GEM: Impact of Coupling and Feedback Processes in Geospace on Ring Current Dynamics

环电流的动态是产生磁暴的磁变化的主要来源。从对上一个太阳周期的观测中可以清楚地看出，磁暴期间的环电流动态强烈地耦合到地球空间的其他区域。该项目将结合模型和观测，以揭示环电流和这些其他区域之间的联系和反馈。作为拟议工作的一部分，将调查两个影响因素：(1)磁层内部离子沉降区及其与拉伸磁组态的关系；(2)全球锯齿状振荡及其对环电流的影响。本研究选取了一组磁暴进行了详细的对比分析。对于每个重点专题，预期将实现：(1)澄清选定的耦合和反馈机制的性质；(2)增进我们对地球空间这一复杂自然系统的认识；(3)提高我们在全球范围内模拟磁层系统的能力。这项分析将使用密歇根大学开发的两个代码。第一个是环流大气相互作用模型(RAM)，它现在包括了一个自洽的电场模型。第二个是综合空间环境模型(CSEM)，现在包括了磁流体动力学(MHD)模拟程序和动力学赖斯对流模型(RCM)之间的双向耦合，从而提高了内部磁层结果的精度。用于约束、验证和/或驱动模拟的数据集包括：对地球同步轨道的洛斯阿拉莫斯国家实验室(LANL)卫星的粒子观测；国家海洋和大气管理局/极地业务环境卫星(NOAA/POES)的离子降水；国防气象卫星计划(DMSP)卫星的热等离子体观测和极帽潜力；来自成像仪的高能中性原子(ENA)图像，用于磁层顶到极光的全球探测/高能中性原子(IMAGE/HENA)和中能中性原子(MENA)仪器；IMAGE/EUV(极端紫外线成像器)的等离子体层观测；地球静止业务环境卫星(GOES)的磁场观测；和地面磁力仪数据。这项研究将成为研究生博士论文的基础。研究结果将提高对一些悬而未决的磁暴问题的科学理解，研究结果将通过演讲和出版物公布。该项目将增进对造成空间天气影响的一些重要物理过程的科学了解，如全球定位系统误差和卫星异常，从而造福社会。

The dynamics of the ring current is the predominant source of the magnetic variations that produce a magnetic storm. It is clear from observations over the last solar cycle that ring current dynamics during magnetic storms couples strongly to other regions of geospace. This project will combine models and observations to uncover the linkages and feedbacks between the ring current and these other regions. Two influential factors will be investigated as part of the proposed effort:(1) inner magnetospheric ion precipitation zones and their relation to stretched magnetic configurations, and (2) global sawtooth oscillations and their impact on the ring current. A set of magnetic storms has been selected for detailed comparative analysis during this research project. For each focus topic, it is expected to achieve: (1) clarification of the nature of the selected coupling and feedback mechanism; (2) advancement of our knowledge of geospace as a complex natural system; and (3) improvement of our ability to simulate the magnetospheric system on a global scale. The analysis will employ two codes developed at the University of Michigan. The first is the Ring Current Atmosphere Interaction Model (RAM), which now includes a self-consistent electric field model. The second is the Comprehensive Space Environment Model (CSEM), which now includes two-way coupling between the magnetohydrodynamic (MHD) simulation code and the kinetic Rice Convection Model (RCM), improving the accuracy of the inner magnetospheric results. Data sets used to constrain, validate, and/or drive the simulations include: particle observations on the geosynchronous Los Alamos National Laboratory (LANL) satellites; ion precipitation from National Oceanic and Atmospheric Administration/Polar Operational Environmental Satellites (NOAA/POES); thermal plasma observations and polar cap potential from the Defense Meteorological Satellite Program (DMSP) satellites; Energetic Neutral Atom (ENA) images from Imager for Magnetopause-to-Aurora Global Exploration/High Energy Neutral Atom (IMAGE/HENA) and Medium-Energy Neutral Atom (MENA) instruments; plasmasphere observations from IMAGE/EUV (Extreme Ultraviolet Imager); magnetic field observations from Geostationary Operational Environmental Satellites (GOES); and ground-based magnetometer data. The study will be the basis for a graduate student's Ph.D. dissertation. Study results will improve scientific understanding of a number of unanswered magnetic storm questions and the results will be made public through presentations and publications. The project will benefit society by improving scientific understanding of some important physical processes responsible for space weather effects, such as Global Positioning System (GPS) errors and satellite anomalies.