Repository and Documentation for Glaciological Source Code

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This page is meant as a central point of distributing special code to ice simulation problems. For the time being, we do not want to include this code within the main SVN repository. On this page we also try to add a little bit of documentation to the code.

Modules for Elmer

Code specifically tailored to meet with needs for Glaciological modeling:

  • TemperateIceSolver: solves the variational inequality for heat transfer imposed by the upper limit of the pressure melting point for the temperature
  • FlowDepthSolver: solves for the flow depth/height from the free surface/bedrock in vertical direction. This is a non-trivial problem in unstructured FEM meshes!
  • ComputeDevStressNS: computes the stress from a given velocity field and viscosity (by default from the Navier Stokes solver). This solver needs normal computed normal vectors
  • ComputeNormal: computes normal vectors at indicated boundary points as an average value of the boundary element normal vectors
  • IceFlowProperties: Collection of useful routines for ice flow problems (Material parameters, boundary condition, etc.)
  • AIFlow: Anisotropic ice flow with a General Orthotropic (Linear) ice Flow model
  • USFSliding: Weertman sliding law

Auxiliary Code

Code needed for setting up simulations. E.g., obtaining a regular Elmer mesh from a digital elevation model (DEM):

  • ExtrudeMesh: extrudes a 2D footprint to a layered 3D mesh. Optionally, a bedrock as well as a free surface DEM can be used for interpolation
  • ElmerDEM: Creates an Elmer-readable mesh on a (bedrock,thicknes,surface) DEM (untested)

Solver Input File Sections

This contains certain hints on solutions for Glaciological problems from within the SIF (Solver Input File), such as Glen's flow law, definition of the pressure melting point and temperature dependent material parameters. Also sections on how to use solvers that are part of the main Elmer distribution can be utilized for certain purposes, such as computing the depth-age solution.

  • Glen's flow law: Glen's flow law as built-in function and as MATC function
  • Thermodynamic Properties: Heat conductivity and capacity as well as pressure melting point as MATC functions
  • Geometry related issues: longitude and latitude as function of Cartesian coordinates; implementation of a prognostic free surface problem
  • Age/Depth Relation: the age/depth function is a hyperbolic PDE, hence in need of a special numerical treatment, the Discontinuous Galerkin (DG) method
  • Normal Velocity: inquiring the normal velocity and (by the sign) its principle direction in- or outwards

--Tzwinger 07:34, 1 October 2009 (UTC)