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

合作研究：GEM：利用 MHD、混合模拟和观测之间的比较对磁鞘进行全局建模

• 批准号: 1103227
• 负责人: Nojan Omidi
• 金额: $ 11万
• 依托单位: Solana Scientific Inc.
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-06-01 至 2015-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1103227&HistoricalAwards=false
• 关键词: Collaborative; Research; GEM; Global; Modeling

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.

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混合模拟结果进行一系列系统比较。混合模拟将电子视为流体，但将离子视为动态粒子。模拟结果将相互比较，并与THEMIS和Cluster航天器任务的观测结果进行比较。这些比较研究的结果将使我们有可能确定发生在磁鞘及其边界的局部动力学过程在哪里、如何以及在多大程度上改变MHD对其大规模性质和动力学的预测。这项研究将大大提高对局部过程对从太阳风到磁层的质量、能量和动量的大规模传输的影响的理解，并将确定太阳风等离子体状态和国际货币基金组织方向，全球MHD模拟可以可靠地用于此。全球MHD模拟已经成为模拟太阳风如何与地球相互作用的标准方法。磁气圈。这种模型对于预测磁暴等太空天气影响至关重要。然而，宇宙飞船的观测揭示了这种相互作用中的许多影响，这些影响是MHD模拟无法描述的。这个项目将提高我们对何时以及在什么条件下可以依靠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组成部分，涉及一名研究生，他将参与研究的各个方面。