+*Use thickness in ideal_age_tracer_column_physics

  Pass mixed layer thickness, rather than mixed layer depth, to
ideal_age_tracer_column_physics, and determine the number of layers within
the mixed layer in count_BL_layers in thickness units rather than depth units.
To accommodate these changes there is now a call to convert_MLD_to_ML_thickness
inside of call_tracer_column_fns.  The thermo_var_ptrs type argument (tv) to
ideal_age_tracer_column_physics and count_BL_layers are no longer used and
have been removed.  All answers are bitwise identical in Boussinesq mode, but
in non-Boussinesq mode there are changes in the passive ideal age tracers at
the level of roundoff.  There are also changes in the units of arguments and
the number of arguments to a public interface.

src/tracer/MOM_tracer_flow_control.F90

@@ -11,6 +11,7 @@ module MOM_tracer_flow_control
 use MOM_get_input,     only : Get_MOM_input
 use MOM_grid,          only : ocean_grid_type
 use MOM_hor_index,     only : hor_index_type
+use MOM_interface_heights, only : convert_MLD_to_ML_thickness
 use MOM_CVMix_KPP,     only : KPP_CS
 use MOM_open_boundary, only : ocean_OBC_type
 use MOM_restart,       only : MOM_restart_CS
@@ -427,7 +428,7 @@ subroutine call_tracer_set_forcing(sfc_state, fluxes, day_start, day_interval, G
 end subroutine call_tracer_set_forcing
 
 !> This subroutine calls all registered tracer column physics subroutines.
-subroutine call_tracer_column_fns(h_old, h_new, ea, eb, fluxes, Hml, dt, G, GV, US, tv, optics, CS, &
+subroutine call_tracer_column_fns(h_old, h_new, ea, eb, fluxes, mld, dt, G, GV, US, tv, optics, CS, &
                                   debug, KPP_CSp, nonLocalTrans, evap_CFL_limit, minimum_forcing_depth)
   type(ocean_grid_type),                 intent(in) :: G      !< The ocean's grid structure.
   type(verticalGrid_type),               intent(in) :: GV     !< The ocean's vertical grid structure.
@@ -444,7 +445,7 @@ subroutine call_tracer_column_fns(h_old, h_new, ea, eb, fluxes, Hml, dt, G, GV,
   type(forcing),                         intent(in) :: fluxes !< A structure containing pointers to
                                                               !! any possible forcing fields.
                                                               !! Unused fields have NULL ptrs.
-  real, dimension(SZI_(G),SZJ_(G)),      intent(in) :: Hml    !< Mixed layer depth [Z ~> m]
+  real, dimension(SZI_(G),SZJ_(G)),      intent(in) :: mld    !< Mixed layer depth [Z ~> m]
   real,                                  intent(in) :: dt     !< The amount of time covered by this
                                                               !! call [T ~> s]
   type(unit_scale_type),                 intent(in) :: US     !< A dimensional unit scaling type
@@ -464,6 +465,9 @@ subroutine call_tracer_column_fns(h_old, h_new, ea, eb, fluxes, Hml, dt, G, GV,
   real,                        optional, intent(in) :: minimum_forcing_depth !< The smallest depth over
                                                               !! which fluxes can be applied [H ~> m or kg m-2]
 
+  ! Local variables
+  real :: Hbl(SZI_(G),SZJ_(G))    !< Boundary layer thickness [H ~> m or kg m-2]
+
   if (.not. associated(CS)) call MOM_error(FATAL, "call_tracer_column_fns: "// &
          "Module must be initialized via call_tracer_register before it is used.")
 
