HR: 0800h
AN: SA21C-0368    [Abstracts]
TI: High-latitude Momentum Force Balance in the Lower Thermosphere : Dependence on the Interplanetary Magnetic Field
AU: * Kwak, Y
EM: ys-kwak@hanmail.net
AF: Kyungpook National University, Department of Astronomy and Atmospheric Sciences, 1370 Sankyuk-dong, Buk-ku, Daegu, 702-701 Korea, Republic of
AU: Richmond, A
EM: richmond@hao.ucar.edu
AF: NCAR High Altitude Observatory, P.O. Box 3000, Boulder, CO 80307-3000 United States
AU: Burns, A
EM: aburns@hao.ucar.edu
AF: NCAR High Altitude Observatory, P.O. Box 3000, Boulder, CO 80307-3000 United States
AU: Wang, W
EM: wbwang@hao.ucar.edu
AF: NCAR High Altitude Observatory, P.O. Box 3000, Boulder, CO 80307-3000 United States
AU: Ahn, B
EM: bhahn@knu.ac.kr
AF: Kyungpook National University, Department of Earth Science, 1370 Sankyuk-dong, Buk-ku, Daegu, 702-701 Korea, Republic of
AB: At high-latitude lower thermospheric winds are forced primarily by non-uniform solar heating, atmospheric tides and other waves coming from below, and energy and momentum sources associated with magnetosphere-ionosphere coupling, such as the magnetospheric convective electric field and the precipitation of energetic electrons and ions into the auroral regions. To understand the physical processes that control the high-latitude lower thermospheric dynamics, we quantify the forces that mainly contribute to maintaining the high-latitude lower thermospheric wind system, and we also examine the resulting momentum force balance with the aid of the National Center for Atmospheric Research Thermosphere-Ionosphere Electrodynamics General Circulation Model (NCAR-TIEGCM). Momentum forcing is statistically analyzed in geomagnetic coordinates, and its behavior with respect to the magnitude and orientation of the interplanetary magnetic field (IMF) is further examined in this study. Differences between winds and forces for different IMF orientations are analyzed.
DE: 3369 Thermospheric dynamics (0358)
DE: 2427 Ionosphere/atmosphere interactions (0335)
DE: 2435 Ionospheric disturbances
DE: 2437 Ionospheric dynamics
DE: 2475 Polar cap ionosphere
SC: SPA-Aeronomy [SA]
MN: 2004 AGU Fall Meeting