A stabilized finite element method for calculating balance velocities in ice sheets

• Published in: Geoscientific Model Development
• Main Authors: D. Brinkerhoff, J. Johnson
• Format: Article in Journal/Newspaper
• Language: English
• Published: Copernicus Publications 2015
• Subjects: Geology; QE1-996.5; Greenland; Ice Sheet
• Online Access: https://doi.org/10.5194/gmd-8-1275-2015; https://doaj.org/article/647ad0718db844598e862dc4a9f365fa

We present a numerical method for calculating vertically averaged velocity fields using a mass conservation approach, commonly known as balance velocities. This allows for an unstructured grid, is not dependent on a heuristic flow routing algorithm, and is both parallelizable and efficient. We apply the method to calculate depth-averaged velocities of the Greenland Ice Sheet, and find that the method produces grid-independent velocity fields for a sufficient parameterization of horizontal plane stresses on flow directions. We show that balance velocity can be used as the forward model for a constrained optimization problem that can be used to fill gaps and smooth strong gradients in InSAR velocity fields.