Abstract. Current glacier melt rates in West Antarctica substantially exceed those around the East Antarctic margin. The exception is Wilkes Land where, e.g., Totten Glacier, underwent significant retreat between 2000 and 2012, underlining its sensitivity to climate change. This process is strongly influenced by ocean dynamics, which in turn changes in accordance with the evolution of the ice caps. Here, we present oceanographic data (temperature, salinity, density, dissolved oxygen) collected for the first time offshore the Sabrina Coast (East Antarctica), from the continental shelf break to ca 3000 m depth during austral summer 2017. The main water masses are identified by analysing thermohaline properties: the Antarctic Surface Water with θ > −1. 5 °C and S < 34.2 (σθ < 27.55 kg m−3), the Winter Water with −1.92 < θ < −1.75 °C and 34.0 < S < 34.5 (27.55 < σθ < 27.7 kg m−3), the modified Circumpolar Deep Water with θ > 0 °C and S > 34.5 (σθ > 27.7 kg m−3), and Antarctic Bottom Water with −0.50 < θ < 0 °C and 34.63 < S < 34.67 (27.83 < σθ < 27.85). The latter in this region is a mixture of dense waters originating from the Ross Sea and Adélie Land continental shelves, and is affected by the mixing process they undergo as they move westward along the Antarctic margin and interact with the locally formed dense waters, and with the warmer and saltier Circumpolar Deep Water. The spatial distribution of water masses offshore the Sabrina Coast also appears to be strongly linked with the complex morpho-bathymetry of the slope and rise area, supporting the hypothesis that downslope processes contribute to shaping the architecture of the distal portion of the continental margin.
The relative roles of modified circumpolar deep water and benthic sources in supplying iron to the recurrent phytoplankton blooms above Pennell and Mawson Banks, Ross Sea, Antarctica
