Semi-empirical calculation of air-broadened half-widths and air pressure-induced frequency shifts of water-vapor absorption lines
✍ Scribed by David Jacquemart; Robert Gamache; Laurence S. Rothman
- Publisher
- Elsevier Science
- Year
- 2005
- Tongue
- English
- Weight
- 818 KB
- Volume
- 96
- Category
- Article
- ISSN
- 0022-4073
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✦ Synopsis
This paper describes a semi-empirical calculation of the air-broadened half-widths and the air pressureinduced frequency shifts for the H 2 16 O isotopologue. This semi-empirical calculation is based on fits of several recent high-quality measurements and theoretical calculations to the first-order terms in the expansion of the complex Robert-Bonamy (CRB) equations, which yields a second-and first-order polynomial function of the differences in the upper-and lower-state vibrational quantum numbers for the half-width and line shift, respectively. The aim of this work was to obtain a complete set of air-broadened half-widths and air pressure-induced frequency shifts for transitions of H 2 16 O present in the HITRAN database from microwave to the visible in order to supplement the observed and calculated values. For around 700 sets of rotational quantum numbers (J 0 K 0 a K 0 c J 00 K 00 a K 00 c ), semi-empirical coefficients describing the vibrational dependence of the air-broadened half-widths and the air pressure-induced frequency shifts have been obtained directly from the fit of experimental and/or theoretical data. The accuracy of the parameters deduced from this calculation is estimated to be between 5% and 10% for the air-broadened half-widths and between 0.001 and 0:01 cm À1 atm À1 for the air pressure-induced frequency shifts. For sets of rotational quantum numbers for which either none or insufficient experimental/