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| Titel |
Dynamic response of Antarctic ice shelves to bedrock uncertainty |
| VerfasserIn |
S. Sun, S. L. Cornford, Y. Liu, 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 ; 8, no. 4 ; Nr. 8, no. 4 (2014-08-21), S.1561-1576 |
| Datensatznummer |
250116267
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| Publikation (Nr.) |
 copernicus.org/tc-8-1561-2014.pdf |
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| Zusammenfassung |
| Accurate and extensive bedrock geometry data is essential in ice sheet
modelling. The shape of the bedrock on fine scales can influence ice sheet
evolution, for example through the formation of pinning points that alter
grounding line dynamics. Here we test the sensitivity of the
BISICLES
adaptive mesh ice sheet model to small-amplitude height fluctuations on
different spatial scales in the bedrock topography provided by Bedmap2 in
the catchments of Pine Island Glacier, the Amery Ice shelf and a region of
East Antarctica including the Aurora Basin, Law Dome and Totten Glacier. We
generate an ensemble of bedrock topographies by adding random noise to the
Bedmap2 data with amplitude determined by the accompanying estimates of
bedrock uncertainty. We find that the small-amplitude fluctuations result in
only minor changes in the way these glaciers evolve. However, lower-frequency noise, with a broad spatial scale (over tens of kilometres) is more important
than higher-frequency noise even when the features have the same height
amplitudes and the total noise power is maintained. This is cause for optimism
regarding credible sea level rise estimates with presently achievable density of
thickness measurements. Pine Island Glacier and the region around Totten
Glacier and Law Dome undergo substantial retreat and appear to be more
sensitive to errors in bed topography than the Amery Ice shelf region which
remains stable under the present-day observational data uncertainty. |
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