Energy Deposition in the Polar Ionospheres: Simulation Studies of Geomagnetic Storm Events

Using the LFM magnetosphere simulation model, we study several geomagnetic disturbance events emphasizing the results for deposition of energy into the polar ionospheres. The major processes for energy deposition are ohmic dissipation of the ionospheric currents driven from the magnetosphere and precipitation of electrons into the auroral regions. The morphology and relative strengths of the Joule dissipation and precipitation during various phases of the events will be discussed. The total rate can be on the order of a terrawatt during intense disturbances. The energy drives winds and causes the atmosphere to swell increasing satellite drag. It also plays a role in the ionospheric storm at lower latitudes. The events presented include the geomagnetic storms of Jan. 10, 1997, May 15, 1997, Sep. 24, 1998, Oct. 18, 1998, and Nov. 20, 2003. Work supported by the NASA LWS program and the NAVO and ARL HPC centers.