Nature of the Increase in the Gamma Flux Observed during Precipitation: The Radionuclide Hypothesis Is not Supported

New experiments are performed using a gamma ray spectrometer installed at the cosmic ray station in Apatity. The spectrometer monitors the differential spectrum of gamma radiation coming from the atmosphere in the 0.1–4 MeV range of energies. Analysis of the gamma radiation spectra in dozens of increases shows that the effect of growing gamma radiation during precipitation is not related to the presence of radionuclides, or the additional release of radionuclides from the soil. The characteristics of the gamma ray spectra indicate meteorological processes in the atmosphere as the primary cause of the increase effect.