What is the salinity of the ocean?

There are many chemicals in seawater that make it salty. Most of them get there from rivers carrying chemicals dissolved out of rock and soil. The main one is sodium chloride, often just called salt. Most seawater has about 35 g (7 teaspoons) of salt in every 1000 g (about a litre) of water. read more

The commonest way to record salinity is to measure the amount of salt in 1,000 g of water, so it is referred to as ‘parts per thousand’ or ppt. Most of the ocean has a salinity of between 34 ppt and 36 ppt. read more

Salinity in rivers, lakes, and the ocean is conceptually simple, but technically challenging to define and measure precisely. Conceptually the salinity is the quantity of dissolved salt content of the water. read more

Although everyone knows that seawater is salty, few know that even small variations in ocean surface salinity (i.e., concentration of dissolved salts) can have dramatic effects on the water cycle and ocean circulation. read more