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Rescaled ice_shelf_CS%g_Earth like GV%g_Earth
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  Revised the dimensional rescaling of ice_shelf_CS%g_Earth to match GV%g_Earth
and ice_shelf_dyn_CS%g_Earth to minimize confusion when examining different parts
of the code.  Also cancelled out pairs of unit conversion factors when setting
the ice shelf contributions to fluxes%p_surf and forces%p_surf.  All answers are
bitwise identical.
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@Hallberg-NOAA
Hallberg-NOAA committed Apr 8, 2020
1 parent 20ae74d commit 916be3c
Showing 1 changed file with 13 additions and 16 deletions.
29 changes: 13 additions & 16 deletions src/ice_shelf/MOM_ice_shelf.F90
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Original file line number Diff line number Diff line change
Expand Up @@ -92,7 +92,7 @@ module MOM_ice_shelf

real :: ustar_bg !< A minimum value for ustar under ice shelves [Z T-1 ~> m s-1].
real :: cdrag !< drag coefficient under ice shelves [nondim].
real :: g_Earth !< The gravitational acceleration [Z T-2 ~> m s-2]
real :: g_Earth !< The gravitational acceleration [L2 Z-1 T-2 ~> m s-2]
real :: Cp !< The heat capacity of sea water [Q degC-1 ~> J kg-1 degC-1].
real :: Rho_ocn !< A reference ocean density [R ~> kg m-3].
real :: Cp_ice !< The heat capacity of fresh ice [Q degC-1 ~> J kg-1 degC-1].
Expand Down Expand Up @@ -371,7 +371,7 @@ subroutine shelf_calc_flux(state, fluxes, Time, time_step, CS, forces)
do j=js,je
! Find the pressure at the ice-ocean interface, averaged only over the
! part of the cell covered by ice shelf.
do i=is,ie ; p_int(i) = US%RZ_to_kg_m2*US%Z_to_m*US%s_to_T**2*CS%g_Earth * ISS%mass_shelf(i,j) ; enddo
do i=is,ie ; p_int(i) = US%RL2_T2_to_Pa*CS%g_Earth * ISS%mass_shelf(i,j) ; enddo

! Calculate insitu densities and expansion coefficients
call calculate_density(state%sst(:,j), state%sss(:,j), p_int, &
Expand Down Expand Up @@ -399,8 +399,8 @@ subroutine shelf_calc_flux(state, fluxes, Time, time_step, CS, forces)
hBL_neut_h_molec = ZETA_N * ((hBL_neut * ustar_h) / (5.0 * CS%kv_molec))

! Determine the mixed layer buoyancy flux, wB_flux.
dB_dS = (CS%g_Earth / Rhoml(i)) * dR0_dS(i)
dB_dT = (CS%g_Earth / Rhoml(i)) * dR0_dT(i)
dB_dS = (US%L_to_Z**2*CS%g_Earth / Rhoml(i)) * dR0_dS(i)
dB_dT = (US%L_to_Z**2*CS%g_Earth / Rhoml(i)) * dR0_dT(i)
ln_neut = 0.0 ; if (hBL_neut_h_molec > 1.0) ln_neut = log(hBL_neut_h_molec)

if (CS%find_salt_root) then
Expand Down Expand Up @@ -776,7 +776,7 @@ subroutine add_shelf_forces(G, US, CS, forces, do_shelf_area)
logical, optional, intent(in) :: do_shelf_area !< If true find the shelf-covered areas.

real :: kv_rho_ice ! The viscosity of ice divided by its density [m3 s-1 R-1 Z-1 ~> m5 kg-1 s-1].
real :: press_ice ! The pressure of the ice shelf per unit area of ocean (not ice) [Pa].
real :: press_ice ! The pressure of the ice shelf per unit area of ocean (not ice) [R L2 T-2 ~> Pa].
logical :: find_area ! If true find the shelf areas at u & v points.
type(ice_shelf_state), pointer :: ISS => NULL() ! A structure with elements that describe
! the ice-shelf state
Expand Down Expand Up @@ -811,15 +811,14 @@ subroutine add_shelf_forces(G, US, CS, forces, do_shelf_area)
endif

