New transitions and energy levels of water vapor by high sensitivity CRDS near 1.73 and 1.54 µm. (October 2019)

• Record Type: Journal Article
• Authors: Mikhailenko, S.N.; Karlovets, E.V.; Vasilchenko, S.; Mondelain, D.; Kassi, S.; Campargue, A.
• Is Part Of: Journal of quantitative spectroscopy & radiative transfer. Volume 238(2019)
• Publication Date: 2019-10
• Subjects: Cavity ring down spectroscopy -- Water -- H217O -- HD17O -- Rovibrational assignments -- HITRAN -- Isotopologue; Spectrum analysis -- Periodicals; Radiation -- Periodicals; Analyse spectrale -- Périodiques; Rayonnement -- Périodiques; Radiation; Spectrum analysis; Periodicals; 543.0858
• DOI: 10.1016/j.jqsrt.2019.106574
• Languages: English
• ISSNs: 0022-4073

Abstract

Highlights: CRDS of natural water vapor between 5693 and 5991 cm −1 and highly 17 O enriched water between 6223 and 6672 cm −1 . 1452 water lines are assigned to 1573 transitions in the natural water spectrum, 251 lines are measured for the first time. Thirty eight new energy levels are determined. Deviations compared to the HITRAN database and to the IUPAC-TG energy levels are discussed. Abstract: This contribution is part of a long term project aiming at improving the water absorption spectroscopy by high sensitivity cavity ring down spectroscopy (CRDS) in the near infrared. Two new sources of CRDS spectra are considered: (i) The room temperature absorption spectrum of water vapor in natural isotopic abundance is recorded near 1.73 µm. A series of recordings was performed from 5693 to 5991 cm −1 with a pressure value of about 6 Torr. The noise equivalent absorption (α min ) of the spectra is better than 10 − 10 cm −1 . A total of 1453 lines were assigned to 1573 transitions of four water isotopologues (H2 16 O, H2 17 O, H2 18 O and HD 16 O). Their intensities span more than five orders of magnitude from 3.0 × 10 −30 to 4.7 × 10 −25 cm/molecule at 296 K. The assignments were performed using known experimental energy levels as well as calculated line lists based on the results of Schwenke and Partridge. Two hundred fifty-one lines (assigned to 280 transitions) are observed for the first time and twelve energy levels are newly determined. The comparison of the obtained line parameters with those of the HITRAN database is discussed. Forty-six line positions are observed to significantly differ from their HITRAN values ( δν = │ ν HITRAN – ν CRDS │ > 0.02 cm −1 ). The derived set of energy levels is compared to those recommended by an IUPAC task group. (ii) The room temperature CRDS spectrum of water vapor highly enriched in 17 O was recorded near 1.54 µm (6223–6672 cm −1 ) at a pressure of 12 Torr. Compared to a previous study, the higher pressure of the recordings allowed for extending the observations. Overall, twenty-six new levels were determined for both H2 17 O and HD 17 O. All these observations together with other recent measurements will allow for an extension and an update of our empirical database in the 5693– 8340 cm −1 region. Graphical abstract: Image, graphical abstract