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The 1979–2005 Greenland ice sheet melt extent from passive microwave data using an improved version of the melt retrieval XPGR algorithm
Author(s) -
Fettweis X.,
van Ypersele J.P.,
Gallée H.,
Lefebre F.,
Lefebvre W.
Publication year - 2007
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 - 10.1029/2006gl028787
Subject(s) - greenland ice sheet , snow , snowpack , ice sheet , climatology , geology , albedo (alchemy) , atmospheric sciences , ice sheet model , ablation zone , brightness temperature , satellite , environmental science , cryosphere , microwave , sea ice , ice stream , geomorphology , art , glacier , physics , quantum mechanics , performance art , art history , aerospace engineering , engineering
Analysis of passive microwave satellite observations over the Greenland ice sheet reveals a significant increase in surface melt over the period 1979–2005. Since 1979, the total melt area was found to have increased by +1.22 × 10 7 km 2 . An improved version of the cross‐polarized gradient ratio (XPGR) technique is used to identify the melt from the brightness temperatures. The improvements in the melt retrieval XPGR algorithm as well as the surface melt acceleration are discussed with results from a coupled atmosphere‐snow regional climate model. From 1979 to 2005, the ablation period has been increasing everywhere over the melt zone except in the regions where the model simulates an increased summer snowfall. Indeed, more snowfall in summer decreases the liquid water content of the snowpack, raises the albedo and therefore reduces the melt. Finally, the observed melt acceleration over the Greenland ice sheet is highly correlated with both Greenland and global warming suggesting a continuing surface melt increase in the future.