mom_interface_heights Module Reference

Detailed Description

The module calculates interface heights, including free surface height.

Data Types
interface	find_eta

Functions/Subroutines
subroutine	find_eta_3d (h, tv, G_Earth, G, GV, eta, eta_bt, halo_size)
subroutine	find_eta_2d (h, tv, G_Earth, G, GV, eta, eta_bt, halo_size)

Function/Subroutine Documentation

find_eta_2d()

subroutine mom_interface_heights::find_eta_2d ( real, dimension(szi_(g),szj_(g),szk_(g)), intent(in)  h, type(thermo_var_ptrs), intent(in)  tv, real, intent(in)  G_Earth, type(ocean_grid_type), intent(in)  G, type(verticalgrid_type), intent(in)  GV, real, dimension(szi_(g),szj_(g)), intent(out)  eta, real, dimension(szi_(g),szj_(g)), intent(in), optional  eta_bt, integer, intent(in), optional  halo_size  )

private

Parameters

[in]	g	The ocean's grid structure.
[in]	gv	The ocean's vertical grid structure.
[in]	h	Layer thicknesses, in H (usually m or kg m-2).
[in]	tv	A structure pointing to various thermodynamic variables.
[in]	g_earth	Earth gravitational acceleration (m/s2).
[out]	eta	free surface height relative to mean sea level (z=0) (m).
[in]	eta_bt	optional barotropic variable that gives the "correct" free surface height (Boussinesq) or total water column mass per unit aread (non-Boussinesq), in H (m or kg m-2).
[in]	halo_size	width of halo points on which to calculate eta.

Definition at line 200 of file MOM_interface_heights.F90.

References mom_eos::int_specific_vol_dp().

  type(ocean_grid_type),                      intent(in)  :: g        !< The ocean's grid structure.
  type(verticalgrid_type),                    intent(in)  :: gv       !< The ocean's vertical grid
                                                                      !! structure.
  real, dimension(SZI_(G),SZJ_(G),SZK_(G)),   intent(in)  :: h        !< Layer thicknesses, in H
                                                                      !! (usually m or kg m-2).
  type(thermo_var_ptrs),                      intent(in)  :: tv       !< A structure pointing to
                                                                      !! various thermodynamic
                                                                      !! variables.
  real,                                       intent(in)  :: g_earth  !< Earth gravitational
                                                                      !! acceleration (m/s2).
  real, dimension(SZI_(G),SZJ_(G)),           intent(out) :: eta      !< free surface height
                                                                      !! relative to mean sea
                                                                      !! level (z=0) (m).
  real, dimension(SZI_(G),SZJ_(G)), optional, intent(in)  :: eta_bt   !< optional barotropic
                   !! variable that gives the "correct" free surface height (Boussinesq) or total
                   !! water column mass per unit aread (non-Boussinesq), in H (m or kg m-2).
  integer,                          optional, intent(in)  :: halo_size !< width of halo points on
                                                                       !! which to calculate eta.

!   This subroutine determines the free surface height, using the appropriate
! form for consistency with the calculation of the pressure gradient forces.
! Additionally, the sea surface height may be adjusted for consistency with the
! corresponding time-average quantity from the barotropic calculation.

! Arguments:
!  (in)       h      - layer thickness (meter or kg/m2)
!  (in)      tv      - structure pointing to various thermodynamic variables
!  (in)      G_Earth - Earth gravitational acceleration (m/s2)
!  (in)      G       - ocean grid structure
!  (in)      GV      - The ocean's vertical grid structure.
!  (out)     eta     - free surface height relative to mean sea level (z=0) (m)
!  (in,opt)  eta_bt  - optional barotropic variable that gives the "correct"
!                      free surface height (Boussinesq) or total water column
!                      mass per unit aread (non-Boussinesq), in H (m or kg m-2)
!  (in,opt)  halo_size - width of halo points on which to calculate eta

  real, dimension(SZI_(G),SZJ_(G),SZK_(G)+1) :: &
    p     ! The pressure in Pa.
  real, dimension(SZI_(G),SZJ_(G),SZK_(G)) :: &
    dz_geo     ! The change in geopotential height across a layer, in m2 s-2.
  real :: htot(szi_(g))  ! The sum of all layers' thicknesses, in kg m-2 or m.
  real :: i_gearth
  integer i, j, k, is, ie, js, je, nz, halo

  halo = 0 ; if (present(halo_size)) halo = max(0,halo_size)
  is = g%isc-halo ; ie = g%iec+halo ; js = g%jsc-halo ; je = g%jec+halo
  nz = g%ke

  i_gearth = 1.0 / g_earth

!$OMP parallel default(none) shared(is,ie,js,je,nz,eta,G,GV,eta_bt,h,tv,p, &
!$OMP                               G_Earth,dz_geo,halo,I_gEarth) &
!$OMP                       private(htot)
!$OMP do
  do j=js,je ; do i=is,ie ; eta(i,j) = -g%bathyT(i,j) ; enddo ; enddo

