A New Global Semi-Kinetic Simulation Model of Coupled Inner Magnetosphere-Ionosphere

We developed a new semi-kinetic simulation model to study global plasma transportation in the coupled inner magnetosphere-ionosphere system. In this model, we adapt geodesic icosahedral grids with nearly square faces on spherical surfaces, which gives rise to quasi-uniform grids system without singularity points at the northern and southern poles. Ions are treated as simulation particles and electrons are treated as a fluid. Equations of motion of up to 10^9 simulation particles are solved subjected to electric field, magnetic field, and gravitational force. Electric field is self-consistently solved from generalized Ohm's law. Below the lower boundary of the semi-kinetic model, we employ GITM model to provide the bottom boundary conditions; meanwhile, the calculated moments (density, velocity, and temperature) resulted from particle distribution functions are used to provide upper boundary condition for the GITM.. In this presentation, we describe methods used to construct icosahedral grids and cutting-edge techniques of organization grids and simulation particles in memory and fast identification of particle locations in icosahedral mash cells. We also discuss potential application of the model in studying global redistribution of plasma densities in the inner magnetosphere-ionosphere during magnetic activities and the ultimate ionospheric ion outflow.