Response of Medium Energy Electrons Fluxes to Geomagnetic Disturbance at Low Orbit

According to the observational result of space electron environment, the medium energy electron fluxes of space radiation environment are modulated by geomagnetic activity at low earth orbit. In this paper we utilize the data of ZY-2 satellite Space Environment Monitor （SEM） system from 2004 to now, the data of American NOAA satellite （NOAA-15, NOAA-16, NOAA-17） SEM system Medium Energy Proton and Electron Detector （MEPED） from 1998 to now, and the observational result of geomagnetic activity to analyze the response characteristics of medium energy electrons fluxes to geomagnetic activity in the range of high-latitude at low earth orbit （about 500-900 km）. The results present that the fluxes of medium energy electrons are closely correlated with geomagnetic storms and substorms, the geomagnetic disturbance stronger, the enhancing of medium energy electron flux higher. While strong geomagnetic storms happen, the fluxes of medium energy electrons usually enhance 1 order of magnitude. And the absolute enhancements of daily averaged electron fluxes are correlated with the energy of electrons, the energy of electrons higher, the absolute enhancement of daily averaged electron flux larger. Usually, there is several days delay between the peak of geomagnetic disturbance and the peak of medium energy electrons fluxes.