MODULE trc
   !!======================================================================
   !!                      ***  MODULE  trc  ***
   !! Passive tracers   :  module for tracers defined
   !!======================================================================
   !! History :    -   !  1996-01  (M. Levy)  Original code
   !!              -   !  1999-07  (M. Levy)  for LOBSTER1 or NPZD model
   !!              -   !  2000-04  (O. Aumont, M.A. Foujols)  HAMOCC3 and P3ZD
   !!             1.0  !  2004-03  (C. Ethe)  Free form and module
   !!----------------------------------------------------------------------
   !! NEMO/TOP 1.0 , LOCEAN-IPSL (2005) 
   !! $Id$ 
   !! Software governed by the CeCILL licence (modipsl/doc/NEMO_CeCILL.txt)
   !!----------------------------------------------------------------------
#if defined key_top
   !!----------------------------------------------------------------------
   !!   'key_top'                                                TOP models
   !!----------------------------------------------------------------------
   USE par_oce
   USE par_trc
   
   IMPLICIT NONE
   PUBLIC

   !! passive tracers names and units (read in namelist)
   !! --------------------------------------------------
   CHARACTER(len=12), PUBLIC, DIMENSION(jptra) ::   ctrcnm     !: tracer name 
   CHARACTER(len=12), PUBLIC, DIMENSION(jptra) ::   ctrcun     !: tracer unit
   CHARACTER(len=80), PUBLIC, DIMENSION(jptra) ::   ctrcnl     !: tracer long name 
   
   
   !! parameters for the control of passive tracers
   !! --------------------------------------------------
   INTEGER, PUBLIC                   ::   numnat   !: the number of the passive tracer NAMELIST
   LOGICAL, PUBLIC, DIMENSION(jptra) ::   lutini   !:  initialisation from FILE or not (NAMELIST)
   LOGICAL, PUBLIC, DIMENSION(jptra) ::   lutsav   !:  logical for saving tracer or not
   INTEGER, PUBLIC, DIMENSION(jptra) ::   nutini   !: FORTRAN LOGICAL UNIT for initialisation file

   !! passive tracers fields (before,now,after)
   !! --------------------------------------------------
   REAL(wp), PUBLIC ::   trai       !: initial total tracer
   REAL(wp), PUBLIC ::   areatot    !: total volume 

   REAL(wp), PUBLIC, DIMENSION (jpi,jpj,jpk,jptra) ::   trn   !: traceur concentration for actual time step
   REAL(wp), PUBLIC, DIMENSION (jpi,jpj,jpk,jptra) ::   tra   !: traceur concentration for next time step
   REAL(wp), PUBLIC, DIMENSION (jpi,jpj,jpk,jptra) ::   trb   !: traceur concentration for before time step


   !! numerical parameter (NAMELIST)
   !! --------------------------------------------------
   REAL(wp), PUBLIC ::   rsc    !: tuning coefficient for anti-diffusion
   REAL(wp), PUBLIC ::   rtrn   !: value for truncation

   !! namelist parameters
   !! --------------------------------------------------
   INTEGER , PUBLIC ::   ncortrc     !: number of corrective phases
   INTEGER , PUBLIC ::   ndttrc      !: frequency of step on passive tracers
   INTEGER , PUBLIC ::   nittrc000   !: first time step of passive tracers model  
   LOGICAL , PUBLIC ::   crosster    !: logical if true computes crossterms


   !! isopycnal scheme for passive tracers
   !! ------------------------------------  
   REAL(wp), PUBLIC ::   ahtrb0     !: background diffusivity coefficient for passive tracer (m2/s)
   REAL(wp), PUBLIC ::   trcrat     !: ratio between passive and active tracer coeff for diffusion
   REAL(wp), PUBLIC ::   ahtrc0     !: horizontal eddy diffusivity for passive tracers (m2/s)
   REAL(wp), PUBLIC ::   aeivtr0    !: eddy induced velocity coefficient (m2/s)
   
   
   !! passive tracers restart (input and output)
   !! ------------------------------------------  
   LOGICAL , PUBLIC ::   lrsttr     !: boolean term for restart i/o for passive tracers (namelist)
   INTEGER , PUBLIC ::   nutwrs     !: output FILE for passive tracers restart
   INTEGER , PUBLIC ::   nutrst     !: logical unit for restart FILE for passive tracers
   INTEGER , PUBLIC ::   nrsttr     !: control of the time step ( 0 or 1 ) for pass. tr.
   
