mom_ice_shelf_dynamics module reference¶

mom_ice_shelf::solo_step_ice_shelf

function mom_ice_shelf_dynamics/ice_time_step_cfl(CS, ISS, G) [real]¶

This function returns the global maximum advective timestep that can be taken based on the current ice velocities. Because it involves finding a global minimum, it can be surprisingly expensive.

Parameters:

cs :: [inout] The ice shelf dynamics control structure
iss :: [inout] A structure with elements that describe the ice-shelf state
g :: [inout] The grid structure used by the ice shelf.

Return:

undefined :: The maximum permitted timestep based on the ice velocities [T ~> s].

Called from:

subroutine mom_ice_shelf_dynamics/update_ice_shelf(CS, ISS, G, US, time_step, Time, ocean_mass, coupled_grounding, must_update_vel)¶

This subroutine updates the ice shelf velocities, mass, stresses and properties due to the ice shelf dynamics.

Parameters:

cs :: [inout] The ice shelf dynamics control structure
iss :: [inout] A structure with elements that describe the ice-shelf state
g :: [inout] The grid structure used by the ice shelf.
us :: [in] A structure containing unit conversion factors
time_step :: [in] time step [T ~> s]
time :: [in] The current model time
ocean_mass :: [in] If present this is the mass per unit area
coupled_grounding :: [in] If true, the grounding line is determined by coupled ice-ocean dynamics
must_update_vel :: [in] Always update the ice velocities if true.

Call to:

mom_is_diag_mediator::disable_averaging mom_is_diag_mediator::enable_averages ice_shelf_advect ice_shelf_solve_outer update_od_ffrac update_od_ffrac_uncoupled

subroutine mom_ice_shelf_dynamics/write_ice_shelf_energy(CS, G, US, mass, day, time_step)¶

Writes the total ice shelf kinetic energy and mass to an ascii file.

Parameters:

cs :: [inout] The ice shelf dynamics control structure
g :: [inout] The grid structure used by the ice shelf.
us :: [in] A structure containing unit conversion factors
mass :: [in] The mass per unit area of the ice shelf
day :: [in] The current model time.
time_step :: [in] The current time step

subroutine mom_ice_shelf_dynamics/ice_shelf_advect(CS, ISS, G, time_step, Time)¶

This subroutine takes the velocity (on the Bgrid) and timesteps h_t = - div (uh) once. Additionally, it will update the volume of ice in partially-filled cells, and update hmask accordingly.

Parameters:

cs :: [inout] The ice shelf dynamics control structure
iss :: [inout] A structure with elements that describe the ice-shelf state
g :: [inout] The grid structure used by the ice shelf.
time_step :: [in] time step [T ~> s]
time :: [in] The current model time

Call to:

calve_to_mask ice_shelf_advect_thickness_x ice_shelf_advect_thickness_y ice_shelf_min_thickness_calve mom_error_handler::mom_error shelf_advance_front update_velocity_masks

Called from:

update_ice_shelf

subroutine mom_ice_shelf_dynamics/ice_shelf_solve_outer(CS, ISS, G, US, u_shlf, v_shlf, taudx, taudy, iters, Time)¶

This subroutine computes u- and v-velocities of the ice shelf iterating on non-linear ice viscosity.

Parameters:

cs :: [inout] The ice shelf dynamics control structure
iss :: [in] A structure with elements that describe the ice-shelf state
g :: [inout] The grid structure used by the ice shelf.
us :: [in] A structure containing unit conversion factors
u_shlf :: [inout] The zonal ice shelf velocity at vertices [L T-1 ~> m s-1]
v_shlf :: [inout] The meridional ice shelf velocity at vertices [L T-1 ~> m s-1]
iters :: [out] The number of iterations used in the solver.
time :: [in] The current model time
taudx :: [out] Driving x-stress at q-points [R L3 Z T-2 ~> kg m s-2]
taudy :: [out] Driving y-stress at q-points [R L3 Z T-2 ~> kg m s-2]

