+Revise the rescaled units of forces%tau_mag

  Revised the rescaled units of forces%tau_mag, fluxes%tau_mag and
fluxes%tau_mag_gustless from [R Z L T-2 ~> Pa] to [R Z2 T-2 ~> Pa] to avoid the
need for further rescaling when this field is used to calculate turbulent
friction velocities and TKE fluxes in 29 places.  However, this requires the
addition of other rescaling factors when forces%tau_mag is set from the wind
stresses.   A total of 40 rescaling factors were eliminated, while another
36 were added, all where the components of the wind stress are used to calculate
the magnitude of the wind stress.  Several other internal variables were also
rescaled analogously for simplicity.  All answers are bitwise identical, but
there are changes to the rescaling factors for three elements in a transparent
type.

Author: Hallberg-NOAA

config_src/drivers/FMS_cap/MOM_surface_forcing_gfdl.F90

@@ -85,14 +85,14 @@ module MOM_surface_forcing_gfdl
                                 !! type without any further adjustments to drive the ocean dynamics.
                                 !! The actual net mass source may differ due to corrections.
 
-  real :: gust_const            !< Constant unresolved background gustiness for ustar [R L Z T-2 ~> Pa]
+  real :: gust_const            !< Constant unresolved background gustiness for ustar [R Z2 T-2 ~> Pa]
   logical :: read_gust_2d       !< If true, use a 2-dimensional gustiness supplied from an input file.
   real, pointer, dimension(:,:) :: &
     BBL_tidal_dis => NULL()     !< Tidal energy dissipation in the bottom boundary layer that can act as a
                                 !! source of energy for bottom boundary layer mixing [R Z L2 T-3 ~> W m-2]
   real, pointer, dimension(:,:) :: &
     gust => NULL()              !< A spatially varying unresolved background gustiness that
-                                !! contributes to ustar [R L Z T-2 ~> Pa].  gust is used when read_gust_2d is true.
+                                !! contributes to ustar [R Z2 T-2 ~> Pa].  gust is used when read_gust_2d is true.
   real, pointer, dimension(:,:) :: &
     ustar_tidal => NULL()       !< Tidal contribution to the bottom friction velocity [Z T-1 ~> m s-1]
   real :: cd_tides              !< Drag coefficient that applies to the tides [nondim]
@@ -698,7 +698,7 @@ subroutine convert_IOB_to_forces(IOB, forces, index_bounds, Time, G, US, CS, dt_
     rigidity_at_h, &  ! Ice rigidity at tracer points [L4 Z-1 T-1 ~> m3 s-1]
     net_mass_src, &   ! A temporary of net mass sources [R Z T-1 ~> kg m-2 s-1].
     ustar_tmp, &      ! A temporary array of ustar values [Z T-1 ~> m s-1].
-    tau_mag_tmp       ! A temporary array of surface stress magnitudes [R Z L T-2 ~> Pa]
+    tau_mag_tmp       ! A temporary array of surface stress magnitudes [R Z2 T-2 ~> Pa]
 
   real :: I_GEarth      ! The inverse of the gravitational acceleration [T2 Z L-2 ~> s2 m-1]
   real :: Kv_rho_ice    ! (CS%Kv_sea_ice / CS%density_sea_ice) [L4 Z-2 T-1 R-1 ~> m5 s-1 kg-1]
@@ -939,10 +939,10 @@ subroutine extract_IOB_stresses(IOB, index_bounds, Time, G, US, CS, taux, tauy,
                                                  !! any contributions from gustiness [Z T-1 ~> m s-1].
   real, dimension(SZI_(G),SZJ_(G)), &
                  optional, intent(inout) :: mag_tau !< The magintude of the wind stress at tracer points
-                                                 !! including subgridscale variability and gustiness [R Z L T-2 ~> Pa]
+                                                 !! including subgridscale variability and gustiness [R Z2 T-2 ~> Pa]
   real, dimension(SZI_(G),SZJ_(G)), &
                  optional, intent(out) :: gustless_mag_tau !< The magintude of the wind stress at tracer points
-                                                 !! without any contributions from gustiness [R Z L T-2 ~> Pa]
+                                                 !! without any contributions from gustiness [R Z2 T-2 ~> Pa]
   integer,       optional, intent(in)    :: tau_halo !< The halo size of wind stresses to set, 0 by default.
 
