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Titel |
The impact of Saharan dust and black carbon on albedo and long-term mass balance of an Alpine glacier |
VerfasserIn |
J. Gabbi, M. Huss, A. Bauder, F. Cao, M. Schwikowski |
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. 4 ; Nr. 9, no. 4 (2015-07-30), S.1385-1400 |
Datensatznummer |
250116823
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Publikation (Nr.) |
copernicus.org/tc-9-1385-2015.pdf |
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Zusammenfassung |
Light-absorbing impurities in snow and ice control glacier melt as shortwave radiation represents the main component
of the surface energy balance. Here, we investigate the long-term effect of snow impurities, i.e., mineral dust and
black carbon (BC), on albedo and glacier mass balance. The analysis was performed over the period 1914–2014 for two
sites on Claridenfirn, Swiss Alps, where an outstanding 100-year record of seasonal mass balance measurements is
available. Information on atmospheric deposition of mineral dust and BC over the last century was retrieved from two
firn/ice cores of high-alpine sites. A combined mass balance and snow/firn layer model was employed to assess the
effects of melt and accumulation processes on the impurity concentration at the surface and thus on albedo
and glacier mass balance. Compared to pure snow conditions, the presence of Saharan dust and BC lowered the mean annual
albedo by 0.04–0.06 depending on the location on the glacier. Consequently, annual melt was increased by 15–19 %, and
the mean annual mass balance was reduced by about 280–490 mm w.e. BC clearly dominated absorption which is
about 3 times higher than that of mineral dust. The upper site has experienced mainly positive mass balances and
impurity layers were continuously buried whereas at the lower site, surface albedo was more strongly influenced by
re-exposure of dust and BC-enriched layers due to frequent years with negative mass balances. |
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