The parameterization of energy fluxes (temperature, humidity) and trace gases such as CO2 and CH4 between the atmospheric boundary layer and the free troposphere is critical for modeling the long-range transport of these gases. The LMD has developed a mobile lidar observatory, integrating the TERA (Temperature, H2O Raman Lidar) and COWI (CO2 & Wind Lidar) instruments, capable of performing high spatiotemporal resolution measurements of wind speed, temperature, and humidity with sufficient precision to capture fluctuations related to atmospheric turbulence. Sensible and latent heat flux profiles obtained using the eddy-covariance method have enabled the first measurement of turbulent diffusion coefficients of scalars, particularly in the entrainment layer in temperate and semi-arid zones. This new type of observation has allowed for the testing of different local and non-local parameterizations of entrainment fluxes.

Contact : Fabien Gibert, gibert@lmd.polytechnique.fr
Link : Gibert, F., D. Edouart, P. Monnier, J. Collignan, J. Lopez, 2025 : Scalar turbulent fluxes and variances in the interfacial layer from lidar observations and assessment of Lagrangian Stochastic Models. Quarterly Journal of the Royal Meteorological Society, pp.e70016. (10.1002/qj.70016). (hal-05379361)