What the detailed properties of MeV electron microbursts reveal about their scattering mechanisms and contribution to radiation belt loss

Abstract

The outer radiation belt is a highly dynamic region of the Earth's magnetosphere, with often-unpredictable variations in intensity and spatial extent. Characterization of this variable radiation environment is critical to mitigating spacecraft anomalies often caused by energetic particles. The physical processes controlling the acceleration and loss of trapped relativistic electrons in the radiation belts are complex and there are a number of competing processes that can combine to produce net enhancements or depletions of the belts. Precipitation into the atmosphere has been shown to be an important loss process for energetic particles in Earth's magnetosphere, but when, where, and how much precipitation contributes remain open questions. While radiation belt diffusion models can now reproduce observed acceleration events quite accurately, radiation belt depletion events are often less well-captured. Quantification of precipitation loss, as well as understanding of the physical mechanisms producing it, is thus critical to our understanding of the dynamics of the outer radiation belt.