Presented at the 2013 SMOS-Aquarius Science WorkshopAs the western boundary current in the South Atlantic subtropical gyre, the Brazil Current transports warm and salty water southward while the Malvinas Current carries colder and fresher water northward. The excursions of the Brazil Current over the southern limit of the gyre brings saltier water to that region that could undergo to intensive cooling and subsequent subduction due to loss of buoyancy. The heat exchanged between the atmosphere and the ocean is associated with the rate at which the water is subducted due to convective processes. Interannual to intra-decadal changes in the air-sea interaction variables have important impact on water subduction and thus on ocean circulation because of their effect on ocean stratification. The analysis of salinity profiles from Argo data, World Ocean Database and models (GODAS and ECCO) allows us to investigate the salinity variability in the ocean interior. Surface salinity from the Aquarius mission provides us information that connects the ocean signals with the hydrological cycle. Spatial and temporal variability of parameters measured from the microwave radiometer's data (TRMM and AMSR- E) are used to correlate the salinity trends with the hydrological cycle's variables at basin scale. Preliminary results indicate that the moisture fluxes (E-P) using satellite data show increasing (decreasing) trends right over the regions where the salinity increases (decreases).