On the Possibility of Driving the Electron Flux Probabilistic Models by the AE Index

Abstract We present the new probabilistic model of the electron fluxes designed to assess the risks of the spacecraft surface charging for missions with near‐equatorial orbits in the inner magnetosphere. It is a second model developed within a frame of the European Space Agency's activity “Plasma Environment Modeling in the Earth's Magnetosphere” (PEMEM). The first model PEMEM Percentile (Dubyagin et al., 2024, https://doi.org/10.1029/2023JA032026 ) has a robust though somewhat simple functionality. Addressing the PEMEM Percentile weaknesses, we test a novel approach to incorporating the dependence on geomagnetic activity in probabilistic models. The model is based on Van Allen Probes particle data. The model is driven by the auroral electrojet (AE) index from a period in the past corresponding to the expected solar cycle phase during a mission lifetime. The main model inputs are the spacecraft orbit, the time interval of AE‐index to drive the model, and the confidence levels. For given confidence levels, the model outputs the worst‐case 1–100 keV integrated electron flux and corresponding differential flux spectrum. The model can output these parameters separately for the eclipse and sunlit parts of the orbit. While investigating the response of the electron flux to the AE‐index variations, we have found that lower energy electrons reveal the highest correlation with the AE‐index averaged over the substorm time scale, while higher energy electrons show a higher correlation with AE on the storm time scale. The transition between these two regimes occurs at keV energy and has a complex dependence on radial distance and MLT.