Nonlinear Interactions Between Relativistic Electrons and EMIC Waves in Magnetospheric Warm Plasma Environments

Abstract

AbstractWith the kinetic dispersion relation and test particle simulation, we examine the effect of hot protons on the nonlinear interactions of relativistic electrons with electromagnetic ion cyclotron (EMIC) waves. We find that hot protons alter the refractive index of EMIC waves at a given wave frequency along latitude and thus modify resonance latitude. Consequently, resonance refractive index gradient along the magnetic field line, which plays a dominant role in controlling the electron behaviors, changes. Overall, the involvement of hot protons enlarges the resonance region (linear and nonlinear) but narrows the nonlinear resonance region. Additionally, hot protons weaken the electron phase bunching process and shift the electron phase trapping region to larger equatorial pitch angles. When the abundance or temperature anisotropy of hot protons increases, their effects on electron behaviors become more significant.