文章基本信息

标题：Automated remote sensing of sediment plumes for identification of runoff from the Greenland ice sheet
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作者：Andrew J. Tedstone ; Neil S. Arnold
期刊名称：Journal of Glaciology
印刷版ISSN：0022-1430
电子版ISSN：1727-5652
出版年度：2012
卷号：58
期号：210
页码：699-712
DOI：10.3189/2012JoG11J204
出版社：Cambridge University Press
摘要：The viability of employing sediment plumes emanating from outlets along the western margin of the Greenland ice sheet as indicators of runoff is assessed. An automated sediment plume quantification system based on daily 250 m Moderate Resolution Imaging Spectroradiometer (MODIS) band 1 reflectance imagery is developed. Coherent plumes are identified using spectral thresholds and polygon tracing. Validation employs imagery quality-control procedures and manual verification of plume areas. Outlets at land-terminating margins with wide and straight fjord geometries deliver the most accurate and consistent results. Plume area observations are also possible at marine-terminating margins with relatively static fronts and low proximal sea-ice concentrations. Variability in plume area is examined with reference to Special Satellite Microwave Imager (SSM/I)-derived daily melt extent at the hydrologic catchment scale. At annual timescales, plume areas tend to co-vary with surface melt extent, indicating that more mass is lost by runoff during years of extensive melting. Some synchronicity in plume areas from different catchments is apparent. At seasonal and daily timescales, plumes from individual outlets primarily relate to catchment-specific melting.