ИСТИНА

Schumann resonance power spectra excited by individual lightning discharges and by stochastic lightning discharges due to global thunderstorm activity are theoretically estimated both in the Earth-ionosphere waveguide and at the ionospheric altitudes. Thr dependence of resonance spectra on the daytime and nighttime ionospheric parameters and the inclination angle of geomagnetic field lines are investigated. The magnitudes of the ELF/ULF electric and magnetic power spectra at the ionosperic altitudes are shown to be strongly smaller than that at the ground surface especially at the daytime. The two opposite cases of polar and equatorial ionosphere are examined. The middle latitude region appears to be more favorable for onboard observation of the Schumann resonances. Results of our calculation were compared with power spectra recorded at the C/NOFS satellite. The theoretucal possibility of Schumann resonance observation at the low orbiting satellites is indicated.