Superposed Epoch Analysis of the Energetic Electron Flux Variations During CIRs Measured by BD‐IES.

The flux variations of energetic electrons is one of the most important topics to understand dynamic processes in the space environment and the forecast for high‐energy electron burst. BeiDa Image Electron Spectrometer (BD‐IES), an imaging energetic elecstron spectrometer onboard a Chinese navigation satellite at an inclined geosynchronous orbit, can provide 50–600 keV electron flux data, which is used to investigate electron flux variations at GEO orbit during Co‐rotating Interaction Region events (CIRs). The superposed epoch analysis is applied to study the electron flux variations in different energy channels of BD‐IES during CIRs and the results support previous works. It reveals that electron fluxes in different channels all have a dropout before or at CIR interface and then the recovery of electrons with low energy reaches maximum earlier than that of electrons with high energy, with longer time differences for larger energy gap, which is consistent of two major mechanisms for energizing particles: inward radial diffusion and local acceleration. In addition, we investigate the relationship between electron flux enhancement in each energy channel and magnetic locals time and the extent of enhancement for electron flux peak value compared with average value before interface. These results can contribute to our understanding of electron flux variations at GEO during CIRs, and thus lay foundations for forecast research on high‐energy electron enhancement during CIRs. Key Points: Energetic electron flux variations at GEO during CIRs are studied using the observations from BD‐IES, the first mid‐energy electron detector in ChinaSuperposed epoch analysis reveals that there are time delays between the peaks of low‐ and high‐energy electron enhancements, with longer delay for larger energy gapRelatively low‐energy electrons tend to have MLT dependence during the enhancement process, while higher‐energy electrons could reach an approximately equal level of enhancement in every MLT sector [ABSTRACT FROM AUTHOR]