A strange cold zone in the Atlantic is linked to the slowdown in a major ocean current: Amoc

For more than a century. Therefore, A cold water area south of Greenland resisted the general warming of the Atlantic Ocean, thus fueling scientific debate. Similarly, A new study identifies the cause of this phenomenon: long -term weakening of an important ocean circulation system.

Researchers from the University of California in Riverside demonstrate that one explanation corresponds to the observed patterns of temperature. Similarly. Therefore, salinity of the ocean: The meridian circulation of the Atlantic (AMOC, Atlantic Meridional Overturning Circulation) is slowing strange cold zone atlantic linked down. This system of massive currents contributes to regulating the climate by moving the warm. In addition, salty waters to the north, and the colder waters to the south, in depth.

A rare. Therefore. Furthermore, abnormal cold zone in the North Atlantic – Strange cold zone atlantic linked – Strange cold zone atlantic linked new

“People have been wondering for a long time why this cold zone has existed,” said the climatologist strange cold zone atlantic linked new of the University of California in Riverside (UCR), Wei Liu, who led the study alongside the Kai-Yuan Li doctoral student. However, “We have discovered that the most likely explanation is a weakening of the Amoc. Furthermore, »»

The Amoc works like a gigantic treadmill, carrying heat and salt from the tropics to the North Atlantic. Moreover, Its slowdown means that a lesser amount of hot. salty water reaches the subpolar region, which causes the cooling and dilution observed in the south of Greenland.

When the current weakens. less heat. salt reach the North Atlantic, which strange cold zone atlantic linked causes more cold and less salty surface water. This is why salinity and temperature data can be used to assess the intensity of the Amoc.

Liu. Li analyzed a century of these data a century. Because the direct observations of the AMOC only date back to twenty years. From these long -term recordings. strange cold zone atlantic linked new they have rebuilt the evolution of the traffic system and compared it to nearly 100 different climatic models.

As shown in the article published in Communications Earth & Environment. Only the models simulating a weakening of the Amoc corresponded to the real data. The models supposing a stronger circulation spread out clearly.

“It is a very solid correlation,” says Li. “If we compare observations to all simulations. Only the scenario of a weakening of the Amoc makes it possible to reproduce cooling in this region. »»

The study also revealed that this weakening is correlated with a drop in salinity. strange cold zone atlantic linked Another clear sign that a lesser amount of hot and salty water is transported north.

Impacts expected from this connection

The consequences are large. The anomaly observed in southern Greenland is important not only because of its unusual character. but also because it is one of the regions most strange cold zone atlantic linked new sensitive to changes in ocean circulation. It influences climatic diets throughout Europe. changing precipitation. disturbing jet current, this altitude air current which directs meteorological systems and contributes to regulating temperatures in North America and Europe.

The slowdown in the Amoc could also unbalance marine ecosystems. variations in salinity and temperature playing a key role in the distribution of species.

These results could help resolve the debate between climatologists on the origin of the cooling observed in the south of. Greenland: Is it mainly due to ocean dynamics. atmospheric factors, such as aerosol pollution? Many recent models suggested this last hypothesis. providing for a strengthening strange cold zone atlantic linked of the Amoc linked to the drop in aerosol emissions. But these models failed to reproduce the cooling observed in the field.

“Our results show that only models incorporating a weakening of the Amoc are fair”, says Wei Liu. “This means that many recent strange cold zone atlantic linked new models are too sensitive to aerosol changes and less precise for this region. »»

By correcting this discrepancy. the study strengthens the reliability of upcoming climatic forecasts. In particular for Europe, where the influence of the Amoc is more marked.

It also highlights the ability to draw solid conclusions from indirect data. In the absence of ancient direct observations on the AMOC. temperature and salinity statements are a precious alternative to detect long -term developments and refine future climatic scenarios.

“We do not have direct measures dating back to a century. but temperature and salinity data allow us to clearly reconstruct the past,” concludes Kai-Yuan Li. “This work shows that strange cold zone atlantic linked the Amoc has weakened for more than a century. and this trend should continue if greenhouse gases continue to increase. »»

As the climate system evolves. the influence of the cold zone south of Greenland could increase. By identifying its origins, scientists hope to prepare societies for future challenges better.

“The method we have used is a powerful tool to understand how the system has changed. and towards what direction it could evolve if the greenhouse gases continue to increase ”, said Kai-Yuan Li.

Strange cold zone atlantic linked new

Strange cold zone atlantic linked

Article reference:

Kai-Yuan Li et al. Weakened Atlantic Meridional Overturning Circulation causes the historical North Atlantic Warming Hole, Communications Earth & Environment (2025). DOI: 10.1038/s43247-025-02403-0