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

SHINE：探索太阳喷发期间磁重联中的时间依赖性电离

• 批准号: 1723313
• 负责人: Chengcai Shen
• 金额: $ 35.95万
• 依托单位: Smithsonian Institution Astrophysical Observatory
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-09-01 至 2021-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1723313&HistoricalAwards=false
• 关键词: SHINE; Exploring; Time; Dependent; Ionization; SHINE; Exploring; Time; Dependent; Ionization

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.

磁重新连接是一个基本过程，它控制着太阳和地球之间空间天气的多个方面。该过程控制太阳喷发事件在地球上也具有其影响。拟议的研究将通过改善全球模型的新功能来增强研究和教育的基础设施。这种能力将通过提高验证太空天气模型的能力来使社会受益，并可以轻松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暑期实习生，并在科学会议上组织有关多样性，公平和包容性的会议。该建议的计划探讨了一个问题：在太阳能环境中重新连接期间血浆的热力学历史和进化是什么？驱动太阳耀斑和冠状质量弹出的磁重新连接要比经典机制预测的要快得多，并且解释通常依赖于湍流或具有较慢模式冲击的排气界面的Petschek样配置。无论哪种情况，快速加热都使血浆截然不同。随着等离子体的扩展和冷却，它可能会被严重上限。如果假定平衡，则偏离电离平衡将导致紫外光谱和EUV图像的解释不准确，并且可以在数量级水平上影响辐射冷却速率。但是，这些离境还提供了探索血浆热史的有力手段。拟议的研究有可能提高太阳喷发期间磁重新连接区域中热力学演化的知识，在这种情况下，离子化状态可能远非平衡和基于电离平衡假设的方法可以提供有关温度结构的不完整或误导性信息。 MHD模拟中的在线电离计算可以显着扩展MHD模型的能力并改善MHD模拟的观察性预测。