Skip to content

Commit

Permalink
Calculate a photoacclimation mixed layer depth in MOM6 (NOAA-GFDL#16)
Browse files Browse the repository at this point in the history 
* Calculate a photoacclimation MLD in MOM6

Using the diagnose MLD routines calculate a MLD that can be used
in COBALTv3.

* Update interfaces for diagnoseMLD

Some previously optional arguments were made nonoptinal in the
final version merged into dev/gfdl. So these areguents have been
added to the call in MOM_generic_tracers.

* Add unset variable in diagnoseMLDbyenergy

* Remove timescale variable

This parameter seems unneeded at this time.

* Change paramter name and though up PR

Change "MLD_PHA_FIXED" to "MLD_PHA_CALC" which is default false.
Touch up a few formatting issues.
Add initialization and comment for mld_pha.

* Add fatal errors

Add fatal errors if PHA_MLD_CALC is true, but a method is not specified.

* Add additional argument to generic tracer stub

Add the photo_acc_mld argument to the generic tracer stub in MOM6.

---------

Co-authored-by: Theresa Morrison <Theresa.Morrison@gaea57.ncrc.gov>
Co-authored-by: Theresa Morrison <Theresa.Morrison@gaea56.ncrc.gov>
  • Loading branch information
@theresa-morrison
3 people authored and Theresa Morrison committed Nov 18, 2024
1 parent 69f4018 commit 0e9afb4
Show file tree
Hide file tree
Showing 3 changed files with 76 additions and 6 deletions.
3 changes: 2 additions & 1 deletion config_src/external/GFDL_ocean_BGC/generic_tracer.F90
View file
Original file line number Diff line number Diff line change
Expand Up @@ -70,7 +70,7 @@ end subroutine generic_tracer_coupler_accumulate
!> Calls the corresponding generic_X_update_from_source routine for each package X
subroutine generic_tracer_source(Temp,Salt,rho_dzt,dzt,hblt_depth,ilb,jlb,tau,dtts,&
grid_dat,model_time,nbands,max_wavelength_band,sw_pen_band,opacity_band,internal_heat,&
frunoff,grid_ht, current_wave_stress, sosga, geolat, eqn_of_state)
frunoff,grid_ht, current_wave_stress, sosga, geolat, eqn_of_state, photo_acc_dpth)
integer, intent(in) :: ilb !< Lower bounds of x extent of input arrays on data domain
integer, intent(in) :: jlb !< Lower bounds of y extent of input arrays on data domain
real, dimension(ilb:,jlb:,:), intent(in) :: Temp !< Potential temperature [deg C]
Expand Down Expand Up @@ -98,6 +98,7 @@ subroutine generic_tracer_source(Temp,Salt,rho_dzt,dzt,hblt_depth,ilb,jlb,tau,dt
real, optional , intent(in) :: sosga !< Global average sea surface salinity [ppt]
real, dimension(ilb:,jlb:),optional, intent(in) :: geolat !< Latitude
type(EOS_type), optional, intent(in) :: eqn_of_state !< A pointer to the equation of state
real, dimension(ilb:,jlb:), optional, intent(in) :: photo_acc_dpth
end subroutine generic_tracer_source

!> Update the tracers from bottom fluxes
Expand Down
12 changes: 10 additions & 2 deletions src/diagnostics/MOM_diagnose_MLD.F90
View file
Original file line number Diff line number Diff line change
Expand Up @@ -30,7 +30,7 @@ module MOM_diagnose_mld
!> Diagnose a mixed layer depth (MLD) determined by a given density difference with the surface.
!> This routine is appropriate in MOM_diabatic_aux due to its position within the time stepping.
subroutine diagnoseMLDbyDensityDifference(id_MLD, h, tv, densityDiff, G, GV, US, diagPtr, &
ref_h_mld, id_ref_z, id_ref_rho, id_N2subML, id_MLDsq, dz_subML)
ref_h_mld, id_ref_z, id_ref_rho, id_N2subML, id_MLDsq, dz_subML, MLD_out)
type(ocean_grid_type), intent(in) :: G !< Grid type
type(verticalGrid_type), intent(in) :: GV !< ocean vertical grid structure
type(unit_scale_type), intent(in) :: US !< A dimensional unit scaling type
Expand All @@ -44,6 +44,8 @@ subroutine diagnoseMLDbyDensityDifference(id_MLD, h, tv, densityDiff, G, GV, US,
real, intent(in) :: ref_h_mld !< Depth of the calculated "surface" densisty [Z ~> m]
integer, intent(in) :: id_ref_z !< Handle (ID) of reference depth diagnostic
integer, intent(in) :: id_ref_rho !< Handle (ID) of reference density diagnostic
real, dimension(SZI_(G),SZJ_(G)), &
optional, intent(inout) :: MLD_out !< Send MLD to other routines [Z ~> m]
integer, optional, intent(in) :: id_N2subML !< Optional handle (ID) of subML stratification
integer, optional, intent(in) :: id_MLDsq !< Optional handle (ID) of squared MLD
real, optional, intent(in) :: dz_subML !< The distance over which to calculate N2subML
Expand Down Expand Up @@ -234,11 +236,13 @@ subroutine diagnoseMLDbyDensityDifference(id_MLD, h, tv, densityDiff, G, GV, US,
if ((id_ref_z > 0) .and. (pRef_MLD(is)/=0.)) call post_data(id_ref_z, z_ref_diag , diagPtr)
if (id_ref_rho > 0) call post_data(id_ref_rho, rhoSurf_2d , diagPtr)

