Research Article

Robust reanalysis of the electron radiation belt dynamics for physics driven space climatology applications

¹ DPHY, ONERA, Université de Toulouse, 31000 Toulouse, France
² SPARC – Space Applications and Research Consultancy, Athens 105 51, Greece

^* Corresponding author: nourallah.dahmen@onera.fr

Received: 4 July 2024
Accepted: 10 March 2025

Abstract

Specification models for radiation belts are essential for the design of radiation resistant, long-lasting spacecraft. Using the available in-situ measurements allows these models to virtually describe the average space radiation environment. However, their dependence on observations will make them suffer from data gaps which may lead to poor assessment of degradation risks. To counter this problem, one can have access to continuous descriptions of the radiation belt dynamics on long time periods through climate reanalysis. This operation consists in the assimilation of historical measurements in radiation belt simulations over solar-cycle-long periods, allowing for a physics-based filling of data gaps and the re-calibration of the radiation belt codes on long simulations. The obtained database of continuous historical distributions may serve later in the elaboration of space climatology models and a new generation of physics-based specification models. Yet, the success of climate reanalysis operation is strongly dependent on the numerical stability of the data assimilation procedure that can be deteriorated in the low earth orbit region for instance. Hence, we present in this paper, the climate reanalysis of the trapped electron dynamics using the Salammbô code for the 2014–2022 period, with promising results when compared to standard specification models. We also present the methodology followed to stabilize the assimilation in the low earth orbit.