Atmospheric Brightness Temperature Fluctuations in the Resonance Absorption Band of Water Vapor 1827.2 GHz

The results of processing new experimental data on descending radiation of atmosphere in the resonant band of water vapor absorption from 18 to 27.2 GHz are presented. The experiment was carried out using special multichannel microwave radiometer-spectrometer. Both summer and winter measurement periods for 2018-2019 are considered. When assessing the dynamics of brightness temperature fluctuations, the mathematical apparatus of structural functions is used. The frequency spectra of square root of structural function for various values of temporal interval are shown. Some experimental dependences of square root of structural function on air temperature and absolute humidity observed near the surface of the Earth under clear sky conditions are presented.