HR: 12:05h
AN: SM11D-07    [PDF]
TI: Role of Ion-drag Processes in the Nighttime, Low-latitude Thermospheric Wind and Temperature Structure
AU: * Maruyama, N
EM: naomi@ucar.edu
AF: High Altitude Observatory, NCAR, P.O. Box 3000, Boulder, CO 80307-3000 United States
AU: Fuller-Rowell, T J
EM: Tim.Fuller-Rowell@noaa.gov
AF: Space Environment Center, NOAA and CIRES, Univ of Colorado, 325 Broadway, Boulder, CO 80305 United States
AU: Codrescu, M
EM: Mihail.Codrescu@noaa.gov
AF: Space Environment Center, NOAA and CIRES, Univ of Colorado, 325 Broadway, Boulder, CO 80305 United States
AU: Richmond, A D
EM: richmond@hao.ucar.edu
AF: High Altitude Observatory, NCAR, P.O. Box 3000, Boulder, CO 80307-3000 United States
AU: Millward, G
EM: george@apl.ucl.ac.uk
AF: Atmospheric Physics Laboratory, University College London, 67-73 Riding House Street, London, W1W 7EJ United Kingdom
AB: The purpose of this study is to understand the role of the plasmasphere in equatorial electrodynamics, with a focus on the role of ion-drag processes in the nighttime low-latitude thermospheric structure. This study utilizes the Coupled Thermosphere-Ionosphere-Plasmasphere-Electrodynamics (CTIPe) model where the equatorial plasmasphere is self-consistently coupled to the electrodynamics and the global ionosphere and thermosphere system. Ion-drag processes play a significant role in the momentum and energy interactions between the ionized and neutral species. Comprehensive elucidation of the spatial and temporal variations of the 3-dimensional ion-drag, especially in the evening prereversal enhancement of the zonal electric field, requires a self-consistent plasmaspheric distribution together with the electrodynamics and polarization fields associated with the E- and F-layer dynamo. Furthermore, the impact of ion-drag parallel to the field-lines must be considered, since the parallel ion drag in the vicinity of a pronounced Equatorial Ionization Anomaly has a significant impact on the latitudinal structure of the equatorial thermospheric structure. In this study, the mechanism responsible for the latitudinal structure of neutral wind and temperature, such as Equatorial Temperature and Wind Anomaly, Midnight Temperature Maximum and superrotation of the Earth's upper atmosphere, is addressed. The model results indicate that the ion-drag variations derived from the interacting plasmasphere and electrodynamics is an important consideration in these phenomena.
DE: 2411 Electric fields (2712)
DE: 2415 Equatorial ionosphere
DE: 2427 Ionosphere/atmosphere interactions (0335)
DE: 2768 Plasmasphere
DE: 3369 Thermospheric dynamics (0358)
SC: SPA - Magnetospheric Physics [SM]
MN: 2003 Fall Meeting