The Agulhas leakage around South Africa is the main source of the warm and salty waters carried towards the subpolar North Atlantic as the upper limb of the MOC. The Agulhas leakage region is characterized by vigorous variability on intraseasonal to interannual timescales9 shedding the largest mesoscale eddies in the world ocean10, which are the dominating vehicles transporting and releasing the Indian Ocean waters into the Atlantic11. Observational palaeoclimate studies have suggested a broken inter-ocean exchange on centurial to millennial timescales12, and ocean climate model studies13, 14 have elucidated the potential of the inter-ocean exchange of heat and salt to alter the long-term MOC response. However, large uncertainties in those studies remain, owing to unresolved mesoscale processes15 that govern the dynamics and strength of the Agulhas leakage16; the present study focuses on those effects on decadal timescales.
The MOC is the meridional overturning circulation see Thermohaline circulation in Wikipedia.
