Measurements of intensities and self-broadening line shape parameters of H2O absorption lines in the spectral range 700-2000 cm-1

Abstract

A Bruker IFS 125HR Fourier transform interferometer in combination with a multireflection cell was used to measure pure water vapor transmission spectra in the range 700-2000 cm-1. A total of 17 spectra with absorption path lengths between 14 m and 161 m and sample gas pressures from 0.01 to 20 mbar were measured at room temperature. The recorded spectra were corrected for detector non-linearity, thermal self-radiation and for deviations from an ideal instrumental line shape. A multispectrum-fitting approach was used, applying a quadratic speed-dependent Voigt line model which was extended to account for Rosenkranz line mixing. Experimentally determined line shape parameters are compared to the HITRAN database. Line intensities are also compared to values from two ab initio calculations [1][2]. The overall agreement with both is better than 0.5% for most lines. [1] L. Lodi, J. Tennyson, O. L. Polyansky, The journal of chemical physics, 2011, 135(3), 034113 [2] E. K. Conway, I. E. Gordon, A. A. Kyuberis, O. L. Polyansky, J. Tennyson, N. F. Zobov, Journal of Qualitative Spectroscopy and Radiative Transfer, 2020, 241, 106711