Solver Calving2D
Solver Fortran File: Calving.F90
Solver Name: Find_Calving
Required Output Variable(s): Height
Required Input Variable(s): List of Vars to interpolate (see example)
Optional Output Variable(s):
Optional Input Variable(s): List of vars to nullify (set to zero)
General Description
This is the solver for calving in 2D. It doesn't really solve any PDEs, but rather predicts if and where calving will occur, based on the 'crevasse depth calving law'. The crevasse depth calving law works by identifying connected groups of nodes where either surface or basal crevasses are predicted to be open based on the stress regime. If we are using the 'Basal Crevasse Model' (see SIF contents below), calving is predicted to occur where surface & basal crevasses meet. Otherwise, calving occurs where surface crevasses reach the waterline.
Calving location (x-coordinate) is computed, and then a vector defining the deformation of each node on the front is computed. In other words, displacing all the nodes on the front by the 'calving vector' produces the new calving front.
SIF Contents
Solver 15
Equation = Calving
Procedure = "ElmerIceSolvers" "Find_Calving"
Exec Solver = "After Timestep" !important
Basal Crevasse Model = Logical True !Look for surface crevasses meeting waterline
Old Way = Logical False
Yield Stress = Real 0.05 !MPa (usually...)
Basal FreeSurface = Logical True
Basal FreeSurface Variable Name = String "Zs Bottom"
! the crevasse water depth parameters
!Water Depth = Real $Dw
! Dw Start = Real $DwStart
! Dw Stop = Real $DwStop
! Dw Mode = String $DwMode
Variable = Calving
Variable DOFs = 2
Exported Variable 1 = -dofs 1 "Calving Surface Index"
Exported Variable 2 = -dofs 1 "Calving Basal Index"
Exported Variable 3 = -dofs 1 "Crevasse Group ID"
End
Solver Calving3D
Solver Fortran File: Calving3D.f90
Solver Name: Find_Calving3D
Required Output Variable(s):
Required Input Variable(s):
Optional Output Variable(s):
Optional Input Variable(s):
General Description
Information about the algorithm in this solver is provided here.
In addition to the main solver, Calving3D makes use of two auxiliary solvers which must be present in the SIF: Calving Isosurface, ProjectCalving.
SIF contents
Solver Options
Solver 19
Equation = "3D Calving"
Exec Solver = "After Timestep"
Procedure = "ElmerIceSolvers" "Find_Calving3D"
Solver Timing = Logical True
Variable = String "Calving"
Variable DOFs = 3
Exported Variable 1 = -dofs 1 "CIndex"
Exported Variable 1 DOFs = 1
Calving Search Distance = Real 3000.0
Calving Mesh Min LC = Real 30.0
Calving Mesh Max LC = Real 100.0
Calving Mesh LC Min Dist = Real 500.0
Calving Mesh LC Max Dist = Real 1500.0
Calving Append Name = String "$namerun"" !"
Calving Move Mesh Dir = String "./results/"
Project Calving Equation Name = String "CalvingProjection"
Isosurface Equation Name = String "Calving Isosurface"
Crevasse Penetration Threshold = Real 0.2 !this is the upper limit of average intact ice
Minimum Calving Event Size = Real 1.0 !minimum front displacement length
Pause Solvers Minimum Iceberg Volume = Real 1.0E6
Linear System Solver = Iterative
Linear System Iterative Method = BiCGStab
Linear System Max Iterations = 2000
Linear System Preconditioning = ILU1
Linear System Convergence Tolerance = 1.0e-9
Linear System Abort Not Converged = False
End
Solver 11
Equation = "CalvingProjection"
Procedure = File "ElmerIceSolvers" "ProjectCalving"
Exec Solver = "Never" !auxiliary solver called by Calving3D
Solver Timing = Logical True
Basal Crevasse Model = Logical True
Surface Crevasse Model = Logical True
Calving Stress Variable Name = String "Stress"
Plane Permutation(3) = Integer 1 3 2
Volume Permutation(3) = Integer 1 3 2
End
Solver 24
Exec Solver = "Never" !auxiliary solver called by Calving3D
Equation = "Calving Isosurface"
Procedure = File "Isosurface" "IsosurfaceSolver"
Isosurface Variable = String "ave_cindex"
Isosurface Value = Real 0.0
End
Examples
See [ELMER_TRUNK]/elmerice/Tests/Calving3D.
