GEM: Development and Application of Magnetospheric Equilibrium Magnetic Field Models

该项目将使用最近开发的地球磁层磁场和压力分布的经验模型作为MHD（磁流体动力学）平衡解算器的输入，计算一套地球内磁层和中磁层的三维平衡解。拟议的研究项目的一个重要组成部分将是平衡求解器的修改，包括各向异性压力的影响，并调查这种修改如何影响所产生的平衡。这项工作将为地球空间环境建模（GEM）计划以及更广泛的空间物理界感兴趣的各种建模和数据分析工作提供有用的投入。计算出的平衡解以及查询和显示结果的相关软件将提供给广大科学界使用。平衡解将根据经验模型中使用的同一组太阳风条件进行分组。模型结果将用于解决几个有趣和重要的科学问题。平衡解将允许在经验等离子体和磁场模型之间进行一致性检查，以确定独立计算的模型与平衡的接近程度。此外，平衡的结果将被用来调查的压力平衡不一致，并探讨等离子体的压力和磁场梯度负责产生的场向电流。在内磁层中，环电流压力是各向异性的。一个悬而未决的问题是，等离子体压力的各向异性发挥重要作用的配置和电动力学的内磁层？使用这些新的均衡模型将有可能回答这个问题和相关的问题。

This project will compute a set of three dimensional equilibrium solutions for Earth's inner and middle magnetosphere using recently developed empirical models of Earth's magnetospheric magnetic field and pressure distributions as inputs to an MHD (magnetohydrodynamic) equilibrium solver. An essential part of the proposed research project will be the modification of the equilibrium solver to include the effects of anisotropic pressure and to investigate how this modification affects the resulting equilibria. This work will create useful inputs for a variety of modeling and data analysis efforts that are of interest to the Geospace Environment Modeling (GEM) program as well as to the wider space physics communities. The computed equilibrium solutions, as well as relevant software to interrogate and display the results, will be made available for use by the scientific community at large. The equilibrium solutions will be binned according to the same set of solar wind conditions as used in the empirical models. The model results will be used to address several interesting and significant scientific questions. The equilibrium solutions will allow for consistency checks between the empirical plasma and magnetic-field models to determine how close the independently calculated models are to equilibrium. In addition, the equilibrium results will be used to investigate the pressure balance inconsistency and to explore the plasma pressure and magnetic-field gradients responsible for the generation of field-aligned currents. In the inner magnetosphere the ring current pressure is known to be anisotropic. An open question is, does plasma pressure anisotropy play an important role in the configuration and electrodynamics of the inner magnetosphere? The use of these new equilibrium models will make it possible to answer this and related questions.