The dynamical evolution of the radiation belts has been extensively studied since their discovery in 1959. As a result, it has been found that the radiation belt electron environment originates from a delicate balance between acceleration and loss. Therefore, a proper understanding of these mechanisms may be a key to predicting the response of the belts to geomagnetic disturbances. However, analysis of radiation belt observations present a major challenge. Satellite observations are often incomplete and inaccurate and have only limited spatial coverage. Nevertheless, through data assimilation they can be blended with information from physics-based models, in order to fill gaps and lead to a better understanding of the underlying dynamical processes. Data assimilation methods have been extensively used to analyze and predict meteorological, oceanographic, and climate processes. With the advent of space-borne observational data and the development of more sophisticated space-physics models, dynamical processes in the Earth’s radiation belts can be analyzed and assessed using data assimilation methods.
We have developed a scheme that enables efficient data assimilation from multiple satellite missions (e.g. USA NASA’s Van Allen Probes and NOAA’s GOES satellites) into the state-of-the-art partial differential equation-based model of the inner magnetosphere Versatile Electron Radiation Belt (VERB-3D). This has allowed us to reconstruct the dynamics of the inner magnetosphere and has provided a comprehensive picture of the electron radiation belts.