if (present(MLD_out)) MLD_out(:,:) = MLD(:,:)

end subroutine diagnoseMLDbyDensityDifference

!> Diagnose a mixed layer depth (MLD) determined by the depth a given energy value would mix.
!> This routine is appropriate in MOM_diabatic_aux due to its position within the time stepping.
subroutine diagnoseMLDbyEnergy(id_MLD, h, tv, G, GV, US, Mixing_Energy, diagPtr)
subroutine diagnoseMLDbyEnergy(id_MLD, h, tv, G, GV, US, Mixing_Energy, diagPtr, MLD_out)
! Author: Brandon Reichl
! Date: October 2, 2020
! //
Expand Down Expand Up @@ -270,6 +274,8 @@ subroutine diagnoseMLDbyEnergy(id_MLD, h, tv, G, GV, US, Mixing_Energy, diagPtr)
type(thermo_var_ptrs), intent(in) :: tv !< Structure containing pointers to any
!! available thermodynamic fields.
type(diag_ctrl), pointer :: diagPtr !< Diagnostics structure
real, dimension(SZI_(G),SZJ_(G)), &
optional, intent(inout) :: MLD_out !< Send MLD to other routines [Z ~> m]

! Local variables
real, dimension(SZI_(G),SZJ_(G),3) :: MLD ! Diagnosed mixed layer depth [Z ~> m].
Expand Down Expand Up @@ -467,6 +473,8 @@ subroutine diagnoseMLDbyEnergy(id_MLD, h, tv, G, GV, US, Mixing_Energy, diagPtr)
if (id_MLD(2) > 0) call post_data(id_MLD(2), MLD(:,:,2), diagPtr)
if (id_MLD(3) > 0) call post_data(id_MLD(3), MLD(:,:,3), diagPtr)

if (present(MLD_out)) MLD_out(:,:) = MLD(:,:,1)

end subroutine diagnoseMLDbyEnergy

!> \namespace mom_diagnose_mld
Expand Down
67 changes: 64 additions & 3 deletions src/tracer/MOM_generic_tracer.F90
View file
Original file line number Diff line number Diff line change
Expand Up @@ -32,6 +32,7 @@ module MOM_generic_tracer
use MOM_ALE_sponge, only : set_up_ALE_sponge_field, ALE_sponge_CS
use MOM_ALE_sponge, only : ALE_sponge_CS, initialize_ALE_sponge
use MOM_coms, only : EFP_type, max_across_PEs, min_across_PEs, PE_here
use MOM_diagnose_mld, only : diagnoseMLDbyDensityDifference, diagnoseMLDbyEnergy
use MOM_diag_mediator, only : post_data, register_diag_field, safe_alloc_ptr
use MOM_diag_mediator, only : diag_ctrl, get_diag_time_end
use MOM_error_handler, only : MOM_error, FATAL, WARNING, NOTE, is_root_pe
Expand Down Expand Up @@ -84,6 +85,14 @@ module MOM_generic_tracer
logical :: tracers_may_reinit !< If true, tracers may go through the
!! initialization code if they are not found in the restart files.