Call to:

calc_shelf_driving_stress calc_shelf_taub calc_shelf_visc cg_action ice_shelf_solve_inner interpolate_h_to_b mom_error_handler::mom_mesg

Called from:

initialize_diagnostic_fields update_ice_shelf

subroutine mom_ice_shelf_dynamics/ice_shelf_solve_inner(CS, ISS, G, US, u_shlf, v_shlf, taudx, taudy, H_node, float_cond, hmask, conv_flag, iters, time, Phi, Phisub)¶

Parameters:

cs :: [in] A pointer to the ice shelf control structure
iss :: [in] A structure with elements that describe the ice-shelf state
g :: [inout] The grid structure used by the ice shelf.
us :: [in] A structure containing unit conversion factors
u_shlf :: [inout] The zonal ice shelf velocity at vertices [L T-1 ~> m s-1]
v_shlf :: [inout] The meridional ice shelf velocity at vertices [L T-1 ~> m s-1]
taudx :: [in] The x-direction driving stress [R L3 Z T-2 ~> kg m s-2]
taudy :: [in] The y-direction driving stress [R L3 Z T-2 ~> kg m s-2]
h_node :: [in] The ice shelf thickness at nodal (corner)
float_cond :: [in] If GL_regularize=true, indicates cells containing
hmask :: [in] A mask indicating which tracer points are
conv_flag :: [out] A flag indicating whether (1) or not (0) the iterations have converged to the specified tolerance
iters :: [out] The number of iterations used in the solver.
time :: [in] The current model time
phi :: [in] The gradients of bilinear basis elements at Gaussian
phisub :: [in] Quadrature structure weights at subgridscale

Call to:

cg_action matrix_diagonal

Called from:

subroutine mom_ice_shelf_dynamics/ice_shelf_advect_thickness_x(CS, G, LB, time_step, hmask, h0, h_after_uflux, uh_ice)¶

Parameters:

cs :: [in] A pointer to the ice shelf control structure
g :: [in] The grid structure used by the ice shelf.
lb :: [in] Loop bounds structure.
time_step :: [in] The time step for this update [T ~> s].
hmask :: [inout] A mask indicating which tracer points are
h0 :: [in] The initial ice shelf thicknesses [Z ~> m].
h_after_uflux :: [inout] The ice shelf thicknesses after
uh_ice :: [inout] The accumulated zonal ice volume flux [Z L2 ~> m3]

Call to:

Called from:

subroutine mom_ice_shelf_dynamics/ice_shelf_advect_thickness_y(CS, G, LB, time_step, hmask, h0, h_after_vflux, vh_ice)¶

Parameters:

cs :: [in] A pointer to the ice shelf control structure
g :: [in] The grid structure used by the ice shelf.
lb :: [in] Loop bounds structure.
time_step :: [in] The time step for this update [T ~> s].
hmask :: [inout] A mask indicating which tracer points are
h0 :: [in] The initial ice shelf thicknesses [Z ~> m].
h_after_vflux :: [inout] The ice shelf thicknesses after
vh_ice :: [inout] The accumulated meridional ice volume flux [Z L2 ~> m3]

Call to:

Called from:

mom_error_handler::mom_mesg

subroutine mom_ice_shelf_dynamics/shelf_advance_front(CS, ISS, G, hmask, uh_ice, vh_ice)¶

Parameters:

cs :: [in] A pointer to the ice shelf control structure
iss :: [inout] A structure with elements that describe the ice-shelf state
g :: [in] The grid structure used by the ice shelf.
hmask :: [inout] A mask indicating which tracer points are
uh_ice :: [inout] The accumulated zonal ice volume flux [Z L2 ~> m3]
vh_ice :: [inout] The accumulated meridional ice volume flux [Z L2 ~> m3]

Call to:

Called from:

subroutine mom_ice_shelf_dynamics/ice_shelf_min_thickness_calve(G, h_shelf, area_shelf_h, hmask, thickness_calve, halo)¶

Apply a very simple calving law using a minimum thickness rule.

