[3] | 1 | MODULE zdfddm |
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| 2 | !!====================================================================== |
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| 3 | !! *** MODULE zdfddm *** |
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| 4 | !! Ocean physics : double diffusion mixing parameterization |
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| 5 | !!====================================================================== |
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| 6 | #if defined key_zdfddm || defined key_esopa |
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| 7 | !!---------------------------------------------------------------------- |
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| 8 | !! 'key_zdfddm' : double diffusion |
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| 9 | !!---------------------------------------------------------------------- |
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| 10 | !! zdf_ddm : compute the Ks for salinity |
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| 11 | !! zdf_ddm_init : read namelist and control the parameters |
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| 12 | !!---------------------------------------------------------------------- |
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| 13 | !! * Modules used |
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| 14 | USE oce ! ocean dynamics and tracers variables |
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| 15 | USE dom_oce ! ocean space and time domain variables |
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| 16 | USE zdf_oce ! ocean vertical physics variables |
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| 17 | USE in_out_manager ! I/O manager |
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| 18 | USE lbclnk ! ocean lateral boundary conditions (or mpp link) |
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[258] | 19 | USE prtctl ! Print control |
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[3] | 20 | |
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| 21 | IMPLICIT NONE |
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| 22 | PRIVATE |
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| 23 | |
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| 24 | !! * Routine accessibility |
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| 25 | PUBLIC zdf_ddm ! called by step.F90 |
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| 26 | |
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| 27 | !! * Shared module variables |
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[16] | 28 | LOGICAL, PUBLIC, PARAMETER :: lk_zdfddm = .TRUE. !: double diffusive mixing flag |
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| 29 | REAL(wp), PUBLIC, DIMENSION(jpi,jpj,jpk) :: & !: |
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[3] | 30 | avs , & !: salinity vertical diffusivity coeff. at w-point |
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| 31 | rrau !: heat/salt buoyancy flux ratio |
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| 32 | |
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| 33 | !! * Module variables |
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| 34 | REAL(wp) :: & !!! * double diffusive mixing namelist * |
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| 35 | avts = 1.e-4_wp , & ! maximum value of avs for salt fingering |
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| 36 | hsbfr = 1.6_wp ! heat/salt buoyancy flux ratio |
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| 37 | |
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| 38 | !! * Substitutions |
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| 39 | # include "vectopt_loop_substitute.h90" |
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| 40 | !!---------------------------------------------------------------------- |
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[247] | 41 | !! OPA 9.0 , LOCEAN-IPSL (2005) |
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[1152] | 42 | !! $Id$ |
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[247] | 43 | !! This software is governed by the CeCILL licence see modipsl/doc/NEMO_CeCILL.txt |
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[3] | 44 | !!---------------------------------------------------------------------- |
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| 45 | |
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| 46 | CONTAINS |
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| 47 | |
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| 48 | SUBROUTINE zdf_ddm( kt ) |
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| 49 | !!---------------------------------------------------------------------- |
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| 50 | !! *** ROUTINE zdf_ddm *** |
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| 51 | !! |
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| 52 | !! ** Purpose : Add to the vertical eddy diffusivity coefficient the |
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| 53 | !! effect of salt fingering and diffusive convection. |
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| 54 | !! |
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| 55 | !! ** Method : Diapycnal mixing is increased in case of double |
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| 56 | !! diffusive mixing (i.e. salt fingering and diffusive layering) |
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| 57 | !! following Merryfield et al. (1999). The rate of double diffusive |
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| 58 | !! mixing depend on the buoyancy ratio: Rrau=alpha/beta dk[T]/dk[S] |
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| 59 | !! which is computed in rn2.F |
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| 60 | !! * salt fingering (Schmitt 1981): |
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| 61 | !! for Rrau > 1 and rn2 > 0 : zavfs = avts / ( 1 + (Rrau/hsbfr)^6 ) |
