North Atlantic 'cold blob' linked to European heatwave

A patch of unusually cold water in the North Atlantic, dubbed the “cold blob,” is being studied as a factor that may intensify heatwaves across Europe. Researchers say the cold anomaly south of Iceland and Greenland can alter the jet stream, creating a slow‑moving high‑pressure system that traps hot air over the continent. Oceanographer Gerard McCarthy of Maynooth University warned that “a cold Atlantic doesn’t necessarily mean a colder Europe,” noting that the cold blob can actually exacerbate extreme temperatures. Climate physicist Marilena Oltmanns of the University of Bremen explained that meltwater from Greenland feeds the cold surface layer, which then reshapes atmospheric circulation.

The phenomenon also raises concerns about the Atlantic Meridional Overturning Circulation (AMOC). A weakening of this conveyor belt could lead to harsher winters in northern Europe in the future, scientists say. Recent studies attribute the cold blob to reduced heat transport by ocean currents rather than surface cooling, underscoring its potential role in both present heat extremes and longer‑term climate shifts.