Séminaire
The forcing of convection by its environment is a topic of great importance for global weather and climate models. Many tropical phenomena such as the Madden-Julian oscillation and various tropical wave modes are highly sensitive to the treatment of convection. Using observational, theoretical, and modeling tools, we have developed a framework for the thermodynamic aspects of this forcing. The thermodynamic predictive variables are the sur-
face moist entropy flux, the saturation fraction, and a measure of low to middle level moist convective instability. This scheme works well in regions of near-uniform sea surface temperature. However, strong SST gradients are likely to require a fourth variable, deep convective inhibition. The upcoming OTREC (organization of tropical east Pacific convection) project should yield insight into the strong SST gradient case.
marie-pierre.lefebvre@lmd.jussieu.fr