MODULE zetabc_mod ! !git $Id$ !svn $Id: zetabc.F 1178 2023-07-11 17:50:57Z arango $ !================================================== Hernan G. Arango === ! Copyright (c) 2002-2023 The ROMS/TOMS Group ! ! Licensed under a MIT/X style license ! ! See License_ROMS.md ! !======================================================================= ! ! ! This routine sets lateral boundary conditions for free-surface. ! ! ! !======================================================================= ! USE mod_param USE mod_boundary USE mod_grid USE mod_ncparam USE mod_ocean USE mod_scalars USE mod_stepping ! implicit none ! PRIVATE PUBLIC :: zetabc_tile ! CONTAINS ! !*********************************************************************** SUBROUTINE zetabc (ng, tile, kout) !*********************************************************************** ! ! Imported variable declarations. ! integer, intent(in) :: ng, tile, kout ! ! Local variable declarations. ! integer :: IminS, ImaxS, JminS, JmaxS integer :: LBi, UBi, LBj, UBj, LBij, UBij ! ! Set horizontal starting and ending indices for automatic private ! storage arrays. ! IminS=BOUNDS(ng)%Istr(tile)-3 ImaxS=BOUNDS(ng)%Iend(tile)+3 JminS=BOUNDS(ng)%Jstr(tile)-3 JmaxS=BOUNDS(ng)%Jend(tile)+3 ! ! Determine array lower and upper bounds in the I- and J-directions. ! LBi=BOUNDS(ng)%LBi(tile) UBi=BOUNDS(ng)%UBi(tile) LBj=BOUNDS(ng)%LBj(tile) UBj=BOUNDS(ng)%UBj(tile) ! ! Set array lower and upper bounds for MIN(I,J) directions and ! MAX(I,J) directions. ! LBij=BOUNDS(ng)%LBij UBij=BOUNDS(ng)%UBij ! CALL zetabc_tile (ng, tile, & & LBi, UBi, LBj, UBj, & & IminS, ImaxS, JminS, JmaxS, & & krhs(ng), kstp(ng), kout, & & OCEAN(ng) % zeta) RETURN END SUBROUTINE zetabc ! !*********************************************************************** SUBROUTINE zetabc_tile (ng, tile, & & LBi, UBi, LBj, UBj, & & IminS, ImaxS, JminS, JmaxS, & & krhs, kstp, kout, & & zeta) !*********************************************************************** ! ! Imported variable declarations. ! integer, intent(in) :: ng, tile integer, intent(in) :: LBi, UBi, LBj, UBj integer, intent(in) :: IminS, ImaxS, JminS, JmaxS integer, intent(in) :: krhs, kstp, kout ! real(r8), intent(inout) :: zeta(LBi:,LBj:,:) ! ! Local variable declarations. ! integer :: i, j, know real(r8), parameter :: eps =1.0E-20_r8 real(r8) :: Ce, Cx real(r8) :: cff, cff1, cff2, dt2d, dZde, dZdt, dZdx, tau real(r8), dimension(IminS:ImaxS,JminS:JmaxS) :: grad ! !