   ! Local variables
@@ -953,11 +953,12 @@ subroutine extract_IOB_stresses(IOB, index_bounds, Time, G, US, CS, taux, tauy,
   real, dimension(SZIB_(G),SZJB_(G)) :: taux_in_B ! Zonal wind stresses [R Z L T-2 ~> Pa] at q points
   real, dimension(SZIB_(G),SZJB_(G)) :: tauy_in_B ! Meridional wind stresses [R Z L T-2 ~> Pa] at q points
 
-  real :: gustiness     ! unresolved gustiness that contributes to ustar [R Z L T-2 ~> Pa]
-  real :: Irho0         ! Inverse of the mean density rescaled to [Z L-1 R-1 ~> m3 kg-1]
+  real :: gustiness     ! unresolved gustiness that contributes to ustar [R Z2 T-2 ~> Pa]
+  real :: Irho0         ! Inverse of the Boussinesq mean density [R-1 ~> m3 kg-1]
   real :: taux2, tauy2  ! squared wind stresses [R2 Z2 L2 T-4 ~> Pa2]
-  real :: tau_mag       ! magnitude of the wind stress [R Z L T-2 ~> Pa]
+  real :: tau_mag       ! magnitude of the wind stress [R Z2 T-2 ~> Pa]
   real :: stress_conversion ! A unit conversion factor from Pa times any stress multiplier [R Z L T-2 Pa-1 ~> 1]
+  real :: Pa_to_RZ2_T2  ! The combination of unit conversion factors used for mag_tau [R Z2 T-2 Pa-1 ~> 1]
 
   logical :: do_ustar, do_gustless, do_tau_mag, do_gustless_tau_mag
   integer :: wind_stagger  ! AGRID, BGRID_NE, or CGRID_NE (integers from MOM_domains)
@@ -969,7 +970,7 @@ subroutine extract_IOB_stresses(IOB, index_bounds, Time, G, US, CS, taux, tauy,
   Isqh = G%IscB-halo ; Ieqh  = G%IecB+halo ; Jsqh = G%JscB-halo ; Jeqh = G%JecB+halo
   i0 = is - index_bounds(1) ; j0 = js - index_bounds(3)
 
-  IRho0 = US%L_to_Z / CS%Rho0
+  IRho0 = 1.0 / CS%Rho0
   stress_conversion = US%Pa_to_RLZ_T2 * CS%wind_stress_multiplier
 
