Electron Dynamics and Whistler‐Mode Waves Inside the Short Large‐Amplitude Magnetic Field Structures

Abstract

AbstractWe investigate the electron dynamics and generation of whistler‐mode waves inside a short large‐amplitude magnetic structure (SLAMS) based on Magnetospheric Multiscale Satellite observations and test particle simulations. The buildup of energetic reflected ions caused by the SLAMS's intense magnetic fields favors the resonance condition of solar wind ions of ion‐ion non‐resonant mode. This might further steepen the SLAMS, leading to the Betatron acceleration of electrons and generating the whistler‐mode waves locally ahead of the peak of the magnetic field. In regions behind the peaked magnetic field, electrons are decelerated by the convection electric field during gradient drift and the whistler‐mode waves are rapidly decayed. Our study provides new insights into electron acceleration and the generation of whistler‐mode waves near the quasi‐parallel shock.