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| 62 | !! for Rrau > 1 and rn2 > 0 : zavfs = O |
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| 63 | !! otherwise : zavft = 0.7 zavs / Rrau |
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| 64 | !! * diffusive layering (Federov 1988): |
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| 65 | !! for 0< Rrau < 1 and rn2 > 0 : zavdt = 1.3635e-6 |
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| 66 | !! * exp( 4.6 exp(-0.54 (1/Rrau-1) ) ) |
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| 67 | !! otherwise : zavdt = 0 |
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| 68 | !! for .5 < Rrau < 1 and rn2 > 0 : zavds = zavdt (1.885 Rrau -0.85) |
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| 69 | !! for 0 < Rrau <.5 and rn2 > 0 : zavds = zavdt 0.15 Rrau |
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| 70 | !! otherwise : zavds = 0 |
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| 71 | !! * update the eddy diffusivity: |
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| 72 | !! avt = avt + zavft + zavdt |
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| 73 | !! avs = avs + zavfs + zavds |
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| 74 | !! avmu, avmv are required to remain at least above avt and avs. |
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| 75 | !! |
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| 76 | !! ** Action : avt, avs : update vertical eddy diffusivity coef. |
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| 77 | !! for temperature and salinity |
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| 78 | !! |
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| 79 | !! References : |
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| 80 | !! Merryfield et al., JPO, 29, 1124-1142, 1999. |
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| 81 | !! History : |
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| 82 | !! ! 00-08 (G. Madec) double diffusive mixing |
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| 83 | !! 8.5 ! 02-06 (G. Madec) F90: Free form and module |
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| 84 | !!---------------------------------------------------------------------- |
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| 85 | !! * Arguments |
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| 86 | INTEGER, INTENT( in ) :: kt ! ocean time-step indexocean time step |
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| 87 | |
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| 88 | !! * Local declarations |
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| 89 | INTEGER :: ji, jj , jk ! dummy loop indices |
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| 90 | REAL(wp), DIMENSION(jpi,jpj) :: & |
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| 91 | zmsks, zmskf, & ! temporary workspace |
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| 92 | zmskd1, zmskd2, zmskd3 ! " " |
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| 93 | REAL(wp) :: & |
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| 94 | zinr, zrr, & ! temporary scalars |
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| 95 | zavft, zavfs, & ! " " |
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| 96 | zavdt, zavds ! " " |
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| 97 | !!---------------------------------------------------------------------- |
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| 98 | |
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| 99 | |
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| 100 | IF ( kt == nit000 ) CALL zdf_ddm_init ! Initialization (first time-step only) |
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| 101 | |
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| 102 | |
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| 103 | ! Compute avs |
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| 104 | ! ----------- |
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| 105 | ! ! =============== |
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| 106 | DO jk = 2, jpkm1 ! Horizontal slab |
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| 107 | ! ! =============== |
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| 108 | ! Define the mask |
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| 109 | ! --------------- |
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| 110 | ! only retains positive value of rrau |
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| 111 | rrau(:,:,jk) = MAX( 1.e-20, rrau(:,:,jk) ) |
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| 112 | |
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| 113 | ! indicators: |
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| 114 | DO jj = 1, jpj |
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| 115 | DO ji = 1, jpi |
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| 116 | ! stability indicator: msks=1 if rn2>0; 0 elsewhere |
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| 117 | IF( rn2(ji,jj,jk) + 1.e-12 <= 0. ) THEN |
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| 118 | zmsks(ji,jj) = 0.e0 |
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| 119 | ELSE |
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| 120 | zmsks(ji,jj) = 1.e0 |
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| 121 | ENDIF |
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| 122 | ! salt fingering indicator: msksf=1 if rrau>1; 0 elsewhere |
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| 123 | IF( rrau(ji,jj,jk) <= 1. ) THEN |
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| 124 | zmskf(ji,jj) = 0.e0 |
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| 125 | ELSE |
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| 126 | zmskf(ji,jj) = 1.e0 |
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| 127 | ENDIF |
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| 128 | ! diffusive layering indicators: |
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| 129 | ! mskdl1=1 if 0<rrau<1; 0 elsewhere |
