Journal cover Journal topic
The Cryosphere An interactive open-access journal of the European Geosciences Union
The Cryosphere, 11, 2213-2229, 2017
https://doi.org/10.5194/tc-11-2213-2017
© Author(s) 2017. This work is distributed under
the Creative Commons Attribution 3.0 License.
Research article
18 Sep 2017
Regional modeling of the Shirase drainage basin, East Antarctica: full Stokes vs. shallow ice dynamics
Hakime Seddik1, Ralf Greve1, Thomas Zwinger2, and Shin Sugiyama1 1Institute of Low Temperature Science, Hokkaido University, Kita-19, Nishi-8, Kita-ku, Sapporo 060-0819, Japan
2CSC – IT Center for Science, P.O. Box 405, 02101 Espoo, Finland
Abstract. A hierarchy of approximations of the force balance for the flow of grounded ice exists, ranging from the most sophisticated full Stokes (FS) formulation to the most simplified shallow ice approximation (SIA). Both are implemented in the ice flow model Elmer/Ice, and we compare them by applying the model to the East Antarctic Shirase drainage basin. First, we apply the control inverse method to infer the distribution of basal friction with FS. We then compare FS and SIA by simulating the flow of the drainage basin under present-day conditions and for three scenarios 100 years into the future defined by the SeaRISE (Sea-level Response to Ice Sheet Evolution) project. FS reproduces the observed flow pattern of the drainage basin well, in particular the zone of fast flow near the grounding line, while SIA generally overpredicts the surface velocities. As for the transient scenarios, the ice volume change (relative to the constant-climate control run) of the surface climate experiment is nearly the same for FS and SIA, while for the basal sliding experiment (halved basal friction), the ice volume change is  ∼  30 % larger for SIA than for FS. This confirms findings of earlier studies that, in order to model ice sheet areas containing ice streams and outlet glaciers with high resolution and precision, careful consideration must be given to the choice of a suitable force balance.

Citation: Seddik, H., Greve, R., Zwinger, T., and Sugiyama, S.: Regional modeling of the Shirase drainage basin, East Antarctica: full Stokes vs. shallow ice dynamics, The Cryosphere, 11, 2213-2229, https://doi.org/10.5194/tc-11-2213-2017, 2017.
Publications Copernicus
Download
Short summary
The Shirase Glacier in Antarctica is studied by means of a computer model. This model implements two physical approaches to represent the glacier flow dynamics. This study finds that it is important to use the more precise and sophisticated method in order to better understand and predict the evolution of fast flowing glaciers. This may be important to more accurately predict the sea level change due to global warming.
The Shirase Glacier in Antarctica is studied by means of a computer model. This model implements...
Share