* Winter storms in US, Europe linked to Arctic warmth
* Arctic is warming twice as quickly as lower latitudes
* Projections of rising seas should be revised upward
Deborah Zabarenko, Reuters AlertNet 21 Oct 10;
WASHINGTON, Oct 21 (Reuters) - The signs of climate change were all over the Arctic this year -- warmer air, less sea ice, melting glaciers -- which probably means this weather-making region will not return to its former, colder state, scientists reported on Thursday.
In an international assessment of the Arctic, scientists from the United States, Canada, Russia, Denmark and other countries said, "Return to previous Arctic conditions is unlikely."
Conditions in the Arctic are important because of their powerful impact on weather in the heavily populated middle latitudes of the Northern Hemisphere.
The heavy snows in the United States, northern Europe and western Asia last winter are linked to higher air temperatures over the Arctic, the scientists found.
"Winter 2009-2010 showed a new connectivity between mid-latitude extreme cold and snowy weather events and changes in the wind patterns of the Arctic, the so-called Warm Arctic-Cold Continents pattern," said the report, issued by the U.S. National Oceanic and Atmospheric Administration (NOAA).
The scientists found evidence of widespread Arctic warming, with surface air temperatures rising above global averages twice as quickly as the rate for lower latitudes, Jackie Richter-Menge of the U.S. Army Cold Regions Research and Engineering Laboratory.
Part of the reason for this is a process called polar amplification. Warming air melts the sun-reflecting white snow and ice of the Arctic, revealing darker, heat-absorbing water or land, spurring the effects of warming. This is further amplified by the action of the round-the-clock sunlight of Arctic summers, Richter-Menge said in a telephone briefing.
SNOWY PARADOX
Normally cold air is "bottled up" in the Arctic during winter months but in late 2009 and early 2010, powerful winds blew cold air from north to south instead of the more typical west to east pattern, said Jim Overland, an oceanographer at NOAA's Pacific Marine Environmental Laboratory in Seattle.
Overland saw this as a direct link between a warmer Arctic with less sea ice and weather in the middle latitudes, and he suggested it was likely to become more common as Arctic sea ice melts over the next 50 years.
This pattern has occurred only three times in the past 160 years, Overland said at the briefing.
"It's a bit of a paradox where you have overall global warming and warming in the atmosphere (that) actually can create some more of these winter storms," Overland said. "Global warming is not just warming everywhere. ... It creates these complexities."
Records tumbled in Greenland, where 2010 was the warmest year in 138 years in the island's capital city of Nuuk, and four big glaciers lost more than 10 square miles (25.90 sq km) each, said Jason Box of the Byrd Polar Research Center in Ohio.
"There's now really no doubt that glacier ice losses have not just increased but have accelerated," Box said. "Sea level rise projections for the future will again need to be revised upward."
The full report is available on the Internet at http://www.arctic.noaa.gov/reportcard/ .
(Editing by Will Dunham)
Sea ice melting as Arctic temperature rises
Randolph E. Schmid, Associated Press Yahoo News 21 Oct 10;
WASHINGTON – The temperature is rising again in the Arctic, with the sea ice extent dropping to one of the lowest levels on record, climate scientists reported Thursday.
The new Arctic Report Card "tells a story of widespread, continued and even dramatic effects of a warming Arctic," said Jackie Richter-Menge of the Cold Regions Research and Engineering Laboratory, a U.S. Army Corps of Engineers facility in Hanover, N.H.
"This isn't just a climatological effect. It impacts the people that live there," she added.
Atmospheric scientists concerned about global warming focus on the Arctic because that is a region where the effects are expected to be felt first, and that has been the case in recent years.
There was a slowdown in Arctic warming in 2009, but in the first half of 2010 warming has been near a record pace, with monthly readings over 4 degrees Celsius (7.2 Fahrenheit) above normal in northern Canada, according to the report card released Thursday.
Highlighting the immediate consequences of the warming, researchers said last winter's massive snowstorms that struck the Northeast and Mid-Atlantic states were tied to higher Arctic temperatures.
"Normally the cold air is bottled up in the Arctic," said Jim Overland of the National Oceanic and Atmospheric Administration's Pacific Marine Environmental Laboratory in Seattle. But last December and February, winds that normally blow west to east across the Arctic were instead bringing the colder air south to the Mid-Atlantic, he said.
"As we lose more sea ice it's a paradox that warming in the atmosphere can create more of these winter storms," Overland said at a news briefing.
There is a powerful connection between ice cover and air temperatures, Richter-Menge explained. When temperatures warm, ice melts. When reflective ice melts it reveals darker surfaces underneath, which absorbs more heat. That, in turn, causes more melting "and on the cycle goes," she said.
In September the Arctic sea ice extent was the third smallest in the last 30 years, added Don Perovich of the Army laboratory. He said the three smallest ice covers have occurred in the last four years.
Other findings included:
• Winter snow accumulation on land in the Arctic was the lowest since records began in 1966.
• Glaciers and ice caps in Arctic Canada are continuing to lose mass at a rate that has been increasing since 1987, reflecting a trend toward warmer summer air temperatures and longer melt seasons.
• The temperature in the permafrost is rising in Alaska, northwest Canada, Siberia and Northern Europe.
• Greenland in 2010 is marked by record-setting high air temperatures, ice loss through melting, and marine-terminating glacier area loss. The largest recorded glacier area loss observed in Greenland occurred this summer at Petermann Glacier, where a piece of ice several times larger than Manhattan Island broke away.
The report card, prepared by 69 researchers in eight countries, is issued annually by the U.S. National Oceanic and Atmospheric Administration.
In addition to Richter-Menge, Overland and Perovich, lead researchers included Mary-Louise Timmermans at Yale University; Jason Box, Ohio State University; Mike Gill, Environment Canada; Martin Sharp, University of Alberta, Canada; Chris Derksen, Environment; and D.A. Walker, Vladimir Romanovsky and Uma Bhatt, University of Alaska-Fairbanks.
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Online: http://www.arctic.noaa.gov/reportcard.
http://www.arctic.noaa.gov/detect/
