Analysis of the He-, Ar- and Kr-broadening coefficients of water vapor transitions in a wide spectral region

Abstract An analysis of the measured He-, Ar- and Kr- broadening coefficients γ for 1575 water vapor transitions of 27 vibrational bands belonging to the 0.6–11200 cm–1 spectral region is performed using an empirical function that contains adjustable parameters. An universal function is detected during the analysis. This function depends on the parameters that are common for all perturbers A=(He, Ar or Kr). A universal function multiplied by one additional parameter x20(A) determines the broadening coefficients γ(A) for each perturber A = (He, Ar or Kr).Two fitting procedures are used. The first considers the fit of measured γ(exp) for individual rotational branches while the other considers the global fit of all 1575 measured γ(exp). In the second procedure, ratios of γ(Kr) / γ(He) = 2.543±0.040 and γ(Kr) / γ(Ar) = 1.252±0.036 are found. The coefficients derived from the fitted parameters are compared statistically to measured coefficients.