Analysis of electron spectra observed by EPT/PROBA-V in the outer radiation belt during geomagnetically quiet and active intervals

Abstract:

The response of the inner magnetosphere to geomagnetic activity and solar wind conditions is still not fully understood. For example, electron fluxes in the outer radiation belt can be enhanced or depleted depending on the energy of the particles, and the phase or driver of a geomagnetic storm, and solar wind conditions. The Energetic Particle Telescope (EPT) on board the ESA satellite PROBA-V provides high-resolution measurements of the charged particle radiation environment in space with direct electron, proton, and heavy ion discrimination. We analyze 0.5 – 20 MeV electron spectra at several L shells bins in the outer radiation belt, and fit the observed differential flux to Maxwellian or Kappa distribution functions during different geomagnetic activity conditions (substorm and storms phases) between 2013 and 2016. In addition we compare the electron spectra with the AE8 model predictions and found that usual fluxes of energetic electrons are often lower than what is provided by the model.