| 1 | MODULE zdfric |
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| 2 | !!====================================================================== |
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| 3 | !! *** MODULE zdfric *** |
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| 4 | !! Ocean physics: vertical mixing coefficient compute from the local |
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| 5 | !! Richardson number dependent formulation |
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| 6 | !!====================================================================== |
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| 7 | #if defined key_zdfric || defined key_esopa |
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| 8 | !!---------------------------------------------------------------------- |
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| 9 | !! 'key_zdfric' Kz = f(Ri) |
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| 10 | !!---------------------------------------------------------------------- |
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| 11 | !! zdf_ric : update momentum and tracer Kz from the Richardson |
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| 12 | !! number computation |
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| 13 | !! zdf_ric_init : initialization, namelist read, & parameters control |
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| 14 | !!---------------------------------------------------------------------- |
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| 15 | USE oce ! ocean dynamics and tracers variables |
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| 16 | USE dom_oce ! ocean space and time domain variables |
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| 17 | USE zdf_oce ! ocean vertical physics |
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| 18 | USE in_out_manager ! I/O manager |
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| 19 | USE lbclnk ! ocean lateral boundary condition (or mpp link) |
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| 20 | |
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| 21 | IMPLICIT NONE |
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| 22 | PRIVATE |
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| 23 | |
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| 24 | PUBLIC zdf_ric ! called by step.F90 |
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| 25 | |
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| 26 | LOGICAL, PUBLIC, PARAMETER :: lk_zdfric = .TRUE. !: Richardson vertical mixing flag |
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| 27 | |
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| 28 | ! !!* Namelist nam_ric : Richardson number dependent Kz * |
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| 29 | INTEGER :: nn_ric = 2 ! coefficient of the parameterization |
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| 30 | REAL(wp) :: rn_avmri = 100.e-4_wp ! maximum value of the vertical eddy viscosity |
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| 31 | REAL(wp) :: rn_alp = 5._wp ! coefficient of the parameterization |
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| 32 | |
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| 33 | REAL(wp), DIMENSION(jpi,jpj,jpk) :: tmric ! coef. for the horizontal mean at t-point |
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| 34 | |
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| 35 | !! * Substitutions |
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| 36 | # include "domzgr_substitute.h90" |
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| 37 | !!---------------------------------------------------------------------- |
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| 38 | !! NEMO/OPA 3.2 , LOCEAN-IPSL (2009) |
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| 39 | !! $Id$ |
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| 40 | !! Software governed by the CeCILL licence (modipsl/doc/NEMO_CeCILL.txt) |
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| 41 | !!---------------------------------------------------------------------- |
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| 42 | CONTAINS |
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| 43 | |
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| 44 | SUBROUTINE zdf_ric( kt ) |
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| 45 | !!---------------------------------------------------------------------- |
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| 46 | !! *** ROUTINE zdfric *** |
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| 47 | !! |
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| 48 | !! ** Purpose : Compute the before eddy viscosity and diffusivity as |
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| 49 | !! a function of the local richardson number. |
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| 50 | !! |
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| 51 | !! ** Method : Local richardson number dependent formulation of the |
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| 52 | !! vertical eddy viscosity and diffusivity coefficients. the eddy |
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| 53 | !! coefficients are given by: |
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| 54 | !! avm = avm0 + avmb |
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| 55 | !! avt = avm0 / (1 + rn_alp*ri) |
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| 56 | !! with ri = N^2 / dz(u)**2 |
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| 57 | !! = e3w**2 * rn2/[ mi( dk(ub) )+mj( dk(vb) ) ] |
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| 58 | !! avm0= rn_avmri / (1 + rn_alp*ri)**nn_ric |
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| 59 | !! Where ri is the before local Richardson number, rn_avmri the maximum |
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| 60 | !! value reaches by the vertical eddy coefficients, avmb and avtb |
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| 61 | !! the background (or minimum) values of these coefficients for |
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| 62 | !! momemtum and tracers, and rn_alp, nn_ric are adjustable parameters. |
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| 63 | !! typical values used are : avm0=1.e-2 m2/s, avmb=1.e-6 m2/s |
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| 64 | !! avtb=1.e-7 m2/s, rn_alp=5. and nn_ric=2. |
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| 65 | !! this formulation needs ri>=0 : ri is set to zero if dz(rau)<0. |
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| 66 | !! a numerical threshold is impose on the vertical shear (1.e-20) |
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| 67 | !! N.B. the mask are required for implicit scheme, and surface |
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| 68 | !! and bottom value already set in inimix.F |
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| 69 | !! |
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| 70 | !! References : |
