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+Add 2 runtime params for ice shelf temperatures
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  Added the new runtime parameters INFLOW_SHELF_TEMPERATURE and
MISSING_SHELF_TEMPERATURE to the ice_shelf_dynamics module to replace hard coded
ice shelf temperatures.  White space was also added around "=" in a number of
places in this same module to align with the MOM6 style guide.  By default, all
answers are bitwise identical, but there are new entries in some
MOM_parameter_doc files for cases that use the ice shelf code with
DYNAMIC_SHELF_MASS.
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@Hallberg-NOAA
Hallberg-NOAA committed Jan 2, 2023
1 parent 0bda74d commit 5573eb2
Showing 1 changed file with 56 additions and 43 deletions.
99 changes: 56 additions & 43 deletions src/ice_shelf/MOM_ice_shelf_dynamics.F90
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Original file line number Diff line number Diff line change
Expand Up @@ -147,7 +147,7 @@ module MOM_ice_shelf_dynamics
logical :: moving_shelf_front !< Specify whether to advance shelf front (and calve).
logical :: calve_to_mask !< If true, calve off the ice shelf when it passes the edge of a mask.
real :: min_thickness_simple_calve !< min. ice shelf thickness criteria for calving [Z ~> m].

real :: T_shelf_missing !< An ice shelf temperature to use where there is no ice shelf [degC ~> C]
real :: cg_tolerance !< The tolerance in the CG solver, relative to initial residual, that
!! determines when to stop the conjugate gradient iterations [nondim].
real :: nonlinear_tolerance !< The fractional nonlinear tolerance, relative to the initial error,
Expand Down Expand Up @@ -234,6 +234,8 @@ subroutine register_ice_shelf_dyn_restarts(G, US, param_file, CS, restart_CS)
type(ice_shelf_dyn_CS), pointer :: CS !< A pointer to the ice shelf dynamics control structure
type(MOM_restart_CS), intent(inout) :: restart_CS !< MOM restart control struct

! Local variables
real :: T_shelf_missing ! An ice shelf temperature to use where there is no ice shelf [degC ~> C]
logical :: shelf_mass_is_dynamic, override_shelf_movement, active_shelf_dynamics
character(len=40) :: mdl = "MOM_ice_shelf_dyn" ! This module's name.
integer :: isd, ied, jsd, jed, IsdB, IedB, JsdB, JedB
Expand All @@ -260,9 +262,12 @@ subroutine register_ice_shelf_dyn_restarts(G, US, param_file, CS, restart_CS)
endif

if (active_shelf_dynamics) then
call get_param(param_file, mdl, "MISSING_SHELF_TEMPERATURE", T_shelf_missing, &
"An ice shelf temperature to use where there is no ice shelf.",&
units="degC", default=-10.0, scale=US%degC_to_C, do_not_log=.true.)
allocate( CS%u_shelf(IsdB:IedB,JsdB:JedB), source=0.0 )
allocate( CS%v_shelf(IsdB:IedB,JsdB:JedB), source=0.0 )
allocate( CS%t_shelf(isd:ied,jsd:jed), source=-10.0*US%degC_to_C ) ! [C ~> degC]
allocate( CS%t_shelf(isd:ied,jsd:jed), source=T_shelf_missing ) ! [C ~> degC]
allocate( CS%ice_visc(isd:ied,jsd:jed), source=0.0 )
allocate( CS%AGlen_visc(isd:ied,jsd:jed), source=2.261e-25 ) ! [Pa-3 s-1]
allocate( CS%basal_traction(isd:ied,jsd:jed), source=0.0 ) ! [R L2 T-2 ~> Pa]
Expand Down Expand Up @@ -329,6 +334,8 @@ subroutine initialize_ice_shelf_dyn(param_file, Time, ISS, CS, G, US, diag, new_
! a restart file to the internal representation in this run.
real :: vel_rescale ! A rescaling factor for horizontal velocities from the representation
! in a restart file to the internal representation in this run.
real :: T_shelf_bdry ! A default ice shelf temperature to use for ice flowing
! in through open boundaries [C ~> degC]
!This include declares and sets the variable "version".
# include "version_variable.h"
character(len=200) :: IC_file,filename,inputdir
Expand Down Expand Up @@ -438,7 +445,13 @@ subroutine initialize_ice_shelf_dyn(param_file, Time, ISS, CS, G, US, diag, new_
"if CONSTANT a constant value (for debugging).", &
default="MODEL")

call get_param(param_file, mdl, "INFLOW_SHELF_TEMPERATURE", T_shelf_bdry, &
"A default ice shelf temperature to use for ice flowing in through "//&
"open boundaries.", units="degC", default=-15.0, scale=US%degC_to_C)
endif
call get_param(param_file, mdl, "MISSING_SHELF_TEMPERATURE", CS%T_shelf_missing, &
"An ice shelf temperature to use where there is no ice shelf.",&
units="degC", default=-10.0, scale=US%degC_to_C)
call get_param(param_file, mdl, "MIN_THICKNESS_SIMPLE_CALVE", CS%min_thickness_simple_calve, &
"Min thickness rule for the VERY simple calving law",&
units="m", default=0.0, scale=US%m_to_Z)
Expand All @@ -447,7 +460,7 @@ subroutine initialize_ice_shelf_dyn(param_file, Time, ISS, CS, G, US, diag, new_
! previously allocated for registration for restarts.

