source: LMDZ4/trunk/libf/dyn3d/limit_netcdf.F90 @ 2690

!
! $Id: limit_netcdf.F90 1425 2010-09-02 13:45:23Z oboucher $
!-------------------------------------------------------------------------------
!
SUBROUTINE limit_netcdf(interbar, extrap, oldice, masque)
!
!-------------------------------------------------------------------------------
! Author : L. Fairhead, 27/01/94
!-------------------------------------------------------------------------------
! Purpose: Boundary conditions files building for new model using climatologies.
!          Both grids have to be regular.
!-------------------------------------------------------------------------------
! Note: This routine is designed to work for Earth
!-------------------------------------------------------------------------------
! Modification history:
!  * 23/03/1994: Z. X. Li
!  *    09/1999: L. Fairhead (netcdf reading in LMDZ.3.3)
!  *    07/2001: P. Le Van
!  *    11/2009: L. Guez     (ozone day & night climatos, see etat0_netcdf.F90)
!  *    12/2009: D. Cugnet   (f77->f90, calendars, files from coupled runs)
!-------------------------------------------------------------------------------
  USE control_mod
#ifdef CPP_EARTH
  USE dimphy
  USE ioipsl,             ONLY : ioget_year_len
  USE phys_state_var_mod, ONLY : pctsrf
  USE netcdf,             ONLY : NF90_OPEN,    NF90_CREATE,  NF90_CLOSE,       &
                   NF90_DEF_DIM, NF90_DEF_VAR, NF90_PUT_VAR, NF90_PUT_ATT,     &
                   NF90_NOERR,   NF90_NOWRITE, NF90_DOUBLE,  NF90_GLOBAL,      &
                   NF90_CLOBBER, NF90_ENDDEF,  NF90_UNLIMITED, NF90_FLOAT
  USE inter_barxy_m, only: inter_barxy
#endif
  IMPLICIT NONE
!-------------------------------------------------------------------------------
! Arguments:
#include "dimensions.h"
#include "paramet.h"
#include "iniprint.h"
  LOGICAL,                    INTENT(IN) :: interbar ! barycentric interpolation
  LOGICAL,                    INTENT(IN) :: extrap   ! SST extrapolation flag
  LOGICAL,                    INTENT(IN) :: oldice   ! old way ice computation
  REAL, DIMENSION(iip1,jjp1), INTENT(IN) :: masque   ! land mask
#ifndef CPP_EARTH
  WRITE(lunout,*)'limit_netcdf: Earth-specific routine, needs Earth physics'
#else
!-------------------------------------------------------------------------------
! Local variables:
#include "logic.h"
#include "comvert.h"
#include "comgeom2.h"
#include "comconst.h"
#include "indicesol.h"

!--- For fractionary sub-cell use (old coding used soil index: 0,1,2,3) --------
  LOGICAL, PARAMETER :: fracterre=.TRUE.

!--- INPUT NETCDF FILES NAMES --------------------------------------------------
  CHARACTER(LEN=25) :: icefile, sstfile, dumstr
  CHARACTER(LEN=25), PARAMETER :: famipsst='amipbc_sst_1x1.nc        ',        &
                                  famipsic='amipbc_sic_1x1.nc        ',        &
                                  fclimsst='amipbc_sst_1x1_clim.nc   ',        &
                                  fclimsic='amipbc_sic_1x1_clim.nc   ',        &
                                  fcpldsst='cpl_atm_sst.nc           ',        &
                                  fcpldsic='cpl_atm_sic.nc           ',        &
                                  frugo   ='Rugos.nc                 ',        &
                                  falbe   ='Albedo.nc                '

!--- OUTPUT VARIABLES FOR NETCDF FILE ------------------------------------------
  REAL,   DIMENSION(klon)                :: fi_ice, verif
  REAL,   DIMENSION(:,:),   POINTER      :: phy_rug=>NULL(), phy_ice=>NULL()
  REAL,   DIMENSION(:,:),   POINTER      :: phy_sst=>NULL(), phy_alb=>NULL()
  REAL,   DIMENSION(:,:),   ALLOCATABLE  :: phy_bil
  REAL,   DIMENSION(:,:,:), ALLOCATABLE  :: pctsrf_t
  INTEGER                                :: nbad

