The paper presents the results of simultaneous ground-based observations of gamma-ray spectra from soil radionuclides, volumetric radon activity, and electrical conductivity of the air in the surface atmosphere. Based on the analysis of gamma-ray spectra, the concentrations of U, Th and K in the upper soil layer and the terrestrial gamma-ray dose rate were estimated for 43 sites at 8 observation points, the distance between which ranges from 1 m to 25 km. The range of recorded concentrations was 1.28–2.64 mg/kg for K, 0.7–1.41 mg/kg for U, and 4.4–8.88 mg/kg for Th. The average ratios between the volumetric activities of the specified soil radionuclides and statistics of deviations from the averages were determined. During the observation period, the range of gamma-ray dose rate variation from soil radionuclides at a height of 1 m above the earths surface was 26–52 nGy/h. During the rain, an increase in the number of gamma-quanta in the Bi peaks is recorded, reaching 1200% for the quanta energy near 1765 keV and 300% for the quanta energy near 2204 keV. The autocorrelation function of the time series of gamma-ray dose rate from soil radionuclides in good weather conditions decreases with a characteristic time scale of several days, which decreases to several hours in the presence of precipitation in the analyzed time interval, accompanied by an increase in the Bi lines in the gamma-ray spectrum. The electrical conductivity of the air of the surface atmosphere shows the presence of a diurnal variation with a minimum in the daytime and two maxima — in the morning and evening. Observations distributed by height showed that the electrical conductivity at a height of 0.5 m is on average greater than at a height of 1.5 m, while in the daytime the difference in conductivity values at these heights is expressed more clearly.
S.V. Anisimov (Wed,) studied this question.