
The researchers have used data from satellite and measurements in the ocean, modelling and a machine learning technique to document and explain for the first time the most-recent and ongoing cooling-to-warming transition of the Subpolar North Atlantic.
“In this study, we have established that these waters that are causing the current warming period originated from the Gulf Stream outside the US east coast. This means that less cold waters have made it to the eastern Subpolar North Atlantic since 2016” says co-author Léon Chafik at the Department of Meteorology and Bolin Centre for Climate Research, Stockholm University.
How can this change of temperature in the Subpolar North Atlantic be explained? By using satellite data measuring ocean sea level and currents (known as satellite altimetry) and combining it with data from ARGO floats (ocean robots), the researchers were able to track the origin of these warm waters.

What consequences does this warming have? “The water in the Subpolar North Atlantic continues to the Arctic region following ocean currents. This means that any temperature change in the Subpolar region has major consequences for the polar region and the sea ice. It is very likely that this warming will accelerate the loss of sea-ice once it reaches the Arctic Ocean. This may amplify the global consequences of a reduced Arctic sea ice” says Léon Chafik
Read the article by Damien Desbruyères, Léon Chafik, and Guillaume Maze on Communications Earth & Environment, https://www.nature.com/articles/s43247-021-00120-y