  if (gv%Boussinesq) then
    if (present(eta_bt)) then
!$OMP do
      do j=js,je ; do i=is,ie
        eta(i,j) = eta_bt(i,j)
      enddo ; enddo
    else
!$OMP do
      do j=js,je ; do k=1,nz ; do i=is,ie
        eta(i,j) = eta(i,j) + h(i,j,k)*gv%H_to_m
      enddo ; enddo ; enddo
    endif
  else
    if (associated(tv%eqn_of_state)) then
!$OMP do
      do j=js,je
        do i=is,ie ; p(i,j,1) = 0.0 ; enddo

        do k=1,nz ; do i=is,ie
          p(i,j,k+1) = p(i,j,k) + g_earth*gv%H_to_kg_m2*h(i,j,k)
        enddo ; enddo
      enddo
!$OMP do
      do k = 1, nz
        call int_specific_vol_dp(tv%T(:,:,k), tv%S(:,:,k), p(:,:,k), p(:,:,k+1), 0.0, &
                                 g%HI, tv%eqn_of_state, dz_geo(:,:,k), halo_size=halo)
      enddo
!$OMP do
      do j=js,je ; do k=1,nz ; do i=is,ie
          eta(i,j) = eta(i,j) + i_gearth * dz_geo(i,j,k)
      enddo ; enddo ; enddo
    else
!$OMP do
      do j=js,je ; do k=1,nz ; do i=is,ie
        eta(i,j) = eta(i,j) + gv%H_to_kg_m2*h(i,j,k)/gv%Rlay(k)
      enddo ; enddo ; enddo
    endif
    if (present(eta_bt)) then
      !   Dilate the water column to agree with the the time-averaged column
      ! mass from the barotropic solution.
!$OMP do
      do j=js,je
        do i=is,ie ; htot(i) = gv%H_subroundoff ; enddo
        do k=1,nz ; do i=is,ie ; htot(i) = htot(i) + h(i,j,k) ; enddo ; enddo
        do i=is,ie
          eta(i,j) = (eta_bt(i,j) / htot(i)) * (eta(i,j) + g%bathyT(i,j)) - &
                     g%bathyT(i,j)
        enddo
      enddo
    endif
  endif
!$OMP end parallel

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find_eta_3d()

subroutine mom_interface_heights::find_eta_3d ( real, dimension( g %isd: g %ied, g %jsd: g %jed, g %ke), intent(in)  h, type(thermo_var_ptrs), intent(in)  tv, real, intent(in)  G_Earth, type(ocean_grid_type), intent(in)  G, type(verticalgrid_type), intent(in)  GV, real, dimension( g %isd: g %ied, g %jsd: g %jed, g %ke+1), intent(out)  eta, real, dimension( g %isd: g %ied, g %jsd: g %jed), intent(in), optional  eta_bt, integer, intent(in), optional  halo_size  )

private

Parameters

[in]	g	The ocean's grid structure.
[in]	gv	The ocean's vertical grid structure.
[in]	h	Layer thicknesses, in H (usually m or kg m-2).
[in]	tv	A structure pointing to various thermodynamic variables.
[in]	g_earth	Earth gravitational acceleration (m/s2).
[out]	eta	layer interface heights (meter).
[in]	eta_bt	optional barotropic variable that gives the "correct" free surface height (Boussinesq) or total water column mass per unit aread (non-Boussinesq). This is used to dilate the layer. thicknesses when calculating interfaceheights, in H (m or kg m-2).
[in]	halo_size	width of halo points on which to calculate eta.

Definition at line 70 of file MOM_interface_heights.F90.

References mom_eos::int_specific_vol_dp(), and mom_error_handler::mom_error().

  type(ocean_grid_type),                      intent(in)  :: g         !< The ocean's grid
                                                                       !! structure.
  type(verticalgrid_type),                    intent(in)  :: gv        !< The ocean's vertical
                                                                       !! grid structure.
  real, dimension(SZI_(G),SZJ_(G),SZK_(G)),   intent(in)  :: h         !< Layer thicknesses, in H
                                                                       !! (usually m or kg m-2).
  type(thermo_var_ptrs),                      intent(in)  :: tv        !< A structure pointing to
                                                                       !! various thermodynamic
                                                                       !! variables.
  real,                                       intent(in)  :: g_earth   !< Earth gravitational
                                                                       !! acceleration (m/s2).
  real, dimension(SZI_(G),SZJ_(G),SZK_(G)+1), intent(out) :: eta       !< layer interface heights
                                                                       !! (meter).
  real, dimension(SZI_(G),SZJ_(G)), optional, intent(in)  :: eta_bt    !< optional barotropic
             !! variable that gives the "correct" free surface height (Boussinesq) or total water
             !! column mass per unit aread (non-Boussinesq).  This is used to dilate the layer.
             !! thicknesses when calculating interfaceheights, in H (m or kg m-2).
  integer,                          optional, intent(in)  :: halo_size !< width of halo points on
                                                                       !! which to calculate eta.

!   This subroutine determines the heights of all interfaces between layers,
! using the appropriate form for consistency with the calculation of the
! pressure gradient forces.  Additionally, these height may be dilated for
! consistency with the corresponding time-average quantity from the barotropic
! calculation.

