Abruptly attenuated carbon sequestration with Weddell Sea dense waters by 2100

Antarctic Bottom Water formation, such as in the Weddell Sea, is an efficient vector for carbon sequestration on time scales of centuries. Possible changes in carbon sequestration under changing environmental conditions are unquantified to date, mainly due to difficulties in simulating the relevant processes on high-latitude continental shelves. In this presentation, I will show results from model simulations with a setup including both ice-shelf cavities and oceanic carbon cycling and demonstrate that by 2100, deep-ocean carbon accumulation in the southern Weddell Sea is abruptly attenuated to only 40% of the 1990s rate in a high-emission scenario. In my talk, I will assess deep-ocean carbon budgets and water mass transformations to attribute this reduction in deep-ocean carbon transfer to changes in freshwater fluxes and hence density distributions on the continental shelf.

See relevant publication here.