F-Layer Reflections and Ion Effects in the Propagation of Terrestrial ELF Waves

摘要

During nighttime waves penetrate above the D-layer and propagation parameters of the earth-to-ionosphere wave guide are dependent on the detailed ionospheric structure below the F-layer. The propagation characteristics are dependent on the altitude of the F-layer, electron density below this layer, the magnitude of the radial static magnetic field component, and also on ions that tend to increase the absorption of the penetrating magneto-ionic mode. The individual models advanced for the ionosphere are not representative of long distance or global wave propagation; but the average of the propagation parameters derived for a number of propagation geometries is comparable to the parameters deduced from an isotropic ionosphere model, where waves are confined to altitudes below 100 km. (Author)