HR: 0800h
AN: SA31A-0340    [Abstracts]
TI: Dependence of High-Latitude Lower Thermospheric Winds on the Interplanetary Magnetic Field
AU: * Kwak, Y
EM: ys-kwak@hanmail.net
AF: NCAR High Altitude Observatory, P.O. Box 3000, Boulder, CO 80307-3000 United States
AU: Richmond, A
EM: richmond@hao.ucar.edu
AF: NCAR High Altitude Observatory, P.O. Box 3000, Boulder, CO 80307-3000 United States
AU: Maute, A
EM: maute@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 Astronomy and Atmospheric Sciences, 1370 Sankyuk-dong, Buk-ku, Daegu, 702-701 Korea, Republic of
AB: To better understand how high-latitude electric fields influence thermospheric dynamics, we study wind in the high-latitude lower thermosphere using the Thermosphere-Ionosphere-Electrodynamics General Circulation Model of the National Center for atmospheric Research (NCAR/TIEGCM). The association of the model results with the interplanetary magnetic field (IMF) is also examined to determine the influences of the IMF on the wind. We analyze the divergence and vertical component of vorticity of the high-latitude neutral wind field in the lower thermosphere during the southern summertime for different IMF conditions. This analysis provides the determination of the large-scale vorticity and divergence patterns in the lower polar thermosphere and provides insight into the relative strengths of the different sources of momentum responsible for driving winds. And also, to determine the processes that are mainly responsible for causing strong rotational flow in the high-latitude lower thermospheric wind fields, a term analysis of vorticity equation that describes the forces that drive the rotational component of the horizontal wind is performed. We also attempt a "term analysis of the potential vorticity equation" for the high-latitude neutral wind field in the lower thermosphere. This analysis provides a quantitative insight into the contribution of the momentum forcing and the heating to the high-latitude lower thermospheric dynamics.
DE: 2427 Ionosphere/atmosphere interactions (0335)
DE: 2435 Ionospheric disturbances
DE: 2437 Ionospheric dynamics
DE: 2475 Polar cap ionosphere
DE: 3369 Thermospheric dynamics (0358)
SC: SPA-Aeronomy [SA]
MN: Fall Meeting 2005