Physical Links between Coronal Mass Ejection (CME) Velocity and Source Region Parameters

首席研究员（PI）和他的团队将调查给定太阳源区域上方日冕中磁通量的高度剖面（或衰减指数）与已知的磁通量绳的“环面不稳定性”之间的物理关系。他们打算证明，这种相互作用在日冕物质抛射（CME）源区的磁结构和CME的最终喷发速度之间提供了一个关键的联系。研究小组希望确定这种物理影响会影响高空日冕场的极性结构，以及日冕抛射速度与太阳源区的大小和复杂性、前体日冕抛射的发生以及太阳大规模日冕密度结构之间的关系。PI的参数化数值研究将量化高度剖面和日冕密度结构如何控制代表日冕抛射磁通量的不稳定磁通量绳的峰值上升速度。在考虑双极、四极和更复杂的通量分布的情况下，将研究高度剖面的陡峭度与光球场结构的关系，以便建立CME速度对直接可观测的源区域参数的定量依赖关系。这些结果将通过几种方法得到验证，包括在现实的热和磁条件下选择CME事件的数值模拟，这些事件涵盖了中等到极高的速度范围，以及对CME速度的统计研究，其中将首次包括日冕磁场的高度剖面（通过外推获得）和新确定的源区域参数。日冕中日冕物质抛射的峰值速度是有效的空间天气预报的关键参数，因为日冕物质抛射的到达时间和潜在影响可能会威胁到美国的宇航员、卫星和地面技术。该项目将通过在预测科学公司（PSI）和乔治梅森大学（GMU）之间建立新的合作伙伴关系，建立太阳物理学的研究基础设施。这些研究成果将在评审文献以及科学讲习班和会议上广泛传播。研究的日冕物质抛射事件目录，包括源区域参数、现场外推和高度剖面，将在PSI和GMU的网页上提供，供社区访问，并且PI的模拟输出也将应要求提供。该项目将在GMU培训一名研究生，并支持PSI博士后太阳物理学家的专业发展。

The Principal Investigator (PI) and his team will investigate the physical relationship between the height profile (or decay index) of the magnetic flux in the corona above a given solar source region and the known 'torus instability' of magnetic flux ropes. They intend to establish that this interaction provides a key link between the magnetic structure of the source region of a coronal mass ejection (CME) and that CME's ultimate eruption velocity. The team expects to determine that this physical influence affects the coronal field's polarity structure at great heights, as well as the association of CME velocity with solar source region size and complexity, the occurrence of precursor CMEs, and the Sun's large-scale coronal density structure. The PI's parametric numerical investigation will quantify how the height profile and the coronal density structure control the peak rise velocity of unstable magnetic flux ropes, which represent the erupting magnetic flux in CMEs. The steepness of the height profile will be investigated in relation to the structure of the photospheric field while considering bipolar, quadrupolar, and more complex flux distributions, in order to establish quantitative dependencies of the CME velocity on the directly observable source region parameters. These results will be verified by several means, including numerical modeling of selected CME events under realistic thermal and magnetic conditions with events covering a range of moderate to extremely high velocities, and statistical studies of CME velocities that will include, for the first time, the height profiles of the coronal magnetic field (obtained by extrapolations) and newly identified source region parameters. The peak CME velocity in the solar corona is a key parameter for effective space weather forecasting, since the arrival time and potential impact of CMEs may threaten the nation's astronauts, satellites, and ground-based technologies. This project will build research infrastructure in solar physics by creating a new partnership between Predictive Science, Inc. (PSI) and George Mason University (GMU). These research results will be broadly disseminated in the refereed literature as well as at science workshops and conferences. A catalog of studied CME events, including source region parameters, field extrapolations, and height profiles, will be provided on PSI and GMU web pages for community access, and the PI's simulation output will also be made available upon request. This project will train a graduate student at GMU and support the professional development of a postdoctoral solar physicist at PSI.