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| 71 | !! pacanowski & philander 1981, j. phys. oceanogr., 1441-1451. |
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| 72 | !! History : |
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| 73 | !! ! 87-09 (P. Andrich) Original code |
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| 74 | !! ! 91-11 (G. Madec) |
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| 75 | !! ! 93-03 (M. Guyon) symetrical conditions |
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| 76 | !! ! 96-01 (G. Madec) complet rewriting of multitasking |
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| 77 | !! suppression of common work arrays |
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| 78 | !! ! 97-06 (G. Madec) complete rewriting of zdfmix |
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| 79 | !! 8.5 ! 02-06 (G. Madec) F90: Free form and module |
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| 80 | !!---------------------------------------------------------------------- |
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| 81 | INTEGER, INTENT( in ) :: kt ! ocean time-step indexocean time step |
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| 82 | !! |
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| 83 | INTEGER :: ji, jj, jk ! dummy loop indices |
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| 84 | REAL(wp) :: zcoef, zdku, zdkv, zri, z05alp ! temporary scalars |
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| 85 | REAL(wp), DIMENSION(jpi,jpj) :: zwx ! temporary workspace |
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| 86 | !!---------------------------------------------------------------------- |
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| 87 | |
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| 88 | IF( kt == nit000 ) CALL zdf_ric_init ! Initialization (first time-step only) |
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| 89 | |
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| 90 | ! ! =============== |
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| 91 | DO jk = 2, jpkm1 ! Horizontal slab |
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| 92 | ! ! =============== |
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| 93 | ! Richardson number (put in zwx(ji,jj)) |
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| 94 | ! ----------------- |
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| 95 | ! minimum value set to zero |
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| 96 | DO jj = 2, jpjm1 |
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| 97 | DO ji = 2, jpim1 |
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| 98 | zcoef = 0.5 / fse3w(ji,jj,jk) |
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| 99 | ! shear of horizontal velocity |
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| 100 | zdku = zcoef * ( ub(ji-1,jj,jk-1) + ub(ji,jj,jk-1) & |
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| 101 | & -ub(ji-1,jj,jk ) - ub(ji,jj,jk ) ) |
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| 102 | zdkv = zcoef * ( vb(ji,jj-1,jk-1) + vb(ji,jj,jk-1) & |
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| 103 | & -vb(ji,jj-1,jk ) - vb(ji,jj,jk ) ) |
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| 104 | ! richardson number (minimum value set to zero) |
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| 105 | zri = rn2(ji,jj,jk) / ( zdku*zdku + zdkv*zdkv + 1.e-20 ) |
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| 106 | zwx(ji,jj) = MAX( zri, 0.e0 ) |
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| 107 | END DO |
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| 108 | END DO |
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| 109 | |
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| 110 | ! Boundary condition on zwx (sign unchanged) |
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| 111 | CALL lbc_lnk( zwx, 'W', 1. ) |
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| 112 | |
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| 113 | |
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| 114 | ! Vertical eddy viscosity and diffusivity coefficients |
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| 115 | ! ------------------------------------------------------- |
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| 116 | ! Eddy viscosity coefficients |
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| 117 | z05alp = 0.5 * rn_alp |
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| 118 | DO jj = 1, jpjm1 |
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| 119 | DO ji = 1, jpim1 |
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| 120 | avmu(ji,jj,jk) = umask(ji,jj,jk) & |
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| 121 | & * rn_avmri / ( 1. + z05alp*( zwx(ji+1,jj)+zwx(ji,jj) ) )**nn_ric |
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| 122 | avmv(ji,jj,jk) = vmask(ji,jj,jk) & |
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| 123 | & * rn_avmri / ( 1. + z05alp*( zwx(ji,jj+1)+zwx(ji,jj) ) )**nn_ric |
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| 124 | END DO |
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| 125 | END DO |
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| 126 | |
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| 127 | ! Eddy diffusivity coefficients |
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| 128 | DO jj = 2, jpjm1 |
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| 129 | DO ji = 2, jpim1 |
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| 130 | avt(ji,jj,jk) = tmric(ji,jj,jk) / ( 1. + rn_alp * zwx(ji,jj) ) & |
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| 131 | & * ( avmu(ji,jj,jk) + avmu(ji-1, jj ,jk) & |
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| 132 | & + avmv(ji,jj,jk) + avmv( ji ,jj-1,jk) ) & |
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| 133 | & + avtb(jk) * tmask(ji,jj,jk) |
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| 134 | END DO |
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| 135 | END DO |
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| 136 | |
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| 137 | ! Add the background coefficient on eddy viscosity |
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| 138 | DO jj = 2, jpjm1 |
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| 139 | DO ji = 2, jpim1 |
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| 140 | avmu(ji,jj,jk) = avmu(ji,jj,jk) + avmb(jk) * umask(ji,jj,jk) |
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| 141 | avmv(ji,jj,jk) = avmv(ji,jj,jk) + avmb(jk) * vmask(ji,jj,jk) |
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| 142 | END DO |
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| 143 | END DO |
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| 144 | ! ! =============== |
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| 145 | END DO ! End of slab |
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| 146 | ! ! =============== |
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| 147 | |
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| 148 | ! Boundary conditions on (avt,avmu,avmv) (unchanged sign) |
