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The English version of our glossary is currently under construction and will be regularly updated.

Meridional Overturning Circulation (MOC)

This global “conveyor belt” redistributes massive amounts of heat, salt, nutrients and gases among all oceans.

Meridional (north/south) overturning circulation in the ocean, which is quantified using the zonal (east-west) sum of mass transport in depth or density layers. In the North Atlantic, outside the subtropical regions the MOC (which, in principle, is a quantifiable parameter) is often referred to as thermohaline circulation (THC), which represents a conceptual interpretation. It should be kept in mind that the MOC can also contain shallower, wind-driven overturning cells (as can be found in the upper ocean layers in the tropics and subtropics), in which warm (and therefore lighter), poleward-flowing water is transformed into denser water and flows back equatorward in deeper layers.

Overview of thermohaline circulation