Resonator spectroscopy of the atmosphere in the 350–500 GHz range

Results of studies of the absorption spectra of laboratory air and major atmospheric gases mixed with water vapor in the 350–500 GHz frequency range at atmospheric pressure and room temperature are presented. The spectra were registered for the first time by highly sensitive microwave method employing the resonator spectrometer. Analysis of the spectra allowed determining integrated intensities and values of nitrogen, oxygen and air pressure shift and broadening of the most intense lines of H2O and O2 molecules within this range. Some parameters were measured for the first time. The values of parameters were compared with results of earlier measurements and calculations. In addition, a complementary investigation of collisional parameters of the most intense water lines within the considered range by means of the spectrometer with radioacoustic absorption detection at low pressure was performed. Data of these measurements agree with results of analysis of atmospheric spectra within statistical accuracy of both experiments. The research made is important, in particular, for enhancing accuracy of models of radiation propagation in the atmosphere. -- Highlights: ► Atmospheric spectra in 350–500 GHz range are recorded for the first time by microwave method. ► Supplementary measurements at low pressure are performed. ► Refined values of water and oxygen molecular line parameters are obtained. ► Obtained data are of importance for the atmosphere remote sensing.