Deep Currents across the Mid-Atlantic Ridge in the South Atlantic Ocean

Abstract

The SAGA (South Atlantic GAteway) project aims to quantify and monitor the return limb of the Atlantic Meridional Overturning Circulation (AMOC). As part of this initiative, three tall deep-ocean moorings were deployed along 10°W in the South Atlantic, between 21°S and 31°S. This region has recently been identified as the Atlantic Gateway, acting as an observatory for both the northward and southward branches of the AMOC. This study investigates the long-term variability of deep ocean current velocities using observational data from current meters installed on the moorings. The data were collected over a period of two years and one month, covering depths approximately between 2,000 and 4,500 meters. The results suggest that this long-term variability is influenced by Rossby waves, with dominant periods of 256 and 128 days.