CLIMATEWIRE | Ominous clouds rippled overhead, and scientist Jason Field raced to succeed in shelter earlier than the rain hit.
Field, a glaciologist with the Geological Survey of Denmark and Greenland, had been tenting with colleagues on the Greenland ice sheet final Friday when the climate started to show.
Because the crew rushed to get off the ice, Field was struck by how heat the air felt on his face. It reminded him of scorching Chinook winds that sweep via Colorado within the wintertime, melting snow and ice of their path.
He was proper to search out it foreboding. Over the subsequent few days, the nice and cozy climate triggered a significant melting episode in Greenland — a shocking occasion for September, which generally marks the tip of the ice sheet’s soften season.
Through the episode’s peak Saturday, round 12 billion tons of ice melted and ran off into the ocean. Scientists estimate that greater than 200,000 sq. miles of the ice sheet — an space larger than California — had been affected by the melting.
Based on Xavier Fettweis, a local weather scientist on the College of Liège in Belgium, the episode probably ranks amongst Greenland’s prime 10 highest runoff occasions. And it’s probably the strongest September soften occasion on file.
Seeing such a powerful soften occasion so late within the 12 months, Fettweis added in an e-mail, is “distinctive.”
The melting Greenland ice sheet is a prime concern for local weather scientists, and for human society as a complete, because the Earth warms. Greenland presently pours about 250 billion tons of ice into the ocean annually, within the type of each crumbling glaciers and floor melting. It’s the planet’s prime contributor to rising sea ranges.
Summer season is Greenland’s important melting season. When ice melts on the floor, a number of the liquid water trickles again into the porous snow on prime of the ice sheet, the place it refreezes. However a few of it runs into the ocean, the place it provides to rising seas. These runoff occasions are a significant preoccupation for scientists keeping track of sea ranges.
Massive melting occasions are inclined to exacerbate the runoff downside — past the issue of extra liquid. Previous a sure level, porous snow fills up and there isn’t area for any extra liquid water to trickle in.
And late-season soften occasions can prime the ice sheet for extra runoff the next summer time, Fettweis warned. With winter approaching, the liquid water refreezes quicker and varieties onerous lenses on the floor of the ice sheet. These lenses could make it harder for subsequent 12 months’s meltwater to penetrate the floor, forcing it to run off into the ocean as an alternative.
This 12 months’s soften season had been comparatively modest till the September episode. It was punctuated by a single “warmth ripple” in July, in accordance with the Nationwide Snow and Ice Knowledge Heart, which brought on a reasonable soften surge throughout the ice sheet.
However the ice sheet has seen some extraordinary melting in different current summers. The 2019 season introduced a few of its strongest melting, and highest mass losses, on file (Climatewire, Aug. 2, 2019). And 2021 noticed a number of in depth soften occasions in July and August.
Throughout final 12 months’s August occasion, scientists noticed rain falling at Greenland’s Summit Station — a high-altitude analysis station positioned practically 2 miles above sea stage — for the primary time in recorded historical past. Temperatures there not often rise above freezing.
Scientists have warned these sorts of occasions might develop extra frequent and extra extreme because the area retains warming — growing Greenland’s contributions to international sea-level rise.
Sturdy September soften occasions are nonetheless unusual. However that will change within the coming years. Based on Fettweis, research recommend that Greenland’s soften season will lengthen in a hotter local weather, and late-season occasions might occur extra typically.
The newest melting occasion seems to have slowed after peaking over the weekend. However the episode was immortalized by artist Mette Hansgaard, who had adopted Field and the opposite scientists into the sphere for a couple of days to expertise the ice sheet — and its ongoing response to local weather change — for herself.
As plump raindrops started to fall from the sky final Friday, Hansgaard paused to seize the panorama on her canvas.
“It’s raining right here, so each time the colours get moist, the colours begin to run,” she stated as she painted. “So the rain and the climate impacts the portray the identical manner because the climate impacts ice, in a manner.”
Reprinted from E&E Information with permission from POLITICO, LLC. Copyright 2022. E&E Information supplies important information for vitality and setting professionals.
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