U.S. atmospheric scientists say satellite data indicates northern Greenland experienced a record number of melting days this summer.

City College of New York Assistant Professor Marco Tedesco said the northern part of the Greenland ice sheet experienced extreme snowmelt during this summer, with large portions of the area subject to record melting days.

Tedesco and his team said they based their conclusion on an analysis of microwave brightness temperature recorded by the Special Sensor Microwave Imager on the F13 satellite.

"Having such extreme melting so far north, where it is usually colder than the southern regions, is extremely interesting," Tedesco said. "In 2007, the record occurred in southern Greenland, mostly at high elevation areas, where in 2008 extreme snowmelt occurred along the northern coast."

He said melting in northern Greenland lasted up to 18 days longer than previous maximum values. And he said the melting index -- the number of melting days times the area subject to melting -- was three times greater than the 1979-2007 average.

The findings are reported in the Oct. 6 edition of "EOS," a weekly newspaper published by the American Geophysical Union.