   do_ustar = present(ustar) ; do_gustless = present(gustless_ustar)
@@ -1073,6 +1074,8 @@ subroutine extract_IOB_stresses(IOB, index_bounds, Time, G, US, CS, taux, tauy,
     ! parametizations. The background gustiness (for example with a relatively small value
     ! of 0.02 Pa) is intended to give reasonable behavior in regions of very weak winds.
     if (associated(IOB%stress_mag)) then
+      Pa_to_RZ2_T2 = US%Pa_to_RLZ_T2 * US%L_to_Z
+
       if (do_ustar .or. do_tau_mag) then ; do j=js,je ; do i=is,ie
         gustiness = CS%gust_const
         if (CS%read_gust_2d) then
@@ -1084,27 +1087,27 @@ subroutine extract_IOB_stresses(IOB, index_bounds, Time, G, US, CS, taux, tauy,
             gustiness = CS%gust(i,j)
         endif
         if (do_tau_mag) &
-          mag_tau(i,j) = gustiness + US%Pa_to_RLZ_T2*IOB%stress_mag(i-i0,j-j0)
+          mag_tau(i,j) = gustiness + Pa_to_RZ2_T2*IOB%stress_mag(i-i0,j-j0)
         if (do_gustless_tau_mag) &
-          gustless_mag_tau(i,j) = US%Pa_to_RLZ_T2*IOB%stress_mag(i-i0,j-j0)
+          gustless_mag_tau(i,j) = Pa_to_RZ2_T2*IOB%stress_mag(i-i0,j-j0)
         if (do_ustar) &
-          ustar(i,j) = sqrt(gustiness*IRho0 + IRho0*US%Pa_to_RLZ_T2*IOB%stress_mag(i-i0,j-j0))
+          ustar(i,j) = sqrt(gustiness*IRho0 + IRho0*Pa_to_RZ2_T2*IOB%stress_mag(i-i0,j-j0))
       enddo ; enddo ; endif
       if (CS%answer_date < 20190101) then
         if (do_gustless) then ; do j=js,je ; do i=is,ie
-          gustless_ustar(i,j) = sqrt(US%Pa_to_RLZ_T2*US%L_to_Z*IOB%stress_mag(i-i0,j-j0) / CS%Rho0)
+          gustless_ustar(i,j) = sqrt(Pa_to_RZ2_T2*IOB%stress_mag(i-i0,j-j0) / CS%Rho0)
         enddo ; enddo ; endif
       else
         if (do_gustless) then ; do j=js,je ; do i=is,ie
-          gustless_ustar(i,j) = sqrt(IRho0 * US%Pa_to_RLZ_T2*IOB%stress_mag(i-i0,j-j0))
+          gustless_ustar(i,j) = sqrt(IRho0 * Pa_to_RZ2_T2*IOB%stress_mag(i-i0,j-j0))
         enddo ; enddo ; endif
       endif
     elseif (wind_stagger == BGRID_NE) then
       do j=js,je ; do i=is,ie
         tau_mag = 0.0 ; gustiness = CS%gust_const
         if (((G%mask2dBu(I,J) + G%mask2dBu(I-1,J-1)) + &
              (G%mask2dBu(I,J-1) + G%mask2dBu(I-1,J))) > 0.0) then
-          tau_mag = sqrt(((G%mask2dBu(I,J)*((taux_in_B(I,J)**2) + (tauy_in_B(I,J)**2)) + &
+          tau_mag = US%L_to_Z * sqrt(((G%mask2dBu(I,J)*((taux_in_B(I,J)**2) + (tauy_in_B(I,J)**2)) + &
               G%mask2dBu(I-1,J-1)*((taux_in_B(I-1,J-1)**2) + (tauy_in_B(I-1,J-1)**2))) + &
              (G%mask2dBu(I,J-1)*((taux_in_B(I,J-1)**2) + (tauy_in_B(I,J-1)**2)) + &
               G%mask2dBu(I-1,J)*((taux_in_B(I-1,J)**2) + (tauy_in_B(I-1,J)**2))) ) / &
@@ -1115,21 +1118,21 @@ subroutine extract_IOB_stresses(IOB, index_bounds, Time, G, US, CS, taux, tauy,
         if (do_tau_mag) mag_tau(i,j) = gustiness + tau_mag
         if (do_gustless_tau_mag) gustless_mag_tau(i,j) = tau_mag
         if (CS%answer_date < 20190101) then
-          if (do_gustless) gustless_ustar(i,j) = sqrt(US%L_to_Z*tau_mag / CS%Rho0)
+          if (do_gustless) gustless_ustar(i,j) = sqrt(tau_mag / CS%Rho0)
         else
           if (do_gustless) gustless_ustar(i,j) = sqrt(IRho0 * tau_mag)
         endif
       enddo ; enddo
     elseif (wind_stagger == AGRID) then
       do j=js,je ; do i=is,ie
-        tau_mag = G%mask2dT(i,j) * sqrt((taux_in_A(i,j)**2) + (tauy_in_A(i,j)**2))
+        tau_mag = G%mask2dT(i,j) * US%L_to_Z * sqrt((taux_in_A(i,j)**2) + (tauy_in_A(i,j)**2))
         gustiness = CS%gust_const
         if (CS%read_gust_2d .and. (G%mask2dT(i,j) > 0.0)) gustiness = CS%gust(i,j)
         if (do_ustar) ustar(i,j) = sqrt(gustiness*IRho0 + IRho0 * tau_mag)
         if (do_tau_mag) mag_tau(i,j) = gustiness + tau_mag
         if (do_gustless_tau_mag) gustless_mag_tau(i,j) = tau_mag
         if (CS%answer_date < 20190101) then
-          if (do_gustless) gustless_ustar(i,j) = sqrt(US%L_to_Z*tau_mag / CS%Rho0)
+          if (do_gustless) gustless_ustar(i,j) = sqrt(tau_mag / CS%Rho0)
         else
           if (do_gustless) gustless_ustar(i,j) = sqrt(IRho0 * tau_mag)
         endif
@@ -1143,7 +1146,7 @@ subroutine extract_IOB_stresses(IOB, index_bounds, Time, G, US, CS, taux, tauy,
         if ((G%mask2dCv(i,J-1) + G%mask2dCv(i,J)) > 0.0) &
           tauy2 = (G%mask2dCv(i,J-1)*(tauy_in_C(i,J-1)**2) + G%mask2dCv(i,J)*(tauy_in_C(i,J)**2)) / &
                   (G%mask2dCv(i,J-1) + G%mask2dCv(i,J))
-        tau_mag = sqrt(taux2 + tauy2)
+        tau_mag = US%L_to_Z * sqrt(taux2 + tauy2)
 
