Specific distribution of the noise electromagnetic field level at high latitudes in the vicinity of the first Schumann resonance

Abstract

The distributions of the natural noise electromagnetic field level in the vicinity of the first Schumann resonance have been studied based on data from Lovozero observatory (the Kola Peninsula). Daily curves of noise level excesses over specified thresholds at different geomagnetic disturbances have been constructed. It has been indicated that the curves are morphologically similar on magnetically quiet days but are highly variable from day to day, although the averaged curves are similar in some characteristics to the unitary variation in the surface quasistatic electric field. The possibilities of applying the known formula for the probability distribution of the VLF atmospheric radio noise amplitude in order to analytically describe the noise level probability distribution have been considered. It has been detected that geomagnetic disturbances pronouncedly affect the distribution parameters, sharply increasing the amount of large-amplitude noise.