The Gulf Stream, on which Europe’s climate depends, is record weak
The Atlantic Ocean water circulation, which transfers heat to the northern hemisphere and plays a key role in regulating global climate, is rapidly weakening. This could mean permanent changes in the climate of Europe and eastern North America.
The new study by scientistsow from University College London (UCL), Woods Hole Oceanographic Institution (WHOI) and the University of Reading shows that the global ocean circulation system is currently at its weakest since the last 1600 years. If the system continues to weaken, it could cause permanent changes in the conditions of theoin weather m.in. for the eastern part of America Polnoc and Europe.
Circulation wod Atlantic plays a key role in regulating global climate. This system is a complex mechanism. depends largely on the salinity and temperature of the water, but is also influenced by tides or the Earth’s rotation.
Being in constant motion, the circulation system in theod subsurface is called the global transmission belt or, more expertly, the thermohaline circulation. Its Atlantic part, in turn, is called the Atlantic meridional overturning circulation (AMOC) and includes the Gulf Stream, or Gulf Stream, ktory sends warm and salty water from around the rownik to the poNorth Atlantic, where heat is released into the atmosphere, which in turn warms western Europe. The waters around Labrador and Greenland then cool and increase in density, before sinking to great depths and returning to the south.
– Our study provides the first comprehensive analysis of the recordoin sedimentoin the oceanic, whichore indicate that the weakening of the circulation in theod Atlantic began at the end of the so-called. The Little Ice Age, a prolonged period of cold, ktorego’s end occurred around 1850 – said Delia Oppo of WHOI, coohe author of the study, whoore was published in „Nature”.
Headohe study’s lead author, Dr. David Thornalley of UCL, believes that when pohe North Atlantic began to warm at the end of the Little Ice Age, freshwater from melting ice sheets and glaciersoin the surrounding ArcticoAMOC force. The huge influx of fresh water has diluted seawater, making it lighter and less able to go deep until wod of the deep sea, slowing down the AMOC system.
In studying this circulation, the scientists first analyzed the size of sediment grainsoin deposited by deep-sea currents. The larger the grains, the stronger the current. They then applied rodifferent methods to reconstruct the surface ocean temperatures in regions where theorych temperature affects the strength of the AMOC circulation.
– The results of our analysis showed that AMOC has weakened by about 15-20 percent over the past 150 years – acknowledged by Thornalley. This drop in flow of about 3 million metersoin cubic meters of water per second. For the cfoination is about the volume of about 15 Amazon.
This points to a gap in current global climate models – considers another wspołautor of the study, Jon Robson of the University of Reading. – Circulation poThe North Atlantic is much more variable than previously thought. It is important to understand why the models underestimate the decline in AMOC, ktory we have observed – explained Robson. They may have misestimated the amount of freshwater flowing into the system.
Another study published in the same issue „Nature” conducted by scientistoin from the Potsdam Institute for Climate Impact Research, took a look at climate model data and past sea surface temperatures. The researchers found that the AMOC has been weakening faster since around 1950. According to them, it is related to human-induced climate change.
These two new studies provide complementary evidence of theow on that today’s AMOC circulation is extremely weak. – Supportolations for both of these periodsoin undermining the AMOC – the end of the Little Ice Age and the last decades – is that we are talking about a time of warming, as well as an increase in the melting of the ice caps and glaciersow. This condition will continue to happen because of continued carbon dioxide emissions – Thornalley said.
What consequences this may have? From the point of view of our geographic location, the most important is the decline in the power of Golfstrom. Researchers estimate that this may be linked to lower temperatures during European winters. Turbulence can also occur in summer. Heat wavesow may occur much more frequently and on both sides of the Atlantic.
These effects may worsen as the Gulf Stream weakens. Changes will also occur in marine ecosystems. Weakening circulation could affect populations of sea creatures living in the area. However, no climate models have ready answers.
The researchers do not rule out that just as they were surprised by the unnoticed changes in AMOC circulation, rosurprises may also occur in the future.