Commit 2c0f2c9
Move ice-shelf basal friction to quadrature points
Previously, the nonlinear part of basal friction was evaluated
cell-wise, while the linear part was evaluated at quadrature points;
the resulting inconsistency in the Jacobian prevented quadratic
convergence when using Newton iterations, so moved all friction to be
evaluated evaluated at quadrature points instead. Viscosity should
also be evaluated at the 4 quad points rather than cell-centered, so
changed the default for NUMBER_OF_ICE_VISCOSITY_QUADRATURE_POINTS from
1 to 4 (which is more accurate anyway). These changes allow us to
achieve the expected quadratic convergence when using Newton.
With these changes, several deprecated cell-averaged ice-shelf CS
fields were removed: basal_traction, newton_umid, newton_vmid,
newton_drag_coef. Subroutine calc_shelf_taub was converted to return
area-averaged basal shear stress, now for diagnostic purposes only.
Also removed incorrect 0.5 factor from newton_visc_factor1 parent 56001bc commit 2c0f2c9
1 file changed
Lines changed: 547 additions & 381 deletions
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