these 2-day intervals between the geomagnetic disturbances and following increases in the electron fluxes. By these conditions, the correlation between the electron fluxes and geomagnetic indices is improved and becomes higher than the correlation between the electron fluxes and solar wind speed. A large majority of the strongest relativistic electron events occurred just during these conditions. This allows us to suggest that not solar wind speed alone but rather geomagnetic activity combined with low solar wind density conditions may be a primary cause for the generation of relativistic electrons. C1 [Lyatsky, Wladislaw; Khazanov, George V.] NASA, Marshall Space Flight Ctr, Space Plasma Grp, Huntsville, AL 35805 USA. RP Lyatsky, W (reprint author), NASA, Marshall Space Flight Ctr, Space Plasma Grp, 320 Sparkman Dr, Huntsville, AL 35805 USA. EM lyatsky@cspar.uah.edu FU NASA HQ POLAR Project; NASA LWS Program; Oak Ridge Associated Universities, Oak Ridge, Tennessee FX We gratefully acknowledge efforts of the NOAA staff in providing data on relativistic electron fluxes from the geostationary spacecraft, and the Goddard Space Flight Center and World Data Center for Geomagnetism in Kyoto, Japan, in providing solar wind data and geomagnetic activity indices. We are grateful to Robert Sheldon for useful discussions. 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 by NASA HQ POLAR Project and NASA LWS Program. Wladislaw Lyatsky is a fellow of Oak Ridge Associated Universities, Oak Ridge, Tennessee. NR 18 TC 15 Z9 15 U1 0 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 AUG 23 PY 2008 VL 113 IS A8 AR A08224 DI 10.1029/2008JA013048 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 340MW UT WOS:000258650700002 ER PT J AU Zhang, YY Klein, SA Liu, CT Tian, BJ Marchand, RT Haynes, JM Mccoy, RB Zhang, YY Ackerman, TP AF Zhang, Yunyan Klein, Stephen A. Liu, Chuntao Tian, Baijun Marchand, Roger T. Haynes, John M. Mccoy, Renata B. Zhang, Yuying Ackerman, Thomas P. TI On the diurnal cycle of deep convection, high-level cloud, and upper troposphere water vapor in the Multiscale Modeling Framework SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID GENERAL-CIRCULATION MODEL; CUMULUS CONVECTION; RESOLVING MODEL; RADAR OBSERVATIONS; TOGA COARE; PRECIPITATION; SATELLITE; PARAMETERIZATION; TRMM; SENSITIVITIES AB [1] The Multiscale Modeling Framework (MMF), also called "superparameterization'', embeds a cloud-resolving model (CRM) at each grid column of a general circulation model to replace traditional parameterizations of moist convection and large-scale condensation. This study evaluates the diurnal cycle of deep convection, high-level clouds, and upper troposphere water vapor by applying an infrared (IR) brightness temperature (T-b) and a precipitation radar (PR) simulator to the CRM column data. Simulator results are then compared with IR radiances from geostationary satellites and PR reflectivities from the Tropical Rainfall Measuring Mission (TRMM). While the actual surface precipitation rate in the MMF has a reasonable diurnal phase and amplitude when compared with TRMM observations, the IR simulator results indicate an inconsistency in the diurnal anomalies of high-level clouds between the model and the geostationary satellite data. Primarily because of its excessive high-level clouds, the MMF overestimates the simulated precipitation index (PI) and fails to reproduce the observed diurnal cycle phase relationships among PI, high-level clouds, and upper troposphere relative humidity. The PR simulator results show that over the tropical oceans, the occurrence fraction of reflectivity in excess of 20 dBZ is almost 1 order of magnitude larger than the TRMM data especially at altitudes above 6 km. Both results suggest that the MMF oceanic convection is overactive and possible reasons for this bias are discussed. However, the joint distribution of simulated IR Tb and PR reflectivity indicates that the most intense deep convection is found more often over tropical land than ocean, in agreement with previous observational studies. C1 [Zhang, Yunyan; Klein, Stephen A.; Mccoy, Renata B.; Zhang, Yuying] Lawrence Livermore Natl Lab, Atmospher Earth & Energy Div, PCMDI, Livermore, CA 94551 USA. [Liu, Chuntao] Univ Utah, Dept Meteorol, Salt Lake City, UT 84112 USA. [Tian, Baijun] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Haynes, John M.] Colorado State Univ, Dept Atmospher Sci, Ft Collins, CO 80523 USA. [Tian, Baijun] Univ Calif Los Angeles, Joint Inst Reg Earth Syst Sci & Engn, Los Angeles, CA USA. [Marchand, Roger T.; Ackerman, Thomas P.] Univ Washington, Joint Inst Study Atmosphere & Oceans, Seattle, WA 98195 USA. RP Zhang, YY (reprint author), Lawrence Livermore Natl Lab, Atmospher Earth & Energy Div, PCMDI, Livermore, CA 94551 USA. EM zhang25@llnl.gov; klein21@llnl.gov; liu.c.t@utah.edu; baijun.tian@jpl.nasa.gov; rojmarch@u.washington.edu; haynes@atmos.colostate.edu; mccoy20@llnl.gov; zhang24@llnl.gov; tpa2@u.washington.edu RI Zhang, Yunyan/F-9783-2011; Tian, Baijun/A-1141-2007; Zhang, Yuying/H-5011-2012; Klein, Stephen/H-4337-2016 OI Tian, Baijun/0000-0001-9369-2373; Klein, Stephen/0000-0002-5476-858X FU U. S. Department of Energy by Lawrence Livermore National Laboratory [DE-AC52-07NA27344] FX The authors thank Anthony T. Hoang for assistance with data transfer and storage. The authors also express their appreciation to Jiundar Chern and Wei-Kuo Tao for valuable discussions on the MMF and to Qiang Fu and Xianglei Huang for comments on the ice absorption coefficient. This work was supported through the Department of Energy's Atmospheric Radiation Measurement which is directed from the Biological and Environmental Research program at the Office of Science. This work was performed under the auspices of the U. S. Department of Energy by Lawrence Livermore National Laboratory under contract DE-AC52-07NA27344. NR 59 TC 29 Z9 29 U1 2 U2 12 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 AUG 22 PY 2008 VL 113 IS D16 AR D16105 DI 10.1029/2008JD009905 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 340LH UT WOS:000258646600005 ER PT J AU Leblanc, F Witasse, O Lilensten, J Frahm, RA Safaenili, A Brain, DA Mouginot, J Nilsson, H Futaana, Y Halekas, J Holmstrom, M Bertaux, JL Winningham, JD Kofman, W Lundin, R AF Leblanc, F. Witasse, O. Lilensten, J. Frahm, R. A. Safaenili, Ali Brain, D. A. Mouginot, J. Nilsson, H. Futaana, Y. Halekas, J. Holmstrom, M. Bertaux, J. L. Winningham, J. D. Kofman, W. Lundin, R. TI Observations of aurorae by SPICAM ultraviolet spectrograph on board Mars Express: Simultaneous ASPERA-3 and MARSIS measurements SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID CRUSTAL MAGNETIC-FIELD; PLASMA; ATMOSPHERE AB We present a new set of observations of Martian aurorae obtained by Spectroscopy for the Investigation of the Characteristics of the Atmosphere of Mars (SPICAM) on board Mars Express (MEX). Using nadir viewing, several auroral events have been identified on the Martian nightside, all near regions of crustal magnetic fields. For most of these events, two to three consecutive events with variable intensities and separated by a few seconds to several tens of seconds have been observed, whereas simultaneous observations with Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS) and Analyzer of Space Plasma and Energetic Atoms (ASPERA-3) have been possible. In this paper, we present the data set for these events and discuss the possible correlation between the measured UV emission by SPICAM, the measured downward and/or upward flux of electrons by ASPERA-3 and the total electron content recorded by MARSIS. Despite the limited coverage of SPICAM ultraviolet spectrograph (UVS) on the Martian nightside (essentially in regions of high crustal magnetic fields), there is however a very good correlation between the regions with the locally smallest probability to be on closed crustal magnetic field lines, as derived from Mars Global Surveyor/Electron Reflectometer (MGS/MAG-ER), and the position of an aurora event. This suggests that the crustal magnetic fields, when organized into cusp-like structure, can trigger the few aurorae identified by SPICAM UVS. It confirms also the good probability, in the cases where SPICAM UVS measured UV emissions, that the increase in the measured total electron content by MARSIS and the simultaneous measured precipitating electron flux by the ASPERA-3/Electron Spectrometer may be related to each other. C1 [Leblanc, F.] Osserv Astron Trieste, I-34131 Trieste, Italy. [Bertaux, J. L.] CNRS, IPSL, Serv Aeron, F-91371 Verrieres Le Buisson, France. [Brain, D. A.; Halekas, J.] Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. [Frahm, R. A.; Winningham, J. D.] SW Res Inst, San Antonio, TX 78228 USA. [Nilsson, H.; Futaana, Y.; Holmstrom, M.; Lundin, R.] Swedish Inst Space Phys, S-98128 Kiruna, Sweden. [Lilensten, J.; Mouginot, J.; Kofman, W.] Lab Planetol Grenoble, F-38041 Grenoble 9, France. [Safaenili, Ali] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Witasse, O.] ESA, Estec, Res & Sci Support Dept, NL-2200 AG Noordwijk, Netherlands. RP Leblanc, F (reprint author), Osserv Astron Trieste, Via Tieppolo 11, I-34131 Trieste, Italy. EM francois.leblanc@aerov.jussieu.fr RI Kofman, Wlodek/C-4556-2008; Futaana, Yoshifumi/P-5899-2014; Mouginot, Jeremie/G-7045-2015; OI Futaana, Yoshifumi/0000-0002-7056-3517; Halekas, Jasper/0000-0001-5258-6128 NR 27 TC 37 Z9 38 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 AUG 22 PY 2008 VL 113 IS A8 AR A08311 DI 10.1029/2008JA013033 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 340MV UT WOS:000258650600004 ER PT J AU Scholes, RJ Mace, GM Turner, W Geller, GN Jurgens, N Larigauderie, A Muchoney, D Walther, BA Mooney, HA AF Scholes, R. J. Mace, G. M. Turner, W. Geller, G. N. Juergens, N. Larigauderie, A. Muchoney, D. Walther, B. A. Mooney, H. A. TI Ecology - Toward a global biodiversity observing system SO SCIENCE LA English DT Editorial Material ID INDICATORS C1 [Scholes, R. J.] CSIR, ZA-0001 Pretoria, South Africa. [Mace, G. M.] Univ London Imperial Coll Sci Technol & Med, Ctr Populat Biol, NERC, Ascot SL5 7PY, Berks, England. [Turner, W.] NASA Headquarters, Div Earth Sci, Washington, DC 20546 USA. [Geller, G. N.] CALTECH, Jet Prop Lab, NASA Ecol Forecasting Program, Pasadena, CA 91109 USA. [Juergens, N.] Univ Hamburg, Bioctr Klein Flottbek, D-22609 Hamburg, Germany. [Juergens, N.] Univ Hamburg, Bot Garden, D-22609 Hamburg, Germany. [Larigauderie, A.; Walther, B. A.] Museum Natl Hist Nat, DIVERSITAS, F-75231 Paris 05, France. [Muchoney, D.] GEO, CH-1211 Geneva 2, Switzerland. [Mooney, H. A.] Stanford Univ, Dept Biol Sci, Stanford, CA 94305 USA. RP Scholes, RJ (reprint author), CSIR, POB 395, ZA-0001 Pretoria, South Africa. EM bscholes@csir.co.za RI Mace, Georgina/I-3072-2016; OI Mace, Georgina/0000-0001-8965-5211; Geller, Gary/0000-0002-4490-6002; Scholes, Robert/0000-0001-5537-6935 NR 10 TC 114 Z9 125 U1 4 U2 37 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 AUG 22 PY 2008 VL 321 IS 5892 BP 1044 EP 1045 DI 10.1126/science.1162055 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 339RL UT WOS:000258594900022 PM 18719268 ER PT J AU Jackson, TL Farrell, WM Delory, GT Nithianandam, J AF Jackson, Telana L. Farrell, William M. Delory, Greg T. Nithianandam, Jeyasingh TI Effect of dust absorption on the electron avalanche process occurring within Martian dust storms SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID OXIDANT ENHANCEMENT; DEVILS; FIELD; MARS AB Martian dust devils and storms are believed to generate and maintain large-scale E-fields which may be strong enough to create a weakly ionized plasma in the low pressure CO(2) atmosphere. Previous studies of the electron development included a determination of the avalanching electron growth via electron impact ionization with CO(2) at electron energy levels above 14 eV. Townsend's first coefficient defining the path length for impact ionization was calculated as a function of driving electric field. Such calculations demonstrated the growth of the electron avalanche but did not include any electron loss processes. Herein, we consider the effect of such a loss process: electron absorption by dust grains. The inclusion of electron-dust absorption has a moderating effect, controlling electron avalanche growth. A critical E-field to initiate the avalanche is derivable, with fields below similar to 7 kV/m quenching the process but above 7 kV/m fully capable of stimulating electron growth in the storm. C1 [Jackson, Telana L.; Farrell, William M.] NASA, Goddard Space Flight Ctr, Solar Syst Explorat Div, Greenbelt, MD 20771 USA. [Delory, Greg T.; Nithianandam, Jeyasingh] Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Morgan State Univ, Dept Elect Engn, Baltimore, MD 21251 USA. RP Jackson, TL (reprint author), NASA, Goddard Space Flight Ctr, Solar Syst Explorat Div, Greenbelt, MD 20771 USA. EM telana.l.jackson@nasa.gov RI Jackson, Telana/E-9102-2012; Farrell, William/I-4865-2013 NR 18 TC 5 Z9 5 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 AUG 21 PY 2008 VL 35 IS 16 AR L16201 DI 10.1029/2008GL034523 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 340KW UT WOS:000258645500001 ER PT J AU Lefevre, F Bertaux, JL Clancy, RT Encrenaz, T Fast, K Forget, F Lebonnois, S Montmessin, F Perrier, S AF Lefevre, Franck Bertaux, Jean-Loup Clancy, R. Todd Encrenaz, Therese Fast, Kelly Forget, Francois Lebonnois, Sebastien Montmessin, Franck Perrier, Severine TI Heterogeneous chemistry in the atmosphere of Mars SO NATURE LA English DT Article ID MARTIAN ATMOSPHERE; WATER-VAPOR; INTERANNUAL VARIABILITY; OZONE; SPECTROSCOPY; STABILITY; APHELION; H2O2; PHOTOCHEMISTRY; ABUNDANCE AB Hydrogen radicals are produced in the martian atmosphere by the photolysis of water vapour and subsequently initiate catalytic cycles that recycle carbon dioxide from its photolysis product carbon monoxide(1,2). These processes provide a qualitative explanation for the stability of the atmosphere of Mars, which contains 95 per cent carbon dioxide. Balancing carbon dioxide production and loss based on our current understanding of the gas-phase chemistry in the martian atmosphere has, however, proven to be difficult(3-5). Interactions between gaseous chemical species and ice cloud particles have been shown to be key factors in the loss of polar ozone observed in the Earth's stratosphere(6), and may significantly perturb the chemistry of the Earth's upper troposphere(7). Water-ice clouds are also commonly observed in the atmosphere of Mars(8-10) and it has been suggested previously that heterogeneous chemistry could have an important impact on the composition of the martian atmosphere(3-5,11). Here we use a state-of-the- art general circulation model together with new observations of the martian ozone layer(12-15) to show that model simulations to much improved quantitative agreement with observed martian ozone levels in comparison with model simulations based on gas-phase chemistry alone. Ozone is readily destroyed by hydrogen radicals and is therefore a sensitive tracer of the chemistry that regulates the atmosphere of Mars. Our results suggest that heterogeneous chemistry on ice clouds plays an important role in controlling the stability and composition of the martian atmosphere. C1 [Lefevre, Franck] Univ Paris 06, UPMC, Serv Aeron, F-75005 Paris, France. [Lefevre, Franck; Bertaux, Jean-Loup; Encrenaz, Therese; Forget, Francois; Lebonnois, Sebastien; Montmessin, Franck; Perrier, Severine] CNRS, INSU, F-75700 Paris, France. [Bertaux, Jean-Loup; Montmessin, Franck; Perrier, Severine] Univ Versailles St Quentin, Serv Aeron, F-91371 Verrieres Le Buisson, France. [Clancy, R. Todd] Space Sci Inst, Boulder, CO 80301 USA. [Encrenaz, Therese] Observ Paris, LESIA, F-92195 Meudon, France. [Fast, Kelly] NASA, Goddard Space Flight Ctr, Planetary Syst Lab, Greenbelt, MD 20771 USA. [Forget, Francois; Lebonnois, Sebastien] Univ Paris 06, UPMC, Meteorol Dynam Lab, F-75005 Paris, France. RP Lefevre, F (reprint author), Univ Paris 06, UPMC, Serv Aeron, F-75005 Paris, France. EM franck.lefevre@aero.jussieu.fr OI LEBONNOIS, SEBASTIEN/0000-0002-2390-8164 NR 30 TC 47 Z9 48 U1 1 U2 11 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD AUG 21 PY 2008 VL 454 IS 7207 BP 971 EP 975 DI 10.1038/nature07116 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 339QB UT WOS:000258591000033 PM 18719584 ER PT J AU Padin, S Staniszewski, Z Keisler, R Joy, M Stark, AA Ade, PAR Aird, KA Benson, BA Bleem, LE Carlstrom, JE Chang, CL Crawford, TM Crites, AT Dobbs, MA Halverson, NW Heimsath, S Hills, RE Holzapfel, WL Lawrie, C Lee, AT Leitch, EM Leong, J Lu, W Lueker, M McMahon, JJ Meyer, SS Mohr, JJ Montroy, TE Plagge, T Pryke, C Ruhl, JE Schaffer, KK Shirokoff, E Spieler, HG Vieira, JD AF Padin, S. Staniszewski, Z. Keisler, R. Joy, M. Stark, A. A. Ade, P. A. R. Aird, K. A. Benson, B. A. Bleem, L. E. Carlstrom, J. E. Chang, C. L. Crawford, T. M. Crites, A. T. Dobbs, M. A. Halverson, N. W. Heimsath, S. Hills, R. E. Holzapfel, W. L. Lawrie, C. Lee, A. T. Leitch, E. M. Leong, J. Lu, W. Lueker, M. McMahon, J. J. Meyer, S. S. Mohr, J. J. Montroy, T. E. Plagge, T. Pryke, C. Ruhl, J. E. Schaffer, K. K. Shirokoff, E. Spieler, H. G. Vieira, J. D. TI South Pole Telescope optics SO APPLIED OPTICS LA English DT Article ID REFLECTOR; ANTENNAS AB The South Pole Telescope is a 10 m diameter, wide-field, offset Gregorian telescope with a 966-pixel, millimeter-wave, bolometer array receiver. The telescope has an unusual optical system with a cold stop around the secondary. The design emphasizes low scattering and low background loading. All the optical components except the primary are cold, and the entire beam from prime focus to the detectors is surrounded by cold absorber. (C) 2008 Optical Society of America. C1 [Padin, S.; Keisler, R.; Bleem, L. E.; Carlstrom, J. E.; Chang, C. L.; Crawford, T. M.; Crites, A. T.; Leitch, E. M.; McMahon, J. J.; Meyer, S. S.; Pryke, C.; Schaffer, K. K.; Vieira, J. D.] Univ Chicago, Kavli Inst Cosmol Phys, Chicago, IL 60637 USA. [Padin, S.; Carlstrom, J. E.; Crawford, T. M.; Crites, A. T.; Meyer, S. S.; Pryke, C.] Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. [Staniszewski, Z.; Lawrie, C.; Leong, J.; Lu, W.; Montroy, T. E.; Ruhl, J. E.] Case Western Reserve Univ, Dept Phys, Cleveland, OH 44106 USA. [Keisler, R.; Bleem, L. E.; Carlstrom, J. E.; Meyer, S. S.; Vieira, J. D.] Univ Chicago, Dept Phys, Chicago, IL 60637 USA. [Joy, M.] NASA, George C Marshall Space Flight Ctr, VP62, Dept Space Sci, Huntsville, AL 35812 USA. [Stark, A. A.] Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. [Ade, P. A. R.] Cardiff Univ, Dept Phys & Astron, Cardiff CF24 3YB, England. [Aird, K. A.] Univ Chicago, Chicago, IL 60637 USA. [Benson, B. A.; Holzapfel, W. L.; Lee, A. T.; Plagge, T.; Shirokoff, E.] Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. [Carlstrom, J. E.; Chang, C. L.; McMahon, J. J.; Meyer, S. S.; Pryke, C.; Schaffer, K. K.] Univ Chicago, Enrico Fermi Inst, Chicago, IL 60637 USA. [Dobbs, M. A.] McGill Univ, Dept Phys, Montreal, PQ H3A 2T8, Canada. [Halverson, N. W.] Univ Colorado, Ctr Astrophys & Space Astron, Dept Astrophys & Planetary Sci, Boulder, CO 80309 USA. [Halverson, N. W.] Univ Colorado, Dept Phys, Boulder, CO 80309 USA. [Hills, R. E.] Atacama Large Millimeter Array, Santiago, Chile. [Mohr, J. J.] Univ Illinois, Dept Astron, Urbana, IL 61801 USA. [Mohr, J. J.] Univ Illinois, Dept Phys, Urbana, IL 61801 USA. [Spieler, H. G.] Lawrence Berkeley Natl Lab, Div Phys, Berkeley, CA 94720 USA. RP Padin, S (reprint author), Univ Chicago, Kavli Inst Cosmol Phys, 5640 S Ellis Ave, Chicago, IL 60637 USA. EM spadin@uchicago.edu RI Holzapfel, William/I-4836-2015; OI Aird, Kenneth/0000-0003-1441-9518; Stark, Antony/0000-0002-2718-9996 FU National Science Foundation [OPP-0130612] FX This work was supported by the National Science Foundation under grant OPP-0130612. NR 16 TC 32 Z9 32 U1 1 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 AUG 20 PY 2008 VL 47 IS 24 BP 4418 EP 4428 DI 10.1364/AO.47.004418 PG 11 WC Optics SC Optics GA 347GI UT WOS:000259128200016 PM 18716649 ER PT J AU Krejny, M Chuss, D d'Aubigny, CD Golish, D Houde, M Hui, H Kulesa, C Loewenstein, RF Moseley, SH Novak, G Voellmer, G Walker, C Wollack, E AF Krejny, Megan Chuss, David d'Aubigny, Christian Drouet Golish, Dathon Houde, Martin Hui, Howard Kulesa, Craig Loewenstein, Robert F. Moseley, S. Harvey Novak, Giles Voellmer, George Walker, Chris Wollack, Ed TI The Hertz/VPM polarimeter: design and first light observations SO APPLIED OPTICS LA English DT Article ID FAR-INFRARED POLARIMETRY; ARRAY POLARIMETRY; SUBMILLIMETER; TELESCOPE AB We present first results of Hertz/VPM, the first submillimeter polarimeter employing the dual Variable-delay Polarization Modulator (dual-VPM). This device differs from previously used polarization modulators in that it operates in translation, rather than mechanical rotation. We discuss the basic theory behind this device and its potential advantages over the commonly used half-wave plate. The dual-VPM was tested both at the Submillimeter Telescope Observatory and in the laboratory. In each case we present a detailed description of the setup. We discovered that properties of the VPM wire grids (diameter and spacing) caused behavior that differs from theoretical predictions for ideal wire grid performance. By modifying the polarimeter settings to compensate for this behavior, we found that the dual-VPM system is robust, operating with high efficiency and low instrumental polarization. This device is well suited for air- and space-borne applications. (C) 2008 Optical Society of America. C1 [Krejny, Megan; Novak, Giles] Northwestern Univ, Dept Phys & Astron, Evanston, IL 60208 USA. [Chuss, David; Hui, Howard; Moseley, S. Harvey; Voellmer, George; Wollack, Ed] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [d'Aubigny, Christian Drouet; Golish, Dathon; Kulesa, Craig; Walker, Chris] Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. [Houde, Martin] Univ Western Ontario, Dept Phys & Astron, London, ON N6A 3K7, Canada. [Hui, Howard] Oregon State Univ, Dept Phys, Corvallis, OR 97331 USA. [Loewenstein, Robert F.] Univ Chicago, Yerkes Observ, Williams Bay, WI 53191 USA. RP Krejny, M (reprint author), Northwestern Univ, Dept Phys & Astron, 2131 Tech Dr, Evanston, IL 60208 USA. EM m-krejny@northwestern.edu RI Moseley, Harvey/D-5069-2012; Chuss, David/D-8281-2012; Wollack, Edward/D-4467-2012 OI Wollack, Edward/0000-0002-7567-4451 FU National Aeronautics and Space Administration [NNG056K286, NNX07AB85G, NNG05GG42G, NNX07AI27G]; Graduate Student Researchers Program [NNG05-GL31H]; Undergraduate Student Research Program FX We thank Dominic Benford for his support of this work. This material is based upon work supported by the National Aeronautics and Space Administration under grants NNG056K286, NNX07AB85G, NNG05GG42G and NNX07AI27G, issued through the Science Mission Directorate. M. Krejny was supported by Graduate Student Researchers Program grant NNG05-GL31H. H. Hui was supported by an Undergraduate Student Research Program grant at Goddard Space Flight Center. NR 20 TC 13 Z9 13 U1 0 U2 0 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 AUG 20 PY 2008 VL 47 IS 24 BP 4429 EP 4440 DI 10.1364/AO.47.004429 PG 12 WC Optics SC Optics GA 347GI UT WOS:000259128200017 PM 18716650 ER PT J AU Allen, GE Houck, JC Sturner, SJ AF Allen, G. E. Houck, J. C. Sturner, S. J. TI Evidence of a curved synchrotron spectrum in the supernova remnant SN 1006 SO ASTROPHYSICAL JOURNAL LA English DT Article DE acceleration of particles; cosmic rays; ISM : individual (SN 1006); radiation mechanisms : nonthermal; supernova remnants; X-rays : general ID DIFFUSIVE SHOCK ACCELERATION; COSMIC-RAY ACCELERATION; HIGH-ENERGY ELECTRONS; X-RAY; MAGNETIC-FIELD; MAXIMUM ENERGY; SN 1006; PARTICLE-ACCELERATION; HIGH-RESOLUTION; NONLINEAR AMPLIFICATION AB A joint spectral analysis of some Chandra ACIS X-ray data and Molonglo Observatory Synthesis Telescope radio data was performed for 13 small regions along the bright northeastern rim of the supernova remnant SN 1006. These data were fitted with a synchrotron radiation model. The nonthermal electron spectrum used to compute the photon emission spectra is the traditional exponentially cut off power law, with one notable difference: The power-law index is not a constant. It is a linear function of the logarithm of the momentum. This functional form enables us to show, for the first time, that the synchrotron spectrum of SN 1006 seems to flatten with increasing energy. The effective power-law index of the electron spectrum is 2.2 at 1 GeV (i.e., radio synchrotron-emitting momenta) and 2.0 at about 10 TeV (i.e., X-ray synchrotron-emitting momenta). This amount of change in the index is qualitatively consistent with theoretical models of the amount of curvature in the proton spectrum of the remnant. The evidence of spectral curvature implies that cosmic rays are dynamically important instead of being "test'' particles. The spectral analysis also provides a means of determining the critical frequency of the synchrotron spectrum associated with the highest-energy electrons. The critical frequency seems to vary along the northeastern rim, with a maximum value of 1.1(-0.5)(+1.0) x 10(17) Hz. This value implies that the electron diffusion coefficient can be no larger than a factor of similar to 4.5-21 times the Bohm diffusion coefficient if the velocity of the forward shock is in the range 2300-5000 km s(-1). Since the coefficient is close to the Bohm limit, electrons are accelerated nearly as fast as possible in the regions where the critical frequency is about 10(17) Hz. C1 [Allen, G. E.; Houck, J. C.] MIT, Kavli Inst Astrophys & Space Res, Cambridge, MA 02139 USA. [Sturner, S. J.] NASA, Goddard Space Flight Ctr, Astroparticle Phys Lab, Greenbelt, MD 20771 USA. RP Allen, GE (reprint author), MIT, Kavli Inst Astrophys & Space Res, Cambridge, MA 02139 USA. EM gea@space.mit.edu; houck@space.mit.edu; sturner@swati.gsfc.nasa.gov OI Houck, John/0000-0002-6761-6796 NR 68 TC 31 Z9 31 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 AUG 20 PY 2008 VL 683 IS 2 BP 773 EP 785 DI 10.1086/589628 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 338SD UT WOS:000258528100014 ER PT J AU Gautier, TN Rebull, LM Stapelfeldt, KR Mainzer, A AF Gautier, Thomas. N., III Rebull, L. M. Stapelfeldt, K. R. Mainzer, A. TI Spitzer-MIPS observations of the eta Chamaeleontis young association SO ASTROPHYSICAL JOURNAL LA English DT Article DE circumstellar matter; infrared : stars; open clusters and associations : individual (eta Chamaeleontis); planetary systems; stars : pre-main-sequence ID MULTIBAND IMAGING PHOTOMETER; T-TAURI STARS; DISK EVOLUTION; ABSOLUTE CALIBRATION; C2D SURVEY; CLUSTER; CONSTRAINTS; BINARIES; DWARFS; CENSUS AB We have mapped the eta Chamaeleontis young stellar association in the far-infrared with the Multiband Imaging Photometer for Spitzer (MIPS) on the Spitzer Space Telescope. All 16 members within the map region were detected at 24 mu m, along with five members at 70 mu m and two at 160 mu m. Ten stars show far-infrared excess emission indicating the presence of circumstellar disks; six of these have central clearings as evidenced by the onset of excess emission at lambda > 5 mu m. No new infrared-excess sources are identified among the 113 2MASS field stars with 24 mu m photometry but not seen as X-ray sources, indicating that membership lists derived from X-ray surveys are reasonably complete. Circumstellar disks in the eta Cha association span the range from 10(-1) to 10(-4) in their fractional infrared luminosity, with a median L(d)/L(*) of 0.04. The presence of optically thick, optically thin, and intermediate optical depth disks within the same stellar group, in combination with the large fraction of disks with inner holes, indicates that the eta Cha association represents a crucial stage in circumstellar disk evolution. C1 [Gautier, Thomas. N., III; Stapelfeldt, K. R.; Mainzer, A.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Rebull, L. M.] Spitzer Sci Ctr, Pasadena, CA 91125 USA. RP Gautier, TN (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM tngautier@jpl.nasa.gov RI Stapelfeldt, Karl/D-2721-2012 FU NASA; NASA [1255094]; Jet Propulsion Laboratory; University of Massachusetts; National Aeronautics and Space Administration; National Science Foundation 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 contract with NASA. Support for this work was provided by NASA through contract 1255094. Gautier was also partially supported under the Research and Technical Development funds at the Jet Propulsion Laboratory. This work also 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 31 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 J9 ASTROPHYS J JI Astrophys. J. PD AUG 20 PY 2008 VL 683 IS 2 BP 813 EP 821 DI 10.1086/589708 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 338SD UT WOS:000258528100017 ER PT J AU Morgan, AN Berk, DEV Roming, PWA Nousek, JA Koch, TS Breeveld, AA de Pasquale, M Holland, ST Kuin, NPM Page, MJ Still, M AF Morgan, A. N. Berk, D. E. Vanden Roming, P. W. A. Nousek, J. A. Koch, T. S. Breeveld, A. A. de Pasquale, M. Holland, S. T. Kuin, N. P. M. Page, M. J. Still, M. TI Optimal co-addition of imaging data for rapidly fading gamma-ray burst afterglows SO ASTROPHYSICAL JOURNAL LA English DT Article DE gamma rays : bursts; methods : data analysis ID OPTIMAL EXTRACTION ALGORITHM; EARLY OPTICAL AFTERGLOWS; LIGHT CURVES; SWIFT; TELESCOPE; PHOTOMETRY; CALIBRATION; MISSION; UVOT; JET AB We present a technique for optimal co-addition of image data for rapidly varying sources, with specific application to gamma-ray burst (GRB) afterglows. Unweighted co-addition of rapidly fading afterglow light curve data becomes counterproductive relatively quickly. It is better to stop co-addition of the data once noise dominates late exposures. A better alternative is to optimally weight each exposure to maximize the signal-to-noise ratio (S/N) of the final co-added image data. By using information about GRB light curves and image noise characteristics, optimal image co-addition increases the probability of afterglow detection and places the most stringent upper limits on nondetections. For a temporal power-law flux decay typical of GRB afterglows, optimal co-addition has the greatest potential to improve the S/N of afterglow imaging data (relative to unweighted co-addition) when the decay rate is high, the source count rate is low, and the background rate is high. The optimal co-addition technique is demonstrated with applications to Swift Ultraviolet/Optical Telescope (UVOT) data of several GRBs, with and without detected afterglows. C1 [Morgan, A. N.; Berk, D. E. Vanden; Roming, P. W. A.; Nousek, J. A.; Koch, T. S.] Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA. [Morgan, A. N.] Univ Cambridge, Inst Astron, Cambridge CB3 0HA, England. [Breeveld, A. A.; de Pasquale, M.; Kuin, N. P. M.; Page, M. J.; Still, M.] Mullard Space Sci Lab, Surrey, England. [Holland, S. T.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Morgan, AN (reprint author), Penn State Univ, Dept Astron & Astrophys, 525 Davey Lab, University Pk, PA 16802 USA. FU NASA [NAS5-00136] FX Funding for the Swift program at Penn State is provided by NASA under the contract NAS5-00136. We acknowledge the use of public data from the Swift data archive. NR 41 TC 3 Z9 3 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 AUG 20 PY 2008 VL 683 IS 2 BP 913 EP 923 DI 10.1086/589639 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 338SD UT WOS:000258528100024 ER PT J AU Fortney, JJ Marley, MS Saumon, D Lodders, K AF Fortney, J. J. Marley, M. S. Saumon, D. Lodders, K. TI Synthetic spectra and colors of young giant planet atmospheres: Effects of initial conditions and atmospheric metallicity SO ASTROPHYSICAL JOURNAL LA English DT Review DE planetary systems; planets and satellites : formation; radiative transfer ID DWARF GLIESE 229B; LOW-MASS STARS; BROWN DWARFS; T-DWARFS; CHEMICAL-EQUILIBRIUM; EXTRASOLAR PLANETS; CARBON-MONOXIDE; EVOLUTIONARY MODELS; THERMAL STRUCTURE; GRAIN OPACITY AB We examine the spectra and infrared colors of the cool, methane-dominated atmospheres at T-eff <= 1400 K expected for young gas giant planets. We couple these spectral calculations to an updated version of the Marley et al. giant planet thermal evolution models that include formation by core accretion-gas capture. These relatively cool "young Jupiters'' can be 1-6 mag fainter than predicted by standard cooling tracks that include a traditional initial condition, which may provide a diagnostic of formation. If correct, this would make true Jupiter-like planets much more difficult to detect at young ages than previously thought. Since Jupiter and Saturn are of distinctly supersolar composition, we examine emitted spectra for model planets at both solar metallicity and a metallicity of 5 times solar. These metal-enhanced young Jupiters have lower pressure photospheres than field brown dwarfs of the same effective temperatures arising from both lower surface gravities and enhanced atmospheric opacity. We highlight several diagnostics for enhanced metallicity. A strongerCOabsorption band at 4.5 mu m for the warmest objects is predicted. At all temperatures, enhanced flux in K band is expected due to reduced collisional induced absorption by H-2. This leads to correspondingly redder near-infrared colors, which are redder than solar metallicity models with the same surface gravity by up to 0.7 in J-K and 1.5 in H-K. Molecular absorption band depths increase as well, most significantly for the coolest objects. We also qualitatively assess the changes to emitted spectra due to nonequilibrium chemistry. C1 [Fortney, J. J.] Univ Calif Santa Cruz, Dept Astron & Astrophys, UCO Lick Observ, Santa Cruz, CA 95064 USA. [Marley, M. S.] NASA, Ames Res Ctr, Space Sci & Astrobiol Div, Moffett Field, CA 94035 USA. [Saumon, D.] Los Alamos Natl Lab, Los Alamos, NM 87545 USA. [Lodders, K.] Washington Univ, Dept Earth & Planetary Sci, Planetary Chem Lab, St Louis, MO 63130 USA. RP Fortney, JJ (reprint author), Univ Calif Santa Cruz, Dept Astron & Astrophys, UCO Lick Observ, Santa Cruz, CA 95064 USA. EM jfortney@ucolick.org RI Marley, Mark/I-4704-2013; OI Fortney, Jonathan/0000-0002-9843-4354 FU Spitzer; NASA; NSF [AST 06-07489, AST 07-07377]; NASA Planetary Atmospheres Program; Spitzer Space Telescope; NASA [NNG06GC26G] FX We thank Bruce Macintosh and James Graham for numerous useful comments and suggestions, as well as for their enthusiasm for the project. J. J. F. acknowledges the support of a Spitzer Fellowship from NASA and NSF grant AST 06-07489. M. S. M. acknowledges the support of the NASA Planetary Atmospheres Program. D. S. acknowledges support from NASA through a Spitzer Space Telescope grant through a contract issued by JPL/Caltech. Work by K. L. is supported by NSF grant AST 07-07377 and NASA grant NNG06GC26G. NR 105 TC 144 Z9 144 U1 1 U2 7 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 AUG 20 PY 2008 VL 683 IS 2 BP 1104 EP 1116 DI 10.1086/589942 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 338SD UT WOS:000258528100039 ER PT J AU Lynch, BJ Antiochos, SK DeVore, CR Luhmann, JG Zurbuchen, TH AF Lynch, B. J. Antiochos, S. K. DeVore, C. R. Luhmann, J. G. Zurbuchen, T. H. TI Topological evolution of a fast magnetic breakout CME in three dimensions SO ASTROPHYSICAL JOURNAL LA English DT Article DE MHD; Sun : corona; Sun : coronal mass ejections (CMEs); Sun : magnetic fields ID CORONAL MASS EJECTION; SOLAR ERUPTIONS; FIELD TOPOLOGY; RECONNECTION; FLARE; MODEL; ACCELERATION; FILAMENT; EVENTS; SIGNATURES AB We present the extension of the magnetic breakout model for CME initiation to a fully three-dimensional, spherical geometry. Given the increased complexity of the dynamic magnetic field interactions in three dimensions, we first present a summary of the well known axisymmetric breakout scenario in terms of the topological evolution associated with the various phases of the eruptive process. In this context, we discuss the analogous topological evolution during the magnetic breakout CME initiation process in the simplest three-dimensional multipolar system. We show that an extended bipolar active region embedded in an oppositely directed background dipole field has all the necessary topological features required for magnetic breakout, i.e., a fan separatrix surface between the two distinct flux systems, a pair of spine field lines, and a true three-dimensional coronal null point at their intersection. We then present the results of a numerical MHD simulation of this three-dimensional system where boundary shearing flows introduce free magnetic energy, eventually leading to a fast magnetic breakout CME. The eruptive flare reconnection facilitates the rapid conversion of this stored free magnetic energy into kinetic energy and the associated acceleration causes the erupting field and plasma structure to reach an asymptotic eruption velocity of greater than or similar to 1100 km s(-1) over an similar to 15 minute time period. The simulation results are discussed using the topological insight developed to interpret the various phases of the eruption and the complex, dynamic, and interacting magnetic field structures. C1 [Lynch, B. J.; Luhmann, J. G.] Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. [Antiochos, S. K.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [DeVore, C. R.] USN, Res Lab, Computat Phys & Fluid Dynam Lab, Washington, DC 20375 USA. [Zurbuchen, T. H.] Univ Michigan, Dept Atmospher Ocean & Space Sci, Ann Arbor, MI 48109 USA. RP Lynch, BJ (reprint author), Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. RI Antiochos, Spiro/D-4668-2012; Lynch, Benjamin/B-1300-2013; DeVore, C/A-6067-2015; OI Antiochos, Spiro/0000-0003-0176-4312; DeVore, C/0000-0002-4668-591X; Lynch, Benjamin/0000-0001-6886-855X FU NSF SHINE [ATM-0621725]; NASA; Office of Naval Research (ONR); NASA HTP; TRT; SRT FX B. J. L. gratefully acknowledges current support from the NSF SHINE program ATM-0621725 and additional funding from NASA, the Office of Naval Research (ONR), and SSL/UCB participation in the Center for Integrated Space-weather Mg Modernization Program provided resources at the ERDC major shared resouodeling (CISM) collaboration. The DoD High Performance Computinrce and NRL-DC distributed computing centers for this research. This work was supported, in part, by the NASA HTP, TR&T, and SR&T programs. NR 61 TC 111 Z9 112 U1 1 U2 9 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 AUG 20 PY 2008 VL 683 IS 2 BP 1192 EP 1206 DI 10.1086/589738 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 338SD UT WOS:000258528100047 ER PT J AU Gezari, S Dessart, L Basa, S Martin, DC Neill, JD Woosley, SE Hillier, DJ Bazin, G Forster, K Friedman, PG Le Du, J Mazure, A Morrissey, P Neff, SG Schiminovich, D Wyder, TK AF Gezari, Suvi Dessart, Luc Basa, Stephane Martin, D. Chris Neill, James D. Woosley, S. E. Hillier, D. John Bazin, Gurvan Forster, Karl Friedman, Peter G. Le Du, Jeremy Mazure, Alain Morrissey, Patrick Neff, Susan G. Schiminovich, David Wyder, Ted K. TI Probing shock breakout with serendipitous GALEX detections of two SNLS type II-P supernovae SO ASTROPHYSICAL JOURNAL LETTERS LA English DT Article DE radiative transfer; stars : atmospheres; supernovae : general; ultraviolet : ISM ID QUANTITATIVE SPECTROSCOPIC ANALYSIS; MASSIVE STARS; X-RAY; UBVRI PHOTOMETRY; EVOLUTION; 2006BP; GRB-060218; EMISSION; SN-1987A; DISTANCE AB We report the serendipitous detection by GALEX of fast (< 1 day) rising ( >= 1 mag) UV emission from two Type II plateau ( II- P) supernovae ( SNe) at z = 0.185 and 0.324 discovered by the Supernova Legacy Survey. Optical photometry and VLT spectroscopy 2 weeks after the GALEX detections link the onset of UV emission to the time of shock breakout. Using radiation hydrodynamics and non-LTE radiative transfer simulations, and starting from a standard red supergiant (RSG; Type II-P SN progenitor) star evolved self-consistently from the main sequence to iron core collapse, we model the shock breakout phase and the 55 hr that follow. The small scale height of our RSG atmosphere model suggests that the breakout signature is a thermal soft X-ray burst (lambda(peak) similar to 90 angstrom) with a duration of <= 2000 s. Longer durations are possible but require either an extended and tenuous nonstandard envelope or an unusually dense RSG wind with (M) over dot similar to 10(-3) M(circle dot) yr(-1). The GALEX observations miss the peak of the luminous (M(FUV) approximate to -20) UV burst but unambiguously capture the rise of the emission and a subsequent 2 day long plateau. The postbreakout, UV-bright plateau is a prediction of our model in which the shift of the peak of the spectral energy distribution (SED) from similar to 100 to similar to 1000 angstrom and the ejecta expansion both counteract the decrease in bolometric luminosity from similar to 10(11) to similar to 10(9) L(circle dot) over that period. Based on the observed detection efficiency of our study, we ake predictions for the breakout detection rate of the GALEX Time Domain Survey. C1 [Gezari, Suvi] Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. [Dessart, Luc] Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. [Dessart, Luc] Princeton Univ, Dept Astrophys Sci, Princeton, NJ 08544 USA. [Basa, Stephane; Mazure, Alain] Astrophys Lab, F-13376 Marseille 12, France. [Martin, D. Chris; Neill, James D.; Forster, Karl; Friedman, Peter G.; Morrissey, Patrick; Wyder, Ted K.] CALTECH, Pasadena, CA 91125 USA. [Woosley, S. E.] Univ Calif Santa Cruz, Dept Astron & Astrophys, Santa Cruz, CA 95064 USA. [Hillier, D. John] Univ Pittsburgh, Dept Phys & Astron, Pittsburgh, PA 15260 USA. [Bazin, Gurvan] CEA Saclay, DSM DAPNIA, F-91191 Gif Sur Yvette, France. [Le Du, Jeremy] CNRS IN2P3, CPPM, F-13288 Marseille 9, France. [Le Du, Jeremy] Univ Aix Marseille 2, Case 907, F-13288 Marseille 9, France. [Neff, Susan G.] NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. [Schiminovich, David] Columbia Univ, Dept Astron, New York, NY 10027 USA. RP Gezari, S (reprint author), Johns Hopkins Univ, Dept Phys & Astron, 3400 N Charles St, Baltimore, MD 21218 USA. EM suvi@pha.jhu.edu FU DOE [DE-FC02-01ER41184, DE-FC02-06ER41452]; NSF [AST-0504947]; SciDAC [DE-FC02-06ER41438]; NASA [NNG05GG28G]; GALEX; CNES of France; Korean MOST.; ESO telescopes at the La Silla or Paranal Observatories [IDs 171.A-0486, 176.A-0589] FX We thank the anonymous referee for their helpful comments. L. D. acknowledges support for this work from the SciDAC program of the DOE, under grants DE-FC02-01ER41184 and DE-FC02-06ER41452, and from the NSF under grant AST-0504947. S. W. acknowledges support from the SciDAC under grant DE-FC02-06ER41438 and also by NASA under grant NNG05GG28G. S. G. and S. B. thank Bruno Milliard for his support during this study. We gratefully acknowledge NASA's support for construction, operation, and science analysis for the GALEX mission, developed in cooperation with CNES of France and the Korean MOST. Based on observations obtained with MegaPrime/MegaCam, a joint project of CFHT and CEA/DAPNIA, at the CFHT, which is operated by the NRC of Canada, the INSU of the CNRS of France, and the University of Hawaii. This work is based in part on data products produced at TERAPIX and the CADC as part of the CFHT Legacy Survey, a collaborative project of NRC and CNRS. Based on observations made with the ESO telescopes at the La Silla or Paranal Observatories under proposal IDs 171.A-0486 and 176.A-0589. NR 34 TC 70 Z9 71 U1 0 U2 1 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 AUG 20 PY 2008 VL 683 IS 2 BP L131 EP L134 DI 10.1086/591647 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 340BR UT WOS:000258621600010 ER PT J AU Jang-Condell, H Mugrauer, M Schmidt, T AF Jang-Condell, H. Mugrauer, M. Schmidt, T. TI Disk truncation and planet formation in gamma Cephei SO ASTROPHYSICAL JOURNAL LETTERS LA English DT Article DE accretion, accretion disks; binaries : close; planetary systems; planetary systems : formation; planetary systems : protoplanetary disks; stars : individual (gamma Cephei) ID TRIPLE-STAR SYSTEM; ACCRETION DISKS; BINARY-SYSTEMS; GIANT PLANET; HOST STARS; COMPANIONS; MASS; MULTIPLICITY; PROTOPLANETS; CONSTRAINTS AB The gamma Cephei system is one of the most closely bound binary planet hosts known to date. The companion (gamma Cep B) to the planet-hosting star (gamma Cep A) should have truncated any protoplanetary disk around gamma Cep A, possibly limiting planet formation in the disk. We explore this problem by calculating the truncation radii of protoplanetary disk models around gamma Cep A to determine whether or not there is sufficient material remaining in the disk to form a planet. We vary the accretion rate and viscosity parameter of the disk models to cover a range of reasonable possibilities for the disk properties and determine that for accretion rates of >= 10(-7) M(circle dot) yr(-1) and low viscosity parameter, sufficient material in gas and solids exist for planet formation via core accretion to be possible. Disk instability is less favored, as this can only occur in the most massive disk model with an extremely high accretion rate. C1 [Jang-Condell, H.] Univ Maryland, Dept Astron, College Pk, MD 20742 USA. [Jang-Condell, H.] NASA, Goddard Space Flight Ctr, Exoplanets & Stellar Astrophys Lab, Greenbelt, MD 20771 USA. [Mugrauer, M.; Schmidt, T.] Inst Astrophys, D-07745 Jena, Germany. [Mugrauer, M.; Schmidt, T.] Univ Jena, Univ Sternwarte, D-07745 Jena, Germany. RP Jang-Condell, H (reprint author), Univ Maryland, Dept Astron, College Pk, MD 20742 USA. EM hannah@astro.umd.edu OI Jang-Condell, Hannah/0000-0002-7639-1322 FU NASA Astrobiology Institute [NNA04CC09A]; Michelson Fellowship; Jet Propulsion Laboratory (JPL) FX H. J.-C. acknowledges support by the NASA Astrobiology Institute under Cooperative Agreement NNA04CC09A at the Carnegie Institution of Washington, Department of Terrestrial Magnetism. H. J.- C. also acknowledges support from a Michelson Fellowship: this work was performed in part under contract with the Jet Propulsion Laboratory (JPL) funded by NASA through the Michelson Fellowship Program. JPL is managed for NASA by the California Institute of Technology. T. S. acknowledges support from Evangelisches Studienwerk e. V. Villigst. NR 34 TC 11 Z9 11 U1 0 U2 1 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 AUG 20 PY 2008 VL 683 IS 2 BP L191 EP L194 DI 10.1086/591791 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 340BR UT WOS:000258621600025 ER PT J AU Trilling, DE Mueller, M Hora, JL Fazio, G Spahr, T Stansberry, JA Smith, HA Chesley, SR Mainzer, AK AF Trilling, D. E. Mueller, M. Hora, J. L. Fazio, G. Spahr, T. Stansberry, J. A. Smith, H. A. Chesley, S. R. Mainzer, A. K. TI Diameters and albedos of three subkilometer near-earth objects derived from Spitzer observations SO ASTROPHYSICAL JOURNAL LETTERS LA English DT Article DE infrared : solar system; minor planets, asteroids ID INFRARED ARRAY CAMERA; SPACE-TELESCOPE; THERMAL-MODEL; ASTEROIDS; POPULATION; SIZE AB Near-Earth objects (NEOs)are fragments of remnant primitive bodies that date from the era of solar system formation. At present, the physical properties and origins of NEOs are poorly understood. We have measured thermal emission from three NEOs-(6037) 1988 EG, 1993 GD, and 2005 GL-with Spitzer's IRAC instrument at 3.6, 4.5, 5.8, and 8.0 mu m (the last object was detected only at 5.8 and 8.0 mu m). The diameters of these three objects are 400, 180, and 160 m, respectively, with uncertainties of around 20% (including both observational and systematic errors). For all three the geometric albedos are around 0.30, in agreement with previous results that most NEOs are S-class asteroids. For the two objects detected at 3.6 and 4.5 mu m, diameters and albedos based only on those data agree with the values based on modeling the data in all four bands. This agreement, and the high sensitivity of IRAC, shows the promise of the Spitzer Warm Mission for determining the physical parameters for a large number of NEOs. C1 [Trilling, D. E.; Mueller, M.; Stansberry, J. A.] Steward Observ, Tucson, AZ 85721 USA. [Hora, J. L.; Fazio, G.; Spahr, T.; Smith, H. A.] Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. [Chesley, S. R.; Mainzer, A. K.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Trilling, DE (reprint author), Steward Observ, 933 N Cherry Ave, Tucson, AZ 85721 USA. EM trilling@as.arizona.edu OI Mueller, Michael/0000-0003-3217-5385; Hora, Joseph/0000-0002-5599-4650 NR 22 TC 7 Z9 7 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA J9 ASTROPHYS J LETT JI Astrophys. J. Lett. PD AUG 20 PY 2008 VL 683 IS 2 BP L199 EP L202 DI 10.1086/591668 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 340BR UT WOS:000258621600027 ER PT J AU Wisniewski, JP Clampin, M Bjorkman, KS Barry, RK AF Wisniewski, John P. Clampin, Mark Bjorkman, Karen S. Barry, Richard K. TI High spatial resolution mid-IR imaging of V838 monocerotis: Evidence of new circumstellar dust creation SO ASTROPHYSICAL JOURNAL LETTERS LA English DT Article DE circumstellar matter; stars : individual (V838 Monocerotis) ID LIGHT-ECHO; MODEL; PROGENITOR; EVOLUTION; EMISSION; DISTANCE; MON AB We report high spatial resolution 11.2 and 18.1 mu m imaging of V838 Monocerotis obtained with Gemini Observatory's Michelle instrument in 2007 March. Strong emission is observed from the unresolved stellar core of V838 Mon in our Gemini imagery and is confirmed by Spitzer MIPS 24 mu m imaging obtained in 2007 April. The 2007 flux density of the unresolved mid- infrared emission component is mu m 2 times brighter than that observed in 2004. No clear change in the net amount of 24 mm extended emission is observed between the 2004 and 2007 epoch Spitzer imagery. We interpret these data as evidence that V838 Mon has experienced a new circumstellar dust creation event. We suggest that this newly created dust has condensed from the expanding ejecta produced from V838 Mon's 2002 outburst events and is most likely clumpy. We speculate that one (or more) of these clumps might have passed through the line of sight in late 2006, producing the brief multiwavelength photometric event reported by H. Bond in 2006 and U. Munari et al. in 2007b. We detect no evidence of extended emisssion above a level of similar to 1 mJy at 11.2 mu m and similar to 7 mJy at 18.1 mu m over radial distances of 1860-93,000 AU (0.3 ''-15.0 '') from the central source. Using the simple assumption that ejecta material expands at a constant velocity of 300-500 km s(-1), this gap of thermal emission suggests that no significant prior circumstellar dust production events have occurred within the past similar to 900-1500 yr. C1 [Wisniewski, John P.; Clampin, Mark; Barry, Richard K.] NASA, Goddard Space Flight Ctr, Exoplanets & Stellar Astrophys Lab, Greenbelt, MD 20771 USA. [Bjorkman, Karen S.] Univ Toledo, Dept Phys & Astron, Toledo, OH 43606 USA. EM jwisnie@u.washington.edu; Mark.Clampin@nasa.gov; Karen.Bjorkman@utoledo.edu; Richard.K.Barry@nasa.gov RI Clampin, mark/D-2738-2012 FU NASA [NNH06CC03B] FX We thank H. Bond, B. Bonev, M. Perrin, A. Roberge, and K. Volk for helpful discussions about our data and our annonymous referee for providing feedback which helped to improve this Letter. Support for this project was provided by a NASA NPP fellowship to JPW (NNH06CC03B). NR 27 TC 6 Z9 6 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA J9 ASTROPHYS J LETT JI Astrophys. J. Lett. PD AUG 20 PY 2008 VL 683 IS 2 BP L171 EP L174 DI 10.1086/591735 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 340BR UT WOS:000258621600020 ER PT J AU Zepf, SE Stern, D Maccarone, TJ Kundu, A Kamionkowski, M Rhode, KL Salzer, JJ Ciardullo, R Gronwall, C AF Zepf, Stephen E. Stern, Daniel Maccarone, Thomas J. Kundu, Arunav Kamionkowski, Marc Rhode, Katherine L. Salzer, John J. Ciardullo, Robin Gronwall, Caryl TI Very broad [O III] lambda lambda 4959, 5007 emission from the NGC 4472 globular cluster RZ 2109 and implications for the mass of its black hole X-ray source SO ASTROPHYSICAL JOURNAL LETTERS LA English DT Article DE galaxies : individual (NGC 4472); galaxies : star clusters; globular clusters : general; X-rays : binaries; X-rays : galaxies : clusters ID STAR-CLUSTERS; RESOLUTION; NGC-1068; SPECTROMETER; SPECTRA; RATIO AB We present Keck LRIS spectroscopy of the black hole -hosting globular cluster RZ 2109 in the Virgo elliptical galaxy NGC 4472. We find that this object has extraordinarily broad [O III] lambda 5007 and [O III] lambda 4959 emission lines, with velocity widths of approximately 2000 km s(-1). This result has significant implications for the nature of this accreting black hole system and the mass of the globular cluster black hole. We show that the broad [O III] lambda 5007 emission must arise from material driven at high velocity from the black hole system. This is because the volume available near the black hole is too small by many orders of magnitude to have enough [O III]-emitting atoms to account for the observed L([O III] lambda 5007) at high velocities, even if this volume is filled with oxygen at the critical density for [O III] lambda 5007. The Balmer emission is also weak, indicating the observed [O III] is not due to shocks. We therefore conclude that the [O III] lambda lambda 4959, 5007 is produced by photoionization of material driven across the cluster. The only known way to drive significant material at high velocity is for a system accreting mass near or above its Eddington limit, which indicates a stellar-mass black hole. Since it is dynamically implausible to form an accreting stellar-mass black hole system in a globular cluster with an intermediate-mass black hole (IMBH), it appears this massive globular cluster does not have an IMBH. We discuss further tests of this conclusion, and its implications for the and relations. C1 [Zepf, Stephen E.; Kundu, Arunav] Michigan State Univ, Dept Phys & Astron, E Lansing, MI 48824 USA. [Stern, Daniel] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Maccarone, Thomas J.] Univ Southampton, Sch Phys & Astron, Southampton SO17 1BJ, Hants, England. [Kamionkowski, Marc] CALTECH, Pasadena, CA 91125 USA. [Rhode, Katherine L.; Salzer, John J.] Indiana Univ, Dept Astron, Bloomington, IN 47405 USA. [Salzer, John J.] Wesleyan Univ, Dept Astron, Middletown, CT 06459 USA. [Ciardullo, Robin; Gronwall, Caryl] Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA. RP Zepf, SE (reprint author), Michigan State Univ, Dept Phys & Astron, E Lansing, MI 48824 USA. EM zepf@pa.msu.edu; stern@zwolfkinder.jpl.nasa.gov; tjm@astro.soton.ac.uk; akundu@pa.msu.edu; kamion@tapir.caltech.edu; rhode@astro.indiana.edu; slaz@astro.indiana.edu; rbc@astro.psu.edu; caryl@astro.psu.edu FU NSF [AST 04-06891]; NASA-LTSA [NAG5-12975] FX S. E. Z. acknowledges support for this work from NSF award AST 04-06891, A. K. acknowledges support from NASA-LTSA grant NAG5-12975, and the work of D. S. was carried out at Jet Propulsion Laboratory, California Institute of Technology, under a contract with NASA. We also thank the referee for a detailed and careful report. We wish to acknowledge the significant cultural role that the summit of Mauna Kea plays within the indigenous Hawaiian community; we are fortunate to have the opportunity to conduct observations from this mountain. NR 25 TC 33 Z9 33 U1 0 U2 1 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 AUG 20 PY 2008 VL 683 IS 2 BP L139 EP L142 DI 10.1086/591937 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 340BR UT WOS:000258621600012 ER PT J AU Krueger, A Krotkov, N Carn, S AF Krueger, Arlin Krotkov, Nickolay Carn, Simon TI El Chichon: The genesis of volcanic sulfur dioxide monitoring from space SO JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH LA English DT Article DE volcanism; explosive eruptions; sulfur dioxide; remote sensing; El Chichon; TOMS ID OZONE MAPPING SPECTROMETER; SATELLITE MEASUREMENTS; 1982 ERUPTIONS; DUST CLOUD; ULTRAVIOLET; MEXICO; TOMS; DEPOSITS; AEROSOL; SO2 AB The 1982 eruption of El Chichon inspired a new technique for monitoring volcanic clouds. Data from the Total Ozone Mapping Spectrometer (TOMS) instrument on the Nimbus-7 satellite were used to measure sulfur dioxide in addition to ozone. For the first time precise data on the sulfur dioxide mass in even the largest explosive eruption plumes could be determined. The plumes could be tracked globally as they are carried by winds. Magmatic eruptions could be discriminated from phreatic eruptions. The data from El Chichon are reanalyzed in this paper using the latest version of the TOMS instrument calibration (W). They show the shearing of the eruption cloud into a globe-circling band while still anchored over Mexico in three weeks. The measured sulfur dioxide mass in the initial March 28 eruption was 1.6 Tg; the April 3 eruption produced 0.3 Tg more, and the April 4 eruptions added 5.6 Tg, for a cumulative total of 7.5 Tg, in substantial agreement with estimates from prior data versions. TOMS Aerosol Index (absorbing aerosol) data show rapid fallout of dense ash east and south of the volcano in agreement with Advanced Very High Resolution Radiometer (AVHRR) ash cloud positions. (C) 2008 Elsevier B.V. All rights reserved. C1 [Krueger, Arlin; Carn, Simon] Univ Maryland, Joint Ctr Earth Syst Technol, Baltimore, MD 21250 USA. [Krotkov, Nickolay] Univ Maryland, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21250 USA. RP Krueger, A (reprint author), Univ Maryland, Joint Ctr Earth Syst Technol, 1000 Hilltop Circle, Baltimore, MD 21250 USA. EM akrueger@umbc.edu RI Krotkov, Nickolay/E-1541-2012 OI Krotkov, Nickolay/0000-0001-6170-6750 NR 27 TC 25 Z9 25 U1 0 U2 9 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 AUG 20 PY 2008 VL 175 IS 4 SI SI BP 408 EP 414 DI 10.1016/j.jvolgeores.2008.02.026 PG 7 WC Geosciences, Multidisciplinary SC Geology GA 357GT UT WOS:000259835000004 ER PT J AU Rizzi, SA Przekop, A AF Rizzi, Stephen A. Przekop, Adam TI System identification-guided basis selection for reduced-order nonlinear response analysis SO JOURNAL OF SOUND AND VIBRATION LA English DT Article; Proceedings Paper CT EUROMECH Colloquium on Geometrically Non-Linear Vibrations of Structures CY JUL 09-11, 2007 CL Univ Porto, Fac Engn, Porto, PORTUGAL HO Univ Porto, Fac Engn AB Reduced-order nonlinear simulation is often times the only computationally efficient means of calculating the extended time response of large and complex structures under severe dynamic loading. This is because the structure may respond in a geometrically nonlinear manner, making the computational expense of direct numerical integration in physical degrees of freedom prohibitive. As for any type of modal reduction scheme, the quality of the reduced-order solution is dictated by the modal basis selection. The techniques for modal basis selection currently employed for nonlinear simulation are ad hoc and are strongly influenced by the analyst's subjective judgment. This work develops a reliable and rigorous procedure through which an efficient modal basis can be chosen. The method employs proper orthogonal decomposition to identify nonlinear system dynamics, and the modal assurance criterion to relate proper orthogonal modes to the normal modes that are eventually used as the basis functions. The method is successfully applied to the analysis of a planar beam and a shallow arch over a wide range of nonlinear dynamic response regimes. The error associated with the reduced-order simulation is quantified and related to the computational cost. Published by Elsevier Ltd. C1 [Rizzi, Stephen A.] NASA, Langley Res Ctr, Struct Acoust Branch, Hampton, VA 23681 USA. [Przekop, Adam] Natl Inst Aerosp, Hampton, VA 23666 USA. RP Rizzi, SA (reprint author), NASA, Langley Res Ctr, Struct Acoust Branch, Hampton, VA 23681 USA. EM stephen.a.rizzi@nasa.gov NR 25 TC 16 Z9 16 U1 2 U2 5 PU ACADEMIC PRESS LTD ELSEVIER SCIENCE LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0022-460X J9 J SOUND VIB JI J. Sound Vibr. PD AUG 19 PY 2008 VL 315 IS 3 BP 467 EP 485 DI 10.1016/j.jsv.2007.12.031 PG 19 WC Acoustics; Engineering, Mechanical; Mechanics SC Acoustics; Engineering; Mechanics GA 324KG UT WOS:000257516900007 ER PT J AU Bilitza, D Reinisch, BW AF Bilitza, D. Reinisch, B. W. TI International Reference Ionosphere 2007: Improvements and new parameters SO ADVANCES IN SPACE RESEARCH LA English DT Article DE ionosphere; IRI; global ionospheric models ID ELECTRON-DENSITY PROFILES; TOPSIDE SOUNDER DATA; EMPIRICAL-MODEL; IRI; PLASMASPHERE; TEMPERATURE; IMAGE/RPI AB International Reference Ionosphere (IRI), a joint project of URSI and COSPAR, is the de facto international standard for the climatological specification of ionospheric parameters and as such it is currently undergoing registration as Technical Specification (TS) of the International Standardization Organization (ISO). IRI by charter and design is an empirical model based on a wide range of ground and space data. It describes monthly averages of ionospheric densities and temperatures in the altitude range 50-1500 km in the non-auroral ionosphere. Since its inception in 1969 the IRI model has been steadily improved with newer data and with better mathematical descriptions of global and temporal variation patterns. A large number of independent studies have validated the IRI model in comparisons with direct and indirect ionospheric measurements not used in the model development. A comparison with IRI is often one of the first science tasks by an ionospheric satellite or rocket team. This paper describes the latest version of the IRI model, IRI-2007, explaining the most important changes that are being introduced with this version. These include: (1) two new options for the topside electron density, (2) a new model for the topside ion composition, (3) the first-time inclusion of a model for the spread F occurrence probability, (4) a NeuralNet model for auroral E-region electron densities, (5) a model for the plasmaspheric electron temperature, and (6) the latest International Geomagnetic Reference Field (IGRF) model for the computation of magnetic coordinates including their changes due to the secular variation of the magnetic field. (c) 2008 COSPAR. Published by Elsevier Ltd. All rights reserved. C1 [Bilitza, D.] SPDF, GSFC, Greenbelt, MD 20771 USA. [Bilitza, D.] George Mason Univ, Fairfax, VA 22030 USA. [Reinisch, B. W.] Univ Massachusetts, Ctr Atmospher Res, Lowell, MA USA. RP Bilitza, D (reprint author), SPDF, GSFC, Code 672, Greenbelt, MD 20771 USA. EM dieter.bilitza-1@nasa.gov NR 47 TC 478 Z9 516 U1 5 U2 41 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 AUG 18 PY 2008 VL 42 IS 4 BP 599 EP 609 DI 10.1016/j.asr.2007.07.048 PG 11 WC Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA 333BM UT WOS:000258127000001 ER PT J AU Schmidt, M Bilitza, D Shum, CK Zeilhofer, C AF Schmidt, M. Bilitza, D. Shum, C. K. Zeilhofer, C. TI Regional 4-D modeling of the ionospheric electron density SO ADVANCES IN SPACE RESEARCH LA English DT Article DE electron density; B-splines; multi-resolution representation; empirical orthogonal functions ID TOMOGRAPHY; WAVELETS AB The knowledge of the electron density is the key point in correcting ionospheric delays of electromagnetic measurements and in studying the ionosphere. During the last decade GNSS, in particular GPS, has become a promising tool for monitoring the total electron content (TEC), i.e., the integral of the electron density along the ray-path between the transmitting satellite and the receiver. Hence, geometry-free GNSS measurements provide informations on the electron density, which is basically a four-dimensional function depending on spatial position and time. In addition, these GNSS measurements can be combined with other available data including nadir, over-ocean TEC observations from dual-frequency radar altimetry (T/P, JASON, ENVISAT), and TECs from GPS-LEO occultation systems (e.g., FORMOSAT-3/COSMIC, CHAMP) with heterogeneous sampling and accuracy. In this paper, we present different multi-dimensional approaches for modeling spatio-temporal variations of the ionospheric electron density. To be more specific, we split the target function into a reference part, computed from the International Reference Ionosphere (IRI), and an unknown correction term. Due to the localizing feature of B-spline functions we apply tensor-product spline expansions to model the correction term in a certain multi-dimensional region either completely or partly. Furthermore, the multi-resolution representation derived from wavelet analysis allows monitoring the ionosphere at different resolutions levels. For demonstration we apply three approaches to electron density data over South America. (C) 2007 COSPAR. Published by Elsevier Ltd. All rights reserved. C1 [Schmidt, M.; Zeilhofer, C.] Deutsches Geodatisches Forschungsinst, D-80539 Munich, Germany. [Bilitza, D.] SPDF, NASA Goddard Space Flight Ctr, Raytheon ITSS, Greenbelt, MD USA. [Shum, C. K.] Ohio State Univ, Sch Earth Sci, Columbus, OH 43210 USA. RP Schmidt, M (reprint author), Deutsches Geodatisches Forschungsinst, Alfons Goppel Str 11, D-80539 Munich, Germany. EM schmidt@dgfi.badw.de; dieter.bilitza.1@gsfc.nasa.gov; ckshum@osu.edu; zeilhofer@dgfi.badw.de NR 19 TC 28 Z9 28 U1 0 U2 6 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 AUG 18 PY 2008 VL 42 IS 4 BP 782 EP 790 DI 10.1016/j.asr.2007.02.050 PG 9 WC Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA 333BM UT WOS:000258127000026 ER PT J AU Mouroulis, P AF Mouroulis, Pantazis TI Depth of field extension with spherical optics SO OPTICS EXPRESS LA English DT Article ID EXTENDED DEPTH; FOCAL DEPTH; MODULATION; SYSTEMS AB The introduction of spherical aberration in a lens design can be used to extend the depth of field while preserving resolution up to half the maximum diffraction-limited spatial frequency. Two low-power microscope objectives are shown that achieve an extension of +/- 0.88 lambda in terms of wavefront error, which is shown to be comparable to alternative techniques but without the use of special phase elements. The lens performance is azimuth-independent and achromatic over the visible range. (C) 2008 Optical Society of America. