C $Header: /home/ubuntu/mnt/e9_copy/MITgcm/pkg/obcs/orlanski_west.F,v 1.7 2004/07/08 17:03:29 adcroft Exp $ C $Name: $ cc #include "OBCS_OPTIONS.h" SUBROUTINE ORLANSKI_WEST( bi, bj, futureTime, I uVel, vVel, wVel, theta, salt, I myThid ) C /==========================================================\ C | SUBROUTINE ORLANSKI_WEST | C | o Calculate future boundary data at open boundaries | C | at time = futureTime by applying Orlanski radiation | C | conditions. | C |==========================================================| C | | C \==========================================================/ IMPLICIT NONE C === Global variables === #include "SIZE.h" #include "EEPARAMS.h" #include "PARAMS.h" #include "GRID.h" #include "OBCS.h" #include "ORLANSKI.h" C SPK 6/2/00: Added radiative OBCs for salinity. C SPK 6/6/00: Changed calculation of OB*w. When K=1, the C upstream value is used. For example on the eastern OB: C IF (K.EQ.1) THEN C OBEw(J,K,bi,bj)=wVel(I_obc-1,J,K,bi,bj) C ENDIF C C SPK 7/7/00: 1) Removed OB*w fix (see above). C 2) Added variable CMAX. Maximum diagnosed phase speed is now C clamped to CMAX. For stability of AB-II scheme (CFL) the C (non-dimensional) phase speed must be <0.5 C 3) (Sonya Legg) Changed application of uVel and vVel. C uVel on the western OB is actually applied at I_obc+1 C while vVel on the southern OB is applied at J_obc+1. C 4) (Sonya Legg) Added templates for forced OBs. C C SPK 7/17/00: Non-uniform resolution is now taken into account in diagnosing C phase speeds and time-stepping OB values. CL is still the C non-dimensional phase speed; CVEL is the dimensional phase C speed: CVEL = CL*(dx or dy)/dt, where dx and dy is the C appropriate grid spacings. Note that CMAX (with which CL C is compared) remains non-dimensional. C C SPK 7/18/00: Added code to allow filtering of phase speed following C Blumberg and Kantha. There is now a separate array C CVEL_**, where **=Variable(U,V,T,S,W)Boundary(E,W,N,S) for C the dimensional phase speed. These arrays are initialized to C zero in ini_obcs.F. CVEL_** is filtered according to C CVEL_** = fracCVEL*CVEL(new) + (1-fracCVEL)*CVEL_**(old). C fracCVEL=1.0 turns off filtering. C C SPK 7/26/00: Changed code to average phase speed. A new variable C 'cvelTimeScale' was created. This variable must now be C specified. Then, fracCVEL=deltaT/cvelTimeScale. C Since the goal is to smooth out the 'singularities' in the C diagnosed phase speed, cvelTimeScale could be picked as the C duration of the singular period in the unfiltered case. Thus, C for a plane wave cvelTimeScale might be the time take for the C wave to travel a distance DX, where DX is the width of the region C near which d(phi)/dx is small. C C JBG 3/24/03: Fixed phase speed at western boundary (as suggested by C Dale Durran's MWR paper). Fixed value (in m/s) is C passed in as variable CFIX in data.obcs. C C JBG 4/10/03: allow choice of Orlanski or fixed wavespeed (by means of new C booleans useFixedCEast and useFixedCWest) without C having to recompile each time c SAL 1/7/03: Fixed bug: implementation for salinity was incomplete C C == Routine arguments == INTEGER bi, bj _RL futureTime _RL uVel (1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr,nSx,nSy) _RL vVel (1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr,nSx,nSy) _RL wVel (1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr,nSx,nSy) _RL theta(1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr,nSx,nSy) _RL salt (1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr,nSx,nSy) INTEGER myThid #ifdef ALLOW_ORLANSKI C == Local variables == INTEGER J, K, I_obc _RL CL, ab1, ab2, fracCVEL, f1, f2 ab1 = 1.5 _d 0 + abEps /* Adams-Bashforth coefficients */ ab2 = -0.5 _d 0 - abEps /* CMAX is maximum allowable phase speed-CFL for AB-II */ /* cvelTimeScale is averaging period for phase speed in sec. */ fracCVEL = deltaT/cvelTimeScale /* fraction of new phase speed used*/ f1 = fracCVEL /* dont change this. Set cvelTimeScale */ f2 = 1.0-fracCVEL /* dont change this. set cvelTimeScale */ C Western OB (Orlanski Radiation Condition) DO K=1,Nr DO J=1-Oly,sNy+Oly I_obc=OB_Iw(J,bi,bj) IF (I_obc.ne.0) THEN C uVel (to be applied at I_obc+1) IF ((UW_STORE_2(J,K,bi,bj).eq.0.).and. & (UW_STORE_3(J,K,bi,bj).eq.0.)) THEN CL=0. ELSE CL=(uVel(I_obc+2,J,K,bi,bj)-UW_STORE_1(J,K,bi,bj))/ & (ab1*UW_STORE_2(J,K,bi,bj) + ab2*UW_STORE_3(J,K,bi,bj)) ENDIF IF (CL.lt.0.) THEN CL=0. ELSEIF (CL.gt.CMAX) THEN CL=CMAX ENDIF IF (useFixedCWest) THEN C Fixed phase speed (ignoring all of that painstakingly C saved data...) CVEL_UW(J,K,bi,bj) = CFIX ELSE CVEL_UW(J,K,bi,bj) = f1*(CL*dxF(I_obc+2,J,bi,bj)/deltaT & )+f2*CVEL_UW(J,K,bi,bj) ENDIF C update OBC to next timestep OBWu(J,K,bi,bj)=uVel(I_obc+1,J,K,bi,bj)+ & CVEL_UW(J,K,bi,bj)*(deltaT*recip_dxF(I_obc+1,J,bi,bj))* & (ab1*(uVel(I_obc+2,J,K,bi,bj)-uVel(I_obc+1,J,K,bi,bj))+ & ab2*(UW_STORE_1(J,K,bi,bj)-UW_STORE_4(J,K,bi,bj))) C vVel IF ((VW_STORE_2(J,K,bi,bj).eq.0.).and. & (VW_STORE_3(J,K,bi,bj).eq.0.)) THEN CL=0. ELSE CL=(vVel(I_obc+1,J,K,bi,bj)-VW_STORE_1(J,K,bi,bj))/ & (ab1*VW_STORE_2(J,K,bi,bj) + ab2*VW_STORE_3(J,K,bi,bj)) ENDIF IF (CL.lt.0.) THEN CL=0. ELSEIF (CL.gt.CMAX) THEN CL=CMAX ENDIF IF (useFixedCWest) THEN C Fixed phase speed (ignoring all of that painstakingly C saved data...) CVEL_VW(J,K,bi,bj) = CFIX ELSE CVEL_VW(J,K,bi,bj) = f1*(CL*dxV(I_obc+2,J,bi,bj)/deltaT & )+f2*CVEL_VW(J,K,bi,bj) ENDIF C update OBC to next timestep OBWv(J,K,bi,bj)=vVel(I_obc,J,K,bi,bj)+ & CVEL_VW(J,K,bi,bj)*(deltaT*recip_dxV(I_obc+1,J,bi,bj))* & (ab1*(vVel(I_obc+1,J,K,bi,bj)-vVel(I_obc,J,K,bi,bj))+ & ab2*(VW_STORE_1(J,K,bi,bj)-VW_STORE_4(J,K,bi,bj))) C Temperature IF ((TW_STORE_2(J,K,bi,bj).eq.0.).and. & (TW_STORE_3(J,K,bi,bj).eq.0.)) THEN CL=0. ELSE CL=(theta(I_obc+1,J,K,bi,bj)-TW_STORE_1(J,K,bi,bj))/ & (ab1*TW_STORE_2(J,K,bi,bj) + ab2*TW_STORE_3(J,K,bi,bj)) ENDIF IF (CL.lt.0.) THEN CL=0. ELSEIF (CL.gt.CMAX) THEN CL=CMAX ENDIF IF (useFixedCWest) THEN C Fixed phase speed (ignoring all of that painstakingly C saved data...) CVEL_TW(J,K,bi,bj) = CFIX ELSE CVEL_TW(J,K,bi,bj) = f1*(CL*dxC(I_obc+2,J,bi,bj)/deltaT & )+f2*CVEL_TW(J,K,bi,bj) ENDIF C update OBC to next timestep OBWt(J,K,bi,bj)=theta(I_obc,J,K,bi,bj)+ & CVEL_TW(J,K,bi,bj)*(deltaT*recip_dxC(I_obc+1,J,bi,bj))* & (ab1*(theta(I_obc+1,J,K,bi,bj)-theta(I_obc,J,K,bi,bj))+ & ab2*(TW_STORE_1(J,K,bi,bj)-TW_STORE_4(J,K,bi,bj))) C Salinity IF ((SW_STORE_2(J,K,bi,bj).eq.0.).and. & (SW_STORE_3(J,K,bi,bj).eq.0.)) THEN CL=0. ELSE CL=(salt(I_obc+1,J,K,bi,bj)-SW_STORE_1(J,K,bi,bj))/ & (ab1*SW_STORE_2(J,K,bi,bj) + ab2*SW_STORE_3(J,K,bi,bj)) ENDIF IF (CL.lt.0.) THEN CL=0. ELSEIF (CL.gt.CMAX) THEN CL=CMAX ENDIF IF (useFixedCWest) THEN C Fixed phase speed (ignoring all of that painstakingly C saved data...) CVEL_SW(J,K,bi,bj) = CFIX ELSE CVEL_SW(J,K,bi,bj) = f1*(CL*dxC(I_obc+2,J,bi,bj)/deltaT & )+f2*CVEL_SW(J,K,bi,bj) ENDIF C update OBC to next timestep OBWs(J,K,bi,bj)=salt(I_obc,J,K,bi,bj)+ & CVEL_SW(J,K,bi,bj)*(deltaT*recip_dxC(I_obc+1,J,bi,bj))* & (ab1*(salt(I_obc+1,J,K,bi,bj)-salt(I_obc,J,K,bi,bj))+ & ab2*(SW_STORE_1(J,K,bi,bj)-SW_STORE_4(J,K,bi,bj))) C wVel #ifdef ALLOW_NONHYDROSTATIC IF ((WW_STORE_2(J,K,bi,bj).eq.0.).and. & (WW_STORE_3(J,K,bi,bj).eq.0.)) THEN CL=0. ELSE CL=(wVel(I_obc+1,J,K,bi,bj)-WW_STORE_1(J,K,bi,bj))/ & (ab1*WW_STORE_2(J,K,bi,bj)+ab2*WW_STORE_3(J,K,bi,bj)) ENDIF IF (CL.lt.0.) THEN CL=0. ELSEIF (CL.gt.CMAX) THEN CL=CMAX ENDIF IF (useFixedCWest) THEN C Fixed phase speed (ignoring all of that painstakingly C saved data...) CVEL_WW(J,K,bi,bj) = CFIX ELSE CVEL_WW(J,K,bi,bj)=f1*(CL*dxC(I_obc+2,J,bi,bj)/deltaT) & + f2*CVEL_WW(J,K,bi,bj) ENDIF C update OBC to next timestep OBWw(J,K,bi,bj)=wVel(I_obc,J,K,bi,bj)+ & CVEL_WW(J,K,bi,bj)*(deltaT*recip_dxC(I_obc+1,J,bi,bj))* & (ab1*(wVel(I_obc+1,J,K,bi,bj)-wVel(I_obc,J,K,bi,bj))+ & ab2*(WW_STORE_1(J,K,bi,bj)-WW_STORE_4(J,K,bi,bj))) #endif C update/save storage arrays C uVel C copy t-1 to t-2 array UW_STORE_3(J,K,bi,bj)=UW_STORE_2(J,K,bi,bj) C copy (current time) t to t-1 arrays UW_STORE_2(J,K,bi,bj)=uVel(I_obc+3,J,K,bi,bj) - & uVel(I_obc+2,J,K,bi,bj) UW_STORE_1(J,K,bi,bj)=uVel(I_obc+2,J,K,bi,bj) UW_STORE_4(J,K,bi,bj)=uVel(I_obc+1,J,K,bi,bj) C vVel C copy t-1 to t-2 array VW_STORE_3(J,K,bi,bj)=VW_STORE_2(J,K,bi,bj) C copy (current time) t to t-1 arrays VW_STORE_2(J,K,bi,bj)=vVel(I_obc+2,J,K,bi,bj) - & vVel(I_obc+1,J,K,bi,bj) VW_STORE_1(J,K,bi,bj)=vVel(I_obc+1,J,K,bi,bj) VW_STORE_4(J,K,bi,bj)=vVel(I_obc,J,K,bi,bj) C Temperature C copy t-1 to t-2 array TW_STORE_3(J,K,bi,bj)=TW_STORE_2(J,K,bi,bj) C copy (current time) t to t-1 arrays TW_STORE_2(J,K,bi,bj)=theta(I_obc+2,J,K,bi,bj) - & theta(I_obc+1,J,K,bi,bj) TW_STORE_1(J,K,bi,bj)=theta(I_obc+1,J,K,bi,bj) TW_STORE_4(J,K,bi,bj)=theta(I_obc,J,K,bi,bj) c Salinity C copy t-1 to t-2 array SW_STORE_3(J,K,bi,bj)=SW_STORE_2(J,K,bi,bj) C copy (current time) t to t-1 arrays SW_STORE_2(J,K,bi,bj)=salt(I_obc+2,J,K,bi,bj) - & salt(I_obc+1,J,K,bi,bj) SW_STORE_1(J,K,bi,bj)=salt(I_obc+1,J,K,bi,bj) SW_STORE_4(J,K,bi,bj)=salt(I_obc,J,K,bi,bj) C wVel #ifdef ALLOW_NONHYDROSTATIC C copy t-1 to t-2 array WW_STORE_3(J,K,bi,bj)=WW_STORE_2(J,K,bi,bj) C copy (current time) t to t-1 arrays WW_STORE_2(J,K,bi,bj)=wVel(I_obc+2,J,K,bi,bj) - & wVel(I_obc+1,J,K,bi,bj) WW_STORE_1(J,K,bi,bj)=wVel(I_obc+1,J,K,bi,bj) WW_STORE_4(J,K,bi,bj)=wVel(I_obc,J,K,bi,bj) #endif ENDIF ENDDO ENDDO #endif /* ALLOW_ORLANSKI */ RETURN END