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Greenland ice sheet melt from MODIS and associated atmospheric variability
Author(s) -
Häkkinen Sirpa,
Hall Dorothy K.,
Shuman Christopher A.,
Worthen Denise L.,
DiGirolamo Nicolo E.
Publication year - 2014
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2013gl059185
Subject(s) - greenland ice sheet , moderate resolution imaging spectroradiometer , climatology , atmospheric sciences , geology , environmental science , anomaly (physics) , ridge , ice sheet , subtropics , atmospheric temperature , satellite , geomorphology , paleontology , physics , condensed matter physics , fishery , engineering , biology , aerospace engineering
Daily June‐July melt fraction variations over the Greenland ice sheet (GIS) derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) (2000–2013) are associated with atmospheric blocking forming an omega‐shape ridge over the GIS at 500 hPa height. Blocking activity with a range of time scales, from synoptic waves breaking poleward (<5 days) to full‐fledged blocks (≥5 days), brings warm subtropical air masses over the GIS controlling daily surface temperatures and melt. The temperature anomaly of these subtropical air mass intrusions is also important for melting. Based on the years with the greatest melt (2002 and 2012) during the MODIS era, the area‐average temperature anomaly of 2 standard deviations above the 14 year June‐July mean results in a melt fraction of 40% or more. Though the summer of 2007 had the most blocking days, atmospheric temperature anomalies were too small to instigate extreme melting.