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

Abstract

New high-resolution water vapor absorption spectra were obtained at room temperature in the 4200-6600 cm À1 spectral region by combining Fourier transform spectrometers (FTS) with single and multiple reflection cells. With absorption paths from 0.3 to 1800 m in pure and air diluted water vapor, accurate measurements of about 10400 lines in an intensity range from 10 À29 to 10 À19 cm/molecule have been performed. Positions, intensities, self-and air-broadening coefficients and air-induced shifts were determined for the H 2 16 O, H 2 17 O, H 2 18 O and HDO isotopologues. The rovibrational assignment of the observed lines was performed with the use of global variational predictions and allowed the identification of several new energy levels. One major contribution of this work consists of the identification of 3280 new weak lines. A very close agreement between the new measured parameters and those listed in the database is reported as well as between the observations and the most recent variational calculations for the positions and the intensities. The present parameters provide an extended and homogeneous data set for water vapor, which is shown to significantly improve the databases for atmospheric applications, especially in the transmission windows on both sides of the band centered at 5400 cm À1 .

Water vapour total columns from SCIAMACHY spectra in the 2.36 μm window

“…Later, new H 2 O line data published by Jenouvrier et al (2007) were substituted and CH 4 line air broadening data were taken from Predoi-Cross et al (2006) The most important issues complicating the retrieval are the increasing number of detector pixels affected by radiation damage (Kleipool et al, 2007) and the ice layer growing on the near-infrared detector windows (Gloudemans et al, , 2008. The detector pixels affected by radiation damage, causing higher noise levels or disfunctioning, must be excluded from the retrieval using a dynamic (observation time dependent) mask.…”

Water vapor isotopologue retrievals from high-resolution GOSAT shortwave infrared spectra

“…However, this error (typically around 20-100 ‰) is random and can be largely reduced by averaging in time and space. As for spectroscopy, we investigated the impact of using the official HITRAN database as well as the BXL database (Jenouvrier et al, 2007) and found a negligible impact on the retrieved variability in HDO/H 2 O abundances. Cross-correlations in retrieved HDO and H 2 O abundances are also negligible as the Jacobians for both are linearly independent (see Fig.…”

CH<sub>4</sub>, CO, and H<sub>2</sub>O spectroscopy for the Sentinel-5 Precursor mission: an assessment with the Total Carbon Column Observing Network measurements

“…For H 2 O in windows 1 to 4, we combined the line list by Jenouvrier et al (2007) with HITRAN08 by selecting for each absorption line the version that produced the smaller spectral fit residuals. For the TROPOMI range at 4190-4340 cm −1 , we used the line list developed by Scheepmaker et al (2012).…”

“…The surface pressure is measured at each TCCON station with a barometer (Wunch et al, 2011a). Dedicated effort in the past years to improve CH 4 and H 2 O spectroscopy in the 5880-6174 cm −1 range (Frankenberg et al, 2008;Tran et al, 2010;Jenouvrier et al, 2007) has enabled accurate retrieval of CH 4 columns from this spectral range. This has been confirmed by validation of GFIT retrievals with independent aircraft measurements.…”