Line-shape asymmetry of water vapor absorption lines in the 720-nm wavelength region

Measurements of H216O Linestrengths and Air-Induced Broadenings and Shifts in the 815-nm Spectral Region

“…These two profiles being symmetric, this asymmetry resides in the water vapor absorption line and reveals the presence of a statistical correlation between velocitychanging and state-perturbing collisions ( 23 ) . The use of a generalized Galatry function has been shown to resolve most of this discrepancy between the fit and the water vapor spectral data ( 30 ) .…”

Air- and N2-Broadening Parameters of Water Vapor: 604 to 2271 cm−1

“…They found the self-broadening coefficients in close agreement for both collision-narrowing models and when the data were analyzed with a Voigt profile; the corrections ranged from 17% at 20 Torr down to 6% at 50 Torr for a typical water line with a self-broadening coefficient equal to about 0.5 cm Ϫ1 /atm. In the second study (12), they applied the generalized Galatry (15) profile to the measurements which takes into account asymmetries in the lineshape and the fitted shapes were found to compare very well with the observed spectra. Valentin et al (16) reported N 2 -pressure-induced shifts of 109 lines between 1842 and 2212 cm Ϫ1 .…”

“…They (6) observed line narrowing (and increased absorption at the peak) for foreign gas pressures below 250 Torr and normal pressure-broadening effects above a few hundred Torr. Grossman and Browell (11,12) discussed these effects in detail and showed deviations resulting from line narrowing between measured profiles and the Voigt profile using tunabledye laser measurements of H 2 O self-broadening in the 13 558 -13 966 cm Ϫ1 region (11) and H 2 O broadened by xenon, argon, and oxygen in the same spectral region (12). They used the soft-collision model of Galatry (13) and the hard-collision model of Rautian and Sobel'man (14) to describe their observed line profiles.…”

N2-, O2-, and air-broadened half-widths, their temperature dependence, and line shifts for the rotation band of H216O

“…Some of these catalogues contain collisionalbroadening information based on the Voigt or Van-Vleck Weisskopf profile model. Often it is necessary to account for deviations from this model, such as collisional narrowing effects [10,11], and effects from velocity changing collisions [12][13][14][15][16], line-mixing as in H 2 O Raman Q-branch spectra [17][18][19], finite duration of collision effects in the far wings of the lines [20], atmospheric continua [21][22][23] and high pressure spectra [24].…”