Coastal polynyas in the southwestern Weddell Sea: Surface fluxes, sea ice production and water mass modification

Abstract

Coastal polynyas in the southwestern Weddell Sea were simulated using the Finite Element Sea Ice-Ocean Model forced with NCEP/NCAR Reanalysis data. The period 1990-2009 was used in analysis. Also, shorter model runs forced with GME and COSMO model data were branched off and compared. Depending on the region, the 20-year mean winter heat flux to the atmosphere is 310-510 W/m^2, whereof 50-60 W/m^2 are supplied by cooling the ocean and the remainder induces a sea ice production of 7-13 cm/(d m^2). The coastal polynyas (0.6% of the area) contribute 11% to the southwestern Weddell Sea sea ice production. In the mean 2 Sv High Salinity Shelf Water are exported from the continental shelves. Different forcing data sets can cause substantial disparities in the regional results.