Analysis of the variability of natural gamma radiation during intense atmospheric electric field events.

Abstract:

Natural gamma radiation (γ) is produced mainly during the interaction of energetic cosmic rays in the Earth’s atmosphere, in the decay of radionuclides in the soil, and during transient energetic atmospheric phenomena. The γ variability and its correlation with the atmospheric electric field is important for better understanding phenomena like thunderstorms and lightning. This paper aims to analyze high increases of gamma radiation during intense atmospheric electric field events (e.g., thunderstorms). The data were obtained from the Complejo Astronomico El Leoncito in San Juan, Argentina from April 2018 to February 2019. In disturbed weather conditions, we generally found increases in γ associated with intense atmospheric electric field variation and/or rain precipitation. Thirteen events of impulsive increases of γ were observed. Ten were associated with the occurrence of thunderstorms and rain precipitation and three were associated only with thunderstorms. The most significant increase in γ (35%) was detected when there was thunderstorm and rain precipitation occurring at the same time. A significant linear correlation was observed between atmospheric electric field intensities and γ (R=0.85) as well as between the rainfall rate and γ (R=0.79).