O 2A-band line parameters to support atmospheric remote sensing. Part II: The rare isotopologues

Abstract

Frequency-stabilized cavity ring-down spectroscopy (FS-CRDS) was employed to measure over 100 transitions in the R-branch of the b 1 Σ g + ← X 3 Σ g − (0,0) band for the rare O 2 isotopologues. The use of 17O- and 18O-enriched mixtures allowed for line positions to be measured for the 16O 17O, 16O 18O, 17O 2, 17O 18O, and 18O 2 isotopologues. Simultaneous fits to the upper and lower states were performed for each isotopologue using the FS-CRDS positions supplemented by microwave, millimeter, submillimeter, terahertz, and Raman ground state positions from the literature. Positions, line intensities, pressure broadening parameters, and collisional narrowing parameters are reported for the 16O 18O and 16O 17O isotopologues which are based upon the present study and our earlier FS-CRDS work (Long et al. J Quant Spectrosc Radiat Transfer 2010;111:2021 [18] and Robichaud et al. J Phys Chem A 2009;113:13089 [15]). The calculated line intensities include a term for the observed Herman–Wallis-like interaction and correct a frequency-dependent error, which is present in current spectroscopic databases.