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| Titel |
Partitioning of melt energy and meltwater fluxes in the ablation zone of the west Greenland ice sheet |
| VerfasserIn |
M. Broeke, P. Smeets, J. Ettema, C. Veen, R. Wal, J. Oerlemans  |
| 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 ; 2, no. 2 ; Nr. 2, no. 2 (2008-12-08), S.179-189 |
| Datensatznummer |
250000534
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| Publikation (Nr.) |
 copernicus.org/tc-2-179-2008.pdf |
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| Zusammenfassung |
| We present four years (August 2003–August 2007) of surface mass balance data
from the ablation zone of the west Greenland ice sheet along the 67° N
latitude circle. Sonic height rangers and automatic weather stations
continuously measured accumulation/ablation and near-surface climate at
distances of 6, 38 and 88 km from the ice sheet margin at elevations of 490,
1020 and 1520 m a.s.l. Using a melt model and reasonable assumptions about
snow density and percolation characteristics, these data are used to
quantify the partitioning of energy and mass fluxes during melt episodes.
The lowest site receives very little winter accumulation, and ice melting is
nearly continuous in June, July and August. Due to the lack of snow
accumulation, little refreezing occurs and virtually all melt energy is
invested in runoff. Higher up the ice sheet, the ice sheet surface freezes
up during the night, making summer melting intermittent. At the intermediate
site, refreezing in snow consumes about 10% of the melt energy,
increasing to 40% at the highest site. The sum of these effects is that
total melt and runoff increase exponentially towards the ice sheet margin,
each time doubling between the stations. At the two lower sites, we estimate
that radiation penetration causes 20–30% of the ice melt to occur below
the surface. |
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