if (active_shelf_dynamics) then
allocate( CS%t_bdry_val(isd:ied,jsd:jed), source=-15.0*US%degC_to_C) ! [C ~> degC]
allocate( CS%t_bdry_val(isd:ied,jsd:jed), source=T_shelf_bdry) ! [C ~> degC]
allocate( CS%thickness_bdry_val(isd:ied,jsd:jed), source=0.0)
allocate( CS%u_face_mask(Isdq:Iedq,Jsdq:Jedq), source=0.0)
allocate( CS%v_face_mask(Isdq:Iedq,Jsdq:Jedq), source=0.0)
Expand Down Expand Up @@ -1415,7 +1428,7 @@ subroutine ice_shelf_advect_thickness_x(CS, G, LB, time_step, hmask, h0, h_after
do j=jsh,jeh ; do I=ish-1,ieh
if (CS%u_face_mask(I,j) == 4.) then ! The flux itself is a specified boundary condition.
uh_ice(I,j) = time_step * G%dyCu(I,j) * CS%u_flux_bdry_val(I,j)
elseif ((hmask(i,j)==1) .or. (hmask(i+1,j) == 1)) then
elseif ((hmask(i,j) == 1) .or. (hmask(i+1,j) == 1)) then
u_face = 0.5 * (CS%u_shelf(I,J-1) + CS%u_shelf(I,J))
h_face = 0.0 ! This will apply when the source cell is iceless or not fully ice covered.

Expand Down Expand Up @@ -1494,7 +1507,7 @@ subroutine ice_shelf_advect_thickness_y(CS, G, LB, time_step, hmask, h0, h_after
do J=jsh-1,jeh ; do i=ish,ieh
if (CS%v_face_mask(i,J) == 4.) then ! The flux itself is a specified boundary condition.
vh_ice(i,J) = time_step * G%dxCv(i,J) * CS%v_flux_bdry_val(i,J)
elseif ((hmask(i,j)==1) .or. (hmask(i,j+1) == 1)) then
elseif ((hmask(i,j) == 1) .or. (hmask(i,j+1) == 1)) then

v_face = 0.5 * (CS%v_shelf(I-1,J) + CS%v_shelf(I,J))
h_face = 0.0 ! This will apply when the source cell is iceless or not fully ice covered.
Expand Down Expand Up @@ -1854,7 +1867,7 @@ subroutine calc_shelf_driving_stress(CS, ISS, G, US, taudx, taudy, OD)
if (rhoi_rhow * ISS%h_shelf(i,j) - CS%bed_elev(i,j) <= 0) then
S(i,j) = (1 - rhoi_rhow)*ISS%h_shelf(i,j)
else
S(i,j)=ISS%h_shelf(i,j)-CS%bed_elev(i,j)
S(i,j) = ISS%h_shelf(i,j)-CS%bed_elev(i,j)
endif
enddo
enddo
Expand Down Expand Up @@ -2219,12 +2232,12 @@ subroutine CG_action(uret, vret, u_shlf, v_shlf, Phi, Phisub, umask, vmask, hmas
Hcell(:,:) = H_node(i-1:i,j-1:j)
call CG_action_subgrid_basal(Phisub, Hcell, Ucell, Vcell, bathyT(i,j), dens_ratio, Usub, Vsub)

if (umask(I-1,J-1)==1) uret(I-1,J-1) = uret(I-1,J-1) + Usub(1,1) * basal_trac(i,j)
if (umask(I-1,J-1) == 1) uret(I-1,J-1) = uret(I-1,J-1) + Usub(1,1) * basal_trac(i,j)
if (umask(I-1,J) == 1) uret(I-1,J) = uret(I-1,J) + Usub(1,2) * basal_trac(i,j)
if (umask(I,J-1) == 1) uret(I,J-1) = uret(I,J-1) + Usub(2,1) * basal_trac(i,j)
if (umask(I,J) == 1) uret(I,J) = uret(I,J) + Usub(2,2) * basal_trac(i,j)

