Three-dimensional reconstruction of the dynamic evolution of the Van Allen belts using multiple satellite measurements and a diffusion model

Data assimilation aims to blend incomplete and inaccurate data with physics-based dynamical models. In the Earth's radiation belts, it is used to reconstruct electron phase space density, and it has become an increasingly important tool for validating our current understanding of radiation belt dynamics, identifying new physical processes, and predicting the near-Earth hazardous radiation environment. The dataset presents the electron flux reconstructed by assimilating electron flux measurements of the following spacecraft into the 3D Versatile Electron Radiation Belt model (VERB; Shprits et al., 2008, Subbotin and Shprits, 2009): 1. Van Allen Probes Magnetic Electron Ion Spectrometer (MagEIS; Blake et al., 2013) and Relativistic Electron Proton Telescope (REPT; Baker et al., 2013), and 2. Geostationary Operational Environmental Satellites (GOES) Magnetospheric Electron Detector (MAGED; Hanser, 2011), and Energetic Proton, Electron, and Alpha Detector (EPEAD; Onsager et al., 1996, Hanser, 2011). The method employs a split-operator Kalman filter (Shprits et al., 2013). The dataset contains electron flux for the period from 01 October 2012 00:00 UT to 01 October 2016 00:00 UT, organized in monthly files for selected values of electron energies (0.5 MeV, 1 MeV, and 2 MeV) and equatorial pitch angles (20 degree, 50 degree, and 70 degree).

数据同化（Data assimilation）旨在将不完整且存在误差的观测数据与基于物理的动力学模型相融合。在地球辐射带领域，该方法可用于重建电子相空间密度，现已成为验证当前对辐射带动力学机制的认知、识别新物理过程以及预报近地危险辐射环境的愈发重要的工具。本数据集呈现的是通过将下述航天器的电子通量观测数据同化至三维多功能电子辐射带模型（3D Versatile Electron Radiation Belt model，VERB；Shprits等，2008；Subbotin与Shprits，2009）后重建得到的电子通量：1. 范艾伦探测器搭载的磁电子离子光谱仪（Magnetic Electron Ion Spectrometer，MagEIS；Blake等，2013）与相对论电子质子望远镜（Relativistic Electron Proton Telescope，REPT；Baker等，2013）；2. 地球静止轨道环境业务卫星（Geostationary Operational Environmental Satellites，GOES）搭载的磁层电子探测器（Magnetospheric Electron Detector，MAGED；Hanser，2011）以及高能质子、电子与α粒子探测器（Energetic Proton, Electron, and Alpha Detector，EPEAD；Onsager等，1996；Hanser，2011）。本次数据同化采用了分步算子卡尔曼滤波（split-operator Kalman filter；Shprits等，2013）。本数据集涵盖2012年10月1日00:00世界时（UT）至2016年10月1日00:00世界时（UT）时段内的电子通量数据，按月度文件进行组织，涵盖预设的电子能量（0.5 MeV、1 MeV与2 MeV）以及赤道投掷角（20°、50°与70°）的参数值。