SHINE: Physics-based and Statistical Studies Connecting Surface-field Distributions to the Magnetic Flux Rope Structure in the Corona and Heliosphere

SHINE：基于物理和统计的研究将表面场分布与日冕和日光层的磁通绳结构联系起来

• 批准号: 2228967
• 负责人: Hong Xie
• 金额: $ 50.85万
• 依托单位: Catholic University of America
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-11-01 至 2025-10-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2228967&HistoricalAwards=false
• 关键词: SHINE; Physics; based; Statistical; Studies

Coronal mass ejections (CMEs) from the Sun are the driver of extreme space weather near Earth. This project addresses the Solar, Heliospheric, and Interplanetary Environment (SHINE) goal of understanding the origin and evolution of CMEs through an investigation of magnetic flux ropes. The project is led by scientists from under-represented groups in STEM, who will mentor undergraduate students from underrepresented ethnic minority groups or first-generation college students. The project advances the participation of women in science. Outreach will also be conducted in preparation for the October 2023 and April 2024 solar eclipses.The central goal of this project is to obtain a quantitative understanding of the structure and evolution of magnetic flux ropes from the solar photosphere to the inner heliosphere. The scientific objective of the work is to determine how the reconnected magnetic flux in the solar source region drives the CME flux rope structure in the corona and heliosphere. The proposed objective will be achieved by answering the questions: 1) Do flux ropes exist prior to eruptions, or are they formed during eruptions, or some combination of the two? 2) How magnetic reconnection affect the magnetic properties and kinematics of CME flux ropes? A combination of photospheric and coronal observations combined with flux rope fitting form the basis for geometrical and magnetic characterization of the “flux rope from eruption data” (FRED). The team will determine the direction of the axial magnetic field and magnetic flux rope (MFR) helicity by a combination of magnetogram data and EUV eruptive features (e.g., coronal arcade skews, Fe XII stalks, sigmoids, and magnetic tongues) in solar source regions. Since the flux rope legs are anchored in the photosphere within the EUV core dimming regions in the eruption site, the magnetic flux within the core dimming region corresponds to the flux rope’s axial flux. The reconnected flux within the post eruption arcade corresponds to the poloidal flux of the flux rope. Thus, a MFR is fully defined in the corona and its evolution is tracked under the assumption of self-similar expansion, enabling the prediction of the Bz (out of the ecliptic field) component that encounters Earth. The coronal flux rope structure will be compared against the flux rope in the heliosphere fitted to in-situ observations at various heliocentric distances (Parker Solar Probe, Solar Orbiter, and spacecraft near 1 AU), including self-similar expansion, helicity and the orientation of the coronal and interplanetary flux ropes. The team will use the elliptical flux rope and graduated cylindrical shell techniques for forward modeling of the CME flux ropes. Both the Lepping cylindrical force-free magnetic cloud fitting and Marubashi cylinder and torus fitting are used to derive the MFR structure in CMEs.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.

来自太阳的日冕物质抛射（CME）是地球附近极端空间天气的驱动因素。该项目致力于太阳、日光层和行星际环境（SHINE）的目标，即通过对磁通绳的调查来了解日冕物质抛射的起源和演变。该项目由STEM中代表性不足的群体的科学家领导，他们将指导代表性不足的少数民族群体的本科生或第一代大学生。该项目促进妇女参与科学。还将开展外联活动，为2023年10月和2024年4月的日食做准备，该项目的中心目标是定量了解从太阳光球层到日光层内层的磁通绳的结构和演变。这项工作的科学目标是确定太阳源区重连磁通量如何驱动日冕和日光层中的CME磁绳结构。提出的目标将通过回答以下问题来实现：1）通量绳是在喷发之前存在的，还是在喷发期间形成的，还是两者的某种组合？2)磁场重联如何影响CME磁绳的磁性和运动学？光球和日冕观测与磁绳拟合相结合，构成了“喷发数据磁绳”（FRED）的几何和磁性特征的基础。该团队将通过结合磁图数据和EUV喷发特征（例如，日冕拱廊偏斜，Fe XII柄，S形和磁舌）。由于通量绳腿被锚定在喷发地点的EUV核心变暗区域内的光球中，核心变暗区域内的磁通量对应于通量绳的轴向通量。喷发后拱廊内的重联通量对应于磁绳的极向通量。因此，MFR在日冕中被完全定义，并且在自相似膨胀的假设下跟踪其演变，从而能够预测遇到地球的Bz（黄道场之外）分量。日冕通量绳结构将与日光层中的通量绳进行比较，这些通量绳适合在各种日心距离（帕克太阳探测器、太阳轨道器和1 Au附近的航天器）进行现场观测，包括日冕和行星际通量绳的自相似膨胀、螺旋度和方向。该小组将使用椭圆通量绳和渐变圆柱壳技术对CME通量绳进行正演模拟。Lepping圆柱形无力磁云拟合和Marubashi圆柱和环面拟合都用于推导CME中的MFR结构。该奖项反映了NSF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而被认为值得支持。

项目成果

What Do Halo CMEs Tell Us about Solar Cycle 25?

关于太阳周期 25，Halo 日冕物质抛射告诉我们什么？

• DOI: 10.3847/2041-8213/acdde2
• 发表时间: 2023
• 期刊: The Astrophysical Journal Letters
• 作者: Gopalswamy, Nat;Michalek, Grzegorz;Yashiro, Seiji;Mäkelä, Pertti;Akiyama, Sachiko;Xie, Hong
• 通讯作者: Xie, Hong