• Overturning maximum is 15.64 ± 1.39 Sv; Meridional heat and freshwater transport are 0.27 ± 0.10 PW and 0.23 ± 0.02 Sv, respectively.
• Excluding the mesoscale eddies from the section increased the meridional heat transport by 0.12 PW.
• The distribution of water masses and currents reflects the favorable position of the section for observing.
The South Atlantic Meridional Overturning Circulation and Mesoscale Eddies in the First GO‐SHIP Section at 34.5ºS
Abstract - https://doi.org/10.1029/2020JC016962
The Atlantic Meridional Overturning Circulation (AMOC) is a crucial element of the global ocean circulation and climate. It connects the Southern Ocean to the northern North Atlantic, and is responsible for the interhemispheric northward transport of heat and freshwater. The South Atlantic is a crossroad for water masses from the Southern, the Indian and the North Atlantic oceans. This paper analyzes the first full‐ocean‐depth trans‐basin measurements of the southernmost enclosed section of the Atlantic between South Africa and Brazil along 34.5°S. Our results confirm a northward transport of heat at this latitude. We also found a complex water mass structure and dynamics, characterized by intense boundary currents and mesoscale eddies. It is the sum of these elements that is not only crucial for the Atlantic but also for the global ocean circulation and climate.
Figure 1. South Atlantic region with the bathymetry from ETOPO2 (Smith & Sandwell, 1997) shaded in grey. In red and blue shades is shown the long-term eddy kinetic energy (EKE) -mean kinetic energy (MKE) computed from Duacs/AVISO surface geostrophic velocity fields. The long term mean dynamic topography also from Duacs/AVISO is shown as black contours to depict the mean basin circulation. The major bathymetric features are labeled in orange text. GO-SHIP sections are shown as orange lines and the MSM60 cruise track in red. Red diamonds over 34.5oS line show the location of moorings deployed (taken from Meinen et al., 2017 and Kersalé et al., 2019).