SUBROUTINE lpm_calc_liquid_water_content

!------------------------------------------------------------------------------!
! Current revisions:
! ------------------
! 
!
! Former revisions:
! -----------------
! $Id: lpm_calc_liquid_water_content.f90 850 2012-03-15 12:09:25Z gryschka $
!
! 849 2012-03-15 10:35:09Z raasch
! initial revision (former part of advec_particles)
!
!
! Description:
! ------------
! Calculate the liquid water content for each grid box.
!------------------------------------------------------------------------------!

    USE arrays_3d
    USE cloud_parameters
    USE constants
    USE control_parameters
    USE cpulog
    USE grid_variables
    USE indices
    USE interfaces
    USE particle_attributes

    IMPLICIT NONE

    INTEGER ::  i, j, k, n, psi


    CALL cpu_log( log_point_s(45), 'lpm_calc_ql', 'start' )

!
!-- Set water content initially to zero
    ql = 0.0;  ql_v = 0.0;  ql_vp = 0.0

!
!-- Calculate for each grid box
    DO  i = nxl, nxr
       DO  j = nys, nyn
          DO  k = nzb, nzt+1

!
!--          Calculate the total volume in the boxes (ql_v, weighting factor
!--          has to beincluded)
             psi = prt_start_index(k,j,i)
             DO  n = psi, psi+prt_count(k,j,i)-1
                ql_v(k,j,i)  = ql_v(k,j,i)  + particles(n)%weight_factor *  &
                                              particles(n)%radius**3
             ENDDO

!
!--          Calculate the liquid water content
             IF ( ql_v(k,j,i) /= 0.0 )  THEN
                ql(k,j,i) = ql(k,j,i) + rho_l * 1.33333333 * pi *           &
                                        ql_v(k,j,i) /                       &
                                        ( rho_surface * dx * dy * dz )

                IF ( ql(k,j,i) < 0.0 ) THEN
                   WRITE( message_string, * )  'LWC out of range: ' , &
                                               ql(k,j,i)
                   CALL message( 'lpm_calc_liquid_water_content', '', 2, 2, &
                                 -1, 6, 1 )
                ENDIF

             ELSE

                ql(k,j,i) = 0.0

             ENDIF

          ENDDO
       ENDDO
    ENDDO

    CALL cpu_log( log_point_s(45), 'lpm_calc_ql', 'stop' )


 END SUBROUTINE lpm_calc_liquid_water_content