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C $Header: /u/gcmpack/MITgcm/pkg/obcs/orlanski_west.F,v 1.3 2001/09/27 18:13:13 adcroft Exp $ |
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C $Name: $ |
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|
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#include "OBCS_OPTIONS.h" |
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|
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SUBROUTINE ORLANSKI_WEST( bi, bj, futureTime, |
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I uVel, vVel, wVel, theta, salt, |
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I myThid ) |
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C /==========================================================\ |
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C | SUBROUTINE ORLANSKI_WEST | |
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C | o Calculate future boundary data at open boundaries | |
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C | at time = futureTime by applying Orlanski radiation | |
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C | conditions. | |
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C |==========================================================| |
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C | | |
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C \==========================================================/ |
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IMPLICIT NONE |
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|
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C === Global variables === |
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#include "SIZE.h" |
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#include "EEPARAMS.h" |
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#include "PARAMS.h" |
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#include "GRID.h" |
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#include "OBCS.h" |
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#include "ORLANSKI.h" |
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|
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C SPK 6/2/00: Added radiative OBCs for salinity. |
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C SPK 6/6/00: Changed calculation of OB*w. When K=1, the |
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C upstream value is used. For example on the eastern OB: |
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C IF (K.EQ.1) THEN |
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C OBEw(J,K,bi,bj)=wVel(I_obc-1,J,K,bi,bj) |
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C ENDIF |
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C |
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C SPK 7/7/00: 1) Removed OB*w fix (see above). |
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C 2) Added variable CMAX. Maximum diagnosed phase speed is now |
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C clamped to CMAX. For stability of AB-II scheme (CFL) the |
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C (non-dimensional) phase speed must be <0.5 |
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C 3) (Sonya Legg) Changed application of uVel and vVel. |
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C uVel on the western OB is actually applied at I_obc+1 |
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C while vVel on the southern OB is applied at J_obc+1. |
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C 4) (Sonya Legg) Added templates for forced OBs. |
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C |
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C SPK 7/17/00: Non-uniform resolution is now taken into account in diagnosing |
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C phase speeds and time-stepping OB values. CL is still the |
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C non-dimensional phase speed; CVEL is the dimensional phase |
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C speed: CVEL = CL*(dx or dy)/dt, where dx and dy is the |
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C appropriate grid spacings. Note that CMAX (with which CL |
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C is compared) remains non-dimensional. |
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C |
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C SPK 7/18/00: Added code to allow filtering of phase speed following |
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C Blumberg and Kantha. There is now a separate array |
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C CVEL_**, where **=Variable(U,V,T,S,W)Boundary(E,W,N,S) for |
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C the dimensional phase speed. These arrays are initialized to |
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C zero in ini_obcs.F. CVEL_** is filtered according to |
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C CVEL_** = fracCVEL*CVEL(new) + (1-fracCVEL)*CVEL_**(old). |
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C fracCVEL=1.0 turns off filtering. |
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C |
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C SPK 7/26/00: Changed code to average phase speed. A new variable |
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C 'cvelTimeScale' was created. This variable must now be |
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C specified. Then, fracCVEL=deltaT/cvelTimeScale. |
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C Since the goal is to smooth out the 'singularities' in the |
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C diagnosed phase speed, cvelTimeScale could be picked as the |
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C duration of the singular period in the unfiltered case. Thus, |
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C for a plane wave cvelTimeScale might be the time take for the |
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C wave to travel a distance DX, where DX is the width of the region |
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C near which d(phi)/dx is small. |
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|
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C == Routine arguments == |
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INTEGER bi, bj |
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_RL futureTime |
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_RL uVel (1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr,nSx,nSy) |
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_RL vVel (1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr,nSx,nSy) |
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_RL wVel (1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr,nSx,nSy) |
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_RL theta(1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr,nSx,nSy) |