@@ -488,12 +492,13 @@ subroutine call_tracer_column_fns(h_old, h_new, ea, eb, fluxes, Hml, dt, G, GV,
                                         G, GV, US, CS%RGC_tracer_CSp, &
                                         evap_CFL_limit=evap_CFL_limit, &
                                         minimum_forcing_depth=minimum_forcing_depth)
-    if (CS%use_ideal_age) &
+    if (CS%use_ideal_age) then
+      call convert_MLD_to_ML_thickness(mld, h_new, Hbl, tv, G, GV)
       call ideal_age_tracer_column_physics(h_old, h_new, ea, eb, fluxes, dt, &
-                                           G, GV, US, tv, CS%ideal_age_tracer_CSp, &
+                                           G, GV, US, CS%ideal_age_tracer_CSp, &
                                            evap_CFL_limit=evap_CFL_limit, &
-                                           minimum_forcing_depth=minimum_forcing_depth, &
-                                           Hbl=Hml)
+                                           minimum_forcing_depth=minimum_forcing_depth, Hbl=Hbl)
+    endif
     if (CS%use_regional_dyes) &
       call dye_tracer_column_physics(h_old, h_new, ea, eb, fluxes, dt, &
                                      G, GV, US, tv, CS%dye_tracer_CSp, &
@@ -526,7 +531,7 @@ subroutine call_tracer_column_fns(h_old, h_new, ea, eb, fluxes, Hml, dt, G, GV,
       if (US%QRZ_T_to_W_m2 /= 1.0) call MOM_error(FATAL, "MOM_generic_tracer_column_physics "//&
             "has not been written to permit dimensionsal rescaling.  Set all 4 of the "//&
             "[QRZT]_RESCALE_POWER parameters to 0.")
-      call MOM_generic_tracer_column_physics(h_old, h_new, ea, eb, fluxes, Hml, dt, &
+      call MOM_generic_tracer_column_physics(h_old, h_new, ea, eb, fluxes, mld, dt, &
                                              G, GV, US, CS%MOM_generic_tracer_CSp, tv, optics, &
                                              evap_CFL_limit=evap_CFL_limit, &
                                              minimum_forcing_depth=minimum_forcing_depth)
@@ -567,9 +572,11 @@ subroutine call_tracer_column_fns(h_old, h_new, ea, eb, fluxes, Hml, dt, G, GV,
     if (CS%use_RGC_tracer) &
       call RGC_tracer_column_physics(h_old, h_new, ea, eb, fluxes, dt, &
                                       G, GV, US, CS%RGC_tracer_CSp)
-    if (CS%use_ideal_age) &
+    if (CS%use_ideal_age) then
+      call convert_MLD_to_ML_thickness(mld, h_new, Hbl, tv, G, GV)
       call ideal_age_tracer_column_physics(h_old, h_new, ea, eb, fluxes, dt, &
-                                           G, GV, US, tv, CS%ideal_age_tracer_CSp, Hbl=Hml)
+                                           G, GV, US, CS%ideal_age_tracer_CSp, Hbl=Hbl)
+    endif
     if (CS%use_regional_dyes) &
       call dye_tracer_column_physics(h_old, h_new, ea, eb, fluxes, dt, &
                                            G, GV, US, tv, CS%dye_tracer_CSp)
@@ -591,7 +598,7 @@ subroutine call_tracer_column_fns(h_old, h_new, ea, eb, fluxes, Hml, dt, G, GV,
       if (US%QRZ_T_to_W_m2 /= 1.0) call MOM_error(FATAL, "MOM_generic_tracer_column_physics "//&
             "has not been written to permit dimensionsal rescaling.  Set all 4 of the "//&
             "[QRZT]_RESCALE_POWER parameters to 0.")
-      call MOM_generic_tracer_column_physics(h_old, h_new, ea, eb, fluxes, Hml, dt, &
+      call MOM_generic_tracer_column_physics(h_old, h_new, ea, eb, fluxes, mld, dt, &
                                      G, GV, US, CS%MOM_generic_tracer_CSp, tv, optics)
     endif
     if (CS%use_pseudo_salt_tracer) &

src/tracer/ideal_age_example.F90

@@ -12,7 +12,6 @@ module ideal_age_example
 use MOM_grid, only : ocean_grid_type
 use MOM_hor_index, only : hor_index_type
 use MOM_io, only : file_exists, MOM_read_data, slasher, vardesc, var_desc, query_vardesc
-use MOM_interface_heights, only : thickness_to_dz
 use MOM_open_boundary, only : ocean_OBC_type
 use MOM_restart, only : query_initialized, set_initialized, MOM_restart_CS
 use MOM_spatial_means, only : global_mass_int_EFP
@@ -22,7 +21,7 @@ module ideal_age_example
 use MOM_tracer_diabatic, only : tracer_vertdiff, applyTracerBoundaryFluxesInOut
 use MOM_tracer_Z_init, only : tracer_Z_init
 use MOM_unit_scaling, only : unit_scale_type
-use MOM_variables, only : surface, thermo_var_ptrs
+use MOM_variables, only : surface
 use MOM_verticalGrid, only : verticalGrid_type
 
 implicit none ; private
@@ -297,7 +296,7 @@ subroutine initialize_ideal_age_tracer(restart, day, G, GV, US, h, diag, OBC, CS
 end subroutine initialize_ideal_age_tracer
 
