altimetry; CryoSat-2; GRACE; Greenland Ice Sheet; mass balance; Cryosat; Mass balance; Geophysics; Earth and Planetary Sciences (all); General Earth and Planetary Sciences
Abstract :
[en] We map recent Greenland Ice Sheet elevation change at high spatial (5 km) and temporal (monthly) resolution using CryoSat-2 altimetry. After correcting for the impact of changing snowpack properties associated with unprecedented surface melting in 2012, we find good agreement (3 cm/yr bias) with airborne measurements. With the aid of regional climate and firn modeling, we compute high spatial and temporal resolution records of Greenland mass evolution, which correlate (R = 0.96) with monthly satellite gravimetry and reveal glacier dynamic imbalance. During 2011–2014, Greenland mass loss averaged 269 ± 51 Gt/yr. Atmospherically driven losses were widespread, with surface melt variability driving large fluctuations in the annual mass deficit. Terminus regions of five dynamically thinning glaciers, which constitute less than 1% of Greenland's area, contributed more than 12% of the net ice loss. This high-resolution record demonstrates that mass deficits extending over small spatial and temporal scales have made a relatively large contribution to recent ice sheet imbalance.
Disciplines :
Earth sciences & physical geography
Author, co-author :
McMillan, Malcolm; Centre for Polar Observation and Modelling, University of Leeds, Leeds, United Kingdom
Leeson, Amber; Data Science Institute and Lancaster Environment Center, University of Lancaster, Lancaster, United Kingdom
Shepherd, Andrew; Centre for Polar Observation and Modelling, University of Leeds, Leeds, United Kingdom
Briggs, Kate; Centre for Polar Observation and Modelling, University of Leeds, Leeds, United Kingdom
Armitage, Thomas W. K.; Centre for Polar Observation and Modelling, University College London, London, United Kingdom
Hogg, Anna; Centre for Polar Observation and Modelling, University of Leeds, Leeds, United Kingdom
Kuipers Munneke, Peter; Institute for Marine and Atmospheric Research, Utrecht University, Utrecht, Netherlands
van den Broeke, Michiel; Institute for Marine and Atmospheric Research, Utrecht University, Utrecht, Netherlands
Noël, Brice ; Université de Liège - ULiège > Département de géographie > Climatologie et Topoclimatologie ; Institute for Marine and Atmospheric Research, Utrecht University, Utrecht, Netherlands
van de Berg, Willem Jan; Institute for Marine and Atmospheric Research, Utrecht University, Utrecht, Netherlands
Ligtenberg, Stefan; Institute for Marine and Atmospheric Research, Utrecht University, Utrecht, Netherlands
Horwath, Martin; Institut für Planetare Geoädsie, Technische Universität Dresden, Dresden, Germany
Groh, Andreas; Institut für Planetare Geoädsie, Technische Universität Dresden, Dresden, Germany
Muir, Alan; Centre for Polar Observation and Modelling, University College London, London, United Kingdom
Gilbert, Lin; Centre for Polar Observation and Modelling, University College London, London, United Kingdom
A, G., J. Wahr, and S. Zhong (2013), Computations of the viscoelastic response of a 3-D compressible Earth to surface loading: An application to glacial isostatic adjustment in Antarctica and Canada, Geophys. J. Int., 192(2), 557–572, doi:10.1093/gji/ggs030.
Arthern, R. J., D. J. Wingham, and A. L. Ridout (2001), Controls on ERS altimeter measurements over ice sheets: Footprint-scale topography, backscatter fluctuations, and the dependence of microwave penetration depth on satellite orientation, J. Geophys. Res., 106(D24), 33,471–33,484, doi:10.1029/2001JD000498.
Bolch, T., L. Sandberg Sørensen, S. B. Simonsen, N. Mölg, H. MacHguth, P. Rastner, and F. Paul (2013), Mass loss of Greenland's glaciers and ice caps 2003–2008 revealed from ICESat laser altimetry data, Geophys. Res. Lett., 40, 875–881, doi:10.1002/grl.50270.
