Shifting temperature dependence of nitrogen-broadened lines in the ν 2 band of H2O

Abstract

We report the nitrogen-induced shifting coefficients of 37 water vapour rovibrational transitions in the 1845–2140 cm−1 spectral region. The measurements were made with a Fourier transform spectrometer at Paris University in the 258–330 K temperature range at a spectral resolution of 0.005 cm−1 for lines with low state rotational quantum number up to 14. The measured exponents of the temperature dependence of the width exhibit a large range of values from 0 to 2.5. Theoretical calculations are based on impact theory modified by introducing additional parameters to extend the use of empirical data. The model parameters are determined by fitting the broadening and shifting coefficients to experimental data. The calculated line shift coefficients as well as the temperature exponents for the line shift agree satisfactorily with measured values.