An explanation for the dark region in the western melt zone of the Greenland ice sheet

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 unlikel...

Full description

Bibliographic Details
Published in:The Cryosphere
Main Authors: I. G. M. Wientjes, J. Oerlemans
Format: Article in Journal/Newspaper
Language:English
Published: Copernicus Publications 2010
Subjects:
Online Access:https://doi.org/10.5194/tc-4-261-2010
https://doaj.org/article/36f07ec170d64845a3b00f0cac36ccd8
Description
Summary: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. Based on these findings we conclude that ice, containing dust from older periods, is presently outcropping near the margin, leading to albedos lower than observed for the remaining ablation area. Therefore it can be concluded that the accumulation of meltwater is a result rather than a cause of the darkening.