GEM: Simulation Studies of Plasma Redistribution in the Ionosphere and Plasma Supply to the Magnetosphere in Geomagnetic Active Periods

该项目的重点是研究大气层上层结构的变化如何导致流入外层空间的等离子体发生变化。在重要的空间天气期间，高层大气中的等离子体循环可能会发生巨大变化，导致极帽上方流动的高密度区域，这可能导致沿磁力线流向外层空间的等离子体外流增加。这些变化可能会影响通过电离层进行的无线电通信，并可能对卫星导航系统得出的位置造成重大误差。研究人员将通过开发一个数值模式来解决这一重要问题。该模型将能够解决流出等离子体如何与这些密度增强相关的问题。成功地对这些相互作用进行建模可能会改进空间天气预报的数值模型。此外，这项调查将支持对一名研究生进行计算机编程和数据分析技术方面的培训。这项研究的一个主要焦点将是对与风暴增强密度(SED)及其可能的对应等离子体层羽流、极帽舌头和斑块相关的等离子体再分布以及与地磁活动期间这种等离子体再分布相关的增强离子流出的模拟研究。拟议研究的目的是将动态流体动力学(DyFK)模型扩展到同时跟踪多个漂移的单个通量管来模拟全球等离子体输运；定量地了解导致等离子体再分布和离子外流的物理过程；提供多个物种的全球离子外流通量的定量测量，以了解电离层等离子体供应对磁层动力学的影响。

This project is focused on investigating how changes in the structure of the upper levels of the atmosphere can lead to changes in the plasma flowing out into the outer space. During periods of significant space weather the circulation of plasma in the upper atmosphere can be dramatically changed, resulting in high density regions flowing over the polar cap that can lead to enhanced outflow of plasma flowing out along magnetic field lines into outer space. These changes can impact radio communications through the ionosphere and may cause significant errors in positions derived from satellite based navigation systems. The investigators will address this important topic through the development of a numerical model. This model will be able to address how the outflow plasma relates to these density enhancements. Success in modeling these interactions could potentially lead to improved numerical models for forecasting space weather. In addition, this investigation will support training of a graduate student in computer programming and data analysis techniques. A major focus of this investigation will be simulation studies of plasma redistribution associated with the storm enhanced density (SED) and its possible counterpart plasmaspheric plume, polar cap tongues and patches, and enhanced ion outflow associated with such plasma redistribution during geomagnetic active times. The objective of the proposed studies is to expand the Dynamic Fluid Kinetic (DyFK) model to simultaneously follow multiple drifting individual flux tubes for simulating global plasma transport; to quantitatively understand physical processes that cause plasma redistribution and ion outflow; to provide quantitative measure of global ion outflow fluxes of multiple species necessary to understand effects of ionospheric plasma supply on the magnetospheric dynamics.