6 Mar 2026
Alexander Haumann and Rowan Brown (SO-KLIM) are currently on a research expedition in the western Weddell Sea (Antarctica). They are investigating sea ice melt and water mixing processes, which are central to ocean circulation, carbon and heat fluxes.
The Summer Weddell Outflow Study (SWOS), led by the Alfred-Wegener Institute for Polar and Marine Research (AWI) started on 6 February 2026 and will run until 11 April 2026. Alexander Haumann and Rowan Brown from the SO-CLIM research group are part of this international research effort. They will mainly study how the melting of sea ice is affected by the ocean, and the role of mixing of water masses in controlling heat and freshwater fluxes of the western Weddell Sea—an area that has been poorly observed and understood until now, largely due to challenges to access this region.
On board the research vessel Polarstern scientists focus on a broad range of processes, from sea ice processes to ice-ocean and ice-atmosphere interactions, ecosystem parameters, and classical and novel oceanographic measurements. A particular focus of our group is to measure mixing of water underneath sea ice that induce a flux of warmer water towards the ice and potentially melts it. For this purpose, we deploy a set of instruments through holes in the ice to measure heat fluxes and take water samples for later isotope analysis that will enable a tracing of sea ice meltwater in the ocean.
The start to the expedition included several challenges in getting to RV Polarstern that was waiting for the participants in Punta Arenas. After long travel delays, the ship left the port in the morning of 9th of February and entered the Drake Passage on the next day.
After crossing Drake Passage, a first mooring was successfully deployed near Elephant Island and the journey went on through the breathtaking scenery of Antarctic sound, entering the Weddell Sea. There, the team members successfully caried out the first work on sea ice floes and a transect from the continental shelf into the deep ocean, gathering essential data on the influence of tides on ocean mixing and sea ice. Then the journey took them further south, where the ice cover increased and progress became slower and slower to move through the sea ice. In the coming weeks, they will aim to repeat a similar transect to the first one further south, but the ice conditions will determine how achievable this goal will be. In this southern region, they will be searching for dense shelf water that is extremely cold and forms the densest and deepest water masses of the global ocean.
