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Rapid loss of firn pore space accelerates 21st century Greenland mass loss
Author(s) -
van Angelen J. H.,
M. Lenaerts J. T.,
van den Broeke M. R.,
Fettweis X.,
Meijgaard E.
Publication year - 2013
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/grl.50490
Subject(s) - meltwater , firn , greenland ice sheet , glacier , geology , glacier mass balance , ice sheet , ice stream , future sea level , climatology , sea ice , atmospheric sciences , environmental science , geomorphology , cryosphere
Abstract Mass loss from the two major ice sheets and their contribution to global sea level rise is accelerating. In Antarctica, mass loss is dominated by increased flow velocities of outlet glaciers, following the thinning or disintegration of coastal ice shelves into which they flow. In contrast, ~55% of post‐1992 Greenland ice sheet (GrIS) mass loss is accounted for by surface processes, notably increased meltwater runoff. A subtle process in the surface mass balance of the GrIS is the retention and refreezing of meltwater, currently preventing ~40% of the meltwater to reach the ocean. Here we force a high‐resolution atmosphere/snow model with a mid‐range warming scenario (RCP4.5, 1970–2100), to show that rapid loss of firn pore space, by >50% at the end of the 21st century, quickly reduces this refreezing buffer. As a result, GrIS surface mass loss accelerates throughout the 21st century and its contribution to global sea level rise increases to 1.7 ±0.5 mm yr −1 , more than four times the current value.