电磁离子回旋波（EMIC）是影响磁层粒子动力学演化过程的一种重要等离子体波动，尤其是对辐射带高能电子的散射损失有关键作用，故深入研究EMIC波在空间天气预报领域具有重要的理论和应用意义。色散关系是研究波与磁层粒子相互作用的基础，其与等离子体环境参数密切相关。由于部分关键参数很难直接测量，目前EMIC-电子相互作用的研究多采用固定的等离子体成分参数和冷等离子体近似，而忽略了等离子体环境的动态变化和热离子引入的动力学效应等因素。本项目旨在前期研究的基础上，从MMS卫星多点同步观测数据出发利用相位差法直接重构EMIC波的波矢，并深入研究其色散关系时空特性，通过建立与理论色散关系的对比模型，进一步完善对EMIC波的理解；基于直接获得的色散关系，求解Fokker-Planck扩散方程，结合Van Allen Probes观测数据，系统地定量分析EMIC波影响磁层高能电子的物理过程。

Electromagnetic ion cyclotron (EMIC) waves play crucial roles in the dynamic of terrestrial magnetospheric particles, especially in the relativistic electron scattering lose in radiation belts. Hence, the study on EMIC waves is essential for the space weather forecasting. Because the dispersion relation, which is critical for the wave-particles interactions, depends on rarely available ion compositions and cold or hot plasma environment measurements, most of previous works adopted fixed plasma parameters and/or cold plasma approximation for EMIC-electron interaction studies. However, the dynamic variations of plasma environment and the kinetic effects introduced by hot plasmas may not be negligible. In this project, we shall determine the wave vector and dispersion relation of EMIC waves experimentally by using the multi-point synchronous observations from MMS. We shall study the spatial and temporal characteristics of the EMIC dispersion relation, and comparatively analyze the theoretical and experimental results to enrich our understanding of EMIC waves. Moreover, using the Van Allen Probes observations, we shall solve the corresponding Fokker-Planck diffusion equation based on the experimental dispersion relation, and quantify the variations of high-energy electrons introduced by EMIC waves.