Parameters:

g :: [in] The grid structure used by the ice shelf.
h_shelf :: [inout] The ice shelf thickness [Z ~> m].
area_shelf_h :: [inout] The area per cell covered by the ice shelf [L2 ~> m2].
hmask :: [inout] A mask indicating which tracer points are partly or fully covered by an ice-shelf
thickness_calve :: [in] The thickness at which to trigger calving [Z ~> m].
halo :: [in] The number of halo points to use. If not present, work on the entire data domain.

Called from:

subroutine mom_ice_shelf_dynamics/calve_to_mask(G, h_shelf, area_shelf_h, hmask, calve_mask)¶

Parameters:

g :: [in] The grid structure used by the ice shelf.
h_shelf :: [inout] The ice shelf thickness [Z ~> m].
area_shelf_h :: [inout] The area per cell covered by the ice shelf [L2 ~> m2].
hmask :: [inout] A mask indicating which tracer points are partly or fully covered by an ice-shelf
calve_mask :: [in] A mask that indicates where the ice shelf can exist, and where it will calve.

Called from:

subroutine mom_ice_shelf_dynamics/calc_shelf_driving_stress(CS, ISS, G, US, taudx, taudy, OD)¶

Calculate driving stress using cell-centered bed elevation and ice thickness.

Parameters:

cs :: [in] A pointer to the ice shelf control structure
iss :: [in] A structure with elements that describe the ice-shelf state
g :: [inout] The grid structure used by the ice shelf.
us :: [in] A structure containing unit conversion factors
od :: [in] ocean floor depth at tracer points [Z ~> m].
taudx :: [inout] X-direction driving stress at q-points [R L3 Z T-2 ~> kg m s-2]
taudy :: [inout] Y-direction driving stress at q-points [R L3 Z T-2 ~> kg m s-2]

Called from:

cg_action_subgrid_basal

subroutine mom_ice_shelf_dynamics/init_boundary_values(CS, G, time, hmask, input_flux, input_thick, new_sim)¶

Parameters:

cs :: [inout] A pointer to the ice shelf control structure
g :: [inout] The grid structure used by the ice shelf.
time :: [in] The current model time
hmask :: [in] A mask indicating which tracer points are
input_flux :: [in] The integrated inward ice thickness flux per unit face length [Z L T-1 ~> m2 s-1]
input_thick :: [in] The ice thickness at boundaries [Z ~> m].
new_sim :: [in] If present and false, this run is being restarted

subroutine mom_ice_shelf_dynamics/cg_action(CS, uret, vret, u_shlf, v_shlf, Phi, Phisub, umask, vmask, hmask, H_node, ice_visc, float_cond, bathyT, basal_trac, G, US, is, ie, js, je, dens_ratio)¶

Parameters:

cs :: [in] A pointer to the ice shelf control structure
g :: [in] The grid structure used by the ice shelf.
uret :: [inout] The retarding stresses working at u-points [R L3 Z T-2 ~> kg m s-2].
vret :: [inout] The retarding stresses working at v-points [R L3 Z T-2 ~> kg m s-2].
phi :: [in] The gradients of bilinear basis elements at Gaussian
phisub :: [in] Quadrature structure weights at subgridscale
u_shlf :: [in] The zonal ice shelf velocity at vertices [L T-1 ~> m s-1]
v_shlf :: [in] The meridional ice shelf velocity at vertices [L T-1 ~> m s-1]
umask :: [in] A coded mask indicating the nature of the
vmask :: [in] A coded mask indicating the nature of the
h_node :: [in] The ice shelf thickness at nodal (corner)
hmask :: [in] A mask indicating which tracer points are
ice_visc :: [in] A field related to the ice viscosity from Glen’s
float_cond :: [in] If GL_regularize=true, an array indicating where the ice
bathyt :: [in] The depth of ocean bathymetry at tracer points
basal_trac :: [in] Area-integrated taub_beta field related to the nonlinear
dens_ratio :: [in] The density of ice divided by the density of seawater, nondimensional
us :: [in] A structure containing unit conversion factors
is :: [in] The starting i-index to work on
ie :: [in] The ending i-index to work on
js :: [in] The starting j-index to work on
je :: [in] The ending j-index to work on

