NSWP: Modeling Coronal Mass Ejection (CME) Initiation with Magnetic Flux Emergence

该研究小组将通过模拟从对流区涌入日冕的通量形成太阳活动区，来研究日冕物质抛射(CME)的根本原因。为了实现他们的目标，团队成员将利用密歇根大学辐射激波流体动力学中心(CRASH)正在开发的新的磁流体动力学(MHD)程序。该碰撞程序在密歇根开发的现有模型的MHD能力基础上增加了辐射传输和状态方程的高级处理，并将允许在单个计算域内模拟从湍流对流区到日冕的通量涌现。该项目的首席研究员将把这一数值通量涌现部分纳入密歇根州的空间天气模型框架，以便将太阳活动区尺度的模型与延伸到地球的全球尺度的日冕模型耦合起来。该模型的预测将与太阳大气中不同层次的观测结果进行比较，包括用日震学确定的对流区等离子体流场，用多普勒图确定的日冕流场，以及用矢量磁强计测量的光球层磁场。这个新的耦合模拟系统将通过模拟从对流区涌出的磁通量进入日冕，爆发，然后作为CME传播到星际空间，来实现国家空间天气计划的一个关键目标。因此，它跨越了从太阳到地球的空间天气预报领域。这项研究还将支持本科生和研究生教育。具体来说，申请的资金将主要支持一名研究生，而研究成果将被纳入密歇根大学大气、海洋和空间科学系的课程。

This research team will investigate the fundamental causes of coronal mass ejections (CMEs) using simulations of solar active region formation by flux emergence from the convection zone into the corona. To accomplish their goals, the team members will utilize a new magnetohydrodynamics (MHD) code being developed by the Center for Radiation Shock Hydrodynamics (CRASH) at the University of Michigan. This CRASH code adds radiation transport and advance treatment of the equation-of-state to the MHD capabilities of existing models developed at Michigan, and will allow the simulation of flux emergence from a turbulent convection zone to the corona in a single computational domain. The Principal Investigator of this project will incorporate this numerical flux emergence component in Michigan's Space Weather Modeling Framework, in order to couple the solar-active-region-scale model to a global-scale coronal model extending to the Earth. The model's predictions will be compared to observations made at different levels in the solar atmosphere, including plasma flow fields in the convection zone determined with helioseismology, flow fields in the corona determined with Dopplergrams, and magnetic fields measured at the photosphere with vector magnetographs.This new coupled modeling system will address a key National Space Weather Program objective by simulating magnetic flux emerging from the convection zone into the solar corona, erupting and then propagating as a CME into interplanetary space. It thus spans the space weather forecasting domain from Sun to Earth. This research will also support undergraduate and graduate education. Specifically, the requested funding will primarily support a graduate student, while research results will be incorporated into courses in the Department of Atmospheric, Ocean, and Space Science at the University of Michigan.