Collaborative Research: GEM--Transition from Ion-Coupled to Electron-Only Reconnection

合作研究：GEM——从离子耦合到仅电子重联的转变

• 批准号: 2024211
• 负责人: Tai Phan
• 金额: $ 17.1万
• 依托单位: University of California-Berkeley
• 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: 2020-09-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2024211&HistoricalAwards=false
• 关键词: Collaborative; Research; GEM; Transition; Ion

Magnetic reconnection plays a fundamental role in energy transport from the solar wind magnetic fields to the Earth’s magnetic field. This process drives global energy releases in the magnetotail through sub-storms and in the magnetosheath. This project studies how reconnection in the magnetosheath occurs, focusing on the relative contributions from ion-coupled and electron-only reconnection. Understanding of magnetic reconnection is important to national security priorities related to satellites as these events produce space weather affects that can damage or destroy these systems. Additionally, the project will support the next generation of STEM scientists through training of a post-doc and a graduate student and providing internships for at-risk minority high school students.This project is a systematic study of key controlling factors and energy release properties of the transition from ion-coupled to electron-only magnetic reconnection. The primary sub-questions are: (1) What are the factors controlling the transition from ion-coupled to electron-only reconnection? (2) What are the factors controlling heating during reconnection with little or no ion coupling? And (3) Does 3D physics impact the transition from ion-coupled to electron-only reconnection? Kinetic particle-in-cell simulations will be conducted in 2-1/2 and 3 dimensions. The degree of ion coupling, ion exhaust velocities, electron exhaust velocities, and heating in the exhaust will be determined and compared with inflow conditions to determine the key controlling factors and ultimately all the creation of physical models. The simulations and models will be compared with MMS satellite observations of reconnection in the turbulent magnetosheath to both validate the models and find clues to the degree of ion coupling in the observations.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.

磁场重联在太阳风磁场向地球磁场的能量传输中起着重要作用。这一过程通过亚暴驱动磁尾和磁鞘中的全球能量释放。本计画研究磁鞘重联如何发生，着重于离子耦合重联与电子重联的相对贡献。了解磁重联对与卫星有关的国家安全优先事项非常重要，因为这些事件会产生空间天气影响，可能会损坏或摧毁这些系统。此外，该项目还将通过培养一名博士后和一名研究生，以及为处于危险中的少数民族高中生提供实习机会，支持下一代STEM科学家。该项目是对离子耦合磁重联向电子磁重联转变的关键控制因素和能量释放特性的系统研究。主要的子问题是：（1）是什么因素控制了从离子耦合到电子重联的转变？(2)在几乎没有离子耦合的重联过程中，控制加热的因素是什么？以及（3）3D物理学是否影响从离子耦合到仅电子重联的转变？将在2-1/2和3维中进行动力学粒子模拟。将确定离子耦合程度、离子排出速度、电子排出速度和排出物中的加热，并与流入条件进行比较，以确定关键控制因素，并最终创建物理模型。模拟和模型将与MMS卫星观测的湍流磁鞘重连进行比较，以验证模型并找到观测中离子耦合程度的线索。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估来支持。

项目成果

Turbulence-driven magnetic reconnection and the magnetic correlation length: Observations from Magnetospheric Multiscale in Earth's magnetosheath

• DOI: 10.1063/5.0071106
• 发表时间: 2022-01
• 期刊: Physics of Plasmas
• 影响因子: 2.2
• 作者: J. Stawarz;J. Eastwood;T. Phan;I. Gingell;P. Pyakurel;M. Shay;S. Robertson;C. Russell;O. Le Contel

Faster form of electron magnetic reconnection with a finite length X-line

有限长度 X 线的更快形式的电子磁重联

• DOI: 10.1103/physrevlett.127.155101
• 发表时间: 2021
• 期刊: Physical review letters
• 影响因子: 8.6
• 作者: Pyakurel, P. S.;Shay, M. A.;Drake, J. F.;Phan, T. D.;Cassak, P. A.;Verniero, J. L.
• 通讯作者: Verniero, J. L.

On the Short-scale Spatial Variability of Electron Inflows in Electron-only Magnetic Reconnection in the Turbulent Magnetosheath Observed by MMS

MMS观测的湍流磁鞘中纯电子磁重联电子流入的短尺度空间变异性

• DOI: 10.3847/1538-4357/acb6f1
• 发表时间: 2023
• 期刊: The Astrophysical Journal
• 作者: Pyakurel, P. S.;Phan, T. D.;Drake, J. F.;Shay, M. A.;Øieroset, M.;Haggerty, C. C.;Stawarz, J.;Burch, J. L.;Ergun, R. E.;Gershman, D. J.
• 通讯作者: Gershman, D. J.