This project will perform of a series of systematic comparisons between the results of global three-dimensional magnetohydrodynamic (MHD) simulations and hybrid simulations of Earth's magnetosheath and magnetopause. The hybrid simulations will treat the electrons as a fluid but will treat the ions as kinetic particles. The simulations will be compared with each other as well as with observations from the THEMIS and Cluster spacecraft missions. Results of these comparative studies will make it possible to determine where, how, and to which extent local kinetic processes occurring in the magnetosheath and at its boundaries alter the MHD predictions of its large-scale properties and dynamics. The research will considerably improve the understanding of the effects of local processes on the large-scale transport of mass, energy, and momentum from the solar wind to the magnetosphere and will ascertain the solar wind plasma regimes and IMF orientations for which global MHD simulations can be used reliably.
Global MHD simulations have been the standard approach to modeling how the solar wind interacts with Earth?s magnetosphere. Such modeling is crucial to predicting space weather effects such as magnetic storms. Spacecraft observations, however, have revealed a number of effects in that interaction that cannot be described by MHD simulations. This project will improve our understanding of when and under what conditions MHD simulations can be relied on for space weather forecasting. The project will also include an educational component by involving a graduate student who will participate in every aspect of the research.
