Storm-time variations of plasmaspheric ELF hiss

Abstract

ELF and VLF observational data obtained from Intercosmos-3 (August 1970–November 1970) and Intercosmos-5 (December 1971–March 1972) satellites have been analyzed. During geomagnetic storms, the generation region of plasmaspheric hiss, which is usually located near the equatorial plane just within the plasmasphere, tends to move inwards, similar to the inward motion of the plasmapause. At any phase of the storm, the source region of the plasmaspheric hiss is found in the vicinity of the slot between the two radiation belts and the inner edge of the outer radiation belt. So the storm displacement of the source region is related to the inward diffusion of the radiation belt particles ( Hess, 1968). In the main phase of the storm the relative change in the L-coordinate of the generation region of plasmaspheric hiss with respect to Dst variation is greater by one order of magnitude than that observed during the storm recovery phase. The storm variation of amplitude of the plasmaspheric hiss (in dB) is proportional, on the average, to Dst. These conclusions are in good agreement with the self-consistent theory of ELF hiss generation ( Etcheto et al., 1973).