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Flawed Climate Models? Arctic Ocean Started Getting Warmer Decades Earlier Than We Thought – SciTechDaily

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An international group of researchers reconstructed the recent history of ocean warming at the gateway to the Arctic Ocean in a region called the Fram Strait, between Greenland and Svalbard, and found that the Arctic Ocean has been warming for much longer than earlier records have suggested. Credit: Sara Giansiracusa

The Arctic Ocean has been getting warmer since the beginning of the 20th century – decades earlier than records suggest – due to warmer water flowing into the delicate polar ecosystem from the Atlantic Ocean.

An international group of researchers reconstructed the recent history of ocean warming at the gateway to the Arctic Ocean in a region called the Fram Strait, between Greenland and Svalbard.

Using the chemical signatures found in marine microorganisms, the researchers found that the Arctic Ocean began warming rapidly at the beginning of the last century as warmer and saltier waters flowed in from the Atlantic – a phenomenon called Atlantification – and that this change likely preceded the warming documented by modern instrumental measurements. Since 1900, the ocean temperature has risen by approximately 2 degrees <span aria-describedby="tt" class="glossaryLink" data-cmtooltip="

Celsius
The Celsius scale, also known as the centigrade scale, is a temperature scale named after the Swedish astronomer Anders Celsius. In the Celsius scale, 0 °C is the freezing point of water and 100 °C is the boiling point of water at 1 atm pressure.

“>Celsius, while sea ice has retreated and salinity has increased.

The results, reported in the journal Science Advances, provide the first historical perspective on Atlantification of the Arctic Ocean and reveal a connection with the North Atlantic that is much stronger than previously thought. The connection is capable of shaping Arctic climate variability, which could have important implications for sea-ice retreat and global sea level rise as the polar ice sheets continue to melt.

Taking Ocean Sediment Samples Near Svalbard

Using the chemical signatures found in marine microorganisms, researchers have found that the Arctic Ocean began warming rapidly at the beginning of the last century as warmer and saltier waters flowed in from the Atlantic – a phenomenon called Atlantification. Credit: Sara Giansiracusa

All of the world’s oceans are warming due to climate change, but the Arctic Ocean, the smallest and shallowest of the world’s oceans, is warming fastest of all.

“The rate of warming in the Arctic is more than double the global average, due to feedback mechanisms,” said co-lead author Dr. Francesco Muschitiello from Cambridge’s Department of Geography. “Based on satellite measurements, we know that the Arctic Ocean has been steadily warming, in particular over the past 20 years, but we wanted to place the recent warming into a longer context.”

Atlantification is one of the causes of warming in the Arctic, however instrumental records capable of monitoring this process, such as satellites, only go back about 40 years.

As the Arctic Ocean gets warmer, it causes the ice in the polar region to melt, which in turn affects global sea levels. As the ice melts, it exposes more of the ocean’s surface to the sun, releasing heat and raising air temperatures. As the Arctic continues to warm, it will melt the permafrost, which stores huge amounts of methane, a far more damaging greenhouse gas than carbon dioxide.

The researchers used geochemical and ecological data from ocean sediments to reconstruct the change in water column properties over the past 800 years. They precisely dated sediments using a combination of methods and looked for diagnostic signs of Atlantification, like change in temperature and salinity.

“When we looked at the whole 800-year timescale, our temperature and salinity records look pretty constant,” said co-lead author Dr. Tesi Tommaso from the Institute of Polar Sciences of the National Research Council in Bologna. “But all of a sudden at the start of the 20th century, you get this marked change in temperature and salinity – it really sticks out.”

“The reason for this rapid Atlantification of at the gate of the Arctic Ocean is intriguing,” said Muschitiello. “We compared our results with the ocean circulation at lower latitudes and found there is a strong correlation with the slowdown of dense water formation in the Labrador Sea. In a future warming scenario, the deep circulation in this subpolar region is expected to further decrease because of the thawing of the Greenland ice sheet. Our results imply that we might expect further Arctic Atlantification in the future because of climate change.”

The researchers say that their results also expose a possible flaw in climate models, because they do not reproduce this early Atlantification at the beginning of the last century.

“Climate simulations generally do not reproduce this kind of warming in the Arctic Ocean, meaning there’s an incomplete understanding of the mechanisms driving Atlantification,” said Tommaso. “We rely on these simulations to project future climate change, but the lack of any signs of an early warming in the Arctic Ocean is a missing piece of the puzzle.”

Reference: “Rapid Atlantification along the Fram Strait at the beginning of the 20th century” by Tommaso Tesi, Francesco Muschitiello, Gesine Mollenhauer, Stefano Miserocchi, Leonardo Langone, Chiara Ceccarelli, Giuliana Panieri, Jacopo Chiggiato, Alessio Nogarotto, Jens Hefter, Gianmarco Ingrosso, Federico Giglio, Patrizia Giordano and Lucilla Capotondi, 24 November 2021, Science Advances.
DOI: 10.1126/sciadv.abj2946

Francesco Muschitiello is a Fellow of Sidney Sussex College, Cambridge.

