Importance de la paramétrisation hydrodynamique des premiers centimètres du sol pour la modélisation des flux de surface en Afrique de l'ouest (Importance of topsoil hydrodynamic parameterization for modeling land surface fluxes in West Africa)

Simon Gascoin (1, 2)

1 CESBIO - Centre d'études spatiales de la biosphère
2 SISYPHE - Structure et fonctionnement des systèmes hydriques continentaux

Land-atmosphere coupling is critical to understand climate variability in West Africa, including the Sahel drought. Among land surface processes, hydrological processes play a major role. In the Sahel water fluxes are controlled by the soil surface layer properties. Using a land surface model we show that it is possible to improve the energy partitioning between latent and sensible heat fluxes by decreasing the water exchanges through the soil surface layer. A sensitivity test reveals that such a calibration would strongly modify the energy budget of West African surface as calculated by the default parameterization, in particular in the Sahel region where the bare soil fraction is large, which demonstrates the importance of topsoil hydrodynamic for climate modeling in this region.

Domaines: Hydrologie; Interfaces continentales, environnement; Milieux et Changements globaux

Simon Gascoin. Importance de la paramétrisation hydrodynamique des premiers centimètres du sol pour la modélisation des flux de surface en Afrique de l'ouest (Importance of topsoil hydrodynamic parameterization for modeling land surface fluxes in West Africa). La Houille Blanche - Revue internationale de l'eau, 2010, pp.87-90. ⟨10.1051/LHB/2010059⟩. ⟨hal-00651089⟩