MODULE zdfric !!====================================================================== !! *** MODULE zdfric *** !! Ocean physics: vertical mixing coefficient compute from the local !! Richardson number dependent formulation !!====================================================================== !! History : OPA ! 1987-09 (P. Andrich) Original code !! 4.0 ! 1991-11 (G. Madec) !! 7.0 ! 1996-01 (G. Madec) complet rewriting of multitasking suppression of common work arrays !! 8.0 ! 1997-06 (G. Madec) complete rewriting of zdfmix !! NEMO 1.0 ! 2002-06 (G. Madec) F90: Free form and module !! 3.3 ! 2010-10 (C. Ethe, G. Madec) reorganisation of initialisation phase !!---------------------------------------------------------------------- #if defined key_zdfric || defined key_esopa !!---------------------------------------------------------------------- !! 'key_zdfric' Kz = f(Ri) !!---------------------------------------------------------------------- !! zdf_ric : update momentum and tracer Kz from the Richardson !! number computation !! zdf_ric_init : initialization, namelist read, & parameters control !!---------------------------------------------------------------------- USE oce ! ocean dynamics and tracers variables USE dom_oce ! ocean space and time domain variables USE zdf_oce ! ocean vertical physics USE in_out_manager ! I/O manager USE lbclnk ! ocean lateral boundary condition (or mpp link) IMPLICIT NONE PRIVATE PUBLIC zdf_ric ! called by step.F90 PUBLIC zdf_ric_init ! called by opa.F90 LOGICAL, PUBLIC, PARAMETER :: lk_zdfric = .TRUE. !: Richardson vertical mixing flag ! !!* Namelist namzdf_ric : Richardson number dependent Kz * INTEGER :: nn_ric = 2 ! coefficient of the parameterization REAL(wp) :: rn_avmri = 100.e-4_wp ! maximum value of the vertical eddy viscosity REAL(wp) :: rn_alp = 5._wp ! coefficient of the parameterization REAL(wp), DIMENSION(jpi,jpj,jpk) :: tmric ! coef. for the horizontal mean at t-point !! * Substitutions # include "domzgr_substitute.h90" !!---------------------------------------------------------------------- !! NEMO/OPA 3.3 , NEMO Consortium (2010) !! $Id$ !! Software governed by the CeCILL licence (NEMOGCM/NEMO_CeCILL.txt) !!---------------------------------------------------------------------- CONTAINS SUBROUTINE zdf_ric( kt ) !!---------------------------------------------------------------------- !! *** ROUTINE zdfric *** !! !! ** Purpose : Compute the before eddy viscosity and diffusivity as !! a function of the local richardson number. !! !! ** Method : Local richardson number dependent formulation of the !! vertical eddy viscosity and diffusivity coefficients. !! The eddy coefficients are given by: !! avm = avm0 + avmb !! avt = avm0 / (1 + rn_alp*ri) !! with ri = N^2 / dz(u)**2 !! = e3w**2 * rn2/[ mi( dk(ub) )+mj( dk(vb) ) ] !! avm0= rn_avmri / (1 + rn_alp*ri)**nn_ric !! Where ri is the before local Richardson number, !! rn_avmri is the maximum value reaches by avm and avt !! avmb and avtb are the background (or minimum) values !! and rn_alp, nn_ric are adjustable parameters. !! Typical values used are : avm0=1.e-2 m2/s, avmb=1.e-6 m2/s !! avtb=1.e-7 m2/s, rn_alp=5. and nn_ric=2. !! a numerical threshold is impose on the vertical shear (1.e-20) !! N.B. the mask are required for implicit scheme, and surface !! and bottom value already set in zdfini.F90 !! !! References : Pacanowski & Philander 1981, JPO, 1441-1451. !!---------------------------------------------------------------------- INTEGER, INTENT( in ) :: kt ! ocean time-step indexocean time step !! INTEGER :: ji, jj, jk ! dummy loop indices REAL(wp) :: zcoef, zdku, zdkv, zri, z05alp ! temporary scalars REAL(wp), DIMENSION(jpi,jpj) :: zwx ! temporary workspace !!