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Mouroulis, P (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM pantazis.mouroulis@jpl.nasa.gov NR 17 TC 29 Z9 29 U1 0 U2 7 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1094-4087 J9 OPT EXPRESS JI Opt. Express PD AUG 18 PY 2008 VL 16 IS 17 BP 12995 EP 13004 DI 10.1364/OE.16.012995 PG 10 WC Optics SC Optics GA 349GG UT WOS:000259268700060 PM 18711538 ER PT J AU Brown, TR Hylton, D Mintz, EA Ingram, C James, C Whigham, A Chuang, KC AF Brown, T. Renee Hylton, Donald Mintz, Enic A. Ingram, Conrad James, Candace Whigham, Aujanae Chuang, Kathy C. TI INOR 609-The effect of cation-exchanging K plus to Na plus and H plus in zeolite L on the rate of cure and thermoxidative stability of GRC-A/zeolite PMCs SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 236th National Meeting of the American-Chemical-Society CY AUG 17-21, 2008 CL Philadelphia, PA SP Amer Chem Soc C1 [Brown, T. Renee; Hylton, Donald; Mintz, Enic A.; Ingram, Conrad; James, Candace; Whigham, Aujanae] Clark Atlanta Univ, High Performance Polymers & Composites Ctr, Atlanta, GA 30314 USA. [Brown, T. Renee; Hylton, Donald; Mintz, Enic A.; Ingram, Conrad; James, Candace; Whigham, Aujanae] Clark Atlanta Univ, Dept Chem, Atlanta, GA 30314 USA. [Chuang, Kathy C.] NASA Glenn Res Ctr, Cleveland, OH 44135 USA. EM trbrown77@hotmail.com NR 0 TC 0 Z9 0 U1 1 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 17 PY 2008 VL 236 MA 609-INOR PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 499WD UT WOS:000270256306770 ER PT J AU Cable, ML Kirby, JP Levine, DJ Manary, MJ Gray, HB Ponce, A AF Cable, Morgan L. Kirby, James P. Levine, Dana J. Manary, Micah J. Gray, Harry B. Ponce, Adrian TI INOR 139-Bacterial spore detection: Construction of a lanthanide-based molecular receptor site SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 236th National Meeting of the American-Chemical-Society CY AUG 17-21, 2008 CL Philadelphia, PA SP Amer Chem Soc C1 [Cable, Morgan L.; Levine, Dana J.; Manary, Micah J.; Gray, Harry B.] CALTECH, Pasadena, CA 91125 USA. [Kirby, James P.; Ponce, Adrian] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. EM dlevine@caltech.edu; manary@caltech.edu; Adrian.Ponce@jpl.nasa.gov NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 17 PY 2008 VL 236 MA 139-INOR PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 499WD UT WOS:000270256306591 ER PT J AU Chandrasekhar, P Zay, BJ Barbolt, S Werner, R Birur, GC Paris, A AF Chandrasekhar, Prasanna Zay, Brian J. Barbolt, Scott Werner, Robert Birur, Gajanana C. Paris, Anthony TI PMSE 146-High performance variable emittance devices for spacecraft application based on conducting polymers coupled with ionic liquids SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 236th National Meeting of the American-Chemical-Society CY AUG 17-21, 2008 CL Philadelphia, PA SP Amer Chem Soc C1 [Chandrasekhar, Prasanna; Zay, Brian J.; Barbolt, Scott; Werner, Robert] Ashwin Ushas Corp Inc, Lakewood, NJ 08701 USA. [Birur, Gajanana C.; Paris, Anthony] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. EM chandra.p2@ashwin-ushas.com; zay.b.2@ashwin-ushas.com; hro@ashwin-ushas.com; hro@ashwin-ushas.com; hro@ashwin-ushas.com; hro@ashwin-ushas.com NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 17 PY 2008 VL 236 MA 146-PMSE PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 500EC UT WOS:000270280001093 ER PT J AU Hurwitz, FI Aranda, DV AF Hurwitz, Frances I. Aranda, Denisse V. TI POLY 536-Aerogels in the Al2O3-SiO2 system SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 236th National Meeting of the American-Chemical-Society CY AUG 17-21, 2008 CL Philadelphia, PA SP Amer Chem Soc C1 [Hurwitz, Frances I.] NASA, Struct & Mat Div, Glenn Res Ctr, Cleveland, OH 44135 USA. [Aranda, Denisse V.] Florida Int Univ, Miami, FL 33199 USA. EM frances.hurwitz@nasa.gov NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 17 PY 2008 VL 236 MA 536-POLY PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 499WD UT WOS:000270256308109 ER PT J AU Hwang, SJ Kim, C Bowman, R Reiter, J Zan, J Purewal, J AF Hwang, Son-Jong Kim, Chul Bowman, Robert Reiter, Joseph Zan, Jason Purewal, Justin TI PHYS 55-Characterization of metal tetrahydroborate systems by high resolution multinuclear solid state NMR SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 236th National Meeting of the American-Chemical-Society CY AUG 17-21, 2008 CL Philadelphia, PA SP Amer Chem Soc C1 [Hwang, Son-Jong; Kim, Chul] CALTECH, Dept Chem & Chem Engn, Pasadena, CA 91125 USA. [Bowman, Robert; Reiter, Joseph; Zan, Jason] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Purewal, Justin] CALTECH, Div Engn & Appl Sci, Pasadena, CA 91125 USA. EM sonjong@cheme.caltech.edu; chulkim@caltech.edu; rbowman@jpl.nasa.gov; Joseph.W.Reiter@jpl.nasa.gov; Jason.A.Zan@jpl.nasa.gov NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 17 PY 2008 VL 236 MA 55-PHYS PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 499WD UT WOS:000270256307545 ER PT J AU Levine, DJ Cable, ML Kirby, JP Manary, MJ Gray, HB Ponce, A AF Levine, Dana J. Cable, Morgan L. Kirby, James P. Manary, Micah J. Gray, Harry B. Ponce, Adrian TI CHED 223-Use of lanthanide-macrocycle platforms for the detection of dipicolinate and other analytes SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 236th National Meeting of the American-Chemical-Society CY AUG 17-21, 2008 CL Philadelphia, PA SP Amer Chem Soc C1 [Levine, Dana J.; Cable, Morgan L.; Manary, Micah J.; Gray, Harry B.] CALTECH, Pasadena, CA 91125 USA. [Kirby, James P.; Ponce, Adrian] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. EM dlevine@caltech.edu; manary@caltech.edu; Adrian.Ponce@jpl.nasa.gov NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 17 PY 2008 VL 236 MA 223-CHED PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 499WD UT WOS:000270256303389 ER PT J AU Meador, MAB Weber, AS Hindi, A Deshpande, K White, S Gould, G AF Meador, Mary Ann B. Weber, Amanda S. Hindi, Alia Deshpande, Kirinmayi White, Shannon Gould, George TI POLY 296-Adapting polymer cross-linking of silica based aerogels to a safer, industry friendly process SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 236th National Meeting of the American-Chemical-Society CY AUG 17-21, 2008 CL Philadelphia, PA SP Amer Chem Soc C1 [Meador, Mary Ann B.; Hindi, Alia] NASA, Glenn Res Ctr, Mat & Struct Div, Cleveland, OH 44135 USA. [Weber, Amanda S.] Univ S Dakota, Dept Chem, Vermillion, SD 57069 USA. [Deshpande, Kirinmayi; White, Shannon; Gould, George] Aspen Aerogels Inc, Northborough, MA 01532 USA. EM maryann.meador@nasa.gov; Amanda.Weber@usd.edu; alia.hindi@nasa.gov; kdeshpande@aerogel.com; swhite@aerogel.com; ggould@aerogel.com NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 17 PY 2008 VL 236 MA 296-POLY PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 499WD UT WOS:000270256308141 ER PT J AU Randall, JP Meador, MAB Jana, SC AF Randall, Jason P. Meador, Mary Ann B. Jana, Sadhan C. TI POLY 450-Evaluating dimethyldiethoxysilane in polyurethane crosslinked silica aerogels SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 236th National Meeting of the American-Chemical-Society CY AUG 17-21, 2008 CL Philadelphia, PA SP Amer Chem Soc C1 [Randall, Jason P.; Jana, Sadhan C.] Univ Akron, Dept Polymer Engn, Akron, OH 44325 USA. [Meador, Mary Ann B.] NASA, Mat & Struct Div, Glenn Res Ctr, Cleveland, OH 44135 USA. EM jason.p.randall@nasa.gov; maryann.meador@nasa.gov; janas@uakron.edu NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 17 PY 2008 VL 236 MA 450-POLY PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 499WD UT WOS:000270256308225 ER PT J AU Van Wyngarden, AL Iraci, LT AF Van Wyngarden, Annalise L. Iraci, Laura T. TI NUCL 29-Organic chemistry in atmospheric particles: Implications for climate change SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 236th National Meeting of the American-Chemical-Society CY AUG 17-21, 2008 CL Philadelphia, PA SP Amer Chem Soc C1 [Van Wyngarden, Annalise L.] NASA, Ames Res Ctr, Atmospher Sci Branch, Moffett Field, CA 94035 USA. [Iraci, Laura T.] NASA, Ames Res Ctr, Div Earth Sci, Moffett Field, CA 94035 USA. EM Annalise.L.VanWyngarden@nasa.gov; laura.t.iraci@nasa.gov NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 17 PY 2008 VL 236 MA 29-NUCL PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 499WD UT WOS:000270256305760 ER PT J AU Vander Wal, RL Bryg, VM Hays, MD AF Vander Wal, Randall L. Bryg, Vicky M. Hays, Michael D. TI FUEL 143-Combustion produced carbonaceous particulate: Chemical composition and physical nanostructure SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 236th National Meeting of the American-Chemical-Society CY AUG 17-21, 2008 CL Philadelphia, PA SP Amer Chem Soc C1 [Vander Wal, Randall L.; Bryg, Vicky M.] NASA Glenn, USRA, Cleveland, OH 44135 USA. [Hays, Michael D.] US EPA, Natl Risk Management Res Lab, Res Triangle Pk, NC 27711 USA. EM Randall.L.VanderWal@grc.nasa.gov; hays.michael@epamail.epa.gov NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 17 PY 2008 VL 236 MA 143-FUEL PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 499WD UT WOS:000270256304624 ER PT J AU Vivod, SL Meador, MAB Nguyen, BN Quade, DJ Randall, JP AF Vivod, Stephanie L. Meador, Mary Ann B. Nguyen, Baochau N. Quade, Derek J. Randall, Jason P. TI POLY 449-Di-isocyanate crosslinked aerogels with 1,6-bis(trimethoxysilyl)hexane incorporated in silica backbone SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 236th National Meeting of the American-Chemical-Society CY AUG 17-21, 2008 CL Philadelphia, PA SP Amer Chem Soc C1 [Vivod, Stephanie L.; Meador, Mary Ann B.; Quade, Derek J.] NASA, Mat & Struct Div, Glenn Res Ctr, Cleveland, OH 44135 USA. [Nguyen, Baochau N.] Ohio Aerosp Inst, Cleveland, OH 44135 USA. [Randall, Jason P.] Univ Akron, Dept Polymer Engn, Akron, OH 44325 USA. EM Stephanie.L.Vivod@nasa.gov; maryann.meador@nasa.gov; baochau.n.nguyen@nasa.gov; jason.p.randall@nasa.gov NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD AUG 17 PY 2008 VL 236 MA 449-POLY PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 499WD UT WOS:000270256308117 ER PT J AU Brown, D Worden, J Noone, D AF Brown, Derek Worden, John Noone, David TI Comparison of atmospheric hydrology over convective continental regions using water vapor isotope measurements from space SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID STABLE-ISOTOPES; OXYGEN-ISOTOPE; AMAZON BASIN; PRECIPITATION; CLIMATE; SURFACE; CYCLE; ICE; DRY; TEMPERATURE AB [1] Global measurements of the 500-825 hPa layer mean HDO/H2O ratio from the Tropospheric Emission Spectrometer (TES) are used to expose differences in the dominant hydrologic processes in the Amazon, north Australian, and Asian monsoon regions. The data show high regional isotopic variability and numerous values unexpected from classical Rayleigh theory. Correlation analysis shows that mixing with boundary layer air, enhanced isotopic fractionation during precipitation, and subsiding air parcels contribute to intraseasonal isotopic variability. These local controls explain only 8-30% of total regional variance, which suggests that the isotopes are primarily indicators of moist processes that occur upstream. Seasonal trajectory analysis demonstrates that Rayleigh distillation in a Lagrangrian framework underestimates the observed isotopic depletion during the monsoons and suggests substantial recycling of water within or below clouds. The trajectory results for the dry seasons reveal that subsiding air parcels periodically introduce isotopically depleted air into the north Australia and Asian monsoon regions, whereas vigorous low-level convection over the Amazon basin acts to quickly enrich and moisten dry subsiding air. The analysis indicates variations in the strength of convective detrainment into the lower to middle troposphere over all regions, which, during the dry seasons of the north Australian and Asian monsoon regions, correlate with increases in relative humidity. This study shows that isotopic measurements provide unique diagnostics of mechanisms that control the seasonal sources of water and that these provide a refined understanding of the differences in the characteristics of hydrologic budgets in these monsoonal regions. C1 [Brown, Derek; Noone, David] Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. [Brown, Derek; Noone, David] Univ Colorado, Dept Atmospher & Ocean Sci, Boulder, CO 80309 USA. [Worden, John] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Brown, D (reprint author), Univ Colorado, Cooperat Inst Res Environm Sci, Campus Box 216, Boulder, CO 80309 USA. EM derek.brown@colorado.edu FU U.S. Department of Energy's Office of Biological and Environmental Research; Jet Propulsion Laboratory; National Aeronautics and Space Administration FX The authors would like to thank Manvendra Dubey at Los Alamos National Laboratory for his encouragement of this work and Kevin Bowman at NASA's Jet Propulsion Laboratory for assisting with development of the TES HDO product. Support for this study came from a Graduate Research Environmental Fellowship from the U.S. Department of Energy's Office of Biological and Environmental Research and funding from the Jet Propulsion Laboratory. A portion of 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 38 TC 40 Z9 42 U1 0 U2 18 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 AUG 15 PY 2008 VL 113 IS D15 AR D15124 DI 10.1029/2007JD009676 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 338MA UT WOS:000258510800004 ER PT J AU van Diedenhoven, B Hasekamp, OP Landgraf, J AF van Diedenhoven, B. Hasekamp, O. P. Landgraf, J. TI Effects of clouds on ozone profile retrievals from satellite measurements in the ultraviolet SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID RADIATIVE-TRANSFER MODEL; PERTURBATION-THEORY APPROACH; MONITORING-EXPERIMENT GOME; ABSORPTION CROSS-SECTIONS; TROPOSPHERIC OZONE; REGULARIZATION; ATMOSPHERES; SCATTERING; ALGORITHM; SPACE AB [1] We evaluated a new approach to take clouds into account in ozone profile retrievals from backscattered ultraviolet radiance measurements as performed by the Global Ozone Monitoring Experiment (GOME). In this approach ozone profiles are retrieved using cloud fractions, cloud optical thicknesses and top pressures retrieved from oxygen A-band measurements combined with measurements between 350 nm and 390 nm. This approach (CUVO2), is compared with two commonly used approaches in ozone profile retrievals, namely to treat clouds as an effective ground surface albedo (CaA); and using effective cloud fractions and top pressures retrieved from the oxygen A-band by assuming a cloud optical thickness of 40 (Ceff). Using simulated GOME retrievals we show that the CaA and Ceff approaches lead to significant biases in the mean ozone concentrations of up to -85% and 18% near the surface, respectively. With the CUVO2 approach these errors are reduced to below 3%. Retrievals from 233 GOME measurements using the three approaches were validated with ozonesonde measurements at 5 different locations. For most cases the results are as expected from the simulations. For scenes with strong indications for the presence of inhomogeneous clouds, all studied approaches do not correct for cloud sufficiently. The standard deviation of the differences between retrieved profiles and sonde sonde profiles is about 2.5 times larger in the troposphere than expected from the simulations, which indicates that other error sources than clouds dominate the variation in retrieval and/or validation. C1 [van Diedenhoven, B.] NASA, Goddard Inst Space Studies, New York, NY 10025 USA. [Hasekamp, O. P.; Landgraf, J.] SRON, Netherlands Inst Space Res, Earth Oriented Sci Div, NL-3584 CA Utrecht, Netherlands. RP van Diedenhoven, B (reprint author), NASA, Goddard Inst Space Studies, 2880 Broadway, New York, NY 10025 USA. EM bvandiedenhoven@giss.nasa.gov RI van Diedenhoven, Bastiaan/A-2002-2013; OI van Diedenhoven, Bastiaan/0000-0001-5622-8619 NR 47 TC 0 Z9 0 U1 0 U2 0 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 AUG 15 PY 2008 VL 113 IS D15 AR D15311 DI 10.1029/2008JD009850 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 338MA UT WOS:000258510800007 ER PT J AU Zhong, Y Hu, W Eldridge, JI Chen, H Song, J Gottstein, G AF Zhong, Y. Hu, W. Eldridge, J. I. Chen, H. Song, J. Gottstein, G. TI Fiber push-out tests on Al2O3 fiber-reinforced NiAl-composites with and without hBN-interlayer at room and elevated temperatures SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE Al2O3 fiber; composites; interfacial shear strength; push-out test ID INTERFACIAL SHEAR-STRENGTH; MATRIX COMPOSITES; MECHANICAL-PROPERTIES; FRACTURE ENERGY; STRESS STATE; SAPPHIRE; BEHAVIOR; METAL; ROUGHNESS; FAILURE AB Fiber push-out tests were performed on continuous Al2O3 fiber-reinforced NiAl-composites with and without hBN-interlayer at room temperature (RT) and elevated temperature (900 degrees C). The average interfacial shear stress was 248 +/- 142 MPa and 72 +/- 28 MPa for NiAl/Al2O3 and NiAl/BN/Al2O3 composites at room temperature, respectively. At 900 degrees C, the push-out tests were aborted for NiAl/Al2O3 composites because of fiber fracture and cracking owing to mechanical twinning on rhombohedral {10 (1) over bar2} planes in single crystalline Al2O3 fibers, whereas the average interfacial shear stress was 13 +/- 7 MPa for NiAl/BN/Al2O3 composites. The debonding position along the interface as well as the initiation of debondig, on the top surface of NiAl/Al2O3 and NiAl/BN/Al2O3 composites were determined and discussed. Frictional coefficients of 0.29 and 0.11 for fiber sliding after interface debonding were obtained for NiAl/Al2O3 and NiAl/BN/Al2O3 composites at room temperature, respectively. (C) 2007 Elsevier B.V. All rights reserved. C1 [Zhong, Y.; Hu, W.; Chen, H.; Song, J.; Gottstein, G.] Rhein Westfal TH Aachen, Inst Phys Met & Met Phys, D-52056 Aachen, Germany. [Eldridge, J. I.] NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Zhong, Y (reprint author), Rhein Westfal TH Aachen, Inst Phys Met & Met Phys, Kopernikusstr 14, D-52056 Aachen, Germany. EM yzhong@imm.rwth-aachen.de FU Deutsche Forschungsgerneinschaft FX The authors acknowledge the financial support of the Deutsche Forschungsgerneinschaft through the collaborative research center SFB 561: "Thermally Highly Loaded Porous and cooled Multi-layer Systems for Combined Cycle Power Plants". The authors thank Mr. D. Hajas of Materials Chemistry of RWTH Aachen University, for fiber coating and Mr. T. Burlet of IMM, for the technical support with the fiber push-out tests. NR 39 TC 4 Z9 6 U1 2 U2 13 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD AUG 15 PY 2008 VL 488 IS 1-2 BP 372 EP 380 DI 10.1016/j.msea.2007.11.040 PG 9 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 343NH UT WOS:000258860300045 ER PT J AU Angelopoulos, V McFadden, JP Larson, D Carlson, CW Mende, SB Frey, H Phan, T Sibeck, DG Glassmeier, KH Auster, U Donovan, E Mann, IR Rae, IJ Russell, CT Runov, A Zhou, XZ Kepko, L AF Angelopoulos, Vassilis McFadden, James P. Larson, Davin Carlson, Charles W. Mende, Stephen B. Frey, Harald Phan, Tai Sibeck, David G. Glassmeier, Karl-Heinz Auster, Uli Donovan, Eric Mann, Ian R. Rae, I. Jonathan Russell, Christopher T. Runov, Andrei Zhou, Xu-Zhi Kepko, Larry TI Tail reconnection triggering substorm onset SO SCIENCE LA English DT Article ID MAGNETOSPHERIC SUBSTORMS; MAGNETIC RECONNECTION; GEOTAIL OBSERVATIONS; CURRENT SHEET; MAGNETOTAIL; CLUSTER; GROWTH; PHASE AB Magnetospheric substorms explosively release solar wind energy previously stored in Earth's magnetotail, encompassing the entire magnetosphere and producing spectacular auroral displays. It has been unclear whether a substorm is triggered by a disruption of the electrical current flowing across the near- Earth magnetotail, at similar to 10 R(E) ( R(E): Earth radius, or 6374 kilometers), or by the process of magnetic reconnection typically seen farther out in the magnetotail, at similar to 20 to 30 R(E). We report on simultaneous measurements in the magnetotail at multiple distances, at the time of substorm onset. Reconnection was observed at 20 R(E), at least 1.5 minutes before auroral intensification, at least 2 minutes before substorm expansion, and about 3 minutes before near- Earth current disruption. These results demonstrate that substorms are likely initiated by tail reconnection. C1 [Angelopoulos, Vassilis; Russell, Christopher T.; Runov, Andrei; Zhou, Xu-Zhi] Univ Calif Los Angeles, Inst Geophys & Planetary Phys, ESS, Los Angeles, CA 90095 USA. [McFadden, James P.; Larson, Davin; Carlson, Charles W.; Mende, Stephen B.; Frey, Harald; Phan, Tai] Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. [Sibeck, David G.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Glassmeier, Karl-Heinz; Auster, Uli] TUBS, D-38106 Braunschweig, Germany. [Donovan, Eric] Univ Calgary, Dept Phys & Astron, Calgary, AB T2N 1N4, Canada. [Mann, Ian R.; Rae, I. Jonathan] Univ Alberta, Dept Phys, Edmonton, AB T6G 2M7, Canada. [Kepko, Larry] Univ New Hampshire, Ctr Space Sci, Durham, NH 03824 USA. RP Angelopoulos, V (reprint author), Univ Calif Los Angeles, Inst Geophys & Planetary Phys, ESS, Los Angeles, CA 90095 USA. EM vassilis@ucla.edu RI Zhou, Xuzhi/D-1831-2011; Sibeck, David/D-4424-2012; Kepko, Larry/D-7747-2012; Rae, Jonathan/D-8132-2013; OI Zhou, Xuzhi/0000-0003-4953-1761; Kepko, Larry/0000-0002-4911-8208; Frey, Harald/0000-0001-8955-3282; Donovan, Eric/0000-0002-8557-4155; Russell, Christopher/0000-0003-1639-8298 NR 34 TC 262 Z9 266 U1 6 U2 39 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 AUG 15 PY 2008 VL 321 IS 5891 BP 931 EP 935 DI 10.1126/science.1160495 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 337LD UT WOS:000258436700030 PM 18653845 ER PT J AU Koren, I Martins, JV Remer, LA Afargan, H AF Koren, Ilan Martins, J. Vanderlei Remer, Lorraine A. Afargan, Hila TI Smoke invigoration versus inhibition of clouds over the Amazon SO SCIENCE LA English DT Article ID POLLUTION AEROSOL; MODIS; MICROPHYSICS; ALBEDO; IMPACT; RAIN; AIR AB The effect of anthropogenic aerosols on clouds is one of the most important and least understood aspects of human- induced climate change. Small changes in the amount of cloud coverage can produce a climate forcing equivalent in magnitude and opposite in sign to that caused by anthropogenic greenhouse gases, and changes in cloud height can shift the effect of clouds from cooling to warming. Focusing on the Amazon, we show a smooth transition between two opposing effects of aerosols on clouds: the microphysical and the radiative. We show how a feedback between the optical properties of aerosols and the cloud fraction can modify the aerosol forcing, changing the total radiative energy and redistributing it over the atmospheric column. C1 [Koren, Ilan; Afargan, Hila] Weizmann Inst Sci, Dept Environm Sci, IL-76100 Rehovot, Israel. [Martins, J. Vanderlei] Univ Maryland Baltimore Cty, Dept Phys, Baltimore, MD 21250 USA. [Martins, J. Vanderlei] Univ Maryland Baltimore Cty, Joint Ctr Earth Syst Technol, Baltimore, MD 21250 USA. [Martins, J. Vanderlei; Remer, Lorraine A.] NASA, Atmospheres Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Koren, I (reprint author), Weizmann Inst Sci, Dept Environm Sci, IL-76100 Rehovot, Israel. RI Koren, Ilan/K-1417-2012 OI Koren, Ilan/0000-0001-6759-6265 NR 24 TC 178 Z9 183 U1 4 U2 34 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 AUG 15 PY 2008 VL 321 IS 5891 BP 946 EP 949 DI 10.1126/science.1159185 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 337LD UT WOS:000258436700034 PM 18703738 ER PT J AU Crow, WT Reichle, RH AF Crow, W. T. Reichle, R. H. TI Comparison of adaptive filtering techniques for land surface data assimilation SO WATER RESOURCES RESEARCH LA English DT Article ID ENSEMBLE KALMAN FILTER; ZONE SOIL-MOISTURE; ERROR STATISTICS; MODEL; TEMPERATURE; IMPACT AB The accurate specification of modeling and observational error information required by data assimilation algorithms is a major obstacle to the successful application of a land surface data assimilation system. The source and statistical structure of these errors are often unknown, and poor assumptions concerning the relative magnitude of modeling and observation uncertainty degrade the quality of land data assimilation products. In theory, adaptive filtering approaches are capable of estimating model and observation error covariance information during the online cycling of a data assimilation system. To date, however, these approaches have not been widely applied to land surface models. Here, we implement and compare four separate adaptive filtering schemes in a data assimilation system designed to ingest remotely sensed surface soil moisture retrievals. Upon testing of each scheme via a synthetic twin data assimilation experiment, three of the four adaptive approaches are found to provide substantially improved soil moisture estimates. However, the specific model and observation characteristics of satellite-based surface soil moisture retrievals contribute to the relatively slow convergence of all schemes. Overall, results highlight the need to consider unique aspects of the land data assimilation problem when designing and/or evaluating the relative performance of adaptive filtering algorithms. C1 [Crow, W. T.] USDA ARS, Hydrol & Remote Sensing Lab, Beltsville, MD 20705 USA. [Reichle, R. H.] NASA, Goddard Space Flight Ctr, Goddard Earth Sci & Technol Ctr, Global Modeling & Assimilat Off, Greenbelt, MD 20771 USA. RP Crow, WT (reprint author), USDA ARS, Hydrol & Remote Sensing Lab, Room 104,Bldg 007,BARC W, Beltsville, MD 20705 USA. EM wade.crow@ars.usda.gov RI Reichle, Rolf/E-1419-2012 FU NASA [NNG05GB61G] FX Partial support for this study was provided through NASA grant NNG05GB61G. NR 28 TC 28 Z9 28 U1 1 U2 4 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 AUG 15 PY 2008 VL 44 IS 8 AR W08423 DI 10.1029/2008WR006883 PG 12 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA 338OI UT WOS:000258516900001 ER PT J AU Lyatsky, W Khazanov, GV AF Lyatsky, Wladislaw Khazanov, George V. TI A predictive model for relativistic electrons at geostationary orbit SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SPACE WEATHER AB We developed a predictive model for forecasting relativistic electrons at geostationary orbit that provides very high correlation between the predicted and actual electron fluxes. We integrated numerically the two linked continuity equations for preliminary accelerated electrons and relativistic electrons. The model includes sources and losses, and it uses solar wind data as only input parameters. We used the solar wind coupling function as the source, while the loss term we assumed to be proportional to the solar wind density which plays an important role in the decay of relativistic electrons. Relativistic electron fluxes, predicted from this model, show very high correlation with the actual electron fluxes at geostationary orbit. We tested the model for four-year period (2004-2007). The correlation coefficients between predicted and actual values of the electron fluxes for one day ahead for each year are about 0.93. C1 [Lyatsky, Wladislaw; Khazanov, George V.] NASA, George C Marshall Space Flight Ctr, NSSTC, Huntsville, AL 35805 USA. RP Lyatsky, W (reprint author), NASA, George C Marshall Space Flight Ctr, NSSTC, 320 Sparkman Dr, Huntsville, AL 35805 USA. EM lyatsky@cspar.uah.edu FU NASA FX We gratefully acknowledge invaluable efforts of the NOAA staff in providing data on relativistic electron fluxes from geostationary spacecraft, and the Goddard Space Flight Center in providing solar wind data. 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 by NASA HQ POLAR Project, and NASA LWS Program. Wladislaw Lyatsky is a fellow of Oak Ridge Associated Universities, Oak Ridge, Tennessee. NR 17 TC 4 Z9 4 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 AUG 14 PY 2008 VL 35 IS 15 AR L15108 DI 10.1029/2008GL034688 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 338LQ UT WOS:000258509700006 ER PT J AU Sun, DL Lau, KM Kafatos, M AF Sun, Donglian Lau, K. M. Kafatos, Menas TI Contrasting the 2007 and 2005 hurricane seasons: Evidence of possible impacts of Saharan dry air and dust on tropical cyclone activity in the Atlantic basin SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SURFACE-TEMPERATURE; NORTH-ATLANTIC; MINERAL DUST; TRADE WINDS; EL-NINO; INTENSITY; AEROSOLS; CLIMATE AB In this study, we provide preliminary evidence of possible modulation by Saharan dust of hurricane genesis and intensification, by contrasting the 2007 and 2005 hurricane seasons. It is found that dust aerosol loadings over the Atlantic Ocean are much higher in 2007 than in 2005. The temperature difference between 2007 and 2005 shows warming in the low-middle troposphere (900-700 hPa) in the dusty region in the eastern North Atlantic, and cooling in the Main Development Region (MDR). The humidity (wind) differences between 2007 and 2005 indicate significant drying (subsidence) in the Western North Atlantic (WNA) in 2007. The drier air in the WNA in 2007 is found to be associated with the further westward transport of the Saharan air layer (SAL). To quantify wind pattern favorable for transport of SAL over the WNA, we define a zonal wind stretch index which shows significant long-term correlation with the mid-level humidity in the WNA. Analyses of the stretch index and related environmental controls suggest that the westward expansion of the Saharan dry air and dust layer can be an important factor in contributing to the difference between the relatively quiescent hurricane season in 2007 and the very active season of 2005. C1 [Sun, Donglian; Kafatos, Menas] George Mason Univ, Coll Sci, Ctr Earth Observing & Space Res, Fairfax, VA 22030 USA. [Lau, K. M.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Sun, DL (reprint author), George Mason Univ, Coll Sci, Ctr Earth Observing & Space Res, Res Bldg,4400 Univ Dr, Fairfax, VA 22030 USA. EM dsun@gmu.edu RI Lau, William /E-1510-2012 OI Lau, William /0000-0002-3587-3691 FU NASA [NNX06AF30G]; NSF [NSF0543330] FX This work was supported by NASA grant NNX06AF30G and NSF grant NSF0543330. We appreciate the reviewers for their helpful comments to improve this manuscript. NR 34 TC 28 Z9 28 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 AUG 14 PY 2008 VL 35 IS 15 AR L15405 DI 10.1029/2008GL034529 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 338LQ UT WOS:000258509700005 ER PT J AU Divakarla, M Barnet, C Goldberg, M Maddy, E Irion, F Newchurch, M Liu, XP Wolf, W Flynn, L Labow, G Xiong, XZ Wei, J Zhou, LH AF Divakarla, Murty Barnet, Christopher Goldberg, Mitchell Maddy, Eric Irion, Fredrick Newchurch, Mike Liu, Xingpin Wolf, Walter Flynn, Lawrence Labow, Gordon Xiong, Xiaozhen Wei, Jennifer Zhou, Lihang TI Evaluation of Atmospheric Infrared Sounder ozone profiles and total ozone retrievals with matched ozonesonde measurements, ECMWF ozone data, and Ozone Monitoring Instrument retrievals SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID MODEL; AIRS/AMSU/HSB; PRODUCTS AB An evaluation of the Atmospheric Infrared Sounder (AIRS) version 4 (V4) and version 5 (V5) retrieved ozone profiles and the total column ozone is performed using collocated ozonesonde (O3SND) profiles and total ozone measurements from the World Ozone and Ultraviolet Radiation Data Center (WOUDC) archives. Using O(3)SNDs and Brewer/Dobson Network (BD) measurements as the truth, bias and root-mean-squared (RMS) difference statistics are computed for the AIRS ozone profile retrievals and the derived total ozone. In addition, global monthly maps of total ozone generated for the AIRS retrievals are compared with the Ozone Monitoring Instrument (OMI) and the Solar Backscatter Ultra Violet (SBUV/2) instrument derived maps to evaluate the characteristic trends and seasonal cycle depicted by the AIRS retrieval. The results of the validation exercise reveal that the AIRS V5 algorithm significantly improves the ozone profile retrieval biases and RMS differences for the lower troposphere and, especially, over the tropical region where the V4 algorithm shows larger discrepancies with the O3SND measurements. The V5 retrieval biases with global O3SNDs are less than 5% for both the stratosphere and the troposphere. The RMS differences are less than 20% for the upper stratosphere and are close to 20% for the lower stratosphere and the troposphere. Total ozone amounts from both the V4 and V5 versions agree well with the global BD station measurements with a bias of less than 4% and an RMS difference of approximately 8%. Analysis of V5 total ozone monthly maps reveals that the V5 ozone retrievals depict seasonal trends and patterns in concurrence with OMI and SBUV/2 observations. C1 [Divakarla, Murty] IM Syst Grp Inc, Rockville, MD 20852 USA. [Barnet, Christopher; Goldberg, Mitchell; Wolf, Walter; Flynn, Lawrence] NOAA, NESDIS, Ctr Satellite Applicat & Res, Camp Springs, MD 20746 USA. [Maddy, Eric; Liu, Xingpin; Xiong, Xiaozhen; Wei, Jennifer; Zhou, Lihang] QSS Grp Inc, Lanham, MD 20706 USA. [Irion, Fredrick] NASA, Jet Prop Lab, Pasadena, CA 91109 USA. [Newchurch, Mike] Univ Alabama, Dept Atmospher Sci, Huntsville, AL 35805 USA. [Labow, Gordon] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Divakarla, M (reprint author), IM Syst Grp Inc, 6309 Execut Blvd, Rockville, MD 20852 USA. EM murty.divakarla@noaa.gov; chris.barnet@noaa.gov; mitch.goldberg@noaa.gov; eric.maddy@noaa.gov; bill.irion@jpl.nasa.gov; mike@nsstc.uah.edu; xingpin.liu@noaa.gov; walter.wolf@noaa.gov; lawrence.e.flynn@noaa.gov; labow@lglass.gsfc.nasa.gov; xiaozhen.xiong@noaa.gov; jennifer.wei@noaa.gov; lihang.zhou@noaa.gov RI Flynn, Lawrence/B-6321-2009; Maddy, Eric/G-3683-2010; Goldberg, Mitch/F-5589-2010; Barnet, Christopher/F-5573-2010; Divakarla, Murty/E-7936-2011; Wolf, Walter/E-7935-2011; Zhou, Lihang/E-7938-2011; Xiong, Xiaozhen/F-6591-2010 OI Flynn, Lawrence/0000-0001-6856-2614; Maddy, Eric/0000-0003-1151-339X; Divakarla, Murty/0000-0002-0399-3381; Wolf, Walter/0000-0002-2102-8833; Zhou, Lihang/0000-0001-6232-2871; NR 23 TC 19 Z9 19 U1 2 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 AUG 13 PY 2008 VL 113 IS D15 AR D15308 DI 10.1029/2007JD009317 PG 24 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 338LY UT WOS:000258510600001 ER PT J AU Plemmons, DH Mehta, M Clark, BC Kounaves, SP Peach, LL Renno, NO Tamppari, L Young, SMM AF Plemmons, D. H. Mehta, M. Clark, B. C. Kounaves, S. P. Peach, L. L., Jr. Renno, N. O. Tamppari, L. Young, S. M. M. TI Effects of the Phoenix Lander descent thruster plume on the Martian surface SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID LIQUEFACTION; IMPINGEMENT; JETS AB The exhaust plume of Phoenix's hydrazine monopropellant pulsed descent thrusters will impact the surface of Mars during its descent and landing phase in the northern polar region. Experimental and computational studies have been performed to characterize the chemical compounds in the thruster exhausts. No undecomposed hydrazine is observed above the instrument detection limit of 0.2%. Forty-five percent ammonia is measured in the exhaust at steady state. Water vapor is observed at a level of 0.25%, consistent with fuel purity analysis results. Moreover, the dynamic interactions of the thruster plumes with the ground have been studied. Large pressure overshoots are produced at the ground during the ramp-up and ramp-down phases of the duty cycle of Phoenix's pulsed engines. These pressure overshoots are superimposed on the 10 Hz quasi-steady ground pressure perturbations with amplitude of about 5 kPa (at touchdown altitude) and have a maximum amplitude of about 20 -40 kPa. A theoretical explanation for the physics that causes these pressure perturbations is briefly described in this article. The potential for soil erosion and uplifting at the landing site is also discussed. The objectives of the research described in this article are to provide empirical and theoretical data for the Phoenix Science Team to mitigate any potential problem. The data will also be used to ensure proper interpretation of the results from on-board scientific instrumentation when Martian soil samples are analyzed. C1 [Plemmons, D. H.] Aerosp Testing Alliance, Arnold AFB, TN 37389 USA. [Mehta, M.; Renno, N. O.] Univ Michigan, Dept Atmospher Ocean & Space Sci, Ann Arbor, MI 48109 USA. [Clark, B. C.] Lockheed Martin Corp, Littleton, CO 80127 USA. [Kounaves, S. P.; Young, S. M. M.] Tufts Univ, Dept Chem, Medford, MA 02155 USA. [Peach, L. L., Jr.] Univ Space Res Assoc, Columbia, MD USA. [Tamppari, L.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Plemmons, DH (reprint author), Aerosp Testing Alliance, 1099 Schriever Ave, Arnold AFB, TN 37389 USA. EM david.plemmons@arnold.af.mil OI Kounaves, Samuel/0000-0002-2629-4831 FU NASA Jet Propulsion Laboratory; Phoenix Mars Mission FX This work was supported by NASA Jet Propulsion Laboratory and the Phoenix Mars Mission. In particular, we would like to thank Peter Smith (Phoenix Mission PI) of University of Arizona; Robert Shotwell (Project Systems Engineer), Rob Grover (EDL Systems Lead) and Mike Hecht (MECA Lead) of NASA JPL; Bill Boynton (TEGA Lead) of University of Arizona; Greg McAllister, Tim Fisher, Pete Huseman, Doug Gulick, and Tim Priser of Lockheed Martin Space Systems; Matt Dawson of Aerojet, Inc.; Chuck Davis of KSC; John Marshall of SETI; Ron Greeley of Arizona State University; Ray Arvidson of Washington University; and Jasper Kok and Robb Gillespie of the University of Michigan for all their support and guidance. NR 30 TC 7 Z9 7 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 AUG 13 PY 2008 VL 113 AR E003059 DI 10.1029/2007JE003059 PG 12 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 338NG UT WOS:000258514000001 ER PT J AU Funk, C Dettinger, MD Michaelsen, JC Verdin, JP Brown, ME Barlow, M Hoell, A AF Funk, Chris Dettinger, Michael D. Michaelsen, Joel C. Verdin, James P. Brown, Molly E. Barlow, Mathew Hoell, Andrew TI Warming of the Indian Ocean threatens eastern and southern African food security but could be mitigated by agricultural development SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article DE climate change; drought; famine; precipitation ID CLIMATE-CHANGE; SUSTAINABILITY SCIENCE; 20TH-CENTURY; RAINFALL; MODEL; ADAPTATION; MANAGEMENT; DROUGHT; PROJECT; SYSTEM AB Since 1980, the number of undernourished people in eastern and southern Africa has more than doubled. Rural development stalled and rural poverty expanded during the 1990s. Population growth remains very high, and declining per-capita agricultural capacity retards progress toward Millennium Development goals. Analyses of in situ station data and satellite observations of precipitation have identified another problematic trend: main growing-season rainfall receipts have diminished by approximate to 15% in food-insecure countries clustered along the western rim of the Indian Ocean. Occurring during the main growing seasons in poor countries dependent on rain-fed agriculture, these declines are societally dangerous. Will they persist or intensify? Tracing moisture deficits upstream to an anthropogenically warming Indian Ocean leads us to conclude that further rainfall declines are likely. We present analyses suggesting that warming in the central Indian Ocean disrupts onshore moisture transports, reducing continental rainfall. Thus, late 20th-century anthropogenic Indian Ocean warming has probably already produced societally dangerous climate change by creating drought and social disruption in some of the world's most fragile food economies. We quantify the potential impacts of the observed precipitation and agricultural capacity trends by modeling "millions of undernourished people" as a function of rainfall, population, cultivated area, seed, and fertilizer use. Persistence of current tendencies may result in a 50% increase in undernourished people by 2030. On the other hand, modest increases in per-capita agricultural productivity could more than offset the observed precipitation declines. Investing in agricultural development can help mitigate climate change while decreasing rural poverty and vulnerability. C1 [Funk, Chris] Univ Calif Santa Barbara, Dept Geog, Climate Hazard Grp, US Geol Survey, Santa Barbara, CA 93106 USA. [Dettinger, Michael D.] Univ Calif San Diego, Scripps Inst Oceanog, US Geol Survey, La Jolla, CA 92093 USA. [Brown, Molly E.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Barlow, Mathew; Hoell, Andrew] Univ Massachusetts, Lowell, MA 01854 USA. RP Funk, C (reprint author), Univ Calif Santa Barbara, Dept Geog, Climate Hazard Grp, US Geol Survey, 1629 Ellison Hall, Santa Barbara, CA 93106 USA. EM chris@geog.ucsb.edu 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 U.S. Agency for International Development Famine Early Warning System Network [04HQAG0001]; National Aeronautics and Space Administration [NNX07AG26G, NNG07HW21G]; National Science Foundation [ATM 0603555, ATM 0621237]; Office of Science, U.S. Department of Energy FX This research was supported by the U.S. Agency for International Development Famine Early Warning System Network under U.S. Geological Survey Cooperative Agreement 04HQAG0001, the National Aeronautics and Space Administration under Precipitation Science Grant NNX07AG26G, National Aeronautics and Space Administration decision support grant NNG07HW21G, and by the National Science Foundation under Grants ATM 0603555 and ATM 0621237. We thank these agencies for their support. We also thank and acknowledge the CMIP3 modeling groups for providing data for analysis; the Program for Climate Model Diagnosis and Intercomparison for collecting and archiving the model output; and the Johnson Space Center Climate Variability and Predictability Working Group on Coupled Modeling for organizing the model data-analysis activity. The multimodel data archive is supported by the Office of Science, U.S. Department of Energy. We would like to sincerely thank Stephen Schneider and the paper reviewers for their efforts. NR 45 TC 134 Z9 137 U1 11 U2 53 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD AUG 12 PY 2008 VL 105 IS 32 BP 11081 EP 11086 DI 10.1073/pnas.0708196105 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 339EK UT WOS:000258560700012 PM 18685101 ER PT J AU Yeh, C Shimabukuro, F Siegel, PH AF Yeh, C. Shimabukuro, F. Siegel, P. H. TI Reply to Comment on "Low-loss terahertz ribbon waveguides" SO APPLIED OPTICS LA English DT Article AB The confusion apparently stems from the fact that Our Paper [Appl. Opt. 44, 5937 (2005)] dealt with modulated pulses, modulated at terahertz frequency, while Mendis' paper [Appl. Opt. 47, 4231 (2008)] dealt with narrow-basehand Pulses that may contain a very large (terahertz) spectral width. Therefore, the criticism given by Mendis is erroneous, since his analysis is for baseband pulses only. (C) 2008 Optical Society of America. C1 [Yeh, C.; Shimabukuro, F.] Calif Adv Studies, Santa Monica, CA 90403 USA. [Siegel, P. H.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Yeh, C (reprint author), Calif Adv Studies, 826 5th St,Suite 3, Santa Monica, CA 90403 USA. EM evepanda@aol.com NR 3 TC 0 Z9 0 U1 1 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 AUG 10 PY 2008 VL 47 IS 23 BP 4253 EP 4254 DI 10.1364/AO.47.004253 PG 2 WC Optics SC Optics GA 342KZ UT WOS:000258784300010 ER PT J AU Gorti, U Hollenbach, D AF Gorti, U. Hollenbach, D. TI Line emission from gas in optically thick dust disks around young stars SO ASTROPHYSICAL JOURNAL LA English DT Review DE infrared : ISM; line : formation; planetary systems : protoplanetary disks; radiative transfer ID T-TAURI STARS; HERBIG AE/BE STARS; MAIN-SEQUENCE STARS; IRRADIATED PROTOPLANETARY DISKS; MOLECULAR-HYDROGEN EMISSION; PASSIVE CIRCUMSTELLAR DISKS; SPITZER-IRS SPECTRA; X-RAY-EMISSION; PHOTODISSOCIATION REGIONS; INTERSTELLAR-MEDIUM AB We present self-consistent models of gas in optically thick dusty disks and calculate its thermal, density, and chemical structure. The models focus on an accurate treatment of the upper layers where line emission originates and at radii k0.7 AU. Although our models are applicable to stars of any mass, we present here only results around 1 M stars where we have varied dust properties, X- ray luminosities, and UV luminosities. We separately treat gas and dust thermal balance and calculate line luminosities at infrared and submillimeter wavelengths from all transitions originating in the predominantly neutral gas that lies below the very tenuous and completely ionized surface of the disk. We find that the [ Ar ii] 7 m, [ Ne ii] 12.8 m, [ Fe i] 24 m, [ S i] 25 m, [ Fe ii] 26 m, [ Si ii] 35 m, [ O i] 63 m, and pure rotational lines of H2 and CO can be quite strong and are good indicators of the presence and distribution of gas in disks. Water is an important coolant in the disk, and many water emission lines can be moderately strong. Current and future observational facilities such as the Spitzer Space Telescope, Herschel Space Observatory, and SOFIA are capable of detecting gas emission from young disks. We apply our models to the disk around the nearby young star, TW Hya, and find good agreement between our model calculations and observations. We also predict strong emission lines from the TW Hya disk that are likely to be detected by future facilities. We suggest that the gas disk around TW Hya may be truncated to 120 AU, compared to its dust disk of 174 AU. We speculate that photoevaporation due to the strong stellar FUV field from TW Hya is responsible for the gas disk truncation. C1 [Gorti, U.] Univ Calif Berkeley, Berkeley, CA 94720 USA. [Gorti, U.; Hollenbach, D.] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Gorti, U (reprint author), Univ Calif Berkeley, Berkeley, CA 94720 USA. NR 109 TC 90 Z9 90 U1 0 U2 6 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 AUG 10 PY 2008 VL 683 IS 1 BP 287 EP 303 DI 10.1086/589616 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 335NA UT WOS:000258296100025 ER PT J AU Fragos, T Kalogera, V Belczynski, K Fabbiano, G Kim, DW Brassington, NJ Angelini, L Davies, RL Gallagher, JS King, AR Pellegrini, S Trinchieri, G Zepf, SE Kundu, A Zezas, A AF Fragos, T. Kalogera, V. Belczynski, K. Fabbiano, G. Kim, D. -W. Brassington, N. J. Angelini, L. Davies, R. L. Gallagher, J. S. King, A. R. Pellegrini, S. Trinchieri, G. Zepf, S. E. Kundu, A. Zezas, A. TI Models for low-mass X-ray binaries in the elliptical galaxies NGC 3379 and NGC 4278: Comparison with observations SO ASTROPHYSICAL JOURNAL LA English DT Article DE binaries : close; galaxies : elliptical and lenticular, cD; stars : evolution; X-rays : binaries ID COMMON ENVELOPE EVOLUTION; MILLISECOND RADIO PULSARS; GLOBULAR-CLUSTERS; MAGNETIC BRAKING; BLACK-HOLES; LUMINOSITY FUNCTION; SPECTRAL PROPERTIES; STELLAR EVOLUTION; EMISSION; CHANDRA AB We present theoretical models for the formation and evolution of populations of low-mass X-ray binaries (LMXBs) in the two elliptical galaxies NGC 3379 and NGC 4278. The models are calculated with the recently updated StarTrack code, assuming only a primordial galactic field LMXB population. StarTrack is an advanced population synthesis code that has been tested and calibrated using detailed binary star calculations and incorporates all the important physical processes of binary evolution. The simulations are targeted to modeling and understanding the origin of the X-ray luminosity functions (XLFs) of point sources in these galaxies. For the first time we explore the population XLF in luminosities below 10(37) ergs s (1), as probed by the most recent observational results. We consider models for the formation and evolution of LMXBs in galactic fields with different CE efficiencies, stellar wind prescriptions, magnetic braking laws, and IMFs. We identify models that produce XLFs consistent with the observations both in shape and absolute normalization, suggesting that a primordial galactic field LMXB population can make a significant contribution to the total population of an elliptical galaxy. We also find that the treatment of the outburst luminosity of transient systems remains a crucial factor for the determination of the XLF, since the modeled populations are dominated by transient X-ray systems. C1 [Fragos, T.; Kalogera, V.] Northwestern Univ, Dept Phys & Astron, Evanston, IL 60208 USA. [Belczynski, K.] New Mexico State Univ, Dept Astron, Las Cruces, NM 88003 USA. [Fabbiano, G.; Kim, D. -W.; Brassington, N. J.; Zezas, A.] Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. [Angelini, L.] NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. [Davies, R. L.] Univ Oxford, Oxford OX1 3RH, England. [Gallagher, J. S.] Univ Wisconsin, Dept Astron, Madison, WI 53706 USA. [King, A. R.] Univ Leicester, Leicester LE1 7RH, Leics, England. [Pellegrini, S.] Univ Bologna, Dipartimento Astron, Bologna, Italy. [Trinchieri, G.] INAF Observ Astron Brera, I-20121 Milan, Italy. [Zepf, S. E.; Kundu, A.] Michigan State Univ, Dept Phys & Astron, E Lansing, MI 48824 USA. RP Fragos, T (reprint author), Northwestern Univ, Dept Phys & Astron, 2145 Sheridan Rd, Evanston, IL 60208 USA. EM tassosfragos@northwestern.edu; vicky@northwestern.edu; kbelczyn@nmsu.edu; gfabbiano@cfa.harvard.edu; kim@cfa.harvard.edu; nbrassington@head.cfa.harvard.edu; angelini@davide.gsfc.nasa.gov; rld@astro.ox.ac.uk; jsg@astro.wisc.edu; ark@star.le.ac.uk; silvia.pellegrini@unibo.it; ginevra.trinchieri@brera.inaf.it; zepf@pa.msu.edu; azezas@cfa.harvard.edu RI Zezas, Andreas/C-7543-2011 OI Zezas, Andreas/0000-0001-8952-676X NR 62 TC 42 Z9 42 U1 1 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 AUG 10 PY 2008 VL 683 IS 1 BP 346 EP 356 DI 10.1086/588456 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 335NA UT WOS:000258296100029 ER PT J AU Bouwman, J Henning, T Hillenbrand, LA Meyer, MR Pascucci, I Carpenter, J Hines, D Kim, JS Silverstone, MD Hollenbach, D Wolf, S AF Bouwman, J. Henning, Th. Hillenbrand, L. A. Meyer, M. R. Pascucci, I. Carpenter, J. Hines, D. Kim, J. S. Silverstone, M. D. Hollenbach, D. Wolf, S. TI The formation and evolution of planetary systems : Grain growth and chemical processing of dust in T Tauri systems SO ASTROPHYSICAL JOURNAL LA English DT Review DE circumstellar matter; planetary systems; stars : pre-main-sequence ID HERBIG-AE/BE STARS; INTERSTELLAR SILICATE MINERALOGY; SCORPIUS OB ASSOCIATION; SPITZER-SPACE-TELESCOPE; YOUNG STELLAR OBJECTS; MAIN-SEQUENCE STARS; X-RAY SOURCES; PROTOPLANETARY ACCRETION DISKS; SPECTRAL ENERGY-DISTRIBUTIONS; INFRARED SPECTROGRAPH SPECTRA AB This paper is one in a series presenting results obtained within the Formation and Evolution of Planetary Systems (FEPS) Legacy Science Program on the Spitzer Space Telescope. Here we present a study of dust processing and growth in seven protoplanetary disks. Our spectra indicate that the circumstellar silicate dust grains have grown to sizes at least 10 times larger than observed in the interstellar medium and show evidence for a non-negligible (similar to 5% in mass fractions) contribution from crystalline species. These results are similar to those of other studies of protoplanetary disks. In addition, we find a correlation between the strength of the amorphous silicate feature and the shape of the spectral energy distribution. This latter result is consistent with the growth and subsequent gravitational settling of dust grains toward the disk midplane. Furthermore, we find a change in the relative abundance of the different crystalline species: more enstatite than forsterite is observed in the inner warm dust population at similar to 1 AU, while forsterite dominates in the colder outer regions at similar to 5-15 AU. This change in the relative abundances argues for a localized crystallization process rather than a radial mixing scenario in which crystalline silicates are being transported outwards from a single formation region in the hot inner parts of the disk. Finally, we report the detection of emission from polycyclic aromatic hydrocarbon ( PAH) molecules in five out of seven sources. We find a tentative PAH band at 8.2 mu m that was previously undetected in the spectra of disks around low-mass pre-main-sequence stars. C1 [Bouwman, J.; Henning, Th.; Wolf, S.] Max Planck Inst Astron, D-69117 Heidelberg, Germany. [Hillenbrand, L. A.; Carpenter, J.] CALTECH, Dept Astron, Pasadena, CA 91125 USA. [Meyer, M. R.; Pascucci, I.; Kim, J. S.; Silverstone, M. D.] Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. [Hines, D.] Space Sci Inst, Boulder, CO 80301 USA. [Hollenbach, D.] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Bouwman, J (reprint author), Max Planck Inst Astron, Konigstuhl 17, D-69117 Heidelberg, Germany. NR 116 TC 112 Z9 113 U1 0 U2 6 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 AUG 10 PY 2008 VL 683 IS 1 BP 479 EP 498 DI 10.1086/587793 PG 20 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 335NA UT WOS:000258296100041 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 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 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 Santostasi, G 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. 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. de la Jordana, L. Sancho 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. 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. Santostasi, G. CA LIGO Sci Collaboration TI Beating the spin-down limit on gravitational wave emission from the Crab pulsar SO ASTROPHYSICAL JOURNAL LETTERS LA English DT Article DE gravitational waves; pulsars : individual (Crab pulsar) ID WIND TORI; RADIATION; NEUTRON; STARS AB We present direct upper limits on gravitational wave emission from the Crab pulsar using data from the first 9 months of the fifth science run of the Laser Interferometer Gravitational-wave Observatory (LIGO). These limits are based on two searches. In the first we assume that the gravitational wave emission follows the observed radio timing, giving an upper limit on gravitational wave emission that beats indirect limits inferred from the spin-down and braking index of the pulsar and the energetics of the nebula. In the second we allow for a small mismatch between the gravitational and radio signal frequencies and interpret our results in the context of two possible gravitational wave emission mechanisms. C1 McNeese State Univ, Lake Charles, LA 70609 USA. Max Planck Inst Gravitat Phys, Albert Einstein Inst, D-14476 Golm, Germany. Max Planck Inst Gravitat Phys, Albert Einstein Inst, D-30167 Hannover, Germany. Andrews Univ, Berrien Springs, MI 49104 USA. Australian Natl Univ, Canberra, ACT 0200, Australia. CALTECH, Pasadena, CA 91125 USA. CALTECH, CaRT, Pasadena, CA 91125 USA. Cardiff Univ, Cardiff CF24 3AA, S Glam, Wales. Carleton Coll, Northfield, MN 55057 USA. Charles Sturt Univ, Wagga Wagga, NSW 2678, Australia. Columbia Univ, New York, NY 10027 USA. Embry Riddle Aeronaut Univ, Prescott, AZ 86301 USA. Hobart & William Smith Coll, Geneva, NY 14456 USA. Russian Acad Sci, Inst Appl Phys, Nizhnii Novgorod 603950, Russia. Interuniv Ctr Astron & Astrophys, Pune 411007, Maharashtra, India. Leibniz Univ Hannover, D-30167 Hannover, Germany. CALTECH, LIGO, Pasadena, CA 91125 USA. MIT, LIGO, Cambridge, MA 02139 USA. Hanford Observ, LIGO, Richland, WA 99352 USA. Livingston Observ, LIGO, Livingston, LA 70754 USA. Louisiana State Univ, Baton Rouge, LA 70803 USA. Louisiana Tech Univ, Ruston, LA 71272 USA. Loyola Univ, New Orleans, LA 70118 USA. Moscow MV Lomonosov State Univ, Moscow 119992, Russia. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Natl Astron Observ Japan, Tokyo 1818588, Japan. Northwestern Univ, Evanston, IL 60208 USA. Rutherford Appleton Lab, Didcot OX11 0QX, Oxon, England. San Jose State Univ, San Jose, CA 95192 USA. Sonoma State Univ, Rohnert Pk, CA 94928 USA. SE Louisiana Univ, Hammond, LA 70402 USA. So Univ & A&M Coll, Baton Rouge, LA 70813 USA. Stanford Univ, Stanford, CA 94305 USA. Syracuse Univ, Syracuse, NY 13244 USA. Penn State Univ, University Pk, PA 16802 USA. Univ Texas Austin, Austin, TX 78712 USA. Univ Texas Brownsville & Texas Southmost Coll, Brownsville, TX 78520 USA. Trinity Univ, San Antonio, TX 78212 USA. Univ Illes Balears, E-07122 Palma de Mallorca, Spain. Univ Adelaide, Adelaide, SA 5005, Australia. Univ Birmingham, Birmingham B15 2TT, W Midlands, England. Univ Florida, Gainesville, FL 32611 USA. Univ Glasgow, Glasgow G12 8QQ, Lanark, Scotland. Univ Maryland, College Pk, MD 20742 USA. Univ Massachusetts, Amherst, MA 01003 USA. Univ Michigan, Ann Arbor, MI 48109 USA. Univ Minnesota, Minneapolis, MN 55455 USA. Univ Oregon, Eugene, OR 97403 USA. Univ Rochester, Rochester, NY 14627 USA. Univ Salerno, I-84084 Salerno, Italy. Univ Sannio, I-82100 Benevento, Italy. Univ Southampton, Southampton SO17 1BJ, Hants, England. Univ Strathclyde, Glasgow G1 1XQ, Lanark, Scotland. Univ Western Australia, Nedlands, WA 6009, Australia. Univ Wisconsin, Milwaukee, WI 53201 USA. Washington State Univ, Pullman, WA 99164 USA. RP Abbott, B (reprint author), McNeese State Univ, Lake Charles, LA 70609 USA. RI Lam, Ping Koy/A-5276-2008; McClelland, David/E-6765-2010; Martin, Iain/A-2445-2010; Hild, Stefan/A-3864-2010; Schutz, Bernard/B-1504-2010; 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; Freise, Andreas/F-8892-2011; Kawabe, Keita/G-9840-2011; Finn, Lee Samuel/A-3452-2009; 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; Biswas, Rahul/H-7474-2016; Sigg, Daniel/I-4308-2015; Pinto, Innocenzo/L-3520-2016; Harms, Jan/J-4359-2012; Frey, Raymond/E-2830-2016; Ward, Robert/I-8032-2014; 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; Vyatchanin, Sergey/J-2238-2012; Khazanov, Efim/B-6643-2014; Lucianetti, Antonio/G-7383-2014; Khalili, Farit/D-8113-2012 OI Lam, Ping Koy/0000-0002-4421-601X; McClelland, David/0000-0001-6210-5842; Strain, Kenneth/0000-0002-2066-5355; Lueck, Harald/0000-0001-9350-4846; Finn, Lee Samuel/0000-0002-3937-0688; Boschi, Valerio/0000-0001-8665-2293; 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; Principe, Maria/0000-0002-6327-0628; Vecchio, Alberto/0000-0002-6254-1617; Khan, Rubab/0000-0001-5100-5168; Postiglione, Fabio/0000-0003-0628-3796; Biswas, Rahul/0000-0002-0774-8906; Sigg, Daniel/0000-0003-4606-6526; Frey, Raymond/0000-0003-0341-2636; Ward, Robert/0000-0001-5503-5241; Whelan, John/0000-0001-5710-6576; Fairhurst, Stephen/0000-0001-8480-1961; Allen, Bruce/0000-0003-4285-6256; Zhao, Chunnong/0000-0001-5825-2401; Pitkin, Matthew/0000-0003-4548-526X; NR 30 TC 110 Z9 110 U1 2 U2 16 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 2041-8205 EI 2041-8213 J9 ASTROPHYS J LETT JI Astrophys. J. Lett. PD AUG 10 PY 2008 VL 683 IS 1 BP L45 EP L49 DI 10.1086/591526 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 340BO UT WOS:000258621300012 ER PT J AU Bohnhardt, H Mumma, MJ Villanueva, GL DiSanti, MA Bonev, BP Lippi, M Kaufl, HU AF Boehnhardt, H. Mumma, M. J. Villanueva, G. L. DiSanti, M. A. Bonev, B. P. Lippi, M. Kaeufl, H. U. TI The unusual volatile composition of the Halley-type comet 8P/Tuttle: Addressing the existence of an inner Oort Cloud SO ASTROPHYSICAL JOURNAL LETTERS LA English DT Article DE astrochemistry; comets : general; comets : individual (8P/Tuttle); infrared : solar system; molecular data; Oort Cloud ID PARENT VOLATILES; CARBON-MONOXIDE; DEEP IMPACT; FRAGMENT-C; FORMALDEHYDE; JUPITER; COMET-73P/SCHWASSMANN-WACHMANN-3; 153P/IKEYA-ZHANG; EVOLUTION; EMISSION AB We measured organic volatiles (CH4, CH3OH, C2H6, H2CO), CO, and water in comet 8P/Tuttle, a comet from the Oort Cloud reservoir now in a short-period Halley-type orbit. We compare its composition with two other comets in Halley-type orbits, and with comets of the "organics-normal" and "organics-depleted" classes. Chemical gradients are expected in the comet-forming region of the protoplanetary disk, and an individual comet should reflect its specific heritage. If Halley-type comets came from the inner Oort Cloud as proposed, we see no common characteristics that could distinguish such comets from those that were stored in the outer Oort Cloud. C1 [Mumma, M. J.; Villanueva, G. L.; DiSanti, M. A.; Bonev, B. P.] NASA, Goddard Space Flight Ctr, Solar Syst Explorat Div, Greenbelt, MD 20771 USA. [Boehnhardt, H.; Lippi, M.] Max Planck Inst Solar Syst Res, D-37191 Katlenburg Lindau, Germany. [Bonev, B. P.] Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA. [Kaeufl, H. U.] European So Observ, D-85748 Garching, Germany. RP Mumma, MJ (reprint author), NASA, Goddard Space Flight Ctr, Solar Syst Explorat Div, MS 690-3, Greenbelt, MD 20771 USA. EM michael.j.mumma@nasa.gov RI mumma, michael/I-2764-2013 FU German-Israeli Foundation for Scientific Research and Development [I-859-25.7/2005] FX We thank the VLT science operations team of the European Southern Observatory for efficient execution of the observations. This work was supported by the German-Israeli Foundation for Scientific Research and Development under grant I-859-25.7/2005, the International Max Planck Research School, and NASA's Planetary Astronomy Program, Astrobiology Program, and Postdoctoral Program. NR 42 TC 17 Z9 17 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA J9 ASTROPHYS J LETT JI Astrophys. J. Lett. PD AUG 10 PY 2008 VL 683 IS 1 BP L71 EP L74 DI 10.1086/591446 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 340BO UT WOS:000258621300018 ER PT J AU Thomson, BJ Bridges, NT Greeley, R AF Thomson, B. J. Bridges, N. T. Greeley, R. TI Rock abrasion features in the Columbia Hills, Mars SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID PATHFINDER LANDING SITE; GUSEV CRATER; SPIRIT ROVER; AEOLIAN PROCESSES; SAND DUNES; SPECTROMETER; SOILS; STORM AB Wind-abraded rocks (ventifacts) observed along the Mars Exploration Rover (MER) Spirit traverse in the Columbia Hills reveal evidence for complex wind flow patterns. Multiple superposed sets of eolian bed forms are evident in rover images and more broadly in High Resolution Imaging Science Experiment (HiRISE) image coverage. Formative wind directions inferred from ventifacts are more consistent with smaller, second-order (T-2) eolian ridges rather than larger, first-order (T-1) ridges. This suggests that the direction of recent highest-energy saltation may more commonly be aligned with the higher-order textures on bed form surfaces, perhaps because of bed form -modified (secondary) airflow around T-1 ridges. Additionally, the lack of ventifacts with formative wind directions consistent with T-1 ridges may indicate that either the ventifact textures consistent with T-1 ridge orientations have been overprinted by abrasion commensurate with T-2 ridges or, alternatively, the rocks were emplaced subsequent to the formation and stabilization of T-1 bed forms. In both cases, T-1 ridges appear fairly immobile and may provide less sand from winds blowing perpendicular to their ridge crests compared to winds consistent with T-2 orientation. C1 [Thomson, B. J.; Bridges, N. T.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Greeley, R.] Arizona State Univ, Sch Earth & Space Explorat, Tempe, AZ 85287 USA. RP Thomson, BJ (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM thomson@jpl.nasa.gov RI Bridges, Nathan/D-6341-2016; OI Thomson, Bradley/0000-0001-8635-8932 NR 57 TC 12 Z9 12 U1 0 U2 4 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 AUG 9 PY 2008 VL 113 IS E8 AR E08010 DI 10.1029/2007JE003018 PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 336CG UT WOS:000258341300002 ER PT J AU Pierrard, V Khazanov, GV Cabrera, J Lemaire, J AF Pierrard, V. Khazanov, G. V. Cabrera, J. Lemaire, J. TI Influence of the convection electric field models on predicted plasmapause positions during magnetic storms SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID RING CURRENT; MAGNETOSPHERIC CONVECTION; MOTION; PLASMASPHERE; DYNAMICS; SIMULATIONS; POTENTIALS; WAVES AB In the present work, we determine how three well documented models of the magnetospheric electric field, and two different mechanisms proposed for the formation of the plasmapause influence the radial distance, the shape and the evolution of the plasmapause during the geomagnetic storms of 28 October 2001 and of 17 April 2002. The convection electric field models considered are: McIlwain's E5D electric field model, Volland-Stern's model, and Weimer's statistical model compiled from low-Earth orbit satellite data. The mechanisms for the formation of the plasmapause to be tested are: (1) the MHD theory where the plasmapause should correspond to the last-closed-equipotential (LCE) or last-closed-streamline (LCS), if the E-field distribution is stationary or timedependent respectively; (2) the interchange mechanism where the plasmapause corresponds to streamlines tangent to a Zero-Parallel-Force surface where the field-aligned plasma distribution becomes convectively unstable during enhancements of the E-field intensity in the nightside local time sector. The results of the different time dependent simulations are compared with concomitant EUV/IMAGE observations when available. The plasmatails or plumes observed after both selected geomagnetic storms are predicted in all simulations and for all E-field models. However, their shapes are quite different depending on the E-field models and the mechanisms that are used. Despite the partial success of the simulations to reproduce plumes during magnetic storms and substorms, there remains a long way to go before the detailed structures observed in the EUV observations during periods of geomagnetic activity can be accounted for very precisely by the existing E-field models. Furthermore, it cannot be excluded that the mechanisms currently identified to explain the formation of "Carpenter's knee'' during substorm events, will have to be revised or complemented in the cases of geomagnetic storms. C1 [Pierrard, V.; Lemaire, J.] Belgian Inst Space Aeron, B-1180 Brussels, Belgium. [Cabrera, J.] Univ Catholique Louvain, Ctr Space Radiat, B-1348 Louvain, Belgium. [Khazanov, G. V.] NASA, George C Marshall Space Flight Ctr, Sci & Explorat Off, Natl Space Sci & Technol Ctr, Huntsville, AL 35805 USA. RP Pierrard, V (reprint author), Belgian Inst Space Aeron, 3 Ave Circulaire, B-1180 Brussels, Belgium. EM viviane.pierrard@oma.be RI Cabrera, Juan/C-2908-2008; OI Cabrera, Juan/0000-0003-1551-8665; Pierrard, Viviane/0000-0001-5014-7682 NR 43 TC 26 Z9 26 U1 1 U2 4 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 AUG 9 PY 2008 VL 113 IS A8 AR A08212 DI 10.1029/2007JA012612 PG 21 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 336CO UT WOS:000258342100001 ER PT J AU Landerer, FW Jungclaus, JH Marotzke, J AF Landerer, Felix W. Jungclaus, Johann H. Marotzke, Jochem TI El Nino-Southern Oscillation signals in sea level, surface mass redistribution, and degree-two geoid coefficients SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID CONTINENTAL WATER STORAGE; HYDROLOGICAL CYCLE; SEASONAL CYCLE; GLOBAL OCEAN; MODEL; SCALE; TEMPERATURES; VARIABILITY; GRACE; EARTH AB We use a coupled Earth system model to simulate and quantify the impact of the El Nino-Southern Oscillation (ENSO) on monthly to interannual variations of steric and eustatic global mean sea level (GMSL), surface mass loading, and on the corresponding degree-two geoid coefficients (C-21, S-21, and C-20). GMSL is dominated by eustatic variations on monthly to interannual timescales, but less than 10% of the eustatic variance is related to ENSO. In contrast, steric GMSL correlates linearly in phase with ENSO with an explained variance of nearly 46%. Together these results imply that total GMSL variations are only weakly correlated with ENSO. Despite this small correlation, we find a distinct ENSO pattern of sizable surface mass load anomalies. Over the continents, this pattern is similar to typical ENSO-related precipitation anomalies. Over the oceans, the pattern features a global, albeit weaker, response, with generally increased loading in the Arctic and Pacific oceans, and decreased loading in the Atlantic and Indian oceans. These surface loading anomalies lead to statistically significant ENSO-related variations in the S-21 and C-20 geoid coefficients, but not in C-21. In analyzing the individual subsystem contributions, we find that S-21 is influenced by both ocean mass redistribution and soil moisture loading, whereas C-20 is mainly influenced by soil moisture loading. Our results highlight the importance of high-amplitude regional loading anomalies that integrate to low-degree geoid anomalies. C1 [Landerer, Felix W.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Jungclaus, Johann H.; Marotzke, Jochem] Max Planck Inst Meteorol, D-20146 Hamburg, Germany. [Landerer, Felix W.] Int Max Planck Res Sch Earth Syst Modelling, Hamburg, Germany. RP Landerer, FW (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM felix.landerer@zmaw.de OI Landerer, Felix/0000-0003-2678-095X NR 52 TC 15 Z9 16 U1 0 U2 9 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 AUG 8 PY 2008 VL 113 IS C8 AR C08014 DI 10.1029/2008JC004767 PG 16 WC Oceanography SC Oceanography GA 336CB UT WOS:000258340800004 ER PT J AU Feldman, WC Bandfield, JL Diez, B Elphic, RC Maurice, S Nelli, SM AF Feldman, W. C. Bandfield, J. L. Diez, B. Elphic, R. C. Maurice, S. Nelli, S. M. TI North to south asymmetries in the water-equivalent hydrogen distribution at high latitudes on Mars SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID GROUND ICE; SUMMER TEMPERATURES; SPECTROMETER; PERMAFROST; STABILITY; DEPOSITS; ROCKS; VAPOR; SOILS; FROST AB Water content and burial depths derived from thermal and epithermal neutron currents measured by the Mars Odyssey Neutron Spectrometer are used to determine north to south asymmetries and intercorrelations at high latitudes on Mars. Our goal is to contrast observed asymmetries with predictions based on current climate conditions and potential regolith thermophysical and chemophysical properties. The average mass fraction of water-equivalent hydrogen within the buried layer is higher on average in the south between 60 degrees and 75 degrees latitude and is strongly anticorrelated with burial depth in both hemispheres. These results argue that the observed water content at high latitudes may require differing north to south thermophysical and/or chemophysical properties of the regolith. C1 [Feldman, W. C.] Planetary Sci Inst, Tucson, AZ 85719 USA. [Bandfield, J. L.] Univ Washington, Dept Earth & Space Sci, Seattle, WA 98115 USA. [Elphic, R. C.] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. [Nelli, S. M.] Univ Michigan, Ann Arbor, MI 48109 USA. [Diez, B.; Maurice, S.] Ctr Etud Spatiale Rayonnements, Toulouse, France. RP Feldman, WC (reprint author), Planetary Sci Inst, 1700 E Ft Lowell,Suite 106, Tucson, AZ 85719 USA. EM feldman@psi.edu NR 38 TC 12 Z9 12 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 AUG 8 PY 2008 VL 113 IS E8 AR E08006 DI 10.1029/2007JE003020 PG 8 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 336CF UT WOS:000258341200002 ER PT J AU Johnson, SS Mischna, MA Grove, TL Zuber, MT AF Johnson, Sarah Stewart Mischna, Michael A. Grove, Timothy L. Zuber, Maria T. TI Sulfur-induced greenhouse warming on early Mars SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID GENERAL-CIRCULATION MODELS; MARTIAN ATMOSPHERE; MERIDIANI-PLANUM; TERRA-MERIDIANI; THERMAL STRUCTURE; OXYGEN FUGACITY; ANCIENT OCEANS; CO2 GREENHOUSE; GUSEV CRATER; SURFACE AB Mineralogical, geological, geophysical, and isotopic data recently returned from Mars suggest that the delivery of sulfur gases to the atmosphere may have played a significant role in the planet's early evolution. Using the Gusev Crater basalt composition and a batch melting model, we obtain a high sulfur solubility, approximately 1400 ppm, in Martian mantle melts. We proceed to explore different scenarios for the pulsed degassing of sulfur volatiles associated with the emplacement of near-surface dikes during the late Noachian or early Hesperian, when surface pressures are thought to be substantially higher than present. We investigate background Martian atmospheres of 50 and 500 mbar CO2 with varying abundances of H2O and sulfur volatiles (H2S and SO2 mixing ratios of 10(-3) to 10(-6)). Results suggest that these sulfur volatile influxes, alone, could have been responsible for greenhouse warming up to 25 K above that caused by CO2. Including additional water vapor feedback, this process could have raised the early surface temperature above the freezing point for brines and possibly allowed transient liquid water on the Martian surface. Each temperature rise was likely to have been short-lived, however, due to brief residence times for sulfur volatiles in an optically thin atmosphere. C1 [Johnson, Sarah Stewart; Grove, Timothy L.; Zuber, Maria T.] MIT, Dept Earth Atmospher & Planetary Sci, Cambridge, MA 02139 USA. [Mischna, Michael A.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Johnson, SS (reprint author), MIT, Dept Earth Atmospher & Planetary Sci, 77 Massachusetts Ave, Cambridge, MA 02139 USA. EM ssj@mit.edu RI Grove, Timothy/M-9638-2013 OI Grove, Timothy/0000-0003-0628-1969 NR 92 TC 60 Z9 61 U1 0 U2 12 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 AUG 8 PY 2008 VL 113 IS E8 AR E08005 DI 10.1029/2007JE002962 PG 15 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 336CF UT WOS:000258341200001 ER PT J AU Park, J Bogard, DD Mikouchi, T Mckay, GA AF Park, Jisun Bogard, Donald D. Mikouchi, Takashi Mckay, Gordon A. TI Dhofar 378 Martian shergottite: Evidence of early shock melting SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID METEORITES; HISTORY; AGES; EJECTION; ORIGIN; NEON AB Shock heating of the Dhofar 378 (Dho 378) Martian shergottite produced melting, vesiculation, and flow of the plagioclase, which upon cooling recrystallized into complex textures. Heating experiments on the similar Zagami shergottite indicate that Dho 378 was shock heated to 1000-1100 degrees C and was cooled at similar to 2.5 degrees C/h. An (39)Ar-(40)Ar analysis of Dho 378 plagioclase indicates different Ar diffusion domains and K/Ca ratios. The lower-temperature phase defines an Ar-Ar isochron age of 141 +/- 32 Ma. The higher-temperature phase released more 40 Ar but does not define an age. The meteorite's thermal history was examined by constructing a generic model to compare cooling rates for objects of different sizes against fractional diffusion loss of Ar for different cooling times. Using gas diffusion parameter values measured for Dho 378, this model indicates that it is improbable that the major shock heating event occurred at the time that Dho 378 was ejected from Mars similar to 3 Ma ago. Rather, we suggest that the time of shock heating is probably given by its Ar-Ar age. For Dho 378 to cool sufficiently fast not to lose most of its (40)Ar similar to 3 Ma ago would require it to have been ejected into space as an impossibly small object. Larger and more reasonable Mars ejection sizes indicate that Dho 378 should have lost most of its (40)Ar. On the basis of plagioclase texture and Ar data, we suggest that a major impact event similar to 141 Ma ago melted Dho 378 plagioclase, degassed most of its (40)Ar, and deposited it in crater ejecta to cool. A smaller and later impact ejected it into space similar to 3 Ma ago. C1 [Park, Jisun; Bogard, Donald D.; Mckay, Gordon A.] NASA, Lyndon B Johnson Space Ctr, ARES, Houston, TX 77058 USA. [Mikouchi, Takashi] Univ Tokyo, Dept Earth & Planetary Sci, Tokyo 1130033, Japan. RP Park, J (reprint author), NASA, Lyndon B Johnson Space Ctr, ARES, Houston, TX 77058 USA. EM donald.d.bogard@nasa.gov NR 38 TC 11 Z9 11 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-PLANET JI J. Geophys. Res.-Planets PD AUG 8 PY 2008 VL 113 IS E8 AR E08007 DI 10.1029/2007JE003035 PG 12 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 336CF UT WOS:000258341200003 ER PT J AU Bishop, JL Dobrea, EZN McKeown, NK Parente, M Ehlmann, BL Michalski, JR Milliken, RE Poulet, F Swayze, GA Mustard, JF Murchie, SL Bibring, JP AF Bishop, Janice L. Dobrea, Eldar Z. Noe McKeown, Nancy K. Parente, Mario Ehlmann, Bethany L. Michalski, Joseph R. Milliken, Ralph E. Poulet, Francois Swayze, Gregg A. Mustard, John F. Murchie, Scott L. Bibring, Jean-Pierre TI Phyllosilicate diversity and past aqueous activity revealed at Mawrth Vallis, Mars SO SCIENCE LA English DT Article ID HYDROTHERMAL ALTERATION; INFRARED-SPECTROSCOPY; SMECTITES; BACTERIA; MINERALS; ORIGIN AB Observations by the Mars Reconnaissance Orbiter/Compact Reconnaissance Imaging Spectrometer for Mars in the Mawrth Vallis region show several phyllosilicate species, indicating a wide range of past aqueous activity. Iron/magnesium (Fe/Mg)-smectite is observed in light-toned outcrops that probably formed via aqueous alteration of basalt of the ancient cratered terrain. This unit is overlain by rocks rich in hydrated silica, montmorillonite, and kaolinite that may have formed via subsequent leaching of Fe and Mg through extended aqueous events or a change in aqueous chemistry. A spectral feature attributed to an Fe2+ phase is present in many locations in the Mawrth Vallis region at the transition from Fe/Mg-smectite to aluminum/silicon (Al/Si)-rich units. Fe2+-bearing materials in terrestrial sediments are typically associated with microorganisms or changes in pH or cations and could be explained here by hydrothermal activity. The stratigraphy of Fe/Mg-smectite overlain by a ferrous phase, hydrated silica, and then Al-phyllosilicates implies a complex aqueous history. C1 [Bishop, Janice L.] SETI Inst, Mountain View, CA 94043 USA. [Bishop, Janice L.] NASA, Ames Res Ctr, Mountain View, CA 94043 USA. [Dobrea, Eldar Z. Noe; Milliken, Ralph E.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [McKeown, Nancy K.] Univ Calif Santa Cruz, Dept Earth & Planetary Sci, Santa Cruz, CA 95064 USA. [Parente, Mario] Stanford Univ, Dept Elect Engn, Stanford, CA 94305 USA. [Ehlmann, Bethany L.; Mustard, John F.] Brown Univ, Dept Geol Sci, Providence, RI 02912 USA. [Michalski, Joseph R.; Poulet, Francois; Bibring, Jean-Pierre] Inst Astrophys Spatiale, F-91405 Orsay, France. [Swayze, Gregg A.] US Geol Survey, Lakewood, CO 80225 USA. [Murchie, Scott L.] Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. RP Bishop, JL (reprint author), SETI Inst, Mountain View, CA 94043 USA. EM jbishop@seti.org RI Murchie, Scott/E-8030-2015 OI Murchie, Scott/0000-0002-1616-8751 NR 23 TC 180 Z9 180 U1 5 U2 30 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 AUG 8 PY 2008 VL 321 IS 5890 BP 830 EP 833 DI 10.1126/science.1159699 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 334ZQ UT WOS:000258261000044 PM 18687963 ER PT J AU Kwok, R Cunningham, GF AF Kwok, R. Cunningham, G. F. TI ICESat over Arctic sea ice: Estimation of snow depth and ice thickness SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID OCEAN; VARIABILITY; BUDGET; COVER; LAND AB Starting with retrieved freeboards from four ICESat campaigns (ON05, October/November 2005; FM06, February/March 2006; ON06, October/November 2006; and MA07, March/April 2007) we estimate their ice thicknesses using constructed fields of daily snow depth and compare them with ice drafts from moored upward-looking sonars. The methodologies, considerations, and assumptions used in the conversion of freeboard to ice thickness are discussed. The thickness distributions of the Arctic multiyear and seasonal ice covers are contrasted. Broadly, the resulting fields seem seasonally and interannually consistent in terms of thickness, growth and ice production. We find mean thicknesses of 2.15/2.46m in ON05/FM06 and an overall thinner ice cover of 1.96/2.37min ON06/MA07. This represents a growth of similar to 0.3 m and similar to 0.4 m during the similar to 4-month intervals of the ON05-FM06 and ON06-MA07 campaigns, respectively. After accounting for data gaps, we compute overall Arctic Ocean ice volumes of 11,318, 14,075, 10,626, and 13,891 km 3 for the ON05, FM06, ON06, and MA07 campaigns, respectively. The higher total volume in ON05 (versus ON06) can be attributed to the higher multiyear ice coverage that fall: 37% versus 31%. However, the higher estimated ice production (less export) during the second year (3265 versus 2757 km3) is likely due to the higher growth rate over the larger expanse of seasonal sea ice during the fall and winter. Inside a 25-km radius of two mooring locations in the Beaufort Sea, the estimated mean ICESat ice drafts from ON05 and FM06 are within 0.5 m of those measured at the moorings. C1 [Kwok, R.; Cunningham, G. F.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Kwok, R (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM ron.kwok@jpl.nasa.gov RI Kwok, Ron/A-9762-2008 OI Kwok, Ron/0000-0003-4051-5896 NR 30 TC 109 Z9 118 U1 3 U2 22 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 AUG 7 PY 2008 VL 113 IS C8 AR C08010 DI 10.1029/2008JC004753 PG 17 WC Oceanography SC Oceanography GA 336CA UT WOS:000258340700004 ER PT J AU Schmidt, JM Gopalswamy, N AF Schmidt, J. M. Gopalswamy, N. TI \Synthetic radio maps of CME-driven shocks below 4 solar radii heliocentric distance SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID CORONAL MASS EJECTIONS; MAGNETIC RECONNECTION; INTERPLANETARY SHOCKS; HARMONIC EMISSION; DYNAMIC SPECTRA; LARGE-ANGLE; BURSTS; WIND; REGION; CLOUD AB [1] We present 2 1/2 D numerical MagnetoHydroDynamic (MHD) simulations of coronal mass ejections (CMEs) in conjunction with plasma simulations of radio emission from the CME-driven shocks. The CME-driven shock extends to an almost spherical shape during the temporal evolution of the CME. Our plasma simulations can reproduce the dynamic spectra of coronal type II radio bursts, with the frequency drift rates corresponding to the shock speeds. We find further, that the CME-driven shock is an effective radio emitter at metric wavelengths, when the CME has reached a heliocentric distance of about two solar radii (R(circle dot)). We apply our simulation results to explain the radio images of type II bursts obtained by radio heliographs, in particular to the banana-shaped images of radio sources associated with fast CMEs. C1 [Schmidt, J. M.; Gopalswamy, N.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Schmidt, JM (reprint author), NASA, Goddard Space Flight Ctr, Code 695,8800 Greenbelt Rd, Greenbelt, MD 20771 USA. EM jschmidt@ssedmail.gsfc.nasa.gov; gopals@ssedmail.gsfc.nasa.gov RI Gopalswamy, Nat/D-3659-2012; OI Schmidt, Joachim/0000-0002-7927-0665 NR 50 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-SPACE JI J. Geophys. Res-Space Phys. PD AUG 7 PY 2008 VL 113 IS A8 AR A08104 DI 10.1029/2007JA013002 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 336CM UT WOS:000258341900003 ER PT J AU Lindsay, RW Kwok, R de Steur, L Meier, W AF Lindsay, R. W. Kwok, R. de Steur, L. Meier, W. TI Halo of ice deformation observed over the Maud Rise seamount SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID WEDDELL POLYNYA; SEA; MOTION; MODEL; CIRCULATION; IMAGERY; FLUX; SAR AB A distinctive halo of sea ice deformation was observed above the Maud Rise seamount in the eastern Weddell Sea in the winter of 2005. The deformation halo is coincident with a halo of low mean ice concentration that is often observed in the region. Monthly mean ice vorticity estimates for the months July through November reveal the deformation zone most clearly in an arc about 100 km northwest of the seamount where there is a strong gradient in the bathymetry at depths of 3000-5000 m. The deformation was computed from satellite-based ice motion vectors derived from Envisat Synthetic Aperture Radar backscatter images. The deformation halo is evidence of a Taylor cap circulation over the seamount, which has been described and analyzed with modeling studies and concurrent oceanographic observations obtained during an extensive field campaign. C1 [Lindsay, R. W.] Univ Washington, Appl Phys Lab, Polar Sci Ctr, Seattle, WA 98105 USA. [Kwok, R.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [de Steur, L.] Norwegian Polar Res Inst, N-9296 Tromso, Norway. [Meier, W.] Univ Colorado, Natl Snow & Ice Data Ctr, Boulder, CO 80309 USA. RP Lindsay, RW (reprint author), Univ Washington, Appl Phys Lab, Polar Sci Ctr, Seattle, WA 98105 USA. RI Kwok, Ron/A-9762-2008; Lindsay, Ron/S-9083-2016; OI Kwok, Ron/0000-0003-4051-5896; de Steur, Laura/0000-0002-6043-7920; Meier, Walter/0000-0003-2857-0550 NR 28 TC 5 Z9 6 U1 0 U2 0 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 AUG 6 PY 2008 VL 35 IS 15 AR L15501 DI 10.1029/2008GL034629 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 336BC UT WOS:000258338300004 ER PT J AU Kondo, Y Hudman, RC Nakamura, K Koike, M Chen, G Miyazaki, Y Takegawa, N Blake, DR Simpson, IJ Ko, M Kita, K Shirai, T Kawakami, S AF Kondo, Y. Hudman, R. C. Nakamura, K. Koike, M. Chen, G. Miyazaki, Y. Takegawa, N. Blake, D. R. Simpson, I. J. Ko, M. Kita, K. Shirai, T. Kawakami, S. TI Mechanisms that influence the formation of high-ozone regions in the boundary layer downwind of the Asian continent in winter and spring SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID TROPOSPHERIC NITROGEN-DIOXIDE; WESTERN NORTH PACIFIC; AIR-QUALITY; TRANSPORT MODEL; UNITED-STATES; HO2 RADICALS; GLOBAL-MODEL; EAST-ASIA; CHEMISTRY; AEROSOLS AB The seasonal variation of ozone (O-3) in the boundary layer (BL) over the western Pacific is investigated using a chemistry-transport model. The model results for January and April-May 2002 were evaluated by comparison with PEACE aircraft observations. In January, strong northwesterlies efficiently transported NOx from the continent, leading to an O-3 increase of approximately 5-10 ppbv over a distance of about 3000 km. In April, southwesterlies dominated due to anticyclone development over the western Pacific. Along this flow, O-3 continued to be produced by NOx emitted from East Asia. This resulted in the formation of a high-O-3 (> 50 ppbv) region extending along the coastal areas of East Asia. This seasonal change in O-3 was driven in part by a change in the net O-3 production rate due to increases in solar UV and H2O. Its exact response depended on the NOx values in the BL. The net O-3 production rate increased between winter and spring over the Asian continent and decreased over the remote western Pacific. Model simulations show that about 25% of the total O-3 (of 10-20 ppbv) increase over the coastal region of Northeast Asia was due to local production from NOx emissions from China, and the rest was due to changes in background levels as well as emissions from Korea, Japan, and east Siberia. Uplift of BL air over Asia, horizontal transport in the free troposphere, and subsidence were the principal mechanisms of transporting Asian O-3 to the central and eastern North Pacific. C1 [Kondo, Y.; Miyazaki, Y.; Takegawa, N.] Univ Tokyo, Adv Sci & Technol Res Ctr, Meguro Ku, Tokyo 1538904, Japan. [Hudman, R. C.] Harvard Univ, Div Engn & Appl Sci, Cambridge, MA 02138 USA. [Koike, M.] Univ Tokyo, Grad Sch Sci, Dept Earth & Planetary Sci, Bunkyo Ku, Tokyo 1130033, Japan. [Chen, G.; Ko, M.] NASA, Langley Res Ctr, Hampton, VA 23681 USA. [Blake, D. R.; Simpson, I. J.] Univ Calif Irvine, Dept Chem, Irvine, CA 92697 USA. [Kita, K.] Ibaraki Univ, Dept Environm Sci, Grad Sch Sci, Bunkyo Ku, Mito, Ibaraki 3108512, Japan. [Shirai, T.; Kawakami, S.] Japan Aerosp Explorat Agcy, Earth Observat Res & Applicat Ctr, Tokyo, Japan. RP Kondo, Y (reprint author), Univ Tokyo, Adv Sci & Technol Res Ctr, Meguro Ku, 4-6-1 Komaba, Tokyo 1538904, Japan. EM y.kondo@atmos.rcast.u-tokyo.ac.jp; hudman@fas.harvard.edu; kenji.nakamura@aoni.waseda.jp; koike@eps.s.u-tokyo.ac.jp; g.chen@larc.nasa.gov; yuzom@atmos.rcast.u-tokyo.ac.jp; takegawa@atmos.rcast.u-tokyo.ac.jp; drblake@uci.edu; isimpson@uci.edu; malcolm.k.ko@larc.nasa.gov; kita@env.sci.ibaraki.ac.jp; tshirai@nies.go.jp RI Hudman, Rynda/C-6118-2009; Koike, Makoto/F-4366-2011; Kondo, Yutaka/D-1459-2012; Ko, Malcolm/D-5898-2015; Miyazaki, Yuzo/C-6920-2010 NR 74 TC 2 Z9 2 U1 2 U2 6 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 AUG 6 PY 2008 VL 113 IS D15 AR D15304 DI 10.1029/2007JD008978 PG 25 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 336BI UT WOS:000258338900001 ER PT J AU Ieda, A Fairfield, DH Slavin, JA Liou, K Meng, CI Machida, S Miyashita, Y Mukai, T Saito, Y Nose, M Shue, JH Parks, GK Fillingim, MO AF Ieda, A. Fairfield, D. H. Slavin, J. A. Liou, K. Meng, C. -I. Machida, S. Miyashita, Y. Mukai, T. Saito, Y. Nose, M. Shue, J. -H. Parks, G. K. Fillingim, M. O. TI Longitudinal association between magnetotail reconnection and auroral breakup based on Geotail and Polar observations SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID TRAVELING COMPRESSION REGIONS; EARTHWARD FLOW BURSTS; SUBSTORM ONSET; MAGNETIC-FIELD; MAGNETOSPHERIC SUBSTORM; ULTRAVIOLET IMAGER; PLASMOID EJECTION; INTENSIFICATIONS; PULSATIONS; SIGNATURES AB The dawn-dusk locations of reconnection in the near-earth magnetotail at the time of isolated auroral breakup are studied to clarify whether breakup is always accompanied by reconnection. The near-earth reconnection is identified by tailward plasma flows faster than 200 km/s with southward magnetic field. We first identified 66 breakups in the Polar ultraviolet imager observations of the nightside polar ionosphere. We then studied tailward flows during breakups using Geotail in situ observations of the plasma sheet between 25 and 31 RE down the tail. It was found that the dawn-dusk (Y) locations of relatively fast (>= 400 km/s) tailward flows were associated with breakup magnetic local time (MLT) by a regression line of YAGSM = -5.7 x (MLT + 0.6) R(E) with a correlation coefficient of 0.8. Most tailward flows were observed within 5 R(E) of the modeled Y locations, where tailward flows occurred in 88% of the 26 cases of breakups between 22 and 0 MLT. It is thus inferred that in most cases, breakup is accompanied by tailward flow near the breakup MLT with its dawn-dusk dimension similar to 10 R(E). There were only two events without tailward flows in the region where flows have been expected. These two events were an earthward flow event and a traveling compression region event, which are not inconsistent with the initiation of the near-earth reconnection. Auroral breakup is thus likely to always be accompanied by near-earth reconnection near breakup MLT. It is also inferred that reconnection and breakup occur simultaneously within a few minutes, assuming a time delay between reconnection onset and the arrival of tailward flows at satellite locations. C1 [Ieda, A.] Nagoya Univ, Solar Terr Environm Lab, Chikusa Ku, Nagoya, Aichi 4648601, Japan. [Fairfield, D. H.; Slavin, J. A.] NASA, Goddard Space Flight Ctr, Heliophys Sci Div, Greenbelt, MD 20771 USA. [Liou, K.; Meng, C. -I.] Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. [Machida, S.] Kyoto Univ, Dept Geophys, Sakyo Ku, Kyoto 6068502, Japan. [Miyashita, Y.; Mukai, T.; Saito, Y.] Japan Aerosp Explorat Agcy, Inst Space & Astronaut Sci, Sagamihara, Kanagawa 2298510, Japan. [Nose, M.] Kyoto Univ, Data Anal Ctr Geomagnetism & Space Magnetism, Grad Sch Sci, Sakyo Ku, Kyoto 6068502, Japan. [Shue, J. -H.] Natl Cent Univ, Inst Space Sci, Jhongli 32001, Taoyuan County, Taiwan. [Parks, G. K.; Fillingim, M. O.] Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. RP Ieda, A (reprint author), Nagoya Univ, Solar Terr Environm Lab, Chikusa Ku, Nagoya, Aichi 4648601, Japan. EM ieda@stelab.nagoya-u.ac.jp RI Slavin, James/H-3170-2012; Nose, Masahito/B-1900-2015; Liou, Kan/C-2089-2016 OI Slavin, James/0000-0002-9206-724X; Nose, Masahito/0000-0002-2789-3588; Liou, Kan/0000-0001-5277-7688 NR 55 TC 19 Z9 20 U1 3 U2 6 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 AUG 6 PY 2008 VL 113 IS A8 AR A08207 DI 10.1029/2008JA013127 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 336CL UT WOS:000258341800004 ER PT J AU Guzik, TG Adams, JH Ahn, HS Bashindzhagyan, GL Batkov, KE Chang, J Christl, M Fazely, AR Ganel, O Gunashingha, RM Isbert, J Kim, KC Kouznetsov, EN Panasyuk, MI Panov, AD Schmidt, WKH Seo, ES Sokolskaya, NV Watts, JW Wefel, JP Wu, J Zatsepin, VI AF Guzik, T. G. Adams, J. H., Jr. Ahn, H. S. Bashindzhagyan, G. L. Batkov, K. E. Chang, J. Christl, M. Fazely, A. R. Ganel, O. Gunashingha, R. M. Isbert, J. Kim, K. C. Kouznetsov, 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 Enhancing the ATIC charge resolution SO ADVANCES IN SPACE RESEARCH LA English DT Article DE ballooning; ATIC; particle detectors; hodoscope; charge resolution ID SILICON MATRIX; DETECTOR AB The Advanced Thin Ionization Calorimeter (ATIC) experiment is designed to investigate the charge composition and energy spectra of primary cosmic rays over the energy range from about 10(11) to 10(14) eV during Long Duration Balloon (LDB) flights from McMurdo, Antarctica. Currently, analysis from the ATIC-1 test flight and ATIC-2 science flight is underway and preparation for a second science flight is in progress. Charge identification of the incident cosmic ray is accomplished, primarily, by a pixilated Silicon Matrix detector located at the very top of the instrument. While it has been shown that the Silicon Matrix detector provides good charge identification even in the presence of electromagnetic shower backscatter from tile calorimeter, the detector only measures the charge once. In this paper, we examine use of the top scintillator hodoscope detector to provide a second measure of the cosmic ray charge and, thus, improve the ATIC charge identification. (c) 2007 COSPAR. Published by Elsevier Ltd. All rights reserved. C1 [Adams, J. H., Jr.; Christl, M.; Watts, J. W.] NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. [Guzik, T. G.; Isbert, J.; Wefel, J. P.] Louisiana State Univ, Dept Phys & Astron, Baton Rouge, LA 70803 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.; Batkov, K. E.; Kouznetsov, E. N.; Panasyuk, M. I.; Panov, A. D.; Sokolskaya, N. V.; Zatsepin, V. I.] Moscow MV Lomonosov State Univ, Skobeltsyn Inst Nucl Phys, Moscow 119899, Russia. [Chang, J.] Chinese Acad Sci, Purple Mt Observ, Nanjing 210008, Peoples R China. [Chang, J.; Schmidt, W. K. H.] Max Planck Inst Solar Syst Res, D-37191 Katlenburg Lindau, Germany. [Fazely, A. R.; Gunashingha, R. M.] So Univ, Dept Phys, Baton Rouge, LA 70813 USA. RP Guzik, TG (reprint author), Louisiana State Univ, Dept Phys & Astron, Baton Rouge, LA 70803 USA. EM guzik@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 NR 20 TC 1 Z9 1 U1 0 U2 2 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 AUG 5 PY 2008 VL 42 IS 3 BP 424 EP 430 DI 10.1016/j.asr.2007.08.017 PG 7 WC Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA 326UL UT WOS:000257684300004 ER PT J AU Chang, J Adams, JH Ahn, HS Bashindzhagyan, GL Batkov, KE Christl, M Fazely, AR Ganel, O Gunashingha, RM Guzik, TG Isbert, J Kim, KC Kouznetsov, EN Lin, ZW 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. Batkov, K. E. Christl, M. Fazely, A. R. Ganel, O. Gunashingha, R. M. Guzik, T. G. Isbert, J. Kim, K. C. Kouznetsov, E. N. Lin, Z. W. Panasyuk, M. I. Panov, A. D. Schmidt, W. K. H. Seo, E. S. Sokolskaya, N. V. Watts, John W. Wefel, J. P. Wu, J. Zatsepin, V. I. TI Resolving electrons from protons in ATIC SO ADVANCES IN SPACE RESEARCH LA English DT Article DE electron; simulation; beam test; balloon flight AB The Advanced Thin Ionization Calorimeter (ATIC) experiment is designed for high energy cosmic ray ion detection. The possibility to identify high energy primary cosmic ray electrons in the presence of the 'background' of cosmic ray protons has been studied by simulating nuclear-electromagnetic cascade showers using the FLUKA Monte Carlo simulation code. The ATIC design, consisting of a graphite target and an energy detection device, a totally active calorimeter built up of 2.5 cm x 2.5 cm x 25.0 cm BGO scintillator bars, gives sufficient information to distinguish electrons from protons. While identifying about 80% of electrons as such, only about 2 in 10,000 protons (@ 150 GeV) will mimic electrons. In September of 1999 ATIC was exposed to high-energy electron and proton beams at the CERN H2 beam line, and this data confirmed the electron detection capabilities of ATIC. From 2000-12-28 to 2001-01-13 ATIC was flown as a long duration balloon test flight from McMurdo, Antarctica, recording over 360 h of data and allowing electron separation to be confirmed in the flight data. In addition, ATIC electron detection capabilities can be checked by atmospheric gamma-ray observations. (c) 2007 COSPAR. Published by Elsevier Ltd. All rights reserved. C1 [Chang, J.] Chinese Acad Sci, Purple Mt Observ, Space Astron Div, Jiangsu 210008, Peoples R China. [Chang, J.; Schmidt, W. K. H.] Max Planck Inst Solar Syst Res, Katlenburg Lindau, Germany. [Adams, J. H., Jr.; Watts, John W.] NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. [Ahn, H. S.; Ganel, O.; Kim, K. C.; Seo, E. S.] Univ Maryland, Inst Phys Sci & Technol, College Pk, MD 20742 USA. [Bashindzhagyan, G. L.; Batkov, K. E.; Kouznetsov, E. N.; Panasyuk, M. I.; Panov, A. D.; Sokolskaya, N. V.; Zatsepin, V. I.] Moscow MV Lomonosov State Univ, Skobeltsyn Inst Nucl Phys, Moscow, Russia. [Fazely, A. R.; Gunashingha, R. M.] So Univ, Dept Phys, Baton Rouge, LA USA. [Guzik, T. G.; Isbert, J.; Wefel, J. P.; Wu, J.] Louisiana State Univ, Dept Phys & Astron, Baton Rouge, LA 70803 USA. [Lin, Z. W.] Univ Alabama, Huntsville, AL 35899 USA. RP Chang, J (reprint author), Chinese Acad Sci, Purple Mt Observ, Space Astron Div, Beijing W Rd 2, Jiangsu 210008, Peoples R China. EM chang@pmo.ac.cn 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 NR 9 TC 9 Z9 9 U1 0 U2 4 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 AUG 5 PY 2008 VL 42 IS 3 BP 431 EP 436 DI 10.1016/j.asr.2007.06.012 PG 6 WC Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA 326UL UT WOS:000257684300005 ER PT J AU Isbert, J Adams, JH Ahn, HS Bashindzhagyan, GL Batkov, KE Christl, M Fazely, AR Ganel, O Gunashingha, RM Guzik, TG Chang, J Kim, KC Kouznetsov, EN Lin, ZW Panasyuk, MI Panov, AD Schmidt, WKH Seo, ES Sokolskaya, NV Watts, JW Wefel, JP Wu, J Zatsepin, VI AF Isbert, J. Adams, J. H., Jr. Ahn, H. S. Bashindzhagyan, G. L. Batkov, K. E. Christl, M. Fazely, A. R. Ganel, O. Gunashingha, R. M. Guzik, T. G. Chang, J. Kim, K. C. Kouznetsov, E. N. Lin, Z. W. Panasyuk, M. I. Panov, A. D. Schmidt, W. K. H. Seo, E. S. Sokolskaya, N. V. Watts, John W. Wefel, J. P. Wu, J. Zatsepin, V. I. TI Temperature effects in the ATIC BGO calorimeter SO ADVANCES IN SPACE RESEARCH LA English DT Article DE cosmic rays; high-altitude ballooning; BGO temperature dependence AB The Advanced Thin Ionization Calorimeter (ATIC) Balloon Experiment had a successful test flight and a science flight in 2000-01 and 2002-03 and an unsuccessful launch in 2005-06 from McMurdo, Antarctica, returning 16 and 19 days of flight data. ATIC is designed to measure the spectra of cosmic rays (protons to iron). The instrument is composed of a Silicon matrix detector followed by a carbon target interleaved with scintillator tracking layers and a segmented BGO calorimeter composed of 320 individual crystals totaling 18 radiation lengths to determine the particle energy. BGO (Bismuth Germanate) is an inorganic scintillation crystal and its light output depends not only on the energy deposited by particles but also on the temperature of the crystal. The temperature of balloon instruments during flight is not constant due to sun angle variations as well as differences in albedo from the ground. The change in output for a given energy deposit in the crystals in response to temperature variations was determined. (c) 2007 COSPAR. Published by Elsevier Ltd. All rights reserved. C1 [Isbert, J.; Guzik, T. G.; Wefel, J. P.] Louisiana State Univ, Dept Phys & Astron, Baton Rouge, LA 70803 USA. [Christl, M.; Watts, John W.] NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. [Chang, J.; Schmidt, W. K. H.] Max Planck Inst Solar Syst Res, Katlenburg Lindau, Germany. [Chang, J.] Chinese Acad Sci, Purple Mt Observ, Beijing 100864, Peoples R China. [Adams, J. H., Jr.] Univ Alabama, Huntsville, AL 35899 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.; Batkov, K. E.; Kouznetsov, E. N.; Panasyuk, M. I.; Panov, A. D.; Sokolskaya, N. V.; Zatsepin, V. I.] Moscow MV Lomonosov State Univ, Skobeltsyn Inst Nucl Phys, Moscow, Russia. [Fazely, A. R.; Gunashingha, R. M.; Lin, Z. W.] So Univ, Dept Phys, Baton Rouge, LA USA. RP Isbert, J (reprint author), Louisiana State Univ, Dept Phys & Astron, Baton Rouge, LA 70803 USA. EM isbert@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 NR 5 TC 5 Z9 5 U1 0 U2 2 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 AUG 5 PY 2008 VL 42 IS 3 BP 437 EP 441 DI 10.1016/j.asr.2007.12.014 PG 5 WC Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA 326UL UT WOS:000257684300006 ER PT J AU Yamamoto, A Abe, K Fuke, H Haino, S Hams, T Hasegawa, M Horikoshi, A Kim, KC Kusumoto, A Lee, MH Makida, Y Matsuda, S Matsukawa, Y Mitchell, JW Moiseev, A Nishimura, J Nozaki, M Orito, R Orito, S Ormes, JF Sakai, K Sanuki, T Sasaki, M Seo, ES Shikaze, Y Shinoda, R Streitmatter, RE Suzuki, J Tanaka, K Thakur, N Yamagami, T Yoshida, T Yoshimura, K AF Yamamoto, A. Abe, K. Fuke, H. Haino, S. Hams, T. Hasegawa, M. Horikoshi, A. Kim, K. C. Kusumoto, A. Lee, M. H. Makida, Y. Matsuda, S. Matsukawa, Y. Mitchell, J. W. Moiseev, A. Nishimura, J. Nozaki, M. Orito, R. Orito, S. Ormes, J. F. Sakai, K. Sanuki, T. Sasaki, M. Seo, E. S. Shikaze, Y. Shinoda, R. Streitmatter, R. E. Suzuki, J. Tanaka, K. Thakur, N. Yamagami, T. Yoshida, T. Yoshimura, K. TI Search for primordial antiparticles with BESS SO ADVANCES IN SPACE RESEARCH LA English DT Article DE antiparticle; antiproton; cosmic-ray; primordial black hole; superconducting spectrometer; long duration balloon flight; BESS ID RAY ANTIPROTON SPECTRUM; PARTICLE ASTROPHYSICS; COSMIC-RAYS; SECONDARY ANTIPROTONS; PRECISE MEASUREMENTS; SOLAR MODULATION; ONBOARD BESS; SPECTROMETER; FLUX; ANTIHELIUM AB The Balloon-borne Experiment with a Superconducting Spectrometer (BESS) has been carried out to search for primordial antiparticles in cosmic rays. In ten flights from 1993 to 2004, it measured the cosmic-ray.antiproton spectrum in the energy range 0.1-4.2 GeV at various solar activity conditions. It also searched for antideuterons and antilielium nuclei, and it made precise measurement of cosmicray particle spectra. The BESS program has been extended to long duration balloon (LDB) flights in Antarctica (BESS-Polar) with the goal of achieving unprecedented sensitivity in the search for primordial antiparticles. This report describes recent results from BESS and progress of the BESS-Polar program. (c) 2008 Published by Elsevier Ltd on behalf of COSPAR. C1 [Yamamoto, A.; Haino, S.; Hasegawa, M.; Horikoshi, A.; Makida, Y.; Matsuda, S.; Nozaki, M.; Suzuki, J.; Tanaka, K.; Yoshimura, K.] High Energy Accelerator Res Org KEK, Tsukuba, Ibaraki 3050801, Japan. [Abe, K.; Kusumoto, A.; Matsukawa, Y.; Orito, R.; Shikaze, Y.] Kobe Univ, Kobe, Hyogo 657850, 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.; 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.; Orito, S.; Sakai, K.; Sanuki, T.; Shinoda, R.] Univ Tokyo, Bunkyo Ku, Tokyo 1130044, Japan. [Ormes, J. F.; Thakur, N.] Univ Denver, Denver, CO 80208 USA. RP Yamamoto, A (reprint author), High Energy Accelerator Res Org KEK, Tsukuba, Ibaraki 3050801, Japan. EM akira.yamamoto@kek.jp OI Seo, Eun-Suk/0000-0001-8682-805X NR 60 TC 7 Z9 7 U1 0 U2 3 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 AUG 5 PY 2008 VL 42 IS 3 BP 442 EP 449 DI 10.1016/j.asr.2007.04.069 PG 8 WC Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA 326UL UT WOS:000257684300007 ER PT J AU Sasaki, M Haino, S Abe, K Fuke, H Hams, T Kim, KC Lee, MH Makida, Y Matsuda, S Mitchell, JW Moiseev, AA Nishimura, J Nozaki, M Orito, S Ormes, JF Sanuki, T Seo, ES Shikaze, Y Streitmatter, RE Suzuki, J Tanaka, K Yamagami, T Yamamoto, A Yoshida, T Yoshimura, K AF Sasaki, M. Haino, S. Abe, K. Fuke, H. Hams, T. Kim, K. C. Lee, M. H. Makida, Y. Matsuda, S. Mitchell, J. W. Moiseev, A. A. Nishimura, J. Nozaki, M. Orito, S. Ormes, J. F. Sanuki, T. Seo, E. S. Shikaze, Y. Streitmatter, R. E. Suzuki, J. Tanaka, K. Yamagami, T. Yamamoto, A. Yoshida, T. Yoshimura, K. TI Search for antihelium: Progress with BESS SO ADVANCES IN SPACE RESEARCH LA English DT Article DE cosmic ray; antimatter; antihelium; BESS; BESS-TeV; BESS-Polar ID COSMIC-RAYS; FLUX AB In this paper, we report searches for antilielium in cosmic rays using two recently flown magnetic rigidity spectrometers. BESS-TeV had extended rigidity with all MDR of 1.4 TV and had a flight duration of one day. BESS-Polar was optimized for collecting power. It was flown for 8.5 days and had an MDR of 240 GV. Tile former flight allows us to explore a previously unexplored rigidity band and the latter flight yields a factor of three improvement in the overall BESS limit. No antilielium candidate was found in the rigidity ranges of 1-500 GV, and 0.6-20 GV, among 7 x 10(4) events taken with BESS-TeV, and 8 X 10(6) events taken with BESS-Polar, respectively. (c) 2007 COSPAR. Published by Elsevier Ltd. All rights reserved. C1 [Sasaki, M.; Hams, T.; Mitchell, J. W.; Moiseev, A. A.; Streitmatter, R. E.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Sasaki, M.; Hams, T.] Univ Space Res Assoc, Columbia, MD 21044 USA. [Haino, S.; Makida, Y.; Matsuda, S.; Nozaki, M.; Suzuki, J.; Tanaka, K.; Yamamoto, A.; Yoshimura, K.] High Energy Accelerator Res Org, Tsukuba, Ibaraki 3050801, Japan. [Abe, K.; Shikaze, Y.] Kobe Univ, Kobe, Hyogo 6578501, Japan. [Fuke, H.; Yamagami, T.; Yoshida, T.] Inst Space & Astronaut Sci ISAS JAXA, Kanagawa 2298501, Japan. [Kim, K. C.; Lee, M. H.; Seo, E. S.] Univ Maryland, College Pk, MD 20742 USA. [Nishimura, J.; Orito, S.; Sanuki, T.] Univ Tokyo, Bunkyo Ku, Tokyo 1130033, Japan. [Ormes, J. F.] Univ Denver, Denver, CO 80208 USA. RP Sasaki, M (reprint author), NASA, Goddard Space Flight Ctr, Code 661, Greenbelt, MD 20771 USA. EM sasaki@milkyway.gsfc.nasa.gov OI Seo, Eun-Suk/0000-0001-8682-805X NR 11 TC 15 Z9 16 U1 3 U2 6 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 AUG 5 PY 2008 VL 42 IS 3 BP 450 EP 454 DI 10.1016/j.asr.2007.09.012 PG 5 WC Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA 326UL UT WOS:000257684300008 ER PT J AU Chepfer, H Bony, S Winker, D Chiriaco, M Dufresne, JL Seze, G AF Chepfer, H. Bony, S. Winker, D. Chiriaco, M. Dufresne, J. -L. Seze, G. TI Use of CALIPSO lidar observations to evaluate the cloudiness simulated by a climate model SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID CLOUDS; RETRIEVALS; ECMWF; ISCCP; MM5 AB New space-borne active sensors make it possible to observe the three-dimensional structure of clouds. Here we use CALIPSO lidar observations together with a lidar simulator to evaluate the cloudiness simulated by a climate model: modeled atmospheric profiles are converted to an ensemble of subgrid-scale attenuated backscatter lidar signals from which a cloud fraction is derived. Except in regions of persistent thick upper-level clouds, the cloud fraction diagnosed through this procedure is close to that actually predicted by the model. A fractional cloudiness is diagnosed consistently from CALIPSO data at a spatio-temporal resolution comparable to that of the model. The comparison of the model's cloudiness with CALIPSO data reveals discrepancies more pronounced than in previous model evaluations based on passive observations. This suggests that space-borne lidar observations constitute a powerful tool for the evaluation of clouds in large-scale models, including marine boundary-layer clouds. C1 [Chepfer, H.; Bony, S.; Dufresne, J. -L.; Seze, G.] Univ Paris 06, CNRS, LMD IPSL, F-75252 Paris, France. [Chiriaco, M.] Univ Versailles St Quentin, CNRS, SA IPSL, F-75252 Paris, France. [Winker, D.] NASA, LaRC, Hampton, VA 23681 USA. RP Chepfer, H (reprint author), Univ Paris 06, CNRS, LMD IPSL, F-75252 Paris, France. EM chepfer@lmd.polytechnique.fr RI Dufresne, Jean-Louis/I-5616-2015; OI Dufresne, Jean-Louis/0000-0003-4764-9600; Bony, Sandrine/0000-0002-4791-4438 NR 22 TC 83 Z9 83 U1 1 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 AUG 5 PY 2008 VL 35 IS 15 AR L15704 DI 10.1029/2008GL034207 PG 6 WC Geosciences, Multidisciplinary SC Geology GA 336BB UT WOS:000258338200002 ER PT J AU Kharecha, PA Hansen, JE AF Kharecha, Pushker A. Hansen, James E. TI Implications of "peak oil'' for atmospheric CO2 and climate SO GLOBAL BIOGEOCHEMICAL CYCLES LA English DT Article ID CARBON; FEEDBACK; GASES; MODEL AB Unconstrained CO2 emission from fossil fuel burning has been the dominant cause of observed anthropogenic global warming. The amounts of "proven'' and potential fossil fuel reserves are uncertain and debated. Regardless of the true values, society has flexibility in the degree to which it chooses to exploit these reserves, especially unconventional fossil fuels and those located in extreme or pristine environments. If conventional oil production peaks within the next few decades, it may have a large effect on future atmospheric CO2 and climate change, depending upon subsequent energy choices. Assuming that proven oil and gas reserves do not greatly exceed estimates of the Energy Information Administration, and recent trends are toward lower estimates, we show that it is feasible to keep atmospheric CO2 from exceeding about 450 ppm by 2100, provided that emissions from coal, unconventional fossil fuels, and land use are constrained. Coal-fired power plants without sequestration must be phased out before midcentury to achieve this CO2 limit. It is also important to "stretch'' conventional oil reserves via energy conservation and efficiency, thus averting strong pressures to extract liquid fuels from coal or unconventional fossil fuels while clean technologies are being developed for the era "beyond fossil fuels''. We argue that a rising price on carbon emissions is needed to discourage conversion of the vast fossil resources into usable reserves, and to keep CO2 beneath the 450 ppm ceiling. C1 [Kharecha, Pushker A.; Hansen, James E.] NASA, Goddard Inst Space Studies, New York, NY 10025 USA. [Kharecha, Pushker A.; Hansen, James E.] Columbia Univ Earth Inst, New York, NY 10025 USA. RP Kharecha, PA (reprint author), NASA, Goddard Inst Space Studies, 2880 Broadway, New York, NY 10025 USA. EM pushker@giss.nasa.gov NR 48 TC 40 Z9 40 U1 1 U2 20 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 AUG 5 PY 2008 VL 22 IS 3 AR GB3012 DI 10.1029/2007GB003142 PG 10 WC Environmental Sciences; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Geology; Meteorology & Atmospheric Sciences GA 336BG UT WOS:000258338700002 ER PT J AU Desai, MI Mason, GM Muller-Mellin, R Korth, A Mall, U Dwyer, JR von Rosenvinge, TT AF Desai, M. I. Mason, G. M. Mueller-Mellin, R. Korth, A. Mall, U. Dwyer, J. R. von Rosenvinge, T. T. TI The spatial distribution of upstream ion events from the Earth's bow shock measured by ACE, Wind, and STEREO SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID STATE HEAVY-IONS; MAGNETIC-FIELD; ENERGETIC PARTICLES; ALFVEN WAVES; SOLAR-WIND; PROTONS; ACCELERATION; SPACECRAFT; INSTRUMENT; WIND/STEP AB Using simultaneous measurements of >40 keV upstream ions observed at ACE, Wind, and STEREO-A during the solar minimum period of 2007, day 1 through 2007, day 181, we investigate their spatial distributions by calculating their occurrence probabilities as a function of lateral and radial separation between L1 and STEREO-A. Our main results are given as follows: (1) STEREO-A observed upstream events even when it was separated from Earth by similar to 1750 R(E) and similar to 3800 R(E) in the radial and lateral directions, respectively. (2) The occurrence probability (similar to 20-30%) for measuring simultaneous upstream events at L1 and STEREO-A was far greater than that expected from accidental coincidences. (3) The occurrence rate of simultaneous upstream events at L1 and STEREO-A is significantly higher inside rarefaction regions of high-speed solar wind flows (>500 km s(-1)) that follow corotating compression regions and when there exist antisunward propagating Alfven waves. These new results confirm the global nature of the source region and place limits on the spatial size of the interplanetary structures that could either accelerate the ions in the first place or at the very least provide them with easier access by facilitating their scatter-free transport from the Earth's foreshock into the far upstream regions traversed by STEREO-A. We suggest that the existence of large amplitude Alfven waves with spatial scales of the order of 0.03 AU that are embedded in and get convected past the Earth by high-speed solar wind streams plays a critical and necessary role in the occurrence of upstream ion events near the Earth. C1 [Desai, M. I.] SW Res Inst, Space Sci & Engn, San Antonio, TX USA. [Mason, G. M.] Johns Hopkins Univ, Appl Phys Lab, Laurel, MD USA. [Mueller-Mellin, R.] Univ Kiel, Inst Expt & Angew Phys, Kiel, Germany. [Korth, A.; Mall, U.] Max Planck Inst Solar Syst Res, Katlenburg Lindau, Germany. [Dwyer, J. R.] Florida Inst Technol, Dept Phys & Space Sci, Melbourne, FL 32901 USA. [von Rosenvinge, T. T.