Studies on non-linear heating of the lower ionosphere during interaction between HF and ELF signals

Abstract

Non-linear interaction between Schumann resonances (SR) and high frequency round-the-world signals (RWS) in the lower ionosphere yields the ELF spectra that correspond to the three first modes of Schumann resonances. The phenomenon resembles Luxembourg effect between Schumann resonances and HF signals. The intensity of natural electromagnetic field

(SR field) produced by thunderstorm activity is strong enough to give rise to non-linear effects in the D-layer. As a result, there will be heating of electrons by the ELF oscillations of SR fields (<i>E</i>_s). The fair-weather electric field (<i>E</i>₀) also initiates the process of heating in the D-layer. The influence of this field gives a linear dependence of electron temperature fluctuations on the field strength on SR. These lead to non-linear effects comprising the variations of electron temperature, effective collision frequency and conductivity of the medium. Also, there will be modulation of HF waves by ELF signals.