What was first captured on satellite, is now capturing the attention of scientists. Extreme melting of Greenland's surface ice cover.
The photo above shows the extent of surface melt over Greenland’s ice sheet on July 8 (left) and July 12 (right).
Measurements from three satellites showed that on July 8, about 40 percent of the ice sheet had undergone thawing at or near the surface. Just a few days later, the melting had dramatically accelerated and an estimated 97 percent of the ice sheet surface had thawed by July 12.
Researchers have not yet determined whether this extensive melt event will affect the overall volume of ice loss this summer and contribute to sea level rise.
The Greenland melting came at the same time of the unusually large dome of warm air over Greenland. The ridge has dominated that region since the end of May.
Even the area around Summit Station in central Greenland, which at 2 miles above sea level is near the highest point of the ice sheet, showed signs of melting. Such pronounced melting at Summit and across the ice sheet has not occurred since 1889, according to ice cores analyzed by Kaitlin Keegan at Dartmouth College in Hanover, N.H. A National Oceanic and Atmospheric Administration weather station at Summit confirmed air temperatures hovered above or within a degree of freezing for several hours July 11-12.
"Ice cores from Summit show that melting events of this type occur about once every 150 years on average. With the last one happening in 1889, this event is right on time," says Lora Koenig, a Goddard glaciologist and a member of the research team analyzing the satellite data. "But if we continue to observe melting events like this in upcoming years, it will be worrisome."