----------------------------------------------------------------------- ! Set lower and upper tile bounds and staggered variables bounds for ! this horizontal domain partition. Notice that if tile=-1, it will ! set the values for the global grid. !----------------------------------------------------------------------- ! integer :: Istr, IstrB, IstrP, IstrR, IstrT, IstrM, IstrU integer :: Iend, IendB, IendP, IendR, IendT integer :: Jstr, JstrB, JstrP, JstrR, JstrT, JstrM, JstrV integer :: Jend, JendB, JendP, JendR, JendT integer :: Istrm3, Istrm2, Istrm1, IstrUm2, IstrUm1 integer :: Iendp1, Iendp2, Iendp2i, Iendp3 integer :: Jstrm3, Jstrm2, Jstrm1, JstrVm2, JstrVm1 integer :: Jendp1, Jendp2, Jendp2i, Jendp3 ! Istr =BOUNDS(ng) % Istr (tile) IstrB =BOUNDS(ng) % IstrB (tile) IstrM =BOUNDS(ng) % IstrM (tile) IstrP =BOUNDS(ng) % IstrP (tile) IstrR =BOUNDS(ng) % IstrR (tile) IstrT =BOUNDS(ng) % IstrT (tile) IstrU =BOUNDS(ng) % IstrU (tile) Iend =BOUNDS(ng) % Iend (tile) IendB =BOUNDS(ng) % IendB (tile) IendP =BOUNDS(ng) % IendP (tile) IendR =BOUNDS(ng) % IendR (tile) IendT =BOUNDS(ng) % IendT (tile) Jstr =BOUNDS(ng) % Jstr (tile) JstrB =BOUNDS(ng) % JstrB (tile) JstrM =BOUNDS(ng) % JstrM (tile) JstrP =BOUNDS(ng) % JstrP (tile) JstrR =BOUNDS(ng) % JstrR (tile) JstrT =BOUNDS(ng) % JstrT (tile) JstrV =BOUNDS(ng) % JstrV (tile) Jend =BOUNDS(ng) % Jend (tile) JendB =BOUNDS(ng) % JendB (tile) JendP =BOUNDS(ng) % JendP (tile) JendR =BOUNDS(ng) % JendR (tile) JendT =BOUNDS(ng) % JendT (tile) ! Istrm3 =BOUNDS(ng) % Istrm3 (tile) ! Istr-3 Istrm2 =BOUNDS(ng) % Istrm2 (tile) ! Istr-2 Istrm1 =BOUNDS(ng) % Istrm1 (tile) ! Istr-1 IstrUm2=BOUNDS(ng) % IstrUm2(tile) ! IstrU-2 IstrUm1=BOUNDS(ng) % IstrUm1(tile) ! IstrU-1 Iendp1 =BOUNDS(ng) % Iendp1 (tile) ! Iend+1 Iendp2 =BOUNDS(ng) % Iendp2 (tile) ! Iend+2 Iendp2i=BOUNDS(ng) % Iendp2i(tile) ! Iend+2 interior Iendp3 =BOUNDS(ng) % Iendp3 (tile) ! Iend+3 Jstrm3 =BOUNDS(ng) % Jstrm3 (tile) ! Jstr-3 Jstrm2 =BOUNDS(ng) % Jstrm2 (tile) ! Jstr-2 Jstrm1 =BOUNDS(ng) % Jstrm1 (tile) ! Jstr-1 JstrVm2=BOUNDS(ng) % JstrVm2(tile) ! JstrV-2 JstrVm1=BOUNDS(ng) % JstrVm1(tile) ! JstrV-1 Jendp1 =BOUNDS(ng) % Jendp1 (tile) ! Jend+1 Jendp2 =BOUNDS(ng) % Jendp2 (tile) ! Jend+2 Jendp2i=BOUNDS(ng) % Jendp2i(tile) ! Jend+2 interior Jendp3 =BOUNDS(ng) % Jendp3 (tile) ! Jend+3 ! !