HR: 15:20h
AN: SM23D-05    [Abstracts]
TI: Diagnosing and Modeling Distortions of the Subauroral Electric Field
AU: * Goldstein, J
EM: jgoldstein@swri.edu
AF: Southwest Research Institute, 6220 Culebra Road, San Antonio, TX 78238, United States
AB: During geomagnetic activity, coupling between the ring current and sub-auroral ionosphere (via region 2 Birkeland currents) can create ionospheric electric fields--either enhancements such as the subauroral polarization stream (SAPS), or shielding--that have a dramatic effect on the dynamics of the plasmas of the inner magnetosphere. We compare the output of a simple computational model of the plasmasphere to observations, both remote sensing by the Imager for Magnetopause-to-Aurora Global Exploration (IMAGE) satellite and in situ by the geostationary satellites of the Los Alamos National Laboratory (LANL), and show agreement to within 0.2-0.7 RE of the observed plasmapause and/or plume location. These comparisons clearly demonstrate the need to include this region 2 coupling system. Observations during substorms and mild convection enhancements imply that there is a finite speed for the effects of substorms and convection to propagate through the inner magnetosphere, and that this propagation can create turbulent-like flow bursts and undulatory motions at the plasmapause boundary. We show that these effects are a consequence of the finite speed of plasma responding to subauroral convection.
DE: 2712 Electric fields (2411)
DE: 2730 Magnetosphere: inner
DE: 2736 Magnetosphere/ionosphere interactions (2431)
DE: 2778 Ring current
DE: 2788 Magnetic storms and substorms (7954)
SC: SPA-Magnetospheric Physics [SM]
MN: 2007 Joint Assembly