Observed Seasonal Evolution of the Antarctic Slope Current System at the Coast of Dronning Maud Land, East Antarctica

The Antarctic Slope Front and the associated Antarctic Slope Current shield the continental shelves in East Antarctica from offshore warm water that holds the potential for considerable ice shelf melting and, consequently, sea level rise. Here, we present two-year-long records of temperature, salinity, and velocity (2019-2020), obtained from two oceanographic moorings located within the slope front/current over bathymetries of around 1000m and 2000m slightly east of the prime meridian. The two-year data record reveals clear differences in the seasonality of the thermocline depth and the baroclinicity of the current between the deep and shallow mooring locations. In combination with climatologies of hydrography and satellite-derived surface geostrophic currents, we use the new data to refine the baroclinic seasonality of the ASF. The results highlight the role of surface buoyancy fluxes via seasonal sea ice melt and freeze. Finally, the slope current is shown to control flow into and out of the cavity of the close-by Fimbulisen Ice Shelf on seasonal time scales depending on the orientation of the entrances of the cavity. Our findings contribute to a better understanding of the processes controlling the slope front/current seasonality and resulting inflow into the East-Antarctic ice shelf cavities.