!--- VARIABLES FOR OUTPUT FILE WRITING -----------------------------------------
  INTEGER :: ierr, nid, ndim, ntim, k
  INTEGER, DIMENSION(2) :: dims
  INTEGER :: id_tim,  id_SST,  id_BILS, id_RUG, id_ALB
  INTEGER :: id_FOCE, id_FSIC, id_FTER, id_FLIC
  INTEGER :: NF90_FORMAT
  LOGICAL :: lCPL                    !--- T: IPCC-IPSL cpl model output files
  INTEGER :: ndays                   !--- Depending on the output calendar

!--- INITIALIZATIONS -----------------------------------------------------------
#ifdef NC_DOUBLE
  NF90_FORMAT=NF90_DOUBLE
#else
  NF90_FORMAT=NF90_FLOAT
#endif

  pi    = 4.*ATAN(1.)
  rad   = 6371229.
  daysec= 86400.
  omeg  = 2.*pi/daysec
  g     = 9.8
  kappa = 0.2857143
  cpp   = 1004.70885
  dtvr  = daysec/FLOAT(day_step)
  CALL inigeom

!--- Beware: anneeref (from gcm.def) is used to determine output time sampling
  ndays=ioget_year_len(anneeref)

!--- RUGOSITY TREATMENT --------------------------------------------------------
  WRITE(lunout,*) 'Traitement de la rugosite'
  CALL get_2Dfield(frugo,'RUG',interbar,ndays,phy_rug,mask=masque(1:iim,:))

!--- OCEAN TREATMENT -----------------------------------------------------------
  PRINT*, 'Traitement de la glace oceanique' ; icefile=''; lCPL=.FALSE.

! Input SIC file selection
  icefile='fake'
  IF(NF90_OPEN(famipsic,NF90_NOWRITE,nid)==NF90_NOERR) icefile=TRIM(famipsic)
  IF(NF90_OPEN(fclimsic,NF90_NOWRITE,nid)==NF90_NOERR) icefile=TRIM(fclimsic)
  IF(NF90_OPEN(fcpldsic,NF90_NOWRITE,nid)==NF90_NOERR) icefile=TRIM(fcpldsic)
  SELECT CASE(icefile)
    CASE(famipsic); dumstr='Amip.'
    CASE(fclimsic); dumstr='Amip climatologique.'
    CASE(fcpldsic); dumstr='de sortie du modele couplé IPSL/IPCC.';lCPL=.TRUE.
    CASE('fake');   CALL abort_gcm('limit_netcdf','Fichier SIC non reconnu.',1)
  END SELECT
  ierr=NF90_CLOSE(nid)
  WRITE(lunout,*)'Pour la glace de mer a ete choisi un fichier '//TRIM(dumstr)

  CALL get_2Dfield(icefile,'SIC',interbar,ndays,phy_ice,flag=oldice,lCPL=lCPL)

