The Southern Ocean sequesters vast amounts of carbon and heat from the atmosphere, thereby mitigating climate warming. This exchange occurs mainly during winter, when intense mixing brings large volumes of deep water in contact with the atmosphere. SO-CUP investigates the magnitude and drivers of carbon uptake with novel wintertime observations made available recently with the deployment of autonomous profiling floats.
The Southern Ocean (SO) is a disproportionately important region, relative to its size, for mitigating the consequences of the anthropogenic climate change, being responsible for 43% and 75% of the ocean uptake of anthropogenic CO2 and heat, respectively. The Subantarctic Mode Water (SAMW) and Antarctic Intermediate Waters (AAIW) effect the bulk of this uptake. Yet the dynamical processes that control the formation of these water masses in the thick winter mixed layers to the north of the SubAntarctic Front (SAF), and the associated drawdown of carbon, are not well understood, primarily as a result of the scarcity of data during winter in this remote region. Hence, the present and future evolution of the SO carbon sink remains the subject of vigorous debate. The main goal of the SO-CUP project is to identify and quantify the processes that control the amount of inorganic carbon that is subducted with the SAMW/AAIW. To do so, the work plan integrates the use of recent in situ observations from biogeochemical Argo floats and a state-of-the-art data-assimilating, high-resolution coupled biogeochemical-physical ocean model (B-SOSE). Through analysis of these novel datasets, which allow for unprecedented data coverage of the SO in winter, the SO-CUP project will produce a major step forward toward understanding the ventilation and carbon uptake processes in the SO, and will help to predict their response to ongoing and future climatic changes.
Principal Investigator: Bieito Fernández Castro
Funding provider: Marie Skłodowska-Curie Actions - H2020 Program - European Commission
Funding dates: September 2020 - September 2022