The Phase Space Density Evolution of Radiation Belt Electrons under the Action of Solar Wind Dynamic Pressure

Earth’s radiation belt and ring current are donut-shaped regions of energetic relativistic particles, trapped by the geomagnetic field. The strengthened solar wind dynamic pressure (Pdyn) can alter structure field, which bring about variation current. In study, we firstly utilize group test particle simulations to investigate phase space density (PSD) under varying field modeled International Geomagnetic Reference Field (IGRF) T96 magnetic models from 19 December 2015 20 2015. Combining observation Van Allen Probe, find that PSD outer electrons evolves towards different states levels Pdyn. first stage, Pdyn (~7.94 nPa) results in obvious rise electron anisotropy. second there is a significant reduction for at all energy pitch angles action intense (~22 nPa), suggests magnetopause shadowing outward radial diffusion play important roles process. result study help us further understand evolution during period disturbance.