Cyclotron instabilities of low frequency, parallel propagating electromagnetic waves in the magnetosphere

Electromagnetic electron- and ion-cyclotron instabilities incorporating the details of wave-particle interactions have been studied with reference to low frequency waves in the magnetosphere. The general dispersion relation for transverse electromagnetic waves propagating along the ambient magnetic field in an anisotropic bi-Maxwellian plasma with a mirror loss-cone configuration has been considered. The growth/damping rates for electron-cyclotron waves (whistler) and ion-cyclotron waves have been derived. The electron- and ion-cyclotron wave growths have been computed from the magnetospheric VLF data from ISIS-2 satellite for equatorial and midlatitude auroral regions of the magnetosphere. The dependence of the growth rate of these waves on the temperature anisotropy and mirror loss-cone has been discussed. Loss-cone and electron-cyclotron instabilities are interpreted as the generation mechanism for the low frequency waves in the magnetosphere.