Greenland Iceberg Melt Variability from High-Resolution Satellite Observations | CU Experts

Abstract. 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 large 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 general decrease in melt rate with latitude and an increase in melt rate with iceberg draft. We do not resolve coherent temporal variations in iceberg melt rates across all study sites, though we attribute a four-fold increase in iceberg melt rates from March to April 2011 near Jakobshavn Isbræ's terminus to rapid 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 marine-terminating glaciers, including regions largely inaccessible for in situ study.;

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