CDSD-2024-PI: The update of the CDSD databank for the principal isotopologue of carbon dioxide

Abstract

The new room temperature ¹²C¹⁶O₂ line list (CDSD-2024-PI) is presented. This semi empirical line list contains the calculated line parameters (positions, intensities, air- and self-broadened half-widths, exponents of temperature dependence of air-broadened half-widths, and air pressure induced shifts). The reference temperature is 296 K, and intensity cutoff is 10^-30 cm^-1/(molecule cm^-2). More than 170,000 lines covering the 345 – 15383 cm^-1 spectral range are included in the line list. The line positions and intensities are based on the modeling within the framework of the method of effective operators. The air- and self-broadening coefficients were calculated using the empirical Padé approximations proposed in the works by Hashemi et al. [JQSRT 256, 107283 (2020)] and Tan et al. [ApJS 262:40 (2022)]. The air pressure induced line shift coefficients were calculated following the work by Hartmann [JQSRT 110, 2019 (2009)]. Compared to the ¹²C¹⁶O₂ line list of the CDSD-296 databank (Tashkun et al. [JQSRT 228, 124 (2019)]) this line list is extended to the higher wavenumber region and improved with the utilization of the new highly accurate experimental data for the fitting of the effective Hamiltonian and of the effective dipole moment parameters. CDSD-2024-PI is freely accessible via the Internet site of V.E. Zuev Institute of Atmospheric Optics SB RAS https://ftp.iao.ru/pub/LTS/CDSD-2024-PI/.