Late-spring warmth brings a stunning new color to the dazzling white palette that dominates Greenland in the wintertime. The warmth means Greenland's melt season has started, and sapphire-blue pools will soon dot the ice sheet as its upper layer of snow and ice transforms into water.
In 2012, a rare combination of weird weather, unusual warmth and forest-fire soot pushed the summer melt into overdrive, according to several recent studies. Nearly the entire surface of the Greenland Ice Sheet melted, even in the cold, dry regions where Greenland's elevation soars above 10,000 feet (3,048 meters).
But in 2013, the summer melt returned to normal, according to the National Snow and Ice Data Center (NSIDC) in Boulder, Colorado. Almost half of the surface melted — ranking 14th in the 33 years since satellite tracking started in 1981.
Now, scientists are closely watching the 2014 summer thaw, to see if it will repeat 2012's impressive meltdown or return to the more mundane trend seen since 1981. So far, the signs point to an average year. [In Photos: Greenland's Melting Glaciers]
"We're not expecting anything exceptional for the next two weeks, but it's very difficult to look beyond that point," said Marco Tedesco, a Greenland melting expert at the City University of New York and a polar programs director for the National Science Foundation. "I think we will be able to make a good diagnosis by mid-July."
Some of the factors that led to a low surface melt in 2013 are still in play. The North Atlantic Oscillation, an atmospheric pressure pattern over the Atlantic Ocean, is still in a positive phase, as it was in 2013. The positive phase favors cooler conditions and summer snowfall across Greenland and warm, dry weather over Europe.
Also, meltwater has been slow to appear across the ice this year, Tedesco said.