High-resolution spectroscopy and global analysis of CF4 rovibrational bands to model its atmospheric absorption

M. Carlos (1, 2) , O. Gruson (1) , C. Richard (1) , V. Boudon (1) , M. Rotger (3) , X. Thomas (3) , C. Maul (4) , C. Sydow (4) , A. Domanskaya (5) , Robert Georges (6) , P. Soulard (7) , O. Pirali (8, 9) , M. Goubet (10) , P. Asselin (7) , T. R. Huet (10)

1 ICB - Laboratoire Interdisciplinaire Carnot de Bourgogne
2 IRAP - Institut de recherche en astrophysique et planétologie
3 GSMA - Groupe de spectrométrie moléculaire et atmosphérique
4 Technische Universität Braunschweig = Technical University of Braunschweig [Braunschweig]
5 SPbU - St Petersburg State University
6 IPR - Institut de Physique de Rennes
7 MONARIS - De la Molécule aux Nanos-objets : Réactivité, Interactions et Spectroscopies
8 ISMO - Institut des Sciences Moléculaires d'Orsay
9 SSOLEIL - Synchrotron SOLEIL
10 PhLAM - Laboratoire de Physique des Lasers, Atomes et Molécules - UMR 8523

CF4, or tetrafluoromethane, is a chemically inert and strongly absorbing greenhouse gas, mainly of anthropogenic origin. In order to monitor and reduce its atmospheric emissions and concentration, it is thus necessary to obtain an accurate model of its infrared absorption. Such models allow opacity calculations for radiative transfer atmospheric models. In the present work, we perform a global analysis (divided into two distinct fitting schemes) of 17 rovibrational bands of CF4. This gives a reliable model of many of its lower rovibrational levels and allows the calculation of the infrared absorption in the strongly absorbing ν3 region (1283 cm−1 / 7.8 μm), including the main hot band, namely ν3+ν2−ν2 as well as ν3+ν1−ν1; we could also extrapolate the ν3+ν4−ν4 absorption. This represents almost 92% of the absorption at room temperature in this spectral region. A new accurate value of the C–F bond length is evaluated to re=1.314860(21)Å. The present results have been used to update the HITRAN, GEISA and TFMeCaSDa (VAMDC) databases.

Mots clés: Tensorial Formalism; Spherical Top; Line Positions and Intensities; Carbon tetrafluoride; Fourrier Transform Infrared Spectroscopy; Global fit; Molecular physics

Domaines: Physique [physics]; Physique Atomique [physics.atom-ph]

M. Carlos, O. Gruson, C. Richard, V. Boudon, M. Rotger, et al.. High-resolution spectroscopy and global analysis of CF4 rovibrational bands to model its atmospheric absorption. Journal of Quantitative Spectroscopy and Radiative Transfer, 2017, 201, pp.75-93. ⟨10.1016/j.jqsrt.2017.06.039⟩. ⟨hal-01580453⟩