Summer Snow, Southerly Gulf Stream Keeping Greenland Somewhat Cool This Summer; No Long-Term Change

[hatrack]

Recent summers on the vast, white expanse of the Greenland ice sheet have featured some spectacular ice melt, including an alarming period in 2012 when nearly the whole surface showed signs of melt. But this summer has instead seen several bouts of snow, staving off a big summer melt. So what gives?


Meltwater lakes poke through a surface of fresh snow after a summer snowstorm in Greenland. The snow helped to briefly stymie summer melt.

While it may seem contradictory, those snows are actually something Greenland may see more of with global warming, as the atmosphere becomes primed to dump more heavy precipitation. And while that snow may insulate the ice sheet against major melt this year, focusing on one summer risks missing the forest for the trees. Because make no mistake, Greenland is still melting, dumping water into the ocean and causing global sea levels to steadily rise. “We’re still pumping a lot of ice” out to sea, Marco Tedesco, who studies Greenland at Columbia University’s Lamont-Doherty Earth Observatory, said.

As Arctic temperatures rise at about double the rate of the planet as a whole, Greenland’s surface has been melting at a steady clip, contributing about 30 percent of the foot of global sea level rise since 1900. And summer is prime melt season, when the sun’s rays beat down on the ice, causing meltwater to pool on the surface and drain down through the ice sheet and out to sea.

EDIT

While there were some bouts of melting earlier in the summer, the weather has since shifted. In recent weeks, summer snows have topped up that already unusually high snow load. Right now, the ice sheet’s surface has about 1.2 times the amount of mass than normal; at the same point in 2012, it had 1.2 times less than normal, Box said. Also inhibiting summer melt this year is the unusually southerly position of the jet stream, caused by a climate pattern called the North Atlantic Oscillation. “That’s keeping Greenland relatively cold,” Box said.

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http://www.climatecentral.org/news/despite-summer-snow-greenland-still-melting-21643

[Delphinus]

1. To go along with this story ...

http://grist.org/briefly/a-major-glacier-in-greenland-might-be-destabilizing/

A major glacier in Greenland might be breaking apart.

That’s the buzz this week in the polar science community after a big new iceberg emerged at Petermann Glacier in far northwest Greenland. Scientists first spotted an extensive network of cracks in Petermann earlier this year. The worry is that those cracks may widen during the next few weeks, the warmest part of the short Greenland summer. ... (more at link)

(posted 5 hours ago)

[hatrack]

2. Well, that's a switch!

Oh, and A68 (The Artist Formerly Known As Larsen C) has already moved about 1.5 miles from the remaining shelf, in the dead of the Austral winter, in about a week.

Good times!