Preliminary Results of Searches for Long-Term Microwave Radiation of a Thunderstorm Atmosphere at a Wavelength of 1.35 cm

Measurement of non-thermal radiation is currently one of the directions of remote sensing of the Earth. Powerful electromagnetic radiation of the atmosphere, initiated by cosmic rays, in the range from low frequencies to the gamma range, has recently been discovered here. Of particular interest is the study of such radiation in the microwave range, where the technique of aerospace research is well developed. This paper presents the results of joint measurements of microwave and gamma radiation of the atmosphere during thunderstorms in the summer of 2022 in Transbaikalia. The aim of the study was to search for relatively long (up to several minutes) electromagnetic radiation near the frequency of 22.2 GHz on the line of the rotational spectrum of water vapor molecules. It was assumed that such a feature could arise due to the appearance of avalanches of escaping electrons generated by cosmic rays. In this process, in addition to the braking gamma radiation, the gas medium is excited, which can cause its superradiance in the microwave range. In the case of strong electrification in fields with a voltage above 0.284 MV/m, a unique phenomenon may occur - a self-sustaining photonuclear reaction in the lower atmosphere in thunderclouds. In this process, the electromagnetic glow can last from units to tens of minutes. In the performed study, several episodes of increasing radiation intensity in the microwave range were detected, accompanied by gamma-ray pulses in a thunderstorm atmosphere. The glow detected in the experiment can be explained by local electrical discharges with increasing electrification of clouds. Another explanation is the occurrence of a self-sustaining photonuclear reaction that creates a large volume of excited gas. The ways of improving the microwave measurement technique for recording high-energy phenomena in the lower atmosphere at a great distance from the measuring equipment, where gamma rays are not recorded, using the satellite are discussed.