Simulated Internal Storage Buildup, Release, and Runoff from Greenland Ice Sheet at Kangerlussuaq, West Greenland

Abstract

This study focused on simulated glacier surface conditions (simulated Surface Melt and liquid Precipitation available for supra-, en-, sub-, and proglacial flow processes [after vertical percolation and potential storage within the snowpack] [henceforth SMP]), internal water storage and release, and runoff from the Kangerlussuaq drainage area of the Greenland Ice Sheet (GrIS), West Greenland, for the period 2006/2007 to 2007/2008. GrIS winter accumulation and summer ablation processes, including SMP, was simulated on both daily and hourly time steps. Using hourly meteorological driving data produced more realistic meteorological conditions instead of daily-averaged data, in relation to snow and melt threshold surface processes, and produced 9–17% higher annual cumulative SMP. The difference between simulated SMP and observed catchment runoff showed a decreasing lag time through the summer, and a drainage system storage buildup through approximately June and early July of up to 0.29 × 10⁹ m³, and a storage release through approximately late July and August of up to 0.25 × 10⁹ m³. The simulated total Kangerlussuaq SMP for 2006/2007 and 2007/2008, indicated a reduction of 30%. This reduction in SMP occurred simultaneously with the reduction in the overall pattern of satellite-derived GrIS surface melt from 2007 to 2008.

Acknowledgments

Very special thanks to the two anonymous reviewers for their insightful critique of this article. This work was supported by grants from the Climate Change Prediction Program and Scientific Discovery for Advanced Computing (SciDAC) program within the U.S. Department of Energy's Office of Science, by a Los Alamos National Laboratory (LANL) Director's Fellowship, and by a fellowship from the LANL Institute for Geophysics and Planetary Physics. LANL is operated under the auspices of the National Nuclear Security Administration of the U.S. Department of Energy under Contract No. DE-AC52-06NA25396. Thanks are given to the Institute of Geography and Geology, University of Copenhagen, for the use of observed Kangerlussuaq runoff data.