SHINE: Exploring Time-Dependent Ionization in Magnetic Reconnection During Solar Eruptions

磁重联是一个基本的过程，它控制着太阳和地球之间空间天气的多个方面。这一过程支配着太阳爆发事件以及它们对地球的影响。拟议的研究将为改进全球模型提供新的能力，从而加强研究和教育的基础设施。这种能力将通过提高验证空间天气模型的能力而造福社会，并且可以很容易地应用于其他天体物理系统的研究。提案团队的成员将指导本科生暑期实习生，并在科学会议上组织一场关于多样性、公平性和包容性的会议。这个计划探讨的问题是：在太阳环境中，等离子体在重联过程中的热力学历史和进化是什么？驱动太阳耀斑和日冕物质抛射的磁重联比经典机制预测的要快得多，解释通常依赖于湍流或佩切克式结构，其排气受到慢模激波的限制。在任何一种情况下，快速加热都会使等离子体剧烈地未电离。随着等离子体的膨胀和冷却，它会变得严重过度电离。如果假设电离平衡，偏离电离平衡将导致紫外光谱和极紫外图像的不准确解释，并且它们可以在数量级上影响辐射冷却速率。然而，这些偏离也为探索等离子体的热历史提供了有力的手段。该研究有可能促进对太阳喷发期间磁重联区热力学演化的认识，在那里电离状态可能远离平衡状态，基于电离平衡假设的方法可能提供不完整或误导性的温度结构信息。在MHD模拟中进行在线电离计算可以显著地扩展MHD模型的能力，并改善MHD模拟的观测预测。

Magnetic reconnection is a fundamental process that governs multiple aspects of space weather between the Sun and Earth. This process governs the solar eruptive events as well has their effects at earth. The proposed research will enhance infrastructure for research and education by making new capabilities available for improving global models. This capability will benefit society by improving the ability to validate space weather models and can easily be applied to the study of other astrophysical systems. Members of the proposal team will mentor undergraduate summer interns, and organize a session on diversity, equity, and inclusion at a scientific meeting.This proposed program explores the question: What is the thermodynamic history and evolution of plasma during reconnection in the solar environment? The magnetic reconnection that drives solar flares and coronal mass ejections is much faster than predicted by classical mechanisms, and explanations generally rely on either turbulence or on a Petschek-like configuration with exhaust bounded by slow mode shocks. In either case, the rapid heating leaves the plasma drastically underionized. As plasma expands and cools, it can become severely overionized. Departures from ionization equilibrium will lead to inaccurate interpretation of UV spectra and EUV images if equilibrium is assumed, and they can affect the radiative cooling rate at the order of magnitude level. However, these departures also offer a powerful means of exploring the thermal history of the plasma. The proposed research has the potential to advance knowledge on thermodynamic evolution in magnetic reconnection regions during solar eruption, where the ionization state can be far from equilibrium and methods based on the assumption of ionization equilibrium can provide incomplete or misleading information about the temperature structure. The in-line ionization calculation within MHD simulations can significantly extend the capability of MHD models and improve observational predictions from MHD simulations.