Nonlinear Wave-Particle Interactions in the Earth’s Inner Magnetosphere: Dynamic Variation of the Earth’s Outer Radiation Belt Due to Whistler-Mode Chorus and EMIC Waves

摘要

Since publication of our previous summary paperon nonlinear wave-particle interactions, published in theRadio Science Bulletin [1], we have achieved a numberof advances in the study on the variation of the Earth’souter radiation belt. This paper summarizes our updatedunderstanding of the dynamics of radiation-belt electrons(MeV) interacting with whistler-mode chorus emissions andelectromagnetic ion-cyclotron (EMIC) waves, generatedthrough nonlinear interactions with energetic electrons andprotons (10-100 keV) injected from the magnetotail at thetime of magnetic disturbances. This paper is not a reviewpaper comprehensively covering all important papers of thetopics, but it is a summary of recent papers from our researchgroup on nonlinear wave-particle interactions related to thedynamics of the radiation belt. The major results are thatrapid formation of the relativistic electron fl ux takes placethrough acceleration due to nonlinear wave trapping bywhistler-mode rising-tone chorus emissions. A substantialamount of relativistic electron fl ux in the outer radiationbelt is precipitated through pitch-angle scattering due tononlinear interaction with EMIC rising-tone emissions.