DFG project Weddell sea ice

Model domain of the atmospheric model with 5km resolution with mean sea level pressure (isolines, only over ocean), mean 10m-wind field (vector wind every 6th grid point, scale in in m/s in the lower right) and directional constancy (shading) for March to August 2008. Contours over land show the elevation every 250 m.

In the southern Weddell Sea, the heat transfer of coastal polynyas to the atmosphere has strong effects on the atmospheric boundary layer, sea ice production and associated formation of High-Salinity Shelf Water (HSSW). The knowledge of polynya area, coverage of polynyas with thin ice, atmospheric forcing processes and oceanic processes is of high importance for the quantification of sea ice production and HSSW formation, which is a main driver of the ocean circulation and affects the basal melt rates at Filchner-Ronne Ice Shelf.

The overall goal of the project is the quantification of sea ice and HSSW production in the southern Weddell Sea for the last decade (2002-2012). As a novel approach, we will use a synergy of atmosphere/ocean/sea ice simulations and high-resolution sea ice thickness retrievals. The community climate model COSMO-CLM will be used as the atmospheric model, and the FESOM model of AWI as the sea-ice/ocean model. Thin-ice thicknesses retrievals from MODIS data will be used for independent ice production calculations and for the assimilation in FESOM. The outcome of the project will be an improved estimation of HSSW and ice production, and an error assessment of the different methods. This quantification of sea ice formation rates on the southern Weddell Sea continental shelf is not only important for questions related to oceanography and meteorology, but also affects the robustness of projections for the future of the Antarctic ice shelves and the Antarctic ice sheet.