Absorption of deuterated water vapor in the 1.98 µm spectral region

New spectra of water samples enriched by deuterium were recorded between 4500 and 5800 cm−1 using a Fourier transform spectrometer Bruker IFS 125HR combined to multi-pass cells. The spectra were recorded at room temperature with a non apodized resolution of 0.01 cm−1, using water evaporated from a D2O+H2O mixture in the liquid phase. The water vapor pressure was about 1.5 Torr and the absorption path was more than 100 m. A special attention was paid to the experimental procedure allowing to obtain HDO in the gas phase, and also to determine the partial pressure of all isotopologues. Synthetic spectra were compared to the observed ones. Numerous examples of disagreements between measurements and simulations using existing water line lists were observed for deuterated water species. Some lacks were found in the HITRAN2016 line list. A list of 580 transitions is reported that corrects erroneous and missing lines. © 2021Agence Nationale de la Recherche, ANR, (ANR-16-CE01-0009)Russian Science Foundation, RSF, (18-11-00024-Π)This work was partially funded through WaVIL project funded by Agence Nationale de la Recherche , grant no. ANR-16-CE01-0009 . The author would like to thank Dr. Cyrille Flamant. SM activity was supported in the frame of the Russian Science Foundation , grant no. 18-11-00024-Π

Line parameters of water vapor enriched by 18O from 6525 to 8011 cm−1

This study is a continuation of experimental efforts on the analysis of the near-infrared absorption spectrum of water vapor. Our previous studies were focused on water vapor in natural isotopic abundance. Now we are interested in the H2 18O water isotopologue. New spectra of water samples enriched by 18O were recorded between 6400 and 9400 cm−1 in Reims with the Connes-type Fourier Transform Spectrometer, built in our laboratory. The spectra were recorded at room temperature with a H2 18O abundance enrichment of about 95% and a non apodized resolution of 0.010 cm−1. Pressure varied from 2 to 13 torr and the absorption path length was from 67 cm to 1001 m. This article presents the results of the analysis of the first part of the whole recorded spectral range below 8000 cm−1. About 8100 absorption lines were found in the recorded spectra with an absorption path length from 8 to 88 m between 6525 and 8011 cm−1. Overall, 7993 lines were assigned to 8647 transitions of six water isotopologues (H2 16O, H2 17O, H2 18O, HD16O, HD17O, and HD18O). Ninety-eight lines with intensity values between 6 × 10−27 and 1.45 × 10−25 cm/molecule were left unassigned. More than 870 H2 18O, H2 17O and HD18O lines were observed for the first time. The observed line positions allow to obtain about 90 new or corrected rotation-vibration energy levels of H2 18O and H2 17O. Comparison of line positions and intensities with literature data are presented and discussed. Some examples of disagreements between the measurements and data from the literature are presented in the last part of this article. © 2019 Elsevier Lt

CO2 line-mixing database and software update and its tests in the 2.1μm and 4.3μm regions

An update of the former version of the database and software for the calculation of CO2-air absorption coefficients taking line-mixing into account [Lamouroux et al. J Quant Spectrosc Radiat Transf 2010;111:2321] is described. In this new edition, the data sets were constructed using parameters from the 2012 version of the HITRAN database and recent measurements of line-shape parameters. Among other improvements, speed-dependent profiles can now be used if line-mixing is treated within the first order approximation. This new package is tested using laboratory spectra measured in the 2.1μm and 4.3μm spectral regions for various pressures, temperatures and CO2 concentration conditions. Despite improvements at 4.3μm at room temperature, the conclusions on the quality of this update are more ambiguous at low temperature and in the 2.1μm region. Further tests using laboratory and atmospheric spectra are thus required for the evaluation of the performances of this updated package.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Line intensities of acetylene in the 3-µm region : new measurements of weak hot bands and global fitting.” J.

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