20. The Arctic Ocean has been warming together with the Atlantic Ocean since the beginning ofth century, decades earlier than ever, suggests a new study that points to a potential flaw in models currently used to project future climate change.
Researchers said the Arctic Ocean began to warm rapidly at the beginning of the last century by a process called atlantification, as warm and salty waters flowed from the Atlantic.
While the process of the Arctic Ocean turning into a state similar to that of the Atlantic is one of the main drivers of warming in the region, supporting records capable of monitoring this change, such as satellites, go back only 40 years, he explained.
In the new study, published in the journal science advance On Wednesday, an international group of scientists reconstructed the recent history of ocean warming at the entrance to the Arctic Ocean in an area called the Fram Strait between Greenland and Svalbard.
They reconstructed changes in water column properties such as temperature and salinity over the past 800 years – looking for signature signs of Atlantis – by analyzing geochemical and ecological data from ocean sediments and marine microorganisms.
“When we look at the full 800-year time scale, our temperature and salinity record looks fairly stable,” said study co-lead author Tessi Tommaso from the National Research Council’s Institute of Polar Sciences in Bologna, Italy. in a statement.
“But suddenly in his early 20s”th century, you get this remarkable change in temperature and salinity – it really stays outside,” Dr Tommaso said.
As the world’s oceans are warming due to climate change, they say the Arctic Ocean – the smallest and shallowest – is warming at the fastest rate.
Recent studies have shown that the Arctic is warming three times faster than the entire planet and that temperatures in the region are rising by 3 °C above pre-industrial levels. This is melting ice in the polar region, which in turn raises global sea levels and submerges much of the globe.
The process creates a feedback loop, where more melting of ice at the poles exposes more of the ocean surface to the Sun, releasing heat, raising air temperatures, leading to more melting, and so on.
Recent scientific expeditions have also found that these changes could fundamentally alter the marine ecology of the Arctic Ocean, enabling more fish and microbes to colonize the Atlantic and adapt to the northern seas.
And as the Arctic continues to warm, it will also melt the semi-dissolved permafrost landscape in the Northern Hemisphere, including parts of Siberia, which store vast amounts of methane.
The release of this flammable greenhouse gas, which has 80 times more heating power carbon di oxideAbnormal temperature rises in this region, causing wildfires also flare up.
“The rate of warming in the Arctic is more than twice the global average due to feedback mechanisms,” said co-author Francesco Muscatiello, from the University of Cambridge’s Department of Geography.
“Based on satellite measurements, we know that the Arctic Ocean has been warming steadily over the past 20 years, but we wanted to put recent warming in a longer context,” Dr. Muscitiello said.
Scientists said the relationship between the two oceans is capable of shaping Arctic climate variability and could have “important implications” for sea-ice retreat and global sea-level rise as the polar ice sheets continue to melt.
Based on the analysis, the scientists said this warming of the Arctic has a strong relationship with the slowing of a natural circulation process in the Labrador Sea – where cooler air temperatures and surface salinity make water denser and cause its sinking. Is. Down.
“In a future warming scenario, deep circulation in this sub-polar region is expected to decrease further due to the melting of the Greenland ice sheet. Our results mean that we can expect further Arctic atlanticization due to climate change in the future.” can,” warns Dr. Muscatiello.
The scientists also called for better climate models that incorporate these findings to better predict the future effects of climate change.
“Climate simulations generally do not reproduce this kind of warming in the Arctic Ocean, meaning there is an incomplete understanding of the mechanisms driving Atlantis,” explained Dr Tommaso.
“We rely on these simulations to project the future” Climate changeBut the lack of any signs of early warming in the Arctic Ocean is a missing piece of the puzzle,” he said.
Credit: www.independent.co.uk /