logical :: mld_pha_calc = .False. !< If true, use a fixed value for photoacclimation MLD
real :: mld_pha_val = 0.0 !< The value of fixed photoacclimation MLD
logical :: mld_pha_use_delta_rho = .False. !< If true, use a density diference to find the MLD
real :: mld_pha_href = 0.0 !< The reference depth for density difference based MLD
real :: mld_pha_drho = 0.03 !< The density thershold for a density difference based MLD
logical :: mld_pha_use_delta_eng = .False. !< If true, use an energy diference to find the MLD
real :: mld_pha_deng = 25.0 !< The energy threshold for an energy d ifference based MLD

type(diag_ctrl), pointer :: diag => NULL() !< A structure that is used to
!! regulate the timing of diagnostic output.
type(MOM_restart_CS), pointer :: restart_CSp => NULL() !< Restart control structure
Expand Down Expand Up @@ -425,6 +434,42 @@ subroutine initialize_MOM_generic_tracer(restart, day, G, GV, US, h, tv, param_f
enddo
!! end section to re-initialize generic tracers

call get_param(param_file, "MOM", "PHA_MLD_CALC", CS%mld_pha_calc, &
"If false, use a fixed value for the photoacclimation mixed layer depth within the "//&
"generic tracer update. This MLD is only used for photoacclimation. This variable should "//&
"be set to true if using COBALTv3 for the BGC.", default=.false.)
if (CS%mld_pha_calc) then
call get_param(param_file, "MOM", "PHA_MLD_USE_DELTA_RHO", CS%mld_pha_use_delta_rho, &
"If true, use a density difference to find the photoacclimation mixed layer depth "//&
"within the generic tracer update. This MLD is only used for photoacclimation.", default=.false.)
call get_param(param_file, "MOM", "PHA_MLD_USE_DELTA_ENG", CS%mld_pha_use_delta_eng, &
"If true, use an energy difference to find the photoacclimation mixed layer depth "//&
"with the generic tracer update. This MLD is only used for photoacclimation.", default=.false.)
if (CS%mld_pha_use_delta_rho .and. CS%mld_pha_use_delta_eng) then
call MOM_error(FATAL, "PHA_MLD_CALC is set to true and PHA_MLD_USE_DELTA_RHO and PHA_MLD_USE_DELTA_ENG "// &
"are both true. Choose only one option for the calculated photoacclimation MLD!")
elseif ((.not.CS%mld_pha_use_delta_rho) .and. (.not.CS%mld_pha_use_delta_eng)) then
call MOM_error(FATAL, "PHA_MLD_CALC is set to true but PHA_MLD_USE_DELTA_RHO and PHA_MLD_USE_DELTA_ENG "// &
"are both false. Choose an option for the calculated photoacclimation MLD!")
endif
if (CS%mld_pha_use_delta_rho) then
call get_param(param_file, "MOM", "PHA_MLD_HREF", CS%mld_pha_href, &
"The reference depth for a density difference based photoacclimation MLD [m].", &
units='m', default=0.0, scale=US%m_to_Z, do_not_log=.not.CS%mld_pha_use_delta_rho)
call get_param(param_file, "MOM", "PHA_MLD_DRHO", CS%mld_pha_drho, &
"The density difference for a density difference based photoacclimation MLD [kg m-3].", &
units='kg/m3', default=0.03, scale=US%kg_m3_to_R, do_not_log=.not.CS%mld_pha_use_delta_rho)
elseif (CS%mld_pha_use_delta_eng) then
call get_param(param_file, "MOM", "PHA_MLD_DENG", CS%mld_pha_deng, &
"The energy for an energy difference based photoacclimation MLD.", default=25.0, &
units='J/m2',scale=US%W_m2_to_RZ3_T3*US%s_to_T, do_not_log=.not.CS%mld_pha_use_delta_eng)
endif
else
call get_param(param_file, "MOM", "PHA_MLD_VAL", CS%mld_pha_val, &
"The depth of photoacclimation if fixed depth is used [m].", &
units='m', default=0.0, scale=US%m_to_Z)
endif


!Now we can reset the grid mask, axes and time to their true values
!Note that grid_tmask must be set correctly on the data domain boundary
Expand Down Expand Up @@ -654,6 +699,8 @@ subroutine MOM_generic_tracer_column_physics(h_old, h_new, ea, eb, fluxes, Hml,
real, dimension(SZI_(G),SZJ_(G),SZK_(GV)) :: rho_dzt ! Layer mass per unit area [kg m-2]
real, dimension(SZI_(G),SZJ_(G),SZK_(GV)) :: dzt ! Layer vertical extents [m]
real, dimension(SZI_(G),SZJ_(G),SZK_(GV)) :: h_work ! A work array of thicknesses [H ~> m or kg m-2]
real, dimension(SZI_(G),SZJ_(G)) :: mld_pha ! The mixed layer depth calculated for photoacclimation
! that is used in COBALTv3
integer :: i, j, k, isc, iec, jsc, jec, nk

