High sensitivity CW-cavity ring down spectroscopy of 12CO 2 near 1.35 μm (II): New observations and line intensities modeling

Abstract

In a previous contribution [Kassi S, Song KF, Campargue A. High sensitivity CW-cavity ring down spectroscopy of 12CO 2 near 1.35 μm (I): line positions. JQSRT 110 (2009) 1801–1814], the line positions analysis of the high sensitivity absorption spectrum of carbon dioxide has been reported in the 7123–7793 cm −1 region. In this second contribution, the spectral region investigated by CW-cavity ring down spectroscopy has been extended up to 7917 cm −1. It added about 400 lines to our previous list of about 2500 transitions. These additional lines include transitions belonging to six newly observed 12C 16O 2 bands for which we provide the spectroscopic parameters. Over the whole 7123–7917 cm −1 region, the accurate intensities of about 2900 lines belonging to four isotopologues ( 12C 16O 2, 13C 16O 2, 16O 12C 18O and 16O 12C 17O) were retrieved with an average accuracy of 3%. Intensity values range between 1.2×10 −29 and 4.1×10 −25 cm/mol. Compared to the present version of the carbon dioxide spectroscopic databank recently adopted for the HITRAN database, important deviations were evidenced for some weak bands of the main isotopologue. The CW-CRDS intensity data relative to a total of 46 12C 16O 2 bands together with selected intensity information available in the literature for nine bands have been fitted simultaneously using the effective operators approach. The Δ P=11 set of the 12C 16O 2 effective dipole moment parameters has been refined leading to a much better agreement with the measured intensity values. In addition, the Δ P=10 effective dipole moment parameters of the 16O 12C 18O minor isotopologue were determined for the first time. The obtained results will help to improve the carbon dioxide spectroscopic databank (CDSD).