Bounce Resonance Scattering of Radiation Belt Energetic Electrons by Extremely Low-Frequency Chorus Waves

Bounce-resonant diffusion coefficients of radiation belt energetic electrons induced by extremely low-frequency (ELF) chorus waves are comprehensively evaluated using Van Allen Probes observations on 22 December 2014. ELF chorus waves can efficiently scatter 85° < _eq < 89° electrons with bounce resonance pitch angle scattering rates above 10^-4/s and energy scattering rates above 10^-7/s. By comparing diffusion coefficients due to bounce resonance with those due to cyclotron and Landau resonances, we found that bounce resonance diffusion rates have slight energy dependence for >100 keV electrons while Landau-resonant scattering rates decrease significantly in the MeV energy range. These findings suggest that bounce resonances by ELF chorus waves have potentially significant contributions to the dynamics of energetic electrons and should be considered in the further modeling of Earth’s radiation belts.