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: 1954503
• 负责人: Qiang Hu
• 金额: $ 29.84万
• 依托单位: University of Alabama in Huntsville
• 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 2025-03-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1954503&HistoricalAwards=false
• 关键词: Collaborative; Research; Dynamic; Non; Force; 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.

太阳耀斑和冠状质量弹出（CME）对应于冠状磁场的突然重新配置。 众所周知，太阳磁场的拓扑和演变是确定为太阳喷发提供能量存储和启动的因素。 尽管已知磁性稳定性（例如圆环和扭结）与太阳耀斑的发作有关，但尚不清楚耀斑引发与非福利频率和某些光电磁场的某些不断发展的结构有关。 其中包括小规模的磁重连接，也通过前闪光灯亮丽表示。 在最近几年中，使用了大熊太阳能天文台（BBSO）的1.6 m Goode太阳能望远镜（GST）的最先进观测值，以及近年来，近年来，近年来，近年来，Sun Atred的冠状磁场超滤光度，加上了高级磁性水力学（MHD）建模工具和分析技术。 这个为期三年的合作项目的主要目的是扩大有关太阳能弹性期间发生的磁性释放过程的现有知识的前沿。 该项目的研究结果有望为未来高分辨率太阳耀斑研究的科学准备以及DKIST的数据分析工具的开发。 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：喷发前太阳大气的非无力特性，以及小规模磁重复连接在太阳耀斑启动中的作用。 研究耀斑相关的磁场演化有望揭示太阳喷发的潜在物理机制，这些物理机制是太阳天气的物理驱动因素。 此外，这个协作项目具有强大的教育和学生培训部分。 它将支持两名博士后研究人员：一个在NJIT，另一个在UAH，另一名在UAH的博士生。 NJIT将在培训研究生和年轻研究人员中扮演关键角色，成为DKIST的未来用户。 数据分析和成像处理工具可以由许多其他科学和工程领域使用。 NJIT和UAH的学生人数都非常多。 该项目将推进两个机构中代表性不足的学生的教育。该团队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变进行基本的物理理解。 这项研究将结合来自HMI，HINODE的光谱极光的矢量磁图以及来自GST的高分辨率高分辨率矢量磁图。 高分辨率观察是必要的，因为它们可以揭示耀斑位点周围动态磁场结构的细节。 在这些高分辨率观察结果下，光球附近的太阳活跃区域（ARS）的非无力特性变得更加突出。 项目团队将分析三个互补的现有矢量磁牌数据。 SDO/HMI提供了大约2至12分钟的节奏的全盘矢量磁图，这使大规模磁场结构和进化能够研究。 BBSO/GST在0.1“ 0.1”和30秒的时间节奏方面实现了高分辨率，因此提供了一个独特的数据源，用于研究耀斑核心区域的详细细节。hinode/sp数据以低节奏获得，但它们自2006年以来提供了较丰富的Flares，并提供了质量的质量检查，并提供了更新的gast Magnetsmags（FROVER）。基于HMI，HINODE和GST数据的外推将其与更成熟的非线力场（NLFFF）建模结果进行比较。事件。使用观测，外推和MHD模拟，项目团队将确定非努力和不断发展的磁场在耀斑启动和前体亮度中的作用。 作为建模验证的一部分，将将观察到的耀斑色带运动和轻便后磁重组与MHD建模结果进行比较。 该项目的研究和EPO议程支持了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NSF的法定任务，并认为值得通过基金会的知识分子优点和更广泛影响的评估标准通过评估来获得支持。