if (vmask(I-1,J-1)==1) vret(I-1,J-1) = vret(I-1,J-1) + Vsub(1,1) * basal_trac(i,j)
if (vmask(I-1,J-1) == 1) vret(I-1,J-1) = vret(I-1,J-1) + Vsub(1,1) * basal_trac(i,j)
if (vmask(I-1,J) == 1) vret(I-1,J) = vret(I-1,J) + Vsub(1,2) * basal_trac(i,j)
if (vmask(I,J-1) == 1) vret(I,J-1) = vret(I,J-1) + Vsub(2,1) * basal_trac(i,j)
if (vmask(I,J) == 1) vret(I,J) = vret(I,J) + Vsub(2,2) * basal_trac(i,j)
Expand Down Expand Up @@ -2550,12 +2563,12 @@ subroutine apply_boundary_values(CS, ISS, G, US, time, Phisub, H_node, ice_visc,
call CG_action_subgrid_basal(Phisub, Hcell, Ucell, Vcell, CS%bed_elev(i,j), &
dens_ratio, Usubcontr, Vsubcontr)

if (CS%umask(I-1,J-1)==1) u_bdry_contr(I-1,J-1) = u_bdry_contr(I-1,J-1) + Usubcontr(1,1) * basal_trac(i,j)
if (CS%umask(I-1,J-1) == 1) u_bdry_contr(I-1,J-1) = u_bdry_contr(I-1,J-1) + Usubcontr(1,1) * basal_trac(i,j)
if (CS%umask(I-1,J) == 1) u_bdry_contr(I-1,J) = u_bdry_contr(I-1,J) + Usubcontr(1,2) * basal_trac(i,j)
if (CS%umask(I,J-1) == 1) u_bdry_contr(I,J-1) = u_bdry_contr(I,J-1) + Usubcontr(2,1) * basal_trac(i,j)
if (CS%umask(I,J) == 1) u_bdry_contr(I,J) = u_bdry_contr(I,J) + Usubcontr(2,2) * basal_trac(i,j)

if (CS%vmask(I-1,J-1)==1) v_bdry_contr(I-1,J-1) = v_bdry_contr(I-1,J-1) + Vsubcontr(1,1) * basal_trac(i,j)
if (CS%vmask(I-1,J-1) == 1) v_bdry_contr(I-1,J-1) = v_bdry_contr(I-1,J-1) + Vsubcontr(1,1) * basal_trac(i,j)
if (CS%vmask(I-1,J) == 1) v_bdry_contr(I-1,J) = v_bdry_contr(I-1,J) + Vsubcontr(1,2) * basal_trac(i,j)
if (CS%vmask(I,J-1) == 1) v_bdry_contr(I,J-1) = v_bdry_contr(I,J-1) + Vsubcontr(2,1) * basal_trac(i,j)
if (CS%vmask(I,J) == 1) v_bdry_contr(I,J) = v_bdry_contr(I,J) + Vsubcontr(2,2) * basal_trac(i,j)
Expand Down Expand Up @@ -2610,7 +2623,7 @@ subroutine calc_shelf_visc(CS, ISS, G, US, u_shlf, v_shlf)
enddo ; enddo

n_g = CS%n_glen; eps_min = CS%eps_glen_min
CS%ice_visc(:,:)=1e22
CS%ice_visc(:,:) = 1.0e22
! Visc_coef = US%kg_m2s_to_RZ_T*US%m_to_L*US%Z_to_L*(CS%A_glen_isothermal)**(-1./CS%n_glen)
do j=jsc,jec ; do i=isc,iec

Expand Down Expand Up @@ -2639,13 +2652,13 @@ subroutine calc_shelf_visc(CS, ISS, G, US, u_shlf, v_shlf)
(v_shlf(I-1,J) * Phi(6,2*(jq-1)+iq,i,j) + &
v_shlf(I,J-1) * Phi(4,2*(jq-1)+iq,i,j)) )
enddo ; enddo
if (trim(CS%ice_viscosity_compute)=="CONSTANT") then
if (trim(CS%ice_viscosity_compute) == "CONSTANT") then
CS%ice_visc(i,j) = 1e15 * US%kg_m3_to_R*US%m_to_L*US%m_s_to_L_T * (G%areaT(i,j) * ISS%h_shelf(i,j))
! constant viscocity for debugging
elseif (trim(CS%ice_viscosity_compute)=="MODEL") then
elseif (trim(CS%ice_viscosity_compute) == "MODEL") then
CS%ice_visc(i,j) = 0.5 * Visc_coef * (G%areaT(i,j) * ISS%h_shelf(i,j)) * &
(US%s_to_T**2 * (ux**2 + vy**2 + ux*vy + 0.25*(uy+vx)**2 + eps_min**2))**((1.-n_g)/(2.*n_g))
elseif (trim(CS%ice_viscosity_compute)=="OBS") then
elseif (trim(CS%ice_viscosity_compute) == "OBS") then
if (CS%AGlen_visc(i,j) >0) CS%ice_visc(i,j) = CS%AGlen_visc(i,j)*(G%areaT(i,j) * ISS%h_shelf(i,j))
! Here CS%Aglen_visc(i,j) is the ice viscocity [Pa s-1] computed from obs and read from a file
endif
Expand Down Expand Up @@ -3008,23 +3021,23 @@ subroutine update_velocity_masks(CS, G, hmask, umask, vmask, u_face_mask, v_face

