Friday , August 12 2022

One Greenland Glacier has started to grow again, but that doesn't mean what you think t



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The glacier that shrinks fastest in Greenland has made an unexpected turn.

Although it has been melting for 20 years, the Jakobshavn Glacier in West Greenland – famous for producing the iceberg and sunk the Titanic – has now started to grow.

Since the 1980s, waters have been growing warmer around Baffin Bay, where the glacier meets the sea. However, recent NASA data shows that in 2016, sea currents have grown cooler.

As a result, the Jakobshavn Glacier glacier has been thickening, slower and growing towards the sea.

The waters around the mouth of the glacier – also known as Sermeq Kujalleq in the Green Island – are the most cold now since the 1980s.

"At first we didn't think so," said glaciologist Ala Khazendar of NASA Jet Drive Laboratory. "We had assumed that Jakobshavn would continue to go on as it had been over the last 20 years."

retreat jakobshavnJakobshavn calving front from 1851 to 2006. (NASA Earth Observatory)

But over the last three years, cold water has come to come, according to data from the NASA Melting Greenland (OMG) mission and other sources.

In a newspaper, Khazendar and his team have identified the cause – and, yes, it's only temporary.

The team tracked the current using observations and an ocean modeling system developed by NASA to fill the data gaps.

The cooling began in the North Atlantic Ocean, 966 kilometers (600 miles) to the south of the glacier, triggered by a climate pattern known as the North Atlantic Oscillation (NAO): every five to 20 years, atmospheric pressure at sea level varies, eventually leading to either warming or cooling, which is then glued to the north by the ocean currents up south coast. Greenland West.

In 2016, the water in this current was cooler 1.5 degrees Celsius, cooling the Atlantic around Greenland about 1 degree Celsius; this made her way to the mouth of Jakobshavn, allowing the ice to thicken.

It seems like such a small increase for such a big effect, is it not? Even the researchers were surprised.

"We didn't think the sea could be so important," says OMG investigator Josh Willis of the Jet Propulsion Laboratory t National Geographic.

But, the pendulum will inevitably turn back, and the glacier will shrink again.

Meanwhile, the rest of the Greenland ice sheet is still falling; and, even if this small growth continued, it could not compensate for the profound losses experienced to date.

He broke some of the oldest and thickest ice in the Arctic last year – the first time ever recorded. And it happened twice.

Over half of the Arctic's permanent ice has melted; and ice and snow melting have revealed the Arctic landscapes that have been hidden for 40,000 years.

Indeed, according to a report by the United Nations last year, we do not return. The damage was done; the Arctic is warming up, and there is nothing we can do to stop it.

Jakobshavn has been melting since the beginning of the 2000s, when it lost its ice shelf. This floating platform of ice slows the flow of glaciers; so, when Jakobshavn broke away, his flow increased.

Since then, its melting has been accelerating, and the front of the glacier retreating from the ocean. Between 2013 and 2016, it lost 152 meters (500 feet) thick.

Jakobshavn has not even come close to replacing that bulk, and it probably won't. The NAO cooling is unlikely to heat outdoors.

"Jakobshavn has a temporary cut of this climate pattern. But eventually the seas are getting warmer. And seeing the seas having such a big impact on the glaciers is bad news for a leaflet. T Greenland ice, "Willis said.

This research shows that a glacial recession is not a one-way trend, but it does not show the reversal of climate change. It shows that the effects are a little more complicated than we thought, but ultimately that bird has flown.

"This cooling is going to pass," Khazendar said National Geographic. "When it does, the glacier will retreat even faster than it was from the front."

The research has been published in Geoscience Nature.

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