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| 130 | IF( rrau(ji,jj,jk) >= 1. ) THEN |
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| 131 | zmskd1(ji,jj) = 0.e0 |
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| 132 | ELSE |
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| 133 | zmskd1(ji,jj) = 1.e0 |
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| 134 | ENDIF |
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| 135 | ! mskdl2=1 if 0<rrau<0.5; 0 elsewhere |
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| 136 | IF( rrau(ji,jj,jk) >= 0.5 ) THEN |
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| 137 | zmskd2(ji,jj) = 0.e0 |
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| 138 | ELSE |
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| 139 | zmskd2(ji,jj) = 1.e0 |
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| 140 | ENDIF |
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| 141 | ! mskdl3=1 if 0.5<rrau<1; 0 elsewhere |
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| 142 | IF( rrau(ji,jj,jk) <= 0.5 .OR. rrau(ji,jj,jk) >= 1. ) THEN |
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| 143 | zmskd3(ji,jj) = 0.e0 |
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| 144 | ELSE |
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| 145 | zmskd3(ji,jj) = 1.e0 |
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| 146 | ENDIF |
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| 147 | END DO |
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| 148 | END DO |
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| 149 | ! mask zmsk in order to have avt and avs masked |
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| 150 | zmsks(:,:) = zmsks(:,:) * tmask(:,:,jk) |
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| 151 | |
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| 152 | |
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| 153 | ! Update avt and avs |
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| 154 | ! ------------------ |
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| 155 | ! Constant eddy coefficient: reset to the background value |
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| 156 | !CDIR NOVERRCHK |
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| 157 | DO jj = 1, jpj |
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| 158 | !CDIR NOVERRCHK |
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| 159 | DO ji = 1, jpi |
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| 160 | zinr = 1./rrau(ji,jj,jk) |
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| 161 | ! salt fingering |
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| 162 | zrr = rrau(ji,jj,jk)/hsbfr |
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| 163 | zrr = zrr * zrr |
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| 164 | zavfs = avts / ( 1 + zrr*zrr*zrr ) * zmsks(ji,jj) *zmskf(ji,jj) |
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[1163] | 165 | zavft = 0.7 * zavfs * zinr |
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[3] | 166 | ! diffusive layering |
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| 167 | zavdt = 1.3635e-6 * EXP(4.6*EXP(-0.54*(zinr-1.) ) ) & |
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| 168 | * zmsks(ji,jj) * zmskd1(ji,jj) |
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| 169 | zavds = zavdt * zmsks(ji,jj) & |
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| 170 | * ( (1.85 * rrau(ji,jj,jk) - 0.85 ) * zmskd3(ji,jj) & |
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[1163] | 171 | + 0.15 * rrau(ji,jj,jk) * zmskd2(ji,jj) ) |
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[3] | 172 | ! add to the eddy viscosity coef. previously computed |
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| 173 | avs (ji,jj,jk) = avt(ji,jj,jk) + zavfs + zavds |
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| 174 | avt (ji,jj,jk) = avt(ji,jj,jk) + zavft + zavdt |
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[1527] | 175 | avm (ji,jj,jk) = avm(ji,jj,jk) + MAX( zavft + zavdt, zavfs + zavds ) |
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[3] | 176 | END DO |
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| 177 | END DO |
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| 178 | |
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| 179 | |
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| 180 | ! Increase avmu, avmv if necessary |
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| 181 | ! -------------------------------- |
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[1527] | 182 | !!gm to be changed following the definition of avm. |
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[3] | 183 | DO jj = 1, jpjm1 |
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| 184 | DO ji = 1, fs_jpim1 ! vector opt. |
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| 185 | avmu(ji,jj,jk) = MAX( avmu(ji,jj,jk), & |
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| 186 | avt(ji,jj,jk), avt(ji+1,jj,jk), & |
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| 187 | avs(ji,jj,jk), avs(ji+1,jj,jk) ) & |
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| 188 | * umask(ji,jj,jk) |
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| 189 | avmv(ji,jj,jk) = MAX( avmv(ji,jj,jk), & |
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| 190 | avt(ji,jj,jk), avt(ji,jj+1,jk), & |
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| 191 | avs(ji,jj,jk), avs(ji,jj+1,jk) ) & |
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| 192 | * vmask(ji,jj,jk) |
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| 193 | END DO |
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| 194 | END DO |
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| 195 | ! ! =============== |
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| 196 | END DO ! End of slab |
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| 197 | ! ! =============== |
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| 198 | |
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| 199 | ! Lateral boundary conditions on ( avt, avs, avmu, avmv ) (unchanged sign) |