  ALLOCATE(pctsrf_t(klon,nbsrf,ndays))
  DO k=1,ndays
    fi_ice=phy_ice(:,k)
    WHERE(fi_ice>=1.0  ) fi_ice=1.0
    WHERE(fi_ice<EPSFRA) fi_ice=0.0
    IF(fracterre) THEN
      pctsrf_t(:,is_ter,k)=pctsrf(:,is_ter)       ! land soil
      pctsrf_t(:,is_lic,k)=pctsrf(:,is_lic)       ! land ice
      IF(lCPL) THEN                               ! SIC=pICE*(1-LIC-TER)
        pctsrf_t(:,is_sic,k)=fi_ice*(1-pctsrf(:,is_lic)-pctsrf(:,is_ter))
      ELSE                                        ! SIC=pICE-LIC
        pctsrf_t(:,is_sic,k)=fi_ice-pctsrf_t(:,is_lic,k)
      END IF
      WHERE(pctsrf_t(:,is_sic,k)<=0) pctsrf_t(:,is_sic,k)=0.
      WHERE(1.0-zmasq<EPSFRA)
        pctsrf_t(:,is_sic,k)=0.0
        pctsrf_t(:,is_oce,k)=0.0
      ELSEWHERE
        WHERE(pctsrf_t(:,is_sic,k)>=1.0-zmasq)
          pctsrf_t(:,is_sic,k)=1.0-zmasq
          pctsrf_t(:,is_oce,k)=0.0
        ELSEWHERE
          pctsrf_t(:,is_oce,k)=1.0-zmasq-pctsrf_t(:,is_sic,k)
          WHERE(pctsrf_t(:,is_oce,k)<EPSFRA)
            pctsrf_t(:,is_oce,k)=0.0
            pctsrf_t(:,is_sic,k)=1.0-zmasq
          END WHERE
        END WHERE
      END WHERE
      nbad=COUNT(pctsrf_t(:,is_oce,k)<0.0)
      IF(nbad>0) WRITE(lunout,*) 'pb sous maille pour nb point = ',nbad
      nbad=COUNT(abs(sum(pctsrf_t(:,:,k),dim=2)-1.0)>EPSFRA)
      IF(nbad>0) WRITE(lunout,*) 'pb sous surface pour nb points = ',nbad
    ELSE 
      pctsrf_t(:,is_ter,k)=pctsrf(:,is_ter)
      WHERE(NINT(pctsrf(:,is_ter))==1)
        pctsrf_t(:,is_sic,k)=0.
        pctsrf_t(:,is_oce,k)=0.                  
        WHERE(fi_ice>=1.e-5)
          pctsrf_t(:,is_lic,k)=fi_ice
          pctsrf_t(:,is_ter,k)=pctsrf_t(:,is_ter,k)-pctsrf_t(:,is_lic,k)
        ELSEWHERE
          pctsrf_t(:,is_lic,k)=0.0
        END WHERE
      ELSEWHERE
        pctsrf_t(:,is_lic,k) = 0.0 
        WHERE(fi_ice>=1.e-5)
          pctsrf_t(:,is_ter,k)=0.0
          pctsrf_t(:,is_sic,k)=fi_ice
          pctsrf_t(:,is_oce,k)=1.0-pctsrf_t(:,is_sic,k)
        ELSEWHERE
          pctsrf_t(:,is_sic,k)=0.0
          pctsrf_t(:,is_oce,k)=1.0
        END WHERE
      END WHERE
      verif=sum(pctsrf_t(:,:,k),dim=2)
      nbad=COUNT(verif<1.0-1.e-5.OR.verif>1.0+1.e-5)
      IF(nbad>0) WRITE(lunout,*) 'pb sous maille pour nb point = ',nbad
    END IF 
  END DO
  DEALLOCATE(phy_ice)

!--- SST TREATMENT -------------------------------------------------------------
  WRITE(lunout,*) 'Traitement de la sst' ; sstfile=''; lCPL=.FALSE.

! Input SST file selection
  sstfile='fake'
  IF(NF90_OPEN(famipsst,NF90_NOWRITE,nid)==NF90_NOERR) sstfile=TRIM(famipsst)
  IF(NF90_OPEN(fclimsst,NF90_NOWRITE,nid)==NF90_NOERR) sstfile=TRIM(fclimsst)
  IF(NF90_OPEN(fcpldsst,NF90_NOWRITE,nid)==NF90_NOERR) sstfile=TRIM(fcpldsst)
  SELECT CASE(icefile)
    CASE(famipsic); dumstr='Amip.'
    CASE(fclimsic); dumstr='Amip climatologique.'
    CASE(fcpldsic); dumstr='de sortie du modele couplé IPSL/IPCC.';lCPL=.TRUE.
    CASE('fake');   CALL abort_gcm('limit_netcdf','Fichier SST non reconnu',1)
  END SELECT
  ierr=NF90_CLOSE(nid)
  WRITE(lunout,*)'Pour la temperature de mer a ete choisi un fichier '//TRIM(dumstr)

  CALL get_2Dfield(trim(sstfile),'SST',interbar,ndays,phy_sst,flag=extrap)

!--- ALBEDO TREATMENT ----------------------------------------------------------
  WRITE(lunout,*) 'Traitement de l albedo'
  CALL get_2Dfield(falbe,'ALB',interbar,ndays,phy_alb)

