A tipping point in refreezing accelerates mass loss of Greenland's glaciers and ice caps

A tipping point in refreezing accelerates mass loss of Greenland's glaciers and ice caps

Noël, Brice (Universiteit Utrecht)
van den Berg, J.W. (Universiteit Utrecht)
Lhermitte, S.L.M. (TU Delft Mathematical Geodesy and Positioning)
Wouters, B. (Universiteit Utrecht)
Machguth, Horst (University of Zürich; University of Fribourg; Geological Survey of Denmark and Greenland)
Howat, Ian (Ohio State University)
Citterio, M. (Geological Survey of Denmark and Greenland)
Moholdt, G (Fram Centre)
Lenaerts, Jan T M (Universiteit Utrecht)
van den Broeke, Michiel R. (Universiteit Utrecht)

2017-03-31

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.

http://resolver.tudelft.nl/uuid:c46b693a-77f6-4225-9440-8f888ff58cb3

https://doi.org/10.1038/ncomms14730

2041-1723

Nature Communications, 8

Institutional Repository

journal article

© 2017 Brice Noël, J.W. van den Berg, S.L.M. Lhermitte, B. Wouters, Horst Machguth, Ian Howat, M. Citterio, G Moholdt, Jan T M Lenaerts, Michiel R. van den Broeke