Competing Processes of Storm-Time Ring Current and Radiation Belt Evolution

Abstract:

The energetic ion and electron populations in the Earth’s inner magnetosphere are highly dynamic during geomagnetically active periods. There are number of processes governing the energization and loss of ring current and radiation belts, such as convection, radial diffusion, wave-particle interactions, magnetopause shadowing and collisional losses. Identifying the controlling mechanisms and when and where they take place are very important in order to predict the intensity and distribution of these energetic particles. With multipoint measurements and comprehensive models available recently, it becomes possible to pinpoint the responsible processes for the observable changes. We study a few storm events using particle and field data from the Van Allen Probes, TWINS and geostationary missions. We also simulate the events with our Coupled Inner Magnetosphere-Ionosphere (CIMI) model to track energy/particle sources and losses from the major processes mentioned above. By combining data analysis and simulation methods, we seek to identify the major energization and loss mechanisms of ring current and radiation belt particles and determine how their roles change with different solar wind conditions.