基于Arase卫星数据的地球电子外辐射带数据同化建模  

Data assimilative modeling of the Earth's radiation belt electrons based on the Arase satellite observations

作　　者：罗陶荣 倪彬彬[1] 曹兴 王晓宇[1] 雷源 LUO TaoRong;NI BinBin;CAO Xing;WANG XiaoYu;LEI Yuan(School of Earth and Space Science and Technology,Wuhan University,Wuhan 430072,China)

机构地区：[1]武汉大学地球与空间科学技术学院,武汉430072

出　　处：《地球物理学报》2025年第4期1187-1200,共14页Chinese Journal of Geophysics

基　　金：国家自然科学基金(42025404,42188101,42374193);国家重点研发计划(2022YFF0503700,2022YFF0503900);中国科学院先导B计划(XDB41000000)资助。

摘　　要：Arase卫星是一颗专门探测地球辐射带的科学卫星,于2016年12月20日成功发射.在2019年10月范艾伦卫星终止运行后,Arase卫星仍然继续正常运行并提供高质量的观测数据.本文结合Arase卫星高能电子探测器的电子通量观测数据和基于Fokker-Planck扩散方程的三维辐射带数值模型,利用卡尔曼滤波方法实现对2017年4月至2022年3月期间地球外辐射带(L^(*)=3~7)电子通量时空演化过程的数据同化建模.结果显示,同化模型有效弥补了Arase卫星数据对于高赤道投掷角电子的观测缺失,重构了不同能量、投掷角辐射带电子在不同L^(*)处的长期动态演化过程及其对地磁活动的响应特征.通过计算电子通量的数据同化结果与卫星观测结果之间的皮尔逊相关系数、平均误差、平均绝对误差和均方误差,发现电子通量同化结果和观测结果整体一致.通过计算同化过程中的新息矢量,分析卫星观测结果对辐射带数值模型模拟结果的修正程度及其对电子能量和L^(*)的依赖性,这为分析辐射带数值模型所缺失的物理机制以及后续模型的改进与完善提供了重要参考.The Arase satellite,a scientific satellite dedicated to the detection of the Earth's radiation belts,was successfully launched on 20 December 2016.After the termination of the Van Allen satellites in October 2019,the Arase satellites continue to operate normally and provide high-quality observations.In this paper,the data assimilation modeling of the spatial and temporal evolution process of the electron flux in the outer radiation belts of the Earth(L^(*)=3~7)for the period of April 2017 to March 2022 is achieved by using the Kalman filter method in conjunction with the electron flux observation data from the high-energy electron detector of the Arase satellite and the numerical model of the three-dimensional radiation belts based on the Fokker-Planck diffusion equation.The results show that the assimilation model effectively compensates for the missing observation of Arase satellite data for electrons with high equatorial pitch angles,and reconstructs the long-term dynamic evolution process of radiation belt electrons with different energies and pitch angles at different L^(*)and their response characteristics to geomagnetic activities.By calculating the Pearson correlation coefficient,mean error,mean absolute error and mean square error between the data assimilation results of the electron fluxes and the satellite observations,it was found that the electron flux assimilation results and the observations were in overall agreement.By calculating the innovation vectors in the assimilation process,we analyze the degree of correction of the satellite observations to the simulation results of the numerical model of the radiation belts and its dependence on the electron energy and L^(*),which provides significant references for the analysis of the missing physical mechanisms of the numerical model of the radiation belts as well as the subsequent improvement and refinement of the model.

关 键 词：Arase卫星 地球辐射带 电子通量 三维数据同化 模型性能 

分 类 号：P353[天文地球—空间物理学]