Measurements of air-broadening parameters of water vapour transitions in the 7520–8586 cm⁻¹ spectral region

Abstract

The water vapour line broadening (γ) and shift (δ) coefficients for 319 lines of 11 vibrational bands 2ν₃, 2ν₂ +ν₃, 3ν₂+ν₃, 5ν₂, 6ν₂, ν₁+ν₃, ν₁+ν₂+ν₃, ν₁+2ν₂, ν₁+3ν₂, 2ν₁, and 2ν₁+ν₂ from the spectral region 7520–8586 cm^–1 induced by air pressure were measured with a Bruker IFS 125 spectrometer. The measurements were performed at a spectral resolution of 0.01 cm^–1 and over a wide air pressure range. The calculations of the line-shift coefficients δ were performed in the framework of a semi-classical method. The measured air-broadening coefficients γ were combined with literature data for air- and N₂-broadening coefficients γ measured for the lines in the 380–22,593 cm^–1 spectral region. Combined experimental data for N = 4110 measured coefficients γ of 76 vibrational bands of H₂O molecules were fitted to the empirical functions. The computed coefficients γ derived from the fitted parameters were statistically compared with the measurements. The vibrational dependence of the measured γ values and their compatibility is discussed.

GRAPHICAL ABSTRACT

KEYWORDS:

• H₂O
• analysis
• broadening and shift coefficients

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by RFBR and Tomsk region administration (project number 18-45-700011 r_a) and from the Ministry of Science and Higher Education of the Russian Federation (budget funds for IOA SB RAS).