! Arguments:
!  (in)      h       - layer thickness H (meter or kg/m2)
!  (in)      tv      - structure pointing to thermodynamic variables
!  (in)      G_Earth - Earth gravitational acceleration (m/s2)
!  (in)      G       - ocean grid structure
!  (in)      GV      - The ocean's vertical grid structure.
!  (out)     eta     - layer interface heights (meter)
!  (in,opt)  eta_bt  - optional barotropic variable that gives the "correct"
!                      free surface height (Boussinesq) or total water column
!                      mass per unit aread (non-Boussinesq).  This is used to
!                      dilate the layer thicknesses when calculating interface
!                      heights, in H (m or kg m-2).
! (in,opt) halo_size - width of halo points on which to calculate eta

  real :: p(szi_(g),szj_(g),szk_(g)+1)
  real :: dz_geo(szi_(g),szj_(g),szk_(g)) ! The change in geopotential height
                                          ! across a layer, in m2 s-2.
  real :: dilate(szi_(g))                 ! non-dimensional dilation factor
  real :: htot(szi_(g))                   ! total thickness H
  real :: i_gearth
  integer i, j, k, isv, iev, jsv, jev, nz, halo

  halo = 0 ; if (present(halo_size)) halo = max(0,halo_size)

  isv = g%isc-halo ; iev = g%iec+halo ; jsv = g%jsc-halo ; jev = g%jec+halo
  nz = g%ke

  if ((isv<g%isd) .or. (iev>g%ied) .or. (jsv<g%jsd) .or. (jev>g%jed)) &
    call mom_error(fatal,"find_eta called with an overly large halo_size.")

  i_gearth = 1.0 / g_earth

!$OMP parallel default(none) shared(isv,iev,jsv,jev,nz,eta,G,GV,h,eta_bt,tv,p, &
!$OMP                               G_Earth,dz_geo,halo,I_gEarth) &
!$OMP                       private(dilate,htot)
!$OMP do
  do j=jsv,jev ; do i=isv,iev ; eta(i,j,nz+1) = -g%bathyT(i,j) ; enddo ; enddo

  if (gv%Boussinesq) then
!$OMP do
    do j=jsv,jev ; do k=nz,1,-1; do i=isv,iev
      eta(i,j,k) = eta(i,j,k+1) + h(i,j,k)*gv%H_to_m
    enddo ; enddo ; enddo
    if (present(eta_bt)) then
      ! Dilate the water column to agree with the free surface height
      ! that is used for the dynamics.
!$OMP do
      do j=jsv,jev
        do i=isv,iev
          dilate(i) = (eta_bt(i,j)*gv%H_to_m + g%bathyT(i,j)) / &
                      (eta(i,j,1) + g%bathyT(i,j))
        enddo
        do k=1,nz ; do i=isv,iev
          eta(i,j,k) = dilate(i) * (eta(i,j,k) + g%bathyT(i,j)) - g%bathyT(i,j)
        enddo ; enddo
      enddo
    endif
  else
    if (associated(tv%eqn_of_state)) then
      ! ### THIS SHOULD BE P_SURF, IF AVAILABLE.
!$OMP do
      do j=jsv,jev
        do i=isv,iev ; p(i,j,1) = 0.0 ; enddo
        do k=1,nz ; do i=isv,iev
          p(i,j,k+1) = p(i,j,k) + g_earth*gv%H_to_kg_m2*h(i,j,k)
        enddo ; enddo
      enddo
!$OMP do
      do k=1,nz
        call int_specific_vol_dp(tv%T(:,:,k), tv%S(:,:,k), p(:,:,k), p(:,:,k+1), &
                                 0.0, g%HI, tv%eqn_of_state, dz_geo(:,:,k), halo_size=halo)
      enddo
!$OMP do
      do j=jsv,jev
        do k=nz,1,-1 ; do i=isv,iev
          eta(i,j,k) = eta(i,j,k+1) + i_gearth * dz_geo(i,j,k)
        enddo ; enddo
      enddo
    else
!$OMP do
      do j=jsv,jev ;  do k=nz,1,-1; do i=isv,iev
        eta(i,j,k) = eta(i,j,k+1) + gv%H_to_kg_m2*h(i,j,k)/gv%Rlay(k)
      enddo ; enddo ; enddo
    endif
    if (present(eta_bt)) then
      ! Dilate the water column to agree with the free surface height
      ! from the time-averaged barotropic solution.
!$OMP do
      do j=jsv,jev
        do i=isv,iev ; htot(i) = gv%H_subroundoff ; enddo
        do k=1,nz ; do i=isv,iev ; htot(i) = htot(i) + h(i,j,k) ; enddo ; enddo
        do i=isv,iev ; dilate(i) = eta_bt(i,j) / htot(i) ; enddo
        do k=1,nz ; do i=isv,iev
          eta(i,j,k) = dilate(i) * (eta(i,j,k) + g%bathyT(i,j)) - g%bathyT(i,j)
        enddo ; enddo
      enddo
    endif
  endif
!$OMP end parallel

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