[en] Mass loss from the two major ice sheets and their contribution to global sea level rise is accelerating. In Antarctica, mass loss is dominated by increased flow velocities of outlet glaciers, following the thinning or disintegration of coastal ice shelves into which they flow. In contrast, ∼55% of post‒1992 Greenland ice sheet (GrIS) mass loss is accounted for by surface processes, notably increased meltwater runoff. A subtle process in the surface mass balance of the GrIS is the retention and refreezing of meltwater, currently preventing ∼40% of the meltwater to reach the ocean. Here we force a high‒resolution atmosphere/snow model with a mid‒range warming scenario (RCP4.5, 1970–2100), to show that rapid loss of firn pore space, by >50% at the end of the 21st century, quickly reduces this refreezing buffer. As a result, GrIS surface mass loss accelerates throughout the 21st century and its contribution to global sea level rise increases to 1.7 ±0.5 mm yr−1, more than four times the current value.
Disciplines :
Earth sciences & physical geography
Author, co-author :
van Angelen, J.
Lenaerts, J.
van den Broeke, M.
Fettweis, Xavier ; Université de Liège - ULiège > Département de géographie > Topoclimatologie
van Meijgaard, E.
Language :
English
Title :
Rapid loss of firn pore space accelerates 21st century Greenland mass loss
Publication date :
23 May 2013
Journal title :
Geophysical Research Letters
ISSN :
0094-8276
eISSN :
1944-8007
Publisher :
American Geophysical Union, Washington, United States - District of Columbia
Bellouin, N., et al. (2011), The HadGEM2 family of Met Office Unified Model climate configurations, Geosci. Model Dev., 4, 723-757, doi: 10.5194/gmd-4-723-2011.
Ettema, J., M. R. Van den Broeke, E. Van Meijgaard, W. J. Van de Berg, J. L. Bamber, J. E. Box, and, R. C. Bales, (2009), Higher surface mass balance of the Greenland ice sheet revealed by high-resolution climate modeling, Geophys. Res. Lett., 36, L12,501, doi: 10.1029/2009GL038110.
Ettema, J., M. R. Van den Broeke, E. Van Meijgaard, and, W. J. Van de Berg, (2010), Climate of the Greenland ice sheet using a high-resolution climate model, Part 1: Evaluation, The Cryosphere, 4, 511-527, doi: 10.5194/tc-4-511-2010.
Fettweis, X., M. Tedesco, M. R. Van den Broeke, and, J. Ettema, (2011), Melting trends over the Greenland ice sheet (1958-2009) from spaceborne microwave data and regional climate models, The Cryosphere, 5, 359-375, doi: 10.5194/tc-5-359-2011.
Fettweis, X., B. Franco, M. Tedesco, J. H. V. Angelen, J. T. M. Lenaerts, M. R. V. D. Broeke, and, H. Gallée, (2012), Estimating Greenland ice sheet surface mass balance contribution to future sea level rise using the regional atmospheric climate model MAR, The Cryosphere Discuss., 6, 3101-3147, doi: 10.5194/tcd-6-3101-2012.
Goelzer, H., P. Huybrechts, S. Raper, M. Loutre, H. Goosse, and, T. Fichefet, (2012), Millennial total sea-level commitments projected with the earth system model of intermediate complexity LOVECLIM, Environ. Res. Lett., 7, 045,401, doi: 10.1088/1748-9326/7/4/045401.
Hanna, E., P. Huybrechts, and, K. Steffen, (2008), Increased runoff from melt from the Greenland ice sheet: A response to global warming, J. Climate, 21, 331-341, doi: 10.1175/2007JCLI1964.1.
Harper, J., N. Humphrey, W. T. Pfeffer, J. Brown, and, X. Fettweis, (2012), Greenland ice-sheet contribution to sea-level rise buffered by meltwater storage in firn, Nature, 491, 240-243, doi: 10.1038/nature11566.
Jones, C. D., et al. (2011), The HadGEM2-ES implementation of CMIP5 centennial simulations, Geosci. Model Dev., 4, 543-570, doi: 10.5194/gmd-4-543-2011.