!--- REFERENCE GROUND HEAT FLUX TREATMENT --------------------------------------
  ALLOCATE(phy_bil(klon,ndays)); phy_bil=0.0

!--- OUTPUT FILE WRITING -------------------------------------------------------
  WRITE(lunout,*) 'Ecriture du fichier limit'

  !--- File creation
  ierr=NF90_CREATE("limit.nc",NF90_CLOBBER,nid)
  ierr=NF90_PUT_ATT(nid,NF90_GLOBAL,"title","Fichier conditions aux limites")

  !--- Dimensions creation
  ierr=NF90_DEF_DIM(nid,"points_physiques",klon,ndim)
  ierr=NF90_DEF_DIM(nid,"time",NF90_UNLIMITED,ntim)

  dims=(/ndim,ntim/)

  !--- Variables creation
  ierr=NF90_DEF_VAR(nid,"TEMPS",NF90_FORMAT,(/ntim/),id_tim)
  ierr=NF90_DEF_VAR(nid,"FOCE", NF90_FORMAT,dims,id_FOCE)
  ierr=NF90_DEF_VAR(nid,"FSIC", NF90_FORMAT,dims,id_FSIC)
  ierr=NF90_DEF_VAR(nid,"FTER", NF90_FORMAT,dims,id_FTER)
  ierr=NF90_DEF_VAR(nid,"FLIC", NF90_FORMAT,dims,id_FLIC)
  ierr=NF90_DEF_VAR(nid,"SST",  NF90_FORMAT,dims,id_SST)
  ierr=NF90_DEF_VAR(nid,"BILS", NF90_FORMAT,dims,id_BILS)
  ierr=NF90_DEF_VAR(nid,"ALB",  NF90_FORMAT,dims,id_ALB)
  ierr=NF90_DEF_VAR(nid,"RUG",  NF90_FORMAT,dims,id_RUG)

  !--- Attributes creation
  ierr=NF90_PUT_ATT(nid,id_tim, "title","Jour dans l annee")
  ierr=NF90_PUT_ATT(nid,id_FOCE,"title","Fraction ocean")
  ierr=NF90_PUT_ATT(nid,id_FSIC,"title","Fraction glace de mer")
  ierr=NF90_PUT_ATT(nid,id_FTER,"title","Fraction terre")
  ierr=NF90_PUT_ATT(nid,id_FLIC,"title","Fraction land ice")
  ierr=NF90_PUT_ATT(nid,id_SST ,"title","Temperature superficielle de la mer")
  ierr=NF90_PUT_ATT(nid,id_BILS,"title","Reference flux de chaleur au sol")
  ierr=NF90_PUT_ATT(nid,id_ALB, "title","Albedo a la surface")
  ierr=NF90_PUT_ATT(nid,id_RUG, "title","Rugosite")

  ierr=NF90_ENDDEF(nid)

  !--- Variables saving
  ierr=NF90_PUT_VAR(nid,id_tim,(/(REAL(k),k=1,ndays)/))
  ierr=NF90_PUT_VAR(nid,id_FOCE,pctsrf_t(:,is_oce,:),(/1,1/),(/klon,ndays/))
  ierr=NF90_PUT_VAR(nid,id_FSIC,pctsrf_t(:,is_sic,:),(/1,1/),(/klon,ndays/))
  ierr=NF90_PUT_VAR(nid,id_FTER,pctsrf_t(:,is_ter,:),(/1,1/),(/klon,ndays/))
  ierr=NF90_PUT_VAR(nid,id_FLIC,pctsrf_t(:,is_lic,:),(/1,1/),(/klon,ndays/))
  ierr=NF90_PUT_VAR(nid,id_SST ,phy_sst(:,:),(/1,1/),(/klon,ndays/))
  ierr=NF90_PUT_VAR(nid,id_BILS,phy_bil(:,:),(/1,1/),(/klon,ndays/))
  ierr=NF90_PUT_VAR(nid,id_ALB ,phy_alb(:,:),(/1,1/),(/klon,ndays/))
  ierr=NF90_PUT_VAR(nid,id_RUG ,phy_rug(:,:),(/1,1/),(/klon,ndays/))

  ierr=NF90_CLOSE(nid)

