Collaborative Research: Dynamic and Non-Force-Free Properties of Solar Active Regions and Subsequent Initiation of Flares

合作研究：太阳活动区域的动态和非无力特性以及随后耀斑的引发

• 批准号: 1954737
• 负责人: Haimin Wang
• 金额: $ 38.48万
• 依托单位: New Jersey Institute of Technology
• 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=1954737&HistoricalAwards=false
• 关键词: Collaborative; Research; Dynamic; Non; Force

Solar flares and coronal mass ejections (CMEs) correspond to a sudden, major reconfiguration of the coronal magnetic field. It has been well known that the topology and evolution of Sun's magnetic fields are determining factors in providing energy storage and initiation for solar eruptions. Although magnetic instabilities, such as torus and kink, are known to be related to onset of solar flares, it is still unclear how flare initiation is related to non-force-freeness and certain evolving structures of photospheric magnetic fields. These include small-scale magnetic reconnections, which are also signified by pre-flare brightenings. The use of state-of-the-art observations from the 1.6-m Goode Solar Telescope (GST) at the Big Bear Solar Observatory (BBSO), plus advanced magnetohydrodynamical (MHD) modeling tools and analysis techniques for the extrapolation of coronal magnetic field of the Sun matured significantly in recent years. The main purpose of this 3-year collaborative project is to expand the frontiers of existing knowledge on the magnetic energy release process occurring during solar flares. The research outcome of this project is expected to contribute to the scientific preparation for the future high-resolution solar flare studies, as well as the development of data analysis tools for the DKIST. The research project addresses some key science questions related to solar flares, namely: the non-force-free properties of solar atmosphere prior to eruptions, and the role of small-scale magnetic reconnections in the initiation of solar flares. Studying flare-associated magnetic field evolution promises to reveal the underlying physical mechanism of solar eruptions, which are the physical drivers of space weather at the Sun. Furthermore, this collaborative project has a strong educational and student training component. It will support two post-doctoral researchers: one at the NJIT and the other at the UAH, and a PhD student at the UAH. The NJIT will play a key role in training graduate students and young researchers to be the future users of the DKIST. The data analysis and imaging processing tools can be used by many other areas of science and engineering. Both the NJIT and UAH have a very diverse student population. The project will advance the education of underrepresented students in both institutions.The team will conduct a comprehensive study of solar flares in order to achieve a fundamental physical understanding of the aforementioned flare-related magnetic field evolution. The study will combine vector magnetograms from HMI, the spectropolarimeter of Hinode, and the high-resolution, high-cadence vector magnetograms from the GST. The high-resolution observations are necessary as they can reveal the fine details of dynamic magnetic field structures around flaring sites. The non-force-free properties of Sun's Active Regions (ARs) near the photosphere become even more prominent under these high-resolution observations. Three complementary sets of existing vector magnetograph data will be analyzed by the project teams. The SDO/HMI provides full-disk vector magnetograms with a cadence of about 2 to 12 minutes, which enable the study of the large-scale magnetic field structure and evolution. The BBSO/GST achieves a high resolution in the order of 0.1" and a temporal cadence of 30 seconds, thus providing a unique data source for studying the flare core regions in great details. The Hinode/SP data are obtained at a low cadence, but they cover a rich archive of flares since 2006 and provide a quality check for more recent GST magnetograms. The project teams will carry out Non-Force-Free Field (NFFF) extrapolations based on combined HMI, Hinode, and GST data and compare them with the more mature Non-Linear Force-Free Field (NLFFF) modeling results. The NFFF extrapolation will reveal the Lorentz force distribution and evolution of flare productive ARs. Using extrapolated coronal fields as initial conditions from extrapolations, the teams will apply 3D data-constraint and data-driven MHD modeling to select events. Using observations, extrapolation, and MHD simulations, the project teams will determine the role of non-force-freeness and evolving magnetic fields in flare initiation and precursor brightening. As part of the modeling validation, observed flare ribbon motion and the post-flare magnetic restructuring will be compared with the MHD modeling results. 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.

