Two-micrometer heterodyne differential absorption lidar measurements of the atmospheric CO₂ mixing ratio in the boundary layer

Fabien Gibert (1) , Pierre H. Flamant (1) , Didier Bruneau (2) , Claude Loth (1)

1 LMD - Laboratoire de Météorologie Dynamique (UMR 8539)
2 SA - Service d'aéronomie

A 2 μm heterodyne differential absorption lidar (HDIAL) has been operated at the Instïtut Pierre Simon Laplace, Laboratoire de Météorologie Dynamique (Paris) to monitor the CO₂ mixing ratio in absolute value at high accuracy in the atmospheric boundary layer. Horizontal measurements at increasing range are made to retrieve the optical depth. The experimental setup takes advantage of a heterodyne lidar developed for wind velocity measurements. A control unit based on a photoacoustic cell filled with CO₂ is tested to correct afterward for ON-line frequency drift. The HDIAL results are validated using in situ routine measurements. The Doppler capability is used to follow the change in wind direction in the Paris suburbs.

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

Fabien Gibert, Pierre H. Flamant, Didier Bruneau, Claude Loth. Two-micrometer heterodyne differential absorption lidar measurements of the atmospheric CO₂ mixing ratio in the boundary layer. Applied optics, 2006, 45 (18), pp.4448-4458. ⟨10.1364/AO.45.004448⟩. ⟨hal-00093980⟩