Results of the Marine Ice Sheet Model Intercomparison Project, MISMIP

• Published in: The Cryosphere
• Main Authors: Pattyn, F., Schoof, C., Perichon, L., Hindmarsh, R. C. A., Bueler, E., de Fleurian, B., Durand, Geoffroy, Gagliardini, O., Gladstone, R., Goldberg, D., Gudmundsson, G. H., Huybrechts, P., Lee, V., Nick, F. M., Payne, A. J., Pollard, D., Rybak, O., Saito, F., Vieli, A.
• Other Authors: Laboratoire de Glaciologie, Université libre de Bruxelles (ULB), Department of Earth and Ocean Sciences Vancouver, University of British Columbia (UBC), British Antarctic Survey (BAS), Natural Environment Research Council (NERC), Department of Mathematics and Geophysical Institute, University of Alaska Anchorage, Laboratoire de glaciologie et géophysique de l'environnement (LGGE), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), School of Geographical Sciences Bristol, University of Bristol Bristol, Courant Institute of Mathematical Sciences New York (CIMS), New York University New York (NYU), NYU System (NYU)-NYU System (NYU), Earth System Sciences & Department of Geography, Vrije Universiteit Brussel (VUB), Institute for Marine and Atmospheric Research Utrecht (IMAU), Utrecht University Utrecht, Earth and Environmental Systems Institute, Pennsylvania State University (Penn State), Penn State System-Penn State System, Frontier Research Center for Global Change (FRCGC), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Department of Geography, Durham University, IceCube-Dyn, European Project: 226375,EC:FP7:ENV,FP7-ENV-2008-1,ICE2SEA(2009)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2012
• Subjects: [SDU.STU]Sciences of the Universe [physics]/Earth Sciences; Ice Sheet; The Cryosphere
• Online Access: https://hal-insu.archives-ouvertes.fr/insu-00844423; https://hal-insu.archives-ouvertes.fr/insu-00844423/document; https://hal-insu.archives-ouvertes.fr/insu-00844423/file/tc-6-573-2012.pdf; https://doi.org/10.5194/tc-6-573-2012

International audience 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.