Detailed Description

Regrid columns for a z-like coordinate (z-star, z-level)

Data Types
type	zlike_cs
	Control structure containing required parameters for a z-like coordinate. More...

Functions/Subroutines
subroutine, public	init_coord_zlike (CS, nk, coordinateResolution)
	Initialise a zlike_CS with pointers to parameters. More...

subroutine, public	end_coord_zlike (CS)

subroutine, public	set_zlike_params (CS, min_thickness)

subroutine, public	build_zstar_column (CS, nz, depth, total_thickness, zInterface, z_rigid_top, eta_orig)
	Builds a z* coordinate with a minimum thickness. More...

Function/Subroutine Documentation

◆ build_zstar_column()

subroutine, public coord_zlike::build_zstar_column	(	type(zlike_cs), intent(in)	CS,
		integer, intent(in)	nz,
		real, intent(in)	depth,
		real, intent(in)	total_thickness,
		real, dimension(nz+1), intent(inout)	zInterface,
		real, intent(in), optional	z_rigid_top,
		real, intent(in), optional	eta_orig
	)

Builds a z* coordinate with a minimum thickness.

Parameters

[in]	cs	Coordinate control structure
[in]	nz	Number of levels
[in]	depth	Depth of ocean bottom (positive in m)
[in]	total_thickness	Column thickness (positive in m)
[in,out]	zinterface	Absolute positions of interfaces
[in]	z_rigid_top	The height of a rigid top (negative in m)
[in]	eta_orig	The actual original height of the top (m)

Definition at line 60 of file coord_zlike.F90.

Referenced by mom_regridding::build_zstar_grid(), and mom_diag_remap::diag_remap_update().

   type(zlike_cs),        intent(in)    :: cs !< Coordinate control structure
   integer,               intent(in)    :: nz !< Number of levels
   real,                  intent(in)    :: depth !< Depth of ocean bottom (positive in m)
   real,                  intent(in)    :: total_thickness !< Column thickness (positive in m)
   real, dimension(nz+1), intent(inout) :: zinterface !< Absolute positions of interfaces
   real, optional,        intent(in)    :: z_rigid_top !< The height of a rigid top (negative in m)
   real, optional,        intent(in)    :: eta_orig !< The actual original height of the top (m)
   ! Local variables
   real :: eta, stretching, dh, min_thickness, z0_top, z_star
   integer :: k
   logical :: new_zstar_def
 
   new_zstar_def = .false.
   min_thickness = min( cs%min_thickness, total_thickness/real(nz) )
   z0_top = 0.
   if (present(z_rigid_top)) then
     z0_top = z_rigid_top
     new_zstar_def = .true.
   endif
 
   ! Position of free-surface (or the rigid top, for which eta ~ z0_top)
   eta = total_thickness - depth
   if (present(eta_orig)) eta = eta_orig
 
   ! Conventional z* coordinate:
   !   z* = (z-eta) / stretching   where stretching = (H+eta)/H
   !   z = eta + stretching * z*
   ! The above gives z*(z=eta) = 0, z*(z=-H) = -H.
   ! With a rigid top boundary at eta = z0_top then
   !   z* = z0 + (z-eta) / stretching   where stretching = (H+eta)/(H+z0)
   !   z = eta + stretching * (z*-z0) * stretching
   stretching = total_thickness / ( depth + z0_top )
 
   if (new_zstar_def) then
     ! z_star is the notional z* coordinate in absence of upper/lower topography
     z_star = 0. ! z*=0 at the free-surface
     zinterface(1) = eta ! The actual position of the top of the column
     do k = 2,nz
       z_star = z_star - cs%coordinateResolution(k-1)
       ! This ensures that z is below a rigid upper surface (ice shelf bottom)
       zinterface(k) = min( eta + stretching * ( z_star - z0_top ), z0_top )
       ! This ensures that the layer in inflated
       zinterface(k) = min( zinterface(k), zinterface(k-1) - min_thickness )
       ! This ensures that z is above or at the topography
       zinterface(k) = max( zinterface(k), -depth + real(nz+1-k) * min_thickness )
     enddo
     zinterface(nz+1) = -depth
 
   else
     ! Integrate down from the top for a notional new grid, ignoring topography
     ! The starting position is offset by z0_top which, if z0_top<0, will place
     ! interfaces above the rigid boundary.
     zinterface(1) = eta
     do k = 1,nz
       dh = stretching * cs%coordinateResolution(k) ! Notional grid spacing
       zinterface(k+1) = zinterface(k) - dh
     enddo
 
     ! Integrating up from the bottom adjusting interface position to accommodate
     ! inflating layers without disturbing the interface above
     zinterface(nz+1) = -depth
     do k = nz,1,-1
       if ( zinterface(k) < (zinterface(k+1) + min_thickness) ) then
         zinterface(k) = zinterface(k+1) + min_thickness
       endif
     enddo
   endif
 

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◆ end_coord_zlike()

subroutine, public coord_zlike::end_coord_zlike ( type(zlike_cs), pointer CS )

Definition at line 41 of file coord_zlike.F90.

Referenced by mom_regridding::end_regridding().

   type(zlike_cs), pointer :: cs
 
   ! nothing to do
   if (.not. associated(cs)) return
   deallocate(cs%coordinateResolution)
   deallocate(cs)

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◆ init_coord_zlike()

subroutine, public coord_zlike::init_coord_zlike	(	type(zlike_cs), pointer	CS,
		integer, intent(in)	nk,
		real, dimension(:), intent(in)	coordinateResolution
	)

Initialise a zlike_CS with pointers to parameters.

Parameters

cs	Unassociated pointer to hold the control structure

Definition at line 28 of file coord_zlike.F90.

References mom_error_handler::mom_error().

   type(zlike_cs),     pointer    :: cs !< Unassociated pointer to hold the control structure
   integer,            intent(in) :: nk
   real, dimension(:), intent(in) :: coordinateresolution
 
   if (associated(cs)) call mom_error(fatal, "init_coord_zlike: CS already associated!")
   allocate(cs)
   allocate(cs%coordinateResolution(nk))
 
   cs%nk                   = nk
   cs%coordinateResolution = coordinateresolution

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◆ set_zlike_params()

subroutine, public coord_zlike::set_zlike_params	(	type(zlike_cs), pointer	CS,
		real, intent(in), optional	min_thickness
	)

Definition at line 50 of file coord_zlike.F90.