Multi-fluid MHD Simulations of the Plasmasphere

The plasmasphere is an important part of the magnetospheric system. It has a strong effect on the radiation belts, either through modifying ULF wave propagation or through abetting plasma wave activity. In addition, plasmaspheric plumes affect dayside reconnection. We have recently developed an MHD model of the plasmasphere based on the recently developed multi-fluid version of the LFM global MHD code. The plasmasphere within the model consists of a cold hydrogen or cold oxygen component or both. The plasma dynamics is essentially driven by a combination of the corotation and convection electric fields, gravity, and the hot electron pressure ( the electron ambipolar field is shared according to charge density, so predominantly affects the higher density plasmaspheric component). We have used a simple volume refilling model to account for plasma entry from the low latitude ionosphere. We will present results for different amounts of solar wind driving. with an emphasis the dynamically developing structures, which include plumes and other surface waves.