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Scientists observe total solar eclipse in Antarctica – Global Times

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Scientists from the Chilean Union Glacier Station observe a total solar eclipse in Antarctica, Dec. 4, 2021.Photo:Xinhua

 
Scientists from the Chilean Union Glacier Station observe a total solar eclipse in Antarctica, Dec. 4, 2021.Photo:Xinhua

Scientists from the Chilean Union Glacier Station observe a total solar eclipse in Antarctica, Dec. 4, 2021.Photo:Xinhua

 

Scientists from the Chilean Union Glacier Station observe a total solar eclipse in Antarctica, Dec. 4, 2021.Photo:Xinhua

Scientists from the Chilean Union Glacier Station observe a total solar eclipse in Antarctica, Dec. 4, 2021.Photo:Xinhua

 

Photo taken from Chilean Union Glacier Station in Antarctica on Dec. 4, 2021 shows a total solar eclipse.Photo:Xinhua

Photo taken from Chilean Union Glacier Station in Antarctica on Dec. 4, 2021 shows a total solar eclipse.Photo:Xinhua

 

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Dinosaur Tail Found In Chile Could Point To Discovery Of New Species – NDTV

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Paleontologists have discovered 80 percent of the dinosaur’s skeleton.

Santiago:

Chilean paleontologists on Wednesday presented their findings on a dinosaur discovered three years ago in Patagonia which they said had a highly unusual tail that has stumped researchers.

The remains of the Stegouros elengassen were discovered during excavations in 2018 at Cerro Guido, a site known to harbor numerous fossils, by a team who believed they were dealing with an already known species of dinosaur until they examined its tail.

“That was the main surprise,” said Alexander Vargas, one of the paleontologists. “This structure is absolutely amazing.”

“The tail was covered with seven pairs of osteoderms … producing a weapon absolutely different from anything we know in any dinosaur,” added the researcher during a presentation of the discovery at the University of Chile.

The osteoderms — structures of bony plaques located in the dermal layers of the skin – were aligned on either side of the tail, making it resemble a large fern.

Paleontologists have discovered 80 percent of the dinosaur’s skeleton and estimate that the animal lived in the area 71 to 74.9 million years ago. It was about two meters (almost seven feet) long, weighed 150 kilograms (330 pounds) and was a herbivore.

According to the scientists, who published their research in the journal Nature, the animal could represent a hitherto unknown lineage of armored dinosaur never seen in the southern hemisphere but already identified in the northern part of the continent.

“We don’t know why (the tail) evolved. We do know that within armored dinosaur groups there seems to be a tendency to independently develop different osteoderm-based defense mechanisms,” said Sergio Soto, another member of the team.

The Cerro Guido area, in the Las Chinas valley 3,000 km (1,800 miles) south of Santiago, stretches for 15 kilometers. Various rock outcrops contain numerous fossils.

The finds there allowed the scientists to surmise that present-day America and Antarctica were close to each other millions of years ago.

“There is strong evidence that there is a biogeographic link with other parts of the planet, in this case Antarctica and Australia, because we have two armored dinosaurs there closely related” to the Stegouros, said Soto.

(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)

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Chinese Rover Exploring What Appears to Be Cube-Shaped Object on Moon – Futurism

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There’s a Moon cube now! At least, it looks that way based on some intriguing photos from the Chinese lunar rover Yutu-2, released by the country’s space agency this week.

The photos show a distant object that looks like a perfect cube, and China say the rover is headed to check it out.

It’s worth worth noting a few caveats about the photo, spotted yesterday by space journalist Andrew Jones, who described the formation as a “cubic shape.” For one thing, the object is just a few pixels in the photo, meaning it could easily be some sort of optical illusion that’ll be a disappointment up close.

And China has struggled with lunar science communication in the past. In 2019, Yutu-2 “discovered” a “gel-like substance” on the lunar surface, but upon closer inspection it turned out to be, well, rocks. It also trumpeted the discover of a “shard” on the Moon earlier this year, but that turned out to just be another interesting rock. Did we mention that there’s not a lot other than rocks on the Moon?

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Jones, for his part, is managing expectations.

“So yeah, it’s not an obelisk or aliens, but certainly something to check out,” Jones tweeted in followup.

The idea of alien artifacts on the Moon runs deep in popular culture — remember that one scene in “2001: A Space Odyssey”? — but, needless to say, none have been found in reality.

The apparent cube sits in the Von Kármán crater, and China’s space program has been dubbed it, evocatively, the “mystery house.”

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Yutu-2 will spend two or three lunar days traveling to investigate the cube; lunar days are about 50 minutes longer than solar days on Earth.

Jones speculated that the object could be a boulder carved out by an asteroid impact, and posted a photo of a similarly sharply defined boulder found previously on the Moon’s surface.

CNET’s coverage of the most recent discovery agrees with Jones’ analysis, saying the most likely explanation is that the Moon cube is a boulder.

That’s not to say Yutu-2 hasn’t ever found anything cool. In 2019, CNET reported the rover discovered that the Moon’s surface was made of different materials than we previously thought, a discovery that could better predict how Earth’s internal layers might change over time.

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We’re not saying there isn’t weird stuff on the Moon. After all, we just recently found enough buried oxygen under its surface to sustain billions of people. But suffice it to say we aren’t holding our breath over Moon cube, and if it turns out to be anything other than a rock we’ll be really impressed.

More on space: Scientists Discover Enormous Black Hole Right Near Our Galaxy

Care about supporting clean energy adoption? Find out how much money (and planet!) you could save by switching to solar power at UnderstandSolar.com. By signing up through this link, Futurism.com may receive a small commission.

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