HR: 1340h
AN: SM13A-0317    [Abstracts]
TI: Nonlinear Modeling of the High-Latitude Geomagnetic Field and dB/dt
AU: * Vassiliadis, D
EM: vassi@electra.gsfc.nasa.gov
AF: ST at NASA/GSFC, Code 612.2 Building 21 Room 265, Greenbelt, MD 20771 United States
AU: Pulkkinen, A
EM: antti.pulkkinen@gsfc.nasa.gov
AF: NRC at NASA/GSFC, Code 612.2, Greenbelt, MD 20771 United States
AU: Klimas, A J
EM: alex.klimas@nasa.gov
AF: NASA/GSFC, Code 612.2, Greenbelt, MD 20771 United States
AB: Two dynamic models, one for the time-dependence of the high-latitude ground magnetic field and one for its time rate of change, dB/dt, are presented. Local models for positions on an annular grid are regressed from magnetic-field measurements taken at the IMAGE meridional array. The nonlinear response at high activity is represented by local-linear models which are driven by real-time solar wind/IMF datastreams. We report the field response during isolated substorms and the great storms of October-November 2003. In those events the model prediction error for the field and its time rate of change is measured as a function of geomagnetic coordinates and activity level. Based on the predicted dB/dt we estimate the GIC disturbance level and compare with GIC measurements at the Finnish power grid.
DE: 2784 Solar wind/magnetosphere interactions
DE: 2788 Magnetic storms and substorms (7954)
DE: 2790 Substorms
DE: 7904 Geomagnetically induced currents
DE: 7924 Forecasting (2722)
SC: SPA-Magnetospheric Physics [SM]
MN: Fall Meeting 2005