Discrete plasmaspheric emissions—The generating mechanism and propagation

Abstract

An attempt is made to interpret discrete VLF emissions observed in the plasmasphere in terms of quasi-electrostatic whistler mode waves, generated in the near-equatorial region and propagating downward in the quasi-resonance mode. The generating mechanism is assumed to be the kinetic instability connected with loss cone and temperature anisotropy of the distribution function of low-energy electrons. The observed low-frequency limit of discrete plasmaspheric emissions can be explained by quasi-resonance mode propagation in the dense plasma of the plasmasphere. The possible connection of these emissions with half-gyrofrequency VLF emissions and the correlation with the simultaneously measured electron temperature enhancements are discussed.