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| Titel |
Hydrostatic grounding line parameterization in ice sheet models |
| VerfasserIn |
H. Seroussi, M. Morlighem, E. Larour, E. Rignot, A. Khazendar |
| 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. 6 ; Nr. 8, no. 6 (2014-11-17), S.2075-2087 |
| Datensatznummer |
250116376
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| Publikation (Nr.) |
 copernicus.org/tc-8-2075-2014.pdf |
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| Zusammenfassung |
| Modeling of grounding line migration is essential to accurately simulate the
behavior of marine ice sheets and investigate their stability. Here, we
assess the sensitivity of numerical models to the parameterization of the
grounding line position. We run the MISMIP3D benchmark experiments using the
Ice Sheet System Model (ISSM) and a two-dimensional shelfy-stream approximation (SSA) model with different mesh
resolutions and different sub-element parameterizations of grounding line
position. Results show that different grounding line parameterizations lead
to different steady state grounding line positions as well as different
retreat/advance rates. Our simulations explain why some vertically
depth-averaged model simulations deviate significantly from the vast majority
of simulations based on SSA in the MISMIP3D benchmark. The results reveal
that differences between simulations performed with and without sub-element
parameterization are as large as those performed with different
approximations of the stress balance equations in this configuration. They
also demonstrate that the reversibility test is passed at relatively coarse
resolution while much finer resolutions are needed to accurately capture the
steady-state grounding line position. We conclude that fixed grid SSA models
that do not employ such a parameterization should be avoided, as they do not
provide accurate estimates of grounding line dynamics, even at high spatial
resolution. For models that include sub-element grounding line
parameterization, in the MISMIP3D configuration, a mesh resolution finer than
2 km should be employed. |
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