Laser diode absorption spectroscopy for accurate CO₂ line parameters at 2 μm: consequences for space-based DIAL measurements and potential biases

Lilian Joly (1) , Fabien Marnas (2) , Fabien Gibert (2) , Didier Bruneau (3) , Bruno Grouiez (1) , Pierre H. Flamant (2) , Georges Durry (1) , Nicolas Dumelie (1) , Bertrand Parvitte (1) , Virginie Zéninari (1)

1 GSMA - Groupe de spectrométrie moléculaire et atmosphérique
2 LMD - Laboratoire de Météorologie Dynamique (UMR 8539)
3 TROPO - LATMOS

Space-based active sensing of CO₂ concentration is a very promising technique for the derivation of CO₂ surface fluxes. There is a need for accurate spectroscopic parameters to enable accurate space-based measurements to address global climatic issues. New spectroscopic measurements using laser diode absorption spectroscopy are presented for the preselected R30 CO₂ absorption line ((20⁰1)_III←(000) band) and four others. The line strength, air-broadening halfwidth, and its temperature dependence have been investigated. The results exhibit significant improvement for the R30 CO₂ absorption line: 0.4% on the line strength, 0.15% on the air-broadening coefficient, and 0.45% on its temperature dependence. Analysis of potential biases of space-based DIAL CO₂ mixing ratio measurements associated to spectroscopic parameter uncertainties are presented.

Mots clés: Remote sensing; DIAL; Differential absorption lidar; Spectroscopy; Diode lasers

Domaines: Physique Atmosphérique et Océanique [physics.ao-ph]

Lilian Joly, Fabien Marnas, Fabien Gibert, Didier Bruneau, Bruno Grouiez, et al.. Laser diode absorption spectroscopy for accurate CO₂ line parameters at 2 μm: consequences for space-based DIAL measurements and potential biases. Applied optics, 2009, 48 (29), pp.5475-5483. ⟨10.1364/AO.48.005475⟩. ⟨hal-00429159⟩