----------------------------------------------------------------------- ! Set time-indices !----------------------------------------------------------------------- ! IF (iif(ng).eq.1) THEN know=krhs dt2d=dtfast(ng) ELSE IF (PREDICTOR_2D_STEP(ng)) THEN know=krhs dt2d=2.0_r8*dtfast(ng) ELSE know=kstp dt2d=dtfast(ng) END IF ! !----------------------------------------------------------------------- ! Lateral boundary conditions at the western edge. !----------------------------------------------------------------------- ! IF (DOMAIN(ng)%Western_Edge(tile)) THEN ! ! Western edge, implicit upstream radiation condition. ! IF (LBC(iwest,isFsur,ng)%radiation) THEN DO j=Jstr,Jend+1 grad(Istr-1,j)=zeta(Istr-1,j ,know)- & & zeta(Istr-1,j-1,know) grad(Istr-1,j)=grad(Istr-1,j)*GRID(ng)%vmask(Istr-1,j) grad(Istr,j)=zeta(Istr,j ,know)- & & zeta(Istr,j-1,know) grad(Istr,j)=grad(Istr,j)*GRID(ng)%vmask(Istr,j) END DO DO j=Jstr,Jend IF (LBC_apply(ng)%west(j)) THEN dZdt=zeta(Istr,j,know)-zeta(Istr ,j,kout) dZdx=zeta(Istr,j,kout)-zeta(Istr+1,j,kout) IF (LBC(iwest,isFsur,ng)%nudging) THEN IF ((dZdt*dZdx).lt.0.0_r8) THEN tau=FSobc_in(ng,iwest) ELSE tau=FSobc_out(ng,iwest) END IF tau=tau*dt2d END IF IF ((dZdt*dZdx).lt.0.0_r8) dZdt=0.0_r8 IF ((dZdt*(grad(Istr,j)+grad(Istr,j+1))).gt.0.0_r8) THEN dZde=grad(Istr,j ) ELSE dZde=grad(Istr,j+1) END IF cff=MAX(dZdx*dZdx+dZde*dZde,eps) Cx=dZdt*dZdx Ce=MIN(cff,MAX(dZdt*dZde,-cff)) zeta(Istr-1,j,kout)=(cff*zeta(Istr-1,j,know)+ & & Cx *zeta(Istr ,j,kout)- & & MAX(Ce,0.0_r8)*grad(Istr-1,j )- & & MIN(Ce,0.0_r8)*grad(Istr-1,j+1))/ & & (cff+Cx) IF (LBC(iwest,isFsur,ng)%nudging) THEN zeta(Istr-1,j,kout)=zeta(Istr-1,j,kout)+ & & tau*(BOUNDARY(ng)%zeta_west(j)- & & zeta(Istr-1,j,know)) END IF zeta(Istr-1,j,kout)=zeta(Istr-1,j,kout)* & & GRID(ng)%rmask(Istr-1,j) END IF END DO ! ! Western edge, explicit Chapman boundary condition. ! ELSE IF (LBC(iwest,isFsur,ng)%Chapman_explicit) THEN DO j=Jstr,Jend IF (LBC_apply(ng)%west(j)) THEN cff=dt2d*GRID(ng)%pm(Istr,j) cff1=SQRT(g*(GRID(ng)%h(Istr,j)+ & & zeta(Istr,j,know))) Cx=cff*cff1 zeta(Istr-1,j,kout)=(1.0_r8-Cx)*zeta(Istr-1,j,know)+ & & Cx*zeta(Istr,j,know) zeta(Istr-1,j,kout)=zeta(Istr-1,j,kout)* & & GRID(ng)%rmask(Istr-1,j) END IF END DO ! ! Western edge, implicit Chapman boundary condition. ! ELSE IF (LBC(iwest,isFsur,ng)%Chapman_implicit) THEN DO j=Jstr,Jend IF (LBC_apply(ng)%west(j)) THEN cff=dt2d*GRID(ng)%pm(Istr,j) cff1=SQRT(g*(GRID(ng)%h(Istr,j)+ & & zeta(Istr,j,know))) Cx=cff*cff1 cff2=1.0_r8/(1.0_r8+Cx) zeta(Istr-1,j,kout)=cff2*(zeta(Istr-1,j,know)+ & & Cx*zeta(Istr,j,kout)) zeta(Istr-1,j,kout)=zeta(Istr-1,j,kout)* & & GRID(ng)%rmask(Istr-1,j) END IF END DO ! ! Western edge, clamped boundary condition. ! ELSE IF (LBC(iwest,isFsur,ng)%clamped) THEN DO j=Jstr,Jend IF (LBC_apply(ng)%west(j)) THEN zeta(Istr-1,j,kout)=BOUNDARY(ng)%zeta_west(j) zeta(Istr-1,j,kout)=zeta(Istr-1,j,kout)* & & GRID(ng)%rmask(Istr-1,j) END IF END DO ! ! Western edge, gradient boundary condition. ! ELSE IF (LBC(iwest,isFsur,ng)%gradient) THEN DO j=Jstr,Jend IF (LBC_apply(ng)%west(j)) THEN zeta(Istr-1,j,kout)=zeta(Istr,j,kout) zeta(Istr-1,j,kout)=zeta(Istr-1,j,kout)* & & GRID(ng)%rmask(Istr-1,j) END IF END DO ! ! Western edge, closed boundary condition. ! ELSE IF (LBC(iwest,isFsur,ng)%closed) THEN DO j=Jstr,Jend IF (LBC_apply(ng)%west(j)) THEN zeta(Istr-1,j,kout)=zeta(Istr,j,kout) zeta(Istr-1,j,kout)=zeta(Istr-1,j,kout)* & & GRID(ng)%rmask(Istr-1,j) END IF END DO END IF END IF ! !----------------------------------------------------------------------- ! Lateral boundary conditions at the eastern edge. !----------------------------------------------------------------------- ! IF (DOMAIN(ng)%Eastern_Edge(tile)) THEN ! ! Eastern edge, implicit upstream radiation condition. ! IF (LBC(ieast,isFsur,ng)%radiation) THEN DO j=Jstr,Jend+1 grad(Iend ,j)=zeta(Iend ,j ,know)- & & zeta(Iend ,j-1,know) grad(Iend ,j)=grad(Iend ,j)*GRID(ng)%vmask(Iend ,j) grad(Iend+1,j)=zeta(Iend+1,j ,know)- & & zeta(Iend+1,j-1,know) grad(Iend+1,j)=grad(Iend+1,j)*GRID(ng)%vmask(Iend+1,j) END DO DO j=Jstr,Jend IF (LBC_apply(ng)%east(j)) THEN dZdt=zeta(Iend,j,know)-zeta(Iend ,j,kout) dZdx=zeta(Iend,j,kout)-zeta(Iend-1,j,kout) IF (LBC(ieast,isFsur,ng)%nudging) THEN IF ((dZdt*dZdx).lt.0.0_r8) THEN tau=FSobc_in(ng,ieast) ELSE tau=FSobc_out(ng,ieast) END IF tau=tau*dt2d END IF IF ((dZdt*dZdx).lt.0.0_r8) dZdt=0.0_r8 IF ((dZdt*(grad(Iend,j)+grad(Iend,j+1))).gt.0.0_r8) THEN dZde=grad(Iend,j ) ELSE dZde=grad(Iend,j+1) END IF cff=MAX(dZdx*dZdx+dZde*dZde,eps) Cx=dZdt*dZdx Ce=MIN(cff,MAX(dZdt*dZde,-cff)) zeta(Iend+1,j,kout)=(cff*zeta(Iend+1,j,know)+ & & Cx *zeta(Iend ,j,kout)- & & MAX(Ce,0.0_r8)*grad(Iend+1,j )- & & MIN(Ce,0.0_r8)*grad(Iend+1,j+1))/ & & (cff+Cx) IF (LBC(ieast,isFsur,ng)%nudging) THEN zeta(Iend+1,j,kout)=zeta(Iend+1,j,kout)+ & & tau*(BOUNDARY(ng)%zeta_east(j)- & & zeta(Iend+1,j,know)) END IF zeta(Iend+1,j,kout)=zeta(Iend+1,j,kout)* & & GRID(ng)%rmask(Iend+1,j) END IF END DO ! ! Eastern edge, explicit Chapman boundary condition. ! ELSE IF (LBC(ieast,isFsur,ng)%Chapman_explicit) THEN DO j=Jstr,Jend IF (LBC_apply(ng)%east(j)) THEN cff=dt2d*GRID(ng)%pm(Iend,j) cff1=SQRT(g*(GRID(ng)%h(Iend,j)+ & & zeta(Iend,j,know))) Cx=cff*cff1 zeta(Iend+1,j,kout)=(1.0_r8-Cx)*zeta(Iend+1,j,know)+ & & Cx*zeta(Iend,j,know) zeta(Iend+1,j,kout)=zeta(Iend+1,j,kout)* & & GRID(ng)%rmask(Iend+1,j) END IF END DO ! ! Eastern edge, implicit Chapman boundary condition. ! ELSE IF (LBC(ieast,isFsur,ng)%Chapman_implicit) THEN DO j=Jstr,Jend IF (LBC_apply(ng)%east(j)) THEN cff=dt2d*GRID(ng)%pm(Iend,j) cff1=SQRT(g*(GRID(ng)%h(Iend,j)+ & & zeta(Iend,j,know))) Cx=cff*cff1 cff2=1.0_r8/(1.0_r8+Cx) zeta(Iend+1,j,kout)=cff2*(zeta(Iend+1,j,know)+ & & Cx*zeta(Iend,j,kout)) zeta(Iend+1,j,kout)=zeta(Iend+1,j,kout)* & & GRID(ng)%rmask(Iend+1,j) END IF END DO ! ! Eastern edge, clamped boundary condition. ! ELSE IF (LBC(ieast,isFsur,ng)%clamped) THEN DO j=Jstr,Jend IF (LBC_apply(ng)%east(j)) THEN zeta(Iend+1,j,kout)=BOUNDARY(ng)%zeta_east(j) zeta(Iend+1,j,kout)=zeta(Iend+1,j,kout)* & & GRID(ng)%rmask(Iend+1,j) END IF END DO ! ! Eastern edge, gradient boundary condition. ! ELSE IF (LBC(ieast,isFsur,ng)%gradient) THEN DO j=Jstr,Jend IF (LBC_apply(ng)%east(j)) THEN zeta(Iend+1,j,kout)=zeta(Iend,j,kout) zeta(Iend+1,j,kout)=zeta(Iend+1,j,kout)* & & GRID(ng)%rmask(Iend+1,j) END IF END DO ! ! Eastern edge, closed boundary condition. ! ELSE IF (LBC(ieast,isFsur,ng)%closed) THEN DO j=Jstr,Jend IF (LBC_apply(ng)%east(j)) THEN zeta(Iend+1,j,kout)=zeta(Iend,j,kout) zeta(Iend+1,j,kout)=zeta(Iend+1,j,kout)* & & GRID(ng)%rmask(Iend+1,j) END IF END DO END IF END IF ! !----------------------------------------------------------------------- ! Lateral boundary conditions at the southern edge. !