Linkages to the Atlantic Meridional Overturning Circulation (AMOC)

Schematic representation of the AMOC
Schematic representation of the AMOC which transports relatively warm water (red) poleward in the upper layers of the North Atlantic and relatively cold (blue) waters (formed by winter cooling) equatorward in its lower layers.

The Meridional Overturning Circulation (MOC), sometimes referred to as the "global ocean conveyor belt", is an important component of the global atmosphere-ice-ocean climate system and an important factor to the global carbon cycle. The MOC redistributes heat between polar and equatorial regions and among the Earth's ocean basins and atmosphere, and contributes to the sequestration of anthropogenic carbon by the global ocean.

The NW Atlantic off eastern Canada is a key area to the Atlantic component of the MOC (referred to as the AMOC). This is because of the formation, through severe winter surface cooling, of a major intermediate-depth water mass called Labrador Sea Water (LSW) and of the equatorward transport of LSW and deep water masses along the North Atlantic's western margin by the Deep Western Boundary Current (DWBC). The DWBC is the lower limb of the AMOC such that its changes are important to the global climate system and carbon cycle.

The Ocean Sciences and Ecosystem Research Divisions carry out important research on ocean climate and biogeochemical variability in the Labrador Sea, and the linkages of this variability with the AMOC. Research activities include:

Map showing locations of AZOMP and AZMP
Map showing locations of AZOMP and AZMP sections and recent current measurement studies which are contributing to linking water mass variability in the NW Atlantic to the AMOC.

The observational components of this research are coordinated with DFO's ocean climate and ecosystem monitoring programs - AZOMP and AZMP - and with various moored current measurement programs (see Currents over the NW Atlantic Continental Margin)

For further information on international studies of the AMOC, see RAPID and MOCHA