Nansen Environmental and Remote Sensing Center, Bergen, NORWAY, Direction of Antarctic and Sub-Antarctic Programs, Universidad de Magallanes, Punta Arenas, CHILE, and Faculty of Engineering and Science, Western Norway University of Applied Sciences, Sogndal, Norway
Glen E. Liston
Cooperative Institute for Research in the Atmosphere, Colorado State University, Fort Collins, Colorado, USA
Andrew P. Beckerman
Department of Animal and Plant Sciences, University of Sheffield, UK
Jacob C. Yde
Faculty of Engineering and Science, Western Norway University of Applied Sciences, Sogndal, Norway
Abstract. Knowledge about variations in runoff from Greenland to adjacent fjords and seas is important for the hydrochemistry and ocean research communities to understand the link between terrestrial and marine Arctic environments. Here, we simulate the Greenland Ice Sheet (GrIS) surface mass balance (SMB), including refreezing and retention, and runoff together with catchment-scale runoff from the entire Greenland landmass (n = 3,272 simulated catchments) throughout the 35-year period 1979–2014. SnowModel/HydroFlow was applied at 3-h intervals to resolve the diurnal cycle and at 5-km horizontal grid increments using ERA-Interim (ERA-I) reanalysis atmospheric forcing. Simulated SMB was low compared to earlier studies, whereas the GrIS surface conditions and precipitation were similar. Variations in meteorological and surface ice and snow cover conditions influenced the seasonal variability in simulated catchment runoff; variations in the GrIS internal drainage system were assumed negligible and a time-invariant digital elevation model was applied. Approximately 80 % of all catchments showed increasing runoff trends over the 35 years, with on average relatively high and low catchment-scale runoff from the SW and N parts of Greenland, respectively. Outputs from an Empirical Orthogonal Function (EOF) analysis were combined with cross-correlations indicating a direct link (zero lag time) between modeled catchment-scale runoff and variations in the large-scale atmospheric circulation indices North Atlantic Oscillation (NAO) and Atlantic Multidecadal Oscillation (AMO). This suggests that natural variabilities in AMO and NAO constitute major controls on catchment-scale runoff variations in Greenland.
How to cite. Mernild, S. H., Liston, G. E., Beckerman, A. P., and Yde, J. C.: Reconstruction of the Greenland Ice Sheet surface
mass balance and the spatiotemporal distribution of
freshwater runoff from Greenland to surrounding seas, The Cryosphere Discuss. [preprint], https://doi.org/10.5194/tc-2017-234, 2017.
Received: 14 Oct 2017 – Discussion started: 24 Oct 2017
This study is about simulating the Greenland Ice Sheet surface mass balance, and the related snow refreezing conditions and the spatio-temporal Greenland distribution of freshwater runoff to surrounding seas. Runoff has increased since 1979, and can be used as input for numerical ocean models linking the terrestrial runoff to changes in the near-coastal seas. This will provide us with an increasing understanding how Greenland is linked to the surrounding seas. SnowModel and ERA-I were used here.
This study is about simulating the Greenland Ice Sheet surface mass balance, and the related...