MELTDOWN: Greenland has experienced an unprecedented meltdown so far this year, and there are still four more weeks of summer.
Image: NASA Goddard Photo and Video
Greenland's massive ice sheet is melting at a record pace this summer.
By Aug. 8, this year's summer melt had shattered the record set in 2010, according to a new analysis of satellite data by glaciologist Marco Tedesco of the City University of New York.
With four weeks to go before the end of Greenland's melt season, Tedesco said this year could end up being "a goliath," far outranking any other in the 30-year satellite record.
Areas that don't normally melt or melt for just a few days each summer appear to have lost significant amounts of ice this year. That helped drive up this year's "cumulative melt index," a measure that takes into account the spatial extent and duration of thawing across the ice sheet.
"On the east coast, the west coast, at high elevations, in the north, there was a disproportionate amount of melting, both in terms of extent and duration, with respect to previous years," Tedesco said.
Thomas Mote, a climatologist at the University of Georgia, said his independent analysis of the same Air Force satellite data Tedesco used confirms that Greenland has broken its seasonal melt record this year.
The news comes on the heels of NASA's announcement that Greenland endured an unusually widespread, intense burst of surface melting for a few days in mid-July. During that brief period, an astonishing 97 percent of the surface of Greenland's ice sheet showed signs of thaw -- covering a larger area than any melting event since satellite records began 30 years ago (ClimateWire, July 25).
That was followed by a similar but shorter event in late July. While those incidents were unusual, their contributions to the record-breaking summer melt were small, Tedesco said.
"If you weigh an elephant with a leash and without a leash, the weight changes slightly, but it is still very heavy," he explained.
Warm temperatures not the only culprit
More important was persistent melting through June and July in areas that don't normally thaw much. Some high elevations in southern Greenland that usually melt for just a few days experienced 30, 40 or even 50 days of melting this summer.
Researchers believe that high temperatures kick-started that melting, but other factors helped intensify it. Warming removed layers of snow that covered the ice sheet's surface, leaving bare ice behind. Because that bare ice is less reflective that snow, it absorbs more heat from the sun, spurring even more melting.
According to Ohio State University glaciologist Jason Box, the Greenland ice sheet is less reflective this year than it has been since record-keeping began in 2000.
Still, researchers are hesitant to predict how Greenland's ice will fare over the remaining weeks of the summer melt season, which normally ends in mid-September.
"It's very hard to say what will happen within a month," Tedesco said. "If things keep going like this, melting will be considerable."
But Greenland's ice is not the only portion of the Arctic experiencing a record-breaking thaw this year. The region's sea ice cover is at a record low for this time of year, according to the National Snow and Ice Data Center -- on pace to set a new annual low in mid-September.
Just as removing snow from the surface of the ice sheet and exposing the bare ice below helps speed melting, replacing sea ice with dark ocean water helps trap heat. That warmth cycles back into the atmosphere each fall, when the amount of sunlight dips and sea ice reforms.
"It's a perfect storm in the Arctic," Tedesco said. "There are all these factors playing together in favor of continuous melting. It really stands out from other years."
Reprinted from Climatewire with permission from Environment & Energy Publishing, LLC. www.eenews.net, 202-628-6500
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8 Comments
Add CommentDid they get a gold medal?
Reply | Report Abuse | Link to thisI am starting to think SA may not be at least checking on claims. This was already debunked because it is a repeating occurrence every 150 years as proven by ice core samples.
Reply | Report Abuse | Link to thisMaking the claim this is unusual, unprecedented or caused by us evil humans is simply junk science. This happens every 150 years and it has nothing at all to do with the current evil human caused global warming.
This is yet another example of so called scientists trying to create fact out of assumption or simply rigging data. The last 30 years is meaningless but the junk scientists try to make it seem like it is, resulting in junk conclusions like greenland is melting and it has never happened before.
Priddseren,
Reply | Report Abuse | Link to thisSo much wrong with your post.
A. This article is discussing the TOTAL melt for the SEASON. The SEASONAL melt record has been broken.
B. What you are thinking of is the extent and altitude melt record that was set in July.
C. What is going on with the July event is that it should not really be characterized as occurring every 150 years, but that the mean average gives a figure of 150 years. Yet, that does not quite capture the reality either. Here is a paleoclimatic graph:http://www.gisp2.sr.unh.edu/DATA/alley1.html of the melt years for central Greenland. Note that there is not really a 150 year periodic melt. Here is the paper that that graph and figure you squeal about comes from:
Variations in melt-layer frequency in the GISP2 ice core:
implications for Holocene summer temlperatures in
central Greenland](http://www.igsoc.org/annals.old/21/igs_annals_vol21_year1995_pg64-70.pdf
>Abstract: The rare melt features in the GISP2, central Greenland deep ice core have decreased in frequency over the most recent 7000 years. Calibration of this change in melt frequency against modern spatial variation of melt frequency and temperature in central Greenland, and against modern temporal variability of temperatures in central Greenland, indicates that mean mid-summer temperatures have cooled over the most recent 7000 years, probably by slightly more than I C if variability of summer temperatures has not changed.|
So in short, you have in the space of three paragraphs have managed to squeeze in two factual errors and one conspiracy theory. Par for the course.
Priddseren is matching the Greenland meltdown with a near-total brain liquifaction of his own. Nowhere in the article is there any reference to human-caused global warming. Usually a straw man is crafted more carefully, but then we have come to expect fairly limited intellectual exercise from that side. It's fun to watch them try to form a thought, though, especially if they have missed the latest Rush Limbaugh episode and thus have an empty septic tank of nonsense from which to draw.
Reply | Report Abuse | Link to thisJUst think of all the pre-ice fossils to be found!
Reply | Report Abuse | Link to thisand I assume you do not expect the clown to actually go and review the links and read what you wrote right?
Reply | Report Abuse | Link to thisI mean he already KNOWS you are wrong. So what purpose would it serve him to read what you say. LOL
priddseren's comments often remind me of this for some reason. http://www.youtube.com/watch?v=5NNOrp_83RU
Reply | Report Abuse | Link to thisLose the facetwit floater!
Reply | Report Abuse | Link to this