An adaptive MHD method for global space weather simulations

A 3-D parallel adaptive mesh refinement (AMR) scheme is described for solvi ng the partial-differential equations governing ideal magnetohydrodynamic ( MHD) flows. This new algorithm adopts a cell-centered upwind finite-volume discretization procedure and uses limited solution reconstruction, approxim ate Riemann solvers, and explicit multi-stage time stepping to solve the MH D equations in divergence form, providing a combination of high solution ac curacy and computational robustness across a large range in the plasma beta (beta is the ratio of thermal and magnetic pressures). The data structure naturally lends itself to domain decomposition, thereby enabling efficient and scalable implementations on massively parallel supercomputers. Numerica l results for MHD simulations of magnetospheric plasma flows are described to demonstrate the validity and capabilities of the approach for space weat her applications.