Call to:

Called from:

ice_shelf_solve_inner ice_shelf_solve_outer

subroutine mom_ice_shelf_dynamics/cg_action_subgrid_basal(Phisub, H, U, V, bathyT, dens_ratio, Ucontr, Vcontr)¶

Parameters:

phisub :: [in] Quadrature structure weights at subgridscale
h :: [in] The ice shelf thickness at nodal (corner) points [Z ~> m].
u :: [in] The zonal ice shelf velocity at vertices [L T-1 ~> m s-1]
v :: [in] The meridional ice shelf velocity at vertices [L T-1 ~> m s-1]
bathyt :: [in] The depth of ocean bathymetry at tracer points relative to sea-level [Z ~> m].
dens_ratio :: [in] The density of ice divided by the density of seawater [nondim]
ucontr :: [out] The areal average of u-velocities where the ice shelf is grounded, or 0 where it is floating [L T-1 ~> m s-1].
vcontr :: [out] The areal average of v-velocities where the ice shelf is grounded, or 0 where it is floating [L T-1 ~> m s-1].

Call to:

sum_square_matrix

Called from:

cg_action

subroutine mom_ice_shelf_dynamics/sum_square_matrix(sum_out, mat_in, n)¶

Parameters:

n :: [in] The length and width of each matrix in mat_in
mat_in :: [in] The n x n matrix whose elements will be summed
sum_out :: [out] The sum of the elements of matrix mat_in

Called from:

cg_action_subgrid_basal cg_diagonal_subgrid_basal

subroutine mom_ice_shelf_dynamics/matrix_diagonal(CS, G, US, float_cond, H_node, ice_visc, basal_trac, hmask, dens_ratio, Phi, Phisub, u_diagonal, v_diagonal)¶

returns the diagonal entries of the matrix for a Jacobi preconditioning

Parameters:

cs :: [in] A pointer to the ice shelf control structure
g :: [in] The grid structure used by the ice shelf.
us :: [in] A structure containing unit conversion factors
float_cond :: [in] If GL_regularize=true, indicates cells containing
h_node :: [in] The ice shelf thickness at nodal
ice_visc :: [in] A field related to the ice viscosity from Glen’s
basal_trac :: [in] Area-integrated taub_beta field related to the nonlinear
hmask :: [in] A mask indicating which tracer points are
dens_ratio :: [in] The density of ice divided by the density of seawater [nondim]
phi :: [in] The gradients of bilinear basis elements at Gaussian
phisub :: [in] Quadrature structure weights at subgridscale locations for finite element calculations [nondim]
u_diagonal :: [inout] The diagonal elements of the u-velocity
v_diagonal :: [inout] The diagonal elements of the v-velocity

Call to:

cg_diagonal_subgrid_basal

Called from:

ice_shelf_solve_inner

subroutine mom_ice_shelf_dynamics/cg_diagonal_subgrid_basal(Phisub, H_node, bathyT, dens_ratio, f_grnd)¶

Parameters:

phisub :: [in] Quadrature structure weights at subgridscale
h_node :: [in] The ice shelf thickness at nodal (corner) points [Z ~> m].
bathyt :: [in] The depth of ocean bathymetry at tracer points [Z ~> m].
dens_ratio :: [in] The density of ice divided by the density of seawater [nondim]
f_grnd :: [out] The weighted fraction of the sub-cell where the ice shelf is grounded [nondim]

Call to:

sum_square_matrix

Called from:

matrix_diagonal

subroutine mom_ice_shelf_dynamics/calc_shelf_visc(CS, ISS, G, US, u_shlf, v_shlf)¶

Update depth integrated viscosity, based on horizontal strain rates.

