Chemistry (all); Biochemistry, Genetics and Molecular Biology (all); Multidisciplinary; Physics and Astronomy (all); General Physics and Astronomy; General Biochemistry, Genetics and Molecular Biology; General Chemistry
Abstract :
[en] Runoff from the Greenland Ice Sheet has increased over recent decades affecting global sea level, regional ocean circulation, and coastal marine ecosystems, and it now accounts for most of the contemporary mass imbalance. Estimates of runoff are typically derived from regional climate models because satellite records have been limited to assessments of melting extent. Here, we use CryoSat-2 satellite altimetry to produce direct measurements of Greenland's runoff variability, based on seasonal changes in the ice sheet's surface elevation. Between 2011 and 2020, Greenland's ablation zone thinned on average by 1.4 ± 0.4 m each summer and thickened by 0.9 ± 0.4 m each winter. By adjusting for the steady-state divergence of ice, we estimate that runoff was 357 ± 58 Gt/yr on average - in close agreement with regional climate model simulations (root mean square difference of 47 to 60 Gt/yr). As well as being 21 % higher between 2011 and 2020 than over the preceding three decades, runoff is now also 60 % more variable from year-to-year as a consequence of large-scale fluctuations in atmospheric circulation. Because this variability is not captured in global climate model simulations, our satellite record of runoff should help to refine them and improve confidence in their projections.
Research center :
SPHERES - ULiège
Disciplines :
Earth sciences & physical geography
Author, co-author :
Slater, Thomas ; Centre for Polar Observation and Modelling, School of Earth and Environment, University of Leeds, Leeds, UK. t.slater1@leeds.ac.uk
Shepherd, Andrew; Centre for Polar Observation and Modelling, School of Earth and Environment, University of Leeds, Leeds, UK
McMillan, Malcolm; Lancaster Environment Centre, Lancaster University, Lancaster, UK
Leeson, Amber ; Lancaster Environment Centre, Lancaster University, Lancaster, UK
Gilbert, Lin ; Mullard Space Science Laboratory, Department of Space & Climate Physics, University College London, London, UK
Muir, Alan; Mullard Space Science Laboratory, Department of Space & Climate Physics, University College London, London, UK ; Centre for Polar Observation and Modelling, Department of Earth Sciences, University College London, London, UK
Munneke, Peter Kuipers; Institute for Marine and Atmospheric research Utrecht, Utrecht University, Utrecht, the Netherlands
Noël, Brice ; Université de Liège - ULiège > Département de géographie > Climatologie et Topoclimatologie ; Université de Liège - ULiège > Sphères
Fettweis, Xavier ; Université de Liège - ULiège > Département de géographie > Climatologie et Topoclimatologie
van den Broeke, Michiel ; Institute for Marine and Atmospheric research Utrecht, Utrecht University, Utrecht, the Netherlands
Briggs, Kate; Centre for Polar Observation and Modelling, School of Earth and Environment, University of Leeds, Leeds, UK
Language :
English
Title :
Increased variability in Greenland Ice Sheet runoff from satellite observations.
Publication date :
01 November 2021
Journal title :
Nature Communications
eISSN :
2041-1723
Publisher :
Nature Research, England
Volume :
12
Issue :
1
Pages :
6069
Peer reviewed :
Peer Reviewed verified by ORBi
Tags :
CÉCI : Consortium des Équipements de Calcul Intensif Tier-1 supercomputer
This work was supported by NERC through National Capability funding, undertaken by a partnership between the Centre for Polar Observation Modelling and the British Antarctic Survey, and by the European Space Agency’s Polar + Earth Observation for Mass Balance study (4000132154/20/I-EF). M.M. was supported by the Lancaster University-UKCEH Centre of Excellence in Environmental Data Science. A.L was supported by the NERC Meltwater Ice-sheet Interactions and the changing climate of Greenland research grant (MII Greenland NE/S011390/1). B.N. was funded by NWO VENI grant VI.Veni.192.019. M.v.d.B and P.K.M. acknowledge support from the Netherlands Earth System Science Centre (NESSC). Computational resources used to perform MAR simulations have been provided by the Consortium des Équipements de Calcul Intensif (CÉCI), funded by the F.R.S. FNRS under grant 2.5020.11 and the Tier-1 supercomputer (Zenobe) of the Féd-ération Wallonie Bruxelles infrastructure funded by the Walloon Region under grant agreement 1117545. We thank H. Goelzer for providing modelled ice thickness change data used in Supplementary Fig. 5. We acknowledge C. Greene for several MATLAB functions provided in the Climate Data Toolbox, used in visualising the data.
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