         gustiness = CS%gust_const
         if (CS%read_gust_2d) gustiness = CS%gust(i,j)
@@ -1152,7 +1155,7 @@ subroutine extract_IOB_stresses(IOB, index_bounds, Time, G, US, CS, taux, tauy,
         if (do_tau_mag) mag_tau(i,j) = gustiness + tau_mag
         if (do_gustless_tau_mag) gustless_mag_tau(i,j) = tau_mag
         if (CS%answer_date < 20190101) then
-          if (do_gustless) gustless_ustar(i,j) = sqrt(US%L_to_Z*tau_mag / CS%Rho0)
+          if (do_gustless) gustless_ustar(i,j) = sqrt(tau_mag / CS%Rho0)
         else
           if (do_gustless) gustless_ustar(i,j) = sqrt(IRho0 * tau_mag)
         endif
@@ -1616,7 +1619,7 @@ subroutine surface_forcing_init(Time, G, US, param_file, diag, CS, wind_stagger)
                  "an input file", default=.false.)
   call get_param(param_file, mdl, "GUST_CONST", CS%gust_const, &
                  "The background gustiness in the winds.", &
-                 units="Pa", default=0.0, scale=US%Pa_to_RLZ_T2)
+                 units="Pa", default=0.0, scale=US%Pa_to_RLZ_T2*US%L_to_Z)
   if (CS%read_gust_2d) then
     call get_param(param_file, mdl, "GUST_2D_FILE", gust_file, &
                  "The file in which the wind gustiness is found in "//&
@@ -1627,7 +1630,7 @@ subroutine surface_forcing_init(Time, G, US, param_file, diag, CS, wind_stagger)
     ! NOTE: There are certain cases where FMS is unable to read this file, so
     ! we use read_netCDF_data in place of MOM_read_data.
     call read_netCDF_data(gust_file, 'gustiness', CS%gust, G%Domain, &
-                          rescale=US%Pa_to_RLZ_T2) ! units in file should be [Pa]
+                          rescale=US%Pa_to_RLZ_T2*US%L_to_Z) ! units in file should be [Pa]
   endif
   call get_param(param_file, mdl, "DEFAULT_ANSWER_DATE", default_answer_date, &
                  "This sets the default value for the various _ANSWER_DATE parameters.", &

config_src/drivers/FMS_cap/ocean_model_MOM.F90

@@ -32,7 +32,6 @@ module ocean_model_mod
 use MOM_file_parser, only : get_param, log_version, close_param_file, param_file_type
 use MOM_forcing_type, only : forcing, mech_forcing, allocate_forcing_type
 use MOM_forcing_type, only : fluxes_accumulate, get_net_mass_forcing
-use MOM_forcing_type, only : copy_back_forcing_fields
 use MOM_forcing_type, only : forcing_diagnostics, mech_forcing_diags
 use MOM_get_input, only : Get_MOM_Input, directories
 use MOM_grid, only : ocean_grid_type

config_src/drivers/STALE_mct_cap/mom_surface_forcing_mct.F90

@@ -774,7 +774,7 @@ subroutine convert_IOB_to_forces(IOB, forces, index_bounds, Time, G, US, CS)
              ((G%mask2dBu(I,J) + G%mask2dBu(I-1,J-1)) + (G%mask2dBu(I,J-1) + G%mask2dBu(I-1,J))) )
         if (CS%read_gust_2d) gustiness = CS%gust(i,j)
       endif
-      forces%tau_mag(i,j) = gustiness + tau_mag
+      forces%tau_mag(i,j) = US%L_to_Z*(gustiness + tau_mag)
       forces%ustar(i,j) = sqrt(gustiness*Irho0 + Irho0*tau_mag)
     enddo ; enddo
 
@@ -800,7 +800,7 @@ subroutine convert_IOB_to_forces(IOB, forces, index_bounds, Time, G, US, CS)
     do j=js,je ; do i=is,ie
       gustiness = CS%gust_const
       if (CS%read_gust_2d .and. (G%mask2dT(i,j) > 0.0)) gustiness = CS%gust(i,j)
-      forces%tau_mag(i,j) = gustiness + G%mask2dT(i,j) * sqrt((taux_at_h(i,j)**2) + (tauy_at_h(i,j)**2))
+      forces%tau_mag(i,j) = US%L_to_Z*(gustiness + G%mask2dT(i,j) * sqrt((taux_at_h(i,j)**2) + (tauy_at_h(i,j)**2)))
       forces%ustar(i,j) = sqrt(gustiness*Irho0 + Irho0 * G%mask2dT(i,j) * &
                                sqrt((taux_at_h(i,j)**2) + (tauy_at_h(i,j)**2)))
     enddo ; enddo
@@ -822,10 +822,10 @@ subroutine convert_IOB_to_forces(IOB, forces, index_bounds, Time, G, US, CS)
                  G%mask2dCv(i,J)*(forces%tauy(i,J)**2)) / (G%mask2dCv(i,J-1) + G%mask2dCv(i,J))
 
