GEM: Influence of the Plasma Sheet Density, Temperature, and Local Time Asymmetry on the Ring Current Strength and Peak Location

GEM：等离子体片密度、温度和局部时间不对称性对环电流强度和峰值位置的影响

• 批准号: 0703210
• 负责人: Vania Jordanova
• 金额: $ 10万
• 依托单位: Department of Energy Albuquerque Operations Office
• 依托单位国家: 美国
• 项目类别: Interagency Agreement
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-07-01 至 2010-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0703210&HistoricalAwards=false
• 关键词: GEM; Influence; Plasma; Sheet; Density

Both cold-dense and hot-tenuous plasmas are observed in the near-Earth tail of the magnetosphere. A cold-dense plasma sheet (CDPS) is known to form during intervals of northward interplanetary magnetic field (IMF), and to be of solar wind origin primarily. The hot-tenuous plasma sheet is generally observed for non-northward IMF conditions and can often contain a large contribution from heavier ions (O+ primarily). Both types of populations are a source for the ring current during magnetically active times. Recent observations have also shown the transport of dense plasma from the dawn side of the plasma sheet boundary layer (PSBL) but the properties of this plasma and the potential influence it might have on the formation of the ring current has not been investigated in any detail. This project addresses the topic of plasma sheet properties and transport toward the inner magnetosphere and ring current region of the plasma sheet and PSBL particles in order to assess in a systematic fashion the role of plasma sheet density, temperature and local time asymmetries on the strength of magnetic storms. It aims to answer the following scientific questions: (a) How and where does the plasma sheet and boundary layer plasma enter the inner magnetosphere/ring current region? (b) What are the effects of plasma sheet properties (density, temperature, and local time asymmetries) on proton ring current strength and peak location? The research project will address these questions through a combination of data from key magnetospheric and solar wind science missions (Cluster, Los Alamos geosynchronous instruments, ACE) and simulation results using a kinetic model of the ring current. The research will also contribute to an educational goal. An undergraduate student research program is operated at Los Alamos and it is expected that one or more students will become involved in this project.

在近地磁层尾部观测到冷密等离子体和热稀薄等离子体。 冷密等离子体片（CDPS）是在行星际磁场（IMF）向北变化期间形成的，主要由太阳风引起。 热稀薄等离子体片通常在非北向IMF条件下观察到，并且通常可以包含来自较重离子（主要是O+）的较大贡献。 这两种类型的人口是一个源的环电流在磁活跃的时间。 最近的观测也表明，从黎明侧的等离子体片边界层（PSBL）的致密等离子体的运输，但这种等离子体的性质和潜在的影响，它可能对环电流的形成还没有被调查的任何细节。该项目涉及等离子体片特性和向等离子体片和PSBL粒子的内磁层和环电流区域的传输的主题，以便以系统的方式评估等离子体片密度、温度和当地时间不对称性对磁暴强度的作用。 它旨在回答以下科学问题：（a）等离子体片和边界层等离子体如何以及在何处进入内磁层/环电流区？(b)等离子体片的性质（密度、温度和局部时间不对称性）对质子环电流强度和峰值位置有什么影响？ 该研究项目将综合利用磁层和太阳风科学关键飞行任务（星团、洛斯阿拉莫斯地球同步仪器、ACE）的数据和使用环电流动力学模型的模拟结果来解决这些问题。 这项研究也将有助于实现教育目标。 一个本科生研究计划在洛斯阿拉莫斯运作，预计一个或多个学生将参与这个项目。