Collaborative Research: GEM: System Study of the Plasmasphere in Solar Wind-Magnetosphere Coupling

地球空间环境建模（GEM）项目是一个基础广泛、由社区发起的研究项目，研究地球磁层的物理特性以及磁层与大气和太阳风的耦合。GEM的工作是通过一系列运动和焦点小组来解决具体问题，从而构建具有预测能力的全球地球空间环流模型（GGCM）。该项目将为这一目标提供重要的结果，有助于理解磁层等离子体分布和密度在确定太阳风-磁层耦合效率方面的作用。此外，该项目支持两名早期空间物理科学家独立研究事业的发展。它还将为加州大学伯克利分校和密歇根大学安娜堡分校的本科生提供教育机会。该项目的最终目标是开发和验证一个全球模型，该模型能够精确再现等离子体层动力学，以及等离子体层对日面重联率和整体磁层顶动力学的自一致影响。利用现有的最先进的模型，将开发两种不同的方法，将等离子层纳入全球MHD模型，并使用来自THEMIS、范艾伦带探测器和LANL卫星任务的多点航天器测量进行评估。然后，最好的、经过充分验证的方法将被用于模拟三种不同的风暴事件，并以各种方式测量包括和不包括等离子层的重联率。

The Geospace Environment Modeling (GEM) Program is a broad-based, community-initiated research program on the physics of the Earth's magnetosphere and the coupling of the magnetosphere to the atmosphere and to the solar wind. The work of GEM is accomplished in a series of campaigns and focus groups that solve specific problems leading to the construction of a global Geospace General Circulation Model (GGCM) with predictive capability. This project will contribute essential results to this goal pertaining to understanding the role of the magnetospheric plasma distribution and density in determining the efficiency of the solar wind-magnetosphere coupling. In addition, the project supports the development of independent research careers for two early-career space physics scientist. It also will offer educational opportunities for undergraduate students both at University of California Berkeley and University of Michigan Ann Arbor. The ultimate goal of this project is the development and validation of a global model capable of reproducing accurate plasmasphere dynamics and the self-consistent effects of the plasmasphere on the dayside reconnection rate and overall magnetopause dynamics. Utilizing existing state-of-the-art models, two different approaches for incorporating the plasmasphere in a global MHD model will be developed and evaluated using multipoint spacecraft measurements from the THEMIS, Van Allen Belts Probes, and LANL satellites missions. The best, and fully validated, approach will then be used to model three different storm events and measure the reconnection rates in a variety of ways with and without inclusion of the plasmasphere.