---------------------------------------------------------------------- ! ! =============== DO jk = 2, jpkm1 ! Horizontal slab ! ! =============== ! Richardson number (put in zwx(ji,jj)) ! ----------------- DO jj = 2, jpjm1 DO ji = 2, jpim1 zcoef = 0.5 / fse3w(ji,jj,jk) ! ! shear of horizontal velocity zdku = zcoef * ( ub(ji-1,jj,jk-1) + ub(ji,jj,jk-1) & & -ub(ji-1,jj,jk ) - ub(ji,jj,jk ) ) zdkv = zcoef * ( vb(ji,jj-1,jk-1) + vb(ji,jj,jk-1) & & -vb(ji,jj-1,jk ) - vb(ji,jj,jk ) ) ! ! richardson number (minimum value set to zero) zri = rn2(ji,jj,jk) / ( zdku*zdku + zdkv*zdkv + 1.e-20 ) zwx(ji,jj) = MAX( zri, 0.e0 ) END DO END DO CALL lbc_lnk( zwx, 'W', 1. ) ! Boundary condition (sign unchanged) ! Vertical eddy viscosity and diffusivity coefficients ! ------------------------------------------------------- z05alp = 0.5 * rn_alp DO jj = 1, jpjm1 ! Eddy viscosity coefficients (avm) DO ji = 1, jpim1 avmu(ji,jj,jk) = umask(ji,jj,jk) & & * rn_avmri / ( 1. + z05alp*( zwx(ji+1,jj)+zwx(ji,jj) ) )**nn_ric avmv(ji,jj,jk) = vmask(ji,jj,jk) & & * rn_avmri / ( 1. + z05alp*( zwx(ji,jj+1)+zwx(ji,jj) ) )**nn_ric END DO END DO DO jj = 2, jpjm1 ! Eddy diffusivity coefficients (avt) DO ji = 2, jpim1 avt(ji,jj,jk) = tmric(ji,jj,jk) / ( 1. + rn_alp * zwx(ji,jj) ) & & * ( avmu(ji,jj,jk) + avmu(ji-1, jj ,jk) & & + avmv(ji,jj,jk) + avmv( ji ,jj-1,jk) ) & & + avtb(jk) * tmask(ji,jj,jk) ! ! Add the background coefficient on eddy viscosity avmu(ji,jj,jk) = avmu(ji,jj,jk) + avmb(jk) * umask(ji,jj,jk) avmv(ji,jj,jk) = avmv(ji,jj,jk) + avmb(jk) * vmask(ji,jj,jk) END DO END DO ! ! =============== END DO ! End of slab ! ! =============== ! CALL lbc_lnk( avt , 'W', 1. ) ! Boundary conditions (unchanged sign) CALL lbc_lnk( avmu, 'U', 1. ) ; CALL lbc_lnk( avmv, 'V', 1. ) ! END SUBROUTINE zdf_ric SUBROUTINE zdf_ric_init !!---------------------------------------------------------------------- !! *** ROUTINE zdfbfr_init *** !! !! ** Purpose : Initialization of the vertical eddy diffusivity and !! viscosity coef. for the Richardson number dependent formulation. !! !! ** Method : Read the namzdf_ric namelist and check the parameter values !! !! ** input : Namelist namzdf_ric !! !! ** Action : increase by 1 the nstop flag is setting problem encounter !!---------------------------------------------------------------------- INTEGER :: ji, jj, jk ! dummy loop indices !! NAMELIST/namzdf_ric/ rn_avmri, rn_alp, nn_ric !!---------------------------------------------------------------------- ! REWIND( numnam ) ! Read Namelist namzdf_ric : richardson number dependent Kz READ ( numnam, namzdf_ric ) ! IF(lwp) THEN ! Control print WRITE(numout,*) WRITE(numout,*) 'zdf_ric : Ri depend vertical mixing scheme' WRITE(numout,*) '~~~~~~~' WRITE(numout,*) ' Namelist namzdf_ric : set Kz(Ri) parameters' WRITE(numout,*) ' maximum vertical viscosity rn_avmri = ', rn_avmri WRITE(numout,*) ' coefficient rn_alp = ', rn_alp WRITE(numout,*) ' coefficient nn_ric = ', nn_ric ENDIF ! DO jk = 1, jpk ! weighting mean array tmric for 4 T-points which accounts for coastal boundary conditions. DO jj = 2, jpj DO ji = 2, jpi tmric(ji,jj,jk) = tmask(ji,jj,jk) & & / MAX( 1., umask(ji-1,jj ,jk) + umask(ji,jj,jk) & & + vmask(ji ,jj-1,jk) + vmask(ji,jj,jk) ) END DO END DO END DO tmric(:,1,:) = 0.e0 ! DO jk = 1, jpk ! Initialization of vertical eddy coef. to the background value avt (:,:,jk) = avtb(jk) * tmask(:,:,jk) avmu(:,:,jk) = avmb(jk) * umask(:,:,jk) avmv(:,:,jk) = avmb(jk) * vmask(:,:,jk) END DO ! END SUBROUTINE zdf_ric_init #else !!---------------------------------------------------------------------- !! Dummy module : NO Richardson dependent vertical mixing !!---------------------------------------------------------------------- LOGICAL, PUBLIC, PARAMETER :: lk_zdfric = .FALSE. !: Richardson mixing flag CONTAINS SUBROUTINE zdf_ric_init ! Dummy routine END SUBROUTINE zdf_ric_init SUBROUTINE zdf_ric( kt ) ! Dummy routine WRITE(*,*) 'zdf_ric: You should not have seen this print! error?', kt END SUBROUTINE zdf_ric #endif !!====================================================================== END MODULE zdfric