[en] Melting of the Greenland ice sheet (GrIS) and its peripheral glaciers and ice caps (GICs) contributes about 43% to contemporary sea level rise. While patterns of GrIS mass loss are well studied, the spatial and temporal evolution of GICs mass loss and the acting processes have remained unclear. Here we use a novel, 1 km surface mass balance product, evaluated against in situ and remote sensing data, to identify 1997 (±5 years) as a tipping point for GICs mass balance. That year marks the onset of a rapid deterioration in the capacity of the GICs firn to refreeze meltwater. Consequently, GICs runoff increases 65% faster than meltwater production, tripling the post-1997 mass loss to 36±16 Gt-1, or ∼14% of the Greenland total. In sharp contrast, the extensive inland firn of the GrIS retains most of its refreezing capacity for now, buffering 22% of the increased meltwater production. This underlines the very different response of the GICs and GrIS to atmospheric warming.
Disciplines :
Earth sciences & physical geography
Author, co-author :
Noël, Brice ; Université de Liège - ULiège > Département de géographie > Climatologie et Topoclimatologie ; Institute for Marine and Atmospheric Research Utrecht, Utrecht University, 3584 CC Utrecht, The Netherlands
van de Berg, W J; Institute for Marine and Atmospheric Research Utrecht, Utrecht University, 3584 CC Utrecht, The Netherlands
Lhermitte, S ; Department of Geoscience and Remote Sensing, Delft University of Technology, 2600 AA Delft, The Netherlands
Wouters, B; Institute for Marine and Atmospheric Research Utrecht, Utrecht University, 3584 CC Utrecht, The Netherlands
Machguth, H; Department of Geography, University of Zürich, CH-8006 Zürich, Switzerland ; Department of Geosciences, University of Fribourg, CH-1700 Fribourg, Switzerland ; Geological Survey of Denmark and Greenland GEUS, 1350 København K, Denmark
Howat, I ; Byrd Polar Research Center and School of Earth Sciences and Department of Geography, Ohio State University, Columbus, Ohio 43210, USA
Citterio, M; Geological Survey of Denmark and Greenland GEUS, 1350 København K, Denmark
Moholdt, G; Norwegian Polar Institute, Fram Centre, NO-9296 Tromsø, Norway
Lenaerts, J T M; Institute for Marine and Atmospheric Research Utrecht, Utrecht University, 3584 CC Utrecht, The Netherlands
van den Broeke, M R; Institute for Marine and Atmospheric Research Utrecht, Utrecht University, 3584 CC Utrecht, The Netherlands
Language :
English
Title :
A tipping point in refreezing accelerates mass loss of Greenland's glaciers and ice caps.
Publication date :
31 March 2017
Journal title :
Nature Communications
eISSN :
2041-1723
Publisher :
Nature Publishing Group, Basingstoke, Hampshire, England
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