VLF emissions from ionospheric/magnetospheric plasma

Abstract

VLF emissious such as hiss, chorus, oscillating tones, hiss triggerecl chorus and whistler triggered emissions have been observed at low l~.titude Indian stations. In this paper we present dynamic spectra of these emissions and discuss their various observed tea~:ures. It is argued that most of the emissions are generated during Doppter shifted cyclotron resonance interaction between the whistler mode wave and counter streaming energetic electrons. Resonance energy of the participating electron and interaction length are evaluated to explain the generation mechanism of some of these emissions observed at Indian stations.

Hiss emissions during quiet and disturbed periods

“…It can occur regardless of plasma stability conditions and the emitted wave is broad band, covering the observed frequency range. For different regions of the ionosphere and magnetosphere, the power radiated from different models of the energetic electrons had been computed [4][5][6]8,18,40,[64][65][66] and the results were compared with the observed power for mid and high latitudes. For ready reference we present selected results in figure 1.…”