Recent studies have suggested the possibility of the southern origin of the Atlantic MHT anomalies. These studies have used General Circulation Models (GCMs) to demonstrate covariability between the South Atlantic MOC (SAMOC) and the Southern Hemisphere westerlies at interannual to longer time scales. However, it has been pointed out that the sensitivity of the SAMOC to the changes in the Southern Hemisphere westerlies depends critically on the representation of mesoscale eddies in those models. The observation-based estimates of MHT in the South Atlantic have a wide range of values, which, to some extent, is due to the misrepresentation of the eddy heat transport. Therefore, understanding the variability of the MOC/MHT in the South Atlantic on various time scales and the role of eddies in the South Atlantic are essential ingredients toward achieving decadal predictability of the AMOC and its impact on climate. In our continued effort to diagnose the performance of climate models in the South Atlantic and to better understand the role of eddies, we will (1) diagnose and characterize interannual to decadal variability of the SAMOC in CMIP5 models, (2) explore the impact of resolving eddies in ocean GCMs on interannual to decadal variability of the simulated SAMOC, and (3) quantify the relationship of the SAMOC with the Southern Hemisphere westerlies and the Agulhas leakage.
