Journal of Quantative Spectroscopy and Radiative Transfer, 2024; https://doi.org/10.1016/j.jqsrt.2024.109026

É. Ducreux, B. Grouiez, S. Robert, M. Lepère, B. Vispoel, R.R. Gamache, L. Régalia

Abstract

H2O is an important molecule in the quest to better understand the evolution of solar system. In the study of Venus and Mars CO2-rich atmospheres (around 96 % of their composition) and because of the space instruments constant improvements, the planetary community needs spectroscopic data as accurate as possible.

Continuing from our previous study [JQSRT 231, 126(2019)], new spectra of H2O perturbed by CO2 were measured with our new experimental set-up in the 2.7 µm region to compare with the previous results. After the improvement in the determination of the partial pressure of water vapor, the line parameters were then determined with a multispectrum fitting procedure using a Voigt profile in the same way as in [JQSRT 231, 126(2019)]. This led to characteristic W-shape residuals that have been improved using beyond-Voigt profiles. Our investigation showed that considering the speed dependence of collisional line parameters is essential to obtain better line-shape parameters in the considered experimental conditions.