| 1 | 
C $Header: /u/gcmpack/MITgcm/pkg/generic_advdiff/gad_diff_x.F,v 1.3 2001/09/21 13:11:43 adcroft Exp $ | 
| 2 | 
C $Name:  $ | 
| 3 | 
 | 
| 4 | 
#include "GAD_OPTIONS.h" | 
| 5 | 
 | 
| 6 | 
CBOP | 
| 7 | 
C !ROUTINE: GAD_DIFF_X | 
| 8 | 
 | 
| 9 | 
C !INTERFACE: ========================================================== | 
| 10 | 
      SUBROUTINE GAD_DIFF_X(  | 
| 11 | 
     I           bi,bj,k, | 
| 12 | 
     I           xA, diffKh, | 
| 13 | 
     I           tracer, | 
| 14 | 
     O           dfx, | 
| 15 | 
     I           myThid ) | 
| 16 | 
 | 
| 17 | 
C !DESCRIPTION: | 
| 18 | 
C Calculates the area integrated zonal flux due to down-gradient diffusion | 
| 19 | 
C of a tracer: | 
| 20 | 
C \begin{equation*} | 
| 21 | 
C F^x_{diff} = - A^x \kappa_h \frac{1}{\Delta x_c} \delta_i \theta | 
| 22 | 
C \end{equation*} | 
| 23 | 
 | 
| 24 | 
C !USES: =============================================================== | 
| 25 | 
      IMPLICIT NONE | 
| 26 | 
#include "SIZE.h" | 
| 27 | 
#include "GRID.h" | 
| 28 | 
 | 
| 29 | 
C !INPUT PARAMETERS: =================================================== | 
| 30 | 
C  bi,bj                :: tile indices | 
| 31 | 
C  k                    :: vertical level | 
| 32 | 
C  xA                   :: area of face at U points | 
| 33 | 
C  diffKh               :: horizontal diffusivity | 
| 34 | 
C  tracer               :: tracer field | 
| 35 | 
C  myThid               :: thread number | 
| 36 | 
      INTEGER bi,bj,k | 
| 37 | 
      _RS xA    (1-OLx:sNx+OLx,1-OLy:sNy+OLy) | 
| 38 | 
      _RL diffKh (1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr) | 
| 39 | 
      _RL tracer(1-OLx:sNx+OLx,1-OLy:sNy+OLy) | 
| 40 | 
      INTEGER myThid | 
| 41 | 
 | 
| 42 | 
C !OUTPUT PARAMETERS: ================================================== | 
| 43 | 
C  dfx                  :: zonal diffusive flux | 
| 44 | 
      _RL dfx   (1-OLx:sNx+OLx,1-OLy:sNy+OLy) | 
| 45 | 
 | 
| 46 | 
C !LOCAL VARIABLES: ==================================================== | 
| 47 | 
C  i,j                  :: loop indices | 
| 48 | 
      INTEGER i,j | 
| 49 | 
CEOP | 
| 50 | 
 | 
| 51 | 
C       print *,'in gad_diff_x' | 
| 52 | 
      DO j=1-Oly,sNy+Oly | 
| 53 | 
       dfx(1-Olx,j)=0. | 
| 54 | 
       DO i=1-Olx+1,sNx+Olx | 
| 55 | 
        dfx(i,j) = -diffKh(i,j,k)*xA(i,j) | 
| 56 | 
     &      *_recip_dxC(i,j,bi,bj) | 
| 57 | 
     &      *(Tracer(i,j)-Tracer(i-1,j)) | 
| 58 | 
     &      *CosFacU(j,bi,bj) | 
| 59 | 
       ENDDO | 
| 60 | 
      ENDDO | 
| 61 | 
 | 
| 62 | 
      RETURN | 
| 63 | 
      END | 
| 64 | 
c---------------------------------------------------------- | 
| 65 | 
      SUBROUTINE CALC_MLD(bi,bj,diffkh3d_x,diffkh3d_y,myThid) | 
| 66 | 
      implicit none | 
| 67 | 
 | 
| 68 | 
#include "SIZE.h" | 
| 69 | 
#include "EEPARAMS.h" | 
| 70 | 
#include "PARAMS.h" | 
| 71 | 
#include "DYNVARS.h" | 
| 72 | 
#include "GRID.h" | 
| 73 | 
 | 
| 74 | 
      INTEGER bi,bj | 
| 75 | 
      _RL diffkh3d_x (1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr) | 
| 76 | 
      _RL diffkh3d_y (1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr) | 
| 77 | 
      INTEGER myThid | 
| 78 | 
 | 
| 79 | 
C !LOCAL VARIABLES: ==================================================== | 
