Damping of ion-cyclotron whistler waves through ionospheric plasma.

The propagation features of ion-cyclotron whistler waves through the hydrogen, helium and oxygen plasma are studied. Expression for temporal damping, spatial damping and the time development of wave amplitude is derived from the modified theory of cyclotron damping of ion-cyclotron whistler wave including thermal effect. It is shown that the temporal damping is dominant for wave frequencies closer to the ion gyrofrequencies. The variations in plasma conditions cause variation in sudden commencement of cyclotron damping, which occurs after finite time of propagation of ion whistlers. The results have been used to explain the sudden cut-off of the amplitude of ion whistler wave observed by rockets and satellites in the terrestrial ionosphere. It is shown that the present study can be used to estimate ion temperature of the plasma.