IFLSCIENCE - Something’s stirring in the Atlantic Meridional Overturning Circulation (AMOC) – and a strange “hole” of cold water in the North Atlantic may provide new clues about what’s up. But is the system on the brink of full-blown collapse, or will it keep churning on despite mounting pressure?
The AMOC is “the conveyor belt of the ocean”, a sea-spanning system of currents that transports warm water from the tropics northwards into the North Atlantic.
It plays a key role in pushing heat and freshwater around the Atlantic via a network of deep and near-surface ocean currents. The system works by transferring warm and salty surface water from the tropics through the North Atlantic. When it approaches the North Pole, it cools and forms sea ice. The remaining water then sinks and is carried southwards in the depths below, completing the cycle.
By bringing warmer water towards the North Pole, it helps to bring warmer weather conditions in Northwest Europe and the North Atlantic. Without the AMOC, these parts of the Northern Hemisphere would be significantly chillier.
In recent years, scientists have suggested that the AMOC is weakening due to changes in water entering the system. The prime drivers of this, shifts in rainfall and Greenland Ice Sheet melt, are both associated with human-driven climate change.
It’s becoming increasingly evident that the slowdown of the AMOC may already be starting to impact our world. New research by the University of California, Riverside, has affirmed the theory that an unusual “hole” of cold water in the North Atlantic near Greenland is the result of the AMOC slowing down.