   
   !! interpolated gradient
   !!--------------------------------------------------  
   REAL(wp), PUBLIC, DIMENSION (jpi,jpj,jptra) ::   gtru   !: horizontal gradient at u-points at bottom ocean level
   REAL(wp), PUBLIC, DIMENSION (jpi,jpj,jptra) ::   gtrv   !: horizontal gradient at v-points at bottom ocean level

   
# if defined key_trcldf_eiv && defined key_diaeiv
   !! The three component of the eddy induced velocity
   !! --------------------------------------------------
   REAL(wp), PUBLIC, DIMENSION (jpi,jpj,jpk) ::   u_trc_eiv   !: u-eiv (m/s)
   REAL(wp), PUBLIC, DIMENSION (jpi,jpj,jpk) ::   v_trc_eiv   !: v-eiv (m/s)
   REAL(wp), PUBLIC, DIMENSION (jpi,jpj,jpk) ::   w_trc_eiv   !: w-eiv (m/s)
# endif
   
   
   !! information for outputs
   !! --------------------------------------------------
   INTEGER , PUBLIC ::   nwritetrc   !: time step frequency for concentration outputs (namelist)
   
# if defined key_trc_diaadd
   !! additional 2D/3D outputs namelist
   !! --------------------------------------------------
   CHARACTER(len= 8), PUBLIC, DIMENSION (jpdia2d) ::   ctrc2d   !: 2d output field name
   CHARACTER(len= 8), PUBLIC, DIMENSION (jpdia2d) ::   ctrc2u   !: 2d output field unit   
   CHARACTER(len= 8), PUBLIC, DIMENSION (jpdia3d) ::   ctrc3d   !: 3d output field name
   CHARACTER(len= 8), PUBLIC, DIMENSION (jpdia3d) ::   ctrc3u   !: 3d output field unit
   CHARACTER(len=80), PUBLIC, DIMENSION (jpdia2d) ::   ctrc2l   !: 2d output field long name
   CHARACTER(len=80), PUBLIC, DIMENSION (jpdia3d) ::   ctrc3l   !: 3d output field long name

   
   REAL(wp), PUBLIC, DIMENSION (jpi,jpj,    jpdia2d) ::   trc2d   !:  additional 2d outputs  
   REAL(wp), PUBLIC, DIMENSION (jpi,jpj,jpk,jpdia3d) ::   trc3d   !:  additional 3d outputs  
   
   
   !! netcdf files and index common
   !! --------------------------------------------------
   INTEGER , PUBLIC ::   nwritedia     !: frequency of additional arrays outputs(namelist)
# endif
   
# if defined key_trc_diatrd
   
   !!  non conservative trends (biological, ...)
   !! --------------------------------------------------
   LOGICAL, PUBLIC, DIMENSION (jptra) ::   luttrd   !: large trends diagnostic to write or not (namelist)
   
   !!  Advection-diffusion trends
   !! --------------------------------------------------
   REAL(wp), PUBLIC, DIMENSION(:,:,:,:,:), ALLOCATABLE ::   trtrd   !: trends of the tracer equations
   
   INTEGER, PUBLIC, DIMENSION(jptra) :: ikeep ! indice of tracer for which dyn trends are stored
   INTEGER, PUBLIC                   :: nkeep ! number of tracers for which dyn trends are stored 
   !                                          ! (used to allocate trtrd buffer)

   !! netcdf files and index common
   !! --------------------------------------------------
   INTEGER , PUBLIC ::   nwritetrd   !: frequency of additional arrays outputs(namelist)
   
# endif 
   
   !! passive tracers data read and at given time_step
   !! --------------------------------------------------
# if defined key_dtatrc
   INTEGER , PUBLIC, DIMENSION(jptra) ::   numtr   !: logical unit for passive tracers data
# endif

#else
   !!----------------------------------------------------------------------
   !!  Empty module :                                     No passive tracer
   !!----------------------------------------------------------------------
#endif

   !!======================================================================
END MODULE trc