A large Greenlandic glacier, which was one of the fastest shrinking ice and snow masses on the ground, is growing again, a new NASA survey find.
Jakobshavn (YA-cob-shawv) the glacier around 2012 was returning about 3 km and thinning almost 40 meters annually. But it began to grow again at the same rate over the past two years, according to a study in Monday's natural geoscience. Investigators and outside researchers believe this is temporary.
"It was a little surprising. We were very used to a rail system," said Jason Box, Geological Survey for Denmark and Greenland. "The good news is that it is a reminder that it doesn't necessarily go so fast. But it goes."
The box, which was not part of the studio, said that Jakobshavn is "possibly the most important Greenlandic glacier because it emits the most ice in the northern hemisphere. For the whole of Greenland it is king."
A natural cyclical cooling of the North Atlantic waters probably caused the glacier to turn the course, said the study director author Ala Khazendar, a NASA glaciologist on the oceans Melting Greenland (OMG) project. Khazendar and colleagues say this coincides with a flip of North Atlantic oscillation ̵
The water in Disko Bay, where Jakobshavn hits the sea, is about 2 degrees Celsius cooler than a few years ago, said study authors.
Although it is "good news" temporarily, it is bad news in the long run because it tells scientists that sea temperature is a major player in glacier voyages and progress than previously thought, NASA climate scientist Josh Willis, a study co-author, said.
Over the decades, the water has been and will heat up man-made climate change, he said, noting that about 90 percent of the heat trapped by greenhouse gases enters the oceans.
"In the long term, we will probably have to raise our sea level predictions again," Willis said.
Think of ocean temperatures near Greenland as an escalator that slowly rises from global warming, Khazendar said. But the natural North Atlantic oscillation is sometimes like jumping down a few steps or jumping up a few steps. The water can get cooler and have effects, but in the long run it gets warmer and the melt gets worse, he said.
Four foreign researchers said the study and the results were reasonable.
Ian Joughin, the University of Washington ice researcher who was not part of the study and predicted such a change seven years ago, said it would be a "serious mistake" to interpret the latest data as conflicting climate science. 19659002] What happens, says Joughin, "is a very temporary blip. Slowdowns occur in the stock market, but generally the long-term path is up. is really the same. "