MODULE calc_precipitation_mod

!------------------------------------------------------------------------------!
! Actual revisions:
! -----------------
! 
!
! Former revisions:
! -----------------
! $Log: calc_precipitation.f90,v $
! Revision 1.5  2004/01/30 10:15:57  raasch
! Scalar lower k index nzb replaced by 2d-array nzb_2d
!
! Revision 1.4  2003/03/12 16:21:23  raasch
! Full code replaced in the call for all gridpoints instead of calling the
! _ij version (required by NEC, because otherwise no vectorization)
!
! Revision 1.3  2002/06/11 12:38:58  raasch
! Former subroutine changed to a module which allows to be called for all grid
! points of a single vertical column with index i,j or for all grid points by
! using function overloading.
!
! Revision 1.2  2001/01/22 05:32:25  raasch
! Module test_variables removed
!
! Revision 1.1  2000/04/13 14:45:22  schroeter
! Initial revision
!
!
!
! Description:
! ------------
! Calculate the change of total water content due to precipitation
! (simplified Kessler scheme)
!------------------------------------------------------------------------------!

    PRIVATE
    PUBLIC calc_precipitation

    INTERFACE calc_precipitation
       MODULE PROCEDURE calc_precipitation
       MODULE PROCEDURE calc_precipitation_ij
    END INTERFACE calc_precipitation
 
 CONTAINS


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

       USE arrays_3d
       USE cloud_parameters
       USE constants
       USE indices

       IMPLICIT NONE

       INTEGER ::  i, j, k
       REAL    :: precipitation_rate

 
       DO  i = nxl, nxr
          DO  j = nys, nyn
             DO  k = nzb_2d(j,i)+1, nzt-1    

                IF ( ql(k,j,i) > ql_crit )  THEN
                   precipitation_rate = prec_time_const * &
                                        ( ql(k,j,i) - ql_crit )
                ELSE
                   precipitation_rate = 0.0
                ENDIF
                tend(k,j,i) = tend(k,j,i) - precipitation_rate

             ENDDO
          ENDDO
       ENDDO

    END SUBROUTINE calc_precipitation


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

       USE arrays_3d
       USE cloud_parameters
       USE constants
       USE indices
   
       IMPLICIT NONE

       INTEGER :: i, j, k
       REAL    :: precipitation_rate


       DO  k = nzb_2d(j,i)+1, nzt-1    

          IF ( ql(k,j,i) > ql_crit )  THEN
             precipitation_rate = prec_time_const * ( ql(k,j,i) - ql_crit )
          ELSE
             precipitation_rate = 0.0
          ENDIF
          tend(k,j,i) = tend(k,j,i) - precipitation_rate

       ENDDO

    END SUBROUTINE calc_precipitation_ij

 END MODULE calc_precipitation_mod