Numerical modelling of the circulation of superrotating atmospheres: Venus and Titan

Atmospheric superrotation has been known for decades on Venus where the cloud cover, at 70 km above the surface, rotates about 60 times faster than the solid planet. Superrotation is also strongly suspected on Titan on the basis of both numerical studies and observations. We show how general circulation models, originally developed for terrestrial meteorology and climatology, can be used to infer the circulation in such atmospheres. We focus on the case of Titan for which a specific GCM has been developed at LMD in the last few years.