In the Atlantic Ocean, a giant ‘conveyor belt’ carries warm waters from the tropics into the North Atlantic, where they cool and sink and then return southwards in the deep ocean.
In the Atlantic Ocean, a giant ‘conveyor belt’ carries warm waters from the tropics into the North Atlantic, where they cool and sink and then return southwards in the deep ocean. This circulation pattern is an important player in the global climate, regulating weather patterns in the Arctic, Europe, and around the world. Evidence increasingly suggests that this system is slowing down, and some scientists fear it could have major effects, such as causing temperatures to dive in Europe and warming the waters off the East coast of the United States, potentially harming fisheries and exacerbating hurricanes.
A new study published in Nature Communications provides insight into how quickly these changes could take effect if the system continues weakening. Led by scientists at Columbia’s Lamont-Doherty Earth Observatory in collaboration with the Norwegian Research Centre, the study is the first to precisely determine the time lags between past changes to the ocean conveyor belt and major climate changes.
The team studied a key section of the ocean current pattern, known as the Atlantic Meridional Overturning Circulation (AMOC). They zeroed in on a section where water sinks from the surface to the bottom of the North Atlantic. They confirmed that the AMOC started weakening about 400 years before a major cold snap 13,000 years ago, and began strengthening again about 400 years before an abrupt warming 11,000 years ago.
Read more at Earth Institute at Columbia University
Image: Simplified diagram of the Atlantic Meridional Overturning Circulation. It carries warm water from the tropics (red arrows) into the North Atlantic, where the water cools and sinks before flowing back south (yellow arrows). This pattern plays an important role in regulating climate in the North Atlantic as well as the rest of the world. (Credit: Muschitiello et al., Nature Communications, 2019)
