地球辐射带区域哨声模波动对太阳风动压扰动的快速响应

The cyclotron resonance driven by whistler-mode waves (plasmaspheric hiss, exohiss and chorus) is an important mechanism controlling the radiation belt electron dynamics. Hence, understanding and predicting the evolution of radiation belt electrons require the information about the generation, distribution and evolution of these whistler-mode waves. In the previous studies, the substorm activity has been found to largely determine the distribution of whistler-mode waves. Recently, a series of case studies have shown that, some changes of solar wind dynamic pressure can lead to the prompt variation of whistler-mode waves in the radiation belt region (e.g., the disappearance of plasmaspheric hiss induced by the interplanetary shock and the simultaneous disappearances of plasmaspheric hiss, exohiss and chorus induced by the sudden decrease of solar wind dynamic pressure). Here we will systematically analyze the data from Van Allen Probes, THEMIS, CLUSTER, and MMS satellites, investigate the prompt response of radiation belt whistler-mode waves to the solar wind dynamic pressure disturbances, and understand the generation, distribution and evolution of these whistler-mode waves in depth.

哨声模波（等离子体层嘶声、外嘶声和合声）驱动的回旋共振是控制辐射带电子演化的重要机制。研究哨声模波动的产生、分布和演化是理解和预报电子辐射带动态变化的关键环节。以往众多的研究关注于磁层亚暴活动对这些哨声模波动的调控作用。近期一系列的事例研究发现，某些太阳风动压变化能够立即影响辐射带区域哨声模波动的分布（例如，行星际激波引发等离子体层嘶声的消失，太阳风动压下降引发三种哨声模波的同时消失）。本项目计划分析Van Allen Probes、THEMIS、CLUSTER和MMS等卫星观测数据，系统考察辐射带区域三种哨声模波对太阳风动压变化的快速响应特征，深入理解这些哨声模波的产生、分布和演化规律。

等离子体波是空间无碰撞等离子体中能量传输的重要媒介。本项目分析了RBSP、THEMIS、 Arase和MAVEN等卫星观测数据，系统考察了地球内磁层多种等离子体波对太阳风动压脉冲的即时响应，结合等离子体线性不稳定计算和动力学模拟，深入研究了这些等离子体波的形成机制、时空分布规律和对带电粒子的影响，并进一步将波粒相互作用机制推广至火星诱导磁层中。代表性成果包括：（1）发现太阳风动压脉冲导致地球磁层等离子体波的增强、消失和周期性变化；（2）揭示地球等离子体层嘶声波的内部源头、全球传播和加热效应；（3）确定地球磁层磁声波的激发条件和位置以及火星诱导磁层磁声波的加热效应。系列研究有助于深入认识太阳风和地球磁层的耦合过程以及地球和火星（诱导）磁层中等离子体波的能量转化和转移过程。