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| 200 | ! -------------------------------======================== |
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| 201 | CALL lbc_lnk( avt , 'W', 1. ) |
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| 202 | CALL lbc_lnk( avs , 'W', 1. ) |
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[1527] | 203 | CALL lbc_lnk( avm , 'W', 1. ) |
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[3] | 204 | CALL lbc_lnk( avmu, 'U', 1. ) |
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| 205 | CALL lbc_lnk( avmv, 'V', 1. ) |
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[49] | 206 | |
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[258] | 207 | IF(ln_ctl) THEN |
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| 208 | CALL prt_ctl(tab3d_1=avt , clinfo1=' ddm - t: ', tab3d_2=avs , clinfo2=' s: ', ovlap=1, kdim=jpk) |
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[516] | 209 | CALL prt_ctl(tab3d_1=avmu, clinfo1=' ddm - u: ', mask1=umask, & |
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| 210 | & tab3d_2=avmv, clinfo2= ' v: ', mask2=vmask, ovlap=1, kdim=jpk) |
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[49] | 211 | ENDIF |
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[3] | 212 | |
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| 213 | END SUBROUTINE zdf_ddm |
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| 214 | |
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| 215 | |
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| 216 | SUBROUTINE zdf_ddm_init |
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| 217 | !!---------------------------------------------------------------------- |
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| 218 | !! *** ROUTINE zdf_ddm_init *** |
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| 219 | !! |
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| 220 | !! ** Purpose : Initialization of double diffusion mixing scheme |
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| 221 | !! |
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| 222 | !! ** Method : Read the nammbf namelist and check the parameter values |
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| 223 | !! called by zdf_ddm at the first timestep (nit000) |
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| 224 | !! |
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| 225 | !! History : |
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| 226 | !! 8.5 ! 02-08 (G. Madec) Original code |
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| 227 | !!---------------------------------------------------------------------- |
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| 228 | NAMELIST/namddm/ avts, hsbfr |
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| 229 | !!---------------------------------------------------------------------- |
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| 230 | |
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| 231 | ! Read Namelist namddm : double diffusion mixing scheme |
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| 232 | ! -------------------- |
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| 233 | REWIND ( numnam ) |
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| 234 | READ ( numnam, namddm ) |
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| 235 | |
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| 236 | |
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| 237 | ! Parameter control and print |
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| 238 | ! --------------------------- |
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| 239 | IF(lwp) THEN |
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| 240 | WRITE(numout,*) |
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| 241 | WRITE(numout,*) 'zdf_ddm : double diffusive mixing' |
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| 242 | WRITE(numout,*) '~~~~~~~' |
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| 243 | WRITE(numout,*) ' Namelist namddm : set dd mixing parameter' |
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| 244 | WRITE(numout,*) ' maximum avs for dd mixing avts = ', avts |
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| 245 | WRITE(numout,*) ' heat/salt buoyancy flux ratio hsbfr = ', hsbfr |
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| 246 | WRITE(numout,*) |
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| 247 | ENDIF |
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| 248 | |
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| 249 | END SUBROUTINE zdf_ddm_init |
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| 250 | |
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| 251 | #else |
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| 252 | !!---------------------------------------------------------------------- |
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| 253 | !! Default option : Dummy module No double diffusion |
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| 254 | !!---------------------------------------------------------------------- |
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[16] | 255 | LOGICAL, PUBLIC, PARAMETER :: lk_zdfddm = .FALSE. !: double diffusion flag |
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[3] | 256 | CONTAINS |
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| 257 | SUBROUTINE zdf_ddm( kt ) ! Dummy routine |
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[16] | 258 | WRITE(*,*) 'zdf_ddm: You should not have seen this print! error?', kt |
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[3] | 259 | END SUBROUTINE zdf_ddm |
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| 260 | #endif |
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| 261 | |
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| 262 | !!====================================================================== |
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| 263 | END MODULE zdfddm |
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