Influence of the Layered Structure of the Ionosphere on the Natural Elf Radiation Spectra

Abstract

This paper reports on some propagation effects occurring while the ionosphere consists of several layers. A few simple model problems were considered to show in which way this multi-layer structure can yield a new set of ELF resonance phenomena. The resonances appear in the space between the Earth and layer interfaces or inside the layers and are liable to give rise to peaks or minima in the frequency dependencies of ELF electromagnetic fields both for the cosmic and Earth sources. Calculations been made for the real ionosphere models and distant Earth's sources showed that such a mechanism can explain some experimental data including the effect of "The Evening Ionosphere Radiation" by Shecotov and Molchanov (Geomagnetism and Aeronomy,25,N4,598,1985).