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Titel |
Runoff and mass-balance simulations from the Greenland Ice Sheet at Kangerlussuaq (Søndre Strømfjord) in a 30-year perspective, 1979–2008 |
VerfasserIn |
S. H. Mernild, G. E. Liston, K. Steffen, M. Broeke, B. Hasholt |
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 ; 4, no. 2 ; Nr. 4, no. 2 (2010-06-29), S.231-242 |
Datensatznummer |
250001650
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Publikation (Nr.) |
copernicus.org/tc-4-231-2010.pdf |
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Zusammenfassung |
This study provides insights into surface mass-balance (SMB) and runoff
exiting the Watson River drainage basin, Kangerlussuaq, West Greenland
during a 30 year period (1978/1979–2007/2008) when the climate experienced
increasing temperatures and precipitation. The 30-year simulations quantify
the terrestrial freshwater output from part of the Greenland Ice Sheet
(GrIS) and the land between the GrIS and the ocean, in the context of global
warming and increasing GrIS surface melt. We used a snow-evolution modeling
system (SnowModel) to simulate the winter accumulation and summer ablation
processes, including runoff and SMB, of the ice sheet: indicating that the
simulated equilibrium line altitude (ELA) was in accordance with independent
observations. To a large extent, the SMB fluctuations could be explained by
changes in net precipitation (precipitation minus evaporation and
sublimation), with 8 out of 30 years having negative SMB, mainly because of
relatively low annual net precipitation. The overall trend in net
precipitation and runoff increased significantly, while SMB increased
insignificantly throughout the simulation period, leading to enhanced
precipitation of 0.59 km3 w.eq. (or ~60%), runoff of
0.43 km3 w.eq. (or ~55%), and SMB of 0.16 km3 w.eq. (or
~85%). Runoff rose on average from 0.80 km3 w.eq. in 1978/1979 to
1.23 km3 w.eq. in 2007/2008. The GrIS satellite-derived melt-extent increased
significantly, and the melting intensification occurred simultaneously with
the increase in local Kangerlussuaq runoff, indicating that satellite data
can be used as a proxy (r2=0.64) for runoff from the Kangerlussuaq
drainage area. |
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