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

合作研究：GEM--北行行星际磁场期间磁层等离子体的不对称进入和输运

• 批准号: 1003874
• 负责人: Colby Lemon
• 金额: $ 16.5万
• 依托单位: Aerospace Corporation
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-01 至 2014-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1003874&HistoricalAwards=false
• 关键词: Collaborative; Research; GEM; Asymmetric; Entry

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).

该项目将研究当行星际磁场（IMF）朝北时，等离子体从太阳风进入并穿过地球磁层的过程。 在 IMF 向北移动期间，地球等离子体层内的等离子体通常具有两种成分，一种较热，一种相对较冷。 磁层黎明侧的冷成分温度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 PLAsma 传输数值磁层模型 (PLATNUMM) 进行动力学等离子体模拟来研究等离子体的进入和传输机制。 等离子体模拟将使用北向 IMF 条件下的真实磁场和电场模型来完成。 该项目将表征在连接磁层与磁鞘的层中形成的等离子体相空间密度。 模拟结果将与航天器观测到的等离子体进行比较。 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IMF周期通常不是强磁活动周期，但了解磁安静时间的演变很重要，因为它们形成了决定磁干扰期间磁层动态的初始条件。 了解从磁静状态到扰动状态的转变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大学研究项目和独立研发中心（航空航天公司）之间的合作。