----------------------------------------------------------------------- ! IF (DOMAIN(ng)%Southern_Edge(tile)) THEN ! ! Southern edge, implicit upstream radiation condition. ! IF (LBC(isouth,isFsur,ng)%radiation) THEN DO i=Istr,Iend+1 grad(i,Jstr )=zeta(i ,Jstr,know)- & & zeta(i-1,Jstr,know) grad(i,Jstr )=grad(i,Jstr )*GRID(ng)%umask(i,Jstr ) grad(i,Jstr-1)=zeta(i ,Jstr-1,know)- & & zeta(i-1,Jstr-1,know) grad(i,Jstr-1)=grad(i,Jstr-1)*GRID(ng)%umask(i,Jstr-1) END DO DO i=Istr,Iend IF (LBC_apply(ng)%south(i)) THEN dZdt=zeta(i,Jstr,know)-zeta(i,Jstr ,kout) dZde=zeta(i,Jstr,kout)-zeta(i,Jstr-1,kout) IF (LBC(isouth,isFsur,ng)%nudging) THEN IF ((dZdt*dZde).lt.0.0_r8) THEN tau=FSobc_in(ng,isouth) ELSE tau=FSobc_out(ng,isouth) END IF tau=tau*dt2d END IF IF ((dZdt*dZde).lt.0.0_r8) dZdt=0.0_r8 IF ((dZdt*(grad(i,Jstr)+grad(i+1,Jstr))).gt.0.0_r8) THEN dZdx=grad(i ,Jstr) ELSE dZdx=grad(i+1,Jstr) END IF cff=MAX(dZdx*dZdx+dZde*dZde,eps) Cx=MIN(cff,MAX(dZdt*dZdx,-cff)) Ce=dZdt*dZde zeta(i,Jstr-1,kout)=(cff*zeta(i,Jstr-1,know)+ & & Ce *zeta(i,Jstr ,kout)- & & MAX(Cx,0.0_r8)*grad(i ,Jstr)- & & MIN(Cx,0.0_r8)*grad(i+1,Jstr))/ & & (cff+Ce) IF (LBC(isouth,isFsur,ng)%nudging) THEN zeta(i,Jstr-1,kout)=zeta(i,Jstr-1,kout)+ & & tau*(BOUNDARY(ng)%zeta_south(i)- & & zeta(i,Jstr-1,know)) END IF zeta(i,Jstr-1,kout)=zeta(i,Jstr-1,kout)* & & GRID(ng)%rmask(i,Jstr-1) END IF END DO ! ! Southern edge, explicit Chapman boundary condition. ! ELSE IF (LBC(isouth,isFsur,ng)%Chapman_explicit) THEN DO i=Istr,Iend IF (LBC_apply(ng)%south(i)) THEN cff=dt2d*GRID(ng)%pn(i,Jstr) cff1=SQRT(g*(GRID(ng)%h(i,Jstr)+ & & zeta(i,Jstr,know))) Ce=cff*cff1 zeta(i,Jstr-1,kout)=(1.0_r8-Ce)*zeta(i,Jstr-1,know)+ & & Ce*zeta(i,Jstr,know) zeta(i,Jstr-1,kout)=zeta(i,Jstr-1,kout)* & & GRID(ng)%rmask(i,Jstr-1) END IF END DO ! ! Southern edge, implicit Chapman boundary condition. ! ELSE IF (LBC(isouth,isFsur,ng)%Chapman_implicit) THEN DO i=Istr,Iend IF (LBC_apply(ng)%south(i)) THEN cff=dt2d*GRID(ng)%pn(i,Jstr) cff1=SQRT(g*(GRID(ng)%h(i,Jstr)+ & & zeta(i,Jstr,know))) Ce=cff*cff1 cff2=1.0_r8/(1.0_r8+Ce) zeta(i,Jstr-1,kout)=cff2*(zeta(i,Jstr-1,know)+ & & Ce*zeta(i,Jstr,kout)) zeta(i,Jstr-1,kout)=zeta(i,Jstr-1,kout)* & & GRID(ng)%rmask(i,Jstr-1) END IF END DO ! ! Southern edge, clamped boundary condition. ! ELSE IF (LBC(isouth,isFsur,ng)%clamped) THEN DO i=Istr,Iend IF (LBC_apply(ng)%south(i)) THEN zeta(i,Jstr-1,kout)=BOUNDARY(ng)%zeta_south(i) zeta(i,Jstr-1,kout)=zeta(i,Jstr-1,kout)* & & GRID(ng)%rmask(i,Jstr-1) END IF END DO ! ! Southern edge, gradient boundary condition. ! ELSE IF (LBC(isouth,isFsur,ng)%gradient) THEN DO i=Istr,Iend IF (LBC_apply(ng)%south(i)) THEN