Greenland ice sheet surface mass balance: evaluating simulations and making projections with regional climate models 1Met Office Hadley Centre, FitzRoy Road, Exeter, EX1 3PB, United Kingdom
09 Nov 2012
2Danish Meteorological Institute, Lyngbyvej 100, DK-2100 Copenhagen, Denmark
3School of Geographical Sciences, University of Bristol, University Road, Bristol, BS8 1SS, United Kingdom
4Department of Geography, University of Liège, 2, Allée du 6 Août, Bat. B11, 4000 Liège, Belgium
5Department of Meteorology, University of Reading, Earley Gate, PO Box 243, Reading, RG6 6BB, United Kingdom
6Institute for Marine and Atmospheric research Utrecht, Utrecht University, P.O. Box 80005, 3508 TA Utrecht, The Netherlands
*currently at: Institute of Earth Sciences, Sturlugata 7, Askja, 101 Reykjavík, Iceland
**currently at: Rossby Centre, SMHI, Folkborgsvägen 1, S-601 76 Norrköping, Sweden
Received: 11 May 2012 – Published in The Cryosphere Discuss.: 13 Jun 2012 Abstract. Four high-resolution regional climate models (RCMs) have been set up for
the area of Greenland,
with the aim of providing future projections of Greenland ice sheet surface mass balance (SMB),
and its contribution to sea level rise, with
greater accuracy than is possible from coarser-resolution general circulation models (GCMs).
This is the first time an intercomparison has been carried out
of RCM results for Greenland climate and SMB.
Output from RCM simulations for the recent past with the four RCMs is evaluated against available
observations. The evaluation highlights the importance of
using a detailed snow physics scheme, especially regarding
the representations of albedo and meltwater refreezing.
Simulations with three of the RCMs for the 21st
century using SRES scenario A1B from two GCMs produce trends of between −5.5 and −1.1 Gt yr−2
in SMB (equivalent to +0.015 and +0.003 mm sea level equivalent yr−2),
with trends of smaller magnitude for scenario E1, in which emissions are mitigated. Results from
one of the RCMs whose present-day simulation is most realistic
indicate that an annual mean near-surface air temperature increase
over Greenland of ~ 2°C would be required for the mass loss to increase such that it exceeds
accumulation, thereby causing the SMB to become negative,
which has been suggested as a threshold beyond which the ice sheet
would eventually be eliminated.
Revised: 17 Sep 2012 – Accepted: 26 Sep 2012 – Published: 09 Nov 2012
Citation: Rae, J. G. L., Aðalgeirsdóttir, G., Edwards, T. L., Fettweis, X., Gregory, J. M., Hewitt, H. T., Lowe, J. A., Lucas-Picher,
P., Mottram, R. H., Payne, A. J., Ridley, J. K., Shannon, S. R., van de Berg, W. J., van de Wal, R. S. W., and van den Broeke, M. R.: Greenland ice sheet surface mass balance: evaluating simulations and making projections with regional climate models, The Cryosphere, 6, 1275-1294, doi:10.5194/tc-6-1275-2012, 2012.