Magnetic Reconnection in Kinetic Turbulent Plasmas

运动湍流等离子体中的磁重联

• 批准号: 2000222
• 负责人: Tak Chu Li
• 金额: $ 54.47万
• 依托单位: Dartmouth College
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-04-01 至 2024-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2000222&HistoricalAwards=false
• 关键词: Magnetic; Reconnection; Kinetic; Turbulent; Plasmas

Understanding the close interconnection between turbulence and magnetic reconnection has been of increasing importance to the broader solar and space physics community. Turbulence is a fundamental physical process of transferring energy from large-scale motions to small kinetic scales, where the turbulence energy is dissipated as plasma heat and particle energization. Magnetic reconnection is a universal physical process that converts magnetic energy to plasma kinetic and thermal energies. Both processes critically influence the dynamics and energetics in systems such as the solar corona, solar wind, and planetary magnetospheres. Magnetic reconnection has been observed in turbulent environments such as the solar wind and the Earth's magneto-sheath. It has been suggested to contribute to energy dissipation of the turbulence and changes in the turbulent cascade by spacecraft observations, simulations and theory. Present knowledge on the physics underlying how magnetic reconnection influences turbulence, and vice versa, is at the very early stages of development. In this regard, the main purpose of this 3-year research project is to improve the physical understanding of the interconnection between magnetic reconnection and turbulence. The main goal of the project is to develop a new technique for identifying and examining reconnection activity using gyro-kinetic simulations of plasma turbulence. The project will support the research of an early-career female scientist, and it will provide research opportunities to undergraduate students at Dartmouth College. These are vital for the education and training of the next generations of scientists, thus contributing to a more diverse STEM workforce in the U.S. The outcome of this research project is expected to yield an improved understanding of the connection between magnetic reconnection and space plasma turbulence, hence leading to more accurate modeling and predictions of the space weather conditions surrounding the Earth. This will contribute to the stability, economy, and technology advancement of the society --- both nationally and globally.This 3-year research project has three science objectives. The first objective is to identify active reconnecting X-points in fully non-linear kinetic turbulence. The second objective is to examine the properties of magnetic reconnection in Alfvenic turbulence. The third objective is to assess the role of reconnection in the heating of magnetized turbulence. The project is directly relevant to the NSF's Solar-Terrestrial Research program, because it would provide important knowledge and an innovative technique for understanding the nature of turbulence and reconnection in space and astrophysical plasmas. This knowledge will be critical for the modeling and predictions of space weather from the surface of the Sun to the Earth and beyond. The new technique will be applicable for analyzing spacecraft data from missions such as MMS, Parker Solar Probe, and Solar Orbiter. The research and EPO agenda of this project supports the Strategic Goals of the AGS Division in discovery, learning, diversity, and interdisciplinary research.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

了解湍流和磁重联之间的密切联系对更广泛的太阳和空间物理界越来越重要。湍流是能量从大尺度运动向小尺度运动转移的基本物理过程，湍流能量以等离子体热量和粒子能量的形式耗散。磁重联是将磁能转化为等离子体动能和热能的普遍物理过程。这两个过程对日冕、太阳风和行星磁层等系统的动力学和能量学都有重要影响。在动荡的环境中，如太阳风和地球的磁鞘中，已经观察到磁重联。宇宙飞船观测、模拟和理论都表明，它有助于湍流的能量耗散和湍流叶栅的变化。目前关于磁重联如何影响湍流，反之亦然的物理学知识，还处于非常早期的发展阶段。在这方面，这个为期3年的研究项目的主要目的是提高对磁重联和湍流之间相互关系的物理认识。该项目的主要目标是开发一种利用等离子体湍流的陀螺动力学模拟来识别和检查重联活动的新技术。该项目将支持一位早期职业女性科学家的研究，并将为达特茅斯学院的本科生提供研究机会。这些对于下一代科学家的教育和培训至关重要，从而有助于美国更加多样化的STEM劳动力。该研究项目的结果有望提高对磁重联和空间等离子体湍流之间联系的理解，从而导致对地球周围空间天气条件的更准确建模和预测。这将有助于国家和全球社会的稳定、经济和技术进步。这个为期三年的研究项目有三个科学目标。第一个目标是确定完全非线性动力学湍流中的主动重连x点。第二个目标是研究阿尔夫尼湍流中磁重联的性质。第三个目标是评估重联在磁化湍流加热中的作用。该项目与美国国家科学基金会的日地研究项目直接相关，因为它将为理解空间和天体物理等离子体中的湍流和重连的本质提供重要的知识和创新的技术。这些知识对于从太阳表面到地球和更远的空间天气的建模和预测至关重要。这项新技术将适用于分析来自MMS、帕克太阳探测器和太阳轨道器等任务的航天器数据。该项目的研究和EPO议程支持AGS部门在发现、学习、多样性和跨学科研究方面的战略目标。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Magnetic Flux Transport Identification of Active Reconnection: MMS Observations in Earth’s Magnetosphere

• DOI: 10.3847/2041-8213/ac5181
• 发表时间: 2022-02
• 期刊: The Astrophysical Journal Letters
• 作者: Y. Qi;Tak Chu Li;C. Russell;R. Ergun;Yingdong Jia;M. Hubbert

The Nonorthogonal X-line in a Small Guide-field Reconnection Event in the Magnetotail

• DOI: 10.3847/1538-4357/acd4ba
• 发表时间: 2023-06
• 期刊: The Astrophysical Journal
• 作者: Y. Qi;R. Ergun;N. Pathak;Tak Chu Li;S. Eriksson;A. Chasapis;S. Schwartz;N. Ahmadi;T. Vo;D. Newman;M. Usanova;F. Wilder;J. Shuster

Identification of Active Magnetic Reconnection Using Magnetic Flux Transport in Plasma Turbulence

• DOI: 10.3847/2041-8213/abea0b
• 发表时间: 2021-03
• 期刊: The Astrophysical Journal Letters
• 作者: Tak Chu Li;Yi‐Hsin Liu;Y. Qi