Oceanography

Monthly and seasonal variations of surface salinity

Seasonal variations of surface salinity depend mainly upon the changes of evaporation and precipitation from season to season over the oceans. The seasonal variations of surface salinity in the open oceans are generally weak, not more than 0.5. These variations are important in regions where the climate is characterized by strong seasonal variations of precipitations. In the polar regions, the melting of ice in the summer and its movement by wind and current cause considerable seasonal variations. The seasonal variations of surface salinity are also more in coastal waters where there is lot of fresh water inflow through rivers. In Arabian Sea coastal waters near Mangalore, the surface salinity is found to vary from 29.6 in the south-west monsoon season (September) to 31.9 in the winter season.