Sea surface salinity observations contribute to monitoring the global water cycle (evaporation, precipitation and glacier and river runoff). On large scales, surface salinity can be used to infer long-term changes of the global hydrological cycle. Surface salinity, together with surface temperature, is indicative of the surface expression of ocean frontal features and eddies.
Sea Surface Salinity
Sea Surface Salinity Map
Figure: NASA Aquarius Mission - SMAP Sea Surface Salinity, April 2016.