WIP: First attempt to add a generic tracer to OBC scheme

src/core/MOM.F90

@@ -259,6 +259,9 @@ module MOM
                                      !! calculated, and if it is 0, dtbt is calculated every step.
   type(time_type) :: dtbt_reset_interval !< A time_time representation of dtbt_reset_period.
   type(time_type) :: dtbt_reset_time !< The next time DTBT should be calculated.
+  real            :: update_OBC_period!< The time interval between OBC updates
+  type(time_type) :: update_OBC_interval !< A time_time representation of update_OBC_period.
+  type(time_type) :: update_OBC_time !< The next time OBC is applied.
 
 
   real, dimension(:,:,:), pointer :: &
@@ -1021,7 +1024,6 @@ subroutine step_MOM_dynamics(forces, p_surf_begin, p_surf_end, dt, dt_thermo, &
     call disable_averaging(CS%diag)
   endif
 
-
   if (CS%do_dynamics .and. CS%split) then !--------------------------- start SPLIT
     ! This section uses a split time stepping scheme for the dynamic equations,
     ! basically the stacked shallow water equations with viscosity.
@@ -1035,6 +1037,17 @@ subroutine step_MOM_dynamics(forces, p_surf_begin, p_surf_end, dt, dt_thermo, &
       endif
     endif
 
+    !OBC hack
+    if(associated(CS%OBC)) then
+     CS%OBC%update_OBC = .false.
+     if (CS%update_OBC_period == 0.0) CS%OBC%update_OBC = .true.
+     if (CS%update_OBC_period > 0.0) then
+      if (Time_local >= CS%update_OBC_time) then  !### Change >= to > here.
+       CS%OBC%update_OBC = .true.
+       CS%update_OBC_time = CS%update_OBC_time + CS%update_OBC_interval
+      endif
+     endif
+    endif
     call step_MOM_dyn_split_RK2(u, v, h, CS%tv, CS%visc, Time_local, dt, forces, &
                 p_surf_begin, p_surf_end, CS%uh, CS%vh, CS%uhtr, CS%vhtr, &
                 CS%eta_av_bc, G, GV, US, CS%dyn_split_RK2_CSp, calc_dtbt, CS%VarMix, &
@@ -1882,6 +1895,15 @@ subroutine initialize_MOM(Time, Time_init, param_file, dirs, CS, restart_CSp, &
                  "DTBT will be set every dynamics time step. The default "//&
                  "is set by DT_THERM.  This is only used if SPLIT is true.", &
                  units="s", default=default_val, do_not_read=(dtbt > 0.0))
+  !OBC hack
+    CS%update_OBC_period = -1.0
+    call get_param(param_file, "MOM", "UPDATE_OBC_PERIOD", CS%update_OBC_period, &
+                 "The period between recalculations OBC updates. "//&
+                 "If DTBT_RESET_PERIOD is negative, DTBT is set based "//&
+                 "only on information available at initialization.  If 0, "//&
+                 "OBC updates every dynamics time step. The default "//&
+                 "is set by DT_THERM.  This is only used if SPLIT is true.", &
+                 units="s", default=default_val, do_not_read=(dtbt > 0.0))
   endif
 
   ! This is here in case these values are used inappropriately.
@@ -2290,7 +2312,7 @@ subroutine initialize_MOM(Time, Time_init, param_file, dirs, CS, restart_CSp, &
   ! This subroutine calls user-specified tracer registration routines.
   ! Additional calls can be added to MOM_tracer_flow_control.F90.
   call call_tracer_register(dG%HI, GV, US, param_file, CS%tracer_flow_CSp, &
-                            CS%tracer_Reg, restart_CSp)
+                            CS%tracer_Reg, restart_CSp, CS%OBC)
 
   call MEKE_alloc_register_restart(dG%HI, param_file, CS%MEKE, restart_CSp)
   call set_visc_register_restarts(dG%HI, GV, param_file, CS%visc, restart_CSp)
@@ -2541,7 +2563,6 @@ subroutine initialize_MOM(Time, Time_init, param_file, dirs, CS, restart_CSp, &
   call VarMix_init(Time, G, GV, US, param_file, diag, CS%VarMix)
   call set_visc_init(Time, G, GV, US, param_file, diag, CS%visc, CS%set_visc_CSp, restart_CSp, CS%OBC)
   call thickness_diffuse_init(Time, G, GV, US, param_file, diag, CS%CDp, CS%thickness_diffuse_CSp)
-
   if (CS%split) then
     allocate(eta(SZI_(G),SZJ_(G))) ; eta(:,:) = 0.0
     call initialize_dyn_split_RK2(CS%u, CS%v, CS%h, CS%uh, CS%vh, eta, Time, &
@@ -2562,6 +2583,19 @@ subroutine initialize_MOM(Time, Time_init, param_file, dirs, CS, restart_CSp, &
         CS%dtbt_reset_time = CS%dtbt_reset_time - CS%dtbt_reset_interval
       endif
     endif
+    !OBC hack
+    if (associated(CS%OBC) .and. CS%update_OBC_period > 0.0) then
+      CS%update_OBC_interval = real_to_time(CS%update_OBC_period)
+      ! Set update_OBC_time to be the next even multiple of update_OBC_interval.
+      CS%update_OBC_time = Time_init + CS%update_OBC_interval * &
+                                 ((Time - Time_init) / CS%update_OBC_interval)
+      if ((CS%update_OBC_time > Time) .and. CS%OBC%update_OBC) then
+        ! Back up dtbt_reset_time one interval to force dtbt to be calculated,
+        ! because the restart was not aligned with the interval to recalculate
+        ! dtbt, and dtbt was not read from a restart file.
+        CS%update_OBC_time = CS%update_OBC_time - CS%update_OBC_interval
+      endif
+    endif
   elseif (CS%use_RK2) then
     call initialize_dyn_unsplit_RK2(CS%u, CS%v, CS%h, Time, G, GV, US,     &
             param_file, diag, CS%dyn_unsplit_RK2_CSp, restart_CSp,         &