Modeling The Storm Time Electrodynamics

A model that electrodynamically couples inner magnetosphere, ionosphere, plasmasphere, thermosphere, and electrodynamics has been developed and is used to separate sources of the storm time electric fields between the magnetospheric, ionospheric, and themiospheric processes and to investigate their nonlinear interactions. The two sources of the electric-field disturbances, prompt penetration (PP) and disturbance dynamo (DD), have been identified in the coupled model results. Furthermore, the results suggest that the sources of variability in storm time electric fields are associated with the nonlinear interaction between the PP and DD, such that the response depends on the preconditioning of the coupled system. The preconditioning in this study is caused by the fact that the magnetosphere, ionosphere, and thermosphere respond to external forcing as a coupled system. The results clearly demonstrate the need for a fully coupled model of magnetosphere-ionosphere-thermosphere, in order to determine the preconditioning effect.