3-D global hybrid simulations of the magnetosphere dynamics

A 3-D global hybrid simulation code with domain including both the dayside and nightside magnetosphere has been developed to study the dynamics of the magnetosphere associated with substorms. The inner boundary condition at r = 3.5RE is determined by mapping the parallel currents and electric field to the ionosphere. A run for the case with a southern IMF is studied. It is found that magnetic reconnection in the magnetotail plasma sheet leads to 3-D flux ropes around the equatorial region. Correspondingly, ions are injected Earthward toward the inner magnetosphere which is associated with bursty bulk flow (BBF) and dipolarization front (DF). Proton particle distributions reveal multiple ion populations/beams in the plasma sheet at various distances in the tail. The ion distributions are in general anisotropic, and non-Maxwellian distributions are shown in the energy spectrum. Magnetotail shows strong dawn-dusk asymmetry which is caused by Hall electric field drift. So the magnetotail reconnection tends to happen on dusk side. Interchange instability is also observed at dawn side near Earth region.