Csatho, B. M., A. F. Schenk, C. J. van der Veen, G. Babonis, K. Duncan, S. Rezvanbehbahani, M. R. van den Broeke, S. B. Simonsen, S. Nagarajan, and J. H. van Angelen (2014), Laser altimetry reveals complex pattern of Greenland Ice Sheet dynamics, Proc. Natl. Acad. Sci. U.S.A., 111(52), 18,478–18,483, doi:10.1073/pnas.1411680112.
Davis, C. H., Y. H. Li, J. R. McConnell, M. M. Frey, and E. Hanna (2005), Snowfall-driven growth in East Antarctic Ice Sheet mitigates recent sea-level rise, Science, 308(5730), 1898–1901, doi:10.1126/science.1110662.
Enderlin, E., I. Howat, S. Jeong, M. Noh, J. van Angelen, and M. van den Broeke (2014), An improved mass budget for the Greenland Ice Sheet, Geophys. Res. Lett., 41, 866–872, doi:10.1002/2013GL059010.
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, L12501, doi:10.1029/2009GL038110.
Fettweis, X., E. Hanna, C. Lang, A. Belleflamme, M. Erpicum, and H. Gall (2013a), Brief communication “Important role of the mid-tropospheric atmospheric circulation in the recent surface melt increase over the Greenland Ice Sheet”, Cryosphere, 7, 241–248, doi:10.5194/tc-7-241-2013.
Fettweis, X., B. Franco, M. Tedesco, J. H. Van Angelen, J. T. M. Lenaerts, M. R. Van Den Broeke, and H. Gallee (2013b), Estimating the Greenland Ice Sheet surface mass balance contribution to future sea level rise using the regional atmospheric climate model MAR, Cryosphere, 7, 469–489, doi:10.5194/tc-7-469-2013.
Flament, T., and F. Rémy (2012), Dynamic thinning of Antarctic glaciers from along-track repeat radar altimetry, J. Glaciol., 58(211), 830–840, doi:10.3189/2012JoG11J118.
Gray, L., D. Burgess, L. Copland, M. N. Demuth, T. Dunse, K. Langley, and T. V. Schuler (2015), CryoSat-2 delivers monthly and inter-annual surface elevation change for Arctic ice caps, Cryosphere, 9, 1895–1913, doi:10.5194/tc-9-1895-2015.
Hanna, E., P. Huybrechts, K. Steffen, J. Cappelen, R. Huff, C. Shuman, T. Irvine-Fynn, S. Wise, and M. Griffiths (2008), Increased runoff from melt from the Greenland Ice Sheet: A response to global warming, J. Clim., 21(2), 331–341, doi:10.1175/2007JCLI1964.1.
Hanna, E., S. H. Mernild, J. Cappelen, and K. Steffen (2012), Recent warming in Greenland in a climatic context: I. Evaluation of surface air temperature records, Environ. Res. Lett., 7, doi:10.1088/1748-9326/7/4/045404.
Hanna, E., X. Fettweis, S. H. Mernild, J. Cappelen, M. H. Ribergaard, C. A. Shuman, K. Steffen, L. Wood, and T. L. Mote (2014), Atmospheric and oceanic climate forcing of the exceptional Greenland Ice Sheet surface melt in summer 2012, Int. J. Climatol., 34(4), 1022–1037, doi:10.1002/joc.3743.
Haran, T., J. Bohlander, T. Scambos, T. Painter, and M. Fahnestock (2013), MODIS Mosaic of Greenland (MOG) Image Map, Version 1, NSIDC Natl. Snow Ice Data Cent, Boulder, Colo.
Helm, V., A. Humbert, and H. Miller (2014), Elevation and elevation change of Greenland and Antarctica derived from CryoSat-2, Cryosphere, 8(4), 1539–1559, doi:10.5194/tc-8-1539-2014.
Horwath, M., and R. Dietrich (2009), Signal and error in mass change inferences from GRACE: the case of Antarctica, Geophys. J. Int., 177, 849–864, doi:10.1111/j.1365-246X.2009.04139.x.
