Articles | Volume 10, issue 5
The Cryosphere, 10, 2361–2377, 2016

Special issue: Mass balance of the Greenland Ice Sheet

The Cryosphere, 10, 2361–2377, 2016

Research article 13 Oct 2016

Research article | 13 Oct 2016

A daily, 1 km resolution data set of downscaled Greenland ice sheet surface mass balance (1958–2015)

Brice Noël1, Willem Jan van de Berg1, Horst Machguth2,3,4, Stef Lhermitte5, Ian Howat6, Xavier Fettweis7, and Michiel R. van den Broeke1 Brice Noël et al.
  • 1Institute for Marine and Atmospheric research Utrecht, Utrecht University, Utrecht, the Netherlands
  • 2Department of Geography, University of Zurich, Zurich, Switzerland
  • 3Department of Geosciences, University of Fribourg, Fribourg, Switzerland
  • 4Geological Survey of Denmark and Greenland GEUS, Copenhagen, Denmark
  • 5Department of Geoscience & Remote Sensing, Delft University of Technology, Delft, the Netherlands
  • 6Byrd Polar Research Center and School of Earth Sciences, Ohio State University, Columbus, USA
  • 7Department of Geography, University of Liège, Liège, Belgium

Abstract. This study presents a data set of daily, 1 km resolution Greenland ice sheet (GrIS) surface mass balance (SMB) covering the period 1958–2015. Applying corrections for elevation, bare ice albedo and accumulation bias, the high-resolution product is statistically downscaled from the native daily output of the polar regional climate model RACMO2.3 at 11 km. The data set includes all individual SMB components projected to a down-sampled version of the Greenland Ice Mapping Project (GIMP) digital elevation model and ice mask. The 1 km mask better resolves narrow ablation zones, valley glaciers, fjords and disconnected ice caps. Relative to the 11 km product, the more detailed representation of isolated glaciated areas leads to increased precipitation over the southeastern GrIS. In addition, the downscaled product shows a significant increase in runoff owing to better resolved low-lying marginal glaciated regions. The combined corrections for elevation and bare ice albedo markedly improve model agreement with a newly compiled data set of ablation measurements.

Short summary
We present a 1 km resolution data set (1958–2015) of daily Greenland ice sheet surface mass balance (SMB), statistically downscaled from the data of RACMO2.3 at 11 km using elevation dependence, precipitation and bare ice albedo corrections. The data set resolves Greenland narrow ablation zones and local outlet glaciers, and shows more realistic SMB patterns, owing to enhanced runoff at the ice sheet margins. An evaluation of the product against SMB measurements shows improved agreement.