zeta(i,Jstr-1,kout)=zeta(i,Jstr,kout) zeta(i,Jstr-1,kout)=zeta(i,Jstr-1,kout)* & & GRID(ng)%rmask(i,Jstr-1) END IF END DO ! ! Southern edge, closed boundary condition. ! ELSE IF (LBC(isouth,isFsur,ng)%closed) THEN DO i=Istr,Iend IF (LBC_apply(ng)%south(i)) THEN zeta(i,Jstr-1,kout)=zeta(i,Jstr,kout) zeta(i,Jstr-1,kout)=zeta(i,Jstr-1,kout)* & & GRID(ng)%rmask(i,Jstr-1) END IF END DO END IF END IF ! !----------------------------------------------------------------------- ! Lateral boundary conditions at the northern edge. !----------------------------------------------------------------------- ! IF (DOMAIN(ng)%Northern_Edge(tile)) THEN ! ! Northern edge, implicit upstream radiation condition. ! IF (LBC(inorth,isFsur,ng)%radiation) THEN DO i=Istr,Iend+1 grad(i,Jend )=zeta(i ,Jend ,know)- & & zeta(i-1,Jend ,know) grad(i,Jend )=grad(i,Jend )*GRID(ng)%umask(i,Jend ) grad(i,Jend+1)=zeta(i ,Jend+1,know)- & & zeta(i-1,Jend+1,know) grad(i,Jend+1)=grad(i,Jend+1)*GRID(ng)%umask(i,Jend+1) END DO DO i=Istr,Iend IF (LBC_apply(ng)%north(i)) THEN dZdt=zeta(i,Jend,know)-zeta(i,Jend ,kout) dZde=zeta(i,Jend,kout)-zeta(i,Jend-1,kout) IF (LBC(inorth,isFsur,ng)%nudging) THEN IF ((dZdt*dZde).lt.0.0_r8) THEN tau=FSobc_in(ng,inorth) ELSE tau=FSobc_out(ng,inorth) END IF tau=tau*dt2d END IF IF ((dZdt*dZde).lt.0.0_r8) dZdt=0.0_r8 IF ((dZdt*(grad(i,Jend)+grad(i+1,Jend))).gt.0.0_r8) THEN dZdx=grad(i ,Jend) ELSE dZdx=grad(i+1,Jend) END IF cff=MAX(dZdx*dZdx+dZde*dZde,eps) Cx=MIN(cff,MAX(dZdt*dZdx,-cff)) Ce=dZdt*dZde zeta(i,Jend+1,kout)=(cff*zeta(i,Jend+1,know)+ & & Ce *zeta(i,Jend ,kout)- & & MAX(Cx,0.0_r8)*grad(i ,Jend+1)- & & MIN(Cx,0.0_r8)*grad(i+1,Jend+1))/ & & (cff+Ce) IF (LBC(inorth,isFsur,ng)%nudging) THEN zeta(i,Jend+1,kout)=zeta(i,Jend+1,kout)+ & & tau*(BOUNDARY(ng)%zeta_north(i)- & & zeta(i,Jend+1,know)) END IF zeta(i,Jend+1,kout)=zeta(i,Jend+1,kout)* & & GRID(ng)%rmask(i,Jend+1) END IF END DO ! ! Northern edge, explicit Chapman boundary condition. ! ELSE IF (LBC(inorth,isFsur,ng)%Chapman_explicit) THEN DO i=Istr,Iend IF (LBC_apply(ng)%north(i)) THEN cff=dt2d*GRID(ng)%pn(i,Jend) cff1=SQRT(g*(GRID(ng)%h(i,Jend)+ & & zeta(i,Jend,know))) Ce=cff*cff1 zeta(i,Jend+1,kout)=(1.0_r8-Ce)*zeta(i,Jend+1,know)+ & & Ce*zeta(i,Jend,know) zeta(i,Jend+1,kout)=zeta(i,Jend+1,kout)* & & GRID(ng)%rmask(i,Jend+1) END IF END DO ! ! Northern edge, implicit Chapman boundary condition. ! ELSE