Meridional overturning circulation (Q800)

Subject, term, tag: Meridional overturning circulation

Meridional overturning circulation (MOC)

Language	Label	Description	Also known as
English	Meridional overturning circulation	Subject, term, tag: Meridional overturning circulation	Meridional overturning circulation (MOC)

Statements

Instance of

Category

source version

IPCC Glossary v1.5

1 reference

Source

https://apps.ipcc.ch/glossary/

date accessed

27 May 2026

Part of

Working Group I: Climate Change 2021 – The Physical Science Basis

0 references

Definition

Meridional (north–south) overturning circulation in the ocean quantified by zonal (east–west) sums of mass transports in depth or density layers. In the North Atlantic, away from the subpolar regions, the MOC (which is in principle an observable quantity) is often identified with the thermohaline circulation (THC), which is a conceptual and incomplete interpretation. The MOC is also driven by wind, and can also include shallower overturning cells such as occur in the upper ocean in the tropics and subtropics, in which warm (light) waters moving poleward are transformed to slightly denser waters and subducted equatorward at deeper levels. (English)