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| 149 | ! -----------------------=============== |
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| 150 | CALL lbc_lnk( avt , 'W', 1. ) |
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| 151 | CALL lbc_lnk( avmu, 'U', 1. ) |
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| 152 | CALL lbc_lnk( avmv, 'V', 1. ) |
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| 153 | |
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| 154 | END SUBROUTINE zdf_ric |
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| 155 | |
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| 156 | |
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| 157 | SUBROUTINE zdf_ric_init |
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| 158 | !!---------------------------------------------------------------------- |
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| 159 | !! *** ROUTINE zdfbfr_init *** |
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| 160 | !! |
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| 161 | !! ** Purpose : Initialization of the vertical eddy diffusivity and |
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| 162 | !! viscosity coef. for the Richardson number dependent formulation. |
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| 163 | !! |
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| 164 | !! ** Method : Read the namric namelist and check the parameter values |
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| 165 | !! |
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| 166 | !! ** input : Namelist namric |
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| 167 | !! |
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| 168 | !! ** Action : increase by 1 the nstop flag is setting problem encounter |
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| 169 | !! |
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| 170 | !! history : |
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| 171 | !! 8.5 ! 02-06 (G. Madec) original code |
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| 172 | !!---------------------------------------------------------------------- |
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| 173 | INTEGER :: ji, jj, jk ! dummy loop indices |
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| 174 | !! |
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| 175 | NAMELIST/nam_ric/ rn_avmri, rn_alp, nn_ric |
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| 176 | !!---------------------------------------------------------------------- |
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| 177 | |
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| 178 | REWIND ( numnam ) ! Read Namelist nam_ric : richardson number dependent Kz |
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| 179 | READ ( numnam, nam_ric ) |
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| 180 | |
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| 181 | IF(lwp) THEN ! Control print |
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| 182 | WRITE(numout,*) |
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| 183 | WRITE(numout,*) 'zdf_ric : Ri depend vertical mixing scheme' |
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| 184 | WRITE(numout,*) '~~~~~~~' |
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| 185 | WRITE(numout,*) ' Namelist namric : set Kz(Ri) parameters' |
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| 186 | WRITE(numout,*) ' maximum vertical viscosity rn_avmri = ', rn_avmri |
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| 187 | WRITE(numout,*) ' coefficient rn_alp = ', rn_alp |
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| 188 | WRITE(numout,*) ' coefficient nn_ric = ', nn_ric |
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| 189 | ENDIF |
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| 190 | |
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| 191 | ! weighting mean array tmric for 4 T-points which accounts for coastal boundary conditions. |
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| 192 | DO jk = 1, jpk |
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| 193 | DO jj = 2, jpj |
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| 194 | DO ji = 2, jpi |
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| 195 | tmric(ji,jj,jk) = tmask(ji,jj,jk) & |
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| 196 | / MAX( 1., umask(ji-1,jj ,jk) + umask(ji,jj,jk) & |
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| 197 | + vmask(ji ,jj-1,jk) + vmask(ji,jj,jk) ) |
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| 198 | END DO |
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| 199 | END DO |
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| 200 | END DO |
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| 201 | tmric(:,1,:) = 0.e0 |
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| 202 | |
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| 203 | ! Initialization of vertical eddy coef. to the background value |
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| 204 | DO jk = 1, jpk |
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| 205 | avt (:,:,jk) = avtb(jk) * tmask(:,:,jk) |
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| 206 | avmu(:,:,jk) = avmb(jk) * umask(:,:,jk) |
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| 207 | avmv(:,:,jk) = avmb(jk) * vmask(:,:,jk) |
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| 208 | END DO |
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| 209 | |
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| 210 | END SUBROUTINE zdf_ric_init |
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| 211 | |
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| 212 | #else |
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| 213 | !!---------------------------------------------------------------------- |
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| 214 | !! Dummy module : NO Richardson dependent vertical mixing |
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| 215 | !!---------------------------------------------------------------------- |
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| 216 | LOGICAL, PUBLIC, PARAMETER :: lk_zdfric = .FALSE. !: Richardson mixing flag |
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| 217 | CONTAINS |
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| 218 | SUBROUTINE zdf_ric( kt ) ! Dummy routine |
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| 219 | WRITE(*,*) 'zdf_ric: You should not have seen this print! error?', kt |
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| 220 | END SUBROUTINE zdf_ric |
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| 221 | #endif |
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| 222 | |
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| 223 | !!====================================================================== |
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| 224 | END MODULE zdfric |
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