HR: 15:25h
AN: C43A-08    [Abstracts]
TI: Benchmark Experiments for Higher-Order and Full Stokes Ice Sheet Models
AU: * Pattyn, F
EM: fpattyn@ulb.ac.be
AF: Laboratoire de Glaciologie, DSTE, Université Libre de Bruxelles, CP 160/03, Av. F.D. Roosevelt 50, Brussels, 1050, Belgium
AU: Perichon, L
EM: lpericho@ulb.ac.be
AF: Laboratoire de Glaciologie, DSTE, Université Libre de Bruxelles, CP 160/03, Av. F.D. Roosevelt 50, Brussels, 1050, Belgium
AU: Aschwanden, A
EM: andy@env.ethz.ch
AF: ETH Zurich, Universitaetstrasse, Zurich, 8092, Switzerland
AU: Breuer, B
EM: b.breuer@uni-muenster.de
AF: University of Muenster, Corrensstrasse, Muenster, 48149, Germany
AU: De Smedt, B
EM: bdesmedt@vub.ac.be
AF: Vrije Universiteit Brussel, Pleinlaan 2, Brussels, 1050, Belgium
AU: Gagliardini, O
EM: gagliar@lgge.obs.ujf-grenoble.fr
AF: LGGE, Rue Molière 54, Saint Martin d'Hères, 38402, France
AU: Gudmundsson, H
EM: ghg@bas.ac.uk
AF: British Antarctic Survey, High Cross, Cambridge, CB3 0ET, United Kingdom
AU: Hindmarsh, R
EM: rcah@bas.ac.uk
AF: British Antarctic Survey, High Cross, Cambridge, CB3 0ET, United Kingdom
AU: Hubbard, A
EM: ahubbard@geo.ed.ac.uk
AF: Institute of Geography, The University of Wales, Aberystwyth, SY23 3DB, United Kingdom
AU: Johnson, J V
EM: johnson@cs.umt.edu
AF: University of Montana, Social Science Building Room 417, Missoula, MT 59812-5256, United States
AU: Kleiner, T
EM: tkleiner@gmx.de
AF: University of Muenster, Corrensstrasse, Muenster, 48149, Germany
AU: Konovalov, Y
EM: yu-v-k@yandex.ru
AF: Engineering Physics Institute, Moscow, Moscow, 00000, Russian Federation
AU: Martin, C
EM: cama@bas.ac.uk
AF: British Antarctic Survey, High Cross, Cambridge, CB3 0ET, United Kingdom
AU: Payne, A J
EM: A.J.Payne@bristol.ac.uk
AF: Bristol Glaciology Centre, University of Bristol, Bristol, BS8 1SS, United Kingdom
AU: Pollard, D
EM: pollard@essc.psu.edu
AF: Pennsylvania State University, Earth-Engineering Sciences Bldg., University Park, PA 16802, United States
AU: Price, S
EM: s.f.price@bristol.ac.uk
AF: Bristol Glaciology Centre, University of Bristol, Bristol, BS8 1SS, United Kingdom
AU: Rueckamp, M
EM: b.breuer@uni-muenster.de
AF: University of Muenster, Corrensstrasse, Muenster, 48149, Germany
AU: Saito, F
EM: saitofuyuki@jamstec.go.jp
AF: Frontier Research Center, Kanazawa-ku, Yokohama City, 236-0001, Japan
AU: Soucek, O
EM: ondrej.soucek@mff.cuni.cz
AF: University Prague, Holesovickach 2, Praha 8, 18000, Czech Republic
AU: Sugiyama, S
EM: sugishin@lowtem.hokudai.ac.jp
AF: Hokkaido University, Nishi-8, Kita-19, Sapporo, 060-0819, Japan
AU: Zwinger, T
EM: thomas.zwinger@csc.fi
AF: CSC Ltd., P.O. Box 405, Espoo, 02101, Finland
AB: The ISMIP-HOM intercomparison exercise, launched in 2006, aims at comparing so-called higher-order ice sheet models to analytical solutions and at setting out a benchmark for such models. Higher-order models are models that incorporate further mechanical effects, principally longitudinal stress gradients, or the full Stokes system. These stresses become increasingly important in transition zones between ice sheets and ice shelves (ice streams), but also at the ice divide and in areas of complex basal topography. The proposed experiments are made accessible for a variety of model types, i.e. flowline models, vertically integrated planform models, as well as full three-dimensional models. The experiments are valid for both finite difference (FD) and finite element (FE) models. Furthermore, the grid type (regular or not) is unimportant. All thermomechanical effects are neglected and an isotherm ice mass is considered. Experiments include ideal geometry tests as well as a real case experiment on Haut Glacier d'Arolla. Most experiments are diagnostic, i.e. time evolution is not considered. This means that for a given geometry of the ice mass, a Glen-type flow law, and given appropriate boundary conditions, the stress and velocity field can be calculated. One experiment considers time-dependent response (the experiment is run until the free surface and velocity field reach a steady state) for a constant viscosity (linear flow law). For this experiment analytical solutions exist that are developed by Gudmundsson (2003). 28 numerical models of varying physical complexity participated in the exercise. The results show a very good convergence of the different models at different resolutions. At higher resolutions – and conform theory – a clear distinction can be made between higher-order models and those that solve the full system of equations (full Stokes models). The model results seem not to be influenced by the used numerical approaches, which is clearly demonstrated by the comparison of the different full Stokes models.
DE: 0798 Modeling
SC: Cryosphere [C]
MN: 2007 Fall Meeting