Influence of Relativistic Electron Precipitation on the Lower Ionosphere and Stratosphere

Abstract

Under geomagnetically quiet conditions there is a pronounced deficiency in energy deposition capable of ionizing the lower mesosphere and upper stratosphere. The precipitation of energetic outer radiation zone electrons can therefore provide the dominant ionization source at such altitudes, particularly during geomagnetically disturbed periods. The general importance of this energy input has already been stressed in the review talk by J. B. Reagen (1977). At relativistic energies (≳ 500 kev) the precipitating electrons deposit their energy near the base of the mesosphere; and the concomitant Bremsstrahlung X-rays provide additional energy deposition deep into the stratosphere.