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Found 21 entries in the Bibliography.
Showing entries from 1 through 21
| 2019 |
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As part of its International Capabilities Assessment effort, the Community Coordinated Modeling Center initiated several working teams, one of which is focused on the validation of models and methods for determining auroral electrodynamic parameters, including particle precipitation, conductivities, electric fields, neutral density and winds, currents, Joule heating, auroral boundaries, and ion outflow. Auroral electrodynamic properties are needed as input to space weather models, to test and validate the accuracy of phys ... Robinson, Robert; Zhang, Yongliang; Garcia-Sage, Katherine; Fang, Xiaohua; Verkhoglyadova, Olga; Ngwira, Chigomezyo; Bingham, Suzy; Kosar, Burcu; Zheng, Yihua; Kaeppler, Stephen; Liemohn, Michael; Weygand, James; Crowley, Geoffrey; Merkin, Viacheslav; McGranaghan, Ryan; Mannucci, Anthony; Published by: Space Weather Published on: 01/2019 YEAR: 2019 DOI: 10.1029/2018SW002127 |
| 2015 |
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A data assimilation algorithm is used to delineate the time-dependent three-dimensional ionospheric response to the 2009 sudden stratospheric warming (SSW) event. We use the Ionospheric Data Assimilation Four-Dimensional (IDA4D) algorithm to study the global ionospheric response to the 2009 SSW. This is the first study to utilize global ionospheric measurements in a data assimilation framework to unambiguously characterize atmosphere-ionosphere coupling via tidal modifications during the 2009 SSW event. Model results reve ... Azeem, I.; Crowley, G.; Honniball, C.; Published by: Journal of Geophysical Research: Space Physics Published on: 05/2015 YEAR: 2015 DOI: 10.1002/2015JA020993 Atmospheric tides; data assimilation; ionosphere/atmosphere interactions; sudden stratospheric warming |
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Seasonal variability in global eddy diffusion and the effect on neutral density We describe a method for making single-satellite estimates of the seasonal variability in global-average eddy diffusion coefficients. Eddy diffusion values as a function of time were estimated from residuals of neutral density measurements made by the Challenging Minisatellite Payload (CHAMP) and simulations made using the thermosphere-ionosphere-mesosphere electrodynamics global circulation model (TIME-GCM). The eddy diffusion coefficient results are quantitatively consistent with previous estimates based on satellite dr ... Published by: Journal of Geophysical Research: Space Physics Published on: 04/2015 YEAR: 2015 DOI: 10.1002/2015JA021084 annual; eddy diffusion; neutral density; satellite drag; seasonal variability; semiannual |
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A new technique for remote sensing of O 2 density from 140 to 180 km Observations of molecular oxygen are difficult to make in the Earth\textquoterights atmosphere between 140 and 200 km altitude. Perhaps the most accurate measurements to date have been obtained from satellite instruments that measure solar occultations of the limb. These do provide height-resolved O2 density measurements, but the nature of this technique is such that the temporal/spatial distribution of the measurements is uneven. Here a new space-based technique is described that utilizes two bright dayglow em ... Hecht, James; Christensen, Andrew; Yee, Jeng-Hwa; Crowley, Geoff; Bishop, Rebeeca; Budzien, Scott; Stephan, Andrew; Evans, Scott; Published by: Geophysical Research Letters Published on: 01/2015 YEAR: 2015 DOI: 10.1002/2014GL062355 |
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The Global Ultraviolet Imager (GUVI) onboard the Thermosphere-Ionosphere-Mesosphere Energetics and Dynamics (TIMED) satellite senses far ultraviolet emissions from O and N2 in the thermosphere. Transformation of far ultraviolet radiances measured on the Earth limb into O, N2, and O2 number densities and temperature quantifies these responses and demonstrates the value of simultaneous altitude and geographic information. Composition and temperature variations are available from 2002 to 2007 ... Meier, R.; Picone, J.; Drob, D.; Bishop, J.; Emmert, J.; Lean, J.; Stephan, A.; Strickland, D.; Christensen, A.; Paxton, L.; Morrison, D.; Kil, H.; Wolven, B.; Woods, Thomas; Crowley, G.; Gibson, S.; Published by: Earth and Space Science Published on: 01/2015 YEAR: 2015 DOI: 10.1002/2014EA000035 airglow and aurora; remote sensing; thermosphere: composition and chemistry; thermosphere: energy deposition |
