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

该项目将研究在行星际磁场向北的间隔期间，太阳风中的等离子体进入和穿过地球磁层的传输情况。 在向北的IMF期间，地球等离子体片内的等离子体通常具有两种成分，一种是热的，另一种是相对冷的。 冷分量在磁层的黎明侧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。 本计画将利用电浆输运数值磁层模式（PLATNUMM）进行电浆进入与输运机制之动力学模拟。 等离子体模拟将使用现实的磁场和电场模型为北IMF条件。 该项目将确定在连接磁层和磁鞘的层中形成的等离子体相空间密度的特征。 模拟结果将与航天器等离子体观测结果进行比较。 此外，该项目还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IMF周期通常不是强磁活动周期，但了解磁静期的演变也很重要，因为它们形成了确定磁扰动时期磁层动态的初始条件。 了解从磁平静到扰动时间的过渡对于我们理解可能影响人类和人类工程系统的空间天气现象非常重要。 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究和开发中心（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).