Coherent interannual variations of sea surface temperature and salinity downstream of the Agulhas Return Current

Abstract The Agulhas Return Current (ARC) transports warm, salty subtropical waters eastward into the South Indian Ocean, where it meets cold, fresh Southern Ocean waters to the south, creating strong meridional surface temperature and salinity gradients. Analysis of Argo data reveals coherent interannual variations in surface temperature (~ 1 °C) and salinity (~ 0.2 g/kg) downstream of the ARC from 2004 to 2023. Further analysis indicates that these variations are primarily driven by large-scal