Collaborative Research: GEM: Global Modeling of the Magnetosheath Using Comparisons Between MHD, Hybrid Simulations and Observations

该项目将对全球三维磁流体动力学（MHD）模拟结果与地球磁鞘和磁层顶的混合模拟结果进行一系列系统的比较。 混合模拟将电子视为流体，但将离子视为动力学粒子。 这些模拟将相互比较，并与THEMIS和Cluster航天器飞行任务的观测结果进行比较。这些比较研究的结果将有可能确定在磁鞘和其边界发生的局部动力学过程在哪里，如何，以及在何种程度上改变其大规模的性能和动力学的MHD预测。这项研究将大大提高当地的过程对大规模运输的质量，能量和动量从太阳风的磁层的影响的理解，并将确定太阳风等离子体制度和IMF的方向，全球MHD模拟可以使用reliably.Global MHD模拟一直是标准的方法来模拟太阳风如何与地球相互作用？的磁层。这种建模对于预测磁暴等空间天气效应至关重要。 然而，航天器的观测揭示了这种相互作用中的许多效应，这些效应无法用MHD模拟来描述。该项目将提高我们对何时以及在何种条件下可以依靠MHD模拟进行空间天气预报的理解。该项目还将包括一个教育部分，让一名研究生参与研究的各个方面。

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.