| 2014 |
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Large magnitude increases in ionospheric total electron content (TEC) that occur over 1\textendash3\ h on the dayside are a significant manifestation of the main phases of superstorms. For the largest superstorms of solar cycle 23 (based on the Dst index), ground networks of GPS receivers measured peak total electron content increases greater than a factor of 2 relative to quiet time TEC averaged over the broad latitude band \textpm40\textdegree for local times 1200\textendash1600\ LT. Near 30\textdegre ... Mannucci, A.J.; Crowley, G.; Tsurutani, B.T.; Verkhoglyadova, O.P.; Komjathy, A.; Stephens, P.; Published by: Journal of Atmospheric and Solar-Terrestrial Physics Published on: 08/2014 YEAR: 2014 DOI: 10.1016/j.jastp.2014.01.001 |
| 2011 |
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Sahai, Y.; Fagundes, P.; de Jesus, R.; de Abreu, A.; Crowley, G.; Kikuchi, T.; Huang, C.-S.; Pillat, V.; Guarnieri, F.; Abalde, J.; Bittencourt, J.; Published by: Annales Geophysicae Published on: Jan-01-2011 YEAR: 2011 DOI: 10.5194/angeo-29-919-2011 |
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A study of space shuttle plumes in the lower thermosphere Meier, R.; Stevens, Michael; Plane, John; Emmert, J.; Crowley, G.; Azeem, I.; Paxton, L.; Christensen, A.; Published by: Journal of Geophysical Research Published on: Jan-01-2011 YEAR: 2011 DOI: 10.1029/2011JA016987 |
| 2010 |
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Can molecular diffusion explain Space Shuttle plume spreading? Meier, R.; Plane, John; Stevens, Michael; Paxton, L.; Christensen, A.; Crowley, G.; Published by: Geophysical Research Letters Published on: Jan-04-2010 YEAR: 2010 DOI: 10.1029/2010GL042868 |
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Comparison of the Hill\textendashSiscoe polar cap potential theory with the Weimer and AMIE models Kelley, Michael; Crowley, Geoffrey; Weimer, Daniel; Published by: Journal of Atmospheric and Solar-Terrestrial Physics Published on: Jan-03-2010 YEAR: 2010 DOI: 10.1016/j.jastp.2009.02.011 |
| 2008 |
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Periodic modulations in thermospheric composition by solar wind high speed streams Crowley, G.; Reynolds, A.; Thayer, J.; Lei, J.; Paxton, L.; Christensen, A.; Zhang, Y.; Meier, R.; Strickland, D.; Published by: Geophysical Research Letters Published on: Jan-01-2008 YEAR: 2008 DOI: 10.1029/2008GL035745 |
| 2006 |
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Global thermosphere-ionosphere response to onset of 20 November 2003 magnetic storm Crowley, G.; Hackert, C.; Meier, R.; Strickland, D.; Paxton, L.; Pi, X.; Mannucci, A.; Christensen, A.; Morrison, D.; Bust, G.; Roble, R.; Curtis, N.; Wene, G.; Published by: Journal of Geophysical Research Published on: Jan-01-2006 YEAR: 2006 DOI: 10.1029/2005JA011518 |
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We investigate the variations in the thermosphere and ionosphere using multi-instrument observations during the April 2002 period, with a particular focus on periods during small geomagnetic disturbances. Large and long-lasting reductions in the daytime electron density were observed at midlatitudes by incoherent scatter radars, ionosondes, and GPS receivers. These reductions reached 30\textendash50\% and were observed over an extended longitudinal area. They propagated to middle latitudes (35\textendash40\textdegreeN) in ... Goncharenko, L.; Salah, J.; Crowley, G.; Paxton, L.; Zhang, Y.; Coster, A.; Rideout, W.; Huang, C.; Zhang, S.; Reinisch, B.; Taran, V.; Published by: Journal of Geophysical Research Published on: 03/2006 YEAR: 2006 DOI: 10.1029/2004JA010683 Electron density; thermospheric composition; thermospheric wind |
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Kozyra, J.; Crowley, G.; Emery, B.; Fang, X.; Maris, G.; Mlynczak, M.; Niciejewski, R.; Palo, S.; Paxton, L.; Randall, C.; Rong, P.-P.; Russell, J.; Skinner, W.; Solomon, S.; Talaat, E.; Wu, Q.; Yee, J.-H.; Published by: Published on: YEAR: 2006 DOI: 10.1029/GM16710.1029/167GM24 |
| 2005 |
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Energy transport in the thermosphere during the solar storms of April 2002 Mlynczak, Martin; Martin-Torres, Javier; Crowley, Geoff; Kratz, David; Funke, Bernd; Lu, Gang; Lopez-Puertas, Manuel; Russell, James; Kozyra, Janet; Mertens, Chris; Sharma, Ramesh; Gordley, Larry; Picard, Richard; Winick, Jeremy; Paxton, L.; Published by: Journal of Geophysical Research Published on: Jan-01-2005 YEAR: 2005 DOI: 10.1029/2005JA011141 |
