MOSCOW - Von P. Walden's research made the cover of the April 4 issue of Nature after he and his team recorded a scientific anomaly not witnessed since 1889.
Walden and eight other scientists planned to take some basic measurements of the atmosphere and clouds at Summit Station in Greenland last summer.
What the team saw was weather that bumped 97 percent of the surface of the vast Greenland Ice Sheet to above-freezing temperatures. The ice sheet covers most of the island - roughly 656,000 square miles, according to the National Snow and Ice Data Center in Colorado.
Clouds over Greenland were the perfect thickness to accelerate melting: They were thin enough to allow sunlight to pass through but thick enough to trap heat near the surface.
Walden said the researchers plugged their data into a model to test cloud thickness as a factor.
"The model and the measurements agreed, and then we were able to determine the clouds were key," he said.
Clouds are one of the great uncertainties in climate modeling, Walden said. But understanding the data is important for scientists who have offered a range of projections for how quickly and how much the Earth might warm.
They have a similar range of projections for how quickly Greenland's ice sheet could melt. Today, the ice pack is said to be melting at the rate of the worst projection.
"The ice melt of Greenland is contributing significantly to sea water rise," Walden said.
Elevated sea levels could lead to the potential loss of coastal lands and communities - it's one of the greatest concerns when people discuss global warming. The Greenland ice sheet holds enough water to increase ocean levels nearly 22 feet, scientists say.
"This work is a major contribution to understanding the long-term implications of climate change in Greenland," said Jack McIver, the University of Idaho's vice president for research.
Walden said the phenomenon has not occurred since 1889 at Summit, a field research station supported by the National Science Foundation at about 10,000 feet above sea level.
"That's the highest elevation at the ice sheet," Walden said.
It was the team's ability to determine exactly what caused the melting that made Nature, a top scientific journal, decide to publish the article and put it on the cover, he said.
This is Walden's first article in Nature. He said that's a prestigious and difficult task to accomplish, even without being featured on the cover. It took two rounds of peer review to be accepted, and then his team was asked for cover art submissions, he said.
"I kind of did some shouting and some dancing," Walden said. "I thought we had a good shot because it's a great picture."
The Nature cover photo, taken by professor Brant Miller, shows the cloud cover at Summit.
UI doctoral student Chris Cox was a co-author of the article.
Walden, originally from near Kalispell, Mont., has done research in the Arctic and Antarctica. He said he really got interested in the Earth's atmosphere as a graduate student at the University of Washington and had the opportunity to do research at the South Pole.
"I've been hooked ever since," he said.