An energy source for the mid-latitude IAR: World thunderstorm centers, nearby discharges or neutral wind fluctuations?

Electromagnetic emissions from the world thunderstorm centers exist permanently and could be the energy source for the ionospheric Alfvén resonator (IAR) oscillations. We have calculated the power spectra for two horizontal components of the magnetic field at Karimshino station far from the world thunderstorm centers at the frequencies of IAR and Schumann Resonance and we have compared them with the spectra of the registered signals in the same frequency range. The spectra calculated within the model of three world thunderstorm centers and experimental spectra agree at the frequency of the first Schumann Resonance but they disagree severely at the IAR frequency range. The calculated power spectral density at Karimshino at 1 Hz is one–two orders less than the experimental one. This fact suggests that the spectral resonance structure is not simply due to stochastic lightning discharge process of tropical thunderstorms but that some other generation mechanisms are likely to exist.