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_RL salt (1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr,nSx,nSy) |
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INTEGER myThid |
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|
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#ifdef ALLOW_ORLANSKI |
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|
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C == Local variables == |
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INTEGER J, K, I_obc |
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_RL CL, ab1, ab2, fracCVEL, f1, f2 |
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|
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ab1 = 1.5 _d 0 + abEps /* Adams-Bashforth coefficients */ |
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ab2 = -0.5 _d 0 - abEps |
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/* CMAX is maximum allowable phase speed-CFL for AB-II */ |
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/* cvelTimeScale is averaging period for phase speed in sec. */ |
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|
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fracCVEL = deltaT/cvelTimeScale /* fraction of new phase speed used*/ |
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f1 = fracCVEL /* dont change this. Set cvelTimeScale */ |
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f2 = 1.0-fracCVEL /* dont change this. set cvelTimeScale */ |
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|
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C Western OB (Orlanski Radiation Condition) |
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DO K=1,Nr |
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DO J=1-Oly,sNy+Oly |
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I_obc=OB_Iw(J,bi,bj) |
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IF (I_obc.ne.0) THEN |
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C uVel (to be applied at I_obc+1) |
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IF ((UW_STORE_2(J,K,bi,bj).eq.0.).and. |
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& (UW_STORE_3(J,K,bi,bj).eq.0.)) THEN |
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CL=0. |
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ELSE |
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CL=(uVel(I_obc+2,J,K,bi,bj)-UW_STORE_1(J,K,bi,bj))/ |
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& (ab1*UW_STORE_2(J,K,bi,bj) + ab2*UW_STORE_3(J,K,bi,bj)) |
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ENDIF |
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IF (CL.lt.0.) THEN |
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CL=0. |
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ELSEIF (CL.gt.CMAX) THEN |
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CL=CMAX |
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ENDIF |
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CVEL_UW(J,K,bi,bj) = f1*(CL*dxF(I_obc+2,J,bi,bj)/deltaT)+ |
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& f2*CVEL_UW(J,K,bi,bj) |
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C update OBC to next timestep |
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OBWu(J,K,bi,bj)=uVel(I_obc+1,J,K,bi,bj)+ |
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& CVEL_UW(J,K,bi,bj)*deltaT*recip_dxF(I_obc+1,J,bi,bj)* |
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& (ab1*(uVel(I_obc+2,J,K,bi,bj)-uVel(I_obc+1,J,K,bi,bj))+ |
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& ab2*(UW_STORE_1(J,K,bi,bj)-UW_STORE_4(J,K,bi,bj))) |
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C vVel |
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IF ((VW_STORE_2(J,K,bi,bj).eq.0.).and. |
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& (VW_STORE_3(J,K,bi,bj).eq.0.)) THEN |
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CL=0. |
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ELSE |
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CL=(vVel(I_obc+1,J,K,bi,bj)-VW_STORE_1(J,K,bi,bj))/ |
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& (ab1*VW_STORE_2(J,K,bi,bj) + ab2*VW_STORE_3(J,K,bi,bj)) |
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ENDIF |
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IF (CL.lt.0.) THEN |
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CL=0. |
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ELSEIF (CL.gt.CMAX) THEN |
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CL=CMAX |
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ENDIF |
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CVEL_VW(J,K,bi,bj) = f1*(CL*dxV(I_obc+2,J,bi,bj)/deltaT)+ |
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& f2*CVEL_VW(J,K,bi,bj) |
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C update OBC to next timestep |
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OBWv(J,K,bi,bj)=vVel(I_obc,J,K,bi,bj)+ |
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& CVEL_VW(J,K,bi,bj)*deltaT*recip_dxV(I_obc+1,J,bi,bj)* |
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& (ab1*(vVel(I_obc+1,J,K,bi,bj)-vVel(I_obc,J,K,bi,bj))+ |
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& ab2*(VW_STORE_1(J,K,bi,bj)-VW_STORE_4(J,K,bi,bj))) |
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C Temperature |
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IF ((TW_STORE_2(J,K,bi,bj).eq.0.).and. |
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& (TW_STORE_3(J,K,bi,bj).eq.0.)) THEN |
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CL=0. |
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ELSE |
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CL=(theta(I_obc+1,J,K,bi,bj)-TW_STORE_1(J,K,bi,bj))/ |
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& (ab1*TW_STORE_2(J,K,bi,bj) + ab2*TW_STORE_3(J,K,bi,bj)) |
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ENDIF |
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IF (CL.lt.0.) THEN |
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CL=0. |
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ELSEIF (CL.gt.CMAX) THEN |
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CL=CMAX |
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ENDIF |
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CVEL_TW(J,K,bi,bj) = f1*(CL*dxC(I_obc+2,J,bi,bj)/deltaT)+ |
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& f2*CVEL_TW(J,K,bi,bj) |
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C update OBC to next timestep |
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OBWt(J,K,bi,bj)=theta(I_obc,J,K,bi,bj)+ |
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& CVEL_TW(J,K,bi,bj)*deltaT*recip_dxC(I_obc+1,J,bi,bj)* |
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& (ab1*(theta(I_obc+1,J,K,bi,bj)-theta(I_obc,J,K,bi,bj))+ |
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& ab2*(TW_STORE_1(J,K,bi,bj)-TW_STORE_4(J,K,bi,bj))) |
