Unraveling the Eddy-driven Heat Transport in the Agulhas Leakage Region

The Agulhas leakage, which transports warm and salty Indian Ocean water into the Atlantic Ocean, plays a crucial role in global ocean circulation and climate. The mesoscale eddies from the leakage supply the primary source of heat and salt for the Atlantic meridional overturning circulation. This study combines eddy data with Argo profiles from 1993 to 2018 to investigate the three-dimensional structures of eddies, advancing our understanding of eddy-induced transport. Our analysis revealed that both the trapping and stirring processes of eddies influence eddy-induced transport. Anticyclonic eddies are found to transport heat in the meridional direction mainly through propagation (~60%). On the other hand, cyclonic eddies transport heat meridionally to the Atlantic Ocean primarily through the stirring of isotherms in the background field (~25%). These results further confirm that the stirring effect of cyclonic eddies is crucial for evaluating the impact of the Agulhas leakage on the Atlantic Ocean.