Simulations help us understand the detailed physics. The SPP numerical model simulates a solar storm impacting the magnetosphere and transferring energy through it to Earth's ionosphere. SPP used data from WIND and SOHO for the flow and magnetic field of the January 1997 incoming gust of solar wind. Earth's ionosphere is a lower boundary of the model volume, from which the simulation maps electrical current and velocity through the ionosphere. The black circle represents geosynchronous orbit, with satellite positions indicated.
Earth is magnified by a factor of two for clarity.
The results of the SPP simulations of the January 1997 storm agree well in key details with Earth-orbit satellite data, confirming basic accuracy of the model. The simulation shows bursts of released energy in the ionosphere happening close in time to when such bursts were recorded at near-Earth satellites. The opposed polarities, in theory, allow the magnetic field lines to connect and energy to flow across the connections. The simulations confirm this view, and offer added insight. When the magnetic cloud in front of the gas bubble arrived, it brought with it an abrupt southward shift and an increase in the strength of the solar magnetic field, initiating a prolonged substorm.