Process-Level Evaluation of the Land-Atmosphere Interactions Within CNRM-CM6-1 Single-Column Model Configuration
Évaluation au niveau des processus des interactions sol-atmosphère dans la configuration du modèle à une seule colonne CNRM-CM6-1
Bernard, Emilie ; Roehrig, Romain ; Couvreux, Fleur ; Canut, Guylaine ; Delire, Christine ; Lohou, Fabienne ; Lothon, Marie ; Decharme, Bertrand
Année de publication
2025
Land-atmosphere coupling involves multiple processes occurring across different temporal and spatial scales. These complex processes are not yet fully represented in climate or numerical weather prediction models. To evaluate these coupled models and improve or develop new parameterizations, four different single-column model setups are proposed. These setups vary in the type of spatially homogeneous land cover: grassland, wheat field, corn field, and pine forest. They are based on the single-column version of the CNRM-CM6-1 model, which couples the ARPEGE-Climat atmospheric component with the SURFEX surface modeling platform. First, the simulation results are compared with observational data, focusing on the radiative balance, surface fluxes, soil temperature and moisture, as well as air temperature, specific humidity, and wind speed near the surface. The evaluation shows that the ARPEGE-SURFEX single-column model can accurately replicate both surface and atmospheric conditions. Next, the same modeling framework is applied to the Meso-NH-SURFEX large-eddy simulation model. These simulations provide a consistent reference for evaluating the boundary-layer in CNRM-CM6-1, particularly in terms of potential temperature and specific humidity throughout the day. Finally, a sensitivity study on the impact of surface parameters on land-atmosphere coupling reveals that the hydric stress parameterization, by modifying canopy conductance and transpiration, is the most influential driver of temperature and moisture in the mixed layer. This work highlights the advantages of using the ARPEGE-SURFEX single-column configuration as a reliable platform for experimentation and parameterization improvement, and local climate modeling. The study cases developed are made available for further evaluation of land-atmosphere coupling.</div>
Texte intégral
Accès à la notice sur le site du portail documentaire de Météo-France