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Desai, MI (reprint author), SW Res Inst, Space Sci & Engn, San Antonio, TX USA. NR 47 TC 13 Z9 13 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 AUG 5 PY 2008 VL 113 IS A8 AR A08103 DI 10.1029/2007JA012909 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 336CK UT WOS:000258341700001 ER PT J AU Wu, DL Pickett, HM Livesey, NJ AF Wu, D. L. Pickett, H. M. Livesey, N. J. TI Aura MLS THz observations of global cirrus near the tropopause SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID CLOUD ICE MEASUREMENTS; RADIATIVE-TRANSFER; TROPICAL CIRRUS; EOS MLS AB [1] The first global cirrus observation from spaceborne THz (terahertz) sensors is presented. The 2.5 THz channels of the Microwave Limb Sounder (MLS) instrument on NASA's Aura satellite, measuring atmospheric thermal emission at the limb, has sensitivity to cloud ice particle scattering above similar to 15 km. The magnitude of cloud-induced radiance (T-cir), as high as 40 K, is observed in the THz radiances at the lowermost tangent heights of limb viewing. A special algorithm is developed to extract the THz Tcir by averaging the data spectrally and vertically, removing systematic error in the radiances, and screening cloudy radiances from clear-sky variability. The derived THz Tcir has typical precision of 1.5 - 1.7 K, and a threshold of similar to 6 K is used to determine significant cloud measurements. Monthly maps show that morphologies of the THz Tcir are generally consistent with those of cloud IWC (ice water content) at 121 hPa retrieved simultaneously from the MLS 240 GHz channel. However, the spatial distribution of THz clouds often spreads more broadly in latitude than the GHz clouds, as expected for the better sensitivity of the THz channels to small ice particle scattering. The THz Tcir can be converted to a partial ice water path (pIWP) above similar to 15 km, and the estimated 0.7 g/m 2/K sensitivity for THz Tcir is consistent with the radiative transfer model calculation and MLS 240 GHz measurements. C1 [Wu, D. L.; Pickett, H. M.; Livesey, N. J.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 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 Wu, Dong/D-5375-2012 NR 16 TC 6 Z9 9 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 AUG 2 PY 2008 VL 35 IS 15 AR L15803 DI 10.1029/2008GL034233 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 333JY UT WOS:000258150000003 ER PT J AU Foster, G Annan, JD Schmidt, GA Mann, ME AF Foster, Grant Annan, James D. Schmidt, Gavin A. Mann, Michael E. TI Comment on "Heat capacity, time constant, and sensitivity of Earth's climate system'' by S. E. Schwartz SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Editorial Material ID SERIES; NOISE C1 [Foster, Grant] Isl Data Corp, Carlsbad, CA 92008 USA. [Annan, James D.] JAMSTEC, Frontier Res Ctr Global Change, Kanazawa Ku, Yokohama, Kanagawa 2360001, Japan. [Mann, Michael E.] Penn State Univ, Dept Meteorol, University Pk, PA 16802 USA. [Mann, Michael E.] Penn State Univ, Ctr Earth Syst Sci, University Pk, PA 16802 USA. [Schmidt, Gavin A.] NASA, Goddard Inst Space Studies, New York, NY 10025 USA. RP Foster, G (reprint author), Isl Data Corp, 2386 Faraday Ave,Suite 280, Carlsbad, CA 92008 USA. EM grant.foster@islanddata.com; jdannan@jamstec.go.jp; gschmidt@giss.nasa.gov; mann@psu.edu RI Schmidt, Gavin/D-4427-2012; Annan, James/A-3702-2010; Mann, Michael/B-8472-2017 OI Schmidt, Gavin/0000-0002-2258-0486; Mann, Michael/0000-0003-3067-296X NR 20 TC 18 Z9 19 U1 2 U2 4 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 AUG 2 PY 2008 VL 113 IS D15 AR D15102 DI 10.1029/2007JD009373 PG 5 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 333KN UT WOS:000258151500001 ER PT J AU Fu, TM Jacob, DJ Wittrock, F Burrows, JP Vrekoussis, M Henze, DK AF Fu, Tzung-May Jacob, Daniel J. Wittrock, Folkard Burrows, John P. Vrekoussis, Mihalis Henze, Daven K. TI Global budgets of atmospheric glyoxal and methylglyoxal, and implications for formation of secondary organic aerosols SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Review ID PHASE TROPOSPHERIC CHEMISTRY; BIOMASS-BURNING EMISSIONS; OH-INITIATED OXIDATION; AIR-SEA EXCHANGE; CARBONYL-COMPOUNDS; GAS-PHASE; AROMATIC-HYDROCARBONS; OLIGOMER FORMATION; UNITED-STATES; CHEMICAL MECHANISM AB We construct global budgets of atmospheric glyoxal and methylglyoxal with the goal of quantifying their potential for global secondary organic aerosol (SOA) formation via irreversible uptake by aqueous aerosols and clouds. We conduct a detailed simulation of glyoxal and methylglyoxal in the GEOS-Chem global 3-D chemical transport model including our best knowledge of source and sink processes. Our resulting best estimates of the global sources of glyoxal and methylglyoxal are 45 Tg a(-1) and 140 Tg a(-1), respectively. Oxidation of biogenic isoprene contributes globally 47% of glyoxal and 79% of methylglyoxal. The second most important precursors are acetylene (mostly anthropogenic) for glyoxal and acetone (mostly biogenic) for methylglyoxal. Both acetylene and acetone have long lifetimes and provide a source of dicarbonyls in the free troposphere. Atmospheric lifetimes of glyoxal and methylglyoxal in the model are 2.9 h and 1.6 h, respectively, mostly determined by photolysis. Simulated dicarbonyl concentrations in continental surface air at northern midlatitudes are in the range 10-100 ppt, consistent with in situ measurements. On a global scale, the highest concentrations are over biomass burning regions, in agreement with glyoxal column observations from the SCIAMACHY satellite instrument. SCIAMACHY and a few ship cruises also suggest a large marine source of dicarbonyls missing from our model. The global source of SOA from the irreversible uptake of dicarbonyls in GEOS-Chem is 11 Tg C a(-1), including 2.6 Tg C a(-1) from glyoxal and 8 Tg C a(-1) from methylglyoxal; 90% of this source takes place in clouds. The magnitude of the global SOA source from dicarbonyls is comparable to that computed in GEOS-Chem from the standard mechanism involving reversible partitioning of semivolatile products from the oxidation of monoterpenes, sesquiterpenes, isoprene, and aromatics. C1 [Wittrock, Folkard; Burrows, John P.; Vrekoussis, Mihalis] Univ Bremen, Inst Environm Phys & Remote Sensing, D-28334 Bremen, Germany. [Henze, Daven K.] Columbia Univ, Earth Inst, New York, NY 10025 USA. [Henze, Daven K.] Columbia Univ, NASA, Goddard Inst Space Studies, New York, NY 10025 USA. [Fu, Tzung-May; Jacob, Daniel J.] Harvard Univ, Dept Earth & Planetary Sci, Cambridge, MA 02138 USA. RP Fu, TM (reprint author), Hong Kong Polytech Univ, Dept Civil & Struct Engn, Kowloon, Hong Kong, Peoples R China. EM cetmfu@polyu.edu.hk RI Wittrock, Folkard/B-6959-2008; Henze, Daven/A-1920-2012; Chem, GEOS/C-5595-2014; Fu, Tzung-May/N-3418-2015; Vrekoussis, Mihalis/G-9424-2012; Burrows, John/B-6199-2014 OI Wittrock, Folkard/0000-0002-3024-0211; Vrekoussis, Mihalis/0000-0001-8292-8352; Burrows, John/0000-0002-6821-5580 NR 129 TC 232 Z9 234 U1 15 U2 158 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 AUG 2 PY 2008 VL 113 IS D15 AR D15303 DI 10.1029/2007JD009505 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 333KN UT WOS:000258151500003 ER PT J AU Lopez, JP Luo, M Christensen, LE Loewenstein, M Jost, H Webster, CR Osterman, G AF Lopez, Jimena P. Luo, Ming Christensen, Lance E. Loewenstein, Max Jost, Hansjuerg Webster, Christopher R. Osterman, Greg TI TES carbon monoxide validation during two AVE campaigns using the Argus and ALIAS instruments on NASA's WB-57F SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID TROPOSPHERIC EMISSION SPECTROMETER; CHEMISTRY; N2O; CH4 AB [1] The Aura Validation Experiment (AVE) focuses on validating Aura satellite measurements of important atmospheric trace gases using ground-based, aircraft, and balloon-borne instruments. Global satellite observations of CO from the Tropospheric Emission Spectrometer (TES) on the EOS Aura satellite have been ongoing since September 2004. This paper discusses CO validation experiments during the Oct-AVE (2004 Houston, Texas) and CR-AVE (2006 San Jose, Costa Rica) campaigns. The coincidences in location and time between the satellite observations and the available in situ profiles for some cases are not ideal. However, the CO distribution patterns in the two validation flight areas are shown to have very little variability in the aircraft and satellite observations, thereby making them suitable for validation comparisons. TES CO profiles, which typically have a retrieval uncertainty of 10-20%, are compared with in situ CO measurements from NASA Ames Research Center's Argus instrument taken on board the WB-57F aircraft during Oct-AVE. TES CO retrievals during CR-AVE are compared with in situ measurements from Jet Propulsion Laboratory's Aircraft Laser Infrared Absorption Spectrometer (ALIAS) instrument as well as with the Argus instrument, both taken on board the WB-57F aircraft. During CR-AVE, the average overall difference between ALIAS and Argus CO was 4%, with the ALIAS measurement higher. During individual flights, 2-min time-averaged differences between the two in situ instruments had standard deviation of 14%. The TES averaging kernels and a priori constraint profiles for CO are applied to the in situ data for proper comparisons to account for the reduced vertical resolution and the influence of the a priori in the satellite-derived profile. In the TES sensitive pressure range, similar to 700-200 hPa, the in situ profiles and TES profiles agree within 5-10%, less than the variability in CO distributions obtained by both TES and the aircraft instruments in the two regions. TES CO is slightly lower than in situ measurements in the Houston area (midlatitudes) and slightly higher than in situ CO measurements in the Costa Rica region (tropical). C1 [Lopez, Jimena P.; Loewenstein, Max] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. [Jost, Hansjuerg] Novawave Technol, Redwood City, CA 94065 USA. [Luo, Ming; Christensen, Lance E.; Webster, Christopher R.; Osterman, Greg] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Lopez, Jimena P.] Bay Area Environm Res Inst, Sonoma, CA USA. RP Lopez, JP (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. EM jimena.d.lopez@nasa.gov NR 23 TC 33 Z9 33 U1 0 U2 2 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 AUG 2 PY 2008 VL 113 IS D16 AR D16S47 DI 10.1029/2007JD008811 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 333KS UT WOS:000258152000001 ER PT J AU Booth-Morrison, C Weninger, J Sudbrack, CK Mao, Z Noebe, RD Seidman, DN AF Booth-Morrison, Christopher Weninger, Jessica Sudbrack, Chantal K. Mao, Zugang Noebe, Ronald D. Seidman, David N. TI Effects of solute concentrations on kinetic pathways in Ni-Al-Cr alloys SO ACTA MATERIALIA LA English DT Article DE nickel-based superalloys; atom-probe tomography; temporal evolution; nanostructures ID 3-DIMENSIONAL ATOM-PROBE; FIELD-ION MICROSCOPY; OSTWALD RIPENING THEORIES; NICKEL-BASE SUPERALLOYS; TEMPORAL EVOLUTION; MULTICOMPONENT ALLOYS; RHENIUM ADDITION; PHASE-SEPARATION; VOLUME FRACTION; NUMBER DENSITY AB The kinetic pathways resulting from the formation of coherent gamma'-precipitates from the gamma-matrix are studied for two Ni-Al-Cr alloys with similar gamma'-precipitate volume fractions at 873 K. The details of the phase decompositions of Ni-7.5Al-8.5Cr at.% and Ni-5.2Al-14.2Cr at.% for aging times from 1/6 to 1024 h are investigated by atom-probe tomography, and are found to differ significantly from a mean-field description of coarsening. The morphologies of the gamma'-precipitates of the alloys are similar, though the degrees of gamma'-precipitate coagulation and coalescence differ. Quantification within the framework of classical nucleation theory reveals that differences in the chemical driving forces for phase decomposition result in differences in the nucleation behavior of the two alloys. The temporal evolution of the gamma'-precipitate average radii and the gamma-matrix supersaturations follow the predictions of classical coarsening models. The compositional trajectories of the gamma-matrix phases of the alloys are found to follow approximately the equilibrium tie-lines, while the trajectories of the gamma'-precipitates do not, resulting in significant differences in the partitioning ratios of the solute elements. (c) 2008 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. C1 [Booth-Morrison, Christopher; Weninger, Jessica; Sudbrack, Chantal K.; Mao, Zugang; Seidman, David N.] Northwestern Univ, Dept Mat Sci & Engn, Evanston, IL 60208 USA. [Noebe, Ronald D.] NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. [Seidman, David N.] NUCAPT, Evanston, IL 60208 USA. RP Seidman, DN (reprint author), Northwestern Univ, Dept Mat Sci & Engn, 2220 Campus Dr, Evanston, IL 60208 USA. EM d-seidman@northwestern.edu RI Seidman, David/B-6697-2009 FU National Science Foundation (NSF) [DMR-0241928]; Le Fonds quebecois de la recherche sur la nature et les technologies (FQRNT); NSF; NSF REU; NSF-MRI [DMR 0420532]; ONR-DURIP [N00014-0400798]; NUANCE Center at Northwestern University; NSF-NSEC; NSF-MRSEC; Keck Foundation; State of Illinois; Northwestern University FX This research was sponsored by the National Science Foundation (NSF) under grant DMR-0241928. C.B.M. and C.K.S. received partial support from Le Fonds quebecois de la recherche sur la nature et les technologies (FQRNT) and NSF graduate research fellowships, respectively. J.W. was supported by an NSF REU award when she was an undergraduate at Northwestern University. APT measurements were performed at the Northwestern University Center for Atom-probe Tomography (NUC-APT). The LEAP (TM) tomograph was purchased with funding from the NSF-MRI (DMR 0420532, Dr. Charles Bouldin, grant officer) and ONR-DURIP (N00014-0400798, Dr. Julie Christodoulou, grant officer) programs. Additionally, the LEAP (TM) tomograph was enhanced in April 2006 with a picosecond laser with funding from the ONR-DURIP (N00014-0610539, Dr. Julie Christodoulou, grant officer). The TEM work was performed in the EPIC facility of the NUANCE Center at Northwestern University. The NUANCE Center is supported by NSF-NSEC, NSF-MRSEC, the Keck Foundation, the State of Illinois, and Northwestern University. We extend our gratitude to Dr. Kevin Yoon for his assistance with Thermo-Calc, to Dr. Carelyn Campbell for diffusivity calculations, and to Dr. Georges Martin for discussions. NR 96 TC 33 Z9 33 U1 5 U2 25 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6454 EI 1873-2453 J9 ACTA MATER JI Acta Mater. PD AUG PY 2008 VL 56 IS 14 BP 3422 EP 3438 DI 10.1016/j.actamat.2008.03.016 PG 17 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 345SJ UT WOS:000259016600012 ER PT J AU Mewhinney, M AF Mewhinney, Michael TI Nanotech biosensor helps detect specific biohazards SO ADVANCED MATERIALS & PROCESSES LA English DT News Item C1 NASA, Ames Res Ctr, Moffett Field, CA 94530 USA. RP Mewhinney, M (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94530 USA. EM michael.s.mewhinney@nasa.gov NR 0 TC 0 Z9 0 U1 0 U2 1 PU ASM INT PI MATERIALS PARK PA SUBSCRIPTIONS SPECIALIST CUSTOMER SERVICE, MATERIALS PARK, OH 44073-0002 USA SN 0882-7958 J9 ADV MATER PROCESS JI Adv. Mater. Process. PD AUG PY 2008 VL 166 IS 8 BP 12 EP 13 PG 2 WC Materials Science, Multidisciplinary SC Materials Science GA 337EV UT WOS:000258419200015 ER PT J AU Herring, GC AF Herring, G. C. TI Mach-number measurement with laser and pressure probes in humid supersonic flow SO AIAA JOURNAL LA English DT Article ID INDUCED THERMAL ACOUSTICS; GRATINGS C1 NASA Langley Res Ctr, Hampton, VA 23681 USA. RP Herring, GC (reprint author), NASA Langley Res Ctr, Mail Stop 493, Hampton, VA 23681 USA. EM gregory.c.herring@nasa.gov NR 10 TC 2 Z9 2 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 AUG PY 2008 VL 46 IS 8 BP 2107 EP 2109 DI 10.2514/1.36107 PG 3 WC Engineering, Aerospace SC Engineering GA 335HM UT WOS:000258281400022 ER PT J AU Golden, DC Ming, DW Morris, RV Graff, TG AF Golden, D. C. Ming, D. W. Morris, R. V. Graff, T. G. TI Hydrothermal synthesis of hematite spherules and jarosite: Implications for diagenesis and hematite spherule formation in sulfate outcrops at Meridiani Planum, Mars SO AMERICAN MINERALOGIST LA English DT Article DE hematite; jarosite; spherule; synthesis; diagenesis; Mars; hydrothermal; concretions; thermal emission spectroscopy; X-ray diffraction; Mossbauer spectroscopy; scanning electron microscopy; transmission electron microscopy ID THERMAL EMISSION SPECTROMETER; BURNS FORMATION; CRYSTALLINE HEMATITE; TERRESTRIAL ANALOG; OPPORTUNITY ROVER; ROOM-TEMPERATURE; LANDING SITE; GROWTH; MINERALOGY; SPECTROSCOPY AB We synthesized hematite spherules whose mineralogic, chemical, and crystallographic properties are strikingly similar to those for the hematite-rich spherules in lag deposits oil the surface and embedded ill Outcrops at Meridiani Planum, Mars. The spherules were synthesized in the laboratory along with hydronium jarosite and minor hydronium alunite from Fe-Al-Mg-S-Cl acid-sulfate solutions under hydrothermal conditions. The reaction sequence was (1) precipitation of hydronium jarosite; (2) jarosite dissolution and precipitation of hematite spherules; and (3) precipitation of hydronium alunite upon depletion of hydronium jarosite. The spherules exhibit a radial growth texture with the crystallographic c axis aligned along the radial direction, so that thermal emission spectra have no hematite emissivity minimum at similar to 390 cm(-1). Our experiments show that hydrothermal, acid-sulfate solutions are a pathway for formation of jarosite and the hematite spherules at Meridiani Planum, Mars. C1 [Golden, D. C.] ESCG Hamilton Sundstrand, Houston, TX 77058 USA. [Ming, D. W.; Morris, R. V.] NASA Johnson Space Ctr, Astromat Res & Explorat Sci Directorate, Houston, TX 77058 USA. [Graff, T. G.] Arizona State Univ, Mars Spaceflight Facil, Sch Earth & Space Explorat, Tempe, AZ 85287 USA. RP Golden, DC (reprint author), ESCG Hamilton Sundstrand, Mail Code JE23, Houston, TX 77058 USA. EM douglas.w.ming@nasa.gov FU NASA Mars Fundamental Research Program FX This work was funded by the NASA Mars Fundamental Research Program through a grant to D.W.M. we thank Roy Christofferson of his help in HRTEM imaging, John Gruener and Brad Suffer for assistance with collection and reduction of XRD data, Loan Le for EMPA analysis. and Alan Treiman for samples of the Navajo concretions. We thank the MER Engineering, Operations, and Science Terms for the incredible journey and science return of the Spirit (Gusev, Crater) and Opportunity (Meridiani Planum) rovers. we thank Tim Glotch and Martha Schaefer for detailed reviews. NR 59 TC 42 Z9 42 U1 1 U2 22 PU MINERALOGICAL SOC AMER PI CHANTILLY PA 3635 CONCORDE PKWY STE 500, CHANTILLY, VA 20151-1125 USA SN 0003-004X EI 1945-3027 J9 AM MINERAL JI Am. Miner. PD AUG-SEP PY 2008 VL 93 IS 8-9 BP 1201 EP 1214 DI 10.2138/am.2008.2737 PG 14 WC Geochemistry & Geophysics; Mineralogy SC Geochemistry & Geophysics; Mineralogy GA 339PI UT WOS:000258589100001 ER PT J AU Zolensky, M Gounelle, M Mikouchi, T Ohsumi, K Le, L Hagiya, K Tachikawa, O AF Zolensky, Michael Gounelle, Matthieu Mikouchi, Takashi Ohsumi, Kazumasa Le, Loan Hagiya, Kenji Tachikawa, Osamu TI Andreyivanovite: A second new phosphide from the Kaidun meteorite SO AMERICAN MINERALOGIST LA English DT Article DE andreyivanovite; electron diffraction; phosphide species; Kaidun meteorite ID PATTERNS AB Andreyivanovite (ideally FeCrP) is another new phosphide species from the Kaidun meteorite, which fell in South Yemen in 1980. Kaidun is a unique breccia containing all unprecedented variety of fragments of different chondritic as well as achondritic lithologies. Andreyivanovite was found as individual grains and linear arrays of grains with a maximum dimension of 8 pm within two masses of Fe-rich serpentine. In one sample, it is associated with Fe-Ni-Cr sulfides and florenskyite (FeTiP). Andreyivanovite is creamy white in reflected light, and its luster is metallic. The average of nine electron microprobe analyses yielded the formula Fe(Cr(0.587)Fe(0.150)V(0.109)Ti(0.081)Ni(0.060)Co(0.002))P. Examination of single grains of andreyivanovite using Laue patterns collected by in situ synchrotron X-ray diffraction (XRD), and by electron-backscatter diffraction revealed it to be isostructural with florenskyite; we were unable to Find single crystals of sufficient quality to perform a complete structure analysis. Andreyivanovite crystallizes in the space group Pnma, and has the anti-PbCl(2) structure. Previously determined cell constants of synthetic material [a = 5.833(1), b = 3.569(1), and c = 6.658(1) angstrom] were consistent with our XRD work. We used the XPOW program to calculate a powder-XRD pattern; the 5 most intense reflections are d = 2.247 (I = 100), 2.074 (81), 2.258 (46), 1.785 (43), and 1.885 angstrom (34), Andreyivanovite is the second new phosphide to be described from the Kaidun meteorite. Andreyivanovite could have formed as a result of cooling and crystallization of a melted precursor consisting mainly of Fe-Ni metal enriched in P. Ti, and Cr. Serpentine associated with andreyivanovite would then have formed during aqueous alteration on the parent asteroid. It is also possible that the andreyivanovite Could have formed during aqueous alteration; however, artificial FeTiP has been synthesized only during melting experiments, at low oxygen fugacity, and there is no evidence that a hydrothermal genesis is reasonable. C1 [Zolensky, Michael] NASA Johnson Space Ctr, Houston, TX 77058 USA. [Gounelle, Matthieu] Museum Natl Hist Nat, F-75005 Paris, France. [Mikouchi, Takashi; Tachikawa, Osamu] Univ Tokyo, Dept Earth & Planetary Sci, Bunkyo Ku, Tokyo 113, Japan. [Ohsumi, Kazumasa] Inst Mat Struct Sci, Tsukuba, Ibaraki 305, Japan. [Le, Loan] Jacobs Sverdrup Co, Houston, TX 77058 USA. [Hagiya, Kenji] Univ Hyogo, Grad Sch Life Sci, Kamigori, Hyogo 6781297, Japan. RP Zolensky, M (reprint author), NASA Johnson Space Ctr, Houston, TX 77058 USA. EM michael.e.zolensky@nasa.gov FU NASA [152-11-40-23] FX This study was supported by NASA grant 152-11-40-23 to M.F.Z. Gene Jarosewich provided the phosphide microprobe standard, and Craig Schwandt advised on trickier aspects of the microprobe calibration process. We thank Peter Buseck, Tim McCoy, and Rhian Jones for careful reviews of the manuscript. Masamichi Miyamoto provided the facilities of the Mineralogical Institute, at Tokyo University. at great potential risk to his reputation. NR 12 TC 8 Z9 8 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 AUG-SEP PY 2008 VL 93 IS 8-9 BP 1295 EP 1299 DI 10.2138/am.2008.2614 PG 5 WC Geochemistry & Geophysics; Mineralogy SC Geochemistry & Geophysics; Mineralogy GA 339PI UT WOS:000258589100008 ER PT J AU Kirby, JP Cable, ML Levine, DJ Gray, HB Ponce, A AF Kirby, James P. Cable, Morgan L. Levine, Dana J. Gray, Harry B. Ponce, Adrian TI Spectroscopic analysis of ligand binding to lanthanide-macrocycle platforms SO ANALYTICAL CHEMISTRY LA English DT Article ID BENESI-HILDEBRAND METHOD; CAPILLARY-ELECTROPHORESIS; SENSITIZED LUMINESCENCE; TERBIUM(III) COMPLEXES; INHALATIONAL ANTHRAX; ANION RECOGNITION; SPORE DETECTION; DEVICES; PYRIDINE-2,6-DICARBOXYLATE; PHOTOCHEMISTRY AB A high-affinity, binary Eu3+ receptor site consisting of 1,4,7,10-tetraazacyclododecane-1,7-diacetate (DO2A) was constructed with the goal of improving the detection of dipicolinic acid (DPA), a major component of bacterial spores. Ternary Eu(DO2A)(DPA)(-) complex solutions (1.0 mu M crystallographically characterized TBA.Eu(DO2A)-(DPA)) were titrated with EuCl3 (1.0 nM-1.0 mM); increased Eu3+ concentration resulted in a shift in equilibrium population from Eu(DO2A)(DPA)(-) to Eu(DO2A)(+) and Eu(DPA)(+), which was monitored via the ligand field sensitive D-5(0) -> F-7(3) transition (lambda(em) = 670-700 nm) using luminescence spectroscopy. A best fit of luminescence intensity titration data to a two-state thermodynamic model yielded the competition equilibrium constant (K-c), which in conjunction with independent measurement of the Eu(DPA)(+) formation constant (K-a) allowed calculation of the ternary complex formation constant (K-a'). With this binding affinity by competition (BAC) assay, we determined that K-a' = 1011.21 M-1, which is similar to 1 order of magnitude greater than the formation of Eu(DPA)(+). In general, the BAC assay can be employed to determine ligand binding constants of systems where the lanthanide platform (usually a binary complex) is stable and the ligand bound versus unbound states can be spectroscopically distinguished. C1 [Kirby, James P.; Cable, Morgan L.; Levine, Dana J.; Ponce, Adrian] Jet Prop Lab, Planetary Sci Sect, Pasadena, CA 91109 USA. [Cable, Morgan L.; Levine, Dana J.; Gray, Harry B.; Ponce, Adrian] CALTECH, Beckman Inst, Pasadena, CA 91125 USA. RP Kirby, JP (reprint author), Jet Prop Lab, Planetary Sci Sect, Pasadena, CA 91109 USA. EM james.p.kirby@jpl.nasa.gov; ponce@caltech.edu NR 42 TC 15 Z9 15 U1 4 U2 20 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD AUG 1 PY 2008 VL 80 IS 15 BP 5750 EP 5754 DI 10.1021/ac800154d PG 5 WC Chemistry, Analytical SC Chemistry GA 332PX UT WOS:000258096700016 PM 18578548 ER PT J AU Giles, JW Bankman, IN Sova, RM Morgan, TR Duncan, DD Millard, JA Green, WJ Marcotte, FJ AF Giles, J. W. Bankman, I. N. Sova, R. M. Morgan, T. R. Duncan, D. D. Millard, J. A. Green, W. J. Marcotte, F. J. TI Lidar system model for use with path obscurants and experimental validation SO APPLIED OPTICS LA English DT Article AB When lidar pulses travel through a short path that includes a relatively high concentration of aerosols, scattering phenomena can alter the power and temporal properties of the pulses significantly, causing undesirable effects in the received pulse. In many applications the design of the lidar transmitter and receiver must consider adverse environmental aerosol conditions to ensure the desired performance. We present an analytical model of lidar system operation when the optical path includes aerosols for use in support of instrument design, simulations, and system evaluation. The model considers an optical path terminated with a solid object, although it can also be applied, with minor modifications, to cases where the expected backscatter occurs from nonsolid objects. The optical path aerosols are characterized by their attenuation and backscatter coefficients derived by the Mie theory from the concentration and particle size distribution of the aerosol. Other inputs include the lidar system parameters and instrument response function, and the model output is the time-resolved received pulse. The model is demonstrated and experimentally validated with military fog oil smoke for short ranges (several meters). The results are obtained with a lidar system operating at a wavelength of 0.905 mu m within and outside the aerosol. The model goodness of fit is evaluated using the statistical coefficient of determination whose value ranged from 0.88 to 0.99 in this study. (C) 2008 Optical Society of America. C1 [Giles, J. W.; Bankman, I. N.; Sova, R. M.; Marcotte, F. J.] Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. [Duncan, D. D.] Oregon Hlth & Sci Univ, Dept Biomed Engn, Portland, OR 97239 USA. [Millard, J. A.] Raytheon Missile Syst, Tucson, AZ 85734 USA. [Green, W. J.] NASA, Goddard Space Flight Ctr, Northrop Grumman Tech Serv, Greenbelt, MD 20771 USA. RP Giles, JW (reprint author), Johns Hopkins Univ, Appl Phys Lab, 11100 Johns Hopkins Rd, Laurel, MD 20723 USA. EM john.giles@jhuapl.edu FU The Johns Hopkins University Applied Physics Laboratory FX The authors gratefully acknowledge the Janney Fellowship from The Johns Hopkins University Applied Physics Laboratory for partial support of this effort. NR 16 TC 0 Z9 0 U1 1 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 AUG 1 PY 2008 VL 47 IS 22 BP 4085 EP 4093 DI 10.1364/AO.47.004085 PG 9 WC Optics SC Optics GA 347CT UT WOS:000259118900032 PM 18670566 ER PT J AU Gray, AK Joyce, JJ Wertheimer, AC AF Gray, Andrew K. Joyce, John J. Wertheimer, Alex C. TI Unanticipated departures from breeding designs can be detected using microsatellite DNA parentage analyses SO AQUACULTURE LA English DT Article DE Oncorhynchus tshawytscha; Chinook; microsatellite; parentage analysis; pedigree ID RAINBOW-TROUT; OUTBREEDING DEPRESSION; COMPUTER-PROGRAM; SALMON; POPULATIONS; VARIABILITY; RELATEDNESS; SURVIVAL; MARKERS; GROWTH AB Using microsatellite analysis, a partial pedigree was constructed from an experiment designed to evaluate differences between hatchery Chinook salmon (Oncorhynchus tshawytscha) and their wild donor stocks. First generation (F-1) progeny were created by crossing both hatchery and wild females with hatchery and wild males to create hybrid and control lines. The pedigree analysis revealed an accidental switch of a half-sib control and hybrid F, family. which most likely occurred during incubation and led to the misclassification of individuals in those families. The experimental error propagated into the F-2 lines. The pedigree also revealed a number of unintended full-sib matings in the F-2 crosses. This resulted from the small numbers (5 females, 14 males) of wild fish available for the experiment and differential family survival of the F-1 fish. Because researchers used group-specific physical marks to track typed crosses and not family groups, and because physical marks cannot detect inadvertent movement of fish until they are large enough to mark, experimental error occurred that would have influenced the results had a DNA-based analysis not been employed to verify the integrity of the experiment. Published by Elsevier B.V. C1 [Gray, Andrew K.; Joyce, John J.; Wertheimer, Alex C.] Natl Marine Fisheries Serv, Auke Bay Lab, Juneau, AK 99801 USA. RP Gray, AK (reprint author), Natl Marine Fisheries Serv, Auke Bay Lab, 11305 Glacier Highway, Juneau, AK 99801 USA. EM andrew.gray@noaa.gov NR 19 TC 5 Z9 5 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0044-8486 EI 1873-5622 J9 AQUACULTURE JI Aquaculture PD AUG 1 PY 2008 VL 280 IS 1-4 BP 71 EP 75 DI 10.1016/j.aquaculture.2008.04.021 PG 5 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 344ZG UT WOS:000258965200010 ER PT J AU Marais, DJD Nuth, JA Allamandola, LJ Boss, AP Farmer, JD Hoehler, TM Jakosky, BM Meadows, VS Pohorille, A Runnegar, B Spormann, AM AF Marais, David J. Des Nuth, Joseph A., III Allamandola, Louis J. Boss, Alan P. Farmer, Jack D. Hoehler, Tori M. Jakosky, Bruce M. Meadows, Victoria S. Pohorille, Andrew Runnegar, Bruce Spormann, Alfred M. TI The NASA Astrobiology Roadmap SO ASTROBIOLOGY LA English DT Article AB The NASA Astrobiology Roadmap provides guidance for research and technology development across the NASA enterprises that encompass the space, Earth, and biological sciences. The ongoing development of astrobiology roadmaps embodies the contributions of diverse scientists and technologists from government, universities, and private institutions. The Roadmap addresses three basic questions: how does life begin and evolve, does life exist elsewhere in the universe, and what is the future of life on Earth and beyond? Seven Science Goals outline the following key domains of investigation: understanding the nature and distribution of habitable environments in the universe, exploring for habitable environments and life in our own Solar System, understanding the emergence of life, determining how early life on Earth interacted and evolved with its changing environment, understanding the evolutionary mechanisms and environmental limits of life, determining the principles that will shape life in the future, and recognizing signatures of life on other worlds and on early Earth. For each of these goals, Science Objectives outline more specific high priority efforts for the next three to five years. These eighteen objectives are being integrated with NASA strategic planning. Astrobiology 8, 715-730. C1 [Marais, David J. Des; Allamandola, Louis J.; Hoehler, Tori M.; Pohorille, Andrew] NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. [Nuth, Joseph A., III] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Boss, Alan P.] Carnegie Inst Washington, Dept Terr Magnetism, Washington, DC 20015 USA. [Farmer, Jack D.] Arizona State Univ, Dept Explorat, Tempe, AZ USA. [Jakosky, Bruce M.] Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80309 USA. [Jakosky, Bruce M.] Univ Colorado, Dept Geol Sci, Boulder, CO 80309 USA. [Meadows, Victoria S.] Univ Washington, Dept Astron, Seattle, WA 98195 USA. [Runnegar, Bruce] Univ Calif Los Angeles, Inst Geophys, Los Angeles, CA USA. [Spormann, Alfred M.] Stanford Univ, Dept Civil & Environm Engn, Stanford, CA 94305 USA. RP Marais, DJD (reprint author), NASA, Ames Res Ctr, Div Space Sci, Mail Stop 239-4, Moffett Field, CA 94035 USA. EM David.J.DesMarais@nasa.gov RI Nuth, Joseph/E-7085-2012 NR 0 TC 8 Z9 8 U1 0 U2 19 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 AUG PY 2008 VL 8 IS 4 BP 715 EP 730 DI 10.1089/ast.2008.0819 PG 16 WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology GA 364XN UT WOS:000260369000002 ER PT J AU Schopf, JW Tewari, VC Kudryavtsev, AB AF Schopf, J. William Tewari, Vinod C. Kudryavtsev, Anatoliy B. TI Discovery of a New Chert-Permineralized Microbiota in the Proterozoic Buxa Formation of the Ranjit Window, Sikkim, Northeast India, and Its Astrobiological Implications SO ASTROBIOLOGY LA English DT Article DE Buxa Formation; Ranjit tectonic window; Precambrian microfossils; Mars Sample Return mission; Raman spectroscopy; Confocal laser scanning microscopy ID RAMAN IMAGERY; DISTRICT; HIMALAYA; FOSSILS AB For the foreseeable future, the search for evidence of past life in rocks acquired from other planets will be constrained by the amount of sample available and by the fidelity of preservation of any fossils present. What amount of rock is needed to establish the existence of past life? To address this question, we studied a minute amount of rock collected from cherty dolomites of the Proterozoic Buxa Formation in the metamorphically altered tectonically active northeastern Himalaya. In particular, we investigated 2 small petrographic thin sections-one from each of 2 bedded chert horizons exposed in the Ranjit River stratigraphic section northwest of Rishi, Sikkim, India-that together comprise an area of similar to 5cm(2) ( about the size of a US postage stamp) and have a total rock weight of similar to 0.1 g. Optical microscopy, confocal laser scanning microscopy, and Raman spectroscopy and imagery demonstrate that each of the thin sections contains a rich assemblage of 3-dimensionally permineralized organic-walled microfossils. This study, the first report of Proterozoic microfossils in units of the Ranjit tectonic window, demonstrates that firm evidence of early life can be adduced from even a minuscule amount of fossil-bearing ancient rock. C1 [Schopf, J. William] Univ Calif Los Angeles, Ctr Study Evolut & Origin Life, Inst Geophys & Planetary Sci, Dept Earth & Space Sci,Mol Biol Inst, Los Angeles, CA 90095 USA. [Schopf, J. William; Kudryavtsev, Anatoliy B.] Univ Calif Los Angeles, NASA, Astrobiol Inst, Los Angeles, CA 90095 USA. [Tewari, Vinod C.] Wadia Inst Himalayan Geol, Dehra Dun, Uttarakhand, India. RP Schopf, JW (reprint author), Univ Calif Los Angeles, Ctr Study Evolut & Origin Life, Inst Geophys & Planetary Sci, Dept Earth & Space Sci,Mol Biol Inst, Geol Bldg, Los Angeles, CA 90095 USA. EM Schopf@ess.ucla.edu FU CSEOL; NASA Exobiology [NAG5-12357]; UCLA FX We thank J. Shen-Miller and 2 anonymous reviewers for helpful comments on the manuscript. The research here reported was carried out at the IGPP Center for the Study of Evolution and the Origin of Life (CSEOL) at the University of California, Los Angeles. Optical, CLSM, and Raman studies at UCLA were supported by CSEOL and by NASA Exobiology Grant NAG5-12357 ( to J.W.S.). The participation of A. B. K. was supported by CSEOL and by the UCLA administration in support of UCLA's membership in the NASA Astrobiology Institute. V. C. T. is grateful to CSEOL for providing support for his research visit to UCLA and to Dr. B. R. Arora, Director, Wadia Institute of Himalayan Geology, Dehradun, India, for facilities and permission to publish the paper. NR 16 TC 27 Z9 28 U1 0 U2 8 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 AUG PY 2008 VL 8 IS 4 BP 735 EP 746 DI 10.1089/ast.2007.0184 PG 12 WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology GA 364XN UT WOS:000260369000004 PM 18844456 ER PT J AU Hudson, RL Moore, MH Dworkin, JP Martin, MP Pozun, ZD AF Hudson, Reggie L. Moore, Marla H. Dworkin, Jason P. Martin, Mildred P. Pozun, Zachary D. TI Amino Acids from Ion-Irradiated Nitrile-Containing Ices SO ASTROBIOLOGY LA English DT Article DE Amino acids; Ices; Prebiotic chemistry; Radiation chemistry; Infrared spectra ID INFRARED-SPECTRA; SOLID-STATE; HALE-BOPP; WATER-ICE; ANALOGS; RADIOLYSIS; RELEVANT; MATRIX; COMETS; ACETONITRILE AB Solid CH3CN and solid H2O + CH3CN were ion irradiated near 10 K to initiate chemical reactions thought to occur in extraterrestrial ices. The infrared spectra of these samples after irradiation revealed the synthesis of new molecules. After the irradiated ices were warmed to remove volatiles, the resulting residual material was extracted and analyzed. Both unhydrolyzed and acid-hydrolyzed residues were examined by both liquid and gas chromatographic-mass spectral methods and found to contain a rich mixture of products. The unhydrolyzed samples showed HCN, NH3, acetaldehyde (formed by reaction with background and atmospheric H2O), alkyamines, and numerous other compounds, but no amino acids. However, reaction products in hydrolyzed residues contained a suite of amino acids that included some found in carbonaceous chondrite meteorites. Equal amounts of D- and L-enantiomers were found for each chiral amino acid detected. Extensive use was made of C-13-labeled CH3CN to confirm amino acid identifications and discriminate against possible terrestrial contaminants. The results reported here show that ices exposed to cosmic rays can yield products that, after hydrolysis, form a set of primary amino acids equal in richness to those made by other methods, such as photochemistry. C1 [Hudson, Reggie L.] Eckerd Coll, Dept Chem, St Petersburg, FL 33711 USA. [Hudson, Reggie L.; Moore, Marla H.; Dworkin, Jason P.; Martin, Mildred P.; Pozun, Zachary D.] NASA, Goddard Ctr Astrobiol, Astrobiol Inst, Greenbelt, MD USA. [Moore, Marla H.; Dworkin, Jason P.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Martin, Mildred P.] Catholic Univ Amer, Washington, DC 20064 USA. [Pozun, Zachary D.] Univ Pittsburgh, Pittsburgh, PA USA. RP Hudson, RL (reprint author), Eckerd Coll, Dept Chem, 4200 54th Ave South, St Petersburg, FL 33711 USA. EM hudsonrl@eckerd.edu RI Pozun, Zachary/K-7659-2012; Dworkin, Jason/C-9417-2012; Hudson, Reggie/E-2335-2012 OI Pozun, Zachary/0000-0002-8201-7329; Dworkin, Jason/0000-0002-3961-8997; FU NASA funding through the Goddard Center FX NASA funding through the Goddard Center for Astrobiology and Planetary Atmospheres is acknowledged. R. L. H. also acknowledges the support NR 35 TC 29 Z9 30 U1 4 U2 26 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 AUG PY 2008 VL 8 IS 4 BP 771 EP 779 DI 10.1089/ast.2007.0131 PG 9 WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology GA 364XN UT WOS:000260369000006 PM 18752457 ER PT J AU Seshadri, S Chin, KB Buehler, MG Anderson, RC AF Seshadri, Suresh Chin, Keith B. Buehler, Martin G. Anderson, Robert C. TI Using Electrical Impedance Spectroscopy to Detect Water in Planetary Regoliths SO ASTROBIOLOGY LA English DT Article DE Liquid water; Ice; Salts; In situ measurement; Planetary instrumentation ID MARS; ICE; SURFACE; HYDROGEN; STATE; FROST AB We present data in examination of the utility of electrical impedance spectroscopy measurements for in situ surveys to determine the water content, distribution, and phase in unconsolidated planetary regolith. We conducted calibration experiments under conditions relevant to Mars: the concentration of electrolytes in solution was varied up to 1 M to simulate the effects of unsaturated dissolved minerals and brines. We also varied the water content of heterogeneous water/sand mixtures, made with these electrolytic solutions from 0.01 wt% to 10 wt%. Tests were performed at temperatures from +25 degrees C to -65 degrees C. Conductivity and dielectric permittivity calculated from the impedance measurements indicate an expected dependence on electrolyte concentration and relative independence from electrolyte type for both liquid water and water ice. Conductivity and calculated dielectric relaxation times for these aqueous solutions agree with existing data in the literature. The relative permittivity for heterogeneous water/sand mixtures is dominated by polarization effects for the electrode configuration used. However, the characteristic orientational relaxation of ice is still visible. The conductivity retains the strong dependence on electrolyte concentration, and the permittivity is still not affected by electrolyte type. A "universal" curve between conductivity and water content establishes detectability limits of <0.01 wt% and similar to 0.3 wt% for water/sand mixtures containing liquid water and ice, respectively. C1 [Seshadri, Suresh; Chin, Keith B.; Anderson, Robert C.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Buehler, Martin G.] Decagon Devices Inc, Pullman, WA USA. RP Seshadri, S (reprint author), CALTECH, Jet Prop Lab, MS 300-315,4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM suresh.seshadri@jpl.nasa.gov FU NASA Astrobiology Science & Technology Instrument Development (ASTID); ECP Construction & Resource Utilization eXploror (CRUX) FX The work described in this paper was performed by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. This effort was supported by the NASA Astrobiology Science & Technology Instrument Development (ASTID) and ECP Construction & Resource Utilization eXploror (CRUX) programs. NR 35 TC 6 Z9 6 U1 2 U2 9 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 AUG PY 2008 VL 8 IS 4 BP 781 EP 792 DI 10.1089/ast.2007.0180 PG 12 WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology GA 364XN UT WOS:000260369000007 PM 18752458 ER PT J AU Mitrofanov, IG Sanin, AB Golovin, DV Litvak, ML Konovalov, AA Kozyrev, AS Malakhov, AV Mokrousov, MI Tretyakov, VI Troshin, VS Uvarov, VN Varenikov, AB Vostrukhin, AA Shevchenko, VV Shvetsov, VN Krylov, AR Timoshenko, GN Bobrovnitsky, YI Tomilina, TM Grebennikov, AS Kazakov, LL Sagdeev, RZ Milikh, GN Bartels, A Chin, G Floyd, S Garvin, J Keller, J McClanahan, T Trombka, J Boynton, W Harshman, K Starr, R Evans, L AF Mitrofanov, I. G. Sanin, A. B. Golovin, D. V. Litvak, M. L. Konovalov, A. A. Kozyrev, A. S. Malakhov, A. V. Mokrousov, M. I. Tretyakov, V. I. Troshin, V. S. Uvarov, V. N. Varenikov, A. B. Vostrukhin, A. A. Shevchenko, V. V. Shvetsov, V. N. Krylov, A. R. Timoshenko, G. N. Bobrovnitsky, Y. I. Tomilina, T. M. Grebennikov, A. S. Kazakov, L. L. Sagdeev, R. Z. Milikh, G. N. Bartels, A. Chin, G. Floyd, S. Garvin, J. Keller, J. McClanahan, T. Trombka, J. Boynton, W. Harshman, K. Starr, R. Evans, L. TI Experiment LEND of the NASA Lunar Reconnaissance Orbiter for High-Resolution Mapping of Neutron Emission of the Moon SO ASTROBIOLOGY LA English DT Editorial Material DE Moon; Neutron radiation; Hydrogen abundance; Polar cold traps ID POLAR HYDROGEN DEPOSITS; MARS ODYSSEY; INSTRUMENT SUITE; WATER-ICE; SURFACE AB The scientific objectives of neutron mapping of the Moon are presented as 3 investigation tasks of NASA's Lunar Reconnaissance Orbiter mission. Two tasks focus on mapping hydrogen content over the entire Moon and on testing the presence of water-ice deposits at the bottom of permanently shadowed craters at the lunar poles. The third task corresponds to the determination of neutron contribution to the total radiation dose at an altitude of 50 km above the Moon. We show that the Lunar Exploration Neutron Detector ( LEND) will be capable of carrying out all 3 investigations. The design concept of LEND is presented together with results of numerical simulations of the instrument's sensitivity for hydrogen detection. The sensitivity of LEND is shown to be characterized by a hydrogen detection limit of about 100 ppm for a polar reference area with a radius of 5 km. If the presence of ice deposits in polar "cold traps" is confirmed, a unique record of many millions of years of lunar history would be obtained, by which the history of lunar impacts could be discerned from the layers of water ice and dust. Future applications of a LEND-type instrument for Mars orbital observations are also discussed. C1 [Mitrofanov, I. G.; Sanin, A. B.; Golovin, D. V.; Litvak, M. L.; Konovalov, A. A.; Kozyrev, A. S.; Malakhov, A. V.; Mokrousov, M. I.; Tretyakov, V. I.; Troshin, V. S.; Uvarov, V. N.; Varenikov, A. B.; Vostrukhin, A. A.] Russian Acad Sci, Inst Space Res, Moscow 117997, Russia. [Shevchenko, V. V.] Moscow MV Lomonosov State Univ, Sternberg Astron Inst, Moscow, Russia. [Shvetsov, V. N.; Krylov, A. R.; Timoshenko, G. N.] Joint Inst Nucl Energy, Moscow, Russia. [Bobrovnitsky, Y. I.; Tomilina, T. M.; Grebennikov, A. S.] AA Blagonravov Mech Engn Inst, Moscow, Russia. [Kazakov, L. L.] Inst Phys Nucl Reactors, Dmitrovograd, Russia. [Sagdeev, R. Z.; Milikh, G. N.] Univ Maryland, College Pk, MD 20742 USA. [Bartels, A.; Chin, G.; Floyd, S.; Garvin, J.; Keller, J.; McClanahan, T.; Trombka, J.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Boynton, W.; Harshman, K.] Univ Arizona, Tucson, AZ USA. [Starr, R.] Catholic Univ, Washington, DC USA. [Evans, L.] Comp Sci Corp, Greenbelt, MD USA. RP Mitrofanov, IG (reprint author), Russian Acad Sci, Inst Space Res, Profsojuznaja 84-32, Moscow 117997, Russia. EM mitrofanov@1503.iki.rssi.ru RI McClanahan, Timothy/C-8164-2012; Chin, Gordon/E-1520-2012; Keller, John/I-5097-2013 NR 24 TC 24 Z9 24 U1 0 U2 8 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 AUG PY 2008 VL 8 IS 4 BP 793 EP 804 DI 10.1089/ast.2007.0158 PG 12 WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology GA 364XN UT WOS:000260369000008 PM 18844457 ER PT J AU Nadeau, JL Perreault, NN Niederberger, TD Whyte, LG Sun, HJ Leon, R AF Nadeau, J. L. Perreault, N. N. Niederberger, T. D. Whyte, L. G. Sun, H. J. Leon, R. TI Fluorescence Microscopy as a Tool for In Situ Life Detection SO ASTROBIOLOGY LA English DT Article DE Fluorescence microscopy; Dyes; Quantum dots; Biosignatures; Wet chemistry ID AXEL-HEIBERG ISLAND; QUANTUM DOTS; EXPEDITION FJORD; NATURAL HABITATS; SOIL BACTERIA; MICROORGANISMS; MARS; PANSPERMIA; ENUMERATION; EXPLORATION AB The identification of extant and, in some cases, extinct bacterial life is most convincingly and efficiently performed with modern high-resolution microscopy. Epifluorescence microscopy of microbial autofluorescence or in conjunction with fluorescent dyes is among the most useful of these techniques. We explored fluorescent labeling and imaging of bacteria in rock and soil in the context of in situ life detection for planetary exploration. The goals were two-fold: to target non-Earth-centric biosignatures with the greatest possible sensitivity and to develop labeling procedures amenable to robotic implementation with technologies that are currently space qualified. A wide panel of commercially available dyes that target specific biosignature molecules was screened, and those with desirable properties (i.e., minimal binding to minerals, strong autofluorescence contrast, no need for wash steps) were identified. We also explored the potential of semiconductor quantum dots (QDs) as bacterial and space probes. A specific instrument for space implementation is suggested and discussed. C1 [Nadeau, J. L.] McGill Univ, Dept Biomed Engn, Montreal, PQ H3A 2B4, Canada. [Perreault, N. N.; Niederberger, T. D.; Whyte, L. G.] McGill Univ, Dept Nat Resource Sci, Montreal, PQ H3A 2B4, Canada. [Sun, H. J.] Desert Res Inst, Div Earth & Ecosyst Sci, Las Vegas, NV USA. [Leon, R.] CALTECH, Jet Prop Lab, Pasadena, CA USA. RP Nadeau, JL (reprint author), McGill Univ, Dept Biomed Engn, Montreal, PQ H3A 2B4, Canada. EM jay.nadeau@mcgill.ca FU U.S. EPA-Science [R831712]; National Science and Engineering Research Council of Canada (NSERC) [RGPIN 312970]; Canadian Space Agency (CSA) Canadian Analogue Research Network (CARN); Canadian Polar Continental Shelf Project; McGill University's High Arctic Research Station; Department of Indian; Northern Affairs-Northern Scientific Training Program; Fonds Quebecois de la Recherche sur la Nature et les Technologies (FQRNT) FX J.L.N. acknowledges support from the U.S. EPA-Science to Achieve Results (STAR) program Grant #R831712 and by the National Science and Engineering Research Council of Canada (NSERC) Grant #RGPIN 312970. Field work on Axel Heiberg for J.L.N. and L. G. W. was supported by the Canadian Space Agency (CSA) Canadian Analogue Research Network (CARN) program. Logistical support was provided by the Canadian Polar Continental Shelf Project and McGill University's High Arctic Research Station. L. G. W. acknowledges support from the Natural Sciences and Engineering Research Council of Canada (NSERC). Additional funding for NP was provided by the Department of Indian and Northern Affairs-Northern Scientific Training Program and the Fonds Quebecois de la Recherche sur la Nature et les Technologies (FQRNT). NR 54 TC 26 Z9 26 U1 2 U2 17 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 AUG PY 2008 VL 8 IS 4 BP 859 EP 875 DI 10.1089/ast.2007.0043 PG 17 WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology GA 364XN UT WOS:000260369000013 PM 18752456 ER PT J AU Velusamy, T Langer, WD AF Velusamy, T. Langer, William D. TI Polycyclic aromatic hydrocarbon and H(2) emissions in the ultraviolet-dominated region in NGC 2316 SO ASTRONOMICAL JOURNAL LA English DT Article DE dust, extinction; infrared : ISM; ISM : clouds; ISM : individual (NGC 2316, Parsamyan 18, L1654); ISM : molecules ID INFRARED-EMISSION; PHOTODISSOCIATION REGIONS; REFLECTION NEBULAE; LINE EMISSION; BENDING MODES; SMALL GRAINS; FEATURES; SPECTRUM; SPECTROSCOPY; EXCITATION AB NGC 2316 is a young star cluster embedded in a dense cloud containing a central H II region powered by a B3 star. The ultraviolet (UV) radiation emitted by this young star affects the physical conditions and the chemical composition of the surrounding cloud. We present Spitzer Infrared Spectrograph (IRS) spectral maps of the polycyclic aromatic hydrocarbon (PAH) features and H(2) lines in the 9-14 mu m(SL1) and 15-20 mu m(LL2) bands obtained using multiple slit positions. We show the distribution of 7.7 mu m, 8.6 mu m, 10-14 mu m, 16-18 mu m, and 19.0 mu m PAH bands and the spatial variations among the bright narrow PAH features at 11.2, 12.0, 12.7, 16.4, 17.4, and 17.7 mu m with distance from the ultraviolet (UV) source. We show that the Infrared Array Camera (IRAC) 8 mu m emission is primarily due to the 7.7 and 8.6 mu m PAH features. The IRAC 8 mu m image of the entire cloud containing the cluster and the B3 star shows PAH emission on a large scale, not covered by IRS spectral data. We have also mapped the line intensities of three pure rotational H(2) transitions: 0-0 S(1) Ortho 17.0 mu m, 0-0 S(2) Para 12.3 mu m, and 0-0 S(3) Ortho 9.7 mu m. We detect a limb-brightened shell of H(2) line emission at 15 '' radius from the star. This H(2) line emission in NGC 2316 is consistent with UV-pumped fluorescence in an H(2) production zone. The correlation between the H(2) and PAH emissions in the H(2) shell suggest efficient formation of H(2) by chemisorption on PAH surfaces. The intensities of all PAH features increase toward the UV source, but their relative contributions to the overall band emissions differ with the distance from the UV source. The detection of PAH emissions closest to the UV source implies the survival of PAHs in the intense, but softer UV radiation field of the B3 star. Using the radial intensities and a phenomenological model for PAH destruction as a function of distance from the UV source, we estimate the relative survival of the emitters (PAH components) in each spectrally resolved PAH emission feature. We identify four distinct PAH emission zones in NGC 2316 with a central UV source embedded in nearly spherical dense cloud with an average A(upsilon) similar to 4.5 mag. Their emission characteristics and variations add new constraints to the PAH composition and excitation modes. C1 [Velusamy, T.; Langer, William D.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Velusamy, T (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM velusamy@jpl.nasa.gov NR 45 TC 10 Z9 10 U1 0 U2 3 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 AUG PY 2008 VL 136 IS 2 BP 602 EP 613 DI 10.1088/0004-6256/136/2/602 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 326SU UT WOS:000257680000008 ER PT J AU Butters, OW Norton, AJ Hakala, P Mukai, K Barlow, EJ AF Butters, O. W. Norton, A. J. Hakala, P. Mukai, K. Barlow, E. J. TI RXTE determination of the intermediate polar status of XSS J00564+4548, IGR J17195-4100, and XSS J12270-4859 SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE binaries : close; stars : novae, cataclysmic variables; X-rays : binaries ID X-RAY SOURCES; CATACLYSMIC VARIABLES; GALACTIC PLANE; SURVEY CATALOG AB Aims. We determine the nature of the intermediate polar candidates XSS J00564+4548, IGR J17195-4100, and XSS J12270-4859. Methods. Pointed RXTE observations searched for intermediate polar characteristics in these candidate systems. Results. XSS J00564+4548 exhibits a period of 465.68 +/- 0.07 s, which we interpret as the spin period, an energy dependent modulation depth, and a spectrum that is fit by a 22 keV photoelectrically absorbed bremsstrahlung with an iron line profile. IGR J17195-4100 shows several candidate periodicities and a spectrum that is fit by a power law with an iron line. XSS J12270-4859 exhibits a candidate spin period of 859.57 +/- 0.64 s and a spectrum that is fit by a power law with no evidence of an iron line. Conclusions. XSS J00564+4548 is confirmed to be an intermediate polar. IGR J17195-4100 and XSS J12270-4859 both show some properties of intermediate polars, but cannot be confirmed as definite members of the class here. C1 [Butters, O. W.; Norton, A. J.; Barlow, E. J.] Open Univ, Dept Phys & Astron, Milton Keynes MK7 6AA, Bucks, England. [Hakala, P.] Univ Turku, Tuorla Observ, Piikkio 21500, Finland. [Mukai, K.] CRESST, Greenbelt, MD 20771 USA. [Mukai, K.] NASA, Goddard Space Flight Ctr, Xray Astrophys Lab, Greenbelt, MD 20771 USA. RP Butters, OW (reprint author), Open Univ, Dept Phys & Astron, Milton Keynes MK7 6AA, Bucks, England. EM o.w.butters@open.ac.uk OI Norton, Andrew/0000-0001-7619-8269; Butters, Olly/0000-0003-0354-8461 NR 18 TC 21 Z9 21 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 AUG PY 2008 VL 487 IS 1 BP 271 EP 276 DI 10.1051/0004-6361:200809942 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 335XI UT WOS:000258327000029 ER PT J AU Goldman, B Cushing, MC Marley, MS Artigau, E Baliyan, KS Bejar, VJS Caballero, JA Chanover, N Connelley, M Doyon, R Forveille, T Ganesh, S Gelino, CR Hammel, HB Holtzman, J Joshi, S Joshi, UC Leggett, SK Liu, MC Martin, EL Mohan, V Nadeau, D Sagar, R Stephens, D AF Goldman, B. Cushing, M. C. Marley, M. S. Artigau, E. Baliyan, K. S. Bejar, V. J. S. Caballero, J. A. Chanover, N. Connelley, M. Doyon, R. Forveille, T. Ganesh, S. Gelino, C. R. Hammel, H. B. Holtzman, J. Joshi, S. Joshi, U. C. Leggett, S. K. Liu, M. C. Martin, E. L. Mohan, V. Nadeau, D. Sagar, R. Stephens, D. TI CLOUDS search for variability in brown dwarf atmospheres - Infrared spectroscopic time series of L/T transition brown dwarfs SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE stars : low-mass, brown dwarfs; stars : atmospheres; techniques : spectroscopic; stars : general ID DIGITAL SKY SURVEY; METHANE T-DWARFS; H-ALPHA EMISSION; L FIELD DWARFS; SPECTRAL CLASSIFICATION; ULTRACOOL DWARFS; PHOTOMETRIC VARIABILITY; SPECTROGRAPH; ABSORPTION; MULTIPLICITY AB Context. L-type ultra-cool dwarfs and brown dwarfs have cloudy atmospheres that could host weather-like phenomena. The detection of photometric or spectral variability would provide insight into unresolved atmospheric heterogeneities, such as holes in a global cloud deck. Indeed, a number of ultra-cool dwarfs have been reported to vary. Additional time-resolved spectral observations of brown dwarfs offer the opportunity for further constraining and characterising atmospheric variability. Aims. It has been proposed that growth of heterogeneities in the global cloud deck may account for the L-to T-type transition when brown dwarf photospheres evolve from cloudy to clear conditions. Such a mechanism is compatible with variability. We searched for variability in the spectra of five L6 to T6 brown dwarfs to test this hypothesis. Methods. We obtained spectroscopic time series using the near-infrared spectrographs ISAAC on VLT-ANTU, over 0.99-1.13 mu m, and SpeX on the Infrared Telescope Facility for two of our targets in the J, H, and K bands. We searched for statistically variable lines and for a correlation between those. Results. High spectral-frequency variations are seen in some objects, but these detections are marginal and need to be confirmed. We find no evidence of large-amplitude variations in spectral morphology and we place firm upper limits of 2 to 3% on broad-band variability, depending on the targets and wavelengths, on the time scale of a few hours. In contrast to the rest of the sample, the T2 transition brown dwarf SDSS J1254-0122 shows numerous variable features, but a secure variability diagnosis would require further observations. Conclusions. Assuming that any variability arises from the rotation of patterns of large-scale clear and cloudy regions across the surface, we find that the typical physical scale of cloud-cover disruption should be smaller than 5-8% of the disk area for four of our targets, using simplistic heterogeneous atmospheric models. The possible variations seen in SDSS J1254-0122 are not strong enough to allow us to confirm the cloud-breaking hypothesis. C1 [Goldman, B.; Chanover, N.; Gelino, C. R.; Holtzman, J.] New Mexico State Univ, Dept Astron, Las Cruces, NM 88003 USA. [Goldman, B.; Caballero, J. A.] MPIA, D-69117 Heidelberg, Germany. [Cushing, M. C.] Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. [Marley, M. S.] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. [Artigau, E.] AURA Inc, So Operat Ctr, Gemini Observ, La Serena 603, Chile. [Baliyan, K. S.; Ganesh, S.; Joshi, U. C.] Phys Res Lab, Astron & Astrophys Div, Ahmadabad 380009, Gujarat, India. [Bejar, V. J. S.] Inst Astrofis Canarias, GTC Project, Tenerife 38025, Spain. [Connelley, M.; Liu, M. C.] Univ Hawaii, Inst Astron, Honolulu, HI 96822 USA. [Doyon, R.; Nadeau, D.] Univ Montreal, Observ Mt Megan, Montreal, PQ H3C 3J7, Canada. [Doyon, R.; Nadeau, D.] Univ Montreal, Dept Phys, Montreal, PQ H3C 3J7, Canada. [Forveille, T.] Canada France Hawaii Telescope Corp, Kamuela, HI 96743 USA. [Forveille, T.] Domaine Univ St Martin Heres, Observ Grenoble, F-38041 Grenoble, France. [Gelino, C. R.] CALTECH, Spitzer Sci Ctr, Pasadena, CA 91125 USA. [Hammel, H. B.] Space Sci Inst, Boulder, CO 80301 USA. [Joshi, S.; Sagar, R.] Aryabhatta Res Inst Observat Sci ARIES, Naini Tal 263129, India. [Leggett, S. K.] Joint Astron Ctr, Hilo, HI 96720 USA. [Mohan, V.] IUCAA, Pune 411007, Maharashtra, India. [Stephens, D.] Brigham Young Univ, Dept Phys & Astron, Provo, UT 84602 USA. RP Goldman, B (reprint author), New Mexico State Univ, Dept Astron, Las Cruces, NM 88003 USA. EM goldman@mpia.de RI Marley, Mark/I-4704-2013; Caballero, Jose/C-2819-2017 OI Caballero, Jose/0000-0002-7349-1387 NR 58 TC 20 Z9 20 U1 1 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 AUG PY 2008 VL 487 IS 1 BP 277 EP 292 DI 10.1051/0004-6361:20065075 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 335XI UT WOS:000258327000030 ER PT J AU Min, M Waters, LBFM de Koter, A Hovenier, JW Keller, LP Markwick-Kemper, F AF Min, M. Waters, L. B. F. M. de Koter, A. Hovenier, J. W. Keller, L. P. Markwick-Kemper, F. TI The shape and composition of interstellar silicate grains (vol 462, pg 667, 2007) SO ASTRONOMY & ASTROPHYSICS LA English DT Correction DE dust; extinction; infrared : ISM; errata; addenda ID INTERPLANETARY DUST; COMETS C1 [Min, M.; Waters, L. B. F. M.; de Koter, A.; Hovenier, J. W.] Univ Amsterdam, Astron Inst Anton Pannekoek, NL-1098 SJ Amsterdam, Netherlands. [Waters, L. B. F. M.] Katholieke Univ Leuven, Inst Sterrenkunde, B-3001 Heverlee, Belgium. [Keller, L. P.] NASA, Johnson Space Ctr, Houston, TX 77058 USA. [Markwick-Kemper, F.] Univ Virginia, Dept Astron, Charlottesville, VA 22904 USA. RP Min, M (reprint author), Univ Amsterdam, Astron Inst Anton Pannekoek, Kruislaan 403, NL-1098 SJ Amsterdam, Netherlands. EM mmin@science.uva.nl NR 10 TC 6 Z9 6 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 AUG PY 2008 VL 486 IS 3 BP 779 EP 780 DI 10.1051/0004-6361:20065436e PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 335XF UT WOS:000258326500019 ER PT J AU Wise, JH Turk, MJ Abel, T AF Wise, John H. Turk, Matthew J. Abel, Tom TI Resolving the formation of protogalaxies. II. Central gravitational collapse SO ASTROPHYSICAL JOURNAL LA English DT Review DE black hole physics; cosmology : theory; galaxies : formation; instabilities ID PROBE WMAP OBSERVATIONS; DWARF SPHEROIDAL GALAXIES; SUPERMASSIVE BLACK-HOLES; BAR-FORMING INSTABILITY; ROTATING STELLAR MODELS; ACTIVE GALACTIC NUCLEI; LAMBDA-CDM UNIVERSE; DARK-MATTER HALOES; X-RAY-CLUSTERS; STAR-FORMATION AB Numerous cosmological hydrodynamic studies have addressed the formation of galaxies. Here we choose to study the first stages of galaxy formation, including nonequilibrium atomic primordial gas cooling, gravity, and hydrodynamics. Using initial conditions appropriate for the concordance cosmological model of structure formation, we perform two adaptive mesh refinement simulations of similar to 10(8)M(circle dot) galaxies at high redshift. The calculations resolve the Jeans length at all times with more than 16 cells and capture over 14 orders of magnitude in length scales. In both cases, the dense, 10(5) solar mass, one parsec central regions are found to contract rapidly and have turbulent Mach numbers up to 4. Despite the ever decreasing Jeans length of the isothermal gas, we only find one site of fragmentation during the collapse. However, rotational secular bar instabilities transport angular momentum outward in the central parsec as the gas continues to collapse and lead to multiple nested unstable fragments with decreasing masses down to sub-Jupiter mass scales. Although these numerical experiments neglect star formation and feedback, they clearly highlight the physics of turbulence in gravitationally collapsing gas. The angular momentum segregation seen in our calculations plays an important role in theories that form supermassive black holes from gaseous collapse. C1 [Wise, John H.; Turk, Matthew J.; Abel, Tom] Stanford Univ, Kavli Inst Particle Astrophys & Cosmol, Menlo Pk, CA 94025 USA. RP Wise, JH (reprint author), NASA, Lab Observat Cosmol, Goddard Space Flight Ctr, Greenbelt, MD 21114 USA. OI Turk, Matthew/0000-0002-5294-0198 NR 123 TC 122 Z9 122 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 AUG 1 PY 2008 VL 682 IS 2 BP 745 EP 757 DI 10.1086/588209 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 331PZ UT WOS:000258026100005 ER PT J AU Bolton, AS Burles, S Koopmans, LVE Treu, T Gavazzi, R Moustakas, LA Wayth, R Schlegel, DJ AF Bolton, Adam S. Burles, Scott Koopmans, Leon V. E. Treu, Tommaso Gavazzi, Raphael Moustakas, Leonidas A. Wayth, Randall Schlegel, David J. TI The Sloan Lens ACS Survey. V. The full ACS strong-lens sample SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : elliptical and lenticular, cD; gravitational lensing; surveys ID DIGITAL SKY SURVEY; EARLY-TYPE GALAXIES; SPECTROSCOPIC TARGET SELECTION; FIELD ELLIPTIC GALAXIES; LUMINOUS RED GALAXY; CLUSTER CL 1358+62; 3RD DATA RELEASE; GRAVITATIONAL LENS; EINSTEIN RING; INTERMEDIATE-REDSHIFT AB We present the definitive data for the full sample of 131 strong gravitational lens candidates observed with the Advanced Camera for Surveys (ACS) aboard the Hubble Space Telescope by the Sloan Lens ACS (SLACS) Survey. All targets were selected for higher redshift emission lines and lower redshift continuum in a single Sloan Digital Sky Survey (SDSS) spectrum. The foreground galaxies are primarily of early-type morphology, with redshifts from z similar or equal to 0.05 to 0.5 and velocity dispersions from sigma similar or equal to 160 to 400 km s(-1); the faint background emission-line galaxies have redshifts ranging from z similar or equal to 0.2 to 1.2. We confirm 70 systems showing clear evidence of multiple imaging of the background galaxy by the foreground galaxy, as well as an additional 19 systems with probable multiple imaging. For 63 clear lensing systems, we present singular isothermal ellipsoid and light-traces-mass gravitational lens models fitted to the ACS imaging data. These strong-lensing mass measurements are supplemented by magnitudes and effective radii measured from ACS surface brightness photometry and redshifts and velocity dispersions measured from SDSS spectroscopy. These data constitute a unique resource for the quantitative study of the interrelations between mass, light, and kinematics in massive early-type galaxies. We show that the SLACS lens sample is statistically consistent with being drawn at random from a parent sample of SDSS galaxies with comparable spectroscopic parameters and effective radii, suggesting that the results of SLACS analyses can be generalized to the massive early-type population. C1 [Bolton, Adam S.; Wayth, Randall] Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. [Burles, Scott] MIT, Dept Phys, Cambridge, MA 02139 USA. [Burles, Scott] MIT, Kavli Inst Astrophys & Space Res, Cambridge, MA 02139 USA. [Koopmans, Leon V. E.] Univ Groningen, Kapteyn Astron Inst, NL-9700 AV Groningen, Netherlands. [Treu, Tommaso; Gavazzi, Raphael] Univ Calif Santa Barbara, Dept Phys, Santa Barbara, CA 93101 USA. [Gavazzi, Raphael] CNRS, Inst Astrophys, UMR7095, F-75014 Paris, France. [Gavazzi, Raphael] Univ Paris 06, F-75014 Paris, France. [Moustakas, Leonidas A.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Schlegel, David J.] Univ Calif Berkeley, Lawrence Berkeley Lab, Div Phys, Berkeley, CA 94720 USA. EM bolton@ifa.hawaii.edu; burles@mit.edu; koopmans@astro.rug.nl; tt@physics.ucsb.edu; gavazzi@iap.fr; leonidas@jpl.nasa.gov; rwayth@cfa.harvard.edu; djschlegel@lbl.gov RI Wayth, Randall/B-2444-2013; OI Wayth, Randall/0000-0002-6995-4131; Moustakas, Leonidas/0000-0003-3030-2360 NR 81 TC 169 Z9 169 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 AUG 1 PY 2008 VL 682 IS 2 BP 964 EP 984 DI 10.1086/589327 PG 21 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 331PZ UT WOS:000258026100022 ER PT J AU Rau, A Ofek, EO Kulkarni, SR Madore, BF Pevunova, O Ajello, M AF Rau, A. Ofek, E. O. Kulkarni, S. R. Madore, B. F. Pevunova, O. Ajello, M. TI A survey for fast transients in the Fornax Cluster of galaxies SO ASTROPHYSICAL JOURNAL LA English DT Article DE delta Scuti; stars : flare; stars : variables : other; surveys ID LUMINOUS SUPERNOVA; MASSIVE STAR; VARIABILITY; SEARCH; DISCOVERY; SN-2006GY; LIMITS; M85 AB The luminosity gap between novae (M-R <= -10) and supernovae (MR >= -14) has been well known since the pioneering research of Zwicky and Hubble. Nearby galaxy clusters and concentrations offer an excellent opportunity to search for explosions brighter than classical novae and fainter than supernovae. Here we present the results of a B-band survey of 23 member galaxies of the Fornax Cluster, performed at the Las Campanas 2.5 m Irenee du Pont telescope. Observations with a cadence of 32 minutes discovered no genuine fast transient to a limiting absolute magnitude of M-B = -9.3 mag. We provide a detailed assessment of the transient detection efficiency and the resulting upper limits on the event rate as function of peak magnitude. Further, we discuss the discoveries of five previously unknown foreground variables which we identified as two flare stars, two W UMa-type eclipsing binaries and a candidate delta Scuti/SX Phe star. C1 [Rau, A.; Ofek, E. O.; Kulkarni, S. R.] CALTECH, Opt Observ, Pasadena, CA 91125 USA. [Madore, B. F.] Observ Carnegie Inst Washington, Pasadena, CA 91101 USA. [Pevunova, O.] CALTECH, Jet Prop Lab, Infrared Proc & Anal Ctr, Pasadena, CA 91125 USA. [Ajello, M.] Max Planck Inst Extraterr Phys, D-80748 Garching, Germany. RP Rau, A (reprint author), CALTECH, Opt Observ, Mail Stop 105-24, Pasadena, CA 91125 USA. NR 40 TC 9 Z9 9 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 AUG 1 PY 2008 VL 682 IS 2 BP 1205 EP 1216 DI 10.1086/589762 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 331PZ UT WOS:000258026100045 ER PT J AU Shkolnik, E Liu, MC Reid, IN Hebb, L Cameron, AC Torres, CA Wilson, DM AF Shkolnik, Evgenya Liu, Michael C. Reid, I. Neill Hebb, Leslie Cameron, Andrew C. Torres, Carlos A. Wilson, David M. TI BD -22 5866: A low-mass, quadruple-lined spectroscopic and eclipsing binary SO ASTROPHYSICAL JOURNAL LA English DT Article DE binaries : eclipsing; binaries : spectroscopic; stars : activity; stars : individual (BD-22 5866); stars : late-type; stars : low-mass, brown dwarfs ID SOLAR-TYPE STARS; RADIAL-VELOCITY; MAIN-SEQUENCE; EVOLUTIONARY MODELS; COOL NEIGHBORS; OPEN CLUSTERS; SYSTEM; CATALOG; MULTIPLICITY; COMPANIONS AB We report our discovery of an extremely rare, low-mass, quadruple-lined spectroscopic binary BD -22 5866 (=NLTT 53279, integrated spectral type = M0 V), found during an ongoing search for the youngest M dwarfs in the solar neighborhood. From the cross-correlation function, we are able to measure relative flux levels, estimate the spectral types of the components, and set upper limits on the orbital periods and separations. The resulting system is hierarchical, composed of a K7 + K7 binary and an M1 + M2 binary with semimajor axes of a(A) sin i(A) <= 0.06 and a(B) sin i(B) <= 0: 30 AU. A subsequent search of the SuperWASP photometric database revealed that the K7 + K7 binary is eclipsing with a period of 2.21 days and at an inclination angle of 85 degrees. Within uncertainties of 5%, the masses and radii of both components appear to be equal (0.59M(circle dot), 0.61 R-circle dot). These two tightly orbiting stars (a = 0.035 AU) are in synchronous rotation, causing the observed excess Ca II, H alpha, X-ray, and UV emission. The fact that the system was unresolved with published adaptive optics imaging, limits the projected physical separation of the two binaries at the time of the observation to d(AB) <= 4.1 AU at the photometric distance of 51 pc. The maximum observed radial velocity difference between the A and B binaries limits the orbit to a(AB) sin i(AB) <= 6.1 AU. As this tight configuration is difficult to reproduce with current formation models of multiple systems, we speculate that an early dynamical process reduced the size of the system, such as the interaction of the two binaries with a circumquadruple disk. Intensive photometric, spectroscopic, and interferometric monitoring, as well as a parallax measurement of this rare quadruple system, is certainly warranted. C1 [Shkolnik, Evgenya] Univ Hawaii, NASA Astrobiol Inst, Inst Astron, Honolulu, HI 96822 USA. [Liu, Michael C.] Univ Hawaii, Inst Astron, Honolulu, HI 96822 USA. [Reid, I. Neill] Space Telescope Sci Inst, Baltimore, MD 21218 USA. [Hebb, Leslie; Cameron, Andrew C.] Univ St Andrews, Sch Phys & Astron, St Andrews KY16 9SS, Fife, Scotland. [Torres, Carlos A.] MCT, Lab Nacl Astrofis, BR-37504364 Itajuba, Brazil. [Wilson, David M.] Keele Univ, Astrophys Grp, Keele ST5 5BG, Staffs, England. RP Shkolnik, E (reprint author), Univ Hawaii, NASA Astrobiol Inst, Inst Astron, 2680 Woodlawn Dr, Honolulu, HI 96822 USA. EM shkolnik@ifa.hawaii.edu; mliu@ifa.hawaii.edu; inr@stsci.edu; leslie.hebb@st-andrews.ac.uk; andrew.cameron@st-and.ac.uk; beto@lna.br; dw@astro.keele.ac.uk NR 59 TC 20 Z9 22 U1 3 U2 7 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 AUG 1 PY 2008 VL 682 IS 2 BP 1248 EP 1255 DI 10.1086/589850 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 331PZ UT WOS:000258026100048 ER PT J AU Leggett, SK Saumon, D Albert, L Cushing, MC Liu, MC Luhman, KL Marley, MS Kirkpatrick, JD Roellig, TL Allers, KN AF Leggett, S. K. Saumon, D. Albert, Loic Cushing, Michael C. Liu, Michael C. Luhman, K. L. Marley, M. S. Kirkpatrick, J. Davy Roellig, Thomas L. Allers, K. N. TI HN Peg B: A test of models of the L to T dwarf transition SO ASTROPHYSICAL JOURNAL LA English DT Article DE binaries : visual; stars : individual (2MASS J21442847+1446077, HN Peg, HN Peg B); stars : low-mass, brown dwarfs ID SPITZER-SPACE-TELESCOPE; STAR ADAPTIVE OPTICS; EXTRASOLAR GIANT PLANETS; INFRARED ARRAY CAMERA; EXOPLANET HOST STAR; L/T TRANSITION; BROWN DWARFS; CHEMICAL-EQUILIBRIUM; GLIESE 570D; FILTER SET AB Luhman and collaborators recently discovered an early-T dwarf companion to the G0 dwarf star HN Peg, using Spitzer Infrared Array Camera (IRAC) images. Companionship was established on the basis of the common proper motion inferred from 1998 Two Micron All Sky Survey images and the 2004 IRAC images. In this paper we present new near-infrared imaging data which confirm the common proper motion of the system. We also present new 3-4 mu m spectroscopy of HN Peg B, which provides tighter constraints on both the bolometric luminosity determination and the comparison to synthetic spectra. New adaptive optics imaging data are also presented, which show the T dwarf to be unresolved, providing limits on the multiplicity of the object. We use the age, distance, and luminosity of the solar-metallicity T dwarf to determine its effective temperature and gravity, and compare synthetic spectra with these values, and a range of grain properties and vertical mixing, to the observed 0.8-4.0 mu m spectra and mid-infrared photometry. We find that models with temperature and gravity appropriate for the older end of the age range of the system (0.5 Gyr) can do a reasonable job of fitting the data, but only if the photospheric condensate cloud deck is thin, and if there is significant vertical mixing in the atmosphere. Dwarfs such as HN Peg B, with well-determined metallicity, radius, gravity, and temperature, will allow development of dynamical atmosphere models, leading to the solution of the puzzle of the L to T dwarf transition. C1 [Leggett, S. K.] Gemini Observ, No Operat Ctr, Hilo, HI 96720 USA. [Saumon, D.] Los Alamos Natl Lab, Los Alamos, NM 87545 USA. [Albert, Loic] Canada France Hawaii Telescope Corp, Kamuela, HI 96743 USA. [Cushing, Michael C.; Liu, Michael C.; Allers, K. N.] Univ Hawaii, Inst Astron, Honolulu, HI 96822 USA. [Luhman, K. L.] Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA. [Marley, M. S.; Roellig, Thomas L.] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. [Kirkpatrick, J. Davy] CALTECH, IPAC, Pasadena, CA 91125 USA. RP Leggett, SK (reprint author), Gemini Observ, No Operat Ctr, 670 N Aohoku Pl, Hilo, HI 96720 USA. RI Marley, Mark/I-4704-2013; OI Leggett, Sandy/0000-0002-3681-2989 NR 49 TC 32 Z9 32 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 AUG 1 PY 2008 VL 682 IS 2 BP 1256 EP 1263 DI 10.1086/589146 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 331PZ UT WOS:000258026100049 ER PT J AU McLaughlin, JA Ofman, L AF McLaughlin, J. A. Ofman, L. TI Three-dimensional magnetohydrodynamic wave behavior in active regions: Individual loop density structure SO ASTROPHYSICAL JOURNAL LA English DT Article DE MHD; Sun : corona; Sun : magnetic fields; Sun : oscillations; waves ID CURVED CORONAL LOOPS; FAST MAGNETOACOUSTIC WAVES; MODE KINK OSCILLATIONS; MAGNETIC-FLUX TUBES; ALFVEN WAVES; RESONANT ABSORPTION; VERTICAL OSCILLATIONS; NUMERICAL SIMULATIONS; SOLAR CORONA; SURFACE-WAVES AB We present the numerical results from a three-dimensional (3D) nonlinear MHD simulation of wave activity in an idealized active region in which individual, realistic loop density structure is included. The active region is modeled by an initially force-free, dipole magnetic configuration with gravitationally stratified density and contains a loop with a higher density than its surroundings. This study represents an extension to the model of Ofman & Thompson. As found in their work, we see that fast wave propagation is distorted by the Alfven speed profile and that the wave propagation generates field line oscillations, which are rapidly damped. We find that the addition of a high-density loop significantly changes the behavior inside that loop, specifically in that the loop can support trapped waves. We also find that the impact of the fast wave impulsively excites both horizontal and vertical loop oscillations. From a parametric study of the oscillations, we find that the amplitude of the oscillations decreases with increasing density contrast, whereas the period and damping time increase. This is one of the key results presented here: that individual loop density structure can influence the damping rate, and specifically that the damping time increases with increasing density contrast. All these results were compared with an additional study performed on a straight coronal loop with similar parameters. Through comparison with the straight loop, we find that the damping mechanism in our curved loop is wave leakage due to curvature. The work performed here highlights the importance of including individual loop density structure in the modeling of active regions and illustrates the need for obtaining accurate density measurements for coronal seismology. C1 [McLaughlin, J. A.; Ofman, L.] NASA, Goddard Space Flight Ctr, Catholic Univ Amer, Greenbelt, MD 20771 USA. RP McLaughlin, JA (reprint author), Univ St Andrews, Sch Math & Stat, St Andrews KY16 9SS, Fife, Scotland. EM james@mcs.st-and.ac.uk NR 78 TC 35 Z9 35 U1 1 U2 5 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 AUG 1 PY 2008 VL 682 IS 2 BP 1338 EP 1350 DI 10.1086/588799 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 331PZ UT WOS:000258026100057 ER PT J AU Klimchuk, JA Patsourakos, S Cargill, PJ AF Klimchuk, J. A. Patsourakos, S. Cargill, P. J. TI Highly efficient modeling of dynamic coronal loops SO ASTROPHYSICAL JOURNAL LA English DT Article DE hydrodynamics; methods : numerical; stars : coronae; Sun : corona; Sun : transition region ID SOFT-X-RAY; SUN TRANSITION REGION; CONTINUUM ABSORPTION; HEATING MODELS; ACTIVE-REGION; SOLAR; TRACE; TEMPERATURE; TELESCOPE; PLASMA AB Observational and theoretical evidence suggests that coronal heating is impulsive and occurs on very small cross-field spatial scales. A single coronal loop could contain a hundred or more individual strands that are heated quasi-independently by nanoflares. It is therefore an enormous undertaking to model an entire active region or the global corona. Three-dimensional MHD codes have inadequate spatial resolution, and one-dimensional (1D) hydrodynamic codes are too slow to simulate the many thousands of elemental strands that must be treated in a reasonable representation. Fortunately, thermal conduction and flows tend to smooth out plasma gradients along the magnetic field, so zero-dimensional (0D) models are an acceptable alternative. We have developed a highly efficient model called "enthalpy-based thermal evolution of loops'' (EBTEL), which accurately describes the evolution of the average temperature, pressure, and density along a coronal strand. It improves significantly on earlier models of this type-in accuracy, flexibility, and capability. It treats both slowly varying and highly impulsive coronal heating; it provides the time-dependent differential emission measure distribution, DEM(T), at the transition region footpoints; and there are options for heat flux saturation and nonthermal electron beam heating. EBTEL gives excellent agreement with far more sophisticated 1D hydrodynamic simulations despite using 4 orders of magnitude less computing time. It promises to be a powerful new tool for solar and stellar studies. C1 [Klimchuk, J. A.; Patsourakos, S.] USN, Res Lab, Div Space Sci, Washington, DC 20375 USA. [Cargill, P. J.] Univ London Imperial Coll Sci Technol & Med, Blackett Lab, London SW7 2BW, England. [Patsourakos, S.] George Mason Univ, Ctr Earth Observing & Space Res, Sch Computat Sci, Fairfax, VA 22030 USA. RP Klimchuk, JA (reprint author), NASA, Goddard Space Flight Ctr, Code 671, Greenbelt, MD 20771 USA. EM James.A.Klimchuk@nasa.gov RI Klimchuk, James/D-1041-2012 OI Klimchuk, James/0000-0003-2255-0305 NR 47 TC 121 Z9 123 U1 0 U2 6 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 AUG 1 PY 2008 VL 682 IS 2 BP 1351 EP 1362 DI 10.1086/589426 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 331PZ UT WOS:000258026100058 ER PT J AU Jess, DB Rabin, DM Thomas, RJ Brosius, JW Mathioudakis, M Keenan, FP AF Jess, D. B. Rabin, D. M. Thomas, R. J. Brosius, J. W. Mathioudakis, M. Keenan, F. P. TI Transition region velocity oscillations observed by EUNIS-06 SO ASTROPHYSICAL JOURNAL LA English DT Article DE Sun : activity; Sun : oscillations; Sun : transition region; Sun : UV radiation ID CORONAL LOOP OSCILLATIONS; HIGH-FREQUENCY OSCILLATIONS; ACTIVE-REGION; SOLAR CORONA; WAVELET ANALYSIS; SOUNDING ROCKET; SUNSPOT UMBRAE; QUIET-SUN; TRACE; NETWORK AB Spectroscopic measurements of NOAA AR 10871, obtained with the Extreme Ultraviolet Normal Incidence Spectrograph (EUNIS) sounding rocket instrument on 2006 April 12, reveal velocity oscillations in the He II 303.8 angstrom emission line formed at T approximate to 5; 10(4) K. The oscillations appear to arise in a bright active region loop arcade about 25 '' wide which crosses the EUNIS slit. The period of these transition region oscillations is 26 +/- 4 s, coupled with a velocity amplitude of +/- 10 km s(-1), detected over four complete cycles. Similar oscillations are observed in lines formed at temperatures up to T approximate to 4; 10(5) K, but we find no evidence for the coupling of these velocity oscillations with corresponding phenomena in the corona. We interpret the detected oscillations as originating from an almost purely adiabatic plasma, and infer that they are generated by the resonant transmission of MHD waves through the lower active region atmospheres. Through the use of seismological techniques, we establish that the observed velocity oscillations display wave properties most characteristic of fast body global sausage modes. C1 [Jess, D. B.; Mathioudakis, M.; Keenan, F. P.] Queens Univ Belfast, Sch Math & Phys, Astrophys Res Ctr, Belfast BT7 1NN, Antrim, North Ireland. [Brosius, J. W.] NASA, Goddard Space Flight Ctr, Solar Phys Lab, Catholic Univ Amer, Greenbelt, MD 20771 USA. RP Jess, DB (reprint author), Queens Univ Belfast, Sch Math & Phys, Astrophys Res Ctr, Belfast BT7 1NN, Antrim, North Ireland. EM djess01@qub.ac.uk NR 48 TC 10 Z9 10 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 AUG 1 PY 2008 VL 682 IS 2 BP 1363 EP 1369 DI 10.1086/589231 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 331PZ UT WOS:000258026100059 ER PT J AU Jacoutot, L Kosovichev, AG Wray, AA Mansour, NN AF Jacoutot, L. Kosovichev, A. G. Wray, A. A. Mansour, N. N. TI Numerical simulation of excitation of solar oscillation modes for different turbulent models SO ASTROPHYSICAL JOURNAL LA English DT Article DE convection; methods : numerical; Sun : oscillations ID P-MODES; RADIAL OSCILLATIONS; CONVECTION; PERFORMANCE; STATE; SUN AB The goal of this research is to investigate how well various turbulence models can describe the physical properties of the upper convective boundary layer of the Sun. Accurate modeling of these turbulent motions is necessary for understanding the excitation mechanisms of solar oscillation modes. We have carried out realistic numerical simulations using a hyperviscosity approach and various physical Large-Eddy Simulation (LES) models (Smagorinsky and dynamic models) to investigate how the differences in turbulence modeling affect the damping and excitation of the oscillations and their spectral properties and to compare with observations. We have first calculated the oscillation power spectra of radial and nonradial modes supported by the computational box with the different turbulence models, followed by calculation of the work integral input to the modes to estimate the influence of the turbulence model on the depth and strength of the oscillation sources. We have compared these results with previous studies and with the observed properties of solar oscillations. We find that the dynamic turbulence model provides the best agreement with the helioseismic observations. C1 [Jacoutot, L.] Stanford Univ, Ctr Turbulence Res, Stanford, CA 94305 USA. [Kosovichev, A. G.] Hansen Expt Phys Lab, Stanford, CA 94305 USA. [Wray, A. A.; Mansour, N. N.] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Jacoutot, L (reprint author), Stanford Univ, Ctr Turbulence Res, Stanford, CA 94305 USA. EM jacoutot@stanford.edu; sasha@sun.stanford.edu; alan.a.wray@nasa.gov; nagi.n.mansour@nasa.gov NR 27 TC 26 Z9 26 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 AUG 1 PY 2008 VL 682 IS 2 BP 1386 EP 1391 DI 10.1086/589226 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 331PZ UT WOS:000258026100062 ER PT J AU Barmby, P Huang, JS Ashby, MLN Eisenhardt, PRM Fazio, GG Willner, SP Wright, EL AF Barmby, P. Huang, J. -S. Ashby, M. L. N. Eisenhardt, P. R. M. Fazio, G. G. Willner, S. P. Wright, E. L. TI A CATALOG OF MID-INFRARED SOURCES IN THE EXTENDED GROTH STRIP SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE catalogs; galaxies: high-redshift; infrared: galaxies; surveys ID SPITZER-SPACE-TELESCOPE; INFRARED ARRAY CAMERA; LYMAN BREAK GALAXIES; DEEP-FIELD-SOUTH; SPECTRAL ENERGY-DISTRIBUTIONS; MULTIBAND IMAGING PHOTOMETER; ACTIVE GALACTIC NUCLEI; DIGITAL SKY SURVEY; LUMINOSITY FUNCTIONS; SCUBA GALAXIES AB The Extended Groth Strip (EGS) is one of the premier fields for extragalactic deep surveys. Deep observations of the EGS with the Infrared Array Camera (IRAC) on the Spitzer Space Telescope cover an area of 0.38 deg(2) to a 50% completeness limit of 1.5 mu Jy at 3.6 mu m. The catalog comprises 57,434 objects detected at 3.6 mu m, with 84%, 28%, and 24% also detected at 4.5, 5.8, and 8.0 mu m, respectively. Number counts are consistent with results from other Spitzer surveys. Color distributions show that the EGS IRAC sources comprise a mixture of populations: low-redshift star-forming galaxies, quiescent galaxies dominated by stellar emission at a range of redshifts, and high-redshift galaxies and AGNs. C1 [Barmby, P.; Huang, J. -S.; Ashby, M. L. N.; Fazio, G. G.; Willner, S. P.] Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. [Eisenhardt, P. R. M.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Wright, E. L.] UCLA Astron, Los Angeles, CA 90095 USA. RP Barmby, P (reprint author), Univ Western Ontario, Dept Phys & Astron, London, ON N6A 3K7, Canada. EM pbarmby@uwo.ca RI Barmby, Pauline/I-7194-2016 OI Barmby, Pauline/0000-0003-2767-0090 FU NASA through an award issued by JPL/Caltech FX We thank the referee for a thorough review which pointed out several important issues. 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 through an award issued by JPL/Caltech. NR 41 TC 64 Z9 64 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 AUG PY 2008 VL 177 IS 2 BP 431 EP 445 DI 10.1086/588583 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 400IS UT WOS:000262861900002 ER PT J AU Chandrasekar, V Hou, A Smith, E Bringi, VN Rutledge, SA Gorgucci, E Petersen, WA Skofronick-Jackson, G AF Chandrasekar, V. Hou, Arthur Smith, Eric Bringi, V. N. Rutledge, S. A. Gorgucci, E. Petersen, W. A. Skofronick-Jackson, Gail TI Potential role of dual-polarization radar in the validation of satellite precipitation measurements: Rationale and opportunities SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID RAINDROP SIZE DISTRIBUTION; DIFFERENTIAL PHASE-SHIFT; IN-SITU VERIFICATION; 2D VIDEO DISDROMETER; POLARIMETRIC RADAR; AXIS RATIOS; HYDROMETEOR CLASSIFICATION; MULTIPARAMETER RADAR; SPACEBORNE RADAR; LABORATORY MEASUREMENTS AB Dual-polarization weather radars have evolved significantly in the last three decades culminating in operational deployment by the National Weather Service. In addition to operational applications in the weather service, dual-polarization radars have shown significant potential in contributing to the research fields of ground-based remote sensing of rainfall microphysics, the study of precipitation evolution, and hydrometeor classification. Microphysical characterization of precipitation and quantitative precipitation estimation are important applications that are critical in the validation of satellite-borne precipitation measurements and also serve as valuable tools in algorithm development. This paper presents the important role played by dual-polarization radar in validating spaceborne precipitation measurements. Examples of raindrop size distribution retrievals and hydrometeor-type classification are discussed. The quantitative precipitation estimation is a product of direct relevance to spaceborne observations. During the Tropical Rainfall Measuring Mission (TRMM) program substantial advancement was made with ground-based polarization radars collecting unique observations in the tropics, which are noted. The scientific accomplishments of relevance to spaceborne measurements of precipitation are summarized. The potential of dual-polarization radars and opportunities in the era of the global precipitation measurement mission is also discussed. C1 [Chandrasekar, V.; Bringi, V. N.; Rutledge, S. A.] Colorado State Univ, Ft Collins, CO 80523 USA. [Hou, Arthur; Smith, Eric; Skofronick-Jackson, Gail] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Gorgucci, E.] Ist Sci Atmosfera & Clima CNR, Rome, Italy. [Petersen, W. A.] NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Chandrasekar, V (reprint author), Colorado State Univ, 1373 Campus Delivery, Ft Collins, CO 80523 USA. EM chandra@engr.colostate.edu RI Skofronick-Jackson, Gail/D-5354-2012; Hou, Arthur/D-8578-2012 FU NASA; National Science Foundation; Italian Space Agency FX The authors acknowledge support from NASA, the National Science Foundation, and the Italian Space Agency via grants over the years that have contributed to the research results presented in this article. NR 71 TC 41 Z9 41 U1 0 U2 1 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 AUG PY 2008 VL 89 IS 8 BP 1127 EP + DI 10.1175/2008BAMS2177.1 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 346HG UT WOS:000259058800012 ER PT J AU Liu, CC Miller, RL AF Liu, Cheng-Chien Miller, Richard L. TI Spectrum matching method for estimating the chlorophyll-a concentration, CDOM ratio, and backscatter fraction from remote sensing of ocean color SO CANADIAN JOURNAL OF REMOTE SENSING LA English DT Article ID OPTICAL-PROPERTIES; PHASE FUNCTION; LIGHT FIELDS; WATERS; MODEL; ALGORITHMS; ABSORPTION; SEAWIFS; PHYTOPLANKTON; REFLECTANCE AB Light emerging from the sea surface carries information about the water constituents, which also includes contributions from inelastic processes, such as Raman scattering, chlorophyll fluorescence, and colored dissolved organic matter (CDOM) fluorescence. The inclusion of inelastic processes, however, has not been fully considered in most of the existing ocean color algorithms. This research presents an approach to substantially decrease the computation time of the nonlinear optimization approach using a look-up table (LUT) to correct for the effects of inelastic scattering. A series of sensitivity tests was conducted to determine the factors required to accurately simulate remote sensing reflectance. Our results show that the inherent optical properties (IOPs) and inelastic scattering play a significant role, whereas the role played by variations of the ambient optical environment and surface wind speed is negligible. An LUT was derived from 22 575 forward simulations using the Hydrolight radiative transfer model. A flexible parameterization of IOPs was formulated by considering all processes of inelastic scattering and a set of three-variable (chlorophyll-a concentration, CDOM ratio, and backscattering fraction) biooptical models. The set of models can be applied to case 1 waters and case 2 waters that happen to be gelbstoff rich, and the volume-scattering phase function can be generated dynamically based on the backscatter fraction. This research may provide a new approach of inversion for including inelastic processes in developing ocean color algorithms. C1 [Liu, Cheng-Chien] Natl Cheng Kung Univ, Earth Dynam Syst Res Ctr, Inst Satellite Informat & Earth Environm, Dept Earth Sci, Tainan 701, Taiwan. [Miller, Richard L.] NASA, Earth Sci Applicat Directorate, Stennis Space Ctr, MS 39529 USA. RP Liu, CC (reprint author), Natl Cheng Kung Univ, Earth Dynam Syst Res Ctr, Inst Satellite Informat & Earth Environm, Dept Earth Sci, Tainan 701, Taiwan. EM ccliu88@mail.ncku.edu.tw FU National Science Council of the Republic of China, Taiwan [NSC-95-2625-Z-006-004-MY3, NSC-96-2611-M-006-002]; Landmark project [B-023] FX The authors gratefully acknowledge financial support provided by the National Science Council of the Republic of China, Taiwan, under contract numbers NSC-95-2625-Z-006-004-MY3 and NSC-96-2611-M-006-002 and the Landmark project under contract number B-023. NR 40 TC 10 Z9 10 U1 0 U2 5 PU CANADIAN AERONAUTICS SPACE INST PI KANATA PA 350 TERRY FOX DR, STE 104, KANATA, ON K2K 2W5, CANADA SN 1712-7971 J9 CAN J REMOTE SENS JI Can. J. Remote Sens. PD AUG PY 2008 VL 34 IS 4 BP 343 EP 355 PG 13 WC Remote Sensing SC Remote Sensing GA 383RZ UT WOS:000261692400001 ER PT J AU Lee, K Wu, CT Clarke, GV Lee, SW AF Lee, K. Wu, C. T. Clarke, G. V. Lee, S. W. TI Computational Modeling of a Lightweight Composite Space Reflector using Geometrically Nonlinear Solid Shell Elements SO CMES-COMPUTER MODELING IN ENGINEERING & SCIENCES LA English DT Article DE Composite space reflector; assumed strain solid shell element; geometrically nonlinear analysis ID ASSUMED-STRAIN; FINITE-ELEMENTS; FORMULATION; PLATE AB A geometrically nonlinear finite element analysis of a low area] density composite space reflector is conducted under static conditions and the results are compared with independently carried out experimental data. The finite element analysis is based on an assumed strain formulation of a geometrically nonlinear nine-node solid shell element. Numerical results are in good agreement with experimental data. This demonstrates the effectiveness of the present solid shell element approach when applied to the analysis of highly flexible space structures. The results of numerical analysis and the experimental data reported in the present paper provide a benchmark for future investigations on the modeling and analysis of geometrically nonlinear composite shell structures via computational tools. C1 [Lee, K.; Lee, S. W.] Univ Maryland, College Pk, MD 20742 USA. [Wu, C. T.] Natl Chiao Tung Univ, Hsinchu, Taiwan. [Clarke, G. V.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Lee, K (reprint author), Univ Maryland, College Pk, MD 20742 USA. NR 14 TC 2 Z9 2 U1 0 U2 0 PU TECH SCIENCE PRESS PI NORCROSS PA 6825 JIMMY CARTER BLVD, STE 1850, NORCROSS, GA 30071 USA SN 1526-1492 J9 CMES-COMP MODEL ENG JI CMES-Comp. Model. Eng. Sci. PD AUG PY 2008 VL 33 IS 1 BP 109 EP 129 PG 21 WC Engineering, Multidisciplinary; Mathematics, Interdisciplinary Applications SC Engineering; Mathematics GA 380RE UT WOS:000261482100005 ER PT J AU Coyle, KO Pinchuk, AI Eisner, LB Napp, JM AF Coyle, Kenneth O. Pinchuk, Alexei I. Eisner, Lisa B. Napp, Jeffrey M. TI Zooplankton species composition, abundance and biomass on the eastern Bering Sea shelf during summer: The potential role of water-column stability and nutrients in structuring the zooplankton community SO DEEP-SEA RESEARCH PART II-TOPICAL STUDIES IN OCEANOGRAPHY LA English DT Article DE Zooplankton; Hydrography; Stability; Nutrients; Alaska; Bering Sea ID POLLOCK THERAGRA-CHALCOGRAMMA; AGE-0 WALLEYE POLLOCK; ATLANTIC RIGHT WHALES; TEMPORAL VARIABILITY; ANOMALOUS CONDITIONS; PELAGIC ECOSYSTEM; PRIBILOF ISLANDS; PACIFIC SALMON; AURELIA-AURITA; CLIMATE-CHANGE AB The southeastern Bering Sea sustains one of the largest fisheries in the United States, as well as wildlife resources that support valuable tourist and subsistence economies. The fish and wildlife populations in turn are sustained by a food web linking primary producers to apex predators through the zooplankton community. Recent shifts in climate toward warmer conditions may threaten these resources by altering productivity and trophic relationships in the ecosystem on the southeastern Bering Sea shelf. We examined the zooplankton community near the Pribilof Islands and on the middle shelf of the southeastern Bering Sea in summer of 1999 and 2004 to document differences and similarities in species composition, abundance and biomass by region and year. Between August 1999 and August 2004, the summer zooplankton community of the middle shelf shifted from large to small species. Significant declines were observed in the biomass of large scyphozoans (Chrysaora melanaster), large copepods (Calanus marshallae), arrow worms (Sagitta elegans) and euphausiids (Thysanoessa raschii, T inermis) between 1999 and 2004. In contrast, significantly higher densities of the small copepods (Pseudocalanus spp., Oithona similis) and small hydromedusae (Euphysa flammea) were observed in 2004 relative to 1999. Stomach analyses of young-of-the-year (age 0) pollock (Theragra chalcogramma) from the middle shelf indicated a dietary shift from large to small copepods in 2004 relative to 1999. The shift in the zooplankton community was accompanied by a 3-fold increase in water-column stability in 2004 relative to 1999, primarily due to warmer water above the thermocline, with a mean temperature of 7.3 degrees C in 1999 and 12.6 degrees C in 2004. The elevated water-column stability and warmer conditions may have influenced the zooplankton composition by lowering summer primary production and selecting for species more tolerant of a warm, oligotrophic environment. A time series of temperature from the middle shelf indicates that the warmer conditions in 2004 are part of a trend rather than an expression of interannual variability. These results suggest that if climate on the Bering Sea shelf continues to warm, the zooplankton community may shift from large to small taxa which could strongly impact apex predators and the economies they support. (C) 2008 Elsevier Ltd. All rights reserved. C1 [Coyle, Kenneth O.] Univ Alaska, Inst Marine Sci, Fairbanks, AK 99775 USA. [Pinchuk, Alexei I.] Univ Alaska, Seward Marine Ctr, Seward, AK 99664 USA. [Eisner, Lisa B.] NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Auke Bay Lab, Juneau, AK 99801 USA. [Napp, Jeffrey M.] NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Seattle, WA 98115 USA. RP Coyle, KO (reprint author), Univ Alaska, Inst Marine Sci, Fairbanks, AK 99775 USA. EM coyle@ims.uaf.edu FU Office of Polar Programs; National Science Foundation [OPP-0326561]; Inner Front Project [OPP-9617287, OPP-9819273]; CIFAR [NA67RJ0147]; NOAA; Bering Sea Fisherman's Association; Fisherman's Association FX This research was conducted on the R.V. Alpha Helix. Technical support was provided by the captain, crew and ships technicians (Steve Hartz, Brian Rowe, Dave Aldridge and Dan Mahalck). Aid in sample processing and data entry was provided by Chris Stark, Janet Ballek, Carla Delfino and Elizabeth Stockman This research was multidisciplinary, involving the cooperation of a number of researchers and institutions. They include: Phyllis Stabeno, Sigrid Salo and Calvin Mordy (NOAA Pacific Marine Environmental Laboratory), Ray Sambroto (Lamont-Doherty Earth Observatory, Columbia University), Steve Zeeman (University of New England), George Hunt (University of California Irvine), Jaime Jahncke (PRBO Conservation Science, Stinson Beach CA). BASIS zooplankton data were uploaded to the computer and verified by Mary Courtney. BASIS data were collected on board the F/V Sea Storm with assistance from the captain and crew, NOAA staff and Russian scientists from TINRO (Natalia Kuznetsova and Oleg Ivanov). We thank all of the above for their participation in this research effort. This project was funded by the Office of Polar Programs, National Science Foundation Grant number OPP-0326561. Material from 1999 came from the Inner Front Project, funded by Grant numbers OPP-9617287 and OPP-9819273 with supplemental support from CIFAR Grant number NA67RJ0147. BASIS research was funded by NOAA, with supplemental support from the Bering Sea Fisherman's Association. The Yukon River Drainage Fisherman's Association also provided financial support for survey scientists. NR 75 TC 71 Z9 76 U1 5 U2 31 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0967-0645 EI 1879-0100 J9 DEEP-SEA RES PT II JI Deep-Sea Res. Part II-Top. Stud. Oceanogr. PD AUG PY 2008 VL 55 IS 16-17 BP 1775 EP 1791 DI 10.1016/j.dsr2.2008.04.029 PG 17 WC Oceanography SC Oceanography GA 363SR UT WOS:000260287500009 ER PT J AU Deppe, JL Rotenberry, JT AF Deppe, Jill L. Rotenberry, John T. TI Scale-dependent habitat use by fall migratory birds: Vegetation structure, floristics, and geography SO ECOLOGICAL MONOGRAPHS LA English DT Review DE coastal vegetation; fall migration; forest; geographic variation; habitat associations; land birds; plant species composition; scale-dependent habitat use; stopover ecology; tropics; vegetation architecture; Yucatan Peninsula ID OVERWINTERING NEARCTIC MIGRANTS; MULTIPLE SPATIAL SCALES; YUCATAN PENINSULA; FOREST BIRDS; INSECTIVOROUS BIRDS; RESOURCE SELECTION; LANDBIRD MIGRANTS; FORAGING BEHAVIOR; AUTUMN MIGRATION; SEASONAL-CHANGES AB Animal habitat selection is a central focus of ecology and conservation biology. Understanding habitat associations in migratory animals is particularly complicated because individuals have variable habitat requirements during the annual cycle, across their geographic range, along migratory routes, and at multiple spatial scales. We studied habitat associations of 16 fall Nearctic - Neotropical migratory land birds at two spatial scales at a stopover site along the northern Yucatan coast to examine scale- dependent habitat use, identify proximate cues shaping birds' distributions, and evaluate similarities in habitat use between our tropical stopover site and temperate sites. We addressed scale- dependent habitat associations in two ways, by ( 1) quantifying species' distributions among and within broad vegetation types and ( 2) comparing migrants' associations with architectural gradients between the two spatial scales. We also evaluated the relative importance of vegetation architecture and. oristics in explaining migrants' distributions within broad coastal vegetation types. Bird species were nonrandomly distributed among broad- and. ne- scale vegetation types, and patterns of habitat use varied between the two scales. Moreover, birds had different preferences for vegetation architecture at the two scales, which may re. ect trade- offs between competing demands and/ or reduced variation in vegetation at the small scale in our study. These. ndings illustrate the manner in which spatial scale and range of vegetation variation in. uence perceptions of animal - habitat associations. Within broad coastal vegetation types birds re. ned their distributions in relation to architectural and. oristic attributes, which provided them with redundant and/ or complementary information regarding the distribution of suitable habitat. We suggest that the relative importance of architecture and. oristics is likely scale- dependent. Habitat use at our site was similar to that observed at temperate stopover sites for almost all species, indicating that habitat af. nities are maintained along the migratory route for these eastern populations despite latitudinal changes in environmental factors. We highlight examples of similar patterns observed in other migratory and nonmigratory animals to illustrate the generality of these patterns beyond en route land birds and our tropical site. We also indicate where we expect to see differences and outline areas of research that merit greater attention in order to advance our understanding of animal habitat selection. C1 Univ Calif Riverside, Dept Biol, Riverside, CA 92521 USA. Univ Calif Riverside, Ctr Conservat Biol, Riverside, CA 92521 USA. RP Deppe, JL (reprint author), NASA, Goddard Space Flight Ctr, Hydrospher & Biospher Sci Lab, Code 614-0,8800 Greenbelt Rd, Greenbelt, MD 20771 USA. EM Jill.L.Deppe@nasa.gov NR 116 TC 28 Z9 30 U1 6 U2 54 PU ECOLOGICAL SOC AMER PI WASHINGTON PA 1990 M STREET NW, STE 700, WASHINGTON, DC 20036 USA SN 0012-9615 EI 1557-7015 J9 ECOL MONOGR JI Ecol. Monogr. PD AUG PY 2008 VL 78 IS 3 BP 461 EP 487 DI 10.1890/07-0163.1 PG 27 WC Ecology SC Environmental Sciences & Ecology GA 333IA UT WOS:000258145000009 ER PT J AU Cailloulet, CW Hart, RA Nance, JM AF Cailloulet, C. W., Jr. Hart, R. A. Nance, J. M. TI Growth overfishing in the brown shrimp fishery of Texas, Louisiana, and adjoining Gulf of Mexico EEZ SO FISHERIES RESEARCH LA English DT Article DE brown shrimp fishery; growth overfishing; Gulf of Mexico; Texas; Louisiana; Exclusive Economic Zone ID EX-VESSEL VALUE; REPORTED ANNUAL CATCHES; SOUTH-ATLANTIC COASTS; SIZE COMPOSITION; WHITE SHRIMP; ANNUAL LANDINGS; AUGUST CATCHES; TRENDS; STATES; PINK AB Growth overfishing in the brown shrimp, Farfantepenaeus aztecus, fishery in inshore (estuarine) and offshore (Gulf of Mexico) territorial waters of Texas and Louisiana, and adjoining waters of the United States' (U.S.) Exclusive Economic Zone (EEZ), and its potentially detrimental economic consequences to the harvesting sector, have not been among major concerns of Federal and State shrimp management agencies. Three possible reasons include (1) environmentally influenced variations in recruitment that cause wide fluctuations in annual landings, which tend to obscure effects of fishing, (2) competition between inshore and offshore components of the harvesting sector, and (3) partitioning of management jurisdiction among a Federal council and two State agencies. Wide variations in landings led to beliefs that high levels of fishing mortality were tolerable and recruitment overfishing was of no major concern. This encouraged somewhat laissez-faire management approaches that allowed fishing effort to increase over the years. Our objectives were to determine whether growth overfishing occurred in this fishery during 1960-2006, and whether and how decreases in size of shrimp within the landings, in response to increases in fishing effort, affected inflation-adjusted annual (calendar year) ex-vessel value of the landings, i.e., their value to the harvesting sector. Growth overfishing occurred in the early 1990s, and then abated as fishing effort declined due to rising fuel costs and competition from imported shrimp. However, inflation-adjusted annual ex-vessel value of the landings peaked in 1985, prior to growth overfishing. Management actions implemented in 2001 for Texas' territorial waters, and in the EEZ off Texas and Louisiana in 2006, should limit future fleet expansion and increases in fishing effort, thereby reducing the chances of growth overfishing and its potentially detrimental economic impacts on the harvesting sector. Growth overfishing should be included among the guidelines for future management of this brown shrimp fishery. Published by Elsevier B. V. C1 [Hart, R. A.; Nance, J. M.] Natl Marine Fisheries Serv, Galveston Lab, Galveston, TX 77551 USA. RP Hart, RA (reprint author), Natl Marine Fisheries Serv, Galveston Lab, 4700 Ave U, Galveston, TX 77551 USA. EM rick.hart@noaa.gov NR 24 TC 13 Z9 13 U1 1 U2 25 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0165-7836 J9 FISH RES JI Fish Res. PD AUG PY 2008 VL 92 IS 2-3 BP 289 EP 302 DI 10.1016/j.fishres.2008.01.009 PG 14 WC Fisheries SC Fisheries GA 331NC UT WOS:000258017900016 ER PT J AU Amundson, R Ewing, S Dietrich, W Sutter, B Owen, J Chadwick, O Nishiizumi, K Walvoord, M McKay, C AF Amundson, Ronald Ewing, Stephanie Dietrich, William Sutter, Brad Owen, Justine Chadwick, Oliver Nishiizumi, Kunihiko Walvoord, Michelle McKay, Christopher TI On the in situ aqueous alteration of soils on Mars SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID PATHFINDER LANDING SITE; X-RAY SPECTROMETER; MERIDIANI-PLANUM; CHEMICAL-COMPOSITION; ATACAMA DESERT; GUSEV CRATER; MARTIAN SOIL; ISOTOPIC COMPOSITION; PLANETARY SCIENCE; BURNS FORMATION AB Early (>3 Gy) wetter climate conditions on Mars have been proposed, and it is thus likely that pedogenic processes have occurred there at some point in the past. Soil and rock chemistry of the Martian landing sites were evaluated to test the hypothesis that in situ aqueous alteration and downward movement of solutes have been among the processes that have transformed these portions of the Mars regolith. A geochemical mass balance shows that Martian soils at three landing sites have lost significant quantities of major rock-forming elements and have gained elements that are likely present as soluble ions. The loss of elements is interpreted to have occurred during an earlier stage(s) of weathering that may have been accompanied by the downward transport of weathering products, and the salts are interpreted to be emplaced later in a drier Mars history. Chemical differences exist among the sites, indicating regional differences in soil composition. Shallow soil profile excavations at Gusev crater are consistent with late stage downward migration of salts, implying the presence of small amounts of liquid water even in relatively recent Martian history. While the mechanisms for chemical weathering and salt additions on Mars remain unclear, the soil chemistry appears to record a decline in leaching efficiency. A deep sedimentary exposure at Endurance crater contains complex depth profiles of SO4, Cl, and Br, trends generally consistent with downward aqueous transport accompanied by drying. While no model for the origin of Martian soils can be fully constrained with the currently available data, a pedogenic origin is consistent with observed Martian geology and geochemistry, and provides a testable hypothesis that can be evaluated with present and future data from the Mars surface. (C) 2008 Elsevier Ltd. All rights reserved. C1 [Amundson, Ronald; Ewing, Stephanie; Owen, Justine] Univ Calif Berkeley, Div Ecosyst Sci, Berkeley, CA 94720 USA. [Dietrich, William] Univ Calif Berkeley, Dept Earth & Planetary Sci, Berkeley, CA 94720 USA. [Sutter, Brad] Jacobs NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. [Chadwick, Oliver] Univ Calif Santa Barbara, Dept Geog, Santa Barbara, CA 93106 USA. [Nishiizumi, Kunihiko] Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. [Walvoord, Michelle] US Geol Survey, Denver Fed Ctr, Lakewood, CO 80225 USA. [McKay, Christopher] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Amundson, R (reprint author), Univ Calif Berkeley, Div Ecosyst Sci, 137 Mulford Hall, Berkeley, CA 94720 USA. EM earthy@nature.berkeley.edu RI Amundson, Ronald /E-2654-2015 NR 92 TC 25 Z9 25 U1 3 U2 20 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0016-7037 EI 1872-9533 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD AUG 1 PY 2008 VL 72 IS 15 BP 3845 EP 3864 DI 10.1016/j.gca.2008.04.038 PG 20 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 332NG UT WOS:000258089100017 ER PT J AU Mann, JL Shuman, CA Kelly, WR Kreutz, KJ AF Mann, Jacqueline L. Shuman, Christopher A. Kelly, W. Robert Kreutz, Karl J. TI Seasonal delta S-34 variations in two high elevation snow pits measured by S-33-S-36 double spike thermal ionization mass spectrometry SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID GREENLAND ICE-SHEET; BIOGENIC SULFUR AEROSOL; COMMUNITY CLIMATE MODEL; CENTRAL TIEN-SHAN; ATMOSPHERIC SULFUR; ISOTOPIC COMPOSITION; CENTRAL-ASIA; NITRATE CONCENTRATIONS; ANTHROPOGENIC SULFATE; CHEMICAL-COMPOSITION AB delta S-34 and sulfate concentrations were determined in snow pit samples using a thermal ionization mass spectrometric technique capable of 0.2 parts per thousand. accuracy and requires approximate to 5 mu g (0.16 mu mol) natural S. The technique utilizes a S-33-S-36 double spike for instrumental mass fractionation correction, and has been applied to snow pit samples collected from the Inilchek Glacier, Kyrgyzstan and from Summit, Greenland. These delta S-34 determinations provide the first high-resolution seasonal data for these sites, and are used to estimate seasonal sulfate sources. Deuterium (delta D) and oxygen (delta O-18) isotope data show that the Inilchek and Summit snow pit samples represent precipitation over approximate to 20 months. The delta S-34 values for the Inilchek ranged from +2.6 +/- 0.4 parts per thousand to +7.6 +/- 0.4 parts per thousand on sample sizes ranging from 0.3 to 1.8 mu mol S. delta S-34 values for Greenland ranged from +3.6 +/- 0.7 parts per thousand to +13.3 +/- 5 parts per thousand for sample sizes ranging from 0.05 to 0.29 mu mol S. The SO42- concentration ranged from 92.6 +/- 0.4 to 1049 +/- 4 ng/g for the Inilchek and 18 +/- 9 to 93 +/- 6 ng/g for the Greenland snow pit. Anthropogenic sulfate dominates throughout the sampled time interval for both sites based on mass balance considerations. Additionally, both sites exhibit a seasonal signature in both delta S-34 and SO42- concentration. The thermal ionization mass spectrometric technique has three advantages compared to gas source isotopic methods: (1) sample size requirements of this technique are 10-fold less permitting access to the higher resolution S isotope record of low concentration snow and ice, (2) the double spike technique permits delta S-14 and S concentration to be determined simultaneously, and (3) the double spike is an internal standard. (C) 2008 Elsevier Ltd. All rights reserved. C1 [Mann, Jacqueline L.; Kelly, W. Robert] Natl Inst Stand & Technol, Div Analyt Chem, Chem Sci & Technol Lab, Inorgan Chem Metrol Grp, Gaithersburg, MD 20899 USA. [Mann, Jacqueline L.] Univ Maryland, Dept Geol, College Pk, MD 20742 USA. [Shuman, Christopher A.] Univ Maryland, NASA, Goddard Space Flight Ctr, Goddard Earth Sci & Technol Ctr, Greenbelt, MD 20771 USA. [Kreutz, Karl J.] Univ Maine, Climate Change Inst, Orono, ME 04469 USA. [Kreutz, Karl J.] Univ Maine, Dept Earth Sci, Orono, ME 04469 USA. RP Mann, JL (reprint author), Natl Inst Stand & Technol, Div Analyt Chem, Chem Sci & Technol Lab, Inorgan Chem Metrol Grp, 100 Bur Dr,MS 8391, Gaithersburg, MD 20899 USA. EM jmann@nist.gov NR 90 TC 6 Z9 6 U1 1 U2 6 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 AUG 1 PY 2008 VL 72 IS 15 BP 3907 EP 3927 DI 10.1016/j.gca.2008.05.036 PG 21 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 332NG UT WOS:000258089100020 ER PT J AU Law, RM Peters, W Rodenbeck, C 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 Patra, PK Pieterse, G Rivier, L Satoh, M Serrar, S Taguchi, S Takigawa, M Vautard, R Vermeulen, AT Zhu, Z AF Law, R. M. Peters, W. Roedenbeck, C. 