| 80 | 
C  i,j                  :: loop indices | 
| 81 | 
      INTEGER i,j !,k | 
| 82 | 
c jrs next | 
| 83 | 
      _RL rhoK (1-OLx:sNx+OLx,1-OLy:sNy+OLy) | 
| 84 | 
      _RL Khplus,gradij,gradim1,gradjm1,calc_grad | 
| 85 | 
C      _RL dep_frac | 
| 86 | 
      real *8 khconst,khmin,khmax | 
| 87 | 
      parameter ( khconst=5.d15 ) !2.5d15 | 
| 88 | 
      parameter ( khmin=1000.0 ) | 
| 89 | 
      parameter ( khmax=40000.0 ) !15000.0 | 
| 90 | 
cjrs try constants 6e14, 3e15, 5e15, 10e15 | 
| 91 | 
 | 
| 92 | 
c jrs next | 
| 93 | 
C       print *,'in calc_mld for Khplus ' | 
| 94 | 
Cold      CALL FIND_RHO( | 
| 95 | 
C     &     bi,bj,1-Olx,sNx+OLx,1-OLy,sNy+OLy,1,1, | 
| 96 | 
C     &     theta,salt,rhoK,myThid) | 
| 97 | 
      CALL FIND_RHO_2D( | 
| 98 | 
     &     1-Olx,sNx+OLx,1-OLy,sNy+OLy,1, | 
| 99 | 
     &     theta(1-OLx,1-OLy,1,bi,bj), salt(1-OLx,1-OLy,1,bi,bj), | 
| 100 | 
     &     rhoK, 1, bi, bj, myThid) | 
| 101 | 
 | 
| 102 | 
      DO j=1-Oly,sNy+Oly | 
| 103 | 
       DO i=1-Olx+1,sNx+Olx | 
| 104 | 
 | 
| 105 | 
 | 
| 106 | 
        if (hfacc(i,j,1,bi,bj).ne.0) then | 
| 107 | 
          gradij= calc_grad(i,j,bi,bj,rhoK) | 
| 108 | 
        endif | 
| 109 | 
 | 
| 110 | 
        if ( (hfacc(i,j,1,bi,bj).ne.0).and. | 
| 111 | 
     &       (hfacc(i-1,j,1,bi,bj).ne.0) ) then | 
| 112 | 
          gradim1= 0.! calc_grad(i-1,j,bi,bj,rhoK) | 
| 113 | 
          if ((gradij.ne.0).and.(gradim1.ne.0)) then | 
| 114 | 
            Khplus= khconst*(gradij+gradim1)/2 | 
| 115 | 
          elseif (gradij.ne.0) then | 
| 116 | 
            Khplus= khconst*gradij | 
| 117 | 
          elseif (gradim1.ne.0) then | 
| 118 | 
            Khplus= khconst*gradim1 | 
| 119 | 
          else | 
| 120 | 
            Khplus=0.d0 | 
| 121 | 
          endif | 
| 122 | 
          if (Khplus.lt.khmin) Khplus=khmin | 
| 123 | 
          if (Khplus.gt.khmax) Khplus=khmax | 
| 124 | 
          if (yC(i,j,bi,bj) .GE. 80.) Khplus=khmin | 
| 125 | 
          diffkh3d_x(i,j,1)=Khplus | 
| 126 | 
C          print *,'Khplus_x: ',i,j,Khplus | 
| 127 | 
 | 
| 128 | 
        else | 
| 129 | 
           diffkh3d_x(i,j,1)=0.d0 | 
| 130 | 
        endif | 
| 131 | 
 | 
| 132 | 
        if ( (hfacc(i,j,1,bi,bj).ne.0).and. | 
| 133 | 
     &       (hfacc(i,j-1,1,bi,bj).ne.0) ) then | 
| 134 | 
          gradjm1=0.!calc_grad(i,j-1,bi,bj,rhoK) | 
| 135 | 
          if ((gradij.ne.0).and.(gradjm1.ne.0)) then | 
| 136 | 
            Khplus= khconst*(gradij+gradjm1)/2 | 
| 137 | 
          elseif (gradij.ne.0) then | 
| 138 | 
            Khplus= khconst*gradij | 
| 139 | 
          elseif (gradjm1.ne.0) then | 
| 140 | 
            Khplus= khconst*gradjm1 | 
| 141 | 
          else | 
| 142 | 
            Khplus=0.d0 | 
| 143 | 
          endif | 
| 144 | 
          if (Khplus.lt.khmin) Khplus=khmin | 
| 145 | 
          if (Khplus.gt.khmax) Khplus=khmax | 
| 146 | 
          if (yC(i,j,bi,bj).GE. 80.) Khplus=khmin | 
| 147 | 
          diffkh3d_y(i,j,1)=Khplus | 
| 148 | 
c          diffkh3d_y(i,j,2)=0.5*Khplus | 
| 149 | 
c          diffkh3d_y(i,j,3)=0.2*Khplus | 
| 150 | 
C          print *,'Khplus_y: ',i,j,Khplus | 
| 151 | 
 | 
| 152 | 
        else | 
| 153 | 
           diffkh3d_y(i,j,1)=0.d0 | 
| 154 | 
        endif | 
