module tracer_h

       implicit none

       integer, save :: nqtot ! total number of tracers
       integer, save :: nesp  ! number of species in the chemistry
       integer, save :: ngt   ! number of generic tracers
       integer, save :: n_rgcs ! number of Radiative Generic Condensable Species
!$OMP THREADPRIVATE(nqtot,nesp,ngt,n_rgcs)

       logical :: moderntracdef=.false. ! Standard or modern traceur.def
!$OMP THREADPRIVATE(moderntracdef)

       character*30, save, allocatable :: noms(:)   ! name of the tracer
       real, save, allocatable :: mmol(:)     ! mole mass of tracer (g/mol) 
       real, save, allocatable :: aki(:)      ! to compute coefficient of thermal concduction if photochem
       real, save, allocatable :: cpi(:)      ! to compute cpnew in concentration.F if photochem
       real, save, allocatable :: radius(:)   ! dust and ice particle radius (m)
       real, save, allocatable :: rho_q(:)    ! tracer densities (kg.m-3)
       real, save, allocatable :: qext(:)     ! Single Scat. Extinction coeff at 0.67 um
       real, save, allocatable :: alpha_lift(:)  ! saltation vertical flux/horiz flux ratio (m-1)
       real, save, allocatable :: alpha_devil(:) ! lifting coeeficient by dust devil
       real, save, allocatable :: qextrhor(:) ! Intermediate for computing opt. depth from q

       real,save :: varian      ! Characteristic variance of log-normal distribution
       real,save :: r3n_q     ! used to compute r0 from number and mass mixing ratio
       real,save :: rho_dust     ! Mars dust density (kg.m-3)
       real,save :: rho_ice     ! Water ice density (kg.m-3)
       real,save :: rho_co2     ! CO2 ice density (kg.m-3)
       real,save :: ref_r0        ! for computing reff=ref_r0*r0 (in log.n. distribution)
!$OMP THREADPRIVATE(noms,mmol,aki,cpi,radius,rho_q,qext,alpha_lift,alpha_devil,qextrhor, &
	!$OMP varian,r3n_q,rho_dust,rho_ice,rho_co2,ref_r0)

       integer, save, allocatable :: is_chim(:) ! 1 if tracer used in chemistry, else 0
       integer, save, allocatable :: is_rad(:)  ! 1 if   ""    ""  in radiative transfer, else 0
!$OMP THREADPRIVATE(is_chim,is_rad)

       integer, save, allocatable :: is_recomb(:)      ! 1 if tracer used in recombining scheme, else 0 (if 1, must have is_rad=1)
       integer, save, allocatable :: is_recomb_qset(:) ! 1 if tracer k-corr assume predefined vmr, else 0 (if 1, must have is_recomb=1)
       integer, save, allocatable :: is_recomb_qotf(:) ! 1 if tracer recombination is done on-the-fly, else 0 (if 1, must have is_recomb_qset=0)
!$OMP THREADPRIVATE(is_recomb,is_recomb_qset,is_recomb_qotf)
       integer, save, allocatable :: is_condensable(:)      ! 1 if tracer is generic, else 0 (added LT)
       integer,save,allocatable :: is_rgcs(:)               ! 1 if tracer is a radiative generic condensable specie, else 0 (added LT 2022)
       ! Lists of constants for condensable tracers
       real, save, allocatable :: constants_mass(:)                    ! molecular mass of the specie (g/mol)
       real, save, allocatable :: constants_delta_vapH(:)           ! Enthalpy of vaporization (J/mol)
       real, save, allocatable :: constants_Tref(:)                 ! Ref temperature for Clausis-Clapeyron (K)
       real, save, allocatable :: constants_Pref(:)                 ! Reference pressure for Clausius Clapeyron (Pa)
       real, save, allocatable :: constants_epsi_generic(:)                 ! fractionnal molecular mass (m/mugaz)
       real, save, allocatable :: constants_RLVTT_generic(:)                ! Latent heat of vaporization (J/kg)
       real, save, allocatable :: constants_metallicity_coeff(:)    ! Coefficient to take into account the metallicity
       real, save, allocatable :: constants_RCPV_generic(:)                   ! specific heat capacity of the tracer vapor at Tref
!$OMP THREADPRIVATE(constants_mass,constants_delta_vapH,constants_Tref)
!$OMP THREADPRIVATE(constants_Pref,constants_epsi_generic)
!$OMP THREADPRIVATE(constants_RLVTT_generic,constants_metallicity_coeff,constants_RCPV_generic)