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The NASA TIMED/GUVI experiment obtained unprecedented far ultraviolet images of thermospheric composition and temperature during the intense geomagnetic storm on 20\textendash21 November 2003. Geographic maps of the atomic oxygen to molecular nitrogen column density ratio show severe depletions that extend to the equator near the peak of the storm. This ratio is a key indicator of how the thermospheric composition is disrupted at high latitudes and how the perturbed air moves globally as a result of dynamical forcing. For ... Meier, R.; Crowley, G.; Strickland, D.; Christensen, A.; Paxton, L.; Morrison, D.; Hackert, C.; Published by: Journal of Geophysical Research Published on: 09/2005 YEAR: 2005 DOI: 10.1029/2004JA010990 dayglow; geomagnetic storm; GUVI; remote sensing; thermospheric composition; TIMED |
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Global Thermosphere-Ionosphere Response to Geomagnetic Storms Crowley, G.; Hackert, C.; Meier, R.; Strickland, D.; Paxton, L.; Pi, X.; Manucci, A.; Christensen, A.; Morrison, D.; Bust, G.; Roble, R.; Curtis, N.; Published by: Published on: |
| 2004 |
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Quiet-time seasonal behavior of the thermosphere seen in the far ultraviolet dayglow The TIMED/GUVI instrument is a far ultraviolet spectrograph that obtains images in five spectrally resolved wavelength channels. These images yield information on the dayside composition, temperature, solar EUV flux, large-scale wave structures, and auroral processes. In this paper we present an overview analysis of Earth-disk images for four seasons (March, July, and September 2002 and January 2003). Days were selected during geomagnetically quiet periods when the Sun was nearly in the orbital plane (noon orbits). Two of ... Strickland, D.; Meier, R.; Walterscheid, R.; Christensen, A.; Paxton, L.; Morrison, D.; Craven, J.; Crowley, G.; Published by: Journal of Geophysical Research Published on: 01/2004 YEAR: 2004 DOI: 10.1029/2003JA010220 far ultraviolet; remote sensing; seasonal behavior; thermosphere |
| 2003 |
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The use of far ultraviolet remote sensing to monitor space weather This paper discusses the connection between changes in Earth\textquoterights thermosphere and ionosphere induced by changes in the Earth\textquoterights local space environment (or \textquotedblleftspace weather\textquotedblright) and the phenomena observed in far ultraviolet images of the Earth. Two new experiments, the Global Ultraviolet Imager (GUVI) and the Special Sensor Ultraviolet Imager (SSUSI), will provide a new capability for monitoring changes in thermospheric composition and ionospheric density as they change ... Paxton, L.; Morrison, Daniel; Strickland, Douglas; McHarg, M.Geoff; Zhang, Yongliang; Wolven, Brian; Kill, Hyosub; Crowley, Geoff; Christensen, Andrew; Meng, Ching-I; Published by: Advances in Space Research Published on: Jan-01-2003 YEAR: 2003 DOI: 10.1016/S0273-1177(02)00886-4 |
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Initial observations with the Global Ultraviolet Imager (GUVI) in the NASA TIMED satellite mission The Global Ultraviolet Imager (GUVI) instrument carried aboard the NASA TIMED satellite measures the spectral radiance of the Earth\textquoterights far ultraviolet airglow in the spectral region from 120 to 180 nm using a cross-track scanning spectrometer design. Continuous operation of the instrument provides images of the Earth\textquoterights disk and limb in five selectable spectral bands. Also, spectra at fixed scanning mirror position can be obtained. Initial results demonstrate the quantitative functionality of the ... Christensen, AB; Paxton, LJ; Avery, S; Craven, J; Crowley, G; Humm, DC; Kil, H; Meier, RR; Meng, C-I; Morrison, D; , others; Published by: Journal of Geophysical Research: Space Physics (1978\textendash2012) Published on: YEAR: 2003 DOI: 10.1029/2003JA009918 airglow; AURORA; ultraviolet; imaging; satellite; atmosphere |
| 2000 |
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The Use of Far Ultraviolet Remote Sensing to Monitor Space Weather Paxton, L.; Morrison, D.; Strickland, D.; McHarg, M.; Zhang, Y.; Wolven, B.; Kil, H.; Crowley, G.; Christensen, A.; Meng, C.-I; Published by: COSPAR Adv. Space Research Published on: |
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