Self-broadened line parameters for water vapour in the spectral region 5000–5600cm−1

Abstract

The self-broadening coefficients and intensities of approximately 460 of the strongest water vapour lines (intensity S ≥ 1.5x10-23 cm molec compilation, which revealed marked systematic differences in the self-broadening coefficients (up to 20%) and in the line intensities (up to 5%). The possible reasons for these deviations are discussed.

Fourier transform measurements of water vapor line parameters in the 4200–6600cm−1 region

“…Spectra under various conditions of path-length, pressure and in presence of air have been recorded to determine the positions, the intensities, the self-and air-broadening coefficients and the pressure-induced shifts of about 10,400 lines belonging to the four isotopologues Intensities have been measured for all observed lines, more than 30% of them being determined experimentally for the first time. For common sets of measurements, our intensity data agrees well on average with previous experimental works [21,22,[25][26][27]60,61] particularly for strong and medium lines. A detailed comparison with literature results has been done including the examination of the averaged A and R statistical criteria: the linear regression coefficient (A) and the median of intensity ratios distribution (R) that provide information on absolute intensity calibrations among various data sources.…”

“…4(a)-(d): the weakest lines are missing in panels (a) and (b) [22,60]; strong lines are missing in panels (b) and (c) [21,60]; and panel (d) only contains strong lines [61]. The number of previously measured intensities in this wave number range compared to our data (in %) is given in the second column of Table 10.…”

“…So, g self values vary from 0.0415 to 0.847 cm À1 /atm. Among these coefficients, 4466 belong to H 2 16 O intensities with the experimental (a-d) and calculated values found in the literature: (a) Toth [22], (b) Mikhailenko et al [19,60], (c) Macko et al [21], (d) Ptashnik et al [61], (e) Schwenke and Partridge [46]. The horizontal line is shown as a landmark.…”

“…9 illustrates this comparison for the common lines in the 011-00, 030-000 and 110-000 bands with DK a ¼ 0, 71 drawn vs. K m and J m as in [64]. Another set of values focusing on stronger lines in the restricted region 5000-5600 cm À1 [61] is also compared in the same figure. Their values are on average slightly lower than ours (mean ratio ¼ 1.04).…”

Laboratory measurements of the water vapor continuum in the 1200–8000 cm−1 region between 293 K and 351 K

“…In the 5000–5600 cm −1 region Ptashnik et al [2005] reported that HITRAN‐2004 systematically overestimates the self‐broadened half widths by up to 20% and intensities by up to 5%. Therefore in this region the measured intensities and self‐broadened half widths derived by Ptashnik et al are used in preference to those given in HITRAN‐2004.…”