select case (int(CS%u_face_mask_bdry(I-1+k,j)))
case (3)
vmask(I-1+k,J-1)=3.
u_face_mask(I-1+k,j)=3.
umask(I-1+k,J)=3.
vmask(I-1+k,J)=3.
vmask(I-1+k,J)=3.
vmask(I-1+k,J-1) = 3.
u_face_mask(I-1+k,j) = 3.
umask(I-1+k,J) = 3.
vmask(I-1+k,J) = 3.
vmask(I-1+k,J) = 3.
case (2)
u_face_mask(I-1+k,j)=2.
u_face_mask(I-1+k,j) = 2.
case (4)
umask(I-1+k,J-1:J)=0.
vmask(I-1+k,J-1:J)=0.
u_face_mask(I-1+k,j)=4.
umask(I-1+k,J-1:J) = 0.
vmask(I-1+k,J-1:J) = 0.
u_face_mask(I-1+k,j) = 4.
case (0)
umask(I-1+k,J-1:J)=0.
vmask(I-1+k,J-1:J)=0.
u_face_mask(I-1+k,j)=0.
umask(I-1+k,J-1:J) = 0.
vmask(I-1+k,J-1:J) = 0.
u_face_mask(I-1+k,j) = 0.
case (1) ! stress free x-boundary
umask(I-1+k,J-1:J)=0.
umask(I-1+k,J-1:J) = 0.
case default
end select
enddo
Expand All @@ -3033,23 +3046,23 @@ subroutine update_velocity_masks(CS, G, hmask, umask, vmask, u_face_mask, v_face

select case (int(CS%v_face_mask_bdry(i,J-1+k)))
case (3)
vmask(I-1,J-1+k)=3.
umask(I-1,J-1+k)=3.
vmask(I,J-1+k)=3.
umask(I,J-1+k)=3.
v_face_mask(i,J-1+k)=3.
vmask(I-1,J-1+k) = 3.
umask(I-1,J-1+k) = 3.
vmask(I,J-1+k) = 3.
umask(I,J-1+k) = 3.
v_face_mask(i,J-1+k) = 3.
case (2)
v_face_mask(i,J-1+k)=2.
v_face_mask(i,J-1+k) = 2.
case (4)
umask(I-1:I,J-1+k)=0.
vmask(I-1:I,J-1+k)=0.
v_face_mask(i,J-1+k)=4.
umask(I-1:I,J-1+k) = 0.
vmask(I-1:I,J-1+k) = 0.
v_face_mask(i,J-1+k) = 4.
case (0)
umask(I-1:I,J-1+k)=0.
vmask(I-1:I,J-1+k)=0.
v_face_mask(i,J-1+k)=0.
umask(I-1:I,J-1+k) = 0.
vmask(I-1:I,J-1+k) = 0.
v_face_mask(i,J-1+k) = 0.
case (1) ! stress free y-boundary
vmask(I-1:I,J-1+k)=0.
vmask(I-1:I,J-1+k) = 0.
case default
end select
enddo
Expand Down Expand Up @@ -3223,7 +3236,7 @@ subroutine ice_shelf_temp(CS, ISS, G, US, time_step, melt_rate, Time)
if (ISS%h_shelf(i,j) > 0.0) then
CS%t_shelf(i,j) = th_after_vflux(i,j) / ISS%h_shelf(i,j)
else
CS%t_shelf(i,j) = -10.0*US%degC_to_C
CS%t_shelf(i,j) = CS%T_shelf_missing
endif
! endif

Expand All @@ -3234,11 +3247,11 @@ subroutine ice_shelf_temp(CS, ISS, G, US, time_step, melt_rate, Time)
else
! the ice is about to melt away in this case set thickness, area, and mask to zero
! NOTE: not mass conservative, should maybe scale salt & heat flux for this cell
CS%t_shelf(i,j) = -10.0*US%degC_to_C
CS%t_shelf(i,j) = CS%T_shelf_missing
CS%tmask(i,j) = 0.0
endif
elseif (ISS%hmask(i,j) == 0) then
CS%t_shelf(i,j) = -10.0*US%degC_to_C
CS%t_shelf(i,j) = CS%T_shelf_missing
elseif ((ISS%hmask(i,j) == 3) .or. (ISS%hmask(i,j) == -2)) then
CS%t_shelf(i,j) = CS%t_bdry_val(i,j)
endif
Expand Down

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