Recent observational advances from the South Atlantic Meridional overturning circulation Basin-wide Array (SAMBA) at 34.5°S

CHIDICHIMO, M. P.; SAMBA SCIENCE TEAM

Florianópolis

Congreso; Integrated Assessment of Atlantic Marine Ecosystems in space and time - iAtlantic General Assembly 2022; 2022

University of Edinburgh

The South Atlantic acts as a gateway for interocean exchanges between the North Atlantic,the Pacific and Indian basins, and is thus a key place to measure changes in the Atlantic MeridionalOverturning Circulation (AMOC). The South Atlantic MOC Basin-wide Array (SAMBA) has been underdevelopment at 34.5°S since 2009 to observe the variability of volume, heat, and freshwatertransports by the AMOC and related boundary current systems in the South Atlantic. SAMBA is partof the international South Atlantic Meridional Overturning Circulation (SAMOC) initiative, led bycontributors from US, Argentina, Brazil, France, Germany, and South Africa. On the western boundary SAMBA observes the temporal variability of the Brazil Current in the upper ocean and the DeepWestern Boundary Current and the abyssal flows below. The moored observations are also used tostudy deep temperature variations. This presentation will summarise key findings from ongoingSAMBA observing efforts with a focus on the Southwest South Atlantic and will discuss upcomingexpansions to the SAMBA observing system. Within iAtlantic, a tall dynamic height mooringadditionally equipped with current meters and oxygen sensors will be deployed at the westernboundary wedge to provide direct observations of the Brazil Current at the shelf break. This newcapacity to measure oxygen concentrations will be used to understand the role of the Brazil Currentin the oxygen budget of the subtropical South Atlantic, improve tracking of key water masses, andevaluate ecosystem changes, among other important aspects. The SAMBA array near the westernboundary will be further enhanced by the addition of a tall mooring at the base of the continentalslope which will be deployed as part of iAtlantic’s sister project TRIATLAS.