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| Titel |
Modeling energy and mass balance of Shallap Glacier, Peru |
| VerfasserIn |
W. Gurgiser, B. Marzeion, L. Nicholson, M. Ortner, G. Kaser  |
| 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 ; 7, no. 6 ; Nr. 7, no. 6 (2013-11-22), S.1787-1802 |
| Datensatznummer |
250085183
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| Publikation (Nr.) |
 copernicus.org/tc-7-1787-2013.pdf |
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| Zusammenfassung |
| We calculated the distributed surface mass and energy balance of
Shallap Glacier, Cordillera Blanca, Peru (9° S,
77° W, 4700–5700 m a.s.l., ~ 7 km2), on hourly time steps for two years (September
2006–August 2008) using a process-based model and meteorological
measurements as input. Model parameter combinations were optimized
against 21 temporal readings of 20 stakes in the ablation zone of
the glacier. Uncertainty caused by model input parameters and
parameterization schemes was estimated using a leave-one out
cross-validation scheme, which yields values of root mean square
deviation (RMSD) of surface height change < 1 m
(< 10% of the measured amplitude) for all stakes. With the best
parameter combination (smallest RMSD) applied, the modeled annual
surface mass balance of the glacier was −0.32 ± 0.4 m w.e. (water
equivalent)
for September 2006–August 2007 and 0.51 ± 0.56 m w.e.
for September 2007–August 2008. While the mass balance above
5000 m was similar in both years (Δ 0.33 ± 0.68 m w.e.) due to similar annual sums of solid
precipitation, a difference of 1.97 ± 0.68 m w.e. was
calculated for the lower parts of the glacier. This difference is
associated with more frequent occurrence of higher snow line
altitudes during the first year, which was mainly caused by a higher
fraction of liquid precipitation due to higher mean air
temperatures. As the net shortwave budget was found to be the main
source for ablation throughout the year at Shallap Glacier, lower
surface albedo especially caused by lower solid precipitation amounts explains most of
the difference in modeled ablation and mass balance between the two
years. |
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