source: NEMO/branches/2020/dev_r12377_KERNEL-06_techene_e3/src/OCE/ZDF/zdfmxl.F90 @ 12680

MODULE zdfmxl
   !!======================================================================
   !!                       ***  MODULE  zdfmxl  ***
   !! Ocean physics: mixed layer depth 
   !!======================================================================
   !! History :  1.0  ! 2003-08  (G. Madec)  original code
   !!            3.2  ! 2009-07  (S. Masson, G. Madec)  IOM + merge of DO-loop
   !!            3.7  ! 2012-03  (G. Madec)  make public the density criteria for trdmxl 
   !!             -   ! 2014-02  (F. Roquet)  mixed layer depth calculated using N2 instead of rhop 
   !!----------------------------------------------------------------------
   !!   zdf_mxl      : Compute the turbocline and mixed layer depths.
   !!----------------------------------------------------------------------
   USE oce            ! ocean dynamics and tracers variables
   USE isf_oce        ! ice shelf
   USE dom_oce        ! ocean space and time domain variables
   USE trc_oce  , ONLY: l_offline         ! ocean space and time domain variables
   USE zdf_oce        ! ocean vertical physics
   !
   USE in_out_manager ! I/O manager
   USE prtctl         ! Print control
   USE phycst         ! physical constants
   USE iom            ! I/O library
   USE lib_mpp        ! MPP library

   IMPLICIT NONE
   PRIVATE

   PUBLIC   zdf_mxl   ! called by zdfphy.F90

   INTEGER , PUBLIC, ALLOCATABLE, SAVE, DIMENSION(:,:) ::   nmln    !: number of level in the mixed layer (used by LDF, ZDF, TRD, TOP)
   REAL(wp), PUBLIC, ALLOCATABLE, SAVE, DIMENSION(:,:) ::   hmld    !: mixing layer depth (turbocline)      [m]   (used by TOP)
   REAL(wp), PUBLIC, ALLOCATABLE, SAVE, DIMENSION(:,:) ::   hmlp    !: mixed layer depth  (rho=rho0+zdcrit) [m]   (used by LDF)
   REAL(wp), PUBLIC, ALLOCATABLE, SAVE, DIMENSION(:,:) ::   hmlpt   !: depth of the last T-point inside the mixed layer [m] (used by LDF)

   REAL(wp), PUBLIC ::   rho_c = 0.01_wp    !: density criterion for mixed layer depth
   REAL(wp), PUBLIC ::   avt_c = 5.e-4_wp   ! Kz criterion for the turbocline depth

   !! * Substitutions
#  include "do_loop_substitute.h90"
#  include "domzgr_substitute.h90"
   !!----------------------------------------------------------------------
   !! NEMO/OCE 4.0 , NEMO Consortium (2018)
   !! $Id$ 
   !! Software governed by the CeCILL license (see ./LICENSE)
   !!----------------------------------------------------------------------
CONTAINS

   INTEGER FUNCTION zdf_mxl_alloc()
      !!----------------------------------------------------------------------
      !!               ***  FUNCTION zdf_mxl_alloc  ***
      !!----------------------------------------------------------------------
      zdf_mxl_alloc = 0      ! set to zero if no array to be allocated
      IF( .NOT. ALLOCATED( nmln ) ) THEN
         ALLOCATE( nmln(jpi,jpj), hmld(jpi,jpj), hmlp(jpi,jpj), hmlpt(jpi,jpj), STAT= zdf_mxl_alloc )
         !
         CALL mpp_sum ( 'zdfmxl', zdf_mxl_alloc )
         IF( zdf_mxl_alloc /= 0 )   CALL ctl_stop( 'STOP', 'zdf_mxl_alloc: failed to allocate arrays.' )
         !
      ENDIF
   END FUNCTION zdf_mxl_alloc


