Collaborative Research: Quantifying the Effects of Nonlinear Wave-particle Interaction in the Inner Magnetosphere

惠斯勒波是由闪电以极低的频率产生的无线电波。它们被认为在辐射带和更广泛的磁层动力学中起着重要作用。这项工作将涉及这些波的理论和观测研究以及它们与磁层中相对论性粒子的相互作用。研究结果可直接应用于空间天气模型，这是国家空间天气行动计划中提出的优先事项。此外，将支持两名研究生，并加强多个机构的等离子体物理学家和空间物理学家之间的合作。为了量化非线性波粒共振相互作用，本项目将解决三个问题（即目标）：(1)在磁层内部检测到足够强烈的哨声波的频率，这将提供非线性波粒相互作用的发生率；(2)如何描述强哨声波对电子通量演化的影响，这将为评价具有非线性波粒相互作用的地球间隔系统中的电子分布提供理论工具；(3)非线性波粒相互作用对波的产生和阻尼的影响，这将为磁层内非线性波的增长/阻尼率提供一个有效的模型。三个目标中的每一个都结合了观测（来自忒弥斯和范艾伦探测器）和理论研究。该奖项反映了美国国家科学基金会的法定使命，并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，被认为值得支持。

Whistler waves are radio waves produced at very low frequencies by lightning. They are believed to have an important role in the dynamics of the radiation belts and broader magnetosphere. This work will involve theoretical and observational studies of these waves and their interactions with relativistic particles in the magnetosphere. The results have direct applications in space weather models, which are a priority set out in the National Space Weather Action Plan. Additionally, two graduate students will be supported and collaborations will be strengthened between plasma physicists and space physicists at multiple institutions.To quantify nonlinear wave-particle resonant interactions, three questions will be addressed (i.e., objectives) in this project: (1) how often sufficiently intense whistler waves are detected in the inner magnetosphere, which will provide the occurrence rate of nonlinear wave-particle interactions; (2) how to describe the impact of intense whistler waves on electron flux evolution, which will provide a theoretical tool to evaluate electron distributions in the geospacer system with nonlinear wave-particle interactions; and (3) what is the effect of nonlinear wave-particle interactions on wave generation and damping, which will provide a validated model of the nonlinear wave growth/damping rate in the inner magnetosphere. Each of the three objectives combines observational (from THEMIS and Van Allen Probes) and theoretical investigations.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.