Forget global warming, Alaska is headed for an ice age

Posted: December 25, 2012 in 2012, world news
Tags: , , , , , , , , , , ,

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Alaska is going rogue on climate change.

Defiant as ever, the state that gave rise to Sarah Palin is bucking the mainstream yet again: While global temperatures surge hotter and the ice-cap crumbles, the nation’s icebox is getting even icier.

That may not be news to Alaskans coping with another round of 50-below during the coldest winter in two decades, or to the mariners locked out of the Bering Sea this spring by record ice growth.

Then again, it might. The 49th state has long been labeled one of the fastest-warming spots on the planet. But that’s so 20th Century.

In the first decade since 2000, the 49th state cooled 2.4 degrees Fahrenheit.

Widespread warming

That’s a “large value for a decade,” the Alaska Climate Research Center at the University of Alaska Fairbanks said in “The First Decade of the New Century: A Cooling Trend for Most of Alaska.”

The cooling is widespread — holding true for 19 of the 20 National Weather Service stations sprinkled from one corner of Alaska to the other, the paper notes. It’s most significant in Western Alaska, where King Salmon on the Alaska Peninsula saw temperatures drop most sharply, a significant 4.5 degrees for the decade, the report says.

 The new nippiness began with a vengeance in 2005, after more than a century that saw temperatures generally veer warmer in Alaska, the report says. With lots of ice to lose, the state had heated up about twice as fast as the rest of the planet, in line with rising global greenhouse gas emissions, note the Alaska Climate Center researchers, Gerd Wendler, L. Chen and Blake Moore. After a “sudden temperature increase” in Alaska starting in 1977, the warmest decade on record occurred in the 1980s, followed by another jump in the 1990s, they note. The third warmest decade was the 1920s, by the way.
very-cold

Too chilly for king salmon?

But now comes cooling. Researchers blame the Decadal Oscillation, an ocean phenomenon that brought chillier surface water temperatures toward Alaska. Some contend the Pacific Decadal Oscillation is harming the state’s king salmon runs, too.

One effect of the oscillation is to weaken the Aleutian Low — a storm-breeding center known for spitting out winter tempests that help regulate weather in the Lower 48. With that low-pressure center above the Aleutians weakened, polar storms raking Alaska from the north linger longer.

People have noticed the new chill in King Salmon, but slightly colder  temperatures don’t bother you much when you’re already bundled up for 20-below, said Don Hatten, the National Weather Service forecaster there. Most noticeable was that for the first time last year, the Bering Sea ice shelf extended south nearly to the edge of the Alaska Peninsula, he said.

The single exception to Alaska’s cooling trend came in Barrow along North Slope, where the mercury rose as it has across most of the Arctic. That’s because that northernmost slice of Alaska is secluded from the rest of the state by the Brooks Range, researchers say. Temperatures for the decade were 3.1 degrees higher in Barrow. That trend continued earlier this year, with weeks of above average temperatures in Barrow, apparently driven in part by Arctic Ocean ice melting.

Some like it cold

Will Alaska’s frigid spell last long? The researchers don’t know. The report notes, however, that Alaska endured three decades of relative cold starting in the mid-1940s. Many Alaskans pray the current cold stretch abates sooner.

 

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