Université de Fribourg

Firn data compilation reveals widespread decrease of firn air content in western Greenland

Vandecrux, Baptiste ; MacFerrin, Michael ; Machguth, Horst ; Colgan, William T. ; As, Dirk van ; Heilig, Achim ; Stevens, C. Max ; Charalampidis, Charalampos ; Fausto, Robert S. ; Morris, Elizabeth M. ; Mosley-Thompson, Ellen ; Koenig, Lora ; Montgomery, Lynn N. ; Miège, Clément ; Simonsen, Sebastian B. ; Ingeman-Nielsen, Thomas ; Box, Jason E.

In: The Cryosphere, 2019, vol. 13, no. 3, p. 845–859

The perennial snow, or firn, on the Greenland ice sheet each summer stores part of the meltwater formed at the surface, buffering the ice sheet’s contribution to sea level. We gathered observations of firn air content, indicative of the space available in the firn to retain meltwater, and find that this air content remained stable in cold regions of the firn over the last 65 years but...

Université de Fribourg

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

Noël, B. ; Berg, W. J van de ; Lhermitte, S. ; Wouters, B. ; Machguth, Horst ; Howat, I. ; Citterio, M. ; Moholdt, G. ; Lenaerts, J. T. M. ; Broeke, M. R. van den

In: Nature Communications, 2017, vol. 8, p. 14730

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...

Université de Fribourg

The abandoned ice sheet base at Camp Century, Greenland, in a warming climate

Colgan, William ; Machguth, Horst ; MacFerrin, Mike ; Colgan, Jeff D. ; As, Dirk van ; MacGregor, Joseph A.

In: Geophysical Research Letters, 2016, vol. 43, no. 15, p. 8091–8096

In 1959 the U.S. Army Corps of Engineers built Camp Century beneath the surface of the northwestern Greenland Ice Sheet. There they studied the feasibility of deploying ballistic missiles within the ice sheet. The base and its wastes were abandoned with minimal decommissioning in 1967, under the assumption they would be preserved for eternity by perpetually accumulating snowfall. Here we show...