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C Salinity |
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IF ((SW_STORE_2(J,K,bi,bj).eq.0.).and. |
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& (SW_STORE_3(J,K,bi,bj).eq.0.)) THEN |
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CL=0. |
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ELSE |
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CL=(salt(I_obc+1,J,K,bi,bj)-SW_STORE_1(J,K,bi,bj))/ |
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& (ab1*SW_STORE_2(J,K,bi,bj) + ab2*SW_STORE_3(J,K,bi,bj)) |
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ENDIF |
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IF (CL.lt.0.) THEN |
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CL=0. |
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ELSEIF (CL.gt.CMAX) THEN |
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CL=CMAX |
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ENDIF |
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CVEL_SW(J,K,bi,bj) = f1*(CL*dxC(I_obc+2,J,bi,bj)/deltaT)+ |
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& f2*CVEL_SW(J,K,bi,bj) |
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C update OBC to next timestep |
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OBWs(J,K,bi,bj)=salt(I_obc,J,K,bi,bj)+ |
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& CVEL_SW(J,K,bi,bj)*deltaT*recip_dxC(I_obc+1,J,bi,bj)* |
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& (ab1*(salt(I_obc+1,J,K,bi,bj)-salt(I_obc,J,K,bi,bj))+ |
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& ab2*(SW_STORE_1(J,K,bi,bj)-SW_STORE_4(J,K,bi,bj))) |
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C wVel |
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#ifdef ALLOW_NONHYDROSTATIC |
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IF ((WW_STORE_2(J,K,bi,bj).eq.0.).and. |
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& (WW_STORE_3(J,K,bi,bj).eq.0.)) THEN |
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CL=0. |
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ELSE |
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CL=(wVel(I_obc+1,J,K,bi,bj)-WW_STORE_1(J,K,bi,bj))/ |
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& (ab1*WW_STORE_2(J,K,bi,bj)+ab2*WW_STORE_3(J,K,bi,bj)) |
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ENDIF |
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IF (CL.lt.0.) THEN |
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CL=0. |
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ELSEIF (CL.gt.CMAX) THEN |
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CL=CMAX |
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ENDIF |
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CVEL_WW(J,K,bi,bj)=f1*(CL*dxC(I_obc+2,J,bi,bj)/deltaT) |
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& + f2*CVEL_WW(J,K,bi,bj) |
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C update OBC to next timestep |
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OBWw(J,K,bi,bj)=wVel(I_obc,J,K,bi,bj)+ |
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& CVEL_WW(J,K,bi,bj)*deltaT*recip_dxC(I_obc+1,J,bi,bj)* |
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& (ab1*(wVel(I_obc+1,J,K,bi,bj)-wVel(I_obc,J,K,bi,bj))+ |
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& ab2*(WW_STORE_1(J,K,bi,bj)-WW_STORE_4(J,K,bi,bj))) |
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#endif |
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C update/save storage arrays |
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C uVel |
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C copy t-1 to t-2 array |
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UW_STORE_3(J,K,bi,bj)=UW_STORE_2(J,K,bi,bj) |
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C copy (current time) t to t-1 arrays |
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UW_STORE_2(J,K,bi,bj)=uVel(I_obc+3,J,K,bi,bj) - |
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& uVel(I_obc+2,J,K,bi,bj) |
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UW_STORE_1(J,K,bi,bj)=uVel(I_obc+2,J,K,bi,bj) |
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UW_STORE_4(J,K,bi,bj)=uVel(I_obc+1,J,K,bi,bj) |
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C vVel |
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C copy t-1 to t-2 array |
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VW_STORE_3(J,K,bi,bj)=VW_STORE_2(J,K,bi,bj) |
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C copy (current time) t to t-1 arrays |
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VW_STORE_2(J,K,bi,bj)=vVel(I_obc+2,J,K,bi,bj) - |
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& vVel(I_obc+1,J,K,bi,bj) |
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VW_STORE_1(J,K,bi,bj)=vVel(I_obc+1,J,K,bi,bj) |
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VW_STORE_4(J,K,bi,bj)=vVel(I_obc,J,K,bi,bj) |
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C Temperature |
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C copy t-1 to t-2 array |
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TW_STORE_3(J,K,bi,bj)=TW_STORE_2(J,K,bi,bj) |
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C copy (current time) t to t-1 arrays |
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TW_STORE_2(J,K,bi,bj)=theta(I_obc+2,J,K,bi,bj) - |
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& theta(I_obc+1,J,K,bi,bj) |
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TW_STORE_1(J,K,bi,bj)=theta(I_obc+1,J,K,bi,bj) |
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TW_STORE_4(J,K,bi,bj)=theta(I_obc,J,K,bi,bj) |
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C wVel |
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#ifdef ALLOW_NONHYDROSTATIC |
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C copy t-1 to t-2 array |
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WW_STORE_3(J,K,bi,bj)=WW_STORE_2(J,K,bi,bj) |
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C copy (current time) t to t-1 arrays |
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WW_STORE_2(J,K,bi,bj)=wVel(I_obc+2,J,K,bi,bj) - |
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& wVel(I_obc+1,J,K,bi,bj) |
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WW_STORE_1(J,K,bi,bj)=wVel(I_obc+1,J,K,bi,bj) |
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WW_STORE_4(J,K,bi,bj)=wVel(I_obc,J,K,bi,bj) |
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#endif |
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ENDIF |
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ENDDO |
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ENDDO |
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|
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#endif /* ALLOW_ORLANSKI */ |
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RETURN |
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END |