Collision-induced absorptions by pure CO₂ in the infrared: New measurements in the 1150–4500 cm⁻¹ spectral range and empirical modeling for applications

Knowledge of collision-induced absorptions (CIA) by pure CO₂ for wide temperature ranges is necessary for atmospheric and climate studies of planets and exoplanets with CO₂-rich atmospheres. In this work, using spectra measured with a Fourier transform spectrometer for temperatures between 230 K and 295 K at pressures up to 40 bar, several CIA bands in the 1150–4500 cm⁻¹ spectral range have been determined, in some cases for the first time. The results are compared with values reported in the literature, showing good agreements. From data obtained in this work and those in the literature, we propose simple analytical models for the temperature dependent band shape and integrated band intensity (IBI) which enable the calculation of all investigated CIA transitions in a wide temperature range.