Abstract:

The high energy (> ~500 keV) electron flux in the Earth’s radiation belts is highly variable and has been observed to change by orders of magnitude within a few hours. As society is becoming increasingly reliant on satellite technology it is important to understand, and ultimately predict, these changes as high energy electrons are responsible for potentially damaging internal charging in satellites. The increasing use of medium Earth orbit (MEO) means that modelling the radiation environment throughout the radiation belts is particularly relevant, as there is relatively little long-term data available at MEO.

The BAS Radiation Belt Model has been developed to model the drift-averaged, high-energy electron flux from the inner edge of the outer belt to the last closed drift-shell. I will describe the model and present some recent results including the first very long-term simulation (30 years) showing the ‘climatology’ of the outer radiation belt and slot region, an explanation of the “impenetrable barrier” observed by Baker et al. (2014) and the consequences of the slot region filling that can be seen during active conditions. Additionally, I will discuss how the model has been adapted for use in forecasting.