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

• Published in: Geoscientific Model Development
• Main Authors: Brinkerhoff, Douglas, Johnson, Jesse
• Format: Text
• Language: unknown
• Published: ScholarWorks at University of Montana 2015
• Subjects: Computer Sciences; Greenland; Ice Sheet
• Online Access: https://scholarworks.umt.edu/cs_pubs/29; https://doi.org/10.5194/gmd-8-1275-2015; https://scholarworks.umt.edu/context/cs_pubs/article/1029/viewcontent/A.pdf

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.