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| Titel |
Numerical simulations and observations of the role of katabatic winds in the creation and maintenance of Scharffenbergbotnen blue ice area, Antarctica |
| VerfasserIn |
T. Zwinger, T. Malm, M. Schäfer, R. Stenberg, J. C. Moore |
| 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 (2015-08-04), S.1415-1426 |
| Datensatznummer |
250116825
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| Publikation (Nr.) |
 copernicus.org/tc-9-1415-2015.pdf |
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| Zusammenfassung |
| We model the role of katabatic winds in the formation and maintenance of a
blue ice area in Scharffenbergbotnen valley, Antarctica, using the finite
element code Elmer. The high-horizontal-resolution (50–200 m)
numerical simulations of the local wind flow from katabatic wind fronts show
high spatial variability in wind-impact patterns and good congruence between
places with high near-surface wind speeds and the blue ice area. In addition
we perform wind simulations on an altered glacier geometry that resembles the
thicker ice cover at the Late Glacial Maximum (LGM). These simulations
indicate that the pronounced spatial wind-impact patterns depend on present-day geometry and did not occur during the LGM. This leads to the conclusion
that the formation of the inner blue ice area of the Scharffenbergbotnen
valley started only after the lowering of the ice surface, i.e. after the
LGM. Experiments with smoothed surface topography suggest that detailed
positions of the high wind regions, and hence individual blue ice fields, may
have varied as the ice sheet lowered. The simulation results obtained with
the present-day geometry were fortuitously confirmed by the destruction of a
field camp located in a high-wind-speed area and its subsequent
redistribution to low-velocity areas. The experiments and the field
observations are consistent with localized violent katabatic events rather
than synoptic-scale storms, playing the dominant role in the formation and
maintenance of this and perhaps many blue ice areas. |
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