   SUBROUTINE zdf_mxl( kt, Kmm )
      !!----------------------------------------------------------------------
      !!                  ***  ROUTINE zdfmxl  ***
      !!                   
      !! ** Purpose :   Compute the turbocline depth and the mixed layer depth
      !!              with density criteria.
      !!
      !! ** Method  :   The mixed layer depth is the shallowest W depth with 
      !!      the density of the corresponding T point (just bellow) bellow a
      !!      given value defined locally as rho(10m) + rho_c
      !!               The turbocline depth is the depth at which the vertical
      !!      eddy diffusivity coefficient (resulting from the vertical physics
      !!      alone, not the isopycnal part, see trazdf.F) fall below a given
      !!      value defined locally (avt_c here taken equal to 5 cm/s2 by default)
      !!
      !! ** Action  :   nmln, hmld, hmlp, hmlpt
      !!----------------------------------------------------------------------
      INTEGER, INTENT(in) ::   kt   ! ocean time-step index
      INTEGER, INTENT(in) ::   Kmm  ! ocean time level index
      !
      INTEGER  ::   ji, jj, jk      ! dummy loop indices
      INTEGER  ::   iikn, iiki, ikt ! local integer
      REAL(wp) ::   zN2_c           ! local scalar
      INTEGER, DIMENSION(jpi,jpj) ::   imld   ! 2D workspace
      !!----------------------------------------------------------------------
      !
      IF( kt == nit000 ) THEN
         IF(lwp) WRITE(numout,*)
         IF(lwp) WRITE(numout,*) 'zdf_mxl : mixed layer depth'
         IF(lwp) WRITE(numout,*) '~~~~~~~ '
         !                             ! allocate zdfmxl arrays
         IF( zdf_mxl_alloc() /= 0 )   CALL ctl_stop( 'STOP', 'zdf_mxl : unable to allocate arrays' )
      ENDIF
      !
      ! w-level of the mixing and mixed layers
      nmln(:,:)  = nlb10               ! Initialization to the number of w ocean point
      hmlp(:,:)  = 0._wp               ! here hmlp used as a dummy variable, integrating vertically N^2
      zN2_c = grav * rho_c * r1_rau0   ! convert density criteria into N^2 criteria
      DO_3D_11_11( nlb10, jpkm1 )
         ikt = mbkt(ji,jj)
         hmlp(ji,jj) =   &
            & hmlp(ji,jj) + MAX( rn2b(ji,jj,jk) , 0._wp ) * e3w(ji,jj,jk,Kmm)
         IF( hmlp(ji,jj) < zN2_c )   nmln(ji,jj) = MIN( jk , ikt ) + 1   ! Mixed layer level
      END_3D
      !
      ! w-level of the turbocline and mixing layer (iom_use)
      imld(:,:) = mbkt(:,:) + 1        ! Initialization to the number of w ocean point
      DO_3DS_11_11( jpkm1, nlb10, -1 )
         IF( avt (ji,jj,jk) < avt_c * wmask(ji,jj,jk) )   imld(ji,jj) = jk      ! Turbocline 
      END_3D
      ! depth of the mixing and mixed layers
      DO_2D_11_11
         iiki = imld(ji,jj)
         iikn = nmln(ji,jj)
         hmld (ji,jj) = gdepw(ji,jj,iiki  ,Kmm) * ssmask(ji,jj)    ! Turbocline depth 
         hmlp (ji,jj) = gdepw(ji,jj,iikn  ,Kmm) * ssmask(ji,jj)    ! Mixed layer depth
         hmlpt(ji,jj) = gdept(ji,jj,iikn-1,Kmm) * ssmask(ji,jj)    ! depth of the last T-point inside the mixed layer
      END_2D
      !
      IF( .NOT.l_offline ) THEN
         IF( iom_use("mldr10_1") ) THEN
            IF( ln_isfcav ) THEN  ;  CALL iom_put( "mldr10_1", hmlp - risfdep)   ! mixed layer thickness
            ELSE                  ;  CALL iom_put( "mldr10_1", hmlp )            ! mixed layer depth
            END IF
         END IF
         IF( iom_use("mldkz5") ) THEN
            IF( ln_isfcav ) THEN  ;  CALL iom_put( "mldkz5"  , hmld - risfdep )   ! turbocline thickness
            ELSE                  ;  CALL iom_put( "mldkz5"  , hmld )             ! turbocline depth
            END IF
         ENDIF
      ENDIF
      !
      IF(sn_cfctl%l_prtctl)   CALL prt_ctl( tab2d_1=REAL(nmln,wp), clinfo1=' nmln : ', tab2d_2=hmlp, clinfo2=' hmlp : ' )
      !
   END SUBROUTINE zdf_mxl

   !!======================================================================
END MODULE zdfmxl