HR: 1340h
AN: SA23A-0385    [Abstracts]
TI: Using X-ray Occultation Sounding to Detect Dynamic Atmospheric Features in the Upper Mesosphere and Lower Thermosphere
AU: * Determan, J R
EM: jdeterman@satx.rr.com
AF: George Mason University, 4400 University Ave, Fairfax, VA 22030 United States
AU: Budzien, S A
EM: budzien@nrl.navy.mil
AF: U.S. Naval Research Laboratory, 4555 Overlook Ave S.W., Washinton, DC 20375-5352 United States
AU: Ray, P S
AF: U.S. Naval Research Laboratory, 4555 Overlook Ave S.W., Washinton, DC 20375-5352 United States
AB: X-ray Occultation Sounding (XOS) is a new technique for measuring total atmospheric density in the lower thermosphere and mesopause region (70-150 km) . As bright celestial X-ray sources are occulted by the Earth's atmosphere, extinction arising from inner-shell photoionization provides density information which is independent the chemistry, ionization, and thermal states of atmospheric gases. Simplistic density retrievals using XOS have demonstrated densities roughly consistent with the NRLMSISE-00 empirical climatological atmospheric model. We present results from a more detailed retrieval algorithm that enables us to examine the differences between observed density profiles and climatological predictions. An ensemble of X-ray occultations observed with the Pulse Counter Array aboard the Rossi X-ray Timing Explorer satellite are presented. We search for heating effects caused by solar X-ray flares by correlating XOS-based densities against solar X-ray fluxes measured by the GOES satellite. We also consider how other dynamical and space weather effects might account for deviations of measured densities from climatological predictions.
DE: 3360 Remote sensing
DE: 3369 Thermospheric dynamics (0358)
DE: 2118 Energetic particles, solar
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
DE: 0360 Transmission and scattering of radiation
SC: SPA-Aeronomy [SA]
MN: 2004 AGU Fall Meeting