A preliminary study of the interaction between the snow surface layer and the boundary layer at Dome C (Antarctic plateau)

At DomeC, on the Antarctic plateau, several types of measurement provide in-situ observations to describe the characteristics of the surface and the boundary layer given by: a 45m tower with 6 levels of sensors measuring temperature, wind and humidity (Genthon et al, 2010), daily radio-sounding data, radiative fluxes (Lanconelli et al, 2011) and the temperature profile in the snow pack from the surface to 2m depth. Furthermore, the flatness of the site and the homogeneity of the surface, allow to have almost ideal conditions to use the 1D model for the study of the interaction between the surface and the boundary layer with a diurnal cycle amplitude about 18°C for a daily mean temperature around -30°C. The hypothesis of a low spatial variability around Dome C is quite realistic under certain conditions (E. Brun et al , 2011). The Limited Area Model AROME (Seity et al, 2011) has been compared to the in-situ observations and used to provide the forcing terms, like advection, for the 1D model. The ARPEGE analysis was used for the lateral boundary conditions and the initial state.

In the surface package (SURFEX) used in AROME, several snow schemes are available, in particular, a detailed multilayer snow model based on CROCUS validated during a 10 days period in January 2010 (E. Brun et al 2011). All those options gives us the opportunity to study the impact of the snow scheme and its interaction with the surface and the boundary layer.

To that purpose, several experiments will be carried out with the 1D model such as: using various snow schemes or using prescribed surface temperature or increasing the vertical resolution. Finally, the preliminary evaluations against the in-situ observations will be shown and some perspectives will be suggested.