Concentration basin
From Glossary of Meteorology
concentration basin
A semi-enclosed basin characterized by an excess of evaporation over precipitation plus runoff in which relatively fresh water enters through the strait in the surface layer, is made more saline by the net evaporation, and exits through the strait in a subsurface layer.
The transformed saline water is more dense than the inflowing surface water and therefore sinks. The classic example of a concentration basin is the Mediterranean Sea.
