HR: 1330h
AN: SM32B-1164    [PDF]
TI: Global Thermosphere Density Response During the May 27 - June 4, 2003 Storm Interval From CHAMP Accelerometer Measurements
AU: * Sutton, E K
EM: Eric.Sutton@colorado.edu
AF: Colorado Center for Astrodynamic Research, University of Colorado Campus Box 431, Boulder, CO 80309 United States
AU: Nerem, R S
EM: nerem@colorado.edu
AF: Colorado Center for Astrodynamic Research, University of Colorado Campus Box 431, Boulder, CO 80309 United States
AU: Forbes, J M
EM: Forbes@colorado.edu
AF: Colorado Center for Astrodynamic Research, University of Colorado Campus Box 431, Boulder, CO 80309 United States
AB: Measurements of atmospheric density from the CHAMP satellite near 410 km are used to illustrate the dependence of seasonal, latitudinal, and day/night response of the thermospheric region to elevated levels of magnetic activity. The latitude vs. time evolutions of total mass density at local times near 03:00 and 15:00 hours are elucidated from accelerometer measurements on the CHAMP satellite. These results are compared with density predictions from the NRLMSISE-00 empirical density model. Zonal winds near the equator along with polar north/south winds are analyzed using cross-track accelerometer measurements from CHAMP. The time period considered includes a significant geomagnetic storm from May 27 to June 4, 2003, which exhibits elevated magnetic activity of approximately Kp $\sim$ 5-8. Response during this storm is compared to typical quiet-time behavior during May and June (Kp $\sim$ 1-2). This time interval provides an opportunity to examine the equatorward penetration of storm-induced disturbances under conditions where the mean solar-driven summer-to-winter solstitial circulation, and the circulations driven by high-latitude heating, reinforce and oppose each other in opposite hemispheres. We find a number of orbits to be characterized by 100-1000 km-scale structures, suggesting the presence of aurorally-generated waves. Day/night differences in the equatorward penetration of both global-scale and small-scale density perturbations are also examined in terms of diurnal variations in the solar-driven meridional flow.
DE: 0355 Thermosphere--composition and chemistry
SC: SPA - Magnetospheric Physics [SM]
MN: 2003 Fall Meeting