!$OMP THREADPRIVATE(is_condensable,is_rgcs)   !also added by LT
! tracer indexes: these are initialized in initracer and should be 0 if the
!                 corresponding tracer does not exist
       ! dust
       integer,save,allocatable :: igcm_dustbin(:) ! for dustbin 'dust' tracers
       ! dust, special doubleq case
       integer,save :: igcm_dust_mass   ! dust mass mixing ratio (for transported dust)
       integer,save :: igcm_dust_number ! dust number mixing ratio (transported dust)
       ! water
       integer,save :: igcm_h2o_vap ! water vapour
       integer,save :: igcm_h2o_ice ! water ice
       ! chemistry:
       integer,save :: igcm_co2
       integer,save :: igcm_co
       integer,save :: igcm_o
       integer,save :: igcm_o1d
       integer,save :: igcm_o2
       integer,save :: igcm_o3
       integer,save :: igcm_h
       integer,save :: igcm_h2
       integer,save :: igcm_oh
       integer,save :: igcm_ho2
       integer,save :: igcm_h2o2
       integer,save :: igcm_n2
       integer,save :: igcm_ar
       integer,save :: igcm_n
       integer,save :: igcm_no
       integer,save :: igcm_no2
       integer,save :: igcm_n2d
       integer,save :: igcm_ch4

       integer,save :: igcm_ch3
       integer,save :: igcm_ch
       integer,save :: igcm_3ch2
       integer,save :: igcm_1ch2
       integer,save :: igcm_cho
       integer,save :: igcm_ch2o
       integer,save :: igcm_ch3o
       integer,save :: igcm_c
       integer,save :: igcm_c2
       integer,save :: igcm_c2h
       integer,save :: igcm_c2h2
       integer,save :: igcm_c2h3
       integer,save :: igcm_c2h4
       integer,save :: igcm_c2h6
       integer,save :: igcm_ch2co
       integer,save :: igcm_ch3co
       integer,save :: igcm_hcaer

       ! other tracers
       integer,save :: igcm_ar_n2 ! for simulations using co2 +neutral gaz
       integer,save :: igcm_co2_ice ! CO2 ice 
!$OMP THREADPRIVATE(igcm_dustbin,igcm_dust_mass,igcm_dust_number,igcm_h2o_vap,igcm_h2o_ice,      &
	!$OMP igcm_co2,igcm_co,igcm_o,igcm_o1d,igcm_o2,igcm_o3,igcm_h,igcm_h2,igcm_oh,	      &
	!$OMP igcm_ho2,igcm_h2o2,igcm_n2,igcm_ar,igcm_ar_n2,igcm_co2_ice,                         &
       !$OMP igcm_n,igcm_no,igcm_no2,igcm_n2d,igcm_ch4,igcm_ch3,igcm_ch,igcm_3ch2,               &
       !$OMP igcm_1ch2,igcm_cho,igcm_ch2o,igcm_ch3o,igcm_c,igcm_c2,igcm_c2h,igcm_c2h2,           &
       !$OMP igcm_c2h3,igcm_c2h4,igcm_c2h6,igcm_ch2co,igcm_ch3co,igcm_hcaer)

       contains
       
       ! some basic auxiliary functions for tracers
       
       logical function is_known_tracer(tracer_name)
         ! checks if tracer_name is a know tracer
         ! returns .true. if yes and .false. otherwise
         implicit none
         character(len=*),intent(in) :: tracer_name
         integer :: iq
         ! initialization
         is_known_tracer=.false.
         do iq=1,nqtot
           if( trim(tracer_name) == trim(noms(iq)) ) then
             is_known_tracer=.true.
             exit
           endif
         enddo
       end function is_known_tracer
       
       integer function tracer_index(tracer_name)
         ! gets the index of the tracer tracer_name
         ! returns index or 0 if unknown tracer
         implicit none
         character(len=*),intent(in) :: tracer_name
         integer :: iq
         ! initialization
         tracer_index=0
         do iq=1,nqtot
           if( trim(tracer_name) == trim(noms(iq)) ) then
             tracer_index=iq
             exit
           endif
         enddo
       end function tracer_index
        
       end module tracer_h