Collaborative Research: SHINE--Exploring Reconnection-Driven Solar Explosive Events in Different Regimes through Modeling and Observation

合作研究：SHINE——通过建模和观测探索不同状态下重新连接驱动的太阳爆炸事件

• 批准号: 2301338
• 负责人: Chuanfei Dong
• 金额: $ 30.89万
• 依托单位: Trustees of Boston University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-07-15 至 2026-06-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2301338&HistoricalAwards=false
• 关键词: Collaborative; Research; SHINE; Exploring; Reconnection

Magnetic reconnection is the mechanism driving explosions on the Sun ranging from nanoflares, ultraviolet bursts, to inter-planetary sized coronal mass ejections. At the core of reconnection is a current sheet where magnetic energy is converted to plasma kinetic energy. This project investigates how plasmoid instabilities lead to reconnection and solar explosions. Magnetic reconnection is a primary driver of space weather and an important fundamental physical process important to space physics, fusion science, and astrophysics. The work supports research of mid-career and early career scientists, including graduate student support. The team will develop lectures to undergraduate students from under-represented groups through NASA’s Heliophysics Summer School.Recent theoretical analyses and numerical simulations predict that reconnection current sheets can spontaneously become unstable to the plasmoid instability. The plasmoid instability fractures the reconnecting current sheet into secondary current sheets, plasmoids, and flux ropes, facilitating the onset of fast reconnection. Depending on the collisionality and global system size in relation to kinetic scales, plasmoid-mediated re- connection can result in a variety of dynamical behaviors. Appropriately capturing critical properties of the dynamical behaviors is crucial for modeling explosive events. This project will develop a deeper understanding of the onset and saturation of plasmoid-mediated fast reconnection in various regimes through a concerted interdisciplinary effort of numerical simulation and solar observation. This is accomplished by: (1) Performing numerical simulations of solar explosive events including large-scale coronal mass ejections in the solar corona and ultraviolet burst events in the lower solar atmosphere. These events cover a broad range of length scales, plasma densities, and temperatures, corresponding to reconnection in different parameter regimes. Simulation results will be compared with observations. (2) Investigating the onset and saturation of fast reconnection in different parameter regimes. To establish a basic understanding of how various models behave in different regimes, the team will conduct 2D and 3D simulations of reconnection in a well-controlled current sheet using resistive magnetohydrodyamic (MHD), Hall MHD, and multi-moment multi-fluid codes to test how microscopic physics descriptions affect the onset and saturation of fast reconnection at large, observable scales.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.

磁重新连接是驱动阳光爆炸的机制，范围从纳米氟，紫外线爆发到行人间尺寸的冠状质量弹出。重新连接的核心是当前纸，其中磁能转化为血浆动能。该项目调查了质量增长的不稳定性如何导致重新连接和太阳爆炸。磁重新连接是太空天气的主要驱动力，也是对空间物理，融合科学和天体物理学重要的重要基本物理过程。这项工作支持研究中期和早期职业科学家的研究，包括研究生支持。该团队将通过NASA的Heliophysics暑期学校开发向来自代表性不足小组的本科生开发讲座。录制理论分析和数值模拟预测，重新连接当前的床单可能对等法不稳定性变得不稳定。等质不稳定性将重新连接到二级电流板，质量和磁通绳，以支撑快速连接的开始。根据相对于动力学尺度的碰撞和全球系统大小，质量介导的重新连接可能会导致各种动态行为。适当捕获动态行为的临界特性对于建模爆炸事件至关重要。该项目将通过一致的数值模拟和太阳观察的协同跨学科的努力来深入了解等离子介导的快速连接的发作和饱和。这是通过：（1）对太阳爆炸事件进行数值模拟，包括太阳电晕中的大规模冠状质量弹出和较低太阳大气中的紫外线爆发事件。这些事件涵盖了广泛的长度尺度，等离子体密度和温度，对应于不同参数制度的重新连接。模拟结果将与观察结果进行比较。 （2）调查不同参数制度中快速重新连接的发作和满意。为了建立对各种模型在不同制度中如何行事的基本理解，团队将使用电阻磁性流体动力（MHD），MHD和多音阶的多音阶多插图在当前表中进行2D和3D模拟，并在当前表中进行重新连接，以测试微观物理学的范围，以观察快速统一的范围。法定使命，并通过评估诚实地认为，使用基金会的智力优点和更广泛的影响审查标准。