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| Titel |
Evaluation of the updated regional climate model RACMO2.3: summer snowfall impact on the Greenland Ice Sheet |
| VerfasserIn |
B. Noël, W. J. van de Berg, E. van Meijgaard, P. Kuipers Munneke, R. S. W. van de Wal, 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. 5 ; Nr. 9, no. 5 (2015-09-18), S.1831-1844 |
| Datensatznummer |
250116851
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| Publikation (Nr.) |
 copernicus.org/tc-9-1831-2015.pdf |
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| Zusammenfassung |
| We discuss Greenland Ice Sheet (GrIS) surface mass balance (SMB) differences
between the updated polar version of the RACMO climate model (RACMO2.3) and
the previous version (RACMO2.1). Among other revisions, the updated model
includes an adjusted rainfall-to-snowfall conversion that produces
exclusively snowfall under freezing conditions; this especially favours
snowfall in summer. Summer snowfall in the ablation zone of the GrIS has a
pronounced effect on melt rates, affecting modelled GrIS SMB in two ways. By
covering relatively dark ice with highly reflective fresh snow, these summer
snowfalls have the potential to locally reduce melt rates in the ablation
zone of the GrIS through the snow-albedo-melt feedback. At larger scales, SMB
changes are driven by differences in orographic precipitation following a
shift in large-scale circulation, in combination with enhanced moisture to
precipitation conversion for warm to moderately cold conditions. A detailed
comparison of model output with observations from automatic weather stations,
ice cores and ablation stakes shows that the model update generally improves
the simulated SMB-elevation gradient as well as the representation of the
surface energy balance, although significant biases remain. |
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