The average salinity of ocean water is taken as 35 ppm or 35 g / L, but in different oceans and in different parts of each ocean salinity varies. Most salt water in the hot zone.
So, at the equator the salinity of ocean water is 36 g / l, and in temperate latitudes only 33 g / l. In polar latitudes salinity is much less — up to 31 g / l, which is associated with the arrival of the Arctic Ocean fresh river water and snow melt. At the same time, the salinity of the water in the seas quite dramatically different from the ocean. Thus, in the seas of temperate oceanic salinity is much lower, ranging from 15 to 20 g / l, and in the seas of hot climates, it is much higher — up to 42 g / l (for example, in the Red Sea).
Sea water freezes at a lower temperature than fresh. On average, the temperature is the average salinity is around -1,9 ° C.