SHINE: A Numerical Investigation into Coronal Mass Ejections (CME-CME) Interaction Events

日冕物质抛射（CME）是太阳系中最引人注目的事件之一，其中日冕等离子体和磁场爆炸性地释放到太空中。全面描述日冕物质抛射的日冕和行星际演化及其内部磁场结构是空间科学中最紧迫的问题之一。两个或更多的日冕物质抛射在远离太阳的过程中可能会发生碰撞，从而产生更复杂的结构，可能会增强地球上的空间天气效应。CME-CME相互作用事件已经在遥感图像和现场测量中观察到，然而，由于现有观测的稀疏性，许多悬而未决的问题仍然存在。该项目将通过磁流体动力学（MHD）模拟来解决这个问题。该项目支持一位早期职业女性PI和本科生研究人员。该项目是对CME-CME相互作用的动力学和后果的详细调查，旨在解决以下科学问题：（1）我们能否识别大多数事件共同的特征CME-CME相互作用签名，并可用作相互作用发生的代理？(2)是否有可能确定CME-CME相互作用事件的整体结构，或者每次原位观测都只是对局部性质进行采样？(3)“原始”日冕物质抛射体之间是否存在某种相互关联的特性组合，从而产生最大的地球有效性？科学问题将通过分析一系列基于理想化配置的MHD模拟来解决，这些模拟将模拟不同的CME-CME相互作用场景和所产生结构的特性。这项工作将为全面了解日冕物质抛射-日冕物质抛射相互作用过程奠定基础，其结果将适用于未来对真实的事件的原位分析。该奖项反映了NSF的法定使命，并被认为值得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来支持。

Coronal mass ejections (CMEs) are among the most dramatic events in the solar system, where coronal plasma and magnetic fields are explosively released into space. A full characterization of the coronal and interplanetary evolution of CMEs—and of their internal magnetic configuration—is one of the most pressing issues in space science. Two or more CMEs can collide during their journey away from the Sun, giving rise to even more complex structures that can potentially enhance space weather effects at Earth. CME–CME interaction events have been observed in remote-sensing imagery as well as in in-situ measurements, however, due to the sparse nature of available observations, many open questions remain. This project will address this issue through magnetohydrodynamic (MHD) simulations. The project supports an early career woman PI and undergraduate student researchers.This project is a detailed investigation into the dynamics and consequences of CME–CME interaction aimed at addressing the following Science Questions: (1) Can we identify characteristic CME–CME interaction signatures that are common to most events and can be used as proxies for interaction occurrence? (2) Is it possible to determine an overall, global structure for CME–CME interaction events, or is every in-situ observation only sampling local properties? (3) Is there a combination of properties of the “original” CMEs relative to one another that leads to maximum geoeffectiveness? The Science Questions will be addressed via analyses of a series of MHD simulations based on idealized configurations, which will model different CME–CME interaction scenarios and properties of the resulting structures. The work will lay the groundwork for comprehensive understanding of CME–CME interaction processes in the inner heliosphere, and its results will be applicable to future in-situ analyses of real events.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.