The 1979-2005 Greenland ice sheet melt extent from passive microwave data using an improved version of the melt retrieval XPGR algorithm

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 x 10(7) km(2). An improved version of the cross-polarized gradient ratio (X...

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Bibliographic Details
Published in:Geophysical Research Letters
Main Authors: Fettweis, Xavier, van Ypersele de Strihou, Jean-Pascal, Gallee, H., Lefebre, F., Lefebvre, Wouter
Other Authors: UCL - SC/PHYS - Département de physique
Format: Article in Journal/Newspaper
Language:English
Published: Amer Geophysical Union 2007
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Online Access:http://hdl.handle.net/2078.1/37731
https://doi.org/10.1029/2006GL028787
Description
Summary: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 x 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.