Joughin, I., B. E. Smith, I. M. Howat, T. Scambos, and T. Moon (2010), Greenland flow variability from ice-sheet-wide velocity mapping, J. Glaciol., 56(197), 415–430.
Khan, S. A., A. Aschwanden, A. A. Bjørk, J. Wahr, K. K. Kjeldsen, and K. H. Kjaer (2015), Greenland Ice Sheet mass balance: A review, Rep. Prog. Phys., 78(4, 046801), doi:10.1088/0034-4885/78/4/046801.
Krabill, W. (2014), IceBridge ATM L2 Icessn Elevation, Slope, and Roughness, Version 2, NASA DAAC Natl. Snow Ice Data Center, Boulder, Colo.
Kuipers Munneke, P., et al. (2015), Elevation change of the Greenland Ice Sheet due to surface mass balance and firn processes, 1960–2013, Cryosphere Discuss., 9(3), 3541–3580, doi:10.5194/tcd-9-3541-2015.
Li, J., and H. J. Zwally (2011), Modeling of firn compaction for estimating ice-sheet mass change from observed ice-sheet elevation change, Ann. Glaciol., 52(59), 1–7, doi:10.3189/172756411799096321.
Ligtenberg, S. R. M., M. M. Helsen, and M. R. Van Den Broeke (2011), An improved semi-empirical model for the densification of Antarctic firn, Cryosphere, 5(4), 809–819, doi:10.5194/tc-5-809-2011.
McMillan, M., A. Shepherd, A. Sundal, K. Briggs, A. Muir, A. Ridout, A. Hogg, and D. Wingham (2014a), Increased ice losses from Antarctica detected by CryoSat-2, Geophys. Res. Lett., 41, 1–7, doi:10.1002/2014GL060111.
McMillan, M., et al. (2014b), Rapid dynamic activation of a marine-based Arctic ice cap, Geophys. Res. Lett., 41, 8902–8909, doi:10.1002/2014GL062255.
Mohr, J. J., N. Reeh, and S. N. Madsen (1998), Three-dimensional glacial flow and surface elevation measured with radar interferometry, Nature, 391(6664), 273–276, doi:10.1038/34635.
Moon, T., I. Joughin, B. E. Smith, and I. M. Howat (2012), 21st-century evolution of Greenland outlet glacier velocities, Science, 336(576), doi:10.1126/science.1219985.
Nghiem, S. V., D. K. Hall, T. L. Mote, M. Tedesco, M. R. Albert, K. Keegan, C. A. Shuman, N. E. DiGirolamo, and G. Neumann (2012), The extreme melt across the Greenland Ice Sheet in 2012, Geophys. Res. Lett., 39, L20502, doi:10.1029/2012GL053611.
Nilsson, J., et al. (2015), Greenland 2012 melt event effects on CryoSat-2 radar altimetry, Geophys. Res. Lett., 42, 3919–3926, doi:10.1002/2015GL063296.
Noël, B., W. J. van de Berg, E. van Meijgaard, P. Kuipers Munneke, R. S. W. van de Wal, and M. R. van den Broeke (2015), Evaluation of the updated regional climate model RACMO2.3: Summer snowfall impact on the Greenland Ice Sheet, Cryosphere, 9(5), 1831–1844, doi:10.5194/tc-9-1831-2015.
Peltier, W. R. (2004), Global glacial isostasy and the surface of the Ice-Age Earth: The ICE-5G (VM2) model and GRACE, Annu. Rev. Earth Planet. Sci., 32(1), 111–149, doi:10.1146/annurev.earth.32.082503.144359.
Rignot, E., I. Velicogna, M. R. van den Broeke, A. Monaghan, and J. Lenaerts (2011), Acceleration of the contribution of the Greenland and Antarctic Ice Sheets to sea level rise, Geophys. Res. Lett., 38, L05503, doi:10.1029/2011GL046583.
Schrama, E. J. O., B. Wouters, and R. Rietbroek (2014), A mascon approach to assess ice sheet and glacier mass balances and their uncertainties from GRACE data, J. Geophys. Res. Solid Earth, 119, 6048–6066, doi:10.1002/2013JB010923.
