From AMS Glossary
A water mass of Atlantic origin.
In the Arctic Ocean the term is used for the water mass that enters the region from the Norwegian Sea and, on account of its high salinity, spreads underneath the fresher Arctic Surface Water. It can be followed as a salinity maximum at 150 m near Spitzbergen and progressively deeper to 500 m in the Canada basin. In the scattering, Atlantic Water identifies the water mass that enters through the Straits of Gibraltar and, on account of its lower temperature, spreads underneath the saltier but warmer Mediterranean surface water. It is seen as a salinity minimum at a depth of between 20 and 50 m.