       if (CS%read_gust_2d) then
-        forces%tau_mag(i,j) = CS%gust(i,j) + sqrt(taux2 + tauy2)
+        forces%tau_mag(i,j) = US%L_to_Z*(CS%gust(i,j) + sqrt(taux2 + tauy2))
         forces%ustar(i,j) = sqrt(CS%gust(i,j)*Irho0 + Irho0*sqrt(taux2 + tauy2))
       else
-        forces%tau_mag(i,j) = CS%gust_const + sqrt(taux2 + tauy2)
+        forces%tau_mag(i,j) = US%L_to_Z*(CS%gust_const + sqrt(taux2 + tauy2))
         forces%ustar(i,j) = sqrt(CS%gust_const*Irho0 + Irho0*sqrt(taux2 + tauy2))
       endif
     enddo ; enddo

config_src/drivers/nuopc_cap/mom_surface_forcing_nuopc.F90

@@ -835,7 +835,7 @@ subroutine convert_IOB_to_forces(IOB, forces, index_bounds, Time, G, US, CS)
           ((G%mask2dBu(I,J) + G%mask2dBu(I-1,J-1)) + (G%mask2dBu(I,J-1) + G%mask2dBu(I-1,J))) )
         if (CS%read_gust_2d) gustiness = CS%gust(i,j)
       endif
-      forces%tau_mag(i,j) = gustiness + tau_mag
+      forces%tau_mag(i,j) = US%L_to_Z*(gustiness + tau_mag)
       forces%ustar(i,j) = sqrt(gustiness*Irho0 + Irho0*tau_mag)
     enddo ; enddo
     call pass_vector(forces%taux, forces%tauy, G%Domain, halo=1)
@@ -861,7 +861,7 @@ subroutine convert_IOB_to_forces(IOB, forces, index_bounds, Time, G, US, CS)
     do j=js,je ; do i=is,ie
       gustiness = CS%gust_const
       if (CS%read_gust_2d .and. (G%mask2dT(i,j) > 0.0)) gustiness = CS%gust(i,j)
-      forces%tau_mag(i,j) = gustiness + G%mask2dT(i,j) * sqrt((taux_at_h(i,j)**2) + (tauy_at_h(i,j)**2))
+      forces%tau_mag(i,j) = US%L_to_Z*(gustiness + G%mask2dT(i,j) * sqrt((taux_at_h(i,j)**2) + (tauy_at_h(i,j)**2)))
       forces%ustar(i,j) = sqrt(gustiness*Irho0 + Irho0 * G%mask2dT(i,j) * &
                                sqrt((taux_at_h(i,j)**2) + (tauy_at_h(i,j)**2)))
       !forces%omega_w2x(i,j) = atan(tauy_at_h(i,j), taux_at_h(i,j))
@@ -884,10 +884,10 @@ subroutine convert_IOB_to_forces(IOB, forces, index_bounds, Time, G, US, CS)
                  G%mask2dCv(i,J)*(forces%tauy(i,J)**2)) / (G%mask2dCv(i,J-1) + G%mask2dCv(i,J))
 
       if (CS%read_gust_2d) then
-        forces%tau_mag(i,j) = CS%gust(i,j) + sqrt(taux2 + tauy2)
+        forces%tau_mag(i,j) = US%L_to_Z*(CS%gust(i,j) + sqrt(taux2 + tauy2))
         forces%ustar(i,j) = sqrt(CS%gust(i,j)*Irho0 + Irho0*sqrt(taux2 + tauy2))
       else
-        forces%tau_mag(i,j) = CS%gust_const + sqrt(taux2 + tauy2)
+        forces%tau_mag(i,j) = US%L_to_Z*(CS%gust_const + sqrt(taux2 + tauy2))
         forces%ustar(i,j) = sqrt(CS%gust_const*Irho0 + Irho0*sqrt(taux2 + tauy2))
       endif
     enddo ; enddo