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. Patra, P. K. Pieterse, G. Rivier, L. Satoh, M. Serrar, S. Taguchi, S. Takigawa, M. Vautard, R. Vermeulen, A. T. Zhu, Z. TI TransCom model simulations of hourly atmospheric CO2: Experimental overview and diurnal cycle results for 2002 SO GLOBAL BIOGEOCHEMICAL CYCLES LA English DT Article ID CARBON-DIOXIDE; TRANSPORT; EUROPE; VARIABILITY; INVERSIONS; TRENDS; IMPACT; RECORD; FLUXES; FOREST AB [1] A forward atmospheric transport modeling experiment has been coordinated by the TransCom group to investigate synoptic and diurnal variations in CO2. Model simulations were run for biospheric, fossil, and air-sea exchange of CO2 and for SF6 and radon for 2000-2003. Twenty-five models or model variants participated in the comparison. Hourly concentration time series were submitted for 280 sites along with vertical profiles, fluxes, and meteorological variables at 100 sites. The submitted results have been analyzed for diurnal variations and are compared with observed CO2 in 2002. Mean summer diurnal cycles vary widely in amplitude across models. The choice of sampling location and model level account for part of the spread suggesting that representation errors in these types of models are potentially large. Despite the model spread, most models simulate the relative variation in diurnal amplitude between sites reasonably well. The modeled diurnal amplitude only shows a weak relationship with vertical resolution across models; differences in near-surface transport simulation appear to play a major role. Examples are also presented where there is evidence that the models show useful skill in simulating seasonal and synoptic changes in diurnal amplitude. C1 [Law, R. M.] CSIRO Marine & Atmospher Res, Aspendale, Vic 3195, Australia. [Peters, W.; Bruhwiler, L.] NOAA Earth Syst Res Lab, Boulder, CO 80305 USA. [Peters, W.] Univ Wageningen & Res Ctr, Dept Meteorol & Air Qual, NL-6708 PB Wageningen, Netherlands. [Roedenbeck, C.; Karstens, U.] Max Planck Inst Biogeochem, D-07701 Jena, Germany. [Aulagnier, C.; Bousquet, P.; Delage, F.; Rivier, L.; Vautard, R.] CEA Saclay CNRS UVSQ, LSCE 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 94550 USA. [Brandt, J.; Christensen, J. H.; Geels, C.] Aarhus Univ, Natl Environm Res Inst, Dept Atmospher Environm, DK-4000 Roskilde, Denmark. [Fan, S.; Lin, S. -J.] NOAA Geophys Fluide Dynam Lab, Princeton, NJ 08542 USA. [Houweling, S.; Pieterse, G.] SRON, Netherland Inst Space Res, NL-3584 CA Utrecht, Netherlands. [Imasu, R.; Niwa, Y.; Satoh, M.] Univ Tokyo, Ctr Climate Syst Res, Kashiwa, Chiba 2778568, Japan. [Kawa, S. R.] NASA, Goddard Space Flight Ctr, Greenbelt, MD USA. [Kleist, J.] Privacy Networks, Ft Collins, CO 80521 USA. [Krol, M. C.] SRON, IMAU, NL-3584 CC Utrecht, Netherlands. [Maki, T.] Japan Meteorol Agcy, Div Atmospher Environm, Tokyo 1008122, Japan. [Maksyutov, S.] Natl Inst Environm Studies, Ctr Global Environm Res, Tsukuba, Ibaraki 3058506, Japan. [Patra, P. K.; Takigawa, M.] Frontier Res Ctr Global Change JAMSTEC, Kanazawa Ku, Yokohama, Kanagawa 2360001, Japan. [Onishi, R.] JAMSTEC, Earth Simulator Ctr, Yokohama, Kanagawa 2360001, Japan. [Vermeulen, A. T.] Energy Res Ctr Netherlands ECN, NL-1755 ZG Petten, Netherlands. [Serrar, S.] ECMWF, Reading RG2 9AX, Berks, England. [Taguchi, S.] Natl Inst Adv Ind Sci & Technol, AIST W, Tsukuba, Ibaraki 3058569, Japan. [Zhu, Z.] Sci Syst & Applicat Inc, Lanham, MD 20706 USA. RP Law, RM (reprint author), CSIRO Marine & Atmospher Res, PMB 1, Aspendale, Vic 3195, Australia. EM rachel.law@csiro.au; wouter.peters@wur.nl; christian.roedenbeck@bgc-jena.mpg.de; celine.aulagnier@lsce.ipsl.fr; baker@atmos.colostate.edu; dbergmann@llnl.gov; philippe.bousquet@lsce.ipsl.fr; jbr@dmu.dk; lori.bruhwiler@noaa.gov; pjc@llnl.gov; jc@dmu.dk; francois.delage@cea.fr; denning@atmos.colostate.edu; songmiao.fan@noaa.gov; cag@dmu.dk; s.houweling@phys.uu.nl; imasu@ccsr.u-tokyo.ac.jp; ute.karstens@zmaw.de; stephan.r.kawa@nasa.gov; johnk@privacynetwork.com; m.c.krol@phys.uu.nl; shian-jiann.lin@noaa.gov; ravi@atmos.colostate.edu; maki@met.kishou.go.jp; shamil@nies.go.jp; yniwa@ccsr.u-tokyo.ac.jp; onishi.ryo@jamstec.go.jp; nparazoo@atmos.colostate.edu; prabir@jamstec.go.jp; gerben.pieterse@tno.nl; leonard.rivier@lsce.ipsl.fr; satoh@ccsr.u-tokyo.ac.jp; soumia.serrar@ecmwf.int; s.taguchi@aist.go.jp; takigawa@jamstec.go.jp; robert.vautard@cea.fr; a.vermeulen@ecn.nl; zhu@mulan.gsfc.nasa.gov RI 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; Peters, Wouter/B-8305-2008; Krol, Maarten/B-3597-2010; Denning, Scott/F-4974-2011; Geels, Camilla/G-4757-2013; Krol, Maarten/E-3414-2013; onishi, ryo/D-1109-2014; 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 OI 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; Peters, Wouter/0000-0001-8166-2070; Denning, Scott/0000-0003-3032-7875; Geels, Camilla/0000-0003-2549-1750; onishi, ryo/0000-0001-9250-0712; 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 NR 60 TC 81 Z9 81 U1 1 U2 19 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0886-6236 EI 1944-9224 J9 GLOBAL BIOGEOCHEM CY JI Glob. Biogeochem. Cycle PD AUG 1 PY 2008 VL 22 IS 3 AR GB3009 DI 10.1029/2007GB003050 PG 15 WC Environmental Sciences; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Geology; Meteorology & Atmospheric Sciences GA 333KA UT WOS:000258150200001 ER PT J AU Dever, JA Miller, SK Sechkar, EA Wittberg, TN AF Dever, Joyce A. Miller, Sharon K. Sechkar, Edward A. Wittberg, Thomas N. TI Space environment exposure of polymer films on the materials international space station experiment: Results from MISSE 1 and MISSE 2 SO HIGH PERFORMANCE POLYMERS LA English DT Article; Proceedings Paper CT 10th International Symposium on Materials in a Space Environment CY JUN 19-23, 2006 CL Colliour, FR POLYNESIA SP Off Natl Edudes & Rech Aerospatiales DE space environment; International Space Station; spacecraft thermal control; polymer films ID RAY PHOTOELECTRON-SPECTROSCOPY AB A total of thirty-one samples were included in the National Aeronautics and Space Administration (NASA) Glenn Research Center (GRC) Polymer Film Thermal Control (PFTC) and Gossamer Materials experiments, which were exposed to the low Earth orbit environment for nearly 4 years on the exterior of the International Space Station (ISS) as part of the Materials International Space Station Experiment (MISSE 1 and MISSE 2). This paper describes objectives, materials, and characterizations for the MISSE 1 and MISSE 2 GRC PFTC and Gossamer Materials samples. Samples included films of polyimides, fluorinated polyimides, and Teflon(R) fluorinated ethylene propylene (FEP) with and without second-surface metalized layers and/or surface coatings. Films of polyphenylene benzobisoxazole (PBO) and a polyarylene ether benzimidazole (TOR-LMT(TM)) were also included. Polymer film samples were examined post-flight for changes in mechanical and optical properties. The environment in which the samples were located was characterized through analysis of sapphire contamination witness samples and samples dedicated to atomic oxygen (AO) erosion measurements. Results of the analyses of the PFTC and Gossamer Materials experiments are discussed. C1 [Dever, Joyce A.; Miller, Sharon K.] NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. [Sechkar, Edward A.] ASRC Aerosp Corp, Cleveland, OH USA. [Wittberg, Thomas N.] Univ Dayton, Res Inst, Dayton, OH 45469 USA. RP Dever, JA (reprint author), NASA, Glenn Res Ctr, 21000 Brookpk Rd,MS 106-1, Cleveland, OH 44135 USA. EM Joyce.A.Dever@nasa.gov NR 9 TC 13 Z9 16 U1 1 U2 10 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 AUG-OCT PY 2008 VL 20 IS 4-5 BP 371 EP 387 DI 10.1177/0954008308089704 PG 17 WC Polymer Science SC Polymer Science GA 340VL UT WOS:000258673000002 ER PT J AU De Groh, KK Banks, BA McCarthy, CE Rucker, RN Roberts, LM Berger, LA AF De Groh, Kim K. Banks, Bruce A. McCarthy, Catherine E. Rucker, Rochelle N. Roberts, Lily M. Berger, Lauren A. TI MISSE 2 PEACE polymers atomic oxygen erosion experiment on the International Space Station SO HIGH PERFORMANCE POLYMERS LA English DT Article; Proceedings Paper CT 10th International Symposium on Materials in a Space Environment CY JUN 19-23, 2006 CL Colliour, FR POLYNESIA SP Off Natl Edudes & Rech Aerospatiales DE atomic oxygen; erosion yield; environmental degradation; International Space Station; space experiment; low Earth orbit AB Forty-one different polymer samples, collectively called the Polymer Erosion and Contamination Experiment (PEACE) Polymers, were exposed to the low Earth orbit (LEO) environment on the exterior of the International Space Station (ISS) for nearly 4 years as part of Materials International Space Station Experiment 2 (MISSE 2). The objective of the PEACE Polymers experiment was to determine the atomic oxygen erosion yield of a wide variety of polymeric materials after long-term exposure to the space environment. The polymers range from those commonly used for spacecraft applications, such as Teflon(R) FEP, to more recently developed polymers, such as high temperature polyimide PMR (polymerization of monomer reactants). Additional polymers were included to explore erosion yield dependence upon chemical composition. The MISSE PEACE Polymers experiment was flown in MISSE Passive Experiment Carrier 2 (PEC 2), tray 1, attached to the exterior of the ISS Quest Airlock. It was exposed to atomic oxygen along with solar and charged particle radiation. MISSE 2 was successfully retrieved during a space walk on July 30, 2005 during Discovery's STS-114 Return to Flight mission. Details on the specific polymers flown, flight sample fabrication, pre-flight and post-flight characterization techniques, and atomic oxygen fluence calculations are discussed along with a summary of the atomic oxygen erosion yield results. The MISSE 2 PEACE Polymers experiment is unique because it has the widest variety of polymers flown in LEO for a long duration and was exposed to an unusually clean LEO spacecraft environment. This experiment provides extremely valuable erosion yield data for spacecraft design purposes. C1 [De Groh, Kim K.; Banks, Bruce A.] NASA, Glenn Res Ctr, Alphaport Inc, Cleveland, OH 44135 USA. [McCarthy, Catherine E.; Rucker, Rochelle N.; Roberts, Lily M.; Berger, Lauren A.] Hathaway Brown Sch, Shaker Hts, OH USA. RP De Groh, KK (reprint author), NASA, Glenn Res Ctr, Alphaport Inc, 21000 Brookpk Rd,MS 309-2, Cleveland, OH 44135 USA. EM Kim.K.deGroh@nasa.gov NR 9 TC 27 Z9 27 U1 0 U2 8 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 AUG-OCT PY 2008 VL 20 IS 4-5 BP 388 EP 409 DI 10.1177/0954008308089705 PG 22 WC Polymer Science SC Polymer Science GA 340VL UT WOS:000258673000003 ER PT J AU Groh, KK Snyder, A Finlay, KA AF De Groh, Kim K. Snyder, Aaron Finlay, Katherine A. TI Degradation of Hubble Space Telescope aluminized-Teflon bi-stem thermal shields SO HIGH PERFORMANCE POLYMERS LA English DT Article; Proceedings Paper CT 10th International Symposium on Materials in a Space Environment CY JUN 19-23, 2006 CL Colliour, FR POLYNESIA SP Off Natl Edudes & Rech Aerospatiales DE Hubble Space Telescope; thermal control material; environmental degradation; radiation embrittlement; space exposure ID FEP AB A section of retrieved Hubble Space Telescope (HST) bi-stem thermal shields (BSTS), which experienced 8.25 years of space exposure, was analyzed for space environmental durability. The shields were comprised of 2 mil (0.051 mm) aluminized-Teflon(R) fluorinated ethylene propylene (Al-FEP) rings fused together into a circular bellows shape. As the circular thermal shields had solar, anti-solar and solar-grazing surfaces and were exposed to the space environment for a long duration, it provided a unique opportunity to study solar effects on the environmental degradation of Al-FEP, a commonly used spacecraft thermal control material. Therefore, the objective of this research was to characterize the degradation of retrieved HST BSTS Al-FEP with particular emphasis on solar effects. Data obtained included tensile properties, density (as-retrieved and after 200 degrees C heating), solar absorptance, and surface morphology and chemistry. The solar-facing surfaces of the thermal shields were found to be extremely embrittled and contained numerous through-thickness cracks. Tensile testing verified that near solar-facing surfaces lost their mechanical strength and elasticity, whereas the anti-solar-facing surfaces maintained their ductility. The density of the as-retrieved BSTS insulation was similar to pristine FEP Heating at 200 degrees C resulted in significant increases in density for the solar-facing BSTS indicating chain scission damage, consistent with the loss of mechanical strength and elongation. The solar absorptance of the solar-grazing and the anti-solar-facing surfaces were found to be similar to pristine BSTS, whereas the solar-facing surfaces were found to have significantly increased solar absorptance. Both solar- and anti-solar-facing surfaces were microscopically textured from sweeping atomic oxygen erosion with the solar-facing surface appearing to have a more pronounced texture in spite of being exposed to a lower atomic oxygen fluence indicating a possible solar/atomic oxygen synergistic effect. These results provide valuable information on space environmental degradation of Al-FEP, particularly with respect to solar radiation effects on embrittlement. C1 [De Groh, Kim K.] NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. [Snyder, Aaron] NASA, Glenn Res Ctr, Plum Brook Stn, Sandusky, OH USA. [Finlay, Katherine A.] Ohio Aerosp Inst, Cleveland, OH USA. RP De Groh, KK (reprint author), NASA, Glenn Res Ctr, 21000 Brookpk Rd,MS 309-2, Cleveland, OH 44135 USA. EM kim.k.deGroh@nasa.gov NR 15 TC 1 Z9 1 U1 0 U2 5 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 AUG-OCT PY 2008 VL 20 IS 4-5 BP 410 EP 428 DI 10.1177/0954008308089706 PG 19 WC Polymer Science SC Polymer Science GA 340VL UT WOS:000258673000004 ER PT J AU Waters, DL Banks, BA De Groh, KK Miller, SKR Thorson, SD AF Waters, Deborah L. Banks, Bruce A. De Groh, Kim K. Miller, Sharon K. R. Thorson, Stephen D. TI The atomic oxygen erosion depth and cone height of various materials at hyperthermal energy SO HIGH PERFORMANCE POLYMERS LA English DT Article; Proceedings Paper CT 10th International Symposium on Materials in a Space Environment CY JUN 19-23, 2006 CL Colliour, FR POLYNESIA SP Off Natl Edudes & Rech Aerospatiales DE atomic oxygen; polymers; space environment; erosion depth; cone height AB Atomic oxygen readily reacts with most spacecraft polymer materials exposed to the low Earth orbital (LEO) environment. If the atomic oxygen arrival comes from a fixed angle of impact, the resulting erosion will foster the development of a change in surface morphology as material thickness decreases. Hydrocarbon and halopolymer materials, as well as graphite, are easily oxidized and textured by directed atomic oxygen in LEO at energies of similar to 4.5 eV. What has been curious is that the ratio of cone height to erosion depth is quite different for different materials. The formation of cones under fixed direction atomic oxygen attack may contribute to a reduction in material tensile strength in excess of that which would occur if the cone height to erosion depth ratio was very low because of greater opportunities for crack initiation. In an effort to understand how material composition affects the ratio of cone height to erosion depth, an experimental investigation was conducted on 18 different materials exposed to a hyperthermal energy directed atomic oxygen source (similar to 70 eV). The materials were first salt-sprayed to provide microscopic local areas that would be protected from atomic oxygen. This allowed erosion depth measurements to be made by scanning microscopy inspection. The polymers were then exposed to atomic oxygen produced by an end Hall ion source that was operated on pure oxygen. Samples were exposed to an atomic oxygen effective fluence of 1.0 x 10(20) atoms cm(-2) based on Kapton H polyimide erosion. The average erosion depth and average cone height were determined using field emission scanning electron microscopy (FESEM). The experimental ratio of average cone height to erosion depth is compared to polymer composition and other properties. C1 [Waters, Deborah L.] ASRC Aerosp Corp, Cleveland, OH 44135 USA. [Banks, Bruce A.; De Groh, Kim K.; Miller, Sharon K. R.] NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. [Thorson, Stephen D.] Univ Wisconsin, Madison, WI 53711 USA. RP Waters, DL (reprint author), ASRC Aerosp Corp, 21000 Brookpk Rd, Cleveland, OH 44135 USA. EM Deborah.L.Waters@nasa.gov NR 7 TC 4 Z9 4 U1 0 U2 3 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 AUG-OCT PY 2008 VL 20 IS 4-5 BP 512 EP 522 DI 10.1177/0954008308089712 PG 11 WC Polymer Science SC Polymer Science GA 340VL UT WOS:000258673000010 ER PT J AU Miller, SKR Banks, BA Waters, DL AF Miller, Sharon K. R. Banks, Bruce A. Waters, Deborah L. TI Investigation into the differences between atomic oxygen erosion yields of materials in ground-based facilities and LEO SO HIGH PERFORMANCE POLYMERS LA English DT Article; Proceedings Paper CT 10th International Symposium on Materials in a Space Environment CY JUN 19-23, 2006 CL Colliour, FR POLYNESIA SP Off Natl Edudes & Rech Aerospatiales DE atomic oxygen; synergistic effects; FEP teflon; polyethylene; low Earth orbit; ultraviolet radiation AB The atomic oxygen erosion yields of various materials, measured in terms of volume of material oxidized per incident oxygen atom, are sometimes very different for materials exposed in ground-based atomic oxygen facilities compared to those exposed in low Earth orbit (LEO) for the same materials. This difference has often been attributed to a synergistic reaction between atomic oxygen and vacuum ultraviolet radiation present in many ground-based atomic oxygen facilities. Energy and presence of charged species has also been thought to play a role in this observed difference in erosion yield. Using an isotropic thermal energy atomic oxygen source and a hyperthermal atomic oxygen directed beam, an attempt was made to isolate each of these factors for polyimide Kapton HN, polyethylene, and FEP Teflon to determine the sensitivity of the erosion yield to each factor. It was found that each polymer appears to have atomic oxygen synergistic effects with different components of the environment. Isolating each environmental component to determine the important component for a particular material is an important step in enabling better durability prediction using ground-based facilities. Ground testing using the expected space environment components and the development of correlation factors to better relate the ground test to a particular mission environment are important to project in-space material durability. C1 [Miller, Sharon K. R.; Waters, Deborah L.] NASA, Glenn Res Ctr, QSS Grp, Cleveland, OH 44135 USA. RP Miller, SKR (reprint author), NASA, Glenn Res Ctr, QSS Grp, 21000 Brookpk Rd,MS 309-2, Cleveland, OH 44135 USA. EM sharon.k.miller@nasa.gov NR 12 TC 2 Z9 2 U1 1 U2 5 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 AUG-OCT PY 2008 VL 20 IS 4-5 BP 523 EP 534 DI 10.1177/0954008308089711 PG 12 WC Polymer Science SC Polymer Science GA 340VL UT WOS:000258673000011 ER PT J AU Vernikos, J AF Vernikos, J. TI Human Exploration of Space: why, where, what for? SO HIPPOKRATIA LA English DT Article; Proceedings Paper CT 5th International Meeting of Aerospace Medicine CY AUG 30-SEP 02, 2007 CL Skiathos Isl, GREECE DE human space flight; space market; space medicine research and applications ID HUMAN PHYSIOLOGY AB "Man must rise above Earth to the top of the atmosphere and beyond, for only then will he fully understand the world in which he lives" - Socrates (469-399 BC). The basic driving rationales for human space flight (HSF) are rooted in age-old and persisting dreams. Fascination with the idea of people going into the sky for adventures in other worlds goes back to ancient myths. This paper sheds light onto criticisms of HSF programs, by revisiting their scientific grounds and associated benefits, along with the different types of emerging commercial enterprise. Research from space has lead to a wealth of commercial and societal applications on Earth, building up the case for the so-called "Space Applications Market". C1 NASA, Washington, DC 20546 USA. RP Vernikos, J (reprint author), NASA, Washington, DC 20546 USA. NR 8 TC 2 Z9 2 U1 1 U2 3 PU LITHOGRAPHIA PI THESSALONIKI PA ANTONIADIS I-PSARRAS TH G P, NEA REDESTOS, THESSALONIKI, 00000, GREECE SN 1108-4189 J9 HIPPOKRATIA JI Hippokratia PD AUG PY 2008 VL 12 SU 1 BP 6 EP 9 PG 4 WC Medicine, General & Internal SC General & Internal Medicine GA 353PC UT WOS:000259579000002 PM 19048086 ER PT J AU Fishbaugh, KE Hvidberg, CS Beaty, D Clifford, S Fisher, D Haldemann, A Head, JW Hecht, M Koutnik, M Tanaka, K Ammann, WJ AF Fishbaugh, K. E. Hvidberg, C. S. Beaty, D. Clifford, S. Fisher, D. Haldemann, A. Head, J. W. Hecht, M. Koutnik, M. Tanaka, K. Ammann, W. J. TI Introduction to the 4th Mars Polar Science and Exploration Conference special issue: Five top questions in Mars polar science SO ICARUS LA English DT Editorial Material DE Mars, polar caps; Mars, polar geology; Mars, climate; ices ID GENERAL-CIRCULATION MODEL; ORBITER LASER ALTIMETER; LOBATE DEBRIS APRONS; GLOBAL SURVEYOR DATA; SURFACE GROUND ICE; LAYERED DEPOSITS; CLIMATE-CHANGE; NEAR-SURFACE; WATER ICE; GEOLOGIC HISTORY AB As an introduction to this Icarus special issue for the 4th Mars Polar Science and Exploration Conference, we discuss five key questions in Mars polar science, gleaned from plenary discussions and presentations held at the conference. These questions highlight major unknowns in the field. (1) What are the physical characteristics Of the polar layered deposits (PLD), and how are the different geologic units within, beneath, and surrounding the PLD related? (2) How old are the PLD? And what are their glacial, fluvial, depositional and erosional histories? (3) What are the mass and energy budgets of the PLD, and what processes control these budgets on seasonal and longer timescales? (4) What chronology, compositional variability, and record of climatic change is expressed in the stratigraphy of the PLD? (5) How have volatiles and dust been exchanged between polar and non-polar reservoirs? And how has this exchange affected the past and present distribution of surface and subsurface ice? Published by Elsevier Inc. C1 [Beaty, D.; Haldemann, A.; Hecht, M.] CALTECH, Jet Prop Lab, Pasadena, CA USA. [Fishbaugh, K. E.] ISSI, CH-3012 Bern, Switzerland. [Hvidberg, C. S.] Univ Copenhagen, Niels Bohr Inst, DK-2100 Copenhagen, Denmark. [Clifford, S.] Lunar & Planetary Inst, Houston, TX 77059 USA. [Fisher, D.] Geol Survey Canada, Glaciol Terrain Sci Div, Ottawa, ON K1A 0E8, Canada. [Haldemann, A.] European Space Agcy, European Space Res & Technol Ctr, NL-2200 AG Noordwijk, Netherlands. [Head, J. W.] Brown Univ, Dept Geol Sci, Providence, RI 02912 USA. [Koutnik, M.] Univ Washington, Seattle, WA 98195 USA. [Tanaka, K.] US Geol Survey, Flagstaff, AZ 86001 USA. [Ammann, W. J.] Swiss Fed Inst Snow & Avalanche Res, CH-7260 Davos, Switzerland. RP Fishbaugh, KE (reprint author), Smithsonian Natl Air & Space Museum, Ctr Earth & Planetary Studies, MRC 315,601 Independence Ave SW, Washington, DC 20024 USA. EM fishbaughke@si.edu RI Hvidberg, Christine/E-8934-2015 OI Hvidberg, Christine/0000-0002-9665-1339 NR 145 TC 14 Z9 14 U1 0 U2 13 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 AUG PY 2008 VL 196 IS 2 BP 305 EP 317 DI 10.1016/j.icarus.2008.05.001 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 331TK UT WOS:000258035300001 ER PT J AU Zent, A AF Zent, Aaron TI A historical search for habitable ice at the Phoenix landing site SO ICARUS LA English DT Article; Proceedings Paper CT 4th International Conference on Mars Polar Science and Exploration CY OCT 02-06, 2006 CL Davos, SWITZERLAND DE Mars, climate; astrobiology; Mars, polar geology; Mars, polar caps; exobiology ID GENERAL-CIRCULATION MODEL; MARTIAN POLAR CAPS; GROUND ICE; FREEZING-POINT; SEASONAL CAP; NEAR-SURFACE; WATER-VAPOR; MARS; OBLIQUITY; PERMAFROST AB A time-resolved energy balance model in the latitude range targeted by Phoenix, and extending back in time over the past 10 Ma, has been developed and used to predict the time-varying temperature field in ground ice over scales ranging from minutes to millions of years. The temperature history is compared to the population doubling times of terrestrial psychrophiles as a function of temperature, and the lifetime of analog microbe spores against de-activation by galactic cosmic rays (GCR), in order to assess the habitability of ground ice and surrounding materials that may be sampled by Phoenix. Metrics are derived to quantify "habitability" and compare different model configurations, including total and maximum continuous time, per year, that ground ice temperatures exceed various thresholds, maximum and average dormancy periods, and maximum and average consecutive growing seasons. The key unknowns in assessing the position, and hence the temperature, of the ground ice table at high northern latitude is the fate of the perennial north polar cap at high obliquity. If enough H(2)O ice can persist at polar latitudes to buffer at least the high-latitude atmosphere at all orbital configurations, ground ice is found to be relatively shallow over much of the past 10 Ma, and regularly achieves temperatures in excess of those required for the growth of terrestrial psychrophiles. The dry overburden expected at the landing site can easily be sampled by Phoenix, and includes the "sweet spot" that is characterized by the optimal habitability metrics over the past 10 Ma. If the atmosphere is buffered only by low-latitude ice deposits at obliquities greater than about 30 degrees, the frequency and duration of habitable ice is considerably diminished, and the intervening dormancy periods, during which cosmic ray damage accumulates, are correspondingly longer. In all cases, the maximum dormancy period that must be survived by putative martian psychrophiles is at least an order of magnitude greater than the amount of time required to reduce terrestrial psychrophile spore viability by 10(-6) (similar to 7 x 10(4) years). Depending on the fate of high-obliquity polar ice, the maximum dormancy period can exceed 4 x 106 years, a factor of 60 longer than terrestrial psychrophile spore lifetimes. Habitability of martian ground ice is therefore dependent on putative martian psychrophiles developing robustness against GCR deactivation at least an order of magnitude greater than their terrestrial counterparts. Simulations of ground ice throughout the 65 degrees N-72 degrees N latitude range accessible to Phoenix suggest that higher-latitude ground ice has better habitability metrics, although the discrepancy is less than an order of magnitude for all metrics and across the entire latitude range. Published by Elsevier Inc. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Zent, A (reprint author), NASA, Ames Res Ctr, MS 245-3, Moffett Field, CA 94035 USA. EM aaron.p.zent@nasa.gov NR 63 TC 22 Z9 22 U1 0 U2 10 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 AUG PY 2008 VL 196 IS 2 BP 385 EP 408 DI 10.1016/j.icarus.2007.12.028 PG 24 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 331TK UT WOS:000258035300005 ER PT J AU Brown, AJ Byrne, S Tornabene, LL Roush, T AF Brown, Adrian J. Byrne, Shane Tornabene, Livio L. Roush, Ted TI Louth crater: Evolution of a layered water ice mound SO ICARUS LA English DT Article; Proceedings Paper CT 4th International Conference on Mars Polar Science and Exploration CY OCT 02-06, 2006 CL Davos, SWITZERLAND DE Mars; Mars, polar geology; ices, IR spectroscopy ID MARS; TEMPERATURES; ULTRAVIOLET; DEPOSITS; FEATURES; MODEL; DUST; POLE AB We report on observations made of the similar to 36 km diameter crater, Louth, in the north polar region of Mars (at 70 degrees N, 103.2 degrees E). High-resolution imagery from the instruments on the Mars Reconnaissance Orbiter (MRO) spacecraft has been used to map a 15 km diameter water ice deposit in the center of the crater. The water ice mound has surface features that include roughened ice textures and layering similar to that found in the North Polar Layered Deposits. Features we interpret as sastrugi and sand dunes show consistent wind patterns within Louth over recent time. CRISM spectra of the ice mound were modeled to derive quantitative estimates of water ice and contaminant abundance, and associated ice grain size information. These morphologic and spectral results are used to propose a stratigraphy for this deposit and adjoining sand dunes. Our results suggest the edge of the water ice mound is currently in retreat. (C) 2007 Elsevier Inc. All rights reserved. C1 [Brown, Adrian J.] SETI Inst, Mountain View, CA 94043 USA. [Brown, Adrian J.; Roush, Ted] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. [Byrne, Shane; Tornabene, Livio L.] Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. RP Brown, AJ (reprint author), SETI Inst, 515 N Whisman Rd, Mountain View, CA 94043 USA. EM abrown@seti.org RI Byrne, Shane/B-8104-2012 NR 25 TC 17 Z9 17 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 EI 1090-2643 J9 ICARUS JI Icarus PD AUG PY 2008 VL 196 IS 2 BP 433 EP 445 DI 10.1016/j.icarus.2007.11.023 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 331TK UT WOS:000258035300008 ER PT J AU Williams, KE Toon, OB Heldmann, JL Mckay, C Mellon, MT AF Williams, K. E. Toon, O. B. Heldmann, J. L. McKay, C. Mellon, M. T. TI Stability of mid-latitude snowpacks on Mars SO ICARUS LA English DT Article; Proceedings Paper CT 4th International Conference on Mars Polar Science and Exploratio CY OCT 02-06, 2006 CL Davos, SWITZERLAND DE ices; Mars, surface ID POTENTIAL FORMATION MECHANISMS; LIQUID WATER; MARTIAN GULLIES; VAPOR-PRESSURE; ICE; TEMPERATURES; CONSTRAINTS; SUBLIMATION; MODEL AB Christensen [2003. Nature 422, 45-48] suggested that runoff from melting snowpacks on martian slopes might be responsible for carving gullies. He also suggested that snowpacks currently exist on Mars, for example on the walls of Dao Valles (approximately 33 degrees S). Such snowpacks were presumably formed during the last obliquity cycle, which occurred about 70,000 years ago. In this paper we investigate a specific scenario under conditions we believe are favorable for snowpack melting. We model the rate at which a snowpack located at 33 degrees S on a poleward-facing slope sublimates and melts on Mars, as well as the temperature profile within the snowpack. Our model includes the energy and mass balance of a snowpack experiencing diurnal variations in insolation. Our results indicate that a dirty snowpack would quickly sublimate and melt under current martian climate conditions. For example a 1 m thick dusty snowpack of moderate density (550 kg/m(3)) and albedo (0.39) would sublimate in less than two seasons, producing a small amount of meltwater runoff. Similarly, a cleaner snowpack (albedo 0.53) would disappear in less than 9 seasons. These results suggest that the putative snowpack almost certainly could not have survived for 70,000 years. For most of the parameter settings snowpack interior temperatures at this latitude and slope do reach the melting point. Under most conditions melting occurs when the snowpack is less than 10 cm thick. The modeled snowpack will not melt if it is covered by a 1 cm dust lag. In general, these findings raise interesting possibilities regarding gully formation, but perhaps mostly during a past climate regime when snowfall was expected to have occurred. If there currently are exposed snowpacks on martian mid-latitude slopes, then these ice sheets cannot last long. Hence they might be time variable features on Mars and should be searched for. (C) 2008 Elsevier Inc. All rights reserved. C1 [Williams, K. E.; Toon, O. B.; Mellon, M. T.] Univ Colorado, LASP UCB 392, Dept Atmospher & Ocean Sci, Boulder, CO 80309 USA. [Heldmann, J. L.; McKay, C.] NASA, Ames Res Ctr, Div Space Sci & Astrobiol, Moffett Field, CA 94035 USA. RP Williams, KE (reprint author), Univ Colorado, LASP UCB 392, Dept Atmospher & Ocean Sci, Boulder, CO 80309 USA. EM kaj.williams@colorado.edu RI Mellon, Michael/C-3456-2016 NR 39 TC 31 Z9 31 U1 1 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 AUG PY 2008 VL 196 IS 2 BP 565 EP 577 DI 10.1016/j.icarus.2008.03.017 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 331TK UT WOS:000258035300017 ER PT J AU Leyrat, C Ferrari, C Charnoz, S Decriem, J Spilker, LJ Pilorz, S AF Leyrat, Cedric Ferrari, Cecile Charnoz, Sebastien Decriem, Judicael Spilker, Linda J. Pilorz, Stuart TI Spinning particles in Saturn's C ring from mid-infrared observations: Pre-Cassini mission results SO ICARUS LA English DT Article; Proceedings Paper CT 4th International Conference on Mars Polar Science and Exploration CY OCT 02-06, 2006 CL Davos, SWITZERLAND DE planetary rings; Saturn, rings; infrared observations; thermal histories; planetary dynamics ID DENSE PLANETARY RINGS; SELF-GRAVITY WAKES; INFRARED OBSERVATIONS; THERMAL OBSERVATIONS; SIZE DISTRIBUTION; SOLAR ELEVATION; MAIN RINGS; SIMULATIONS; EMISSION; ROTATION AB Saturn's C ring thermal emission has been observed in mid-infrared wavelengths, at three different epochs and solar phase angles, using ground based instruments (CFHT in 1999 and VLT/ESO in 2005) and the Infrared Radiometer Instrument Spectrometer (IRIS) onboard the Voyager I spacecraft in 1980. Azimuthal variations of temperature in the C ring's inner region, observed at several phase angles, have been analyzed using our new standard thermal model [Ferrari, C., Leyrat, C., 2006. Astron. Astrophys. 447, 745-760]. This model provides predicted ring temperatures for a monolayer ring composed of spinning icy spherical particles. We confirm the very low thermal inertia (on the order of 10 J m(-2) K-1 s(-1/2)) found previously by Ferrari et al. [Ferrari, C., Galdemard, P., Lagage, P.O., Pantin E., Quoirin, C., 2005. Astron. Astrophys. 441, 379-389] that reveals the very porous regolith at the surface of ring particles. We are able to explain both azimuthal variations of temperature and the strong asymmetry of the emission function between low and high phase angles. We show that large particles spinning almost synchronously might be present in the C ring to explain differences of temperature observed between low and high phase angle. Their cross section might represent about 45% of the total cross section. However, their numerical fraction is estimated to only similar to 0.1% of all particles. Thermal behavior of other particles can be modeled as isothermal behavior. This work provides an indirect estimation of the particle's rotation rate in Saturn's rings from observations. (C) 2008 Elsevier Inc. All rights reserved. C1 [Leyrat, Cedric; Spilker, Linda J.; Pilorz, Stuart] CALTECH, Jet Prop Lab, NASA, Pasadena, CA 91109 USA. [Ferrari, Cecile; Charnoz, Sebastien; Decriem, Judicael] Univ Paris 07, CEA Saclay, UMR AIM, F-91190 Paris, France. RP Leyrat, C (reprint author), CALTECH, Jet Prop Lab, NASA, 4800 Oak Grove Dr,M-S 230-205, Pasadena, CA 91109 USA. EM cedric.leyrat@jpl.nasa.gov RI Ferrari, Cecile/P-9735-2016 OI Ferrari, Cecile/0000-0001-5962-7439 NR 48 TC 12 Z9 12 U1 0 U2 1 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 AUG PY 2008 VL 196 IS 2 BP 625 EP 641 DI 10.1016/j.icarus.2008.03.005 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 331TK UT WOS:000258035300021 ER PT J AU Tobie, G Cadek, O Sotin, C AF Tobie, G. Cadek, O. Sotin, C. TI Solid tidal friction above a liquid water reservoir as the origin of the south pole hotspot on Enceladus SO ICARUS LA English DT Article; Proceedings Paper CT 4th International Conference on Mars Polar Science and Exploration CY OCT 02-06, 2006 CL Davos, SWITZERLAND DE Enceladus; ices; infrared observations; interiors; tides, solid body ID GLACIAL ISOSTATIC-ADJUSTMENT; ICE SHELL; INTERNAL STRUCTURE; SPHERICAL EARTH; HEAT-FLUX; EUROPA; VISCOSITY; DISSIPATION; CONVECTION; EVOLUTION AB Earth, Jupiter's moon Io and Saturn's tiny moon Enceladus are the only solid objects in the Solar System to be sufficiently geologically active for their internal heat to be detected by remote sensing. Interestingly, the endogenic activity on Enceladus is only located on a specific region at the south pole, from which jets of water vapor and ice particles have been observed [Spencer, J.R., and 9 colleagues, 2006. Science 311, 1401-1405; Porco, C.C., and 24 colleagues, 2006. Science 311, 1393-1401]. The current polar location of the thermal anomaly can possibly be explained by diapir-induced reorientation of the satellite [Nimmo, F., Pappalardo, R.T., 2006. Nature 441, 614-616], but the thermal anomaly triggering and the heat power required to sustain it over geological timescales remain problematic. Using a three-dimensional viscoelastic numerical model simulating the response of Enceladus to tidal forcing, we explore the effect of a low-viscosity anomaly in the ice shell, localized to the south polar region, on the tidal dissipation patterns. We demonstrate that only interior models with a liquid water layer at depth can explain the observed magnitude of dissipation rate and its particular location at the south pole. Moreover, we show that tidally-induced heat must be generated over a relatively broad region in the southern hemisphere, and it is then transferred toward the south pole where it is episodically released during relatively short resurfacing events. As large tidal dissipation and internal melting cannot be induced in the south polar region in the absence Of a pre-existing liquid decoupling layer, we propose that liquid water must have been present in the interior for a very long period of time, and possibly since the satellite formation. Owing to the orbital equilibrium requirement [Meyer, J., Wisdom, J., 2007. Icarus 188, 535-539], sustaining some liquid water at depth is impossible if heat is continuously emitted at a rate of 4-8 GW at the south pole. Based on that requirement, we propose that the current thermal emission is not in equilibrium with the heat production, and that the thermal emission rate is abnormally high at present time. Alternatively, continuous dissipation at a rate of 1-2 GW in the ice shell at the south pole should be sufficient to induce internal melting and it could sustain a layer of liquid water at depth over geologic timescales. (C) 2008 Elsevier Inc. All rights reserved. C1 [Tobie, G.; Sotin, C.] Univ Nantes Atlantique, Lab Planetol & Geodynam Nantes, F-44322 Nantes 03, France. [Tobie, G.; Sotin, C.] CNRS, UMR 6112, F-44322 Nantes 03, France. [Cadek, O.] Charles Univ Prague, Dept Geophys, Fac Math & Phys, CR-18000 Prague 8, Czech Republic. [Sotin, C.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Tobie, G (reprint author), Univ Nantes Atlantique, Lab Planetol & Geodynam Nantes, 2 Rue Houssiniere, F-44322 Nantes 03, France. EM gabriet.tobie@univ-nantes.fr RI Cadek, Ondrej/P-6527-2016 OI Cadek, Ondrej/0000-0001-8331-3093 NR 52 TC 74 Z9 75 U1 4 U2 27 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 AUG PY 2008 VL 196 IS 2 BP 642 EP 652 DI 10.1016/j.icarus.2008.03.008 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 331TK UT WOS:000258035300022 ER PT J AU Kory, CL Lambert, KM Acosta, RJ Nessel, JA AF Kory, Carol L. Lambert, Kevin M. Acosta, Roberto J. Nessel, James A. TI Prototype Antenna Elements for the Next-Generation TDRS Enhanced Multiple-Access Array SO IEEE ANTENNAS AND PROPAGATION MAGAZINE LA English DT Article DE Waveguide antennas; cup waveguide antennas; backfire antennas; satellite antennas; antennas; helical antennas; microwave antennas; corrugated horn antennas; orthomode transducer; polarization; polarizer ID SHORT-BACKFIRE ANTENNA AB This paper summarizes a study performed to produce prototype antenna elements for the next-generation enhanced Tracking and Data Relay Satellite Continuation (TDRS-C) multiple-access (MA) S-band phased-array antenna. Compared to the multiple-access antenna on the current class of TDRS, the enhanced multiple-access antenna requires elements that achieve greater on-axis gain, simultaneous circular polarization capability, and increased beamwidth. To demonstrate that array elements could be realized meeting these requirements, designs that were successful in simulation were fabricated and tested. These included a helical antenna; a novel short backfire antenna, excited with a circular waveguide (cup waveguide) with integrated polarizer and orthomode transducer (OMT); and a corrugated-horn antenna with integrated polarizer and OMT. The paper describes the design process for the novel elements, and compares measured and simulated results. It also compares the elements in terms of performance, size, and mass. C1 [Kory, Carol L.; Lambert, Kevin M.] NASA, Glenn Res Ctr, Analex Corp, Cleveland, OH 44135 USA. RP Kory, CL (reprint author), NASA, Glenn Res Ctr, Analex Corp, 21000 Brookpk Rd,MS GES AOS, Cleveland, OH 44135 USA. EM carol.l.kory@nasa.gov NR 12 TC 1 Z9 2 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 1045-9243 EI 1558-4143 J9 IEEE ANTENN PROPAG M JI IEEE Antennas Propag. Mag. PD AUG PY 2008 VL 50 IS 4 BP 72 EP 83 DI 10.1109/MAP.2008.4653664 PG 12 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA 360YA UT WOS:000260093500009 ER PT J AU Goebel, K Saha, B Saxena, A Celaya, JR Christophersen, JP AF Goebel, Kai Saha, Bhaskar Saxena, Abhinav Celaya, Jose R. Christophersen, Jon P. TI Prognostics in battery health management SO IEEE INSTRUMENTATION & MEASUREMENT MAGAZINE LA English DT Article; Proceedings Paper CT 43rd Annual IEEE AUTOTESTCON Conference CY SEP 08-11, 2008 CL Salt Lake City, UT SP IEEE Aerosp & Elect Syst Soc C1 [Goebel, Kai; Saxena, Abhinav] NASA Ames Res Ctr, Prognost Ctr Excellence, Adv Comp Sci Res Inst, Washington, DC USA. [Goebel, Kai] Gen Elect Global Res Ctr, Niskayuna, NY USA. [Christophersen, Jon P.] Idaho Natl Lab, Energy Storage & Transportat Syst Dept, Idaho Falls, ID USA. RP Goebel, K (reprint author), NASA Ames Res Ctr, Prognost Ctr Excellence, Adv Comp Sci Res Inst, Washington, DC USA. EM kai.goebel@nasa.gov NR 9 TC 99 Z9 107 U1 6 U2 26 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 1094-6969 EI 1941-0123 J9 IEEE INSTRU MEAS MAG JI IEEE Instrum. Meas. Mag. PD AUG PY 2008 VL 11 IS 4 BP 33 EP 40 DI 10.1109/MIM.2008.4579269 PG 8 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 331SI UT WOS:000258032500007 ER PT J AU Deal, WR Mei, XB Radisic, V Bayuk, B Fung, A Yoshida, W Liu, PH Uyeda, J Samoska, L Gaier, T Lai, R AF Deal, W. R. Mei, X. B. Radisic, V. Bayuk, B. Fung, A. Yoshida, W. Liu, P. H. Uyeda, J. Samoska, L. Gaier, T. Lai, R. TI A new sub-millimeter wave power amplifier topology using large transistors SO IEEE MICROWAVE AND WIRELESS COMPONENTS LETTERS LA English DT Article DE coplanar waveguide (CPW); high electron mobility transistor (HEMT); millimeter wave; monolithic microwave integrated circuit (MMIC); power amplifier (PA) AB In this letter, a new power amplifier topology is demonstrated which allows the use of large (120 mu m/transistors) at extremely high frequency. This is accomplished by using compact matching networks consisting of coplanar waveguide transmission lines and metal-insulator-metal capacitors to match each of the three amplifier stages. The resulting amplifier achieves a peak gain of 16.5 dB at 260 GHz. Power measurements indicate that the chip achieves >5.9 mW (unsaturated) of output power and 4% power added efficiency at a frequency of 270 GHz, where the output power is limited by the available source drive power. This power level from a single transistor represents a significant improvement at this frequency band. C1 [Deal, W. R.; Mei, X. B.; Radisic, V.; Bayuk, B.; Yoshida, W.; Liu, P. H.; Uyeda, J.; Lai, R.] Northrop Grumman Corp, Redondo Beach, CA 90278 USA. [Fung, A.; Samoska, L.; Gaier, T.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Deal, WR (reprint author), Northrop Grumman Corp, Redondo Beach, CA 90278 USA. EM william.deal@ngst.com NR 9 TC 10 Z9 10 U1 1 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 1531-1309 J9 IEEE MICROW WIREL CO JI IEEE Microw. Wirel. Compon. Lett. PD AUG PY 2008 VL 18 IS 8 BP 542 EP 544 DI 10.1109/LMWC.2008.2001017 PG 3 WC Engineering, Electrical & Electronic SC Engineering GA 336OB UT WOS:000258373400016 ER PT J AU Perez, R Lukash, JA AF Perez, Reinaldo Lukash, James A. TI Editorial special issue on aerospace electromagnetic compatibility SO IEEE TRANSACTIONS ON ELECTROMAGNETIC COMPATIBILITY LA English DT Editorial Material C1 [Perez, Reinaldo] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Lukash, James A.] Lockheed Missiles & Space Co Inc, Sunnyvale, CA 94089 USA. RP Perez, R (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0018-9375 J9 IEEE T ELECTROMAGN C JI IEEE Trans. Electromagn. Compat. PD AUG PY 2008 VL 50 IS 3 BP 453 EP 454 DI 10.1109/TEMC.2008.928498 PN 1 PG 2 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA 342YW UT WOS:000258820500001 ER PT J AU Perez, R AF Perez, Reinaldo TI Methods for spacecraft avionics protection against space radiation in the form of single-event transients SO IEEE TRANSACTIONS ON ELECTROMAGNETIC COMPATIBILITY LA English DT Article DE avionics; field-programmable gate arrays (FPGAs); single-event transients; spacecraft; space radiation AB This paper presents a design philosophy for protecting spacecraft avionics from the effects of single-event transients caused by high-energetic charged particles in the space environment. The design philosophy has resulted in a proven concept over the many years of actual implementation in real avionics in real space missions. Only an overview of this design philosophy is presented. The paper first addresses the science of the space environment as it relates to high-energy charged particles. It includes the derivations of important parameters in high-energy particle physics as it applies to interactions with semiconductor electronic in component integrated circuits. The paper then transitions to explore some general methodologies widely used in the industry to control the damaging effects of single-event transients caused by the space environment. The paper then shifts emphasis to the main subject of design methods and philosophies, with examples of how spacecraft avionics can be designed and built with a certain level of immunity against the possible catastrophic effects of single-event transients. These design principles are presented briefly, but with enough detail to provide a general overview. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Perez, R (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM reinaldo.j.perez@jpl.nasa.gov NR 10 TC 1 Z9 1 U1 1 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0018-9375 J9 IEEE T ELECTROMAGN C JI IEEE Trans. Electromagn. Compat. PD AUG PY 2008 VL 50 IS 3 BP 455 EP 465 DI 10.1109/TEMC.2008.927735 PN 1 PG 11 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA 342YW UT WOS:000258820500002 ER PT J AU Scully, RC AF Scully, R. C. TI Predicted Ku-band attenuation by twisted nonshielded cable and twisted shielded, controlled impedance cable SO IEEE TRANSACTIONS ON ELECTROMAGNETIC COMPATIBILITY LA English DT Article DE attenuation; electromagnetic coupling; traveling wave antennas (TWAs); twisted pair cables AB Both the Space Shuttle and the International Space Station utilize Kurtz-under band (Ku-band) systems for communications with the tracking and data relay satellite system. Knowledge of the extent and nature of the field to wire coupling in this operating frequency range is thus necessary to facilitate proper shielding and circuit design for the mitigation of radio-frequency interference with pyrotechnics and other noncommunications-related circuits and subsystems. To that end, this analysis will address the expected common-mode attenuation of twisted non-shielded cable, and twisted shielded, controlled impedance cable, mounted above a conducting ground plane and exposed to Ku-band radiation from nearby communications link antennas. Coupling calculations are performed by treating the cabling as forming a traveling wave antenna above a ground plane. The maximum receiving aperture of this configuration is determined for each cable type, and from this, a maximum coupled power. To facilitate calculation of the maximum receiving aperture, the attenuation constant for each type of cabling is determined from available data, and from treatment of the wiring as either a connected pair or as a single wire above a ground plane. The resulting coupled power at the frequencies of interest for each type of cable is calculated as a final result. C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. RP Scully, RC (reprint author), NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. EM robert.c.scully@nasa.gov NR 6 TC 0 Z9 0 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0018-9375 J9 IEEE T ELECTROMAGN C JI IEEE Trans. Electromagn. Compat. PD AUG PY 2008 VL 50 IS 3 BP 542 EP 546 DI 10.1109/TEMC.2008.927734 PN 1 PG 5 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA 342YW UT WOS:000258820500012 ER PT J AU Sun, WB Lin, B Hu, YX Wang, ZH Fu, YF Feng, Q Yang, P AF Sun, Wenbo Lin, Bing Hu, Yongxiang Wang, Zhenhui Fu, Yunfei Feng, Qian Yang, Ping TI Side-face effect of a dielectric strip on its optical properties SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article DE finite-difference time domain (FDTD); scattering; side-face effect; strip ID TIME-DOMAIN SOLUTION; PERFECTLY MATCHED LAYER; LIGHT-SCATTERING; ICE CRYSTALS; ABSORBING MEDIUM; CIRRUS CLOUDS; ABSORPTION; PARTICLES; CYLINDER; COLUMNS AB Light scattering by horizontally oriented platelike particles under normal incidence, such as ice plates or tree leaves under spaceborne lidar or radar waves, needs to be investigated for remote sensing of cirrus clouds or vegetation canopies. The solutions from the conventional geometrical ray tracing method for the scattering of electromagnetic waves by these particles are quite inaccurate because of the singularity problem that is inherent to this method. The scattering properties of large horizontally oriented platelike particles are usually approximated by using physical optics or electromagnetic wave theory while ignoring the side-face effect of the plates. In this paper, to examine the effect of side faces on light scattering by platelike particles, a 2-D finite-difference time-domain technique is applied to calculate light scattering by horizontally oriented ice and leaf strips under normal or quasi-normal incidence. It is found that for moderate-sized strips, the side faces of the particles scatter a significant amount of energy, resulting in strong maxima in the scattering phase function at certain scattering angles. By ignoring the effect of side faces, the scattering phase functions derived from electromagnetic wave theory have significant errors for small or moderate-sized strips. However, the ratio of the amount of energy scattered by the side faces to the total scattered energy decreases with the increase of strip width. When the size parameter of the strip is in the limit of geometric optics, the side-face effect is reduced to a negligible amount. However, even in this case, the polarization degrees from the approximation solutions of physical optics or electromagnetic wave theory ignoring the side-face effect still have large errors. C1 [Sun, Wenbo] Hampton Univ, Ctr Atmospher Sci, Hampton, VA 23668 USA. [Sun, Wenbo; Lin, Bing; Hu, Yongxiang] NASA, Langley Res Ctr, Hampton, VA 23681 USA. [Wang, Zhenhui] Nanjing Univ Informat Sci & Technol, Sch Remote Sensing, Nanjing 210044, Peoples R China. [Fu, Yunfei] Univ Sci & Technol China, Sch Earth & Space Sci, Hefei 230026, Peoples R China. [Feng, Qian; Yang, Ping] Texas A&M Univ, Dept Atmospher Sci, College Stn, TX 77843 USA. RP Sun, WB (reprint author), Hampton Univ, Ctr Atmospher Sci, Hampton, VA 23668 USA. EM wenbo.sun-1@nasa.gov RI Yang, Ping/B-4590-2011; Hu, Yongxiang/K-4426-2012 FU National Institute of Aerospace's [NCC-1-02043] FX Manuscript received November 9, 2007; revised December 17, 2007. This work was supported by a grant awarded under the National Institute of Aerospace's prime Contract NCC-1-02043. NR 29 TC 2 Z9 2 U1 0 U2 3 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 AUG PY 2008 VL 46 IS 8 BP 2337 EP 2344 DI 10.1109/TGRS.2008.916984 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 338GN UT WOS:000258494500016 ER PT J AU Joseph, AT van der Velde, R O'Neill, PE Lang, RH Gish, T AF Joseph, Alicia T. van der Velde, Rogler O'Neill, Peggy E. Lang, Roger H. Gish, Tim TI Soil moisture retrieval during a corn growth cycle using L-band (1.6 GHz) radar observations SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article DE field campaign; radar observations; remote sensing; soil moisture retrieval ID LAND-SURFACE PARAMETERS; ERS WIND SCATTEROMETER; LEAF-AREA INDEX; HYDROLOGY EXPERIMENT; MICROWAVE EMISSION; SCATTERING MODEL; X-BANDS; BACKSCATTERING; VEGETATION; CANOPY AB This paper reports on the retrieval of soil moisture from dual-polarized L-band (1.6 GHz) radar observations acquired at view angles of 15 degrees, 35 degrees, and 55 degrees, which were collected during a field campaign covering a corn growth cycle in 2002. The applied soil moisture retrieval algorithm includes a surface roughness and vegetation correction and could potentially be implemented as an operational global soil moisture retrieval algorithm. The surface roughness parameterization is obtained through inversion of the Integral Equation Method (IEM) from dual-polarized (HH and VV) radar observations acquired under nearly bare soil conditions. The vegetation correction is based on the relationship found between the ratio of modeled bare soil scattering contribution and observed backscatter coefficient (sigma(soil)/sigma(obs)) and vegetation water content (W). Validation of the retrieval algorithm against ground measurements shows that the top 5-cm soil moisture can be estimated with an accuracy between 0.033 and 0.064 cm(3). cm(-3), depending on the view angle and polarization. C1 [Joseph, Alicia T.; O'Neill, Peggy E.] NASA, Goddard Space Flight Ctr, Hydrol Sci Branch, Hydrospher & Biospher Sci Lab, Greenbelt, MD 20771 USA. [van der Velde, Rogler] Int Inst Geoinformat Sci & Earth Observat, NL-7500 AA Enschede, Netherlands. [Lang, Roger H.] George Washington Univ, Dept Elect & Comp Engn, Washington, DC 20052 USA. [Gish, Tim] USDA ARS, Hydrol & Remote Sensing Lab, Beltsville, MD 20705 USA. RP Joseph, AT (reprint author), NASA, Goddard Space Flight Ctr, Hydrol Sci Branch, Hydrospher & Biospher Sci Lab, Greenbelt, MD 20771 USA. EM Alicia.T.Joseph@nasa.gov; velde@itc.nl; Peggy.E.ONeill@nasa.gov; lang@gwu.edu; tgish@hydrolab.arsusda.gov RI O'Neill, Peggy/D-2904-2013; van der Velde, Rogier /K-8623-2013 OI van der Velde, Rogier /0000-0003-2157-4110 NR 41 TC 26 Z9 28 U1 0 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 AUG PY 2008 VL 46 IS 8 BP 2365 EP 2374 DI 10.1109/TGRS.2008.917214 PG 10 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA 338GN UT WOS:000258494500019 ER PT J AU Epp, LW Hoppe, DJ Khan, AR Stride, SL AF Epp, Larry W. Hoppe, Daniel J. Khan, Abdur R. Stride, Scot L. TI A high-power Ka-band (31-36 GHz) solid-state amplifier based on low-loss corporate waveguide combining SO IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES LA English DT Article DE amplifiers; dielectric-loaded waveguides; high-power Ka-band; power combiners; solid state ID QUASI-OPTICAL AMPLIFIER; CIRCUIT; DESIGN AB A method of using low-loss waveguide septum combiners is developed into a high-power Ka-band (31-36 GHz) amplifier producing >50 W at 33 GHz (Ka-band) using 32 low-power (<2 W) solid-state amplifier modules. By using low-loss waveguide combining and a packaged monolithic microwave integrated circuit with a low-loss microstrip-to-waveguide launcher, the output loss is minimized, allowing for the overall power-combining efficiency to remain high, >80% (average insertion loss of combiner <0.7 dB and average insertion loss of launcher <0.3 dB) over 31-36 GHz. In the past, lower power-combining efficiencies have limited the number of modules that can be combined at Ka-band, and hence, have limited the power output. The approach demonstrated in this paper, with high power-combining efficiency, allows a very large number (32) of solid-state amplifier modules to be combined to produce high powers. Greater than 50 W was demonstrated with low power modules, but even higher powers >120 W are possible. The current approach is based on corporate combining, using low-loss waveguide septum combiners that provide isolation, maintaining the true graceful degradation of a modular solid-state amplifier system. C1 [Epp, Larry W.; Hoppe, Daniel J.; Khan, Abdur R.; Stride, Scot L.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Epp, LW (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Larry.W.Epp@jpl.nasa.gov; Daniel.Hoppe@jpl.nasa.gov; Abdur.R.Khan@jpl.nasa.gov; Scot.L.Stride@jpl.nasa.gov FU National Aeronautics and Space Administration (NASA) FX This work was supported by the National Aeronautics and Space Administration (NASA) under a contract funded through the Internal Research and Technology Development Program. NR 29 TC 25 Z9 31 U1 1 U2 10 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0018-9480 J9 IEEE T MICROW THEORY JI IEEE Trans. Microw. Theory Tech. PD AUG PY 2008 VL 56 IS 8 BP 1899 EP 1908 DI 10.1109/TMTT.2008.927299 PG 10 WC Engineering, Electrical & Electronic SC Engineering GA 338JP UT WOS:000258504300016 ER PT J AU Bourdarie, S Xapsos, M AF Bourdarie, Sebastien Xapsos, Michael TI The Near-Earth Space Radiation Environment SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 9th European Conference Radiation and Its Effects on Components and Systems CY SEP 10-14, 2007 CL Deauville, FRANCE DE Galactic cosmic rays; solar particle event; trapped electrons; trapped protons ID SELF-ORGANIZED CRITICALITY; PROTON EVENT FLUENCES; SOLAR PARTICLE EVENTS; COSMIC-RAY EVENTS; HEAVY-ION MODEL; PROBABILITY MODEL; PEAK FLUXES; RELATIVISTIC ELECTRONS; DOSE FLUCTUATIONS; GEOMAGNETIC-FIELD AB The effects of the space radiation environment on spacecraft systems and instruments are significant design considerations for space missions. Astronaut exposure is a serious concern for manned missions. In order to meet these challenges and have reliable, cost-effective designs, the radiation environment must be understood and accurately modeled. The nature of the environment varies greatly between low earth orbits and higher earth orbits. There are both short-term and long-term variations with the phase of the solar cycle. In this paper we concentrate mainly on charged particle radiations in the near-Earth region. Descriptions of the radiation belts and particles of solar and cosmic origin are reviewed. An overview of the traditional models is presented accompanied by their application areas and limitations. This is followed by discussion of some recent model developments. C1 [Bourdarie, Sebastien] Off Natl Etud & Rech Aerosp, Space Environm Dept, F-31000 Toulouse, France. [Xapsos, Michael] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Bourdarie, S (reprint author), Off Natl Etud & Rech Aerosp, Space Environm Dept, F-31000 Toulouse, France. EM sebastien.bourdarie@onecert.fr; michael.a.xapsos@nasa.gov NR 101 TC 35 Z9 35 U1 0 U2 18 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 AUG PY 2008 VL 55 IS 4 BP 1810 EP 1832 DI 10.1109/TNS.2008.2001409 PN 1 PG 23 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 358EI UT WOS:000259899500002 ER PT J AU Johnston, AH Rax, BG Thorbourn, D AF Johnston, A. H. Rax, B. G. Thorbourn, D. TI Total Dose Effects in Op-Amps With Compensated Input Stages SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 9th European Conference Radiation and Its Effects on Components and Systems CY SEP 10-14, 2007 CL Deauville, FRANCE DE Hardness assurance; operational amplifier; space radiation effects; total dose ID LINEAR INTEGRATED-CIRCUITS; IONIZING-RADIATION; DEGRADATION; DEVICES AB This paper discusses total dose damage in operational amplifiers with compensated input stages. The impact of this design approach on unit-to-unit variability of radiation damage is examined, along with hardness assurance methods that can be used to bound the radiation behavior. Data is included for an unusually large sample (100 devices) of one device type. Half of those devices were subjected to burn-in before irradiation to investigate the effect of burn-in on radiation response. C1 [Johnston, A. H.; Rax, B. G.; Thorbourn, D.