Why Do Active Regions Erupt? Modeling of Active Region from Pre-Eruptive to Eruptive Processes

为什么活跃区域会爆发？

• 批准号: 1650854
• 负责人: Qiang Hu
• 金额: $ 38.59万
• 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: 2017
• 资助国家: 美国
• 起止时间: 2017-08-01 至 2021-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1650854&HistoricalAwards=false
• 关键词: Why; Do; Active; Regions; Erupt

Solar eruptions have significant impact on the near-Earth environment due to the enhanced flux of energetic particles bombarding the Earth and the embedded magnetic structures impacting the Earth's magnetosphere. This has serious consequences for our technological assets both in space and on the ground, including interruption of tele-communication, compromising the safety of astronauts, and damaging satellites and electric power grids. Therefore, focused investigations of solar eruptions and the associated magnetic field evolution of the solar corona have the potential to reveal the underlying physical mechanism(s) of the drivers of space weather at the Sun. This 3-year project is aimed at investigating the physical origins of solar eruptions at the Sun by means of data-driven, three-dimensional (3-D) numerical simulations. The project also has a strong educational component as it provides partial support for a Ph.D. student and a junior scientist at the University of Alabama in Huntsville. Thus, the research and EPO agenda of this project supports the Strategic Goals of the AGS Division in discovery, learning, diversity, and interdisciplinary research.This 3-year project is aimed at answering some of the fundamental questions concerning the physical origin and evolution of solar eruptions, which will expand the frontier of existing knowledge on the energy release during solar flares and Coronal Mass Ejections (CMEs) on the Sun and the associated reconfiguration of the solar corona. The underlying research objectives are: (i) understanding the fundamental active region (AR) eruptive physics; and, (ii) providing a practical tool as an initiation model for the development of a physics-based data-driven space weather prediction code. The research plan is to use the MHD-DARE model developed by the project team, together with observational data from the HMI and AIA instruments onboard the Solar Dynamics Observatory (SDO), to address the following science questions: (i) what are the basic characteristics of magnetic field configuration before a solar eruption?; (ii) how do photospheric surface motions, including shear, convergence and flux cancellation bring the initial emerged fields to such an unstable configuration?; (iii) what are the specific roles played by magnetic flux rope and magnetic reconnection in triggering solar eruptions?; (iv) can we understand the complexity of various flare/eruption process from topology and evolution of the magnetic field?; and, (v) how do solar eruptions leave imprints on the photospheric fields? These aspects of the AR development will be connected to the evolution of the coronal field long before and during a solar eruption, for which the project team will use the MHD-DARE model to carry out numerical simulations driven by the time-dependent vector magnetograms. Then, the simulation results will be analyzed to yield the evolution of the magnetic topology, electric currents, plasma flows, and Lorentz force to determine the primary triggering mechanisms of the solar eruption, and they will be compared with relevant solar observations. In addition, the project team plans to further improve the current model by including a realistic energy equation and a plasma configuration directly from the photosphere into the solar corona.

由于能量颗粒轰炸地球和影响地球磁层的嵌入式磁性结构，太阳喷发对近地环境具有重大影响。 这对我们在太空和地面上的技术资产都有严重的影响，包括远程通信的中断，损害宇航员的安全以及破坏性的卫星和电力电网。 因此，对太阳喷发的重点研究和太阳电晕的相关磁场演变具有揭示太阳天气驱动因素的潜在物理机制。 这个为期三年的项目旨在通过数据驱动的三维（3-D）数值模拟来研究太阳在太阳处的物理起源。 该项目还具有强大的教育组成部分，因为它为博士提供了部分支持。亨茨维尔阿拉巴马大学的学生和初级科学家。 因此，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。这项为期3年的项目旨在回答有关有关物理起源和进化的一些基本问题太阳爆发将扩大太阳耀斑和冠状质量弹出（CME）的现有知识的前沿，以及太阳电晕的相关重新配置。 基本的研究目标是：（i）了解基本活性区域（AR）喷发物理学； （ii）提供一个实用工具作为开发基于物理数据驱动的太空天气预测代码的启动模型。 该研究计划是使用项目团队开发的MHD Ware模型，以及来自HMI和AIA Instermuments在Solar Dynamerics天文台（SDO）上的观察数据，以解决以下科学问题：（i）什么是基本的。太阳喷发之前的磁场配置的特征？ （ii）光电表面运动（包括剪切，收敛和通量取消）如何使初始出现的磁场达到如此不稳定的配置？ （iii）磁通绳和磁重新连接在触发太阳喷发中扮演的特定作用是什么？ （iv）我们能否了解磁场拓扑和演变的各种耀斑/喷发过程的复杂性？ （v）太阳喷发如何在光电场上留下烙印？ AR开发的这些方面将在太阳喷发前后很久以前与冠状场的演变有关，为此，项目团队将使用MHD-DARE模型进行由时间依赖性矢量磁力图驱动的数值模拟。 然后，将分析仿真结果，以产生磁拓扑，电流，等离子体流和洛伦兹力的演变，以确定太阳喷发的主要触发机制，并将它们与相关的太阳观测结果进行比较。 此外，项目团队计划通过将现实的能量方程式和等离子体配置直接从Photosphere到太阳能电晕，进一步改善当前模型。

项目成果

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

Magnetohydrodynamic Simulation of Magnetic Null-point Reconnections and Coronal Dimmings during the X2.1 Flare in NOAA AR 11283

• DOI: 10.3847/1538-4357/abb8d2
• 发表时间: 2020-09
• 期刊: The Astrophysical Journal
• 作者: A. Prasad;K. Dissauer;Q. Hu;R. Bhattacharyya;A. Veronig;Sanjay Kumar;B. Joshi

Validation and Interpretation of a Three-dimensional Configuration of a Magnetic Cloud Flux Rope

• DOI: 10.3847/1538-4357/ac7803
• 发表时间: 2022-04
• 期刊: The Astrophysical Journal
• 作者: Q. Hu;Chunming Zhu;W. He;J. Qiu;L. Jian;A. Prasad

An Eruptive Circular-ribbon Flare with Extended Remote Brightenings

• DOI: 10.3847/1538-4357/ab9cbe
• 发表时间: 2020-07
• 期刊: The Astrophysical Journal
• 作者: Chang Liu;A. Prasad;Jeongwoo Lee;Haimin Wang

A magnetic flux rope configuration derived by optimization of two-spacecraft In-situ measurements

• DOI: 10.3389/fphy.2022.960315
• 发表时间: 2022-06
• 作者: Q. Hu;W. He;Yu Chen