Interannual to Decadal Variability of Meridional Transports Across the SAMOC Basin Wide Array (SAMBA) in Simulations with an Eddy-resolving Global Ocean Model

Results of numerical experiments with ocean general circulation models show increasing trends in the Agulhas leakage and in the meridional heat transport in the South Atlantic. To further investigate impacts of interannual to interdecadal changes in the wind forcing on the circulation and meridional transports in the South Atlantic, a set of simulations is conducted with an eddy-resolving global implementation of the Hybrid Coordinate Ocean Model (HYCOM). Firstly, a climatological experiment is run, forced with monthly means of the NCEP Reanalysis products, with no interannual variability. The last ten years of a two-decades run are then analyzed. The mean circulation patterns in the South Atlantic are well represented, as compared with observations and results of other models. The outputs show no long term trends, ruling out the hypothesis of any noticeable model’s internal drift. Another experiments is then run, forced with interannual variability, from 1949 to the present. The results are compared with those of the climatological experiment, focusing on the circulation, the inter-ocean exchanges, the Agulhas leakage and the meridional transports in the South Atlantic.