Parameters:

cs :: [inout] A pointer to the ice shelf control structure
iss :: [in] A structure with elements that describe the ice-shelf state
g :: [in] The grid structure used by the ice shelf.
us :: [in] A structure containing unit conversion factors
u_shlf :: [inout] The zonal ice shelf velocity [L T-1 ~> m s-1].
v_shlf :: [inout] The meridional ice shelf velocity [L T-1 ~> m s-1].

Called from:

subroutine mom_ice_shelf_dynamics/calc_shelf_taub(CS, ISS, G, US, u_shlf, v_shlf)¶

Update basal shear.

Parameters:

cs :: [inout] A pointer to the ice shelf control structure
iss :: [in] A structure with elements that describe the ice-shelf state
g :: [in] The grid structure used by the ice shelf.
us :: [in] A structure containing unit conversion factors
u_shlf :: [inout] The zonal ice shelf velocity [L T-1 ~> m s-1].
v_shlf :: [inout] The meridional ice shelf velocity [L T-1 ~> m s-1].

Called from:

initialize_ice_shelf_dyn update_ice_shelf

subroutine mom_ice_shelf_dynamics/update_od_ffrac(CS, G, US, ocean_mass, find_avg)¶

Parameters:

cs :: [inout] A pointer to the ice shelf control structure
g :: [inout] The grid structure used by the ice shelf.
us :: [in] A structure containing unit conversion factors
ocean_mass :: [in] The mass per unit area of the ocean [R Z ~> kg m-2].
find_avg :: [in] If true, find the average of OD and ffrac, and reset the underlying running sums to 0.

Called from:

update_ice_shelf

subroutine mom_ice_shelf_dynamics/update_od_ffrac_uncoupled(CS, G, h_shelf)¶

Parameters:

cs :: [inout] A pointer to the ice shelf control structure
g :: [in] The grid structure used by the ice shelf.
h_shelf :: [in] the thickness of the ice shelf [Z ~> m].

Called from:

subroutine mom_ice_shelf_dynamics/change_in_draft(CS, G, h_shelf0, h_shelf1, ddraft)¶

Parameters:

cs :: [inout] A pointer to the ice shelf control structure
g :: [in] The grid structure used by the ice shelf.
h_shelf0 :: [in] the previous thickness of the ice shelf [Z ~> m].
h_shelf1 :: [in] the current thickness of the ice shelf [Z ~> m].
ddraft :: [inout] the change in shelf draft thickness

subroutine mom_ice_shelf_dynamics/bilinear_shape_functions(X, Y, Phi, area)¶

This subroutine calculates the gradients of bilinear basis elements that that are centered at the vertices of the cell. Values are calculated at points of gaussian quadrature.

Parameters:

x :: [in] The x-positions of the vertices of the quadrilateral [L ~> m].
y :: [in] The y-positions of the vertices of the quadrilateral [L ~> m].
phi :: [inout] The gradients of bilinear basis elements at Gaussian quadrature points surrounding the cell vertices [L-1 ~> m-1].
area :: [out] The quadrilateral cell area [L2 ~> m2].

Call to:

quad_area

subroutine mom_ice_shelf_dynamics/bilinear_shape_fn_grid(G, i, j, Phi)¶

This subroutine calculates the gradients of bilinear basis elements that are centered at the vertices of the cell using a locally orthogoal MOM6 grid. Values are calculated at points of gaussian quadrature.

Parameters:

g :: [in] The grid structure used by the ice shelf.
i :: [in] The i-index in the grid to work on.
j :: [in] The j-index in the grid to work on.
phi :: [inout] The gradients of bilinear basis elements at Gaussian quadrature points surrounding the cell vertices [L-1 ~> m-1].

Called from:

initialize_ice_shelf_dyn

subroutine mom_ice_shelf_dynamics/bilinear_shape_fn_grid_1qp(G, i, j, Phi)¶

This subroutine calculates the gradients of bilinear basis elements that are centered at the vertices of the cell using a locally orthogoal MOM6 grid. Values are calculated at a sinlge cell-centered quadrature point, which should match the grid cell h-point.

