MODULE advec_v_up_mod

!------------------------------------------------------------------------------!
! Current revisions:
! -----------------
! 
!
! Former revisions:
! -----------------
! $Id: advec_v_up.f90 484 2010-02-05 07:36:54Z fricke $
!
! 106 2007-08-16 14:30:26Z raasch
! j loop is starting from nysv (needed for non-cyclic boundary conditions)
!
! 75 2007-03-22 09:54:05Z raasch
! vynp eliminated
!
! RCS Log replace by Id keyword, revision history cleaned up
!
! Revision 1.12  2006/02/23 09:46:37  raasch
! nzb_2d replaced by nzb_v_inner
!
! Revision 1.1  1997/08/29 08:56:05  raasch
! Initial revision
!
!
! Description:
! ------------
! Advection term for the v velocity-component using upstream scheme.
! NOTE: vertical advection at k=1 still has wrong grid spacing for w>0!
!       The same problem occurs for all topography boundaries!
!------------------------------------------------------------------------------!

    PRIVATE
    PUBLIC advec_v_up

    INTERFACE advec_v_up
       MODULE PROCEDURE advec_v_up
       MODULE PROCEDURE advec_v_up_ij
    END INTERFACE advec_v_up

 CONTAINS


!------------------------------------------------------------------------------!
! Call for all grid points
!------------------------------------------------------------------------------!
    SUBROUTINE advec_v_up

       USE arrays_3d
       USE control_parameters
       USE grid_variables
       USE indices

       IMPLICIT NONE

       INTEGER ::  i, j, k
       REAL    ::  ukomp, vkomp, wkomp


       DO  i = nxl, nxr
          DO  j = nysv, nyn
             DO  k = nzb_v_inner(j,i)+1, nzt
!
!--             x-direction
                ukomp = 0.25 * ( u(k,j,i)   + u(k,j-1,i) + &
                                 u(k,j,i+1) + u(k,j-1,i+1) ) - u_gtrans
                IF ( ukomp > 0.0 )  THEN
                   tend(k,j,i) = tend(k,j,i) - ukomp * &
                                         ( v(k,j,i) - v(k,j,i-1) ) * ddx
                ELSE
                   tend(k,j,i) = tend(k,j,i) - ukomp * &
                                         ( v(k,j,i+1) - v(k,j,i) ) * ddx
                ENDIF
!
!--             y-direction
                vkomp = v(k,j,i) - v_gtrans
                IF ( vkomp > 0.0 )  THEN
                   tend(k,j,i) = tend(k,j,i) - vkomp * &
                                         ( v(k,j,i) - v(k,j-1,i) ) * ddy
                ELSE
                   tend(k,j,i) = tend(k,j,i) - vkomp * &
                                         ( v(k,j+1,i) - v(k,j,i) ) * ddy
                ENDIF
!
!--             z-direction
                wkomp = 0.25 * ( w(k,j,i)  + w(k-1,j,i) + &
                                 w(k,j-1,i) + w(k-1,j-1,i) )
                IF ( wkomp > 0.0 )  THEN
                   tend(k,j,i) = tend(k,j,i) - wkomp * &
                                         ( v(k,j,i) - v(k-1,j,i) ) * ddzu(k)
                ELSE
                   tend(k,j,i) = tend(k,j,i) - wkomp * &
                                         ( v(k+1,j,i) - v(k,j,i) ) * ddzu(k+1)
                ENDIF

             ENDDO
          ENDDO
       ENDDO

    END SUBROUTINE advec_v_up


!------------------------------------------------------------------------------!
! Call for grid point i,j
!------------------------------------------------------------------------------!
    SUBROUTINE advec_v_up_ij( i, j )

       USE arrays_3d
       USE control_parameters
       USE grid_variables
       USE indices

       IMPLICIT NONE

       INTEGER ::  i, j, k

       REAL ::  ukomp, vkomp, wkomp


       DO  k = nzb_v_inner(j,i)+1, nzt
!
!--       x-direction
          ukomp = 0.25 * ( u(k,j,i) + u(k,j-1,i) + u(k,j,i+1) + u(k,j-1,i+1) &
                         ) - u_gtrans
          IF ( ukomp > 0.0 )  THEN
             tend(k,j,i) = tend(k,j,i) - ukomp * &
                                         ( v(k,j,i) - v(k,j,i-1) ) * ddx
          ELSE
             tend(k,j,i) = tend(k,j,i) - ukomp * &
                                         ( v(k,j,i+1) - v(k,j,i) ) * ddx
          ENDIF
!
!--       y-direction
          vkomp = v(k,j,i) - v_gtrans
          IF ( vkomp > 0.0 )  THEN
             tend(k,j,i) = tend(k,j,i) - vkomp * &
                                         ( v(k,j,i) - v(k,j-1,i) ) * ddy
          ELSE
             tend(k,j,i) = tend(k,j,i) - vkomp * &
                                         ( v(k,j+1,i) - v(k,j,i) ) * ddy
          ENDIF
!
!--       z-direction
          wkomp = 0.25 * ( w(k,j,i) + w(k-1,j,i) + w(k,j-1,i) + w(k-1,j-1,i) )
          IF ( wkomp > 0.0 )  THEN
             tend(k,j,i) = tend(k,j,i) - wkomp * &
                                         ( v(k,j,i) - v(k-1,j,i) ) * ddzu(k)
          ELSE
             tend(k,j,i) = tend(k,j,i) - wkomp * &
                                         ( v(k+1,j,i) - v(k,j,i) ) * ddzu(k+1)
          ENDIF

       ENDDO

    END SUBROUTINE advec_v_up_ij

 END MODULE advec_v_up_mod