Kuipers Munneke, P., M. R. Van den Broeke, J. T. M. Lenaerts, M. G. Flanner, A. S. Gardner, and, W. J. Van de Berg, (2011), A new albedo parameterization for use in climate models over the Antarctic ice sheet, J. Geophys. Res., 116, D05,114, doi: 10.1029/2010JD015113.
Lenaerts, J. T. M., J. H. V. Angelen, M. R. V. den Broeke, A. S. Gardner, B. Wouters, and, E. V. Meijgaard, (2013), Irreversible mass loss of Canadian Arctic archipelago glaciers, Geophys. Res. Lett., 40, 1-5, doi: 10.1002/grl.50214.
Moss, R. H., et al. (2010), The next generation of scenarios for climate change research and assessment, Nature, 463, 747-756, doi: 10.1038/nature08823.
Pritchard, H. D., S. R. M. Ligtenberg, H. A. Fricker, D. G. Vaughan, M. R. Van den Broeke, and, L. Padman, (2012), Antarctic ice-sheet loss driven by basal melting of ice shelves, Nature, 484, 502-505, doi: 10.1038/nature10968.
Reijmer, C. H., M. R. V. D. Broeke, X. Fettweis, J. Ettema, and, L. B. Stap, (2012), Refreezing on the Greenland ice sheet: A comparison of parameterizations, The Cryosphere, 6, 743-762, doi: 10.5194/tc-6-743-2012.
Rignot, E., J. L. Bamber, M. Van den Broeke, C. Davis, Y. Li, W. Van de Berg, and, E. Van Meijgaard, (2008), Recent Antarctic ice mass loss from radar interferometry and regional climate modelling, Nat. Geosci., 1, 106-110, doi: 10.1038/ngeo102.
Rignot, E., I. Velicogna, M. R. Van Den Broeke, A. Monaghan, and, J. T. M. Lenaerts, (2011), Acceleration of the contribution of the Greenland and Antarctic ice sheets to sea level rise, Geophys. Res. Lett., 38, L05,503, doi: 10.1029/2011GL046583.
Shepherd, A., et al. (2012), A reconciled estimate of ice sheet mass balance, Science, 338, 1183-1189, doi: 10.1126/science.1228102.
Taylor, K. E., R. J. Stouffer, and, G. A. Meehl, (2007), A summary of the CMIP5 experiment design, World, 4, 1-33.
Van Angelen, J. H., J. T. M. Lenaerts, S. Lhermitte, X. Fettweis, P. Kuipers Munneke, M. R. Van den Broeke, E. Van Meijgaard, and, C. J. P. P. Smeets, (2012), Sensitivity of Greenland ice sheet surface mass balance to surface albedo parameterization: A study with a regional climate model, The Cryosphere, 6, 1175-1186, doi: 10.5194/tc-6-1175-2012.
Van den Broeke, M. R., J. L. Bamber, J. Ettema, E. Rignot, E. Schrama, W. J. Van de Berg, E. Van Meijgaard, I. Velicogna, and, B. Wouters, (2009), Partitioning recent Greenland mass loss, Science, 326, 984, doi: 10.1126/science.1178176.
Van den Broeke, M. R., J. L. Bamber, J. T. M. Lenaerts, and, E. Rignot, (2011), Ice sheets and sea level: Thinking outside the box, Surv. Geophys., 27, pp. 1-11, doi: 10.1007/s10712-011-9137-z.
Van Meijgaard, E., L. H. van Ulft, W. J. van de Berg, F. C. Bosveld, B. van den Hurk, G. Lenderink, and, A. P. Siebesma, (2008), The KNMI regional atmospheric climate model RACMO version 2.1, Tech. Rep. 302.
Zwally, H. J., et al. (2011), Greenland ice sheet mass balance: Distribution of increased mass loss with climate warming; 2003-07 versus 1992-2002, J. Glaciol., 57, 88-102, doi: 10.3189/002214311795306682.