Merge branch 'dev/ncar' into merge_GME

NOAA-GFDL · May 17, 2019 · 03386c0 · 03386c0
2 parents eda43c4 + e0a8b9b
commit 03386c0
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Showing 2 changed files with 45 additions and 3 deletions.
diff --git a/config_src/nuopc_driver/MOM_surface_forcing.F90 b/config_src/nuopc_driver/MOM_surface_forcing.F90
@@ -1086,7 +1086,7 @@ subroutine surface_forcing_init(Time, G, US, param_file, diag, CS, restore_salt,
     call get_param(param_file, mdl, "USE_NET_FW_ADJUSTMENT_SIGN_BUG", &
                  CS%use_net_FW_adjustment_sign_bug, &
                    "If true, use the wrong sign for the adjustment to\n"//&
-                   "the net fresh-water.", default=.true.)
+                   "the net fresh-water.", default=.false.)
   call get_param(param_file, mdl, "ADJUST_NET_FRESH_WATER_BY_SCALING", &
                  CS%adjust_net_fresh_water_by_scaling, &
                  "If true, adjustments to net fresh water to achieve zero net are\n"//&

diff --git a/config_src/nuopc_driver/mom_cap.F90 b/config_src/nuopc_driver/mom_cap.F90
@@ -1764,6 +1764,7 @@ subroutine ModelAdvance(gcomp, rc)
   ! local variables
   integer                                :: userRc
   logical                                :: existflag, isPresent, isSet
+  logical                                :: do_advance = .true.
   type(ESMF_Clock)                       :: clock!< ESMF Clock class definition
   type(ESMF_Alarm)                       :: alarm
   type(ESMF_State)                       :: importState, exportState
@@ -1846,8 +1847,47 @@ subroutine ModelAdvance(gcomp, rc)
     file=__FILE__)) &
     return  ! bail out
 
-  Time = esmf2fms_time(currTime)
   Time_step_coupled = esmf2fms_time(timeStep)
+  Time = esmf2fms_time(currTime)
+
+  !---------------
+  ! Apply ocean lag for startup runs:
+  !---------------
+
+  if (cesm_coupled) then
+    if (trim(runtype) == "initial") then
+
+      ! Do not call MOM6 timestepping routine if the first cpl tstep of a startup run
+      if (currTime == startTime) then
+        call ESMF_LogWrite("MOM6 - Skipping the first coupling timestep", ESMF_LOGMSG_INFO, rc=rc)
+        if (ESMF_LogFoundError(rcToCheck=rc, msg=ESMF_LOGERR_PASSTHRU, &
+          line=__LINE__, &
+          file=__FILE__)) &
+          return  ! bail out
+        do_advance = .false.
+      else
+        do_advance = .true.
+      endif
+
+      ! If the second cpl tstep of a startup run, step back a cpl tstep and advance for two cpl tsteps
+      if (currTime == startTime + timeStep) then
+        call ESMF_LogWrite("MOM6 - Stepping back one coupling timestep", ESMF_LOGMSG_INFO, rc=rc)
+        if (ESMF_LogFoundError(rcToCheck=rc, msg=ESMF_LOGERR_PASSTHRU, &
+          line=__LINE__, &
+          file=__FILE__)) &
+          return  ! bail out
+        Time = esmf2fms_time(currTime-timeStep) ! i.e., startTime
+
+        call ESMF_LogWrite("MOM6 - doubling the coupling timestep", ESMF_LOGMSG_INFO, rc=rc)
+        if (ESMF_LogFoundError(rcToCheck=rc, msg=ESMF_LOGERR_PASSTHRU, &
+          line=__LINE__, &
+          file=__FILE__)) &
+          return  ! bail out
+        Time_step_coupled = 2 * esmf2fms_time(timeStep)
+      endif
+    endif
+  endif
+
 
   !---------------
   ! Write diagnostics for import
@@ -1890,7 +1930,9 @@ subroutine ModelAdvance(gcomp, rc)
   !---------------
 
   if(profile_memory) call ESMF_VMLogMemInfo("Entering MOM update_ocean_model: ")
-  call update_ocean_model(Ice_ocean_boundary, ocean_state, ocean_public, Time, Time_step_coupled)
+  if (do_advance) then
+    call update_ocean_model(Ice_ocean_boundary, ocean_state, ocean_public, Time, Time_step_coupled)
+  endif
   if(profile_memory) call ESMF_VMLogMemInfo("Leaving MOM update_ocean_model: ")
 
   !---------------