MohrCoulombYieldStress.cc File Reference

Process model which computes pseudo-plastic yield stress for the subglacial layer. More...

#include "pism/basalstrength/MohrCoulombYieldStress.hh"
#include "pism/basalstrength/MohrCoulombPointwise.hh"
#include "pism/util/Grid.hh"
#include "pism/util/Mask.hh"
#include "pism/util/error_handling.hh"
#include "pism/util/io/File.hh"
#include "pism/util/MaxTimestep.hh"
#include "pism/util/pism_utilities.hh"
#include "pism/util/Time.hh"
#include "pism/util/array/CellType.hh"
#include "pism/util/array/Forcing.hh"
#include "pism/geometry/Geometry.hh"
#include "pism/coupler/util/options.hh"

Go to the source code of this file.

Namespaces
	pism

Detailed Description

Process model which computes pseudo-plastic yield stress for the subglacial layer.

The output variable of this submodel is tauc, the pseudo-plastic yield stress field that is used in the ShallowStressBalance objects. This quantity is computed by the Mohr-Coulomb criterion [SchoofTill], but using an empirical relation between the amount of water in the till and the effective pressure of the overlying glacier resting on the till [Tulaczyketal2000].

The "dry" strength of the till is a state variable which is private to the submodel, namely tillphi. Its initialization is nontrivial: either the -topg_to_phi heuristic is used or inverse modeling can be used. (In the latter case tillphi can be read-in at the beginning of the run. Currently tillphi does not evolve during the run.)

The effective pressure is derived from the till (pore) water amount (the effective water layer thickness). Then the effective pressure is combined with tillphi to compute an updated tauc by the Mohr-Coulomb criterion.

This submodel is inactive in floating areas.

Definition in file MohrCoulombYieldStress.cc.