do j=js,je ; do i=is,ie
press_ice = (ISS%area_shelf_h(i,j) * G%IareaT(i,j)) * &
US%RZ_to_kg_m2*US%Z_to_m*US%s_to_T**2*(CS%g_Earth * ISS%mass_shelf(i,j))
press_ice = (ISS%area_shelf_h(i,j) * G%IareaT(i,j)) * (CS%g_Earth * ISS%mass_shelf(i,j))
if (associated(forces%p_surf)) then
if (.not.forces%accumulate_p_surf) forces%p_surf(i,j) = 0.0
forces%p_surf(i,j) = forces%p_surf(i,j) + US%kg_m3_to_R*US%m_s_to_L_T**2*press_ice
forces%p_surf(i,j) = forces%p_surf(i,j) + press_ice
endif
if (associated(forces%p_surf_full)) then
if (.not.forces%accumulate_p_surf) forces%p_surf_full(i,j) = 0.0
forces%p_surf_full(i,j) = forces%p_surf_full(i,j) + US%kg_m3_to_R*US%m_s_to_L_T**2*press_ice
forces%p_surf_full(i,j) = forces%p_surf_full(i,j) + press_ice
endif
enddo ; enddo

Expand Down Expand Up @@ -855,7 +854,7 @@ subroutine add_shelf_pressure(G, US, CS, fluxes)
type(ice_shelf_CS), intent(in) :: CS !< This module's control structure.
type(forcing), intent(inout) :: fluxes !< A structure of surface fluxes that may be updated.

real :: press_ice !< The pressure of the ice shelf per unit area of ocean (not ice) [Pa].
real :: press_ice !< The pressure of the ice shelf per unit area of ocean (not ice) [R L2 T-2 ~> Pa].
integer :: i, j, is, ie, js, je, isd, ied, jsd, jed
is = G%isc ; ie = G%iec ; js = G%jsc ; je = G%jec

Expand All @@ -864,15 +863,14 @@ subroutine add_shelf_pressure(G, US, CS, fluxes)
call MOM_error(FATAL,"add_shelf_pressure: Incompatible ocean and ice shelf grids.")

do j=js,je ; do i=is,ie
press_ice = (CS%ISS%area_shelf_h(i,j) * G%IareaT(i,j)) * &
US%RZ_to_kg_m2*US%Z_to_m*US%s_to_T**2*(CS%g_Earth * CS%ISS%mass_shelf(i,j))
press_ice = (CS%ISS%area_shelf_h(i,j) * G%IareaT(i,j)) * (CS%g_Earth * CS%ISS%mass_shelf(i,j))
if (associated(fluxes%p_surf)) then
if (.not.fluxes%accumulate_p_surf) fluxes%p_surf(i,j) = 0.0
fluxes%p_surf(i,j) = fluxes%p_surf(i,j) + US%kg_m3_to_R*US%m_s_to_L_T**2*press_ice
fluxes%p_surf(i,j) = fluxes%p_surf(i,j) + press_ice
endif
if (associated(fluxes%p_surf_full)) then
if (.not.fluxes%accumulate_p_surf) fluxes%p_surf_full(i,j) = 0.0
fluxes%p_surf_full(i,j) = fluxes%p_surf_full(i,j) + US%kg_m3_to_R*US%m_s_to_L_T**2*press_ice
fluxes%p_surf_full(i,j) = fluxes%p_surf_full(i,j) + press_ice
endif
enddo ; enddo

Expand All @@ -890,7 +888,6 @@ subroutine add_shelf_flux(G, US, CS, state, fluxes)
real :: frac_shelf !< The fractional area covered by the ice shelf [nondim].
real :: frac_open !< The fractional area of the ocean that is not covered by the ice shelf [nondim].
real :: delta_mass_shelf!< Change in ice shelf mass over one time step [kg s-1]
real :: press_ice !< The pressure of the ice shelf per unit area of ocean (not ice) [Pa].
real :: balancing_flux !< The fresh water flux that balances the integrated melt flux [R Z T-1 ~> kg m-2 s-1]
real :: balancing_area !< total area where the balancing flux is applied [m2]
type(time_type) :: dTime !< The time step as a time_type
Expand Down Expand Up @@ -1285,7 +1282,7 @@ subroutine initialize_ice_shelf(param_file, ocn_grid, Time, CS, diag, forces, fl

call get_param(param_file, mdl, "G_EARTH", CS%g_Earth, &
"The gravitational acceleration of the Earth.", &
units="m s-2", default = 9.80, scale=US%m_to_Z*US%T_to_s**2)
units="m s-2", default = 9.80, scale=US%m_s_to_L_T**2*US%Z_to_m)
call get_param(param_file, mdl, "C_P", CS%Cp, &
"The heat capacity of sea water, approximated as a constant. "//&
"The default value is from the TEOS-10 definition of conservative temperature.", &
Expand Down

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