van As, Dirk9; Langer Andersen, Morten9; Petersen, Dorthe3; Fettweis, Xavier10; van Angelen, Jan H.5; Lenaerts, Jan T. M.5; van den Broeke, Michiel R.5; M. Lea, James6; Bøggild, Carl Egede7; Ahlstrøm, Andreas P.9; Steffen, Konrad11
1 Department of Civil Engineering, Technical University of Denmark2 Geological Survey of Denmark and Greenland3 ASIAQ Greenland Survey4 University of Liege5 Utrecht University6 University of Aberdeen7 Section for Arctic Technology, Department of Civil Engineering, Technical University of Denmark8 Swiss Federal Institute for Forest, Snow and Landscape Research (WSL)9 Geological Survey of Denmark and Greenland10 University of Liege11 Swiss Federal Institute for Forest, Snow and Landscape Research (WSL)
We assess the runoff and surface mass balance (SMB) of the Greenland ice sheet in the Nuuk region (southwest) using output of two regional climate models (RCMs) evaluated by observations. The region encompasses six glaciers that drain into Godthåbsfjord. RCM data (1960-2012) are resampled to a high spatial resolution to include the narrow (relative to the native grid spacing) glacier trunks in the ice mask. Comparing RCM gridded results with automaticweather station (AWS) point measurements reveals that locally models can underestimate ablation andoverestimate accumulation by up to tens of per cent. However, comparison with lake discharge indicates that modelled regional runoff totals are more accurate. Model results show that melt and runoff in the Nuuk region have doubled over the past wo decades. Regional SMB attained negative values in recent high-melt years. Taking into account frontal ablation of the marine-terminating glaciers, the region lost 10-20km3w.e. a-1 in 2010-12. If 2010 melting prevails during the remainder of this century, a low-end estimate of sea-level rise of 5mm is expected by 2100 from this relatively small section (2.6%) of the ice sheet alone.
Journal of Glaciology, 2014, Vol 60, Issue 220, p. 314-322