The North Atlantic cold blob may be worsening Europe’s heatwave by disrupting ocean and weather patterns linked to the Atlantic Meridional Overturning Circulation, scientists said.
The cold patch sits south of Greenland and Iceland, between Greenland and Ireland, while much of Europe faces extreme heat.
Parts of Europe crossed 100 degrees Fahrenheit during the heatwave. It also cited France’s high temperatures, school closures in Britain and more than 1,000 heat-related deaths.
Scientists call the cold patch the “cold blob” because it has cooled while most of the global ocean has warmed. Studies indicate the area has cooled by up to 0.9 degrees Celsius since 1900. Global sea surface temperatures rose by about 1 degree Celsius over the same period.
Scientists link the feature to freshwater from melting Greenland ice. That freshwater can reduce ocean salinity and disrupt the AMOC, which carries warm tropical water northward.
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A weakened AMOC can alter air pressure and storm-track patterns over the North Atlantic.
Researchers warn that further weakening could bring harsher European weather, drought risks in parts of Asia and Africa, and higher sea levels.
Some studies have raised the risk of an AMOC tipping event this century, though scientists still debate the timing and probability.