The following visualization shows, based on a simulation with the high resolution global ocean circulation model MPIOM TP6M, the salinity at 75 meters depth for the term of a year. Highly saline water is shown in shades of red to violet while fresher (less saline) water is shown in shades of blue. Additionally, the ocean current velocity at 75 m depth is shown by bump shading.
The high salinity in the Mediterranean Sea is caused by the imbalance among strong evaporation, relatively weak fresh water inflow from rivers, and weak precipitation. The narrow Strait of Gilbraltar limits the exchange of Mediterranean water with that of the Atlantic.
Relatively salty water is transported by the Gulf Stream from tropical latitudes towards Europe. In contrast to the Atlantic Ocean, the Pacific is much less saline.