| 155 | 
c        DO k=2,7 | 
| 156 | 
c          if (-hMixLayer(i,j,bi,bj).ge.rF(k)) then | 
| 157 | 
c             diffkh3d_x(i,j,k)=0.d0 | 
| 158 | 
c             diffkh3d_y(i,j,k)=0.d0 | 
| 159 | 
c          elseif (-hMixLayer(i,j,bi,bj).ge.rF(k+1)) then | 
| 160 | 
c             dep_frac=(hMixLayer(i,j,bi,bj)+rF(k))/drF(k)* | 
| 161 | 
c     &                (240.+rC(k))/240. | 
| 162 | 
c             diffkh3d_x(i,j,k)= dep_frac*diffkh3d_x(i,j,1) | 
| 163 | 
c             diffkh3d_y(i,j,k)= dep_frac*diffkh3d_y(i,j,1) | 
| 164 | 
c          else | 
| 165 | 
c             dep_frac = (240.+rC(k))/240. | 
| 166 | 
c             diffkh3d_x(i,j,k)= dep_frac*diffkh3d_x(i,j,1) | 
| 167 | 
c             diffkh3d_y(i,j,k)= dep_frac*diffkh3d_y(i,j,1) | 
| 168 | 
c          endif | 
| 169 | 
c        ENDDO | 
| 170 | 
 | 
| 171 | 
       ENDDO | 
| 172 | 
      ENDDO | 
| 173 | 
 | 
| 174 | 
      return | 
| 175 | 
      end | 
| 176 | 
c-------------------------------------------------- | 
| 177 | 
      real*8 FUNCTION CALC_GRAD(i,j,bi,bj,rhoK) | 
| 178 | 
      implicit none | 
| 179 | 
 | 
| 180 | 
#include "SIZE.h" | 
| 181 | 
#include "EEPARAMS.h" | 
| 182 | 
#include "PARAMS.h" | 
| 183 | 
#include "GRID.h" | 
| 184 | 
 | 
| 185 | 
      INTEGER i,j,bi,bj | 
| 186 | 
      _RL rhoK (1-OLx:sNx+OLx,1-OLy:sNy+OLy) | 
| 187 | 
 | 
| 188 | 
 | 
| 189 | 
c Local variables | 
| 190 | 
      integer xno,yno | 
| 191 | 
      _RL  xgrad,ygrad | 
| 192 | 
 | 
| 193 | 
c      print *,'entering calc_gradient...for ',i,j | 
| 194 | 
      if (hfacC(i,j,1,bi,bj).eq.0) then | 
| 195 | 
         calc_grad=0.d0 | 
| 196 | 
      else | 
| 197 | 
        xgrad=0.d0 | 
| 198 | 
        xno=0 | 
| 199 | 
        if (hfacC(i+1,j,1,bi,bj).ne.0) then | 
| 200 | 
          xgrad= abs((rhoK(i+1,j)-rhoK(i,j))*_recip_dxC(i+1,j,bi,bj)) | 
| 201 | 
          xno=1 | 
| 202 | 
c          print *,'gradient with i+1: ',xgrad | 
| 203 | 
        endif | 
| 204 | 
        if (hfacC(i-1,j,1,bi,bj).ne.0) then | 
| 205 | 
          xgrad= xgrad + | 
| 206 | 
     &          abs((rhoK(i,j)-rhoK(i-1,j))*_recip_dxC(i,j,bi,bj)) | 
| 207 | 
          xno=xno+1 | 
| 208 | 
c          print *,'gradient with i-1: ', | 
| 209 | 
c     &    abs((rhoK(i,j)-rhoK(i-1,j))*_recip_dxC(i,j,bi,bj)) | 
| 210 | 
        endif | 
| 211 | 
 | 
| 212 | 
        ygrad=0.d0 | 
| 213 | 
        yno=0 | 
| 214 | 
        if (hfacC(i,j+1,1,bi,bj).ne.0) then | 
| 215 | 
          ygrad= abs((rhoK(i,j+1)-rhoK(i,j))*_recip_dyC(i,j+1,bi,bj)) | 
| 216 | 
          yno=1 | 
| 217 | 
        endif | 
| 218 | 
        if (hfacC(i,j-1,1,bi,bj).ne.0) then | 
| 219 | 
          ygrad= ygrad + | 
| 220 | 
     &          abs((rhoK(i,j)-rhoK(i,j-1))*_recip_dyC(i,j,bi,bj)) | 
| 221 | 
          yno=yno+1 | 
| 222 | 
        endif | 
| 223 | 
 | 
| 224 | 
        if ((xno.ne.0).and.(yno.ne.0)) then | 
| 225 | 
          calc_grad=(xgrad/xno)*(xgrad/xno) + | 
| 226 | 
     &              (ygrad/yno)*(ygrad/yno) | 
| 227 | 
        elseif (xno.ne.0) then | 
| 228 | 
          calc_grad= (xgrad/xno)*(xgrad/xno) | 
| 229 | 
        else | 
| 230 | 
          calc_grad= (ygrad/yno)*(ygrad/yno) | 
| 231 | 
        endif | 
| 232 | 
      endif | 
| 233 | 
 | 
| 234 | 
      return | 
| 235 | 
      end |