Parameterization of Basal Friction Near Grounding Lines in a One-Dimensional Ice Sheet Model

TitleParameterization of Basal Friction Near Grounding Lines in a One-Dimensional Ice Sheet Model
Publication TypeJournal Article
Year of Publication2014
JournalThe Cryosphere
Pages1239-1259
Date Published07/2014
Abstract / Summary

Ice sheets and ice shelves are linked by the transi- tion zone, the region where flow dominated by vertical shear stress makes a transition to flow dominated by extensional stress. Adequate resolution of the transition zone is necessary for numerically accurate ice sheet–ice shelf simulations. The required resolution depends on how the basal physics is pa- rameterized. We propose a new, simple parameterization of the effective pressure near the grounding line, combined with an existing friction law linking effective pressure to basal stress and sliding, in a one-dimensional, fixed-grid, vertically integrated model. This parameterization represents connec- tivity between the basal hydrological system and the ocean in the transition zone. Our model produces a smooth transition between finite basal friction in the ice sheet and zero basal friction in the ice shelf. In a set of experiments based on the Marine Ice Sheet Model Intercomparison Project (MISMIP), we show that with a smoother basal shear stress, the model yields accurate steady-state results at a fixed-grid resolution of about 1km.

 

URLhttp://www.the-cryosphere.net/8/1239/2014/
DOI10.5194
Journal: The Cryosphere
Year of Publication: 2014
Pages: 1239-1259
Date Published: 07/2014

Ice sheets and ice shelves are linked by the transi- tion zone, the region where flow dominated by vertical shear stress makes a transition to flow dominated by extensional stress. Adequate resolution of the transition zone is necessary for numerically accurate ice sheet–ice shelf simulations. The required resolution depends on how the basal physics is pa- rameterized. We propose a new, simple parameterization of the effective pressure near the grounding line, combined with an existing friction law linking effective pressure to basal stress and sliding, in a one-dimensional, fixed-grid, vertically integrated model. This parameterization represents connec- tivity between the basal hydrological system and the ocean in the transition zone. Our model produces a smooth transition between finite basal friction in the ice sheet and zero basal friction in the ice shelf. In a set of experiments based on the Marine Ice Sheet Model Intercomparison Project (MISMIP), we show that with a smoother basal shear stress, the model yields accurate steady-state results at a fixed-grid resolution of about 1km.

 

DOI: 10.5194
Citation:
2014.  "Parameterization of Basal Friction Near Grounding Lines in a One-Dimensional Ice Sheet Model."  The Cryosphere 1239-1259.  https://doi.org/10.5194.