The Atlantic meridional overturning circulation (MOC)—a deep-ocean process that plays a critical role in regulating Earth’s climate—is primarily driven by cooling waters west of Europe, finds a new international study published Feb. 1 in Science.
In the Atlantic MOC, warm, salty, shallow waters are carried northward from the tropics by currents and wind, and then converted into colder, fresher, deep waters that return southward through the Iceland and Irminger basins. In a departure from the prevailing scientific view, the study shows that most of the conversion from warm to cold water—or ‘overturning’ and its month-to-month variability—is occurring in regions between Greenland and Scotland, rather than in the Labrador Sea off Canada, as many past modeling studies have suggested.
Overturning variability in this northeastern section of the North Atlantic was seven times greater than in the Labrador Sea, and it accounted for 88 percent of the total variance documented across the entire North Atlantic over the 21-month study period.
Read more at Woods Hole Oceanographic Institution
Photo: The R/V Neil Armstrong emerging from Prince Christian Sound, which connects western Greenland to eastern Greenland, during an Overturning in the Subpolar North Atlantic Program expedition. CREDIT: Kent Sheasley, Woods Hole Oceanographic Institution