While this finding is surprisingly and temporarily good news for the glacier and limits its contribution to sea-level rise, the reason for ice accumulation in the long run could be catastrophic.
Jakobshavn had a remarkably constant thinning for two decades Scientists believed that they would continue, if not accelerate, due to large-scale warming of the polar atmosphere and oceans. However, this speed slowed dramatically in 2014, and the glacier actually thickened between 2016 and 2017 and then between 2017 and 2018 to the study.
"At first we did not believe it," said Ala Khazendar, the leading NASA scientist in the study. Jakobshavn Isbrae, the full name of the glacier located on the West Greenland coast, has been the fastest flowing and largest glacier in the last 20 years with loss of ice in Greenland ̵
In fact, the meltdown of this single glacier, following NASA's Khazendar, has helped the world's oceans increase by an average of one millimeter between 2000 and 2010.
And although Jakobshavn has gained ice at the lowest levels where it enters the sea, it has still contributed to sea-level rise, as the speed at which it melts in the sea is still greater than that Speed at which ice accumulates on the glacier, the researchers say.
The glacier controls a basin with enough ice that, when completely melted, would raise the oceans by about 2 feet.
It is this threat. and the rapid speed at which Jakobshavn has shredded ice in recent decades has led scores of scientists to the icy shores, making the glacier one of the world's most if not the most studied glaciers.
Cooler water cooled the advance of Jakobshavn
. 19659002] Between 2014 and 2016, waters penetrated up to 2 degrees Celsius in the Disko Bay, where the Jakobshavn Glacier goes into the water.
Researchers believe that the slowdown is related to a natural climate change in the northern hemisphere, the so-called North Atlantic Oscillation (NAO), which may warm or cool the northern parts of the Atlantic Ocean over several years (not too unlike the effects). El Nino and La Nina can have the temperatures of the Pacific Ocean).
Through detailed observations, Khazendar and his team were able to track down this cooler water from the open North Atlantic to Disko Bay and found that the timing was the same as the glacier change to ice.
"Over the past two to three years, the role of the ocean has been dominant," Khazendar said.
But in the late 1990s, much warmer water penetrated the bay that melted the ice shelf that protected Jakobshavn glacier, which unleashed the unprecedented melting of the glacier for the next two decades.
"It's like a 20-year experiment," Khazendar said.
He said that the dramatic response of the glacier to variations in sea temperature is forcing scientists to reevaluate how sensitive glaciers are to slight changes in the marine climate.
Reprieve, no resurrection
The cooling of the North Atlantic is a blow to the radar, a local effect that eventually gets warmer when the NAO vibration returns. This happens simultaneously with climate change, which increases the thermostat on the Earth's oceans.
"This is a postponement," Khazendar told CNN about the recent thickening of the Jakobshavn Glacier, "no resurrection."
Scientists warn against leaking the news of one of the world's most critical glaciers and unexpectedly gaining ice cream.
"The chances of this going on are, in my opinion, very low," said Eric Rignot, a glaciologist from UC Irvine and senior research scientist at NASA's JPL, who was not part of the JPL study. "It's only a matter of time before the glacier thins again – maybe this summer, maybe next year."
The results of this study show that glaciers are extremely vulnerable to hot and cold temperatures, and this is not good news for the future.
Most of the heat from global warming goes directly to the oceans, studies show that this is more than 90%, which causes the global warming of the oceans to increase each year.
"Next time, when the warm water returns to Jakobshavn, they will be even warmer," Khazendar said.