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Johnston, AH (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM allan.h.johnston@jpl.nasa.gov NR 16 TC 2 Z9 2 U1 1 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 AUG PY 2008 VL 55 IS 4 BP 1953 EP 1959 DI 10.1109/TNS.2008.2000889 PN 1 PG 7 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 358EI UT WOS:000259899500010 ER PT J AU Buchner, S McMorrow, D Bernard, M Roche, N Dusseau, L AF Buchner, Stephen McMorrow, Dale Bernard, Muriel Roche, Nicolas Dusseau, Laurent TI Total Dose Effects on Error Rates in Linear Bipolar Systems SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 9th European Conference Radiation and Its Effects on Components and Systems CY SEP 10-14, 2007 CL Deauville, FRANCE DE Bipolar circuit; error rate; single event transient; total dose ID SINGLE-EVENT TRANSIENTS; CIRCUITS AB The shapes of single event transients in linear bipolar circuits are distorted by exposure to total ionizing dose radiation. Some transients become broader and others become narrower. Such distortions may affect the Single Event Transient (SET) system error rates in a radiation environment. If the transients are broadened by total ionizing dose (TID) exposure, the error rate could increase during the course of a mission, a possibility that has implications for hardness assurance. C1 [Buchner, Stephen] NASA, Goddard Space Flight Ctr, Perot Syst Govt Serv, Greenbelt, MD 20771 USA. [McMorrow, Dale] USN, Res Lab, Washington, DC 20375 USA. [Bernard, Muriel; Roche, Nicolas; Dusseau, Laurent] Univ Montpellier 2, F-34095 Montpellier, France. RP Buchner, S (reprint author), NASA, Goddard Space Flight Ctr, Perot Syst Govt Serv, Greenbelt, MD 20771 USA. EM sbuchner@pop500.gsfc.nasa.gov; mcmorrow@ccs.nrl.navy.mil; bernard@ies.univ-montp2.fr; nicolas.roche@ies.univ-montp2.fr; dusseau@ies.univ-montp2.fr NR 8 TC 15 Z9 15 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 AUG PY 2008 VL 55 IS 4 BP 2055 EP 2062 DI 10.1109/TNS.2008.916061 PN 1 PG 8 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 358EI UT WOS:000259899500024 ER PT J AU Label, KA Ladbury, RL Cohn, LM Oldham, TR AF LaBel, Kenneth A. Ladbury, Ray L. Cohn, Lewis M. Oldham, Timothy R. TI Radiation Test Challenges for Scaled Commercial Memories SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 9th European Conference Radiation and Its Effects on Components and Systems CY SEP 10-14, 2007 CL Deauville, FRANCE DE CMOS; radiation effects; commercial memories ID HEAVY-ION; SEE; TECHNOLOGY AB As sub-100 mn CMOS technologies gather interest, the radiation effects performance of these technologies provide a significant challenge. In this paper, we shall discuss the radiation testing challenges as related to commercial memory devices. The focus will be on complex test and failure modes emerging in state-of-the-art Flash non-volatile memories (NVMs) and synchronous dynamic random access memories (SDRAMs), which are volatile. Due to their very high bit density, these device types are highly desirable for use in the natural space environment. In this paper, we shall discuss these devices with emphasis on considerations for test and qualification methods required. C1 [LaBel, Kenneth A.; Ladbury, Ray L.; Oldham, Timothy R.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Cohn, Lewis M.] Def Threat Reduct Agcy, Ft Belvoir, VA 22060 USA. RP Label, KA (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. EM Kenneth.A.LaBel@nasa.gov NR 21 TC 9 Z9 10 U1 0 U2 7 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 AUG PY 2008 VL 55 IS 4 BP 2174 EP 2180 DI 10.1109/TNS.2008.2001481 PN 1 PG 7 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 358EI UT WOS:000259899500041 ER PT J AU Berg, M Poivey, C Petrick, D Espinosa, D Lesea, A LaBel, KA Friendlich, M Kim, H Phan, A AF Berg, Melanie Poivey, C. Petrick, D. Espinosa, D. Lesea, Austin LaBel, K. A. Friendlich, M. Kim, H. Phan, Anthony TI Effectiveness of Internal Versus External SEU Scrubbing Mitigation Strategies in a Xilinx FPGA: Design, Test, and Analysis SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article; Proceedings Paper CT 9th European Conference Radiation and Its Effects on Components and Systems CY SEP 10-14, 2007 CL Deauville, FRANCE DE Field programmable gate array (FPGA); reconfiguration; scrubbing; Xilinx AB A comparison of two scrubbing mitigation schemes for Xilinx field programmable gate array devices is presented. The design of the scrubbers is briefly discussed along with an examination of mitigation limitations. Heavy ion data are then presented and analyzed. C1 [Berg, Melanie; Poivey, C.; Friendlich, M.; Kim, H.; Phan, Anthony] NASA, Goddard Space Flight Ctr, MEI Technol Support, Greenbelt, MD 20771 USA. [Lesea, Austin] Xilinx Inc, San Jose, CA 95124 USA. RP Berg, M (reprint author), NASA, Goddard Space Flight Ctr, MEI Technol Support, Greenbelt, MD 20771 USA. EM mdberg@pop500.gsfc.nasa.gov; cpoivey@pop500.gsfc.nasa.gov; dpetrick@gsfc.gov; austin.lesea@xilinx.com; hkim@pop500.gsfc.nasa.gov NR 17 TC 56 Z9 58 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 AUG PY 2008 VL 55 IS 4 BP 2259 EP 2266 DI 10.1109/TNS.2008.2001422 PN 1 PG 8 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 358EI UT WOS:000259899500054 ER PT J AU Scheick, L Edmonds, L Selva, L Chen, Y AF Scheick, Leif Edmonds, Larry Selva, Luis Chen, Yuan TI Current Leakage Evolution in Partially Gate Ruptured Power MOSFETs SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article DE Avalanche breakdown; power MOSFET; SEGR; thermal runaway ID MAXIMUM DIELECTRIC STRENGTH; OXIDE RELIABILITY; DEVICES; FILMS AB It has been observed that power MOSFETs can experience an SEGR and continue to function with altered parameters. We propose that there are three different types of SEGR modes; the micro-break, the thermal runaway, and the avalanche breakdown. Data that demonstrates these stages of device failure are presented as well as a proposed model for the micro-break. Brief discussions of the other modes, based on analysis combined with our interpretations of the older literature, are also given. C1 [Scheick, Leif; Edmonds, Larry; Selva, Luis; Chen, Yuan] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Scheick, L (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM leif.scheick@jpl.nasa.gov NR 13 TC 6 Z9 6 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 AUG PY 2008 VL 55 IS 4 BP 2366 EP 2375 DI 10.1109/TNS.2008.2001008 PN 2 PG 10 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 358EJ UT WOS:000259899600012 ER PT J AU Druyan, LA Fulakeza, M Lonergan, P AF Druyan, Leonard A. Fulakeza, Matthew Lonergan, Patrick TI The impact of vertical resolution on regional model simulation of the west African summer monsoon SO INTERNATIONAL JOURNAL OF CLIMATOLOGY LA English DT Article DE west African monsoon; regional climate model; African easterly waves ID WAVE DISTURBANCES; EASTERLY WAVES; CLIMATE; ATLANTIC; CONVECTION; PARAMETERIZATION; PRECIPITATION; RAINFALL; GCM AB The RM3 regional climate model is used to simulate the west African summer monsson for six June-September seasons using NCEP reanalysis data for lateral boundary forcing. The study compares the performance of the previously published 16-level verison with a newly tested 28-level version, both running on a horizontal grid with 0.5 degrees spacing, in order to determine what improvements in simulations are achieved by increased vertical resolution. Comparisons between the performances include diagnostics of seasonal mean precipitation rates and circulation, vertical profiles of cumulus heating rates, frequencies of shallow and deep convection and diagnostics related to transient African easterly waves (AEWs). The characteristics of a composite AEW simulated at both Vertical resolutions are presented. Results show that the most significant impact of increasing the vertical resolution is stronger circulation. stronger vertical wind shear and higher amplitude AEWs. The simulations With higher vertical resolution also achieve higher peaks of cumulus latent heating rates. Spatial-temporal correlations between simulated daily 700 mb meridional winds versus corresponding NCEP reanalysis data and simulated daily precipitation versus estimates from the Tropical rainfall Measurement (TRMM) archive were equally high at both vertical resolutions. Copyright (C) 2007 Royal Meteorological Society. C1 [Druyan, Leonard A.; Fulakeza, Matthew; Lonergan, Patrick] Columbia Univ, Ctr Climate Syst Res, Earth Inst, New York, NY 10025 USA. [Druyan, Leonard A.; Fulakeza, Matthew; Lonergan, Patrick] NASA, Goddard Inst Space Studies, New York, NY 10025 USA. RP Druyan, LA (reprint author), Columbia Univ, Ctr Climate Syst Res, Earth Inst, 2880 Broadway, New York, NY 10025 USA. EM LDruyan@giss.nasa.gov FU National Science Foundation [ATM-0354589, ATM-0652518]; NASA [NNX07AI93G]; NASA Climate and Earth Observing System Programs FX This research was supported by National Science Foundation grants ATM-0354589. ATM-0652518, NASA grant NNX07AI93G and by the NASA Climate and Earth Observing System Programs. TRMM data used in this study were acquired using the GES-DISC Interactive Online Visualization ANd aNalysis Infrastructure (Giovanni) as part of the NASA's Goddard Earth Sciences (GES) Data and Information Services Center (DISC). NCEP reanalysis data used in this study were obtained online from the NOAA/Earth System Research Laboratory (Physical Sciences Division). The authors acknowledge helpful discussions regarding Cumulus heating rates with Dr A. Del Genio, Dr M-S. Yao and Dr Y-H. Chen. The authors also acknowledge the very Constructive suggestions of two anonymous reviewers that significantly contributed to the final paper. NR 29 TC 22 Z9 22 U1 0 U2 1 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0899-8418 J9 INT J CLIMATOL JI Int. J. Climatol. PD AUG PY 2008 VL 28 IS 10 BP 1293 EP 1314 DI 10.1002/joc.1636 PG 22 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 344LW UT WOS:000258929700003 ER PT J AU Finke, N Jorgensen, BB AF Finke, Niko Jorgensen, Bo Barker TI Response of fermentation and sulfate reduction to experimental temperature changes in temperate and Arctic marine sediments SO ISME JOURNAL LA English DT Article DE hydrogen; marine sediments; sulfate reduction; temperature response; volatile fatty acids ID ORGANIC-MATTER; REDUCING BACTERIA; HYDROGEN CONCENTRATIONS; CARBON DEGRADATION; AQUATIC SEDIMENTS; DEPENDENCE; GROWTH; ACETATE; BASIN; RATES AB Anaerobic degradation of organic material generally proceeds through a sequence of steps, including polymer hydrolysis, fermentation and respiration or methanogenesis. The intermediates, such as volatile fatty acids (VFA) or H-2, are generally maintained at low concentration, showing a close coupling of the terminal oxidation to fermentation. We exposed marine sediments to extreme temperature perturbations to study the nature and robustness of this coupling. Bacterial sulfate reduction and its dependence on fermentation were studied experimentally over a broad temperature range of -0.3 to 40 degrees C in sediments from temperate and permanently cold environments. In an Arctic sediment from Svalbard, the apparent optimum temperature for sulfate reduction decreased with prolonged incubation, whereas sulfate reduction rates increased. In a temperate sediment from the North Sea, the apparent optimum temperature was higher and did not change with incubation time. Up to a critical temperature, the concentrations of VFA remained low, < 3 mu M for acetate and mu 1 mu M for the other VFA, the H-2 concentration showed thermodynamic control by sulfate-reducing bacteria, revealing a close coupling of fermentation and sulfate reduction. Above the critical temperature, the concentrations of VFA and H-2 increased transiently by 100-1000-fold. According to the different in situ temperatures of the samples, the critical temperature was lower for sediments from the Arctic than from the North Sea. The H-2 concentrations decreased again upon prolonged incubation to values typical for sulfate-depleted methanogenic sediments. This suggests that fermentative bacteria and methanogenic archaea in both sediments tolerated higher temperatures than the sulfate-reducing community. C1 [Finke, Niko; Jorgensen, Bo Barker] Max Planck Inst Marine Microbiol, Dept Biochem, Bremen, Germany. RP Finke, N (reprint author), NASA, Ames Res Ctr, Exobiol Branch, Mailstop 239-4, Moffett Field, CA 94035 USA. EM nfinke@web.de RI Jorgensen, Bo/C-2214-2013 OI Jorgensen, Bo/0000-0001-9398-8027 NR 49 TC 27 Z9 27 U1 1 U2 15 PU NATURE PUBLISHING GROUP PI NEW YORK PA 75 VARICK STREET, 9TH FLOOR, NEW YORK, NY 10013-1917 USA SN 1751-7362 J9 ISME J JI ISME J. PD AUG PY 2008 VL 2 IS 8 BP 815 EP 829 DI 10.1038/ismej.2008.20 PG 15 WC Ecology; Microbiology SC Environmental Sciences & Ecology; Microbiology GA 335CF UT WOS:000258267700004 PM 18309360 ER PT J AU Johnson, L Gilbert, P AF Johnson, Les Gilbert, Paul TI NASA's Discovery program: Moving toward the edge (of the solar system) SO JBIS-JOURNAL OF THE BRITISH INTERPLANETARY SOCIETY LA English DT Article; Proceedings Paper CT 5th IAA Symposium on Realistic Near-Term Advanced Scientific Space Missions CY JUL 02-04, 2007 CL Aosta, ITALY SP IAA DE Dawn mission; Kepler mission; Discovery program; extraterrestrial life AB The goal of NASA's Discovery program is to launch many smaller missions with fast development times to increase our understanding of the solar system. Discovery missions are solicited from the broad planetary science community approximately every 2 years. Active missions within the program include several with direct scientific or engineering connections to potential future missions to the edge of the solar system and beyond. The Dawn mission, launched in late 2007, uses ion drive as its primary propulsion system. Ion propulsion is one of only two technologies that appear feasible for early interstellar precursor missions with practical flight times. The Kepler mission will explore the structure and diversity of extrasolar planetary systems, with an emphasis on the detection of Earth-size planets around other stars. Kepler will survey nearby solar systems searching for planets that may fall within the 'habitable zone,' a region surrounding a star within which liquid water may exist on a planet's surface - an essential ingredient for life as we know it. In addition, the first New Frontiers mission is the New Horizons mission to Pluto, which will explore this 38-AU distant dwarf planet and potentially some Kuiper Belt objects beyond. C1 [Johnson, Les; Gilbert, Paul] NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Johnson, L (reprint author), NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. EM c.les.johnson@nasa.gov NR 4 TC 0 Z9 0 U1 3 U2 6 PU BRITISH INTERPLANETARY SOC PI LONDON PA 27-29 S LAMBETH RD, LONDON SW8 1SZ, ENGLAND SN 0007-084X J9 JBIS-J BRIT INTERPLA JI JBIS-J. Br. Interplanet. Soc. PD AUG PY 2008 VL 61 IS 8 BP 300 EP 303 PG 4 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary SC Engineering; Astronomy & Astrophysics; Geology GA 325QL UT WOS:000257603300005 ER PT J AU Wolff, DB Fisher, BL AF Wolff, David B. Fisher, Brad L. TI Comparisons of instantaneous TRMM ground validation and satellite rain-rate estimates at different spatial scales SO JOURNAL OF APPLIED METEOROLOGY AND CLIMATOLOGY LA English DT Article ID MEASURING MISSION TRMM; TROPICAL RAINFALL; PRECIPITATION RADAR; STOCHASTIC-MODEL; SAMPLING ERROR; PROFILING ALGORITHM; AMSR-E; SSM/I; UNCERTAINTIES; RETRIEVAL AB This study provides a comprehensive intercomparison of instantaneous rain rates observed by the two rain sensors aboard the Tropical Rainfall Measuring Mission (TRMM) satellite with ground data from two regional sites established for long-term ground validation: Kwajalein Atoll and Melbourne, Florida. The satellite rain algorithms utilize remote observations of precipitation collected by the TRMM Microwave Imager (TMI) and the Precipitation Radar ( PR) aboard the TRMM satellite. Three standard level II rain products are generated from operational applications of the TMI, PR, and combined (COM) rain algorithms using rain information collected from the TMI and the PR along the orbital track of the TRMM satellite. In the first part of the study, 0.5 degrees x 0.5 degrees instantaneous rain rates obtained from the TRMM 3G68 product were analyzed and compared to instantaneous Ground Validation (GV) program rain rates gridded at a scale of 0.5 degrees x 0.5 degrees. In the second part of the study, TMI, PR, COM, and GV rain rates were spatiotemporally matched and averaged at the scale of the TMI footprint (similar to 150 km(2)). This study covered a 6-yr period (1999-2004) and consisted of over 50 000 footprints for each GV site. In the first analysis, the results showed that all of the respective rain-rate estimates agree well, with some exceptions. The more salient differences were associated with heavy rain events in which one or more of the algorithms failed to properly retrieve these extreme events. Also, it appears that there is a preferred mode of precipitation for TMI rain rates at or near 2 mm h(-1) over the ocean. This mode was noted over ocean areas of Kwajalein and Melbourne and has been observed in TRMM tropical-global ocean areas as well. C1 [Wolff, David B.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Sci Syst & Appl Inc, Lanham, MD USA. RP Wolff, DB (reprint author), NASA, Goddard Space Flight Ctr, Code 613-1, Greenbelt, MD 20771 USA. EM wolff@radar.gsfc.nasa.gov RI Wolff, David/H-5502-2012 FU NASA [NNG07EJ50C] FX This work 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 support of this effort. We also appreciate the support staff of the TSVO, including David Makofski, Bart Kelley, David Marks, David Silberstein, and Jason Pippitt. NR 36 TC 42 Z9 43 U1 0 U2 10 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 AUG PY 2008 VL 47 IS 8 BP 2215 EP 2237 DI 10.1175/2008JAMC1875.1 PG 23 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 338EN UT WOS:000258488600010 ER PT J AU Koch, SE Flamant, C Wilson, JW Gentry, BM Jamison, BD AF Koch, Steven E. Flamant, Cyrille Wilson, James W. Gentry, Bruce M. Jamison, Brian D. TI An atmospheric soliton observed with Doppler radar, differential absorption lidar, and a molecular Doppler lidar SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article; Proceedings Paper CT 7th International Symposium on Tropospheric Profiling CY JUN, 2006 CL Boulder, CO ID MESOSCALE GRAVITY-WAVE; NUMERICAL-SIMULATION; BOUNDARY-LAYER; WATER-VAPOR; INTERNAL BORES; LEANDRE-II; TROPOSPHERE; ENVIRONMENTS; INITIATION; CURRENTS AB Airborne Leandre II differential absorption lidar (DIAL), S-band dual-polarization Doppler radar (S-Pol), and Goddard Lidar Observatory for Winds (GLOW) Doppler lidar data are used, in conjunction with surface mesonet and special sounding data, to derive the structure and dynamics of a bore and associated solitary wave train (soliton) that were generated in southwestern Kansas during the International H2O Project (IHOP_ 2002). Vertical cross sections of S-Pol reflectivity, S-Pol radial velocity, and DIAL water vapor mixing ratio show a stunning amplitude-ordered train of trapped solitary waves. DIAL data reveal that the leading wave in the soliton increasingly flattened with time as the soliton dissipated. A method is developed for using the GLOW Doppler winds to obtain the complex two-dimensional vertical circulation accompanying the dissipating soliton. The results show multiple circulations identical in number to the oscillations seen in the S-Pol and DIAL data. The leading updraft occurred precisely at the time that the bore passed over the GLOW facility, as well as when the photon count values suddenly ramped up (suggesting lifting of the low-level inversion by the bore). Additional evidence in support of the validity of the results is provided by the fact that layer displacements computed using the derived vertical motions agree well with those implied by the changes in height of the DIAL mixing ratio surfaces. The depth and speed of propagation of the bore seen in the DIAL and surface mesoanalyses were shown to be consistent with the predictions from bore hydraulic theory. Analysis of National Center for Atmospheric Research (NCAR) Integrated Sounding System (ISS) data shows that a highly pronounced curvature in the profile of bore-relative winds, related to the existence of a very strong low-level jet, effectively trapped the upward leakage of solitary wave energy below 3 km. This finding explains the trapped lee wave-type structures seen in the DIAL, GLOW, and S-Pol data. C1 [Koch, Steven E.] NOAA, ESRL, R GSD, Global Syst Div, Boulder, CO 80305 USA. [Flamant, Cyrille] UVSQ, UPMC, CNRS, Serv Aeron,Inst Pierre Simon Laplace, Paris, France. [Wilson, James W.] Natl Ctr Atmospher Res, Boulder, CO 80307 USA. [Gentry, Bruce M.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Koch, SE (reprint author), NOAA, ESRL, R GSD, Global Syst Div, 325 Broadway, Boulder, CO 80305 USA. EM steven.koch@noaa.gov RI Jamison, Brian/M-1109-2015 NR 31 TC 9 Z9 9 U1 2 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 AUG PY 2008 VL 25 IS 8 BP 1267 EP 1287 DI 10.1175/2007JTECHA951.1 PG 21 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 347PO UT WOS:000259153700003 ER PT J AU Leblanc, T McDermid, IS Aspey, RA AF Leblanc, Thierry McDermid, I. Stuart Aspey, Robin A. TI First-year operation of a new water vapor Raman lidar at the JPL table mountain facility, California SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article; Proceedings Paper CT 7th International Symposium on Tropospheric Profiling CY JUN, 2006 CL Boulder, CO ID BACKSCATTER; MIDDLE AB A new water vapor Raman lidar was recently built at the Table Mountain Facility (TMF) of the Jet Propulsion Laboratory (JPL) in California and more than a year of routine 2-h-long nighttime measurements 4-5 times per week have been completed. The lidar was designed to reach accuracies better than 5% anywhere up to 12-km altitude, and with the capability to measure water vapor mixing ratios as low as 1 to 10 ppmv near the tropopause and in the lower stratosphere. The current system is not yet fully optimized but has already shown promising results as water vapor profiles have been retrieved up to 18-km altitude. Comparisons with Vaisala RS92K radiosondes exhibit very good agreement up to at least 10 km. They also revealed a wet bias in the lidar profiles ( or a dry bias in the radiosonde profiles), increasing with altitude and becoming significant near 10 km and large when approaching the tropopause. This bias cannot be explained solely by well-known too-dry measurements of the RS92K in the upper troposphere and therefore must partly originate in the lidar measurements. Excess signal due to residual fluorescence in the lidar receiver components is among the most likely candidates and is subject to ongoing investigation. C1 [Leblanc, Thierry; McDermid, I. Stuart; Aspey, Robin A.] 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 11 TC 18 Z9 18 U1 0 U2 0 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 AUG PY 2008 VL 25 IS 8 BP 1454 EP 1462 DI 10.1175/2007JTECHA978.1 PG 9 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 347PO UT WOS:000259153700016 ER PT J AU Yizengaw, E Moldwin, MB Galvan, D Iijima, BA Komjathy, A Mannucci, AJ AF Yizengaw, E. Moldwin, M. B. Galvan, D. Iijima, B. A. Komjathy, A. Mannucci, A. J. TI Global plasmaspheric TEC and its relative contribution to GPS TEC SO JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS LA English DT Article DE ionosphere; plasmasphere; top-side ionosphere; GPS TEC ID TOTAL ELECTRON-CONTENT; SEVERE MAGNETIC STORM; IONOSPHERIC SIGNATURES; SOUTHERN-HEMISPHERE; PROTONOSPHERE; REGION AB The plasmaspheric electron content is directly estimated from the global positioning system (GPS) data onboard JASON-1 Satellite for the first time. Similarly, the ground-based GPS total electron content (TEC) is estimated using about 1000GPS receivers distributed around the globe. The relative contribution of the plasmaspheric electron content to the ground-based GPS TEC is then estimated globally using these two independent simultaneous measurements; namely ground-based GPS TEC and JASON-1 GPS TEC. Results presented here include data from 3 months of different solar cycle conditions (October 2003, May 2005, and December 2006). The global comparison between the two independent measurements was performed by dividing the data into three different regions; equatorial, mid- and high-latitude regions. This division is essential as the GPS raypaths traverse different distances through the plasmasphere at different latitudes. The raypath length through the plasmasphere decreases as latitude increases. The relative contribution of the plasmaspheric electron content exhibits a diurnal variation that depends on latitude with minimum contribution (similar to 10%) during daytime and maximum (up to 60%) at night. The contribution is also maximum at the equatorial region where the GPS raypath traverses a long distance through the plasmasphere compared to its length in mid- and high-latitude regions. Finally, the solar cycle variation of plasmaspheric contribution is also reported globally. (c) 2008 Elsevier Ltd. All rights reserved. C1 [Yizengaw, E.; Moldwin, M. B.; Galvan, D.] Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA 90095 USA. [Iijima, B. A.; Komjathy, A.; Mannucci, A. J.] CALTECH, Jet Prop Lab, Pasadena, CA USA. RP Yizengaw, E (reprint author), Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA 90095 USA. EM ekassie@igpp.ucla.edu RI Moldwin, Mark/F-8785-2011; Yizengaw, Endawoke/I-3471-2015 OI Moldwin, Mark/0000-0003-0954-1770; Yizengaw, Endawoke/0000-0001-5772-3355 FU NSF [ATM-0524711, ATM-0348398]; NASA [NNX07AM22G]; California Institute of Technology; National Aeronautics and Space Administration (NASA) FX This research work has been financially supported by NSF grants ATM-0524711 and ATM-0348398, and NASA grant NNX07AM22G. The authors thank the IGS for providing GPS data provision. Portions of this research were carried out at the jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration (NASA). NR 23 TC 46 Z9 46 U1 2 U2 6 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 AUG PY 2008 VL 70 IS 11-12 BP 1541 EP 1548 DI 10.1016/j.jastp.2008.04.022 PG 8 WC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences SC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences GA 342PZ UT WOS:000258797300015 ER PT J AU Yang, S Smith, EA AF Yang, Song Smith, Eric A. TI Convective-stratiform precipitation variability at seasonal scale from 8 yr of TRMM observations: Implications for multiple modes of diurnal variability SO JOURNAL OF CLIMATE LA English DT Article; Proceedings Paper CT 27th Conference on Hurricanes and Tropical Meteorology CY APR 24-28, 2006 CL Monterey, CA SP Amer Meteorol Soc ID MEASURING MISSION TRMM; LATENT HEATING DISTRIBUTIONS; PASSIVE MICROWAVE RADIOMETRY; TROPICAL OCEANIC CONVECTION; RAIN-PROFILING ALGORITHM; MIDLATITUDE SQUALL LINE; TOGA COARE; MARINE STRATOCUMULUS; GLOBAL PRECIPITATION; CUMULUS CONVECTION AB This study investigates the variability of convective and stratiform rainfall from 8 yr (1998-2005) of Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR) and TRMM Microwave Imager (TMI) measurements, focusing on seasonal diurnal variability. The main scientific goals are 1) to understand the climatological variability of these two dominant forms of precipitation across the four cardinal seasons and over continents and oceans separately and 2) to understand how differences in convective and stratiform rainfall variations ultimately determine how the diurnal variability of the total rainfall is modulated into multiple modes. There are distinct day-night differences for both convective and stratiform rainfall. Oceanic (continental) convective rainfall is up to 25% (50%) greater during nighttime (daytime) than daytime (nighttime). The seasonal variability of convective rainfall's day-night difference is relatively small, while stratiform rainfall exhibits very apparent day-night variations with seasonal variability. There are consistent late evening diurnal peaks without obvious seasonal variations over ocean for convective, stratiform, and total rainfall. Over continents, convective and total rainfall exhibit consistent dominant afternoon peaks with little seasonal variations-but with late evening secondary peaks exhibiting seasonal variations. Stratiform rainfall over continents exhibits a consistent strong late evening peak and a weak afternoon peak, with the afternoon mode undergoing seasonal variability. Thus, the diurnal characteristics of stratiform rainfall appear to control the afternoon secondary maximum of oceanic rainfall and the late evening secondary peak of continental rainfall. Even at the seasonal-regional scale spatially or the interannual global scale temporally, the secondary mode can become very pronounced, but only on an intermittent basis. Overall, the results presented here demonstrate the importance of partitioning the total rainfall into convective and stratiform components and suggest that diurnal modes largely arise from distinct diurnal stratiform variations modulating convective variations. C1 [Yang, Song; Smith, Eric A.] NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. [Yang, Song] George Mason Univ, Coll Sci, Ctr Earth Observing & Space Res, Fairfax, VA 22030 USA. RP Yang, S (reprint author), NASA, Goddard Space Flight Ctr, Atmospheres Lab, Code 613-1, Greenbelt, MD 20771 USA. EM ysong@agnes.gsfc.nasa.gov NR 82 TC 48 Z9 58 U1 3 U2 16 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 AUG PY 2008 VL 21 IS 16 BP 4087 EP 4114 DI 10.1175/2008JCLI2096.1 PG 28 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 339IV UT WOS:000258572200010 ER PT J AU Yang, S Kuo, KS Smith, EA AF Yang, Song Kuo, Kwo-Sen Smith, Eric A. TI Persistent nature of secondary diurnal modes of precipitation over oceanic and continental regimes SO JOURNAL OF CLIMATE LA English DT Article; Proceedings Paper CT 27th Conference on Hurricanes and Tropical Meteorology CY APR 24-28, 2006 CL Monterey, CA SP Amer Meteorol Soc ID TROPICAL PACIFIC-OCEAN; SURFACE-ENERGY BUDGET; CUMULUS CONVECTION; CYCLE; RAINFALL; VARIABILITY; MECHANISMS; RADIATION; ATLANTIC; BEHAVIOR AB This investigation seeks a better understanding of the assorted mechanisms controlling the global distribution of diurnal precipitation variability based on the use of the Tropical Rainfall Measuring Mission (TRMM) microwave radiometer and radar data. The horizontal distributions of precipitation's diurnal cycle are derived from 8 yr of TRMM Microwave Imager (TMI) and Precipitation Radar (PR) measurements involving three TRMM standard rain retrieval algorithms; the resultant distributions are analyzed at various spatiotemporal scales. The results reveal both the prominent and expected late-evening (LE) to early-morning (EM) precipitation maxima over oceans and the counterpart prominent and expected mid-to late-afternoon (MLA) maxima over continents. Moreover, and not generally recognized, the results reveal a widespread distribution of secondary maxima, which generally mirror their counterpart regime's behavior, occurring over both oceans and continents. That is, many ocean regions exhibit clear-cut secondary MLA precipitation maxima, while many continental regions exhibit just as evident secondary LE-EM maxima. This investigation is the first comprehensive study of these globally prevalent secondary maxima and their widespread nature, a type of study only made possible when the analysis procedure is applied to a high-quality global-scale precipitation dataset. The characteristics of the secondary maxima are mapped and described on global grids using an innovative clock-face format, while a current study that is to be published at a later date provides physically based explanations of the seasonal regional distributions of the secondary maxima. In addition to a primary "explicit" maxima identification scheme, a secondary "Fourier decomposition" maxima identification scheme is used as a cross-check to examine the amplitude and phase properties of the multimodal maxima. Accordingly, the advantages and ambiguities resulting from the use of a Fourier harmonic analysis are investigated. C1 [Yang, Song] George Mason Univ, Coll Sci, Ctr Earth Observing & Space Res, Fairfax, VA 22030 USA. [Kuo, Kwo-Sen] Caelum Res Corp, GEST, Greenbelt, MD USA. [Yang, Song; Kuo, Kwo-Sen; Smith, Eric A.] NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. RP Yang, S (reprint author), NASA, Goddard Space Flight Ctr, Lab Atmospheres Code 613 1, Greenbelt, MD 20771 USA. EM ysong@agnes.gsfc.nasa.gov NR 36 TC 26 Z9 29 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 AUG PY 2008 VL 21 IS 16 BP 4115 EP 4131 DI 10.1175/2008JCLI2140.1 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 339IV UT WOS:000258572200011 ER PT J AU Reppond, K Rugolo, L de Oliveira, ACM AF Reppond, Kermit Rugolo, Louis de Oliveira, Alexandra C. M. TI Change in biochemical composition during development of snow crab, Chionoecetes opilio, embryos SO JOURNAL OF CRUSTACEAN BIOLOGY LA English DT Article DE Chionoecetes opilio; embryonic development; fatty acid; lipid; snow crab ID FATTY-ACID-COMPOSITION; LARVAL DEVELOPMENT; MACROBRACHIUM-ROSENBERGII; PALAEMON-SERRATUS; LIPID-COMPOSITION; ENRICHED ARTEMIA; DEVELOPING EGGS; DECAPODA; BROODSTOCK; PERFORMANCE AB Adult oveigerous female snow crab, Chionoecetes opilio, were obtained approximately bimonthly from the eastern Bering Sea for embryonic sampling and biometric information. Biochemical analysis of embryo samples included determination of moisture, ash, total lipid, protein content, fatty acid profile, and lipid profile. Moisture increased as the embryos matured. Protein content remained unchanged, ash content increased, and lipid content decreased on a dry weight basis coincident with embryonic development indicating that lipids were the main energy source of developing embryos. The utilization of saturated, monounsaturated, and polyunsaturated fatty acid categories during development was similar but individual fatty acids within each category varied considerably. Over 75% of the C14:0, C18:4(n-3), and C20:1(n-11) fatty acids were consumed during the embryonic development from nauplius to pre-hatch while C22:5(n-3), C20:5(n-3), and C18:1(n-9)cis fatty acids were utilized at 49%, 57%, and 48% respectively. Docosahexaenoic acid, DHA, C22:6(n-3), was among the least utilized fatty acid at 36%. Forward stepwise general discriminant analysis of fatty acid profiles indicated that determination of fatty acid profiles could be used to distinguish between embryos at the nauplius stage and the prehatching stage of development but not among embryos at intermediate stages. Triacylglycerides provided the energy source during development. This research highlights the potential nutrient requirements critical to early life-history development of Bering Sea snow crabs. C1 [Reppond, Kermit] Natl Marine Fisheries Serv, Manchester, WA 98353 USA. [Rugolo, Louis] Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Kodiak Fishery Res Lab, Kodiak, AK 99615 USA. Univ Alaska, Fishery Ind Technol Ctr, Kodiak, AK 99615 USA. RP Reppond, K (reprint author), Natl Marine Fisheries Serv, POB 130, Manchester, WA 98353 USA. EM kermit.d.reppond@noaa.gov; lou.rugolo@noaa.gov; ffamo@uaf.edu NR 48 TC 4 Z9 4 U1 0 U2 2 PU CRUSTACEAN SOC PI SAN ANTONIO PA 840 EAST MULBERRY, SAN ANTONIO, TX 78212 USA SN 0278-0372 J9 J CRUSTACEAN BIOL JI J. Crustac. Biol. PD AUG PY 2008 VL 28 IS 3 BP 519 EP 527 DI 10.1651/07-2862R1.1 PG 9 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA 329UQ UT WOS:000257896500012 ER PT J AU Barry, KP Condrey, RE Driggers, WB Jones, CM AF Barry, K. P. Condrey, R. E. Driggers, W. B., III Jones, C. M. TI Feeding ecology and growth of neonate and juvenile blacktip sharks Carcharhinus limbatus in the Timbalier-Terrebone Bay complex, LA, USA SO JOURNAL OF FISH BIOLOGY LA English DT Article DE diel feeding patterns; diet; menhaden; nursery area ID GULF-OF-MEXICO; LIFE-HISTORY; SPHYRNA-LEWINI; UNITED-STATES; NURSERY; AGE; FISHES AB Stomach contents and vertebrae from neonate and juvenile blacktip sharks Carcharhinus limbatus (n = 334) were examined to describe their diet, feeding patterns and growth within the Timbalier-Terrebone Bay complex, LA, U.S.A. In the study area, both neonate and juvenile C. limbatus feed primarily on gulf menhaden Brevoortia patronus. However, based on the index of relative importance (I(RI)), gulf menhaden constituted a larger portion of the diet of neonates (84.05 %I(RI)) than for juveniles (47.91 %I(RI)). An increase in the index of relative fullness between the afternoon and dusk time intervals and a large decrease in the percentage of empty stomachs between the night and early morning time intervals suggested that these fish exhibited a diel feeding pattern with crepuscular periods being the times of highest feeding activity. A higher percentage of empty stomachs (neonates 68% and juveniles 39%) and a significantly lower growth rate (age 0+ year C. limbatus, 0.62 mm day(-1); age 1+ year fish, 0.89 mm day(-1)) could indicate that neonate C. limbatus are less efficient predators than older conspecifics. Journal compilation (C) 2008 The Fisheries Society of the British Isles. C1 [Driggers, W. B., III; Jones, C. M.] SE Fisheries Sci Ctr, Natl Marine Fisheries Serv, Mississippi Labs, Pascagoula, MS 39567 USA. [Barry, K. P.; Condrey, R. E.] Louisiana State Univ, Dept Oceanog, Baton Rouge, LA 70803 USA. RP Barry, KP (reprint author), SE Fisheries Sci Ctr, Natl Marine Fisheries Serv, Mississippi Labs, 3209 Freder St, Pascagoula, MS 39567 USA. EM kevin.barry@noaa.gov NR 32 TC 14 Z9 14 U1 2 U2 13 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0022-1112 J9 J FISH BIOL JI J. Fish Biol. PD AUG PY 2008 VL 73 IS 3 BP 650 EP 662 DI 10.1111/j.1095-8649.2008.01963.x PG 13 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 333RK UT WOS:000258169800013 ER PT J AU Su, FG Hong, Y Lettenmaier, DP AF Su, Fengge Hong, Yang Lettenmaier, Dennis P. TI Evaluation of TRMM Multisatellite Precipitation Analysis (TMPA) and its utility in hydrologic prediction in the La Plata Basin SO JOURNAL OF HYDROMETEOROLOGY LA English DT Article ID MEASURING MISSION TRMM; TROPICAL RAINFALL; UNITED-STATES; ROUTING MODEL; SOUTH-AMERICA; VIC-2L MODEL; SATELLITE; RIVER; PROJECT; RESOLUTION AB Satellite-based precipitation estimates with high spatial and temporal resolution and large areal coverage provide a potential alternative source of forcing data for hydrological models in regions where conventional in situ precipitation measurements are not readily available. The La Plata basin in South America provides a good example of a case where the use of satellite-derived precipitation could be beneficial. This study evaluates basinwide precipitation estimates from 9 yr (1998-2006) of Tropical Rainfall Measuring Mission (TRMM) Multisatellite Precipitation Analysis (TMPA; 3B42 V. 6) through comparison with available gauged data and the Variable Infiltration Capacity (VIC) semidistributed hydrology model applied to the La Plata basin. In general, the TMPA estimates agreed well with the gridded gauge data at monthly time scales, most likely because of the monthly adjustment to gauges performed in TMPA. The agreement between TMPA and gauge precipitation estimates was reduced at daily time scales, particularly for high rain rates. The TMPA-driven hydrologic model simulations were able to capture the daily flooding events and to represent low flows, although peak flows tended to be biased upward. There was a good agreement between TMPA-driven simulated flows in terms of their reproduction of seasonal and interannual stream-flow variability. This analysis shows that TMPA has potential for hydrologic forecasting in data-sparse regions. C1 [Su, Fengge; Lettenmaier, Dennis P.] Univ Washington, Dept Civil & Environm Engn, Seattle, WA 98195 USA. [Hong, Yang] Goddard Earth Sci Technol Ctr, Greenbelt, MD USA. [Hong, Yang] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Lettenmaier, DP (reprint author), Univ Washington, Dept Civil & Environm Engn, Seattle, WA 98195 USA. EM dennisl@u.washington.edu RI Hong, Yang/D-5132-2009; lettenmaier, dennis/F-8780-2011 OI Hong, Yang/0000-0001-8720-242X; lettenmaier, dennis/0000-0003-3317-1327 NR 54 TC 198 Z9 223 U1 10 U2 56 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 AUG PY 2008 VL 9 IS 4 BP 622 EP 640 DI 10.1175/2007JHM944.1 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 337QQ UT WOS:000258451000002 ER PT J AU Mahanama, SPP Koster, RD Reichle, RH Suarez, MJ AF Mahanama, Sarith P. P. Koster, Randal D. Reichle, Rolf H. Suarez, Max J. TI Impact of subsurface temperature variability on surface air temperature variability: An AGCM study SO JOURNAL OF HYDROMETEOROLOGY LA English DT Article ID GENERAL-CIRCULATION MODELS; LAND-ATMOSPHERE SYSTEM; SOIL WETNESS; MEMORY; PREDICTABILITY; PERSISTENCE; PREDICTION; VEGETATION; LAYER AB Anomalous atmospheric conditions can lead to surface temperature anomalies, which in turn can lead to temperature anomalies in the subsurface soil. The subsurface soil temperature (and the associated ground heat content) has significant memory-the dissipation of a temperature anomaly may take weeks to months-and thus subsurface soil temperature may contribute to the low-frequency variability of energy and water variables elsewhere in the system. The memory may even provide some skill to subseasonal and seasonal forecasts. This study uses three long-term AGCM experiments to isolate the contribution of subsurface soil temperature variability to variability elsewhere in the climate system. The first experiment consists of a standard ensemble of Atmospheric Model Intercomparison Project (AMIP)-type simulations in which the subsurface soil temperature variable is allowed to interact with the rest of the system. In the second experiment, the coupling of the subsurface soil temperature to the rest of the climate system is disabled; that is, at each grid cell, the local climatological seasonal cycle of subsurface soil temperature (as determined from the first experiment) is prescribed. Finally, a climatological seasonal cycle of sea surface temperature (SST) is prescribed in the third experiment. Together, the three experiments allow the isolation of the contributions of variable SSTs, interactive subsurface soil temperature, and chaotic atmospheric dynamics to meteorological variability. The results show that allowing an interactive subsurface soil temperature does, indeed, significantly increase surface air temperature variability and memory in most regions. In many regions, however, the impact is negligible, particularly during boreal summer. C1 [Mahanama, Sarith P. P.; Koster, Randal D.; Reichle, Rolf H.; Suarez, Max J.] NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Greenbelt, MD 20771 USA. [Mahanama, Sarith P. P.; Reichle, Rolf H.; Suarez, Max J.] Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21228 USA. RP Mahanama, SPP (reprint author), NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Code 610-1, Greenbelt, MD 20771 USA. EM sarith@gmao.gsfc.nasa.gov RI Reichle, Rolf/E-1419-2012; Koster, Randal/F-5881-2012 OI Koster, Randal/0000-0001-6418-6383 NR 27 TC 7 Z9 8 U1 0 U2 4 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 AUG PY 2008 VL 9 IS 4 BP 804 EP 815 DI 10.1175/2008JHM949.1 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 337QQ UT WOS:000258451000013 ER PT J AU Wang, XY Wang, W Huang, Y Nguyen, N Krishnakumar, K AF Wang, Xiaoyu Wang, Wen Huang, Yong Nguyen, Nhan Krishnakumar, Kalmanje TI Design of neural network-based estimator for tool wear modeling in hard turning SO JOURNAL OF INTELLIGENT MANUFACTURING LA English DT Article DE tool wear; hard turning; neural network; extended Kalman filter; connectivity optimization ID FLANK WEAR; CRATER WEAR; ONLINE; BACKPROPAGATION; SYSTEM; OPTIMIZATION; INTEGRATION; PREDICTION; ALGORITHM; ERROR AB Hard turning with cubic boron nitride (CBN) tools has been proven to be more effective and efficient than traditional grinding operations in machining hardened steels. However, rapid tool wear is still one of the major hurdles affecting the wide implementation of hard turning in industry. Better prediction of the CBN tool wear progression helps to optimize cutting conditions and/or tool geometry to reduce tool wear, which further helps to make hard turning a viable technology. The objective of this study is to design a novel but simple neural network-based generalized optimal estimator for CBN tool wear prediction in hard turning. The proposed estimator is based on a fully forward connected neural network with cutting conditions and machining time as the inputs and tool flank wear as the output. Extended Kalman filter algorithm is utilized as the network training algorithm to speed up the learning convergence. Network neuron connection is optimized using a destructive optimization algorithm. Besides performance comparisons with the CBN tool wear measurements in hard turning, the proposed tool wear estimator is also evaluated against a multilayer perceptron neural network modeling approach and/or an analytical modeling approach, and it has been proven to be faster, more accurate, and more robust. Although this neural network-based estimator is designed for CBN tool wear modeling in this study, it is expected to be applicable to other tool wear modeling applications. C1 [Wang, Xiaoyu; Huang, Yong] Clemson Univ, Dept Mech Engn, Clemson, SC 29634 USA. [Wang, Wen] Zhejiang Univ, Coll Mech & Energy Engn, Hangzhou 310027, Peoples R China. [Nguyen, Nhan; Krishnakumar, Kalmanje] NASA, Ames Res Ctr, Intelligent Syst Div, Moffett Field, CA 94035 USA. RP Huang, Y (reprint author), Clemson Univ, Dept Mech Engn, Clemson, SC 29634 USA. EM yongh@clemson.edu NR 57 TC 33 Z9 34 U1 1 U2 11 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0956-5515 EI 1572-8145 J9 J INTELL MANUF JI J. Intell. Manuf. PD AUG PY 2008 VL 19 IS 4 BP 383 EP 396 DI 10.1007/s10845-008-0090-8 PG 14 WC Computer Science, Artificial Intelligence; Engineering, Manufacturing SC Computer Science; Engineering GA 320LX UT WOS:000257237700002 ER PT J AU deGroh, HC Ellis, DL Loewenthal, WS AF deGroh, Henry C., III Ellis, David L. Loewenthal, William S. TI Comparison of GRCop-84 to other Cu alloys with high thermal conductivities SO JOURNAL OF MATERIALS ENGINEERING AND PERFORMANCE LA English DT Article DE AMZIRC; compression; copper; creep; Cu-Cr; Cu-Cr-Zr; GlidCop Al-15; GRCop-84; mechanical properties; NARloy-Z; tension ID CR AB The mechanical properties of six highly conductive copper alloys, GRCop-84, AMZIRC, GlidCop Al-15, Cu-1Cr-0.1Zr, Cu-0.9Cr, and NARloy-Z were compared. Tests were done on as-received hard drawn material, and after a heat treatment designed to simulate a brazing operation at 935 degrees C. In the as-received condition AMZIRC, GlidCop Al-15, Cu-1Cr-0.1Zr, and Cu-0.9Cr had excellent strengths at temperatures below 500 degrees C. However, the brazing heat treatment substantially decreased the mechanical properties of AMZIRC, Cu-1Cr-0.1Zr, Cu-0.9Cr, and NARloy-Z. The properties of GlidCop Al-15 and GRCop-84 were not significantly affected by the heat treatment. Thus there appear to be advantages to GRCop-84 over AMZIRC, Cu-1Cr-0.1Zr, Cu-0.9Cr, and NARloy-Z if use or processing temperatures greater than 500 degrees C are expected. Ductility was the lowest in GlidCop Al-15 and Cu-0.9Cr; reduction in area was particularly low in GlidCop Al-15 above 500 degrees C, and as-received Cu-0.9Cr was brittle between 500 and 650 degrees C. Tensile creep tests were done at 500 and 650 degrees C; the creep properties of GRCop-84 were superior to those of brazed AMZIRC, Cu-1Cr-0.1Zr, Cu-0.9Cr, and NARloy-Z. In the brazed condition, GRCop-84 was superior to the other alloys due to its greater strength and creep resistance (compared to AMZIRC, Cu-1Cr-0.1Zr, Cu-0.9Cr, and NARloy-Z) and ductility (compared to GlidCop Al-15). C1 [deGroh, Henry C., III; Ellis, David L.] NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. [Loewenthal, William S.] Ohio Aerosp Inst, Cleveland, OH 44135 USA. RP deGroh, HC (reprint author), NASA, Glenn Res Ctr, 21000 Brookpk Rd, Cleveland, OH 44135 USA. EM henry.c.degroh@nasa.gov NR 29 TC 7 Z9 7 U1 1 U2 7 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1059-9495 J9 J MATER ENG PERFORM JI J. Mater. Eng. Perform. PD AUG PY 2008 VL 17 IS 4 BP 594 EP 606 DI 10.1007/s11665-007-9175-3 PG 13 WC Materials Science, Multidisciplinary SC Materials Science GA 325IO UT WOS:000257582800018 ER PT J AU Liu, WT Xie, XS AF Liu, W. Timothy Xie, Xiaosu TI Ocean-atmosphere momentum coupling in the Kuroshio Extension observed from space SO JOURNAL OF OCEANOGRAPHY LA English DT Article; Proceedings Paper CT 14th Pacific Marginal Seas/Japan and East China Sea Study Workshop (PAMS/JECSS) CY MAY 23-26, 2007 CL Hiroshima Univ, Higashi Hiroshima, JAPAN HO Hiroshima Univ DE wind-stress; ocean-front; buoyancy; current-shear; scatterometer; ocean-atmosphere-coupling; divergence; vorticity ID SEA-SURFACE TEMPERATURE; SATELLITE MEASUREMENTS; BULK PARAMETERIZATION; WIND STRESS; HEAT; FLUX AB Using a combination of Quick Scatterometer (QuikSCAT), Advanced Microwave Scanning Radiometer-Earth Observing System (AMSR-E), and Lagrangian drifter measurements, we demonstrate that wind data alone are not sufficient to derive ocean surface stress (momentum flux) over mid-latitude ocean fronts, specifically the Kuroshio Extension. There was no continuous and large-scale stress measurement over ocean until the launch of the scatterometers. Stress had been derived from winds through a drag coefficient, and our concept of stress distribution may be largely influenced by our knowledge of wind distribution. QuikSCAT reveals that the variability of stress could be very different from wind. The spatial coherence between the magnitude of stress and sea surface temperature (SST), between the divergence of surface stress and the downwind SST gradient, and between the vorticity of stress and crosswind SST gradient, are the inherent characteristics of stress (turbulence production by buoyancy) that would exist even under a uniform wind field. The coherence between stress vorticity and SST gradient is masked by the rotation of ocean currents over the Kuroshio meanders. Surface stress rotates in the opposite direction to surface currents because stress is the vector difference between wind and current. The results are in agreement with a previous study of the Agulhas Extension and confirm the unique stress measuring capability of the scatterometer. C1 [Liu, W. Timothy; Xie, Xiaosu] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Liu, WT (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM W.Timothy.Liu@jpl.nasa.gov NR 24 TC 10 Z9 10 U1 1 U2 3 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0916-8370 J9 J OCEANOGR JI J. Oceanogr. PD AUG PY 2008 VL 64 IS 4 BP 631 EP 637 DI 10.1007/s10872-008-0053-x PG 7 WC Oceanography SC Oceanography GA 328PE UT WOS:000257809500014 ER PT J AU Moretto, A Formaggio, F Toniolo, C Broxterman, QB Weber, AL Pizzarello, S AF Moretto, Alessandro Formaggio, Fernando Toniolo, Claudio Broxterman, Quirinus B. Weber, Arthur L. Pizzarello, Sandra TI Exogenous delivery and molecular evolution: peptides based on C degrees-methylated alpha-amino acid as asymmetric catalysts in the syntheses of simple sugars SO JOURNAL OF PEPTIDE SCIENCE LA English DT Meeting Abstract C1 [Moretto, Alessandro; Formaggio, Fernando; Toniolo, Claudio] Univ Padua, Dept Chem, Inst Biomol Chem, CNR,Padova Unit, I-35131 Padua, Italy. [Broxterman, Quirinus B.] DSM Pharmaceut Prod, Adv Synthesis Catalysis & Dev, NL-6160 MD Geleen, Netherlands. [Weber, Arthur L.] SETI Inst, Ames Res Ctr, Moffett Field, CA 94035 USA. [Pizzarello, Sandra] Arizona State Univ, Dept Biochem & Chem, Tempe, AZ 85018 USA. NR 0 TC 0 Z9 0 U1 0 U2 2 PU JOHN WILEY & SONS LTD PI CHICHESTER PA THE ATRIUM, SOUTHERN GATE, CHICHESTER PO19 8SQ, W SUSSEX, ENGLAND SN 1075-2617 J9 J PEPT SCI JI J. Pept. Sci. PD AUG PY 2008 VL 14 IS 8 SU S BP 77 EP 78 PG 2 WC Biochemistry & Molecular Biology; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA 345VZ UT WOS:000259026900225 ER PT J AU Zubko, E Shkuratov, Y Mishchenko, M Videen, G AF Zubko, Evgenij Shkuratov, Yuriy Mishchenko, Michael Videen, Gorden TI Light scattering in a finite multi-particle system SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article DE negative polarization branch; coherent backscattering; multiple scattering ID DISCRETE-DIPOLE APPROXIMATION; COHERENT BACKSCATTERING ENHANCEMENT; AGGLOMERATED DEBRIS PARTICLES; RANDOM-MEDIA; NEGATIVE POLARIZATION; COMETARY DUST; SPHERICAL-PARTICLES; AGGREGATE PARTICLES; WEAK-LOCALIZATION; PHASE ANGLES AB We use the discrete dipole approximation (DDA) to perform electromagnetic scattering calculations of particles in a 3D volume. We adjust the spacing between the particles to change the volume densities of the scattering systems from approximately 10% to 100%. For very large volume densities, e.g. > 50%, it is difficult to assign unambiguously whether the system is composed of a single heterogeneous particle or of multiple particles. Our calculations demonstrate optical effects attributable to multiple scattering in systems having volume densities as high as similar to 90%. This suggests that heterogeneities within naturally occurring particle systems can produce multiple-scattering effects. We also see evidence of very deep negative polarization branches (NPBs) (similar to-6%) that may have implications in interpreting polarization phase curves of cometary circumnuclear halos. Published by Elsevier Ltd. C1 [Videen, Gorden] USA, Res Lab, AMSRL CI EM, Adelphi, MD 20783 USA. [Zubko, Evgenij] Hokkaido Univ, Inst Low Temp Sci, Kita Ku, Sapporo, Hokkaido 0600819, Japan. [Zubko, Evgenij; Shkuratov, Yuriy] Kharkov Natl Univ, Astron Inst, UA-61022 Kharkov, Ukraine. [Shkuratov, Yuriy] Natl Acad Sci Ukraine, Inst Radio Astron, UA-61002 Kharkov, Ukraine. [Mishchenko, Michael] NASA, Goddard Inst Space Studies, New York, NY 10025 USA. RP Videen, G (reprint author), USA, Res Lab, AMSRL CI EM, 2800 Powder Mill Rd, Adelphi, MD 20783 USA. EM gvideen@arl.army.mil RI Mishchenko, Michael/D-4426-2012 NR 76 TC 33 Z9 33 U1 0 U2 6 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 AUG-SEP PY 2008 VL 109 IS 12-13 BP 2195 EP 2206 DI 10.1016/j.jqsrt.2008.03.007 PG 12 WC Optics; Spectroscopy SC Optics; Spectroscopy GA 330TT UT WOS:000257966400005 ER PT J AU Baranov, YI Lafferty, WJ Ma, Q Tipping, RH AF Baranov, Yu. I. Lafferty, W. J. Ma, Q. Tipping, R. H. TI Water-vapor continuum absorption in the 800-1250 cm(-1) spectral region at temperatures from 311 to 363 K SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article DE water-vapor absorption spectra; MT_CKD continuum; atmospheric absorption ID COORDINATE REPRESENTATION; INFRARED-SPECTRUM; DENSITY-MATRIX; LINE-SHAPES; MIXTURES; WINDOW; H2O; MU; RADIATION AB About 200 pure water-vapor spectra covering the region from 800 to 3500 cm(-1) were recorded with resolution of 0.1 cm(-1) at temperatures 311, 318, 325,339, 352,and 363 K using a 2 m base White cell coupled to the BOMEM DA3.002 FTIR spectrometer. The water-vapor pressure varied from 28 to 151 mbar (21-113 Torr). Under these conditions, the continuum absorbance is quite measurable with the available path lengths up to 116 m. A program was developed for spectral processing that calculates, fits, and removes ro-vibrational structure from the spectrum. The spectra obtained were used to retrieve averaged and smoothed binary absorption coefficients over the region from 800 to 1250 cm(-1). Our continuum data extrapolated to room temperature are in reasonable agreement with the MT_CKD continuum model. But at higher temperatures the MT_CKD model provides very low values, which are up to 50% less than those experimentally measured. Published by Elsevier Ltd. C1 [Baranov, Yu. I.; Lafferty, W. J.] NIST, Opt Technol Div, Gaithersburg, MD 20899 USA. [Ma, Q.] Columbia Univ, Dept Appl Phys, New York, NY 10027 USA. [Ma, Q.] NASA, Goddard Space Flight Ctr, Inst Space Studies, New York, NY 10025 USA. [Tipping, R. H.] Univ Alabama, Dept Phys & Astron, Tuscaloosa, AL 35487 USA. RP Lafferty, WJ (reprint author), NIST, Opt Technol Div, Gaithersburg, MD 20899 USA. EM Walter.Lafferty@nist.gov NR 36 TC 33 Z9 43 U1 1 U2 5 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 AUG-SEP PY 2008 VL 109 IS 12-13 BP 2291 EP 2302 DI 10.1016/j.jqsrt.2008.03.004 PG 12 WC Optics; Spectroscopy SC Optics; Spectroscopy GA 330TT UT WOS:000257966400012 ER PT J AU Sayir, A AF Sayir, Ali TI Papers Presented at the Second International Workshop on Directionally Solidified Eutectic Ceramics - Preface SO JOURNAL OF THE EUROPEAN CERAMIC SOCIETY LA English DT Editorial Material C1 NASA, Lewis Res Ctr, Cleveland, OH 44135 USA. RP Sayir, A (reprint author), NASA, Lewis Res Ctr, MS 106-1,21000 Brookpk Rd, Cleveland, OH 44135 USA. EM Ali.sayir@lerc.nasa.gov NR 0 TC 0 Z9 0 U1 2 U2 3 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0955-2219 J9 J EUR CERAM SOC JI J. Eur. Ceram. Soc. PD AUG PY 2008 VL 28 IS 12 BP 2299 EP 2299 DI 10.1016/j.jeurceramsoc.2008.01.004 PG 1 WC Materials Science, Ceramics SC Materials Science GA 331MD UT WOS:000258015400001 ER PT J AU Berger, MH Sayir, A AF Berger, Marie-Helene Sayir, Ali TI Directional solidification of Al(2)O(3)-Al(2)TiO(5) system SO JOURNAL OF THE EUROPEAN CERAMIC SOCIETY LA English DT Article; Proceedings Paper CT 2nd International Meeting on Directionally Solidified Eutectic Ceramics Workshop CY NOV, 2006 CL Kyoto, JAPAN DE directional solidification; electron microscopy; Al(2)O(3); Al(2)TiO(5) ID EUTECTIC COMPOSITE; CERAMIC EUTECTICS; OXIDES; BEHAVIOR; TITANATE AB Directional solidification of Al(2)O(3)-Al(2)TiO(5) eutectic system was investigated to design in situ composites that could exhibit optimized properties of strength and toughness. Directional solidification of an alumina rich melt was expected to produce primary Al(2)O(3) dendrites, these would act as load bearing component of the structure, separated by a Al(2)O(3)-Al(2)TiO(5) eutectic matrix and. Additional aim was to utilize the differential expansion coefficient between the two phases to produce microcracks and thus weak interfaces for load deflection. Three different melt compositions were investigated; two off-eutectic compositions, at 11,26 mol% TiO(2), and one eutectic at 43.9 mol% TiO(2). The crystallized phases were different than as one would expect from the published phase diagram. Off-eutectics were composed of Al(2)O(3) dendrites separated by a Al(6)Ti(2)O(13) matrix. Eutectic structure was composed of Al(2)TiO(5) lamellae in an aluminum titanate matrix. This matrix