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March 26 (UPI) – For two decades, the Jakobshavn Glacier of Greenland has been rapidly melting. It is the fastest and most enlightening glacier on the island. But according to new data collected by NASA scientists, the glacier is growing again.
Although Jakobshavn continues to lose more ice than snow, which contributes to sea level rise, the glacier is no longer in decline or in thinning. Jakobshavn thickens and advances towards the ocean. It also flows more slowly.
According to new research by scientists at NASA's Jet Propulsion Laboratory, the glacier turnaround is explained by the arrival of cold coastal water. The research was published in the journal Nature Geoscience this week.
Cold currents arrived for the first time in 2016 and temperatures near the glacier face are now the coldest in 40 years.
"At first, we did not believe it," JPL glaciologist Ala Khazendar said in a statement. "We thought pretty much that Jakobshavn would continue as if nothing had happened in the last 20 years."
Scientists believe that a climate pattern called "North Atlantic Oscillation" results in the observed ocean temperature changes along the west coast of Greenland. The same climate pattern has brought unexpected species to British waters in recent years.
The NAO model is reversed every five to 20 years. When he returns again, Jakobshavn will probably begin to clear up and back off.
"Jakobshavn stands out temporarily from this climate, but in the long term, the oceans are warming up," said Josh Willis, chief scientist at NASA's Oceans Melting Greenland Mission in Greenland. "And seeing the oceans have a huge impact on the glaciers is bad news for the Greenland icecap."
Several factors influence the melting rates of a glacier, including air temperature and its internal structure. However, scientists at the OMG mission want to better understand the influence of ocean currents and temperature on coastal glaciers.
As Jakobshavn's latest observations suggest, oceanic regimes have a significant impact on glacier behavior.
Scientists from the OMG mission recently returned to Greenland for another round of aerial surveys. The data collected will help researchers to more accurately characterize the effects of water temperature, as well as ocean waves and currents, on the lower surface of Greenland's melting glaciers.
"The OMG mission deployed new technologies that allowed us to observe a natural experiment, such as in a laboratory, where variations in ocean temperature were used to control the flow of a glacier," he said. said scientist Tom Wagner of NASA. "Their discoveries – particularly on how quickly the ice reacts – will be important in projecting sea level rise in the near and distant future."
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