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Titel |
Grounding line transient response in marine ice sheet models |
VerfasserIn |
A. S. Drouet, D. Docquier, G. Durand, R. Hindmarsh, F. Pattyn, O. Gagliardini, T. Zwinger |
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. 2 ; Nr. 7, no. 2 (2013-03-01), S.395-406 |
Datensatznummer |
250017938
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Publikation (Nr.) |
copernicus.org/tc-7-395-2013.pdf |
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Zusammenfassung |
Marine ice-sheet stability is mostly controlled by the dynamics of the
grounding line, i.e. the junction between the grounded ice sheet and the
floating ice shelf. Grounding line migration has been investigated within the
framework of MISMIP (Marine Ice Sheet Model Intercomparison Project), which
mainly aimed at investigating steady state solutions. Here we focus on
transient behaviour, executing short-term simulations (200 yr) of a steady
ice sheet perturbed by the release of the buttressing restraint exerted by
the ice shelf on the grounded ice upstream. The transient grounding line
behaviour of four different flowline ice-sheet models has been compared. The
models differ in the physics implemented (full Stokes and shallow shelf
approximation), the numerical approach, as well as the grounding line
treatment. Their overall response to the loss of buttressing is found to be
broadly consistent in terms of grounding line position, rate of surface
elevation change and surface velocity. However, still small differences
appear for these latter variables, and they can lead to large discrepancies
(> 100%) observed in terms of ice sheet contribution to sea level when
cumulated over time. Despite the recent important improvements of marine ice-sheet models in their ability to compute steady state configurations, our
results question the capacity of these models to compute short-term reliable
sea-level rise projections. |
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