consisted of a superstructure made of 5 cells of Al(6)Ti(2)O(13) for one cell of Al(2)TiO(5) along [001] direction. Al(6)TiO(13) phase decomposed by a eutectoid reaction into Al(2)O(3) and Al(2)TiO5. Eutectoid reaction occurred during post heat treatment at 1400 degrees C and decomposition of Al(6)Ti(2)O(13) was completed after 10 h of annealing at 1500 degrees C. Based on these observations, a modification of the alumina rich part of Al(2)O(3)-TiO(2) phase diagram was proposed. A second intermediate compound, Al(6)TiO(13) is introduced as a high temperature phase. Two invariant points, a peritectic (L + Al(2)O(3) -> Al(6)Ti(2)O(13)) and a eutectic (L -> Al(6)Ti(2)O(13) + Al(2)TiO(5)) are also added between Al(6)Ti(2)O(13) and Al(2)TiO(5). (C) 2008 Elsevier Ltd. All rights reserved. C1 [Sayir, Ali] NASA, Glenn Res Ctr, CWRU, Cleveland, OH 44135 USA. [Berger, Marie-Helene] CNRS, Ctr Mat, UMR 7633, F-91003 Evry, France. RP Sayir, A (reprint author), NASA, Glenn Res Ctr, CWRU, MS 106,21000 Brookpk Rd, Cleveland, OH 44135 USA. EM ali.sayir-l@nasa.gov RI Berger, Marie-Helene/B-9785-2013 NR 21 TC 14 Z9 14 U1 0 U2 5 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0955-2219 J9 J EUR CERAM SOC JI J. Eur. Ceram. Soc. PD AUG PY 2008 VL 28 IS 12 BP 2411 EP 2419 DI 10.1016/j.jeurceramsoc.2008.03.005 PG 9 WC Materials Science, Ceramics SC Materials Science GA 331MD UT WOS:000258015400015 ER PT J AU Dynys, FW Berger, MH Sayir, A AF Dynys, F. W. Berger, M. H. Sayir, A. TI Laser processed protonic ceramics SO JOURNAL OF THE EUROPEAN CERAMIC SOCIETY LA English DT Article; Proceedings Paper CT 2nd International Meeting onDirectionally Solidfied Eutectic Ceramics Workshop CY NOV, 2006 CL Kyoto, JAPAN DE laser; protonic; ceramics; films; directional solidification ID COMPLEX PEROVSKITES; BARIUM CERATE; THIN-FILMS; CONDUCTIVITY; DEPOSITION; CONDUCTORS AB High temperature protonic conductors of SrCe0.9Y0.1O3-delta, Sr3Ca1+xNb2-xO9-delta and BaCe0.85Y0.15O3-delta were fabricated by laser processing. Laser float zone method and pulse laser deposition were used to fabricate dense high temperature protonic ceramic rods and films. Melt growth processing by laser float zone produced textured microstructures with cellular characteristics. Directional solidified SrCe0.9Y0.1O3-delta contained an aluminium rich inter-granular phase, whereas Sr3Ca1+xNb2-xO9-delta exhibits a cellular microstructure with a decreasing Ca/Nb ratio from the cell center to the cell boundary. A low Ca/Nb ratio is detrimental to proton transport. Nano-domains caused by oxygen cage tilting were observed in both compositions. Sr3Ca1+xNb2-xO9-delta also exhibits stoichiometric domains with an ordered distribution of Nb5+ and Ca2+ cations. These domains were surrounded by non-stoichiometric domains containing a random cation distribution, which preserves the global stoichiometry and charge neutrality. Electrical impedance spectroscopy revealed similar protonic transport to published data for sintered compositions. Crystalline BaCe0.9Y0.1O3-delta films were fabricated on porous substrates at deposition temperatures ranging from 400 to 950 degrees C. Crystalline films 1-10 mu m thick were deposited by excimer laser on porous Al2O3 and BaZrO3 substrates. Single-phase BaCe0.85Y0.15O3-delta films with a columnar growth morphology are observed with preferred crystal growth along the [100] or [001] direction. The film electrical conductivity was measured perpendicular to the film growth direction. Impedance measurements show the importance of matching crystal symmetry between substrate and film. High protonic conducting films were achieved by deposition on BaZrO3. Published by Elsevier Ltd. C1 [Dynys, F. W.; Sayir, A.] NASA, GRC, CWRU, Cleveland, OH 44135 USA. [Berger, M. H.] Ecole Mines Paris, F-91003 Evry, France. RP Dynys, FW (reprint author), NASA, GRC, CWRU, 21000 Brookpk Rd, Cleveland, OH 44135 USA. EM Frederick.W.Dynys@nasa.gov RI Berger, Marie-Helene/B-9785-2013 NR 23 TC 5 Z9 5 U1 1 U2 6 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0955-2219 J9 J EUR CERAM SOC JI J. Eur. Ceram. Soc. PD AUG PY 2008 VL 28 IS 12 BP 2433 EP 2440 DI 10.1016/j.jeurceramsoc.2008.03.038 PG 8 WC Materials Science, Ceramics SC Materials Science GA 331MD UT WOS:000258015400017 ER PT J AU Karner, JM Papike, JJ Sutton, SR Shearer, CK Burger, P Mckay, G Le, L AF Karner, J. M. Papike, J. J. Sutton, S. R. Shearer, C. K. Burger, P. McKay, G. Le, L. TI Valence state partitioning of V between pyroxene-melt: Effects of pyroxene and melt composition, and direct determination of V valence states by XANES. Application to Martian basalt QUE 94201 composition SO METEORITICS & PLANETARY SCIENCE LA English DT Article ID COMPARATIVE PLANETARY MINERALOGY; MANTLE SOURCE REGIONS; OXYGEN FUGACITY; OXIDATION-STATE; SILICATE MELT; VANADIUM; CLINOPYROXENE; ELEMENT; SPINEL; CR AB Experiments on a Martian basalt composition show that D(V) augite/melt is greater than D(V) pigeonite/melt in samples equilibrated under the same fO(2) conditions. This increase is due to the increased availability of elements for coupled substitution with the V(3+) or V(4+) ions, namely Al and Na. For this bulk composition, both Al and Na are higher in concentration in augite compared with pigeonite; therefore more V can enter augite than pigeonite. Direct valence state determination by XANES shows that the V(3+) and V(4+) are the main V species in the melt at fO(2) conditions of IW-I to IW+3.5. whereas pyroxene grains at IW-1, IW, and IW+1 contain mostly V(3+). This confirms the idea that V(3+) is more compatible in pyroxene than V(4+). The XANES data also indicates that a small percentage of V(2+) may exist in melt and pyroxene at IW-1. The similar valence of V in glass and pyroxene at IW-1 Suggests that V(2+) and V(3+) may have similar compatibilities in pyroxene. C1 [Karner, J. M.; Papike, J. J.; Shearer, C. K.; Burger, P.] Univ New Mexico, Inst Meteorit, Dept Earth & Planetary Sci, Albuquerque, NM 87131 USA. [Sutton, S. R.] Univ Chicago, Dept Geophys Sci, Chicago, IL 60637 USA. [Sutton, S. R.] Univ Chicago, Consortium Adv Radiat Sources, Chicago, IL 60637 USA. [McKay, G.] NASA JSC, Houston, TX 77058 USA. [Le, L.] JE23, ESC Grp, Houston, TX 77058 USA. RP Karner, JM (reprint author), Univ New Mexico, Inst Meteorit, Dept Earth & Planetary Sci, Albuquerque, NM 87131 USA. EM jkarner@unm.edu FU NSF-Earth Sciences [EAR-0622171]; DOE-Geosciences [DE-FG02-94ER 14466]; U.S. DOE, Office of Science, Office of Basic Energy Sciences [DE-AC02-06CH11357] FX NASA Cosmochemistry Grants to J. J. P. and G. M. support this research and are gratefully acknowledged. GeoSoilEnviroCARS is supported by the NSF-Earth Sciences (EAR-0622171) and DOE-Geosciences (DE-FG02-94ER 14466). Use of the APS Was supported by the U.S. DOE, Office of Science, Office of Basic Energy Sciences, Under contract no. DE-AC02-06CH11357. This manuscript greatly benefited from the reviews of C. T. Lee and all anonymous reviewer. We also thank Steve Mackwell and the Lunar and Planetary Institute for supporting the first author as a visiting scientist while performing the experimental work. NR 34 TC 7 Z9 7 U1 0 U2 7 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 1086-9379 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD AUG PY 2008 VL 43 IS 8 BP 1275 EP 1285 PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 381OI UT WOS:000261545400002 ER PT J AU Narum, SR Banks, M Beacham, TD Bellinger, MR Campbell, MR Dekoning, J Elz, A Guthrie, CM Kozfkay, C Miller, KM Moran, P Phillips, R Seeb, LW Smith, CT Warheit, K Young, SF Garza, JC AF Narum, S. R. Banks, M. Beacham, T. D. Bellinger, M. R. Campbell, M. R. Dekoning, J. Elz, A. Guthrie, C. M. Kozfkay, C. Miller, K. M. Moran, P. Phillips, R. Seeb, L. W. Smith, C. T. Warheit, K. Young, S. F. Garza, J. C. TI Differentiating salmon populations at broad and fine geographical scales with microsatellites and single nucleotide polymorphisms SO MOLECULAR ECOLOGY LA English DT Article DE assignment tests; Chinook salmon; differentiation; genetic markers; microsatellites; SNPs ID CROSS-SPECIES AMPLIFICATION; CHINOOK SALMON; ONCORHYNCHUS-TSHAWYTSCHA; ATLANTIC SALMON; GENETIC DIFFERENTIATION; MUTATIONAL PROCESSES; COMPUTER-PROGRAM; RAINBOW-TROUT; LOCI; CONSERVATION AB Single nucleotide polymorphisms ( SNPs) are appealing genetic markers due to several beneficial attributes, but uncertainty remains about how many of these bi-allelic markers are necessary to have sufficient power to differentiate populations, a task now generally accomplished with highly polymorphic microsatellite markers. In this study, we tested the utility of 37 SNPs and 13 microsatellites for differentiating 29 broadly distributed populations of Chinook salmon (n = 2783). Information content of all loci was determined by In and, and the top 12 markers ranked by In were microsatellites, but the 6 highest, and 7 of the top 10 ranked markers, were SNPs. The mean ratio of random SNPs to random microsatellites ranged from 3.9 to 4.1, but this ratio was consistently reduced when only the most informative loci were included. Individual assignment test accuracy was higher for microsatellites (73.1%) than SNPs (66.6%), and pooling all 50 markers provided the highest accuracy (83.2%). When marker types were combined, as few as 15 of the top ranked loci provided higher assignment accuracy than either microsatellites or SNPs alone. Neighbour-joining dendrograms revealed similar clustering patterns and pairwise tests of population differentiation had nearly identical results with each suite of markers. Statistical tests and simulations indicated that closely related populations were better differentiated by microsatellites than SNPs. Our results indicate that both types of markers are likely to be useful in population genetics studies and that, in some cases, a combination of SNPs and microsatellites may be the most effective suite of loci. C1 Columbia River Intertribal Fish Commiss, Hagerman Fish Culture Expt Stn, Hagerman, ID 83332 USA. Oregon State Univ, Hatfield Marine Sci Ctr, Marine Fisheries Genet Coastal Oregon Marine Expt, Newport, OR 97365 USA. Fisheries & Oceans Canada, Pacific Biol Stn, Dept Fisheries & Oceans, Nanaimo, BC V9T 6N7, Canada. Idaho Dept Fish & Game, Eagle Fish Genet Lab, Eagle, ID 83616 USA. Washington State Univ, Vancouver, WA 98686 USA. Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Natori, Miyagi 98112, Japan. Natl Marine Fisheries Serv, Auke Bay Lab, Alaska Fisheries Sci Ctr, Juneau, AK 99801 USA. Alaska Dept Fish & Game, Div Commercial Fisheries, Anchorage, AK 99518 USA. Washington Dept Fish & Wildlife, Olympia, WA 98501 USA. Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, Santa Cruz, CA 95060 USA. RP Narum, SR (reprint author), Columbia River Intertribal Fish Commiss, Hagerman Fish Culture Expt Stn, 3059-F Natl Fish Hatchery Rd, Hagerman, ID 83332 USA. EM nars@critfc.org OI Bellinger, M. Renee/0000-0001-5274-9572 NR 55 TC 82 Z9 87 U1 4 U2 37 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0962-1083 J9 MOL ECOL JI Mol. Ecol. PD AUG PY 2008 VL 17 IS 15 BP 3464 EP 3477 DI 10.1111/j.1365-294X.2008.03851.x PG 14 WC Biochemistry & Molecular Biology; Ecology; Evolutionary Biology SC Biochemistry & Molecular Biology; Environmental Sciences & Ecology; Evolutionary Biology GA 328ET UT WOS:000257781300004 PM 19160476 ER PT J AU Sim, SA Long, KS Miller, L Turner, TJ AF Sim, S. A. Long, K. S. Miller, L. Turner, T. J. TI Multidimensional modelling of X-ray spectra for AGN accretion disc outflows SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE radiative transfer; methods : numerical; galaxies : active; X-rays : galaxies ID ACTIVE GALACTIC NUCLEI; LINE SEYFERT-1 GALAXIES; PHOTOIONIZATION CROSS-SECTIONS; CARLO TRANSITION-PROBABILITIES; BLACK-HOLE WINDS; BROAD IRON LINES; SOFT EXCESS; MULTILINE TRANSFER; ABSORPTION ORIGIN; ATOMIC DATABASE AB We use a multidimensional Monte Carlo code to compute X-ray spectra for a variety of active galactic nucleus (AGN) disc-wind outflow geometries. We focus on the formation of blueshifted absorption features in the Fe K band and show that line features similar to those which have been reported in observations are often produced for lines of sight through disc-wind geometries. We also discuss the formation of other spectral features in highly ionized outflows. In particular, we show that, for sufficiently high wind densities, moderately strong Fe K emission lines can form and that electron scattering in the flow may cause these lines to develop extended red wings. We illustrate the potential relevance of such models to the interpretation of real X-ray data by comparison with observations of a well-known AGN, Mrk 766. C1 [Sim, S. A.] Max Planck Inst Astrophys, D-85748 Garching, Germany. [Long, K. S.] Space Telescope Sci Inst, Baltimore, MD 21218 USA. [Miller, L.] Univ Oxford, Dept Phys, Oxford OX1 3RH, England. [Turner, T. J.] Univ Maryland Baltimore Cty, Dept Phys, Baltimore, MD 21250 USA. [Turner, T. J.] NASA GSFC, Astrophys Sci Div, Greenbelt, MD 20771 USA. RP Sim, SA (reprint author), Max Planck Inst Astrophys, Karl Schwarzschildstr 1, D-85748 Garching, Germany. EM ssim@mpa-garching.mpg.de NR 66 TC 54 Z9 54 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 AUG 1 PY 2008 VL 388 IS 2 BP 611 EP 624 DI 10.1111/j.1365-2966.2008.13466.x PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 328EU UT WOS:000257781400009 ER PT J AU Zhang, P Feldman, HA Juszkiewicz, R Stebbins, A AF Zhang, Pengjie Feldman, Hume A. Juszkiewicz, Roman Stebbins, Albert TI A new method of measuring the cluster peculiar velocity power spectrum SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE cosmic microwave background; cosmology : observations; cosmology : theory; dark matter; distance scale; large-scale structure of Universe ID PROBE WMAP OBSERVATIONS; IA SUPERNOVAE; BULK FLOWS; GALAXIES; UNIVERSE; FIELDS; FLUCTUATIONS; STATISTICS; DENSITY; MOMENTS AB We propose to use spatial correlations of the kinetic Sunyaev-Zeldovich (KSZ) flux as an estimator of the peculiar velocity power spectrum. In contrast with conventional techniques, our new method does not require measurements of the thermal SZ signal or the X-ray temperature. Moreover, this method has the special advantage that the expected systematic errors are always subdominant to statistical errors on all scales and redshifts of interest. We show that future large sky coverage KSZ surveys may allow a peculiar velocity power spectrum estimates of an accuracy reaching similar to 10 per cent. C1 [Zhang, Pengjie] Chinese Acad Sci, Shanghai Observ, Shanghai 200030, Peoples R China. [Zhang, Pengjie; Stebbins, Albert] Fermilab Natl Accelerator Lab, NASA, Fermilab Astrophys Ctr, Batavia, IL 60510 USA. [Feldman, Hume A.] Univ Kansas, Dept Phys & Astron, Lawrence, KS 66045 USA. [Juszkiewicz, Roman] Zielona Gora Univ, Inst Astron, PL-65516 Zielona Gora, Poland. [Juszkiewicz, Roman] Copernicus Astron Ctr, PL-00716 Warsaw, Poland. RP Zhang, P (reprint author), Chinese Acad Sci, Shanghai Observ, Shanghai 200030, Peoples R China. EM pjzhang@shao.ac.cn; feldman@ku.edu; roman@camk.edu.pl; stebbins@fnal.gov RI ZHANG, PENGJIE/O-2825-2015 NR 49 TC 7 Z9 7 U1 0 U2 1 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD AUG 1 PY 2008 VL 388 IS 2 BP 884 EP 888 DI 10.1111/j.1365-2966.2008.13454.x PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 328EU UT WOS:000257781400033 ER PT J AU Keppenne, CL Rienecker, MM Jacob, JP Kovach, R AF Keppenne, Christian L. Rienecker, Michele M. Jacob, Jossy P. Kovach, Robin TI Error covariance modeling in the GMAO ocean ensemble Kalman filter SO MONTHLY WEATHER REVIEW LA English DT Article ID ATMOSPHERIC DATA ASSIMILATION; SEQUENTIAL DATA ASSIMILATION; GENERAL-CIRCULATION MODEL; PACIFIC-OCEAN; TEMPERATURE; PREDICTION; FLUX; BIAS AB In practical applications of the ensemble Kalman filter (EnKF) for ocean data assimilation, the computational burden and memory limitations usually require a trade-off between ensemble size and model resolution. This is certainly true for the NASA Global Modeling and Assimilation Office (GMAO) ocean EnKF used for ocean climate analyses. The importance of resolution for the adequate representation of the dominant current systems means that small ensembles, with their concomitant sampling biases, have to be used. Hence, strategies have been sought to address sampling problems and to improve the performance of the EnKF for a given ensemble size. Approaches assessed herein consist of spatiotemporal filtering of background-error covariances, improving the system-noise representation, imposing a steady-state error covariance model, and speeding up the analysis by performing the most expensive operation of the analysis on a coarser computational grid. A judicious combination of these approaches leads to significant performance improvements, especially with very small ensembles. C1 [Keppenne, Christian L.; Rienecker, Michele M.; Jacob, Jossy P.; Kovach, Robin] NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Greenbelt, MD 20771 USA. [Keppenne, Christian L.; Jacob, Jossy P.; Kovach, Robin] Sci Applicat Int Corp, Beltsville, MD USA. RP Keppenne, CL (reprint author), NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Code 610-1, Greenbelt, MD 20771 USA. EM christian.keppenne@nasa.gov NR 23 TC 22 Z9 22 U1 0 U2 0 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 AUG PY 2008 VL 136 IS 8 BP 2964 EP 2982 DI 10.1175/2007MWR2243.1 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 337QN UT WOS:000258450700008 ER PT J AU Wei, J Olaya, D Karasik, BS Pereverzev, SV Sergeev, AV Gershenson, ME AF Wei, Jian Olaya, David Karasik, Boris S. Pereverzev, Sergey V. Sergeev, Andrei V. Gershenson, Michael E. TI Ultrasensitive hot-electron nanobolometers for terahertz astrophysics SO NATURE NANOTECHNOLOGY LA English DT Article ID DETECTOR; QUANTUM; SAFIR; HEAT AB The submillimetre or terahertz region of the electromagnetic spectrum contains approximately half of the total luminosity of the Universe and 98% of all the photons emitted since the Big Bang(1). This radiation is strongly absorbed in the Earth's atmosphere, so space-based terahertz telescopes are crucial for exploring the evolution of the Universe(2,3). Thermal emission from the primary mirrors in these telescopes can be reduced below the level of the cosmic background by active cooling, which expands the range of faint objects that can be observed. However, it will also be necessary to develop bolometers devices for measuring the energy of electromagnetic radiation-with sensitivities that are at least two orders of magnitude better than the present state of the art. To achieve this sensitivity without sacrificing operating speed, two conditions are required. First, the bolometer should be exceptionally well thermally isolated from the environment; second, its heat capacity should be sufficiently small. Here we demonstrate that these goals can be achieved by building a superconducting hot-electron nanobolometer. Its design eliminates the energy exchange between hot electrons and the leads by blocking electron outdiffusion and photon emission. The thermal conductance between hot electrons and the thermal bath, controlled by electron-phonon interactions, becomes very small at low temperatures (similar to 1 x 10(-16) W K(-1) at 40 mK). These devices, with a heat capacity of similar to 1 x 10(-19) J K(-1), are sufficiently sensitive to detect single terahertz photons in submillimetre astronomy and other applications based on quantum calorimetry and photon counting. C1 [Wei, Jian; Olaya, David; Pereverzev, Sergey V.; Gershenson, Michael E.] Rutgers State Univ, Dept Phys & Astron, Piscataway, NJ 08854 USA. [Karasik, Boris S.; Pereverzev, Sergey V.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Sergeev, Andrei V.] SUNY Buffalo, Buffalo, NY 14260 USA. RP Wei, J (reprint author), Rutgers State Univ, Dept Phys & Astron, 136 Frelinghuysen Rd, Piscataway, NJ 08854 USA. EM boris.s.karasik@jpl.nasa.gov; gersh@physics.rutgers.edu RI Wei, Jian/B-2137-2014 OI Wei, Jian/0000-0002-8831-6418 NR 28 TC 104 Z9 107 U1 5 U2 22 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 1748-3387 J9 NAT NANOTECHNOL JI Nat. Nanotechnol. PD AUG PY 2008 VL 3 IS 8 BP 496 EP 500 DI 10.1038/nnano.2008.173 PG 5 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary SC Science & Technology - Other Topics; Materials Science GA 335WZ UT WOS:000258325800015 PM 18685638 ER PT J AU Lansbergen, GP Rahman, R Wellard, CJ Woo, I Caro, J Collaert, N Biesemans, S Klimeck, G Hollenberg, LCL Rogge, S AF Lansbergen, G. P. Rahman, R. Wellard, C. J. Woo, I. Caro, J. Collaert, N. Biesemans, S. Klimeck, G. Hollenberg, L. C. L. Rogge, S. TI Gate-induced quantum-confinement transition of a single dopant atom in a silicon FinFET SO NATURE PHYSICS LA English DT Article ID ATOMISTIC SIMULATION; NEMO 3-D; COMPUTER; REALIZATION; DEVICES; DONORS; STATES; DOTS AB The ability to build structures with atomic precision is one of the defining features of nanotechnology. Achieving true atomic- level functionality, however, requires the ability to control the wavefunctions of individual atoms. Here, we investigate an approach that could enable just that. By collecting and analysing transport spectra of a single donor atom in the channel of a silicon FinFET, we present experimental evidence for the emergence of a new type of hybrid molecule system. Our experiments and simulations suggest that the transistor's gate potential can be used to control the degree of hybridization of a single electron donor state between the nuclear potential of its donor atom and a nearby quantum well. Moreover, our theoretical analysis enables us to determine the species of donor (arsenic) implanted into each device as well as the degree of confinement imposed by the gate. C1 [Lansbergen, G. P.; Caro, J.; Rogge, S.] Delft Univ Technol, Kavli Inst Nanosci, NL-2628 CJ Delft, Netherlands. [Rahman, R.; Woo, I.; Klimeck, G.] Purdue Univ, Network Computat Nanotechnol, W Lafayette, IN 47907 USA. [Wellard, C. J.; Hollenberg, L. C. L.] Univ Melbourne, Ctr Quantum Comp Technol, Sch Phys, Melbourne, Vic 3010, Australia. [Collaert, N.; Biesemans, S.] IMEC, B-3001 Louvain, Belgium. [Klimeck, G.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Lansbergen, GP (reprint author), Delft Univ Technol, Kavli Inst Nanosci, Lorentzweg 1, NL-2628 CJ Delft, Netherlands. EM G.P.Lansbergen@tudelft.nl RI Hollenberg, Lloyd/B-2296-2010; Fonseca, James/G-1018-2011; Lansbergen, Gabriel/A-7895-2011; Klimeck, Gerhard/A-1414-2012; Rogge, Sven/G-3709-2010; OI Klimeck, Gerhard/0000-0001-7128-773X; Rahman, Rajib/0000-0003-1649-823X NR 43 TC 212 Z9 213 U1 5 U2 90 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 1745-2473 J9 NAT PHYS JI Nat. Phys. PD AUG PY 2008 VL 4 IS 8 BP 656 EP 661 DI 10.1038/nphys994 PG 6 WC Physics, Multidisciplinary SC Physics GA 335XB UT WOS:000258326000020 ER PT J AU Weber, AL AF Weber, Arthur L. TI Sugar-driven prebiotic synthesis of 3,5(6)-dimethylpyrazin-2-one: A possible nucleobase of a primitive replication process SO ORIGINS OF LIFE AND EVOLUTION OF BIOSPHERES LA English DT Article DE sugar chemistry; glyceraldehyde; pyrazinone synthesis; sugar-amine reaction; alanine amide; template replication; nucleobase synthesis; prebiotic chemistry; origin of life ID MILD AQUEOUS CONDITIONS; MAILLARD REACTION; EARLY EARTH; RNA WORLD; ORIGIN; CHEMISTRY; AMMONIA; MODEL; LIFE; ATMOSPHERE AB Reaction of glyceraldehyde with alanine amide (or ammonia) under anaerobic aqueous conditions yielded 3,5(6)-dimethylpyrazin-2-one that is considered a possible complementary residue of a primitive replicating molecule that preceded RNA. Synthesis of the dimethylpyrazin-2-one isomers under mild aqueous conditions (65 degrees C, pH 5.5) from 100 mM glyceraldehyde and alanine amide (or ammonia) was complete in about 5 days. This synthesis using 25 mM glyceraldehyde and alanine amide gave a total pyrazinone yield of 9.3% consisting of 42% of the 3,5-dimethylprazin-2-one isomer and 58% of the 3,6-dimethylpyrazin-2-one isomer. The related synthesis of the dimethylpyrazin-2-one isomers from glyceraldehyde and ammonia was about 200-fold less efficient than the alanine amide reaction. This synthetic process is considered a reasonable model of origin-of-life chemistry because it uses plausible prebiotic substrates, and resembles modern biosynthesis by employing the energized carbon groups of sugars to drive the synthesis of small organic molecules. Possible sugar-driven pathways for the prebiotic synthesis of polymerizable 2-pyrazinone monomers are discussed. C1 NASA, Ames Res Ctr, SETI Inst, Moffett Field, CA 94035 USA. RP Weber, AL (reprint author), NASA, Ames Res Ctr, SETI Inst, Mail Stop 239-4, Moffett Field, CA 94035 USA. EM Arthur.L.Weber@nasa.gov NR 52 TC 11 Z9 11 U1 0 U2 6 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0169-6149 J9 ORIGINS LIFE EVOL B JI Orig. Life Evol. Biosph. PD AUG PY 2008 VL 38 IS 4 BP 279 EP 292 DI 10.1007/s11084-008-9141-6 PG 14 WC Biology SC Life Sciences & Biomedicine - Other Topics GA 322SP UT WOS:000257395900001 PM 18581252 ER PT J AU Parkinson, CD Liang, MC Yung, YL Kirschivnk, JL AF Parkinson, Christopher D. Liang, Mao-Chang Yung, Yuk L. Kirschivnk, Joseph L. TI Habitability of Enceladus: Planetary conditions for life SO ORIGINS OF LIFE AND EVOLUTION OF BIOSPHERES LA English DT Article DE astrobiology; geochemical cycle; habitability; icy moons; microphysical cloud physics; plume; tectonic processes; tiger stripes ID WATER-VAPOR PLUME; EUROPA; CASSINI; ATMOSPHERE; MODEL; ANALOGS; ORIGIN; OCEAN AB The prolific activity and presence of a plume on Saturn's tiny moon Enceladus offers us a unique opportunity to sample the interior composition of an icy satellite, and to look for interesting chemistry and possible signs of life. Based on studies of the potential habitability of Jupiter's moon Europa, icy satellite oceans can be habitable if they are chemically mixed with the overlying ice shell on Myr time scales. We hypothesize that Enceladus' plume, tectonic processes, and possible liquid water ocean may create a complete and sustainable geochemical cycle that may allow it to support life. We discuss evidence for surface/ocean material exchange on Enceladus based on the amounts of silicate dust material present in the Enceladus' plume particles. Microphysical cloud modeling of Enceladus' plume shows that the particles originate from a region of Enceladus' near surface where the temperature exceeds 190 K. This could be consistent with a shear-heating origin of Enceladus' tiger stripes, which would indicate extremely high temperatures (similar to 250-273 K) in the subsurface shear fault zone, leading to the generation of subsurface liquid water, chemical equilibration between surface and subsurface ices, and crustal recycling on a time scale of 1 to 5 Myr. Alternatively, if the tiger stripes form in a mid-ocean-ridge-type mechanism, a half-spreading rate of 1 m/year is consistent with the observed regional heat flux of 250 mW m(-2) and recycling of south polar terrain crust on a 1 to 5 Myr time scale as well. C1 [Parkinson, Christopher D.] Univ Michigan, Dept Atmospher Ocean & Space Sci, Ann Arbor, MI 48109 USA. [Liang, Mao-Chang; Yung, Yuk L.; Kirschivnk, Joseph L.] CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. [Liang, Mao-Chang] Acad Sinica, Res Ctr Environm Changes, Taipei 115, Taiwan. [Liang, Mao-Chang] Natl Cent Univ, Grad Inst Astron, Jhongli, Taiwan. [Yung, Yuk L.] CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RP Parkinson, CD (reprint author), Univ Michigan, Dept Atmospher Ocean & Space Sci, 2455 Hayward St, Ann Arbor, MI 48109 USA. EM cdp@gps.caltech.edu NR 41 TC 22 Z9 22 U1 6 U2 37 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0169-6149 J9 ORIGINS LIFE EVOL B JI Orig. Life Evol. Biosph. PD AUG PY 2008 VL 38 IS 4 BP 355 EP 369 DI 10.1007/s11084-008-9135-4 PG 15 WC Biology SC Life Sciences & Biomedicine - Other Topics GA 322SP UT WOS:000257395900006 PM 18566911 ER PT J AU Raj, SV AF Raj, S. V. TI Comparison of the isothermal oxidation behavior of as-cast Cu-17%Cr and Cu-17%Cr-5%Al part I: Oxidation kinetics SO OXIDATION OF METALS LA English DT Article DE isothermal oxidation; Cu-Cr alloys; Cu-Cr-Al; copper alloys; oxidation kinetics ID CU-CR ALLOYS; HIGH-TEMPERATURE OXIDATION; COPPER-ALLOYS; CUPROUS-OXIDE; ATM O-2; AL; 700-900-DEGREES-C; RESISTANCE; DIFFUSION; ALUMINUM AB The isothermal oxidation kinetics of as-cast Cu-17%Cr and Cu-17%Cr-5%Al in air were studied between 773 and 1,173 K under atmospheric pressure. These observations reveal that Cu-17%Cr-5%Al oxidizes at significantly slower rates than Cu-17%Cr. The rate constants for the alloys were determined from generalized analyses of the data without an a priori assumption of the nature of the oxidation kinetics. Detailed analyses of the isothermal thermogravimetric weight change data revealed that Cu-17%Cr exhibited parabolic oxidation kinetics with an activation energy of 165.9 +/- 9.5 kJ/mol. In contrast, the oxidation kinetics for the Cu-17%Cr-5%Al alloy exhibited a parabolic oxidation kinetics during the initial stages followed by a quartic relationship in the later stages of oxidation. Alternatively, the oxidation behavior of Cu-17%Cr-5%Al could be better represented by a logarithmic relationship. The parabolic rate constants and activation energy data for the two alloys are compared with literature data to gain insights on the nature of the oxidation mechanisms dominant in these alloys. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Raj, SV (reprint author), NASA, Glenn Res Ctr, MS 106-5,21000 Brookpk Rd, Cleveland, OH 44135 USA. EM sai.v.raj@nasa.gov NR 54 TC 4 Z9 4 U1 0 U2 1 PU SPRINGER/PLENUM PUBLISHERS PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0030-770X J9 OXID MET JI Oxid. Met. PD AUG PY 2008 VL 70 IS 1-2 BP 85 EP 102 DI 10.1007/s11085-008-9110-5 PG 18 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA 323RI UT WOS:000257465400006 ER PT J AU Raj, SV AF Raj, S. V. TI Comparison of the isothermal oxidation behavior of as-cast Cu-17%Cr and Cu-17%Cr-5%Al. Part II: Scale microstructures SO OXIDATION OF METALS LA English DT Article DE isothermal oxidation; Cu-Cr alloys; Cu-Cr-Al; copper alloys; oxidation kinetics ID COPPER; ALLOYS; TEMPERATURES; AL AB The isothermal oxidation kinetics of as-cast Cu-17%Cr and Cu-17%Cr-5%Al in air were studied between 773 and 1,173 K under atmospheric pressure. Details of the oxidation kinetics of these alloys were discussed in Part I. This paper analyzes the microstructures of the scale and its composition in an attempt to elucidate the oxidation mechanisms in these alloys. The scales formed on Cu-17%Cr specimens oxidized between 773 and 973 K consisted of external CuO and subsurface Cu(2)O layers. The total thickness of these scales varied from about 10 mu m at 773 K to about 450 mu m at 973 K. In contrast, thin scales formed on Cu-17%Cr-5%Al alloys oxidized between 773 and 1,173 K. The exact nature of these scales could not be determined by X-ray diffraction but energy dispersive spectroscopy analyses were used to construct a scale composition map. Phenomenological oxidation mechanisms are proposed for the two alloys. C1 [Raj, S. V.] NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Raj, SV (reprint author), NASA, Glenn Res Ctr, MS 106-5,21000 Brookpk Rd, Cleveland, OH 44135 USA. EM sai.v.raj@nasa.gov NR 17 TC 3 Z9 4 U1 0 U2 1 PU SPRINGER/PLENUM PUBLISHERS PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0030-770X J9 OXID MET JI Oxid. Met. PD AUG PY 2008 VL 70 IS 1-2 BP 103 EP 119 DI 10.1007/s11085-008-9104-3 PG 17 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA 323RI UT WOS:000257465400007 ER PT J AU Florescu, L AF Florescu, Lucia TI Nonclassical light generation by a photonic-crystal one-atom laser SO PHYSICAL REVIEW A LA English DT Article ID BAND-GAP; SPONTANEOUS EMISSION; RESONANCE FLUORESCENCE; QUANTUM ELECTRODYNAMICS; OPTICAL CAVITY; EDGE; STATISTICS; ABSORPTION; NANOCAVITY; INVERSION AB We investigate the effects of sub-Poissonian photon statistics and photon antibunching in the light generation by a photonic-crystal one-atom laser. The physical system consists of a two-level light emitter strongly coupled to a high-quality microcavity engineered within a photonic crystal and coherently driven by a strong external laser field. This study reveals that the electromagnetic environment provided by the photonic crystal facilitates light generation characterized by pronounced sub-Poissonian photon statistics and photon antibunching, and strongly enhanced relative to that from a one-atom laser in a conventional optical cavity. The characteristics of the cavity photon statistics are fundamentally distinct from those of a corresponding microcavity in ordinary vacuum. For large discontinuities in the photon density of states between Mollow spectral components of atomic resonance fluorescence, in the good cavity regime, the photon statistics is sub-Poissonian, in contrast to the case of a conventional cavity where sub-Poissonian photon statistics is present only for a bad cavity. These results suggest the possibility of using a photonic-crystal one-atom laser as an efficient source of nonclassical light. C1 [Florescu, Lucia] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Florescu, L (reprint author), Univ Penn, Dept Bioengn, Philadelphia, PA 19104 USA. FU National Aeronautics and Space Administration (NASA); National Research Council FX This work was performed at Jet Propulsion Laboratory, California Institute of Technology under contract with National Aeronautics and Space Administration (NASA). The author acknowledges support from the National Research Council and NASA, Code S. NR 48 TC 9 Z9 9 U1 2 U2 3 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 AUG PY 2008 VL 78 IS 2 AR 023827 DI 10.1103/PhysRevA.78.023827 PN B PG 11 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 349EG UT WOS:000259263500077 ER PT J AU Abbott, B Abbott, R Adhikai, R Agresti, J Ajith, P Allen, B Amin, R Anderson, SB Anderson, WG Arain, M Araya, M Armandula, H Ashley, M Aston, S Aufmuth, P Aulbert, C Babak, S Ballmer, S Bantilan, H Barish, BC Barker, C Barker, D Barr, B Barriga, P Barton, MA Bayer, K Betzwieser, J Beyersdorf, PT Bhawal, B Bilenko, IA Billingsley, G Biswas, R Black, E Blackburn, K Blackburn, L Blair, D Bland, B Bogenstahl, J Bogue, L Bork, R Boschi, V Bose, S Brad, PR Braginsky, VB Brau, JE Brinkmann, M Brooks, A Brown, DA Bullington, A Bunkowski, A Buonanno, A Burmeister, O Busby, D Byer, RL Cadonati, L Cagnoli, G Camp, JB Cannizzo, J Cannon, K Cantley, CA Cao, J Cardenas, L Castaldi, G Cepeda, C Chalkley, E Charlton, P Chatterji, S Chelkowski, S Chen, Y Chiadini, F Christensen, N Clark, J Cochrane, P Cokelaer, T Coldwel, R Conte, R Cook, D Corbitt, T Coyne, D Creighton, JDE Croce, RP Crooks, DRM Cruise, AM Cumming, A Dalrymple, J D'Ambrosio, E Danzmann, K Davies, G Debra, D Degallaix, J Degree, M Demma, T Dergachev, V Desai, S DeSalvo, R Dhurandhar, S Diaz, M Dickson, J Di Credico, A Diederichs, G Dietz, A Doomes, EE Drever, RWP Dumas, JC Dupuis, RJ Dwyer, JG Ehrens, P Espinoza, E Etzel, T Evans, M Evans, T Fairhurst, S Fan, Y Fazi, D Fejer, MN Finn, LS Fiumara, V Fotopoulos, N Franzen, A Franzen, KY Freise, A Frey, R Fricke, T Fritschel, P Frolov, VV Fyffe, M Galdi, V Garofoli, J Gholami, I Giaime, JA Giampanis, S Giardina, KD Goda, K Goetz, E Goggin, LM Gonzalez, G Gossler, S Grant, A Gras, S Gray, C Gray, M Greenhalgh, J Gretarsson, AM Grosso, R Grote, H Grunewald, S Guenther, M Gustafson, R Hage, B Hammer, D Hanna, C Hanson, J Harms, J Harry, G Harstad, E Hayler, T Heefner, J Heng, IS Heptonstall, A Heurs, M Hewitson, M Hild, S Hirose, E Hoak, D Hosken, D Hough, J Hoyland, D Huttner, SH Ingram, D Innerhofer, E Ito, M Itoh, Y Ivanov, A Johnson, B Johnson, WW Jones, DI Jones, G Jones, R Ju, L Kalmus, P Kalogera, V Kasprzyk, D Katsavounidis, E Kawabe, K Kawamura, S Kawazoe, F Kells, W Keppel, DG Khalili, FY Kim, C King, P Kissel, JS Klimenko, S Kokeyama, K Kondrashov, V Kopparapu, RK Kozak, D Krishnan, B Kwee, P Lam, PK Landry, M Lantz, B Lazzarini, A Lei, M Leiner, J Leonhardt, V Leonor, I Libbrecht, K Lindquist, P Lockerbie, NA Longo, M Lormand, M Lubinski, M Luck, H Machenschalk, B MacInnis, M Mageswaran, M Mailand, K Malec, M Mandic, V Marano, S Marka, S Markowitz, J Maros, E Martin, I Marx, JN Mason, K Matone, L Matta, V Mavalvala, N McCarthy, R McClelland, DE McGuire, SC McHugh, M McKenzie, K McWilliarns, S Meier, T Melissinos, A Mendell, G Mercer, RA Meshkov, S Messaritaki, E Messenger, CJ Meyers, D Mikhailov, E Mitra, S Mitrofanov, VP Mitselinakher, G Mittleman, R Miyakawa, O Mohanty, S Moreno, G Mossavi, K MowLowry, C Moylan, A Mudge, D Mueller, G Mukherjee, S Muller-Ebhardt, H Munch, J Murray, P Myers, E Myers, J Nash, T Newton, G Nishizawa, A Numata, K O'Reilly, B O'Shaughnessy, R Ottaway, DJ Overmier, H Owen, BJ Pan, Y Papa, MA Parameshwaraiah, V Patel, P Pedraza, M Penn, S Pierro, V Pinto, IM Pitkin, M Pletsch, H Plissi, MV Postiglione, F Prix, R Quetschke, V Raab, F Rabeling, D Radkins, H Rahkola, R Rainer, N Rakhmanov, M Ramsunder, M Ray-Majumder, S Re, V Rehbein, H Reid, S Reitze, DH Ribichini, L 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 Ruediger, 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, S 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 Sidles, JA Siemens, X Sigg, D Sinha, S Sintes, AM Slagmolen, BJJ Slutsky, J Smith, JR Smith, MR Somiya, K 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 Urbanek, K Vahlbruch, H Vallisneri, M Van den Broeck, C Varvella, M Vass, S Vecchio, A Veitch, J Veitch, P Villar, A Vorvick, C Vyachanin, SP Waldman, SJ Wallace, L Ward, H Ward, R Watts, K Weidner, A Weinert, M Weinstein, A Weiss, R Wen, S Wette, K Whelan, JT Whitcomb, SE Whiting, BF Wilkinson, C Willems, PA Williams, L Wilike, B Wilmut, I Winkler, W Wipf, CC Wise, S Wisernan, AG Woan, G Woods, D Wooley, R Worden, J Wu, W Yakushin, I Yamamoto, H Yan, Z Yoshida, S Yunes, N Zanolin, M Zhang, J Zhang, L Zhao, C Zotov, N Zucker, M zur Muhlen, H Zweizig, J AF Abbott, B. Abbott, R. Adhikai, R. Agresti, J. Ajith, P. Allen, B. Amin, R. Anderson, S. B. Anderson, W. G. Arain, M. Araya, M. Armandula, H. Ashley, M. 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. Bayer, K. Betzwieser, J. Beyersdorf, P. T. Bhawal, B. Bilenko, I. A. Billingsley, G. Biswas, R. Black, E. Blackburn, K. Blackburn, L. Blair, D. Bland, B. Bogenstahl, J. Bogue, L. Bork, R. Boschi, V. Bose, S. Brad, P. R. Braginsky, V. B. Brau, J. E. Brinkmann, M. Brooks, A. Brown, D. A. Bullington, A. Bunkowski, A. Buonanno, A. Burmeister, O. Busby, D. Byer, R. L. Cadonati, L. Cagnoli, G. Camp, J. B. Cannizzo, J. Cannon, K. Cantley, C. A. Cao, J. Cardenas, L. Castaldi, G. Cepeda, C. Chalkley, E. Charlton, P. Chatterji, S. Chelkowski, S. Chen, Y. Chiadini, F. Christensen, N. Clark, J. Cochrane, P. Cokelaer, T. Coldwel, R. Conte, R. Cook, D. Corbitt, T. Coyne, D. Creighton, J. D. E. Croce, R. P. Crooks, D. R. M. Cruise, A. M. Cumming, A. Dalrymple, J. D'Ambrosio, E. Danzmann, K. Davies, G. DeBra, D. Degallaix, J. Degree, M. Demma, T. Dergachev, V. Desai, S. DeSalvo, R. Dhurandhar, S. Diaz, M. Dickson, J. Di Credico, A. Diederichs, G. Dietz, A. Doomes, E. E. Drever, R. W. P. Dumas, J. -C. Dupuis, R. J. Dwyer, J. G. Ehrens, P. Espinoza, E. Etzel, T. Evans, M. Evans, T. Fairhurst, S. Fan, Y. Fazi, D. Fejer, M. N. Finn, L. S. Fiumara, V. Fotopoulos, N. Franzen, A. Franzen, K. Y. Freise, A. Frey, R. Fricke, T. Fritschel, P. Frolov, V. V. Fyffe, M. Galdi, V. Garofoli, J. Gholami, I. Giaime, J. A. Giampanis, S. Giardina, K. D. Goda, K. Goetz, E. Goggin, L. M. Gonzalez, G. Gossler, S. Grant, A. Gras, S. Gray, C. Gray, M. Greenhalgh, J. Gretarsson, A. M. Grosso, R. Grote, H. Grunewald, S. Guenther, M. Gustafson, R. Hage, B. Hammer, D. Hanna, C. Hanson, J. Harms, J. Harry, G. Harstad, E. Hayler, T. Heefner, J. Heng, I. S. Heptonstall, A. Heurs, M. Hewitson, M. Hild, S. Hirose, E. Hoak, D. Hosken, D. Hough, J. Hoyland, D. Huttner, S. H. Ingram, D. Innerhofer, E. Ito, M. Itoh, Y. Ivanov, A. Johnson, B. Johnson, W. W. Jones, D. I. Jones, G. Jones, R. Ju, L. Kalmus, P. Kalogera, V. Kasprzyk, D. Katsavounidis, E. Kawabe, K. Kawamura, S. Kawazoe, F. Kells, W. Keppel, D. G. Khalili, F. Ya. Kim, C. King, P. Kissel, J. S. Klimenko, S. Kokeyama, K. Kondrashov, V. Kopparapu, R. K. Kozak, D. Krishnan, B. Kwee, P. Lam, P. K. Landry, M. Lantz, B. Lazzarini, A. Lei, M. Leiner, J. Leonhardt, V. Leonor, I. Libbrecht, K. Lindquist, P. Lockerbie, N. A. Longo, M. Lormand, M. Lubinski, M. Lueck, H. Machenschalk, B. MacInnis, M. Mageswaran, M. Mailand, K. Malec, M. Mandic, V. Marano, S. Marka, S. Markowitz, J. Maros, E. Martin, I. Marx, J. N. Mason, K. Matone, L. Matta, V. Mavalvala, N. McCarthy, R. McClelland, D. E. McGuire, S. C. McHugh, M. McKenzie, K. McWilliarns, S. Meier, T. Melissinos, A. Mendell, G. Mercer, R. A. Meshkov, S. Messaritaki, E. Messenger, C. J. Meyers, D. Mikhailov, E. Mitra, S. Mitrofanov, V. P. Mitselinakher, G. Mittleman, R. Miyakawa, O. Mohanty, S. Moreno, G. Mossavi, K. MowLowry, C. Moylan, A. Mudge, D. Mueller, G. Mukherjee, S. Mueller-Ebhardt, H. Munch, J. Murray, P. Myers, E. Myers, J. Nash, T. Newton, G. Nishizawa, A. Numata, K. O'Reilly, B. O'Shaughnessy, R. Ottaway, D. J. Overmier, H. Owen, B. J. Pan, Y. Papa, M. A. Parameshwaraiah, V. Patel, P. Pedraza, M. Penn, S. Pierro, V. Pinto, I. M. Pitkin, M. Pletsch, H. Plissi, M. V. Postiglione, F. Prix, R. Quetschke, V. Raab, F. Rabeling, D. Radkins, H. Rahkola, R. Rainer, N. Rakhmanov, M. Ramsunder, M. Ray-Majumder, S. Re, V. Rehbein, H. Reid, S. Reitze, D. H. Ribichini, L. 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. de la Jordana, L. Sancho Sandberg, V. Sannibale, V. Saraf, S. Sarin, P. Sathyaprakash, B. S. Sato, S. Saulson, P. R. Savage, R. Savov, P. Schediwy, S. 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. Sidles, J. A. Siemens, X. Sigg, D. Sinha, S. Sintes, A. M. Slagmolen, B. J. J. Slutsky, J. Smith, J. R. Smith, M. R. Somiya, K. 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. Urbanek, K. Vahlbruch, H. Vallisneri, M. Van den Broeck, C. Varvella, M. Vass, S. Vecchio, A. Veitch, J. Veitch, P. Villar, A. Vorvick, C. Vyachanin, S. P. Waldman, S. J. Wallace, L. Ward, H. Ward, R. Watts, K. Weidner, A. 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, L. Wilike, B. Wilmut, I. Winkler, W. Wipf, C. C. Wise, S. Wisernan, A. G. Woan, G. Woods, D. Wooley, R. Worden, J. Wu, W. Yakushin, I. Yamamoto, H. Yan, Z. Yoshida, S. Yunes, N. Zanolin, M. Zhang, J. Zhang, L. Zhao, C. Zotov, N. Zucker, M. zur Muehlen, H. Zweizig, J. CA LIGO Sci Collaboration TI Search of S3 LIGO data for gravitational wave signals from spinning black hole and neutron star binary inspirals SO PHYSICAL REVIEW D LA English DT Article ID POST-NEWTONIAN ORDER; COMPACT BINARIES; CONSTRAINING POPULATION; SYNTHESIS MODELS; RADIATION; OBJECTS; FORMS; INTERFEROMETER; TEMPLATES; DETECTOR AB We report on the methods and results of the first dedicated search for gravitational waves emitted during the inspiral of compact binaries with spinning component bodies. We analyze 788 hours of data collected during the third science run (S3) of the LIGO detectors. We searched for binary systems using a detection template family specially designed to capture the effects of the spin-induced precession of the orbital plane. We present details of the techniques developed to enable this search for spin-modulated gravitational waves, highlighting the differences between this and other recent searches for binaries with nonspinning components. The template bank we employed was found to yield high matches with our spin-modulated target waveform for binaries with masses in the asymmetric range 1.0M(circle dot) < m(1) < 3.0M(circle dot) and 12.0M(circle dot) < m(2) < 20.0M(circle dot) which is where we would expect the spin of the binary's components to have a significant effect. We find that our search of S3 LIGO data has good sensitivity to binaries in the Milky Way and to a small fraction of binaries in M31 and M33 with masses in the range 1.0M(circle dot) < m(1), m(2) < 20.0M(circle dot). No gravitational wave signals were identified during this search. Assuming a binary population with spinning components and Gaussian distribution of masses representing a prototypical neutron star-black hole system with m(1) similar or equal to 1.35M(circle dot) and m(2) similar or equal to 5M(circle dot), we calculate the 90%-confidence upper limit on the rate of coalescence of these systems to be 15.9 yr(-1) L-10(-1), where L-10 is 10(10) times the blue light luminosity of the Sun. C1 [Abbott, B.; Abbott, R.; Adhikai, R.; Agresti, J.; Anderson, S. B.; Araya, M.; Armandula, H.; Ballmer, S.; Barish, B. C.; Bhawal, B.; Billingsley, G.; Black, E.; Blackburn, K.; Bork, R.; Boschi, V.; Brown, D. A.; Busby, D.; Cepeda, C.; Chatterji, S.; Coyne, D.; D'Ambrosio, E.; DeSalvo, R.; Dupuis, R. J.; Ehrens, P.; Espinoza, E.; Etzel, T.; Evans, M.; Fairhurst, S.; Fazi, D.; Goggin, L. M.; 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.; Mandic, V.; Maros, E.; Marx, J. N.; Meshkov, S.; Messaritaki, E.; Miyakawa, O.; Nash, T.; Patel, P.; Pedraza, M.; Robertson, N. A.; Russell, P.; Samidi, M.; Sannibale, V.; Sears, B.; Siemens, X.; Smith, M. R.; Sutton, P. J.; Tyler, W.; Varvella, M.; Vass, S.; Villar, A.; Waldman, S. J.; Wallace, L.; Weinstein, A.; Whitcomb, S. E.; Willems, P. A.; Yamamoto, H.; Zhang, L.; Zweizig, J.] CALTECH, LIGO, Pasadena, CA 91125 USA. [Aulbert, C.; Babak, S.; Chen, Y.; Gholami, I.; Grunewald, S.; Krishnan, B.; Machenschalk, B.; Papa, M. A.; Prix, R.; Schutz, B. F.; Sintes, A. M.; Somiya, K.; Takahashi, H.; Whelan, J. T.] Albert Einstein Inst, Max Planck Inst Gravitat Phys, D-14476 Golm, Germany. [Ajith, P.; Allen, B.; Brinkmann, M.; Bunkowski, A.; Burmeister, O.; Chelkowski, S.; Cochrane, P.; Danzmann, K.; Grote, H.; Harms, J.; Heurs, M.; Hewitson, M.; Lueck, H.; Mossavi, K.; Moylan, A.; Mueller, G.; Mueller-Ebhardt, H.; Pletsch, H.; Rainer, N.; Rehbein, H.; Ribichini, L.; Ruediger, A.; Schilling, R.; Schnabel, R.; Seifert, F.; Smith, J. R.; Somiya, K.; Weidner, A.; Weinert, M.; Wilike, B.; Winkler, W.] Albert Einstein Inst, Max Planck Inst Gravitat Phys, D-30167 Hannover, Germany. [Summerscales, T. Z.] Andrews Univ, Berrien Springs, MI 49104 USA. [Ashley, M.; Dickson, J.; Gossler, S.; Gray, M.; Lam, P. K.; McClelland, D. E.; McKenzie, K.; MowLowry, C.; Rabeling, D.; Scott, S. M.; Searle, A. C.; Slagmolen, B. J. J.; Wette, K.] Australian Natl Univ, Canberra, ACT 0200, Australia. [Drever, R. W. P.] CALTECH, Pasadena, CA 91125 USA. [Brown, D. A.; Savov, P.; Siemens, X.; Thorne, K. S.; Vallisneri, M.] Caltech CaRT, Pasadena, CA 91125 USA. [Cokelaer, T.; Davies, G.; Fairhurst, S.; Jones, G.; Robinson, C.; Romano, J. D.; Ruet, L.; Sathyaprakash, B. S.; Schutz, B. F.; Sengupta, A. S.; Van den Broeck, C.] Cardiff 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. [Dwyer, J. G.; Kalmus, P.; Marka, S.; Matone, L.; Rollins, J.] Columbia Univ, New York, NY 10027 USA. [Gretarsson, A. M.] Embry Riddle Aeronaut Univ, Prescott, AZ 86301 USA. [Penn, S.] Hobart & William Smith Coll, Geneva, NY 14456 USA. [Dhurandhar, S.; Mitra, S.] Inter Univ Ctr Astron & Astrophys, Pune 411007, Maharashtra, India. 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J.; Murray, P.; Newton, G.; Pitkin, M.; Plissi, M. V.; Reid, S.; Robertson, N. A.; Rowan, S.; Strain, K. A.; Tokmakov, K. V.; Torrie, C.; Veitch, P.; Ward, H.; Woan, G.] Univ Glasgow, Glasgow G12 8QQ, Lanark, Scotland. [Buonanno, A.; Martin, I.; Pan, Y.; Shawhan, P.] Univ Maryland, College Pk, MD 20742 USA. [Dergachev, V.; Goetz, E.; Gustafson, R.; Riles, K.; Zhang, J.] Univ Michigan, Ann Arbor, MI 48109 USA. [Brau, J. E.; Harstad, E.; Ito, M.; Leonor, I.; Rahkola, R.; Schofield, R.; Strom, D. M.] Univ Oregon, Eugene, OR 97403 USA. [Fricke, T.; Giampanis, S.; Melissinos, A.] Univ Rochester, Rochester, NY 14627 USA. [Chiadini, F.; Conte, R.; Longo, M.; Marano, S.; Matta, V.; Postiglione, F.] Univ Salerno, I-84084 Salerno, Italy. [Castaldi, G.; Croce, R. P.; Demma, T.; Galdi, V.; Pierro, V.; Pinto, I. 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. [Sidles, J. A.] Univ Washington, Seattle, WA 98195 USA. [Barriga, P.; Blair, D.; Degallaix, J.; Dumas, J. -C.; Fan, Y.; Gras, S.; Ju, L.; Schediwy, S.; Yan, Z.; Zhao, C.] Univ Western Australia, Crawley, WA 6009, Australia. [Allen, B.; Anderson, W. G.; Biswas, R.; Brad, P. R.; Cannon, K.; Creighton, J. D. E.; Hammer, D.; Papa, M. A.; Ray-Majumder, S.; Wisernan, A. G.; Woods, D.] Univ Wisconsin, Milwaukee, WI 53201 USA. [Bose, S.; Itoh, Y.; Leiner, J.; Rogan, A. M.] Washington State Univ, Pullman, WA 99164 USA. RP Abbott, B (reprint author), CALTECH, LIGO, Pasadena, CA 91125 USA. RI Kawabe, Keita/G-9840-2011; Lam, Ping Koy/A-5276-2008; Galdi, Vincenzo/B-1670-2008; McClelland, David/E-6765-2010; Martin, Iain/A-2445-2010; Hild, Stefan/A-3864-2010; Schutz, Bernard/B-1504-2010; 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; Freise, Andreas/F-8892-2011; Finn, Lee Samuel/A-3452-2009; Agresti, Juri/G-8168-2012; 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; Re, Virginia /F-6403-2013; Pitkin, Matthew/I-3802-2013; Vyatchanin, Sergey/J-2238-2012; Khalili, Farit/D-8113-2012; Chiadini, Francesco/E-1812-2015; Vecchio, Alberto/F-8310-2015; Mow-Lowry, Conor/F-8843-2015; Ottaway, David/J-5908-2015; Postiglione, Fabio/O-4744-2015; Messaritaki, Eirini/D-7393-2016; Sigg, Daniel/I-4308-2015; Pinto, Innocenzo/L-3520-2016; Harms, Jan/J-4359-2012; Frey, Raymond/E-2830-2016; Ward, Robert/I-8032-2014; Biswas, Rahul/H-7474-2016; OI Lam, Ping Koy/0000-0002-4421-601X; Galdi, Vincenzo/0000-0002-4796-3600; McClelland, David/0000-0001-6210-5842; Strain, Kenneth/0000-0002-2066-5355; Lueck, Harald/0000-0001-9350-4846; Finn, Lee Samuel/0000-0002-3937-0688; Agresti, Juri/0000-0001-6119-2470; Allen, Bruce/0000-0003-4285-6256; Zhao, Chunnong/0000-0001-5825-2401; Pitkin, Matthew/0000-0003-4548-526X; Chiadini, Francesco/0000-0002-9339-8622; Vecchio, Alberto/0000-0002-6254-1617; Postiglione, Fabio/0000-0003-0628-3796; Sigg, Daniel/0000-0003-4606-6526; Frey, Raymond/0000-0003-0341-2636; Ward, Robert/0000-0001-5503-5241; Whelan, John/0000-0001-5710-6576; Fairhurst, Stephen/0000-0001-8480-1961; Stuver, Amber/0000-0003-0324-5735; Nishizawa, Atsushi/0000-0003-3562-0990; Zweizig, John/0000-0002-1521-3397; O'Shaughnessy, Richard/0000-0001-5832-8517; Aulbert, Carsten/0000-0002-1481-8319; Freise, Andreas/0000-0001-6586-9901; MATTA, VINCENZO/0000-0002-2046-4027; MARANO, Stefano/0000-0002-5307-0980; Whiting, Bernard F/0000-0002-8501-8669; Veitch, John/0000-0002-6508-0713; Papa, M.Alessandra/0000-0002-1007-5298; LONGO, Maurizio/0000-0001-8325-4003; Pierro, Vincenzo/0000-0002-6020-5521; Boschi, Valerio/0000-0001-8665-2293; Biswas, Rahul/0000-0002-0774-8906; Pinto, Innocenzo M./0000-0002-2679-4457 FU U.S. National Science Foundation; Science and Technology Facilities Council of the United Kingdom; Max-Planck-Society; State of Niedersachsen/Germany; Australian Research Council; Council of Scientific and Industrial Research of India; Istituto Nazionale di Fisica Nucleate of Italy; Spanish Ministerio de Educacion y Ciencia; Conselleria d'Economia; Hisenda i Innovacio of the Govern de les Illes Balears; 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 FX The authors gratefully acknowledge the support of the U.S. 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 GE0600 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 Nucleate of Italy, the Spanish Ministerio de Educacion y Ciencia, the Conselleria d'Economia, Hisenda i Innovacio of the Govern de les Illes Balears, 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. NR 64 TC 45 Z9 45 U1 2 U2 11 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0010 EI 2470-0029 J9 PHYS REV D JI Phys. Rev. D PD AUG PY 2008 VL 78 IS 4 AR 042002 DI 10.1103/PhysRevD.78.042002 PG 19 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 350QP UT WOS:000259368500006 ER PT J AU Baker, JG Boggs, WD Centrella, J Kelly, BJ McWilliams, ST van Meter, JR AF Baker, John G. Boggs, William D. Centrella, Joan Kelly, Bernard J. McWilliams, Sean T. van Meter, James R. TI Mergers of nonspinning black-hole binaries: Gravitational radiation characteristics SO PHYSICAL REVIEW D LA English DT Article ID 3-DIMENSIONAL CARTESIAN GRIDS; ADAPTIVE MESH REFINEMENT; APPARENT-HORIZON FINDER; NUMERICAL RELATIVITY; EVOLUTION; EQUATION; WAVES; SPIN AB We present a detailed descriptive analysis of the gravitational radiation from black-hole binary mergers of nonspinning black holes, based on numerical simulations of systems varying from equal mass to a 6:1 mass ratio. Our primary goal is to present relatively complete information about the waveforms, including all the leading multipolar components, to interested researchers. In our analysis, we pursue the simplest physical description of the dominant features in the radiation, providing an interpretation of the waveforms in terms of an implicit rotating source. This interpretation applies uniformly to the full wave train, from inspiral through ringdown. We emphasize strong relationships among the l = m modes that persist through the full wave train. Exploring the structure of the waveforms in more detail, we conduct detailed analytic fitting of the late-time frequency evolution, identifying a key quantitative feature shared by the C = in modes, among all mass ratios. We identify relationships, with a simple interpretation in terms of the implicit rotating source, among the evolution of frequency and amplitude, which hold for the late-time radiation. These detailed relationships provide sufficient information about the late-time radiation to yield a predictive model for the late-time waveforms, an alternative to the common practice of modeling by a sum of quasinormal mode overtones. We demonstrate ail application of this in a new effective-one-body-based analytic waveform model. C1 [Baker, John G.; Centrella, Joan; Kelly, Bernard J.; McWilliams, Sean T.; van Meter, James R.] NASA, Goddard Space Flight Ctr, Gravitat Astrophys Lab, Greenbelt, MD 20771 USA. [Boggs, William D.; McWilliams, Sean T.] Univ Maryland, Dept Phys, College Pk, MD 20742 USA. RP Baker, JG (reprint author), NASA, Goddard Space Flight Ctr, Gravitat Astrophys Lab, 8800 Greenbelt Rd, Greenbelt, MD 20771 USA. RI van meter, james/E-7893-2011; Kelly, Bernard/G-7371-2011; OI Kelly, Bernard/0000-0002-3326-4454 NR 56 TC 66 Z9 66 U1 0 U2 5 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 AUG PY 2008 VL 78 IS 4 AR 044046 DI 10.1103/PhysRevD.78.044046 PG 25 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 350QP UT WOS:000259368500094 ER PT J AU Gualtieri, L Berti, E Cardoso, V Sperhake, U AF Gualtieri, Leonardo Berti, Emanuele Cardoso, Vitor Sperhake, Ulrich TI Transformation of the multipolar components of gravitational radiation under rotations and boosts SO PHYSICAL REVIEW D LA English DT Article ID KERR BLACK-HOLE; TESTING RELATIVISTIC GRAVITY; METZNER-SACHS GROUP; GENERAL RELATIVITY; WAVE OBSERVATIONS; ISOLATED SYSTEMS; PARTICLE; PERTURBATIONS; EQUATIONS; GEOMETRY AB We study the transformation of multipolar decompositions of gravitational radiation under rotations and boosts. Rotations to the remnant black hole's frame simplify the waveforms from the merger of generic spinning black hole binaries. Boosts may be important to get an accurate gravitational-wave phasing, especially for configurations leading to large recoil velocities of the remnant. As a test of the formalism we revisit the classic problem of point particles failing into a Schwarzschild black hole. Then we highlight by specific examples the importance of choosing the right frame in numerical simulations of unequal mass, spinning binary black-hole mergers. C1 [Gualtieri, Leonardo] Univ Roma La Sapienza, Dipartimento Fis, I-00185 Rome, Italy. [Gualtieri, Leonardo] Sez INFN Roma1, I-00185 Rome, Italy. [Berti, Emanuele] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. [Cardoso, Vitor] Ctr Multidisciplinar Astrofis CENTRA, Dept Fis, Inst Super Tecn, P-1049001 Lisbon, Portugal. [Cardoso, Vitor] Univ Mississippi, Dept Phys & Astron, University, MS 38677 USA. [Sperhake, Ulrich] Univ Jena, Inst Theoret Phys, D-07743 Jena, Germany. RP Gualtieri, L (reprint author), Univ Roma La Sapienza, Dipartimento Fis, PA Moro 5, I-00185 Rome, Italy. EM Leonardo.Gualtieri@roma1.infn.it; Emanuele.Berti@jpl.nasa.gov; Vitor.Cardoso@ist.utl.pt; Ulrich.Sperhake@uni-jena.de RI Gualtieri, Leonardo/F-2612-2012; Berti, Emanuele/C-9331-2016; Cardoso, Vitor/K-1877-2015 OI Berti, Emanuele/0000-0003-0751-5130; Gualtieri, Leonardo/0000-0002-1097-3266; Cardoso, Vitor/0000-0003-0553-0433 NR 68 TC 17 Z9 17 U1 0 U2 2 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 AUG PY 2008 VL 78 IS 4 AR 044024 DI 10.1103/PhysRevD.78.044024 PG 20 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 350QP UT WOS:000259368500072 ER PT J AU Sahraoui, F AF Sahraoui, F. TI Diagnosis of magnetic structures and intermittency in space-plasma turbulence using the technique of surrogate data SO PHYSICAL REVIEW E LA English DT Article ID SOLAR-WIND; PHASE COHERENCE; WAVE TURBULENCE; MHD WAVES; MAGNETOHYDRODYNAMICS; MAGNETOSHEATH; FLUCTUATIONS; CASCADE AB Intermittency is usually identified in turbulent flows as non-Gaussian tails of the probability density functions (PDFs) of the turbulent field derivatives. Here we investigate the role of phase coherence among the Fourier modes in creating intermittency in magnetized space plasmas using the technique of surrogate data. We apply the technique to two examples: (i) synthetic data and (ii) magnetic field fluctuations recorded in the terrestrial magnetosheath by the Cluster spacecraft. We use a set of four series of data, one observed and three surrogate, and their PDFs and moments (q <= 4) as discriminating statistics. We show that the technique allows for detecting coherent structures and estimating their scales. We show furthermore that the phases, but not the amplitudes, create the non-Gaussian tails of the PDFs. We show also that the surrogate data used cannot account for asymmetries of the PDFs of the observed data. This enables us to confirm a scenario of turbulent cascade of mirror structures proposed in previous publications, by showing the existence of an approximately constant energy flux in the inertial range. C1 [Sahraoui, F.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Sahraoui, F.] UVSQ, CNRS, CETP, Ctr Etude Environm Terrestre & Planetaires, F-78140 Velizy Villacoublay, France. RP Sahraoui, F (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. EM fsahraoui@pop600.gsfc.nasa.gov FU NASA Post Doctoral Program FX I gratefully acknowledge Patrick Robert (FGM team) for providing the data used in this work. I thank M. Goldstein, G. Belmont, L. Rezeau, and A. Grandin for fruitful discussions. This work has been supported, in part, by the NASA Post Doctoral Program at the Goddard Space Flight Center. NR 33 TC 23 Z9 23 U1 0 U2 2 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1539-3755 J9 PHYS REV E JI Phys. Rev. E PD AUG PY 2008 VL 78 IS 2 AR 026402 DI 10.1103/PhysRevE.78.026402 PN 2 PG 7 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 349EI UT WOS:000259263700063 PM 18850941 ER EF