 !> Applies diapycnal diffusion, aging and regeneration at the surface to the ideal age tracers
-subroutine ideal_age_tracer_column_physics(h_old, h_new, ea, eb, fluxes, dt, G, GV, US, tv, CS, &
+subroutine ideal_age_tracer_column_physics(h_old, h_new, ea, eb, fluxes, dt, G, GV, US, CS, &
               evap_CFL_limit, minimum_forcing_depth, Hbl)
   type(ocean_grid_type),   intent(in) :: G    !< The ocean's grid structure
   type(verticalGrid_type), intent(in) :: GV   !< The ocean's vertical grid structure
@@ -317,14 +316,13 @@ subroutine ideal_age_tracer_column_physics(h_old, h_new, ea, eb, fluxes, dt, G,
                                               !! and tracer forcing fields.  Unused fields have NULL ptrs.
   real,                    intent(in) :: dt   !< The amount of time covered by this call [T ~> s]
   type(unit_scale_type),   intent(in) :: US   !< A dimensional unit scaling type
-  type(thermo_var_ptrs),   intent(in) :: tv   !< A structure pointing to various thermodynamic variables
   type(ideal_age_tracer_CS), pointer  :: CS   !< The control structure returned by a previous
                                               !! call to register_ideal_age_tracer.
   real,          optional, intent(in) :: evap_CFL_limit !< Limit on the fraction of the water that can
                                               !! be fluxed out of the top layer in a timestep [nondim]
   real,          optional, intent(in) :: minimum_forcing_depth !< The smallest depth over which
                                               !! fluxes can be applied [H ~> m or kg m-2]
-  real, dimension(SZI_(G),SZJ_(G)), optional, intent(in) :: Hbl !< Boundary layer depth [Z ~> m]
+  real, dimension(SZI_(G),SZJ_(G)), optional, intent(in) :: Hbl !< Boundary layer thickness [H ~> m or kg m-2]
 
 !   This subroutine applies diapycnal diffusion and any other column
 ! tracer physics or chemistry to the tracers from this file.
@@ -349,7 +347,7 @@ subroutine ideal_age_tracer_column_physics(h_old, h_new, ea, eb, fluxes, dt, G,
   endif
 
   if (CS%use_real_BL_depth .and. present(Hbl)) then
-    call count_BL_layers(G, GV, h_old, Hbl, tv, BL_layers)
+    call count_BL_layers(G, GV, h_old, Hbl, BL_layers)
   endif
 
   if (.not.associated(CS)) return
@@ -578,30 +576,27 @@ subroutine ideal_age_example_end(CS)
   endif
 end subroutine ideal_age_example_end
 
-subroutine count_BL_layers(G, GV, h, Hbl, tv, BL_layers)
-  type(ocean_grid_type),   intent(in) :: G    !< The ocean's grid structure
-  type(verticalGrid_type), intent(in) :: GV   !< The ocean's vertical grid structure
+subroutine count_BL_layers(G, GV, h, Hbl, BL_layers)
+  type(ocean_grid_type),            intent(in) :: G    !< The ocean's grid structure
+  type(verticalGrid_type),          intent(in) :: GV   !< The ocean's vertical grid structure
   real, dimension(SZI_(G),SZJ_(G),SZK_(GV)), &
-                           intent(in) :: h    !< Layer thicknesses [H ~> m or kg m-2].
-  real, dimension(SZI_(G),SZJ_(G)), intent(in) :: Hbl !< Boundary layer depth [Z ~> m]
-  type(thermo_var_ptrs),   intent(in) :: tv   !< A structure pointing to various thermodynamic variables
+                                    intent(in) :: h    !< Layer thicknesses [H ~> m or kg m-2].
+  real, dimension(SZI_(G),SZJ_(G)), intent(in) :: Hbl  !< Boundary layer thickness [H ~> m or kg m-2]
   real, dimension(SZI_(G),SZJ_(G)), intent(out) :: BL_layers !< Number of model layers in the boundary layer [nondim]
 
-  real :: dz(SZI_(G),SZK_(GV)) ! Height change across layers [Z ~> m]
-  real :: current_depth  ! Distance from the free surface [Z ~> m]
+  real :: current_depth  ! Distance from the free surface [H ~> m or kg m-2]
   integer :: i, j, k, is, ie, js, je, nz, m, nk
   character(len=255) :: msg
   is = G%isc ; ie = G%iec ; js = G%jsc ; je = G%jec ; nz = GV%ke
 
   BL_layers(:,:) = 0.
   do j=js,je
-    call thickness_to_dz(h, tv, dz, j, G, GV)
     do i=is,ie
       current_depth = 0.
       do k=1,nz
-        current_depth = current_depth + dz(i,k)
+        current_depth = current_depth + h(i,j,k)
         if (Hbl(i,j) <= current_depth) then
-          BL_layers(i,j) = BL_layers(i,j) + (1.0 - (current_depth - Hbl(i,j)) / dz(i,k))
+          BL_layers(i,j) = BL_layers(i,j) + (1.0 - (current_depth - Hbl(i,j)) / h(i,j,k))
           exit
         else
           BL_layers(i,j) = BL_layers(i,j) + 1.0