太阳耀斑和日冕物质抛射（cme）对应于日冕磁场突然的重大重构。众所周知，太阳磁场的拓扑结构和演化是提供能量储存和引发太阳爆发的决定性因素。虽然已知磁不稳定性（如环面和扭结）与太阳耀斑的发生有关，但尚不清楚耀斑的发生与非力自由和光球磁场的某些演化结构之间的关系。这包括小规模的磁重联，也可以通过耀斑前的变亮来表示。近年来，利用位于大熊太阳天文台（BBSO）的1.6米古德太阳望远镜（GST）的最先进的观测数据，加上先进的磁流体动力学（MHD）建模工具和分析技术，对太阳日冕磁场进行外推的技术已经显著成熟。这个为期3年的合作项目的主要目的是扩大现有知识的前沿，在太阳耀斑期间发生的磁能释放过程。该项目的研究成果有望为未来高分辨率太阳耀斑研究的科学准备以及DKIST数据分析工具的开发做出贡献。该研究项目解决了与太阳耀斑有关的一些关键科学问题，即：爆发前太阳大气的非无力特性，以及小规模磁重联在太阳耀斑形成中的作用。研究与耀斑相关的磁场演化有望揭示太阳爆发的潜在物理机制，这是太阳空间天气的物理驱动因素。此外，这个合作项目有很强的教育和学生培训成分。它将支持两名博士后研究人员：一名在新泽西理工大学，另一名在亚利桑那大学，以及一名在亚利桑那大学的博士生。NJIT将在培养研究生和年轻研究人员成为DKIST的未来用户方面发挥关键作用。数据分析和成像处理工具可用于科学和工程的许多其他领域。NJIT和UAH的学生群体都非常多样化。该项目将促进两所院校中代表性不足的学生的教育。该小组将对太阳耀斑进行全面的研究，以便对上述耀斑相关的磁场演化有一个基本的物理理解。该研究将结合HMI的矢量磁图、Hinode的偏振光谱仪和GST的高分辨率、高节奏矢量磁图。高分辨率的观测是必要的，因为它们可以揭示燃烧点周围动态磁场结构的精细细节。在这些高分辨率观测下，靠近光球层的太阳活动区（ARs）的非无力特性变得更加突出。项目组将对现有的三组互补的矢量磁图数据进行分析。SDO/HMI提供全磁盘矢量磁图，其节奏约为2 ~ 12分钟，可用于研究大尺度磁场结构和演化。BBSO/GST达到了0.1英寸的高分辨率和30秒的时间节奏，从而为详细研究耀斑核心区域提供了独特的数据源。Hinode/SP数据是以低节奏获得的，但它们涵盖了自2006年以来丰富的耀斑档案，并为最近的GST磁图提供了质量检查。项目团队将基于HMI、Hinode和GST数据进行Non-Force-Free Field （NFFF）外推，并将其与更成熟的非线性Force-Free Field （NLFFF）建模结果进行比较。NFFF外推将揭示产生耀斑的ar的洛伦兹力分布和演化。利用外推的日冕场作为初始条件，团队将应用3D数据约束和数据驱动的MHD建模来选择事件。通过观察、外推和MHD模拟，项目团队将确定非力自由和演化磁场在耀斑起始和前体增亮中的作用。作为模型验证的一部分，观测到的耀斑带运动和耀斑后的磁重构将与MHD模型结果进行比较。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

Multi-passband Observations of a Solar Flare over the He i 10830 Å line

He i 10830 × 线上太阳耀斑的多通带观测

• DOI: 10.3847/2041-8213/ac447c
• 发表时间: 2022
• 期刊: The Astrophysical Journal Letters
• 作者: Xu, Yan;Yang, Xu;Kerr, Graham S.;Polito, Vanessa;Sadykov, Viacheslav M.;Jing, Ju;Cao, Wenda;Wang, Haimin
• 通讯作者: Wang, Haimin

High-resolution Observations of Small-scale Flux Emergence by GST

• DOI: 10.3847/1538-4357/aba696
• 发表时间: 2020-09
• 期刊: The Astrophysical Journal
• 作者: Jiasheng Wang;Chang Liu;W. Cao;Haimin Wang

Coronal Magnetic Field Measurements along a Partially Erupting Filament in a Solar Flare

• DOI: 10.3847/1538-4357/ac2f99
• 发表时间: 2021-10
• 期刊: The Astrophysical Journal
• 作者: Yuqian Wei;B. Chen 陈;Sijie 思捷 Yu 余;Haimin Wang;J. Jing;D. Gary

A Data-constrained Magnetohydrodynamic Simulation of the X1.0 Solar Flare of 2021 October 28

• DOI: 10.3847/1538-4357/ac9df4
• 发表时间: 2022-10
• 期刊: The Astrophysical Journal
• 作者: D. Yamasaki;S. Inoue;Y. Bamba;Jeongwoo Lee;Haimin Wang

Comparison of the Hall Magnetohydrodynamics and Magnetohydrodynamics Evolution of a Flaring Solar Active Region

• DOI: 10.3847/1538-4357/ac3bce
• 发表时间: 2021-12
• 期刊: The Astrophysical Journal
• 作者: K. Bora;R. Bhattacharyya;A. Prasad;B. Joshi;Q. Hu