- October 8, 2008
SATELLITE DATA REVEALS EXTREME SUMMER SNOWMELT IN NORTHERN GREENLAND,
CCNY PROFESSOR SAYS
The northern part of the Greenland ice sheet experienced extreme
snowmelt during the summer of 2008, with large portions of the area
subject to record melting days, according to Dr. Marco Tedesco,
Assistant Professor of Earth & Atmospheric Sciences at The City
College of New York (CCNY), and colleagues. Their conclusion is based
on an analysis of microwave brightness temperature recorded by the
Special Sensor Microwave Imager (SSM/I) onboard the F13 satellite.
"Having such extreme melting so far north, where it is usually colder
than the southern regions is extremely interesting," Professor
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."
Melting in northern Greenland lasted up to 18 days longer than
previous maximum values. The melting index, i.e. the number of
melting days times the area subject to melting) was three times
greater than the 19792007 average, with 1.545106 square kilometers
x days. The findings were reported in the October 6 edition of "EOS,"
a weekly newspaper published by the American Geophysical Union.
"The results obtained from SSM/I are consistent with the outputs of
the MAR (Modèl Atmosphérique Régional) regional climate model, which
indicated runoff 88 percent higher than the 1979 2007 mean and
close to the 2007 value," Professor Tedesco noted. In addition,
analysis of ground measurements from World Meteorological
Organization automatic weather stations located close to where the
record snowmelt was observed indicate surface/air maximum
temperatures up to 3° Celsius above average.
The snowmelt and temperature anomalies occurred near Ellesmere
Island, where several ice shelf break-ups were observed this summer.
The region where the record melting days were recorded includes the
Petermann glacier, which lost 29 square kilometers in July.
Professor Tedesco and his colleagues are currently analyzing possible
causes for the high snowmelt in northern Greenland. High surface
temperatures are, so far, the most evident factor. However other
factors, such as solar radiation, could play a role, as well, he
"The consistency of satellite, model and ground-based results
provides a basis for a more robust analysis and synthesis tool,"
Professor Tedesco added. Next June, he and his colleagues plan to
conduct field work in northern Greenland.
City College of New York