EGU General Assembly 2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Increasing the largest stable time-step size in ice flow models

André Löfgren1, Josefin Ahlkrona1, Thomas Zwinger2, Christian Helanow1, and Denis Cohen3
André Löfgren et al.
  • 1Department of Mathematics, Stockholm University, Stockholm, Sweden
  • 2CSC - IT Center for Science Ltd., Espoo, Finland
  • 3COSCI Ltd

Ice flow models often suffer from numerical instabilities that restricts time-step sizes. For higher-order models this constitutes a severe bottleneck. We present a method for increasing the largest stable time step in full Stokes models, allowing for a significant speed-up of simulations.  This type of stabilisation was originally developed for mantle-convection simulations and is here extended to ice flow problems. The method is mimicking an implicit solver but the computational cost per time step is nearly as low as for an explicit solver. As it only consists of adding a stabilisation term to the gravitational force in the full Stokes equations, it is very easy to implement. We test the method using both Elmer/Ice and FEniCS on artificial glaciers with varying bedrock roughness, slip rate and surface inclination, as well as on a real world case.

How to cite: Löfgren, A., Ahlkrona, J., Zwinger, T., Helanow, C., and Cohen, D.: Increasing the largest stable time-step size in ice flow models, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-14849,, 2023.