NASA - Greenland Experiencing More Days With Snow Melt - Melting At Higher Altitudes - AFP

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In 2006, Greenland experienced more days of melting snow and at higher altitudes than average over the past 18 years, according to a new NASA-funded project using satellite observations. Daily satellite observations have shown snow melting on Greenland's ice sheet over an increased number of days. The resulting data help scientists understand better the speed of glacier flow, how much water will pour from the ice sheet into the surrounding ocean and how much of the sun's radiation will reflect back into the atmosphere.

"We now have the ability to monitor melting snow on Greenland's ice sheet on a daily basis using sensors on satellites measuring the electromagnetic signal naturally emitted by the ice sheet," said Marco Tedesco, research scientist at the Joint Center for Earth Systems Technology cooperatively managed by NASA's Goddard Space Flight Center, Greenbelt, Md., and the University of Maryland at Baltimore County, Baltimore.

"The sensors detected that snowmelt occurred more than 10 days longer than the average over certain areas of Greenland in 2006," said Tedesco, who is lead author of the study, which appears in the May 29 issue of the American Geophysical Union's Eos. Tedesco applied a new method for detecting melting snow to data from the Special Sensor Microwave Imaging radiometer (SSM/I) flying aboard the Defense Meteorological Satellite Program spacecraft. The sensor can see through clouds and does not require sunlight to make measurements, providing researchers with multiple daily observations. Tedesco has updated the results annually since 1988, which has enabled him to analyze trends in the duration of snowmelt and extent over specific areas of Greenland.

To understand why these trends are important to track, Tedesco explained one of the consequences of melting snow. "Although wet and dry snow look similar at first glance, wet and re-frozen snow absorb more of the sun's radiation, reflecting only 50-60 percent back into the atmosphere. Dry snow, on the other hand, reflects about 85 percent of the sun's radiation," he said. "In other words, melting snow absorbs three to four times as much energy as dry snow, greatly affecting Earth's energy budget."

EDIT

http://www.terradaily.com/reports/Days_Of_Snow_Melting_On_The_Rise_In_Greenland_999.html

[phantom power]

1. Aaah. My morning helping of nutritious positive feedbacks.

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2. Good, good for you and right in line with the physical world

They're Thermodynamically Delicious!