THE IMPACT OF PLANT STOMATAL CONTROL ON MESOSCALE ATMOSPHERIC CIRCULATIONS

Only a few numerical studies with mesoscale atmospheric models have been undertaken to explore the influence of vegetation on the generation and modification of mesoscale atmospheric circulations. Nevertheless, these few studies have demonstrated the importance of a correct representation of vegetation in the simulation of atmospheric features. In the present study, a mesoscale atmospheric model with a sophisticated land surface parameterization is used to emphasize the major role of plant stomata on the control of the Bowen ratio and on mesoscale atmospheric circulations. This study demonstrates that refinement of the land surface parameterization and stomatal mechanism, including subgrid-scale processes, is required in order to simulate confidently land-atmosphere interactions. This is particularly important when plants experience relatively strong stress and a small change in the stomatal behavior generates large variations in sensible and latent heat fluxes at the Earth's surface.