Daily and Seasonal Variations of Soft Gamma Radiation in the Lower Atmosphere

Soft gamma radiation that appears in the atmosphere as part of secondary cosmic rays has so far been studied very poorly. Observations with a gamma-ray detector designed at the Polar Geophysical Institute began in 2010 at cosmic-ray stations in Apatity and Barentsburg (in the Spitsbergen Archipelago). Observations are now being made at six stations. Two types of variation, annual and daily, are reliably observed in the data obtained with the detectors. The annual variation is associated with the formation of a stable snow cover during the cold season. The daily variation has a specific feature: the positions of its maximum and minimum differ from the analogous quantities in neutron monitors and muon detectors.