A wide -ranging system of marine streams in the North Atlantic is treating very strangely, possibly because it is approaching a tapping point, showing a new analysis of clam shells.
The North Atlantic sub polar gear plays a key role in bringing the heat to the northern hemisphere, and it is part of a very large network of the Atlantic Mediary Ultrameling rotation (AMOC). But new evidence suggests that all polar gender has been losing stability since the 1950s, which means that the circulation of the gurr may be significantly weakened in the next decades, researchers published in a study published today (October 3). Science development.
The North Atlantic Sub Polar Gire is a organ of AMOC, but it can cross a tiping point independently from the stream of the network. Specifically, climate results for Europe will be similar Those who will be dynamic from the elimination of AMOCEarlano Nawa said, though they may be less severe because the AMOC is so big. However, “even if the consequences are not as destructive as the AMOC eliminates, weakening a sub -polar gender can have adverse effects of climate.”
Previous research shows The AMOC may fall in the near future Because its main engine – a wrinkle of dense water from the North Atlantic surface and to the Arctic Oceans to the sea edge – is failing. This wrinkle, which was still made of extremely cold and salty water, is reduced to melting water and is hot from the rising global temperature, ie, in some places, water is no longer dense to sink properly. (Cold, salty water is less than hot, less salty water.)
A similar destiny is expected for the northern Atlantic sub polar gender, which also relies on the surface water sinking on the floor of the sea. Arilano Nawa said that the wrinkle of dense water in the core part of the gender keeps the rotating streams. He said, but this system is also partially driven by air, so a complete end is unlikely.
North Atlantic Sub Polar is a branch of AMOC, so elimination of an AMOC involves dramatically weakening the gender. On the contrary, Arilano Nawa said, on the contrary, to weaken all polar geera, it does not mean that the AMOC has fallen.
He explained, “All the polar girps can be weakened without falling the AMOC.” This happened during the transfer of the small ice age, which took place in the 13th and 14th centuries. “
The small ice age, which lasted from about 1250 to 1800s, is one of the coldest periods according to the record in the northern hemisphere. The last snowy period. The average temperature has decreased by about 3. 3.6 degrees Fahrenheit (2 degrees Celsius), which in winter freezes solid rivers and ports in Europe and North America, which mobilizes agricultural crises and spreads medieval society into chaos. New York. Although factors such as volcano eruptions and reducing solar activity played a vital role at the beginning of the small icy period, northern Atlantic sub polar gener Thought he had played an important role In strengthening it.
With Climate changeEarlano Nawa said, now the situation is dramatically different than the 13th century, so scientists do not know whether another small age of ice is possible, Arilano Nava said. However, it explains some of the effects of climate that can be in our way.
Cluses in words
For new research, Arilano Nava and his colleagues analyzed existing datases derived from two clam species in northern Atlantic: Arctica Island And Glycemares glycemares. Claims record the sea information in their shells as they grow. For example, they absorb different forms of elements such as oxygen that can give researchers about the marine process over time.
“With the Claim record, we have a good dating for every layer,” said Arilano Nawa. “
Researchers have compiled 25 datases to create a high resolution image of the North Atlantic Sub Polar gear in the last 150 years. They received two strong indicators of instability. All recently continues and suggests that all polar gear is approaching a tiping point as a result Global warmingArilano Nawa said, which supports previous observations and research.
He said, but the second signal was a surprise. Klim’s data revealed that the sub -polar gender was unstable for a few years in the run -up at the northern Atlantic Regime Shift of the 1920s. The incident mentioned earlier was the feature of strengthening the streams in the gear. Arilano Nawa said that the possibility of volatility in all polar gear causes a change in the government of the 1920s, and the timeline shows that the elimination of its small ice age during the instability period could reflect the recovery of the sub polers.
“He had to be strengthened at some point, but this is not something we have complete evidence because we did not dive into these mechanisms,” he said.
Earlano Nawa said, regardless of the instability in the early 20th century, was actually an indication that the sub -polar gender was returning to his full force, the signal in the Klim’s data and the northern Atlantic Regime Shift of the 1920s showed that the results showed strong results.
“If you observe the waste of stability, after which, rapid changes, you are sure that these are preliminary warning indicators for a sudden change,” he said.
However, another expert was less convinced. “Datases are very useful because they are very well -died and allow the insights of climate change on a year -long basis,” David ThornerProfessor of Ocean and Water Science at University College London, who was not involved in the study, told Science directly in an email.
Thorneley said, but the analysis did not directly linked the samples found in the claims of the clam to the physical properties in the sea, nor did the sub -polar girlfriend provide strong support to the change in the operation method. He said, “I am skeptical of this interpretation.
Regarding the ongoing instability of the Northern Atlantic Sub Polar gener, Arilano Nawa said he and his team have moved forward to make a map of possible climate tricks, which could unlock.
“We do not know what the tiping point is,” he said. “It can be immovable,… but we may first weaken a sub polersgare, and it’s definitely disturbing.”
