(Invitada, charla inaugural de 30') Recent advances in South Atlantic and Southern Ocean Meridional Overturning Circulation

CHIDICHIMO, M. P.

Cape Town

Simposio; IAPSO-IAMAS-IAGAS Joint Assembly; 2017

IAPSO-IAMAS-IAGAS

(INVITED) The meridional overturning circulation (MOC) of the ocean plays a key role in the time-variable coupled climate system because of its ability to store and transport heat, fresh water and carbon globally. The South Atlantic Ocean has a unique location connecting the North Atlantic Ocean, were the largest volume of deep water is formed, with the other ocean basins. The North Atlantic Deep Water flows southward along the coast of South America and through the basin interior and it is compensated by northward flow of upper and intermediate waters across the basin. As a result, the South Atlantic transports heat from the pole towards the equator. The Pacific Ocean and the Indian Ocean are connected with the Atlantic basin through circulation pathways south of Africa and South America in the Agulhas retroflection and in the Drake Passage regions, respectively. Models suggest that changes generated in the Southern Ocean are transmitted through inter-ocean exchanges to the northern basins. Models and observations have shown that the water masses formed in remote regions and subsequently transiting the South Atlantic are significantly altered within this basin by processes such as mixing, advection, and local air-sea interactions, which are more intense in regions of high mesoscale activity. These modifications may lead to changes of the MOC strength and variability and the associated meridional heat and freshwater transports. In the past decade, the South Atlantic and Southern Oceans observing systems have expanded with moored arrays and intense hydrographic surveys revealing important information to increase our knowledge and understanding of the variability introduced to the MOC. In this talk, these observational efforts will be reviewed and discussed.