The Cryosphere www.the-cryosphere.net 1994-0416 1994-0424 4 3 2010 10.5194/tc-4-261-2010 http://www.the-cryosphere.net/4/261/2010/ http://www.the-cryosphere.net/4/261/2010/tc-4-261-2010.html http://www.the-cryosphere.net/4/261/2010/tc-4-261-2010.pdf 261 268 2010-07-23 An explanation for the dark region in the western melt zone of the Greenland ice sheet I. G. M. Wientjes J. Oerlemans Institute for Marine and Atmospheric Research (IMAU), Utrecht University, Utrecht, The Netherlands The western part of the Greenland ice sheet contains a region that is darker than the surrounding ice. This feature has been analysed with the help of MODIS images. The dark region appears every year during the summer season and can always be found at the same location, which makes meltwater unlikely as the only source for the low albedos. Spectral information indicates that the ice in this region contains more debris than the ice closer to the margin. ASTER images reveal a wavy pattern in the darker ice. 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