A tipping point in refreezing accelerates mass loss of Greenland's glaciers and ice caps
Brice Noël (Universiteit Utrecht)
J.W. van den Berg (Universiteit Utrecht)
S. Lhermitte (TU Delft - Mathematical Geodesy and Positioning)
B. Wouters (Universiteit Utrecht)
Horst Machguth (Universitat Zurich, University of Fribourg, Geological Survey of Denmark and Greenland)
Ian Howat (The Ohio State University)
M. Citterio (Geological Survey of Denmark and Greenland)
G Moholdt (Fram Centre)
Jan T M Lenaerts (Universiteit Utrecht)
Michiel R. van den Broeke (Universiteit Utrecht)
More Info
expand_more
Other than for strictly personal use, it is not permitted to download, forward or distribute the text or part of it, without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license such as Creative Commons.
Abstract
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 -1/414% 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.
help_outline