Whistlers and whistler‐stimulated emissions in the outer magnetosphere

Abstract

Lightning‐generated VLF whistlers are rarely detected by the VLF receiver aboard the SCATHA satellite. This satellite has an inclination of 7.9° and covers a range of L shells from 5.5 to 9.0 near the magnetic equator. Whistlers are occasionally detected during local afternoon and evening at the lower end of the range of L shells covered by the satellite orbit. When they are detected, there is usually a well‐defined band of continuous hiss emission present. Events with whistler‐stimulated emissions have also been detected. The general absence of whistlers over most of the region of space covered by the SCATHA satellite suggests that there are few if any propagation paths from the earth‐ionosphere waveguide to the outer regions of the magnetosphere, especially to regions outside the plasmasphere. Since radiation at VLF from lightning is much stronger than power line harmonic radiation, it is unlikely that power line harmonic radiation is present outside the plasmasphere. We conclude that whistlers and power line harmonic radiation do not play a significant role in wave‐particle interactions in the outer magnetosphere.