New methods for the measurement of the diurnal variations in the parameters of natural ELF radio signals

Balser and Wagner (1960, 1962) have studied earth-ionosphere cavity resonances, taking into account diurnal power variations and their relationship to the world-wide thunder activity. The present paper is concerned with new methods for the recording of the temporal variations in the resonance frequencies, and the intensity of the fluctuations. These methods are characterized by the comparative simplicity of their technical implementation. Attention is given to fluctuations in the world-wide thunderstorm activity, the measurement of the variations in the resonance frequencies, and the determination of the values of ELF signal intensity and the peak frequencies.