Greenland iceberg melt variability from high-resolution satellite observations

• Published in: The Cryosphere
• Main Authors: E. M. Enderlin, C. J. Carrigan, W. H. Kochtitzky, A. Cuadros, T. Moon, G. S. Hamilton
• Format: Article in Journal/Newspaper
• Language: English
• Published: Copernicus Publications 2018
• Subjects: Environmental sciences; GE1-350; Geology; QE1-996.5; Greenland; Jakobshavn Isbræ; Ice Sheet; Jakobshavn; Jakobshavn isbræ; The Cryosphere
• Online Access: https://doi.org/10.5194/tc-12-565-2018; https://doaj.org/article/3bf582c5a15e4b2ebc86716c22e30891

Iceberg discharge from the Greenland Ice Sheet accounts for up to half of the freshwater flux to surrounding fjords and ocean basins, yet the spatial distribution of iceberg meltwater fluxes is poorly understood. One of the primary limitations for mapping iceberg meltwater fluxes, and changes over time, is the dearth of iceberg submarine melt rate estimates. Here we use a remote sensing approach to estimate submarine melt rates during 2011–2016 for 637 icebergs discharged from seven marine-terminating glaciers fringing the Greenland Ice Sheet. We find that spatial variations in iceberg melt rates generally follow expected patterns based on hydrographic observations, including a decrease in melt rate with latitude and an increase in melt rate with iceberg draft. However, we find no longitudinal variations in melt rates within individual fjords. We do not resolve coherent seasonal to interannual patterns in melt rates across all study sites, though we attribute a 4-fold melt rate increase from March to April 2011 near Jakobshavn Isbræ to fjord circulation changes induced by the seasonal onset of iceberg calving. Overall, our results suggest that remotely sensed iceberg melt rates can be used to characterize spatial and temporal variations in oceanic forcing near often inaccessible marine-terminating glaciers.