Alaska changes seen as no snow job

A team of scientists presented data this month suggesting that as the state of Alaska has warmed up extremely rapidly in recent years, snowfall in the iconic Denali National Park has increased dramatically during the era of human-driven global warming.

The researchers from Dartmouth College; the University of Maine, Orono; and the University of New Hampshire set up a camp at 13,000 feet atop Mount Hunter, within view of Denali.

There, they drilled into the snow to extract lengthy cores of ice that provided a historical record of snowfall patterns going back more than 1,000 years — and found a marked change over the past 150 years or so.

“We were shocked, frankly, at just how much snowfall had increased,” said Erich Osterberg, a Dartmouth researcher who was one of the study’s authors.

The ice cores showed an enormous upswing in the rates of snowfall beginning around the Industrial Revolution in the 19th century, when humans began burning fossil fuels to produce energy in large quantities.

The increase over time represented more than a doubling in the amount of snow.

“Snowfall before the Industrial Revolution averaged about 8 feet of fresh snow a year at this site, and now we get over 18 feet of fresh snow,” Osterberg said.

“We can say confidently that the amount of snowfall we see today has never been seen previously during that whole 1,200-year record,” Osterberg said. “That we are way outside the range of what was natural conditions before the Industrial Revolution.”

Climate change increases the volume of precipitation because a warmer atmosphere holds more water vapor.

But it isn’t supposed to increase it this much.

The researchers attribute part of the snowfall increase to the atmosphere retaining more water vapor.

But they also say that the warming up of the tropical Pacific Ocean changed the atmospheric patterns, leading more storms to track across Alaska — thus accounting for a potent one-two punch.

But Osterberg said Alaska’s glaciers are still widely retreating at lower altitudes — even though they are being fed with heavy volumes of snow at high altitudes, where there is little melt.

Two years ago, scientists reported that Alaska’s glaciers were losing 75 billion tons of ice annually.

The new work was published in Nature Scientific Reports.