Scott, J. B. T., P. Nienow, D. Mair, V. Parry, E. Morris, and D. J. Wingham (2006), Importance of seasonal and annual layers in controlling backscatter to radar altimeters across the percolation zone of an ice sheet, Geophys. Res. Lett., 33, L24502, doi:10.1029/2006GL027974.
Shepherd, A., and D. Wingham (2007), Recent sea-level contributions of the Antarctic and Greenland Ice Sheets, Science, 315(5818), 1529–1532.
Shepherd, A., et al. (2012), A reconciled estimate of ice-sheet mass balance, Science, 338(6111), 1183–1189, doi:10.1126/science.1228102.
Smith, B., H. A. Fricker, I. Joughin, and S. Tulaczyk (2009), An inventory of active subglacial lakes in Antarctica detected by ICESat (2003–2008), J. Glaciol., 55(192), 573–595.
Sørensen, L. S., S. B. Simonsen, K. Nielsen, P. Lucas-Picher, G. Spada, G. Adalgeirsdottir, R. Forsberg, and C. S. Hvidberg (2011), Mass balance of the Greenland Ice Sheet (2003–2008) from ICESat data—The impact of interpolation, sampling and firn density, Cryosphere, 5, 173–186, doi:10.5194/tc-5-173-2011.
Swenson, S., and J. Wahr (2002), Methods for inferring regional surface-mass anomalies from Gravity Recovery and Climate Experiment (GRACE) measurements of time-variable gravity, J. Geophys. Res., 107(B9), 2193, doi:10.1029/2001JB000576.
Tedesco, M., X. Fettweis, T. Mote, J. Wahr, P. Alexander, J. E. Box, and B. Wouters (2013), Evidence and analysis of 2012 Greenland records from spaceborne observations, a regional climate model and reanalysis data, Cryosphere, 7(2), 615–630, doi:10.5194/tc-7-615-2013.
Tedstone, A. J., P. W. Nienow, N. Gourmelen, A. Dehecq, D. Goldberg, and E. Hanna (2015), Decadal slowdown of a land-terminating sector of the Greenland Ice Sheet despite warming, Nature, 526(7575), 692–695, doi:10.1038/nature15722.
Thomas, R., E. Frederick, W. Krabill, S. Manizade, and C. Martin (2006), Progressive increase in ice loss from Greenland, Geophys. Res. Lett., 33, L10503, doi:10.1029/2006GL026075.
van de Wal, R. S. W., W. Boot, M. R. van den Broeke, C. J. P. P. Smeets, C. H. Reijmer, J. J. A. Donker, and J. Oerlemans (2008), Large and rapid melt-induced velocity changes in the ablation zone of the Greenland Ice Sheet, Science, 321(5885), 111–113, doi:10.1126/science.1158540.
van den Broeke, M., J. 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(5955), 984–986, doi:10.1126/science.1178176.
Vaughan, D. G., et al. (2013), Observations: Cryosphere, in Climate Change 2013: Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change, edited by T. F. Stocker et al., Cambridge Univ. Press, Cambridge, U. K.
Velicogna, I., and J. Wahr (2013), Time-variable gravity observations of ice sheet mass balance: Precision and limitations of the GRACE satellite data, Geophys. Res. Lett., 40, 3055–3063, doi:10.1002/grl.50527.
Wingham, D. J., A. Shepherd, A. Muir, and G. J. Marshall (2006), Mass balance of the Antarctic Ice Sheet, Philos. Trans. R. Soc. A Math. Phys. Eng. Sci., 364(1844), 1627–1635, doi:10.1098/rsta.2006.1792.
Zwally, H. J., M. B. Giovinetto, J. Li, H. G. Cornejo, M. A. Beckley, A. C. Brenner, J. L. Saba, and D. Yi (2005), Mass changes of the Greenland and Antarctic Ice Sheets and shelves and contributions to sea-level rise: 1992–2002, J. Glaciol., 51(175), 509–527.
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(201), 88–102, doi:10.3189/002214311795306682.