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| Titel |
Elevation change of the Greenland Ice Sheet due to surface mass balance and firn processes, 1960–2014 |
| VerfasserIn |
P. Kuipers Munneke, S. R. M. Ligtenberg, B. P. Y. Noël, I. M. Howat, J. E. Box, E. Mosley-Thompson, J. R. McConnell, K. Steffen, J. T. Harper, S. B. Das, M. R. van den Broeke |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1994-0416
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| Digitales Dokument |
URL |
| Erschienen |
In: The Cryosphere ; 9, no. 6 ; Nr. 9, no. 6 (2015-11-02), S.2009-2025 |
| Datensatznummer |
250116863
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| Publikation (Nr.) |
 copernicus.org/tc-9-2009-2015.pdf |
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| Zusammenfassung |
| Observed changes in the surface elevation of the Greenland Ice Sheet are
caused by ice dynamics, basal elevation change, basal melt, surface mass
balance (SMB) variability, and by compaction of the overlying firn. The
last two contributions are quantified here using a firn model that includes
compaction, meltwater percolation, and refreezing. The model is forced with
surface mass fluxes and temperature from a regional climate model for the
period 1960–2014. The model results agree with observations of surface
density, density profiles from 62 firn cores, and altimetric observations
from regions where ice-dynamical surface height changes are likely small. In
areas with strong surface melt, the firn model overestimates density. We find
that the firn layer in the high interior is generally thickening slowly
(1–5 cm yr−1). In the percolation and ablation areas, firn and SMB
processes account for a surface elevation lowering of up to
20–50 cm yr−1. Most of this firn-induced marginal thinning is caused
by an increase in melt since the mid-1990s and partly compensated by an
increase in the accumulation of fresh snow around most of the ice sheet. The
total firn and ice volume change between 1980 and 2014 is estimated at
−3295 ± 1030 km3 due to firn and SMB changes, corresponding to
an ice-sheet average thinning of 1.96 ± 0.61 m. Most of this volume
decrease occurred after 1995. The computed changes in surface elevation can
be used to partition altimetrically observed volume change into surface mass
balance and ice-dynamically related mass changes. |
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