- GOC refers to the equatorward transport of cold, deep waters and poleward transport of warm, near-surface waters.
- It is responsible for the transport of carbon and heat among ocean basins and between the ocean and the atmosphere.
- GOC is a system of two connected overturning cells:-
- The upper cell is linked to the formation of North Atlantic Deep Water (NADW) and its shallower return flow to form Atlantic Meridional Overturning Circulation (AMOC).
- The lower cell (referred to as Southern Ocean Meridional Overturning Circulation) is associated with the formation of Antarctic Bottom Water (AMM) and its return flow as Pacific Deep Water (PDW).
- Studies have indicated that tectonically driven changes in ocean gateways such as the closure of the Central American Seaway (CAS), since the late Miocene period, had impacted GOC.
