Extended Data Fig. 2: Mean upper-layer (top 300 m) salinity budget.

Left column: Eastern South Atlantic (5°E-20°E; 10°S-30°S). Right column: Western South Atlantic (60°W-30°W; 15°S-35°S). a,b Accumulated salinity anomaly (blue), salinity anomaly due to the convergence in oceanic transports (green; see methods), and due to surface fluxes (yellow). c,d Decomposition of oceanic transports contributing to South Atlantic salinification in the ESM-fw. Contributions due to convergences of horizontal advection (light green), horizontal diffusivity (aqua), vertical advection (red), and vertical diffusivity (magenta). e,f Decomposition of surface forcing fluxes into evaporation (brown line), precipitation (dark blue line) and river runoff (cyan line). g,h SST (red line) and evaporation flux (brown line) anomalies. All solid lines indicate 4-member ensemble mean and banding indicates their ensemble ranges.