Study links Greenland melting with 'Arctic amplification'

"If loss of sea ice is driving changes in the jet stream, the jet stream is changing Greenland, and this, in turn, has an impact on the Arctic system as well as the climate," explained researcher Marco Tedesco.
By Brooks Hays   |   June 9, 2016 at 10:14 AM
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NEW YORK, June 9 (UPI) -- New research links Greenland's 2015 record temperatures and melting with the phenomenon known as Arctic amplification.

The phenomenon describes the advanced rate of warming in the Arctic, as compared to the rest of the planet. Climate scientists and their models have long predicted a unique feedback loop that encourages accelerated warming in the Arctic, and the hard data supports the theory. The Arctic is warming twice as fast as the rest of the planet.

Scientists remain uncertain about what effect amplification will have on the atmosphere and broader climate patterns.

Simulations suggest that as the temperature gradient between the poles and tropics weakens, the jet stream will slow and meander more dramatically -- like a river snaking across a delta. Wider wind current swings are expected to push warm, moist air farther north.

The new study, published this week in the journal Nature Communications, suggests Greenland warming and Arctic amplification are already encouraging these outcomes. In the summer of 2015, scientists say the jet stream swung farther north than it ever had before at that time of year.

"How much and where Greenland melts can change depending on how things change elsewhere on earth," lead study author Marco Tedesco, a research professor at Columbia University's Lamont-Doherty Earth Observatory, said in a news release.

"If loss of sea ice is driving changes in the jet stream, the jet stream is changing Greenland, and this, in turn, has an impact on the Arctic system as well as the climate," added Tedesco, also an adjunct scientist at NASA Goddard Institute for Space Studies. "It's a system, it is strongly interconnected and we have to approach it as such."

The new study doesn't blame Arctic amplification explicitly for Greenland's 2015 record melt runoff and surface temperatures. But it does offer evidence of exactly what scientists and Arctic amplification models predicted.

The researchers documented key components of the feedback loop, pointing out that diminished snow totals and higher levels of melting depressed Greenland's reflectivity, or albedo, allowing its surface to absorb more of the sun's energy.

The record-breaking melting was encouraged by a far-reaching jet stream, which brought clear skies and warm air to the northern half of the island. Scientists say such high-pressure systems are likely to become more common as the planet warms and Arctic amplification continues.

"The significant increase in Greenland high-pressure blocking that has occurred in the last 20 to 30 years is clearly related to recent record warming over the region, as well as jet-stream changes," said study co-author Edward Hanna, a climate scientist at the University of Sheffield. "This makes it more likely than not that within the next five to 10 years we will witness further record Greenland melt events like in 2012 and 2015."

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