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
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