NSWP: Numerical Investigation of Coronal Mass Ejection (CME) Cannibalism in the Inner Heliosphere and Its Implications for Space Weather

主要研究员将在空间天气背景下研究日冕物质抛射-日冕物质抛射相互作用和日冕物质抛射同类相食现象，重点是更准确地预测复杂事件期间以及日冕物质抛射驱动的冲击波形成和演变期间1 Au的空间环境条件。PI的动机是观察到连续的地球日冕物质抛射（CME）的相互作用与大型，长寿命的地磁风暴和大型渐进的太阳高能粒子（SEP）事件。该团队将对过去的CME事件进行详细的3D MHD数值研究，以解决基础科学问题。这些问题包括之前的CME对日光层的预处理和修改太阳到L1的磁连接的重要性，L1的现场测量与CME在前往地球的途中遇到的相互作用有何关系，以及连续CME与大SEP事件的关联是否仅仅是统计上的，或者可以从冲击的特征来理解，并与最初的日冕物质抛射对日冕的破坏有关。该团队将从他们的3D MHD模拟中直接计算可观测的量，然后将该模型输出与航天器观测结果进行比较。该项目将改进所使用的数值模型，从而使空间气象界能够处理与地球空间一些最大和持续时间最长的中断有关的问题。改进后的模型最终将通过空间气象建模框架交付给社区协调建模中心，供太阳和日光层社区更广泛地使用。该团队还将生成太阳现象的3D可视化和动画，用于夏威夷大学天文学研究所（IfA）的公共宣传和教育计划。

The Principal Investigator (PI) will study CME-CME interactions and CME cannibalism in the context of space weather, focusing on more accurate prediction of space environment conditions at 1 AU during complex events and during the formation and evolution of CME-driven shock waves. The PI is motivated by the observation that the interaction of successive Earthbound Coronal Mass Ejections (CMEs) is associated with large, long-lived geomagnetic storms and large gradual solar energetic particle (SEP) events. The team will perform detailed 3D MHD numerical studies of past CME events in order to address fundamental science questions. Such questions include the importance of preceding CMEs for preconditioning the heliosphere and modifying the Sun-to-L1 magnetic connection, how in situ measurements at L1 relate to the interactions a CME encounters on its way to Earth, and whether the association of successive CMEs with large SEP events is merely statistical, or can be understood in terms of shocks' characteristics and related to the disruption of the corona by the initial CMEs. The team will compute directly observable quantities from their 3D MHD simulations, and then compare this model output with spacecraft observations. This project will result in improvements to the numerical models being used and thus enable the space weather community to tackle problems related to some of the largest and longest lived disruptions in geospace. The improved models will ultimately be delivered to the Community Coordinated Modeling Center (CCMC), via the Space Weather Modeling Framework, for broader use by the solar and heliospheric community. The team will also generate 3D visualizations and animations of solar phenomena for use in public outreach and education programs within the University of Hawaii's Institute for Astronomy (IfA).