MHD simulation of magnetospheric transport at the mesoscale

Abstract

Global MHD simulations of the magnetosphere reveal unsteady vortical plasma flows at the mesoscale, similar in appearance to fluid turbulence at moderate Reynolds numbers, in the magnetotail under a variety of solar- wind conditions and interplanetary magnetic field (IMF) orientations. Such results are not unexpected in view of satellite data for magnetotail plasma- flow properties and the chaotic nature of the model MHD equations. Simulations generated with the Integrated Space Weather Prediction Model that are driven by either steady-state or highly variable solar-wind and IMF conditions suggest mesoscale vortical flows to be pervasive and robust features of magnetotail dynamics. Intermittent surges in simulated plasma flows are suggestive of bursty bulk flows. Autocorrelation functions for fluctuating properties in the simulated plasma sheet compare favorably to corresponding statistical reductions of satellite data.