IF (LBC(inorth,isFsur,ng)%Chapman_implicit) THEN DO i=Istr,Iend IF (LBC_apply(ng)%north(i)) THEN cff=dt2d*GRID(ng)%pn(i,Jend) cff1=SQRT(g*(GRID(ng)%h(i,Jend)+ & & zeta(i,Jend,know))) Ce=cff*cff1 cff2=1.0_r8/(1.0_r8+Ce) zeta(i,Jend+1,kout)=cff2*(zeta(i,Jend+1,know)+ & & Ce*zeta(i,Jend,kout)) zeta(i,Jend+1,kout)=zeta(i,Jend+1,kout)* & & GRID(ng)%rmask(i,Jend+1) END IF END DO ! ! Northern edge, clamped boundary condition. ! ELSE IF (LBC(inorth,isFsur,ng)%clamped) THEN DO i=Istr,Iend IF (LBC_apply(ng)%north(i)) THEN zeta(i,Jend+1,kout)=BOUNDARY(ng)%zeta_north(i) zeta(i,Jend+1,kout)=zeta(i,Jend+1,kout)* & & GRID(ng)%rmask(i,Jend+1) END IF END DO ! ! Northern edge, gradient boundary condition. ! ELSE IF (LBC(inorth,isFsur,ng)%gradient) THEN DO i=Istr,Iend IF (LBC_apply(ng)%north(i)) THEN zeta(i,Jend+1,kout)=zeta(i,Jend,kout) zeta(i,Jend+1,kout)=zeta(i,Jend+1,kout)* & & GRID(ng)%rmask(i,Jend+1) END IF END DO ! ! Northern edge, closed boundary condition. ! ELSE IF (LBC(inorth,isFsur,ng)%closed) THEN DO i=Istr,Iend IF (LBC_apply(ng)%north(i)) THEN zeta(i,Jend+1,kout)=zeta(i,Jend,kout) zeta(i,Jend+1,kout)=zeta(i,Jend+1,kout)* & & GRID(ng)%rmask(i,Jend+1) END IF END DO END IF END IF ! !----------------------------------------------------------------------- ! Boundary corners. !----------------------------------------------------------------------- ! IF (.not.(EWperiodic(ng).or.NSperiodic(ng))) THEN IF (DOMAIN(ng)%SouthWest_Corner(tile)) THEN IF (LBC_apply(ng)%south(Istr-1).and. & & LBC_apply(ng)%west (Jstr-1)) THEN zeta(Istr-1,Jstr-1,kout)=0.5_r8*(zeta(Istr ,Jstr-1,kout)+ & & zeta(Istr-1,Jstr ,kout)) END IF END IF IF (DOMAIN(ng)%SouthEast_Corner(tile)) THEN IF (LBC_apply(ng)%south(Iend+1).and. & & LBC_apply(ng)%east (Jstr-1)) THEN zeta(Iend+1,Jstr-1,kout)=0.5_r8*(zeta(Iend ,Jstr-1,kout)+ & & zeta(Iend+1,Jstr ,kout)) END IF END IF IF (DOMAIN(ng)%NorthWest_Corner(tile)) THEN IF (LBC_apply(ng)%north(Istr-1).and. & & LBC_apply(ng)%west (Jend+1)) THEN zeta(Istr-1,Jend+1,kout)=0.5_r8*(zeta(Istr-1,Jend ,kout)+ & & zeta(Istr ,Jend+1,kout)) END IF END IF IF (DOMAIN(ng)%NorthEast_Corner(tile)) THEN IF (LBC_apply(ng)%north(Iend+1).and. & & LBC_apply(ng)%east (Jend+1)) THEN zeta(Iend+1,Jend+1,kout)=0.5_r8*(zeta(Iend+1,Jend ,kout)+ & & zeta(Iend ,Jend+1,kout)) END IF END IF END IF ! RETURN END SUBROUTINE zetabc_tile ! END MODULE zetabc_mod