From 2008 to 2016 a widespread cooling ranging from 0.6°C to more than 2.0°C has chilled effectively the entire oceanic region from E. Canada to N. Iceland to S. Europe. The cooling persists year-round and extends from the surface down to depths of 800 m.
Image Source: Bryden et al., 2020
A year ago scientists revealed a large swath of the North Atlantic surface had cooled at a rate of -0.78°C per decade between 2004 and 2017 (Fröb et al., 2019).
Image Source: Fröb et al., 2019
The cooling has recently sprawled into the Arctic regions, as the upper ocean waters in Disko Bay (West Greenland) have just been hit with a ~2°C cooling since 2014 (Khazendar et al., 2019).
Image Source: Khazendar et al., 2019
A new study (Bryden et al., 2020) suggests the magnitude, rapidity, and extent of this cooling may have been underestimated.
A cooling of “more than 2°C” in just 8 years (2008-2016) has been reported for nearly the entire ocean region south of Iceland.
The cooling persists year-round and extends from the “surface down to 800 m depth”.
From 40°N to 70°N, and from 40°W to 0°W, average temperatures have plunged 0.6°C from 2008 to 2016 – also to depths of 800 m.
To put these thermal changes into perspective, consider it took the global oceans 55 years (1955-2010) to warm 0.18°C (0.27 W/m²) in the 700 m layer (Levitus et al., 2012).
It is unknown to what extent the cooling will permeate other regions of the ocean. Nor is it known how long the cooling will persist. Or worsen.