SUBROUTINE gastoparticle(pdtphys,zdz,zrho,xlat,pplay,t_seri, &
        id_prec,id_fine, &
        tr_seri,his_g2pgas ,his_g2paer )
  !nhl     .                         fluxso4chem, flux_sparam_sulf,

USE chem_spla_mod_h
  USE chem_mod_h
  USE yoecumf_mod_h
    USE dimphy
  USE infotrac_phy, ONLY: nbtr
   ! USE indice_sol_mod

USE yomcst_mod_h
IMPLICIT NONE
  !


  !
  REAL :: pdtphys
  REAL :: zrho(klon,klev)
  REAL :: zdz(klon,klev)
  REAL :: tr_seri(klon,klev,nbtr)   ! traceurs
  REAL :: tend                 ! tendance par espece
  REAL :: xlat(klon)       ! latitudes pour chaque point
  REAL :: pi
  !   JE: 20140120
  REAL :: his_g2pgas(klon)
  REAL :: his_g2paer(klon)
  REAL :: tendincm3(klon,klev)
  REAL :: tempvar(klon,klev)
  REAL :: pplay(klon,klev)
  REAL :: t_seri(klon,klev)
  REAL :: tend2d(klon,klev)
  INTEGER :: id_prec,id_fine
  !
  !------------------------- Scaling Parameter --------------------------
  !
  !  REAL scale_param_so4(klon)  !Scaling parameter for sulfate

  INTEGER :: i, k
  REAL :: tau_chem     !---chemical lifetime in s
  !
  !------------------------- Variables to save --------------------------
  !
  !nhl      REAL fluxso4chem(klon,klev)
  !nhl      REAL flux_sparam_sulf(klon,klev)

  !======================================================================
  pi=atan(1.)*4.
  !
  IF (id_prec>0 .AND. id_fine>0) THEN
  DO k = 1, klev
  DO i = 1, klon
  !
  !    tau_chem=scale_param_so4(i)*86400.*(8.-5.*cos(xlat(i)*pi/180.))    !tchemfctn2
  !nhl        tau_chem=86400.*(8.-5.*cos(xlat(i)*pi/180.))    !tchemfctn2
    tau_chem=86400.*(5.-4.*cos(xlat(i)*pi/180.))    !
    tend=tr_seri(i,k,id_prec)*(1.-exp(-pdtphys/tau_chem)) ! Sulfate production
  !nhl        tend=(1.-exp(-pdtphys/tau_chem))
  !nhl        tend=scale_param_so4(i) !as this it works
  !
    tr_seri(i,k,id_prec) =tr_seri(i,k,id_prec) - tend
    tr_seri(i,k,id_fine) =tr_seri(i,k,id_fine) + &
          tend/RNAVO*masse_ammsulfate  !--gAER/KgAir
    tend2d(i,k)=tend
  !
  !nhl        fluxso4chem(i,k) = tend/RNAVO*masse_ammsulfate
  !nhl        flux_sparam_sulf(i,k) = tend/RNAVO*masse_ammsulfate
  ENDDO
  ENDDO



    tempvar=tend2d
     CALL kg_to_cm3(pplay,t_seri,tempvar)
    tendincm3=tempvar

  DO k = 1, klev
  DO i = 1, klon

     ! his_g2pgas(i) = his_g2pgas(i) + tendincm3(i,k)*1e6*zdz(i,k)/pdtphys
    his_g2paer(i) = his_g2paer(i) + &
          tendincm3(i,k)/RNAVO*masse_ammsulfate*1.e3* &
          1.e6*zdz(i,k)/pdtphys    ! mg/m2/s
    his_g2pgas(i) = his_g2paer(i)*masse_s/masse_ammsulfate ! mg-S/m2/s

  ENDDO
  ENDDO
  ENDIF

  !
  RETURN
END SUBROUTINE gastoparticle