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| Titel |
Results of the Marine Ice Sheet Model Intercomparison Project, MISMIP |
| VerfasserIn |
F. Pattyn, C. Schoof, L. Perichon, R. C. A. Hindmarsh, E. Bueler, B. Fleurian, G. Durand, O. Gagliardini, R. Gladstone, D. Goldberg, G. H. Gudmundsson, P. Huybrechts, V. Lee, F. M. Nick, A. J. Payne, D. Pollard, O. Rybak, F. Saito, A. Vieli |
| 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 ; 6, no. 3 ; Nr. 6, no. 3 (2012-05-30), S.573-588 |
| Datensatznummer |
250003592
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| Publikation (Nr.) |
 copernicus.org/tc-6-573-2012.pdf |
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| Zusammenfassung |
| Predictions of marine ice-sheet behaviour require models that are able
to robustly simulate grounding line migration. We present results of
an intercomparison exercise for marine ice-sheet models. Verification
is effected by comparison with approximate analytical solutions for
flux across the grounding line using simplified geometrical
configurations (no lateral variations, no effects of lateral
buttressing). Unique steady state grounding line positions exist for
ice sheets on a downward sloping bed, while hysteresis occurs across
an overdeepened bed, and stable steady state grounding line positions
only occur on the downward-sloping sections. Models based on the
shallow ice approximation, which does not resolve extensional
stresses, do not reproduce the approximate analytical results unless
appropriate parameterizations for ice flux are imposed at the
grounding line. For extensional-stress resolving "shelfy stream"
models, differences between model results were mainly due to the
choice of spatial discretization. Moving grid methods were found to be
the most accurate at capturing grounding line evolution, since they
track the grounding line explicitly. Adaptive mesh refinement can
further improve accuracy, including fixed grid models that
generally perform poorly at coarse resolution. Fixed grid models, with
nested grid representations of the grounding line, are able to generate
accurate steady state positions, but can be inaccurate over
transients. Only one full-Stokes model was included in the
intercomparison, and consequently the accuracy of shelfy stream models
as approximations of full-Stokes models remains to be determined in
detail, especially during transients. |
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