HR: 0800h
AN: SA21C-0369    [Abstracts]
TI: Modeling ionospheric electric fields and currents with combined magnetospheric and ionospheric sources
AU: * Richmond, A D
EM: richmond@ucar.edu
AF: NCAR High Altitude Observatory, P.O. Box 3000, Boulder, CO 80307 United States
AU: Maute, A
EM: maute@ucar.edu
AF: NCAR High Altitude Observatory, P.O. Box 3000, Boulder, CO 80307 United States
AB: We describe a model of ionospheric electrodynamics that forms part of the National Center for Atmospheric Research Thermosphere-Ionosphere-Electrodynamics General-Circulation Model (NCAR TIE-GCM), and use it to examine some properties of ionosphere-magnetosphere electric fields and currents. Electrical coupling with the magnetosphere is represented by a combination of three possible effects: (1) a specified net field-aligned current into or out of conjugate points of both the northern and southern ionospheres; (2) a high-latitude reference electric field with an accompanying reference conductance that determines how strongly the actual electric field is pulled toward the reference field; and (3) region-2 field-aligned currents computed from the divergence of field-perpendicular magnetospheric currents which are related to the electric field through equivalent magnetospheric conductances. In addition, the ionospheric wind dynamo contributes to the electric fields and currents at all latitudes. We illustrate the influences of the different sources on electric fields and currents at high and low latitudes with a TIE-GCM simulation for solstice conditions, when the field-aligned currents are asymmetric between the two hemispheres.
DE: 2409 Current systems (2708)
DE: 2411 Electric fields (2712)
DE: 2431 Ionosphere/magnetosphere interactions (2736)
DE: 2708 Current systems (2409)
DE: 2736 Magnetosphere/ionosphere interactions
SC: SPA-Aeronomy [SA]
MN: 2004 AGU Fall Meeting