  Atmospherical mesoscale models can offer unique potentialities to
characterize and discriminate potential astronomical sites. Our team has
recently completely validated the Meso-Nh model above Dome C (Lascaux et al.
2009, 2010). Using all the measurements of CN2 profiles (15 nights) performed
so far at Dome C during the winter time (Trinquet et al. 2008) we proved that
the model can reconstruct, on rich statistical samples, reliable values of all
the three most important parameters characterizing the turbulence features of
an antarctic site: the surface layer thickness, the seeing in the free
atmosphere and in the surface layer. Using the same Meso-Nh model configuration
validated above Dome C, an extended study is now on-going for other sites above
the antarctic plateau, more precisely South Pole and Dome A. In this
contribution we present the most important results obtained in the model
validation process and the results obtained in the comparison between different
astronomical sites above the internal plateau. The Meso-Nh model confirms its
ability in discriminating between different optical turbulence behaviors, and
there is evidence that the three sites have different characteristics regarding
the seeing and the surface layer thickness. We highlight that this study
provides the first homogeneous estimate, done with comparable statistics, of
the optical turbulence developed in the whole 20-22 km above the ground at Dome
C, South Pole and Dome A.