Parameters:

g :: [in] The grid structure used by the ice shelf.
i :: [in] The i-index in the grid to work on.
j :: [in] The j-index in the grid to work on.
phi :: [inout] The gradients of bilinear basis elements at Gaussian quadrature points surrounding the cell vertices [L-1 ~> m-1].

Called from:

initialize_ice_shelf_dyn

subroutine mom_ice_shelf_dynamics/bilinear_shape_functions_subgrid(Phisub, nsub)¶

Parameters:

nsub :: [in] The number of subgridscale quadrature locations in each direction
phisub :: [inout] Quadrature structure weights at subgridscale

Called from:

initialize_ice_shelf_dyn

subroutine mom_ice_shelf_dynamics/update_velocity_masks(CS, G, hmask, umask, vmask, u_face_mask, v_face_mask)¶

Parameters:

cs :: [in] A pointer to the ice shelf dynamics control structure
g :: [inout] The grid structure used by the ice shelf.
hmask :: [in] A mask indicating which tracer points are
umask :: [out] A coded mask indicating the nature of the
vmask :: [out] A coded mask indicating the nature of the
u_face_mask :: [out] A coded mask for velocities at the C-grid u-face
v_face_mask :: [out] A coded mask for velocities at the C-grid v-face

Called from:

ice_shelf_advect initialize_ice_shelf_dyn

subroutine mom_ice_shelf_dynamics/interpolate_h_to_b(G, h_shelf, hmask, H_node)¶

Interpolate the ice shelf thickness from tracer point to nodal points, subject to a mask.

Parameters:

g :: [inout] The grid structure used by the ice shelf.
h_shelf :: [in] The ice shelf thickness at tracer points [Z ~> m].
hmask :: [in] A mask indicating which tracer points are
h_node :: [inout] The ice shelf thickness at nodal (corner)

Called from:

ice_shelf_advect_temp_x ice_shelf_advect_temp_y

subroutine mom_ice_shelf_dynamics/ice_shelf_dyn_end(CS)¶

Deallocates all memory associated with the ice shelf dynamics module.

Parameters:: cs :: A pointer to the ice shelf dynamics control structure
Called from:: mom_ice_shelf::ice_shelf_end

subroutine mom_ice_shelf_dynamics/ice_shelf_temp(CS, ISS, G, US, time_step, melt_rate, Time)¶

This subroutine updates the vertically averaged ice shelf temperature.

Parameters:

cs :: [inout] A pointer to the ice shelf control structure
iss :: [in] A structure with elements that describe the ice-shelf state
g :: [inout] The grid structure used by the ice shelf.
us :: [in] A structure containing unit conversion factors
time_step :: [in] The time step for this update [T ~> s].
melt_rate :: [in] basal melt rate [R Z T-1 ~> kg m-2 s-1]
time :: [in] The current model time

Call to:

subroutine mom_ice_shelf_dynamics/ice_shelf_advect_temp_x(CS, G, time_step, hmask, h0, h_after_uflux)¶

Parameters:

cs :: [in] A pointer to the ice shelf control structure
g :: [inout] The grid structure used by the ice shelf.
time_step :: [in] The time step for this update [T ~> s].
hmask :: [in] A mask indicating which tracer points are
h0 :: [in] The initial ice shelf thicknesses times temperature [C Z ~> degC m]
h_after_uflux :: [inout] The ice shelf thicknesses times temperature after

Call to:

Called from:

ice_shelf_temp

subroutine mom_ice_shelf_dynamics/ice_shelf_advect_temp_y(CS, G, time_step, hmask, h_after_uflux, h_after_vflux)¶

Parameters:

cs :: [in] A pointer to the ice shelf control structure
g :: [in] The grid structure used by the ice shelf.
time_step :: [in] The time step for this update [T ~> s].
hmask :: [in] A mask indicating which tracer points are
h_after_uflux :: [in] The ice shelf thicknesses times temperature after
h_after_vflux :: [inout] The ice shelf thicknesses times temperature after

Call to: