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4806Greenland Melting

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  • Mike Neuman
    Oct 26, 2008
      October 8, 2008


      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 1979–2007 average, with 1.545•106 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.



      Ellis Simon
      City College of New York