Radiation Belt Electron Scattering by Chorus Waves in Jupiter's Magnetosphere

Abstract

Whistler-mode chorus waves are recognized as key drivers of both the acceleration and loss of radiation belt electrons in Jupiter's magnetosphere. In this study, we investigate the resonant interactions between chorus waves and radiation belt electrons at L-shell = 6–12, using a newly developed empirical wave model based on combined Galileo and Juno observations. Owing to a strong dawn-dusk asymmetry in wave power distribution, electron scattering rates due to duskside chorus waves are almost an order of magnitude stronger than those due to dawnside waves. By calculating the drift- and bounce-averaged electron diffusion coefficients, we model the temporal evolution of electrons at different L-shells using two-dimensional Fokker-Planck simulations. At L-shell = 6, chorus waves exert limited effects on electrons above 200 keV and reduce the flux of electrons below 200 keV by only one order of magnitude over 100 days. At L-shell ≥ 8, chorus waves can cause efficient scattering loss of <∼MeV electrons and acceleration of higher energy electrons. The corresponding loss of lower energy electrons is found to be much more efficient than the acceleration of higher energy electrons. Furthermore, we investigate the influence of the initial energy spectrum on chorus wave-induced acceleration of radiation belt electrons. Our findings improve the current understanding of the role of chorus waves in the dynamics of Jupiter's radiation belts.