Journal cover Journal topic
Geoscientific Model Development An interactive open-access journal of the European Geosciences Union
https://doi.org/10.5194/gmd-2017-312
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.
Development and technical paper
07 Feb 2018
Review status
This discussion paper is a preprint. It is a manuscript under review for the journal Geoscientific Model Development (GMD).
Dynamically coupling Full Stokes and Shallow Shelf Approximation for marine ice sheet flow using Elmer/Ice (v8.3)
Eef C. H. van Dongen1,2,3,4, Nina Kirchner2,5, Martin B. van Gijzen3, Roderik S. W. van de Wal4, Thomas Zwinger6, Gong Cheng5,7, Per Lötstedt5,7, and Lina von Sydow5,7 1Laboratory of Hydraulics, Hydrology and Glaciology, ETHZ, Zurich, Switzerland
2Department of Physical Geography, Stockholm University, Stockholm, Sweden
3Department of Applied Mathematical Analysis, Delft University of Technology, Delft, The Netherlands
4Institute for Marine and Atmospheric Research Utrecht, Utrecht University, The Netherlands
5Bolin Centre for Climate Research, Stockholm University, Stockholm, Sweden
6CSC-IT Center for Science, Espoo, Finland
7Division of Scientific Computing, Department of Information Technology, Uppsala University, Uppsala, Sweden
Abstract. Ice flow forced by gravity is governed by the Full Stokes (FS) equations, which are computationally expensive to solve due to their non-linearity introduced by the rheology. Therefore, approximations to the FS equations are used, especially when modelling an ice sheet complex (ice sheet, ice shelf and/or ice stream) on the order of 1000 years or longer. The Shallow Ice Approximation (SIA) and Shallow Shelf Approximation (SSA) are commonly used but are accurate only in certain parts of an ice sheet. Here, we report on a novel way of iteratively coupling FS and SSA that has been implemented in Elmer/Ice and applied to conceptual marine ice sheets. The FS-SSA coupling appears to be very accurate; the relative error in velocity compared to FS is below 0.5 % for diagnostic and below 5 % for prognostic runs. Results for grounding line dynamics obtained with the FS-SSA coupling are similar to results obtained from a FS model in an experiment with a periodical temperature forcing over 3000 years inducing grounding line advance and retreat. The rapid convergence of the FS-SSA coupling shows a large potential in reducing computation time, such that modelling an ice sheet complex for thousands of years should become feasible in the near future. Despite inefficient matrix assembly in the current implementation, computation time is reduced significantly, i.e. by 32 %, when the coupling is applied to a 3D ice shelf. In the future, the FS-SSA coupling can be extended to include a SIA-FS coupling of ISCAL (Ice Sheet Coupled Approximation Level)-type.

Citation: van Dongen, E. C. H., Kirchner, N., van Gijzen, M. B., van de Wal, R. S. W., Zwinger, T., Cheng, G., Lötstedt, P., and von Sydow, L.: Dynamically coupling Full Stokes and Shallow Shelf Approximation for marine ice sheet flow using Elmer/Ice (v8.3), Geosci. Model Dev. Discuss., https://doi.org/10.5194/gmd-2017-312, in review, 2018.
Eef C. H. van Dongen et al.
Eef C. H. van Dongen et al.
Eef C. H. van Dongen et al.

Viewed

Total article views: 208 (including HTML, PDF, and XML)

HTML PDF XML Total BibTeX EndNote
172 29 7 208 1 8

Views and downloads (calculated since 07 Feb 2018)

Cumulative views and downloads (calculated since 07 Feb 2018)

Viewed (geographical distribution)

Total article views: 206 (including HTML, PDF, and XML)

Thereof 206 with geography defined and 0 with unknown origin.

Country # Views %
  • 1

Saved

Discussed

Latest update: 24 Feb 2018
Publications Copernicus
Download
Short summary
Ice flow forced by gravity is governed by the Full Stokes (FS) equations, which are computationally expensive to solve. Therefore, approximations to the FS equations are used, especially when modelling an ice sheet on long time spans. Here, we report on a combination of an approximation with the FS equations, allowing to simulate the dynamics of ice sheets over long time spans without introducing artifacts caused by application of approximations in parts of the domain where they are not valid.
Ice flow forced by gravity is governed by the Full Stokes (FS) equations, which are...
Share