Kelvin-Helmholtz Instability and Magnetosonic Wave Emission Along Bursty Bulk Flow Channel Boudaries: Impacts on Near-Earth Plasma Sheet Dynamics During Substorms

沿突发散装流通道边界的开尔文-亥姆霍兹不稳定性和磁声波发射：亚暴期间对近地等离子体片动力学的影响

• 批准号: 2314759
• 负责人: Hava Turkakin
• 金额: $ 20.23万
• 依托单位: Utica College
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-08-01 至 2026-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2314759&HistoricalAwards=false
• 关键词: Kelvin; Helmholtz; Instability; Magnetosonic; Wave

Substorms are key elements of space weather applications and fundamental processes of solar wind energy storage and release in Earth's magnetosphere. Understanding substorm dynamics is essential in preparing for extreme space weather events, which can cause strong disruption and damage to the performances and the reliability of space-borne and ground-based technological systems. Among many physical phenomena affecting the substorm dynamics, instabilities in the magnetotail have caught much attention in recent years. This project will investigate the evolution of Kelvin-Helmholtz Instability (KHI) and magnetohydrodynamics (MHD) wave emission along Bursty Bulk Flows (BBFs) and their potential impacts on the substorm dynamics. The project results will expand our understanding of MHD waves and instabilities in the magnetotail and their association with the substorm dynamics, which will contribute to a better understanding of the magnetosphere-ionosphere coupling. Therefore, the results of this project will have direct applications in the active development of Space Weather preparedness and building capabilities to forecast space weather effects, supporting the latest focus of the National Space Weather Action Plan. This project will also support an early career female scientist from an underrepresented group, which supports NSF's Strategic Goals in diversity and promoting the advancement of women in science. Furthermore, this project will contribute to NSF's goal of developing a diverse and globally competitive STEM workforce" by involving undergraduate students from Utica University (a primarily undergraduate institution) and high school students from minority groups in the greater Utica area as summer research students. The overarching questions that motivate this investigation are: Do MHD waves occur along BBFs, and if so, how do these MHD waves impact substorm dynamics? What is the relationship between the KHI and MHD waves emission along BBFs and associated substorm dynamics? Specifically: (1) What is the likely presence of MHD waves associated with BBFs? If they are present, which solar wind conditions are more favorable for the emission of these MHD waves? (2) If MHD waves are present, are they often accompanied by KHI evolution along the BBFs? If KHI evolution is absent during MHD wave emission, what other mechanisms might cause these waves? How often and under what conditions MHD wave emission occurs with KHI evolution? (3) What are the characteristics of these MHD waves, frequencies, periods, phase velocities, etc.? Do they agree with the observed ULF wave characteristics near BBFs? (4) How do these MHD waves affect BBFs' dynamics? (5) What are the signatures of these MHD waves in the ionosphere? The team will use CMIT-LFM coupled global MHD simulations code available at NASA's Community Coordinated Modeling Center (CCMC). Simulation results will be verified with observations from the Time History of Events and Macroscale Interactions during Substorms (THEMIS) and ground-based observations from the Canadian Array for Realtime Investigations of Magnetic Activity (CARISMA).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.

亚暴是空间气象应用的关键要素，也是地球磁层太阳风能储存和释放的基本过程。了解亚暴动态对于防备极端空间气象事件至关重要，极端空间气象事件可能对天基和地基技术系统的性能和可靠性造成严重干扰和损害。在众多影响亚暴动力学的物理现象中，磁尾的不稳定性近年来引起了人们的广泛关注。本计画将探讨Kelvin-Helmholtz不稳定性（KHI）与磁流体动力学（MHD）波沿着爆发性整体流（BBF）的演化及其对亚暴动力学的潜在影响。该项目的结果将扩大我们对磁尾中的MHD波和不稳定性及其与亚暴动力学的关联的理解，这将有助于更好地理解磁层-电离层耦合。因此，该项目的成果将直接应用于积极发展空间气象准备工作和建设预测空间气象影响的能力，支持国家空间气象行动计划的最新重点。该项目还将支持来自代表性不足群体的早期职业女性科学家，支持NSF在多样性和促进妇女在科学领域的进步方面的战略目标。此外，该项目将有助于国家科学基金会的目标，发展一个多样化的和全球竞争力的干劳动力”，涉及本科生从尤蒂卡大学（主要是本科院校）和高中学生从少数群体在大尤蒂卡地区作为夏季研究生。首要的问题，激发这项调查是：MHD波发生沿着BBF，如果是这样，这些MHD波如何影响亚暴动力学？沿沿着BBF发射的KHI和MHD波与相关的亚暴动力学之间的关系是什么？具体而言：（1）与BBF相关的MHD波可能存在什么？如果它们存在，哪些太阳风条件更有利于这些MHD波的发射？(2)如果存在MHD波，它们是否经常伴随着KHI沿BBF的沿着演化？如果在MHD波的发射过程中KHI的演化不存在，那么还有哪些机制可能导致这些波的产生呢？随着KHI的发展，MHD波的发射频率和条件如何？(3)这些MHD波的特征、频率、周期、相速度等是什么？它们是否与BBF附近观测到的ULF波特征一致？(4)这些MHD波如何影响BBF的动力学？(5)电离层中这些MHD波的特征是什么？该团队将使用CMIT-LFM耦合全球MHD模拟代码，可在美国宇航局的社区协调建模中心（CCMC）。模拟结果将通过亚暴期间事件和大尺度相互作用的时间历史观测（THEMIS）和加拿大磁场活动实时调查阵列（CARISMA）的地面观测进行验证。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。