Multi-temporal, multi-sensor investigations of supra-glacial lakes on the Greenland Ice Sheet
2011 (English)In: Proceedings of ESA Living Planet Symposium: 28 June - 2 July 2010, Bergen, Norway(DVD) / [ed] H. Lacoste-Francis, Noordwijk: ESA (European Space Agency) , 2011Conference paper (Other academic)
The stability of the ice sheets is affected by the ongoing climate change through changes in the meltwater budget and effects on ice sheet dynamics. Surface lakes on the Greenland Ice Sheet have attracted much attention, but assessing their number and size as well as the variability over time of these parameters is not straight-forward. We present a satellite image-based survey of the total lake area and number of supra-glacial lakes in a specific region on the western margin of the Greenland Ice Sheet. Optical images from two different sensors (Moderate Resolution Imaging Spectroradiometer (MODIS) and Landsat) and images from three different synthetic aperture radar (SAR) satellites (Radarsat, ERS and Envisat) from 2001, 2006 and 2007, were used in order to manually digitize the extent of supra-glacial lakes. The image spatial resolution ranges from high (Radarsat, ERS and Landsat) to moderate (Envisat and MODIS) where high resolution corresponds to 6.25 to 25 m, and a moderate resolution corresponds to 50 to 250 m. SAR imagery was tested as a supplement to the more commonly used optical data to fill gaps in the time series caused by frequent cloud cover. In total 709 individual lakes were studied. High resolution images were shown to be preferable in the beginning of the melt season, due to the smaller size of the lakes. In the middle of the melt season the resolution was of limited importance. Our work suggests that the use of a combination of active radar and optical images enables successful lake monitoring with high temporal and spatial resolution in both cloudy and clear weather conditions.
Place, publisher, year, edition, pages
Noordwijk: ESA (European Space Agency) , 2011.
Greenland, Remote Sensing, SAR, supra-glacial lakes
Research subject Physical Geography
IdentifiersURN: urn:nbn:se:su:diva-74504ISBN: 978-92-9221-250-6OAI: oai:DiVA.org:su-74504DiVA: diva2:510104
ESA Living Planet Symposium: 28 June - 2 July 2010, Bergen, Norway