SUBROUTINE callsedim(ngrid,nlay, ptimestep,
     &                pplev,zlev, pt, pdt,
     &                pq, pdqfi, pdqsed,pdqs_sed,nq)

      use radinc_h, only : naerkind
      ! use radii_mod, only: h2o_reffrad
      ! use aerosol_mod, only : iaero_h2o
      USE tracer_h, only : igcm_haze,radius,rho_q
      use comcstfi_mod, only: g

      IMPLICIT NONE

!==================================================================
!
!     Purpose
!     -------
!     Calculates sedimentation of aerosols depending on their
!     density and radius.
!
!     Authors
!     -------
!     F. Forget (1999)
!     Tracer generalisation by E. Millour (2009)
!
!==================================================================

c-----------------------------------------------------------------------
c   declarations:
c   -------------

c   arguments:
c   ----------

      integer,intent(in):: ngrid ! number of horizontal grid points
      integer,intent(in):: nlay  ! number of atmospheric layers
      real,intent(in):: ptimestep  ! physics time step (s)
      real,intent(in):: pplev(ngrid,nlay+1) ! pressure at inter-layers (Pa)
      real,intent(in):: pt(ngrid,nlay)      ! temperature at mid-layer (K)
      real,intent(in):: pdt(ngrid,nlay) ! tendency on temperature
      real,intent(in):: zlev(ngrid,nlay+1)  ! altitude at layer boundaries
      integer,intent(in) :: nq ! number of tracers
      real,intent(in) :: pq(ngrid,nlay,nq)  ! tracers (kg/kg)
      real,intent(in) :: pdqfi(ngrid,nlay,nq)  ! tendency on tracers before
                                               ! sedimentation (kg/kg.s-1)

      real,intent(out) :: pdqsed(ngrid,nlay,nq) ! tendency due to sedimentation (kg/kg.s-1)
      real,intent(out) :: pdqs_sed(ngrid,nq)    ! flux at surface (kg.m-2.s-1)

c   local:
c   ------

      INTEGER l,ig, iq

      ! for particles with varying radii:
      real,allocatable,save :: reffrad(:,:,:) ! particle radius (m)
      real,allocatable,save :: nueffrad(:,:,:) ! aerosol effective radius variance
!$OMP THREADPRIVATE(reffrad,nueffrad)

      real zqi(ngrid,nlay,nq) ! to locally store tracers
      real zt(ngrid,nlay) ! to locally store temperature (K)
      real masse (ngrid,nlay) ! Layer mass (kg.m-2)
      real epaisseur (ngrid,nlay) ! Layer thickness (m)
      real wq(ngrid,nlay+1) ! displaced tracer mass (kg.m-2)
c      real dens(ngrid,nlay) ! Mean density of the ice part. accounting for dust core


      LOGICAL,SAVE :: firstcall=.true.
!$OMP THREADPRIVATE(firstcall)

c    ** un petit test de coherence
c       --------------------------

      IF (firstcall) THEN
        firstcall=.false.
        ! add some tests on presence of required tracers/aerosols:
        ! allocate "naerkind" size local arrays (which are also
        ! "saved" so that this is done only once in for all even if
        ! we don't need to store the value from a time step to the next)
        allocate(reffrad(ngrid,nlay,naerkind))
        allocate(nueffrad(ngrid,nlay,naerkind))
      ENDIF ! of IF (firstcall)

!=======================================================================
!     Preliminary calculation of the layer characteristics
!     (mass (kg.m-2), thickness (m), etc.

      do  l=1,nlay
        do ig=1, ngrid
          masse(ig,l)=(pplev(ig,l) - pplev(ig,l+1)) /g
          epaisseur(ig,l)= zlev(ig,l+1) - zlev(ig,l)
          zt(ig,l)=pt(ig,l)+pdt(ig,l)*ptimestep
        end do
      end do

!======================================================================
! Calculate the transport due to sedimentation for each tracer
! [This has been rearranged by L. Kerber to allow the sedimentation
!  of general tracers.]

      do iq=1,nq
       if((radius(iq).gt.1.e-9)) then ! JVO 08/2017 : be careful radius was tested uninitialized (fixed) ...

!         (no sedim for gases, and n2_ice sedim is done in condense_n2)

! store locally updated tracers

          do l=1,nlay
            do ig=1, ngrid
              zqi(ig,l,iq)=pq(ig,l,iq)+pdqfi(ig,l,iq)*ptimestep
            enddo
          enddo ! of do l=1,nlay

!======================================================================
! Sedimentation
!======================================================================
! Water      !AF24: deleted

! ! General Case
!        else
             call newsedim(ngrid,nlay,1,ptimestep,
     &            pplev,masse,epaisseur,zt,radius(iq),rho_q(iq),
     &            zqi(1,1,iq),wq,iq)
      !  endif

!=======================================================================
!     Calculate the tendencies
!======================================================================

          do ig=1,ngrid
!     Ehouarn: with new way of tracking tracers by name, this is simply
            pdqs_sed(ig,iq) = wq(ig,1)/ptimestep
          end do

          DO l = 1, nlay
            DO ig=1,ngrid
              pdqsed(ig,l,iq)=(zqi(ig,l,iq)-
     &        (pq(ig,l,iq) + pdqfi(ig,l,iq)*ptimestep))/ptimestep
            ENDDO
          ENDDO
       endif ! of no gases no n2_ice
      enddo ! of do iq=1,nq
      return
      end