OCS-CO2 line broadening coefficients and their temperature dependences for the Earth and Venus atmospheres

Abstract

Theoretical carbon dioxide broadened line widths of carbonyl sulfide molecule are reported at the room temperature for wide ranges of rotational quantum numbers (0 ≤ J ≤ 100) requested by spectroscopic databases. To get the temperature-dependence exponents, computations with the room-temperature parameters’ values are repeated for various temperatures characteristic of the Earth and Venus atmospheres. The calculations are performed by a semi-empirical method which is based on the impact theory of broadening, and includes the correction factors whose parameters can be determined by fitting the broadening or shifting coefficients to the experimental data. This approach particularly suitable for active molecules with nonzero dipole moments, which needs only a few experimental data for model parameters fitting. Since the common power law for the temperature-dependence exponents is invalid for wide temperature ranges, two separate sets of temperature exponents are provided for Earth and Venus atmospheres applications.