CAREER: Collisionless Magnetic Reconnection in the Earth's Magnetosphere

职业：地球磁层中的无碰撞磁重联

• 批准号: 0645271
• 负责人: Michael Shay
• 金额: $ 47万
• 依托单位: University of Delaware
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-03-01 至 2013-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0645271&HistoricalAwards=false
• 关键词: CAREER; Collisionless; Magnetic; Reconnection; Earth

Magnetic reconnection in plasmas is ubiquitous and occurs in laboratory plasma devices, in Earth's magnetosphere, in the heliosphere, on the sun and in astrophysical plasmas. This project will be primarily oriented toward understanding magnetic reconnection in Earth's magnetosphere, but the fundamental, physical understanding of the process will have impacts on many areas of plasma research. The primary questions addressed by this project are: (1) Is magnetic reconnection always bursty and time dependent? Are there situations in which magnetic reconnection can be steady for long periods of time? (2) How does magnetic reconnection energize particles in the Earth's magnetosphere? Does a Fermi process associated with contracting islands play a critical role? What are the signatures expected from this Fermi process, and under what magnetospheric parameters is it active? (3) what are the signatures and properties of reconnection in more realistic geometries applicable to magnetospheric reconnection? How are the signatures and rate of reconnection affected by extremely low density in the magnetospheric lobes and asymmetric inflow conditions at the dayside magnetopause? What is the nature of inherently 3D reconnection around 3D magnetic nulls and separator lines in the dayside magnetosphere? Does Hall physics fundamentally modify the nature of this 3D reconnection? These questions will be studied with a broad range of numerical simulations, using two-fluid, hybrid, and full particle simulations, and implementing new boundary conditions such as open boundaries. The project will also test the effectiveness of a novel multiscale simulation technique called, "Equation Free Projective Integration" (EFPI) which has the potential to have a transformative effect on magnetic reconnection studies, allowing extremely large scale simulations which still include important kinetic physics. The education plan that forms an important part of the project is focused on attracting and retaining students into the field of space physics. To increase student interest, there are outreach programs to high school students and undergraduates, new space physics courses at the undergraduate and graduate level, and better visibility of the University of Delaware (UDEL) space physics program through a unified web site. In order to increase student interest and retention, education and research activities are integrated by including high school, undergraduate, and graduate students in the research program. Weekly group meetings and mentor training will be used to create a "scaffolding of mentoring," whereby older students help to train and mentor younger ones. The participation of underrepresented groups will be promoted by providing the summer high school research experience to a minority student. Finally, the impact of the educational activities will be evaluated by collecting statistics on the education and career choices of students who participate in the UDEL space physics program.

等离子体中的磁重联是普遍存在的，并且发生在实验室等离子体装置中，在地球的磁层中，在日光层中，在太阳上和在天体物理等离子体中。 该项目将主要面向理解地球磁层中的磁重联，但对该过程的基本物理理解将对等离子体研究的许多领域产生影响。本计画所要解决的主要问题是：（1）磁重联是否总是突发性的且与时间有关？是否存在磁场重联可以长时间稳定的情况？(2)磁场重联如何为地球磁层中的粒子提供能量？与收缩岛屿相关的费米过程是否起着关键作用？这个费米过程的特征是什么？在什么样的磁层参数下它是活跃的？(3)在适用于磁层重联的更现实的几何结构中，重联的特征和性质是什么？磁层瓣极低密度和向阳侧磁层顶不对称入流条件如何影响重联的特征和速率？在昼侧磁层的三维磁零和分离线周围，固有的三维重联的性质是什么？霍尔物理学是否从根本上改变了这种3D重连的性质？这些问题将通过广泛的数值模拟进行研究，使用双流体，混合和全粒子模拟，并实施新的边界条件，如开放边界。该项目还将测试一种名为“无方程投影积分”（EFPI）的新型多尺度模拟技术的有效性，该技术有可能对磁重联研究产生变革性影响，从而允许仍然包括重要动力学物理的超大规模模拟。教育计划是该项目的一个重要组成部分，其重点是吸引和留住学生进入空间物理学领域。为了提高学生的兴趣，有面向高中生和大学生的推广方案，在大学生和研究生一级开设了新的空间物理课程，并通过统一的网站提高了特拉华州大学空间物理方案的知名度。为了提高学生的兴趣和保留，教育和研究活动是通过包括高中，本科和研究生在研究计划相结合。每周的小组会议和导师培训将被用来创建一个“指导的脚手架”，让年长的学生帮助培训和指导年轻的学生。将通过向少数民族学生提供暑期高中研究经验，促进代表性不足的群体的参与。最后，将通过收集有关参加UDEL空间物理方案的学生的教育和职业选择的统计数据来评估教育活动的影响。