Nonlinear Interaction of Landau-Resonance Electrons with the EMIC Wave in a Multicomponent Plasma

Nonlinear resonant interaction between the electromagnetic ion-cyclotron (EMIC) wave and magnetospheric electrons at the Cerenkov resonance, also referred to as the Landau or the zero-order cyclotron resonance, is investigated. Based on the data obtained on September 10, 2017, by one of the Van Allen Probe (RBSP) spacecrafts, the trajectory of a monochromatic wave packet in an inhomogeneous multicomponent plasma is found. The amplitude of the wave along the propagation trajectory is calculated taking into account not only the linear resonant interaction with protons and electrons but also variation of geometric factors such as the group velocity and the ray tube cross section. Numerical integration of the nonlinear system of equations describing the motion of electrons in the field of modeled packet of the EMIC waves revealed an important role played by nonlinear effects in the dynamics of resonant particles.