isc = G%isc ; iec = G%iec ; jsc = G%jsc ; jec = G%jec ; nk = GV%ke
Expand Down Expand Up @@ -719,6 +766,17 @@ subroutine MOM_generic_tracer_column_physics(h_old, h_new, ea, eb, fluxes, Hml,
enddo ; enddo
sosga = global_area_mean(surface_field, G, unscale=US%S_to_ppt)

mld_pha(:,:) = 0.0
if (.not.CS%mld_pha_calc) then
mld_pha(:,:) = CS%mld_pha_val
else
if (CS%mld_pha_use_delta_rho) then
call diagnoseMLDbyDensityDifference(-1, h_old, tv, CS%mld_pha_drho, G, GV, US, CS%diag, CS%mld_pha_href, id_ref_z=-1, id_ref_rho=-1, MLD_out=mld_pha)
elseif (CS%mld_pha_use_delta_eng) then
call diagnoseMLDbyEnergy((/-1, -1, -1/), h_old, tv, G, GV, US, (/CS%mld_pha_deng, CS%mld_pha_deng, CS%mld_pha_deng/), CS%diag, MLD_out=mld_pha)
endif
endif

!
!Calculate tendencies (i.e., field changes at dt) from the sources / sinks
!
Expand All @@ -729,7 +787,8 @@ subroutine MOM_generic_tracer_column_physics(h_old, h_new, ea, eb, fluxes, Hml,
call generic_tracer_source(tv%T, tv%S, rho_dzt, dzt, dz_ml, G%isd, G%jsd, 1, dt, &
G%areaT, get_diag_time_end(CS%diag), &
optics%nbands, optics%max_wavelength_band, optics%sw_pen_band, optics%opacity_band, &
internal_heat=tv%internal_heat, frunoff=fluxes%frunoff, sosga=sosga, geolat=G%geolatT, eqn_of_state=tv%eqn_of_state)
internal_heat=tv%internal_heat, frunoff=fluxes%frunoff, sosga=sosga, geolat=G%geolatT, eqn_of_state=tv%eqn_of_state, &
photo_acc_dpth=mld_pha)
else
! tv%internal_heat is a null pointer unless DO_GEOTHERMAL = True,
! so we have to check and only do the scaling if it is associated.
Expand All @@ -740,14 +799,16 @@ subroutine MOM_generic_tracer_column_physics(h_old, h_new, ea, eb, fluxes, Hml,
sw_pen_band=G%US%QRZ_T_to_W_m2*optics%sw_pen_band(:,:,:), &
opacity_band=G%US%m_to_Z*optics%opacity_band(:,:,:,:), &
internal_heat=G%US%RZ_to_kg_m2*US%C_to_degC*tv%internal_heat(:,:), &
frunoff=G%US%RZ_T_to_kg_m2s*fluxes%frunoff(:,:), sosga=sosga, geolat=G%geolatT, eqn_of_state=tv%eqn_of_state)
frunoff=G%US%RZ_T_to_kg_m2s*fluxes%frunoff(:,:), sosga=sosga, geolat=G%geolatT, eqn_of_state=tv%eqn_of_state, &
photo_acc_dpth=mld_pha*US%Z_to_m)
else
call generic_tracer_source(US%C_to_degC*tv%T, US%S_to_ppt*tv%S, rho_dzt, dzt, dz_ml, G%isd, G%jsd, 1, dt, &
G%US%L_to_m**2*G%areaT(:,:), get_diag_time_end(CS%diag), &
optics%nbands, optics%max_wavelength_band, &
sw_pen_band=G%US%QRZ_T_to_W_m2*optics%sw_pen_band(:,:,:), &
opacity_band=G%US%m_to_Z*optics%opacity_band(:,:,:,:), &
frunoff=G%US%RZ_T_to_kg_m2s*fluxes%frunoff(:,:), sosga=sosga, geolat=G%geolatT, eqn_of_state=tv%eqn_of_state)
frunoff=G%US%RZ_T_to_kg_m2s*fluxes%frunoff(:,:), sosga=sosga, geolat=G%geolatT, eqn_of_state=tv%eqn_of_state, &
photo_acc_dpth=mld_pha*US%Z_to_m)
endif
endif

Expand Down

0 comments on commit 0e9afb4

Please sign in to comment.