GEM: Multipoint Observations and Global Modeling of Energetic Particle Deep Penetration into the Low L Region of Earth's Inner Magnetosphere

GEM：高能粒子深度穿透地球内磁层低 L 区域的多点观测和全局建模

• 批准号: 2140934
• 负责人: Hong Zhao
• 金额: $ 38.32万
• 依托单位: Auburn University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-01-01 至 2024-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2140934&HistoricalAwards=false
• 关键词: GEM; Multipoint; Observations; Global; Modeling

Understanding the relativistic particle environment surrounding Earth is vital to predict and mitigate space weather effects. These effects include damage to satellites in low-Earth orbit. This project addresses an important question of how particles are accelerated in the inner magnetosphere through a combination of observational studies and state-of-the-art modeling. Two early career researchers are supported.The main goal of this project is to investigate and quantify the role of electric fields in the deep penetration of energetic electrons and protons using data from the Van Allen Probes and THEMIS as well as modeling with the RCM-E and a 3-D particle tracer. Specific science questions to be addressed are: 1) Based on the multipoint observations, what are the quantitative differences between energetic electron and proton deep penetration into the low L region in penetration depth, frequency, timing, and MLT distribution? 2) Based on the multipoint observations, what is the spatiotemporal evolution of electric fields in the inner magnetosphere during energetic particle deep penetration events? 3) To what extent can the RCM-E represent the observed electric fields in the inner magnetosphere during deep penetration events? 4) To what extent can the electric fields given by RCM-E explain the differences in deep penetration of inner magnetospheric energetic particles of different species and/or energies? To answer these science questions, energetic particle deep penetration events down to L4 will be identified using data from the Van Allen Probes, and the penetration depth, timing, and MLT dependence will be examined. The electric field measurements from EFW on Van Allen Probes and EFI on THEMIS will be examined, and the spatiotemporal evolution of electric fields will be investigated. The RCM-E will be used to model self-consistent, time-varying electric fields in the inner magnetosphere to be compared to the observations. The modeled electric fields will then be embedded into a particle tracer to examine whether the observed energetic particle deep penetration, especially the differences between electron and proton penetration, can be explained by the transport of inner magnetospheric populations by the modeled electric field of RCM-E.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.

了解地球周围的相对论粒子环境对于预测和减轻空间天气影响至关重要。这些影响包括对近地轨道卫星的损坏。该项目通过结合观测研究和最先进的建模，解决了粒子如何在内磁层中加速的重要问题。支持两名早期职业研究人员。该项目的主要目标是使用范艾伦探针和 THEMIS 的数据以及 RCM-E 建模来研究和量化电场在高能电子和质子深度穿透中的作用和 3D 粒子示踪剂。具体需要解决的科学问题是： 1）基于多点观测，高能电子和质子深入低L区在穿透深度、频率、时间和MLT分布方面存在哪些定量差异？ 2）基于多点观测，高能粒子深穿透事件期间内磁层电场的时空演化是怎样的？ 3）RCM-E在多大程度上可以代表深穿透事件期间观测到的内磁层电场？ 4）RCM-E给出的电场在多大程度上可以解释不同种类和/或能量的内磁层高能粒子深度穿透的差异？为了回答这些科学问题，将使用范艾伦探测器的数据来识别低至 L4 的高能粒子深度穿透事件，并检查穿透深度、时间和 MLT 依赖性。将检查范艾伦探针上的 EFW 和 THEMIS 上的 EFI 的电场测量结果，并研究电场的时空演化。 RCM-E 将用于模拟内磁层中自洽、时变的电场，以便与观测结果进行比较。然后将模型化的电场嵌入到粒子示踪器中，以检查观察到的高能粒子深度穿透，特别是电子和质子穿透之间的差异，是否可以通过 RCM-E 模型化电场的内磁层群体传输来解释该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Multi‐Event Study on the Connection Between Subauroral Polarization Streams and Deep Energetic Particle Injections in the Inner Magnetosphere

亚极光偏振流与内磁层深部高能粒子注入之间联系的多事件研究

• DOI: 10.1029/2021ja029895
• 发表时间: 2022-01
• 期刊: Journal of Geophysical Research: Space Physics
• 作者: Califf, S.;Zhao, H.;Gkioulidou, M.;Manweiler, J. W.;Mitchell, D. G.;Tian, S.
• 通讯作者: Tian, S.