Collaborative Research: GEM--Energetic Electron Nonlinear Interactions with Oblique Whistler-Mode Chorus Waves

合作研究：GEM--高能电子与斜惠斯勒模式合唱波的非线性相互作用

• 批准号: 2225122
• 负责人: Homayon Aryan
• 金额: $ 11.19万
• 依托单位: University of California-Los Angeles
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-10-01 至 2025-09-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2225122&HistoricalAwards=false
• 关键词: Collaborative; Research; GEM; Energetic; Electron

Whistler-mode "chorus" waves are naturally occurring radio emissions in Earth's outer radiation belt. These waves can resonantly interact with trapped energetic electrons (~10 keV to 1 MeV), both accelerating them to high speeds and scattering them into the atmosphere as "particle precipitation." Intense chorus waves, propagating at oblique angles to the background magnetic field, invoke such resonances in multiple harmonics and produce strong electron responses on rapid timescales, within tens of seconds. However, the role of different resonance harmonics in shaping the global state of the radiation belt remains unknown. This investigation will study the interactions between electrons and these intense oblique chorus waves to address this problem. Understanding the properties and mechanisms of these processes is important for forecasting space weather and its effects on sensitive systems, such as spacecraft surfaces and electronics. This project will also support early-career scientists and a graduate student, and the findings will be incorporated into public outreach materials and undergraduate classes at the University of Texas at Dallas.The goal of this project is to address three specific scientific questions: 1) How does energetic electron phase space density evolve under nonlinear wave-particle interactions with oblique whistler-mode chorus waves? 2) Are there observable distinctions between different electron harmonic resonances with magnetospheric chorus waves and, if so, what are they? 3) What are the respective roles of Landau and cyclotron resonances in shaping the outer radiation belt in events with intense oblique chorus waves? To answer these questions, we will develop numerical models of both oblique chorus wave packets and electron phase space density evolution, and quantitatively compare model results with in-situ measurements made by NASA's Van Allen Probes. Importantly, this research may lead to the discovery of direct observational evidence of electron nonlinear resonances in distinctive harmonics, including Landau resonance. These important processes have been theorized to occur in outer space but have yet to be confirmed with experimental evidence.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.

惠斯勒模式“合唱”波是地球外辐射带中自然存在的无线电排放。这些波可以与被困的能量电子（〜10 keV至1 meV）共同相互作用，既可以将它们加速到高速，又将它们散布到大气中，以“颗粒沉淀”。强烈的合唱波，与背景磁场的倾斜角度传播，在多个谐波中引起这种共振，并在数十秒内的快速时尺度上产生强烈的电子响应。但是，不同共振谐波在塑造辐射带的全球状态中的作用仍然未知。这项研究将研究电子与这些强烈的倾斜合唱波之间的相互作用，以解决这个问题。了解这些过程的特性和机制对于预测空间天气及其对敏感系统（例如航天器表面和电子产品）的影响很重要。该项目还将支持早​​期职业科学家和研究生，这些发现将在得克萨斯大学达拉斯分校的公共外展材料和本科课程中纳入公共外展材料和本科课程。该项目的目的是解决三个特定的科学问题：1）能量电子相位空间空间密度如何在非线性波 - 在非线性波 - 在越野型惠斯勒式校友chorus chorus chorus chorus chorus chorus chorus chorus chore ods swords互动？ 2）与磁层合唱波之间不同的电子和声共振之间是否有明显的区别，如果是，它们是什么？ 3）在强烈的斜合唱波中，兰道和回旋子共振在塑造外部辐射带中的作用是什么？为了回答这些问题，我们将开发出斜合唱波数据包和电子相空间密度演化的数值模型，并定量将模型结果与NASA的VAN ALLEN探针进行的原位测量结果进行了比较。重要的是，这项研究可能导致在包括Landau共鸣在内的独特谐波中发现电子非线性共振的直接观察证据。这些重要的过程已经在外太空中发生，但尚未通过实验证据进行确认。该奖项反映了NSF的法定任务，并认为使用基金会的知识分子优点和更广泛的影响评估标准，认为值得通过评估来获得支持。