Atlantic Currents Offer 10-Year Climate Clues for Europe

Shifts in ocean temperature and salinity in the midlatitude North Atlantic can alter a key part of the ocean circulation near the Arctic up to a decade later, new research shows.

The study, published in Communications Earth & Environment, finds that these “thermohaline anomalies,” or changes in heat and salt, travel north with Atlantic Water and influence the Atlantic Meridional Overturning Circulation (AMOC) in the Nordic Seas.

This branch of the AMOC carries warm water north and sends dense, cold water south at depth, helping to regulate the climate of Europe, including Ireland.

“Rather than being passive signals, these anomalies help control the strength of the Nordic Seas branch of the AMOC,” said lead author Léon Chafik of Stockholm University’s Department of Meteorology. “What happens in the midlatitudes can shape high-latitude ocean circulation years later, and those changes can ripple back south.”

Using 50 years of ocean measurements along with satellite and current meter data, the team traced these anomalies from their origin in the mid-Atlantic to the Arctic gateways north of the Greenland–Scotland Ridge. They found a consistent lag of five to ten years between changes in the North Atlantic and their impact on the Nordic Seas overturning.

The research suggests such anomalies could be used to predict regional climate changes years in advance, and it highlights the importance of maintaining satellite and ocean observation programmes.