Adds option to pass latent heat flux via IOB

Before, latent heat flux was computed by the ocean model using evap,lprec etc.
This PR adds the option to pass latent, computed by the coupler, to the ocean
via ice ocean boundary type (IOB). If IOB%latent has not been allocated, MOM6
will then compute latent heat flux as previously.

config_src/coupled_driver/MOM_surface_forcing.F90

@@ -152,6 +152,7 @@ module MOM_surface_forcing
   real, pointer, dimension(:,:) :: sw_flux_vis_dif      =>NULL() ! diffuse visible sw radiation (W/m2)
   real, pointer, dimension(:,:) :: sw_flux_nir_dir      =>NULL() ! direct Near InfraRed sw radiation (W/m2)
   real, pointer, dimension(:,:) :: sw_flux_nir_dif      =>NULL() ! diffuse Near InfraRed sw radiation (W/m2)
+  real, pointer, dimension(:,:) :: latent               =>NULL() ! latent heat flux (W/m2)
   real, pointer, dimension(:,:) :: lprec                =>NULL() ! mass flux of liquid precip (kg/m2/s)
   real, pointer, dimension(:,:) :: fprec                =>NULL() ! mass flux of frozen precip (kg/m2/s)
   real, pointer, dimension(:,:) :: runoff               =>NULL() ! mass flux of liquid runoff (kg/m2/s)
@@ -480,17 +481,21 @@ subroutine convert_IOB_to_fluxes(IOB, fluxes, index_bounds, Time, G, CS, state,
       fluxes%sens(i,j) = - IOB%t_flux(i-i0,j-j0) * G%mask2dT(i,j)
 
     fluxes%latent(i,j) = 0.0
-    if (ASSOCIATED(IOB%fprec)) then
-      fluxes%latent(i,j)            = fluxes%latent(i,j) - IOB%fprec(i-i0,j-j0)*CS%latent_heat_fusion
-      fluxes%latent_fprec_diag(i,j) = -G%mask2dT(i,j) * IOB%fprec(i-i0,j-j0)*CS%latent_heat_fusion
-    endif
-    if (ASSOCIATED(IOB%calving)) then
-      fluxes%latent(i,j)              = fluxes%latent(i,j) - IOB%calving(i-i0,j-j0)*CS%latent_heat_fusion
-      fluxes%latent_frunoff_diag(i,j) = -G%mask2dT(i,j) * IOB%calving(i-i0,j-j0)*CS%latent_heat_fusion
-    endif
-    if (ASSOCIATED(IOB%q_flux)) then
-      fluxes%latent(i,j)           = fluxes%latent(i,j) - IOB%q_flux(i-i0,j-j0)*CS%latent_heat_vapor
-      fluxes%latent_evap_diag(i,j) = -G%mask2dT(i,j) * IOB%q_flux(i-i0,j-j0)*CS%latent_heat_vapor
+    if (ASSOCIATED(IOB%latent)) then
+      fluxes%latent(i,j) = IOB%latent(i-i0,j-j0)
+    else
+      if (ASSOCIATED(IOB%fprec)) then
+        fluxes%latent(i,j)            = fluxes%latent(i,j) - IOB%fprec(i-i0,j-j0)*CS%latent_heat_fusion
+        fluxes%latent_fprec_diag(i,j) = -G%mask2dT(i,j) * IOB%fprec(i-i0,j-j0)*CS%latent_heat_fusion
+      endif
+      if (ASSOCIATED(IOB%calving)) then
+        fluxes%latent(i,j)              = fluxes%latent(i,j) - IOB%calving(i-i0,j-j0)*CS%latent_heat_fusion
+        fluxes%latent_frunoff_diag(i,j) = -G%mask2dT(i,j) * IOB%calving(i-i0,j-j0)*CS%latent_heat_fusion
+      endif
+      if (ASSOCIATED(IOB%q_flux)) then
+        fluxes%latent(i,j)           = fluxes%latent(i,j) - IOB%q_flux(i-i0,j-j0)*CS%latent_heat_vapor
+        fluxes%latent_evap_diag(i,j) = -G%mask2dT(i,j) * IOB%q_flux(i-i0,j-j0)*CS%latent_heat_vapor
+      endif
     endif
 
     fluxes%latent(i,j) = G%mask2dT(i,j) * fluxes%latent(i,j)

config_src/mct_driver/ocn_comp_mct.F90

@@ -558,6 +558,7 @@ subroutine ocn_init_mct( EClock, cdata_o, x2o_o, o2x_o, NLFilename )
   allocate(glb%ice_ocean_boundary%v_flux(isc:iec,jsc:jec));          glb%ice_ocean_boundary%v_flux(:,:) = 0.0
   allocate(glb%ice_ocean_boundary%t_flux(isc:iec,jsc:jec));          glb%ice_ocean_boundary%t_flux(:,:) = 0.0
   allocate(glb%ice_ocean_boundary%q_flux(isc:iec,jsc:jec));          glb%ice_ocean_boundary%q_flux(:,:) = 0.0
+  allocate(glb%ice_ocean_boundary%latent(isc:iec,jsc:jec));          glb%ice_ocean_boundary%latent(:,:) = 0.0
   allocate(glb%ice_ocean_boundary%salt_flux(isc:iec,jsc:jec));       glb%ice_ocean_boundary%salt_flux(:,:) = 0.0
   allocate(glb%ice_ocean_boundary%lw_flux(isc:iec,jsc:jec));         glb%ice_ocean_boundary%lw_flux(:,:) = 0.0
   allocate(glb%ice_ocean_boundary%sw_flux_vis_dir(isc:iec,jsc:jec)); glb%ice_ocean_boundary%sw_flux_vis_dir(:,:) = 0.0
@@ -1214,6 +1215,8 @@ subroutine fill_ice_ocean_bnd(ice_ocean_boundary, grid, x2o_o, ind, &
       ice_ocean_boundary%v_flux(ig,jg) = x2o_o(ind%x2o_Foxx_tauy,k)
       ! sensible heat flux (W/m2)
       ice_ocean_boundary%t_flux(ig,jg) = -x2o_o(ind%x2o_Foxx_sen,k)
+      ! latent heat flux (W/m^2)
+      ice_ocean_boundary%latent(ig,jg) = x2o_o(ind%x2o_Foxx_lat,k)
       ! salt flux
       ice_ocean_boundary%salt_flux(ig,jg) = -x2o_o(ind%x2o_Fioi_salt,k)
       ! heat content from frozen runoff