Collaborative Research: GEM--Asymmetric Entry and Transport of Magnetospheric Plasma During Periods of Northward Interplanetary Magnetic Field

该项目将研究当行星际磁场（IMF）向北时，太阳风中的等离子体进入并穿过地球磁层的过程。在向北的国际货币基金组织期间，地球等离子体层内的等离子体通常具有两种成分，一种是热的，一种是相对冷的。磁层黎明侧的冷成分比黄昏侧的温度稍高，这表明等离子体进入磁层的机制是不对称的。该项目将使用等离子体输运数值磁层模型（PLATNUMM）进行动力学等离子体模拟，研究等离子体的进入和输运机制。等离子体模拟将使用现实的磁场和电场模型进行北IMF条件。该项目将描述连接磁层和磁鞘层的等离子体相空间密度。模拟结果将与宇宙飞船对等离子体的观测结果进行比较。此外，该项目将模拟等离子体片内的等离子体循环，以了解在大尺度特征中观察到的不对称性。虽然向北的国际货币基金组织时期通常不是强磁活动时期，但了解磁平静时期的演变是很重要的，因为它们形成了决定磁扰动时期磁层动力学的初始条件。了解从磁场安静到扰动时期的转变对我们理解可能影响人类和人类工程系统的太空天气现象非常重要。大部分研究将由一名女研究生进行，该项目涉及加州大学洛杉矶分校的一个大学研究项目和一个独立的研发中心（航空航天公司）之间的合作。

This project will investigate the transport of plasma from the solar wind into and through Earth's magnetosphere during intervals when the interplanetary magnetic field (IMF) has a northward orientation. During periods of northward IMF the plasma within Earth's plasma sheet often is characterized by having two components, one hot and one relatively cold. The cold component has a somewhat higher temperature on the dawn flank of the magnetosphere than on the dusk side and this suggests that the mechanism by which plasma enters the magnetosphere is not symmetric. This project will use kinetic plasma simulations with the PLAsma Transport Numerical Magnetosphere Model (PLATNUMM) to investigate the plasma entry and transport mechanism. The plasma simulations will be done using realistic magnetic and electric field models for northward IMF conditions. The project will characterize the plasma phase space densities that develop in the layer connecting the magnetosphere with the magnetosheath. The results of the simulation will be compared with observations of the plasma from spacecraft. In addition, the project will simulate the plasma circulation within the plasma sheet in order to understand the asymmetries observed in the large-scale features.Although periods of northward IMF are typically not periods of strong magnetic activity it is important to understand the evolution of the magnetically quiet times because they form the initial conditions that determine the dynamics of the magnetosphere during magnetically disturbed times. Understanding the transition from magnetically quiet to disturbed times is important for our understanding of space weather phenomena that can impact humans and human engineered systems. Much of the research will be carried out by a female graduate student and the project involves a collaboration between a university research program at UCLA and an independent research and development center (Aerospace Corporation).