  DEALLOCATE(pctsrf_t,phy_sst,phy_bil,phy_alb,phy_rug)
#endif
! of #ifdef CPP_EARTH


!===============================================================================
!
  CONTAINS
!
!===============================================================================


!-------------------------------------------------------------------------------
!
SUBROUTINE get_2Dfield(fnam, mode, ibar, ndays, champo, flag, mask, lCPL)
!
!-----------------------------------------------------------------------------
! Comments:
!   There are two assumptions concerning the NetCDF files, that are satisfied
!   with files that are conforming NC convention:
!     1) The last dimension of the variables used is the time record.
!     2) Dimensional variables have the same names as corresponding dimensions.
!-----------------------------------------------------------------------------
  USE netcdf, ONLY: NF90_OPEN, NF90_INQ_VARID, NF90_INQUIRE_VARIABLE, &
       NF90_CLOSE, NF90_INQ_DIMID, NF90_INQUIRE_DIMENSION, NF90_GET_VAR, &
       NF90_GET_ATT
  USE dimphy, ONLY : klon
  USE phys_state_var_mod, ONLY : pctsrf
  USE control_mod
  use pchsp_95_m, only: pchsp_95
  use pchfe_95_m, only: pchfe_95
  use arth_m, only: arth

  IMPLICIT NONE
#include "dimensions.h"
#include "paramet.h"
#include "comgeom2.h"
#include "indicesol.h"
#include "iniprint.h"
!-----------------------------------------------------------------------------
! Arguments:
  CHARACTER(LEN=*),  INTENT(IN)     :: fnam     ! NetCDF file name
  CHARACTER(LEN=3),  INTENT(IN)     :: mode     ! RUG, SIC, SST or ALB
  LOGICAL,           INTENT(IN)     :: ibar     ! interp on pressure levels
  INTEGER,           INTENT(IN)     :: ndays    ! current year number of days
  REAL,    POINTER,  DIMENSION(:, :) :: champo   ! output field = f(t)
  LOGICAL, OPTIONAL, INTENT(IN)     :: flag     ! extrapol. (SST) old ice (SIC)
  REAL,    OPTIONAL, DIMENSION(iim, jjp1), INTENT(IN) :: mask
  LOGICAL, OPTIONAL, INTENT(IN)     :: lCPL     ! Coupled model flag (for ICE)
!------------------------------------------------------------------------------
! Local variables:
!--- NetCDF
  INTEGER :: ncid, varid                  ! NetCDF identifiers
  CHARACTER(LEN=30)               :: dnam       ! dimension name
  CHARACTER(LEN=80)               :: varname    ! NetCDF variable name
!--- dimensions
  INTEGER,           DIMENSION(4) :: dids       ! NetCDF dimensions identifiers
  REAL, ALLOCATABLE, DIMENSION(:) :: dlon_ini   ! initial longitudes vector
  REAL, ALLOCATABLE, DIMENSION(:) :: dlat_ini   ! initial latitudes  vector
  REAL, POINTER,     DIMENSION(:) :: dlon, dlat ! reordered lon/lat  vectors
!--- fields
  INTEGER :: imdep, jmdep, lmdep                ! dimensions of 'champ'
  REAL, ALLOCATABLE, DIMENSION(:, :) :: champ   ! wanted field on initial grid
  REAL, ALLOCATABLE, DIMENSION(:) :: yder, timeyear
  REAL,              DIMENSION(iim, jjp1) :: champint   ! interpolated field
  REAL, ALLOCATABLE, DIMENSION(:, :, :)    :: champtime
  REAL, ALLOCATABLE, DIMENSION(:, :, :)    :: champan
!--- input files
  CHARACTER(LEN=20)                 :: cal_in   ! calendar
  INTEGER                           :: ndays_in ! number of days
!--- misc
  INTEGER :: i, j, k, l                         ! loop counters
  REAL, ALLOCATABLE, DIMENSION(:, :) :: work     ! used for extrapolation
  CHARACTER(LEN=25)                 :: title    ! for messages
  LOGICAL                           :: extrp    ! flag for extrapolation
  REAL                              :: chmin, chmax
  INTEGER ierr
  integer n_extrap ! number of extrapolated points
  logical skip
!------------------------------------------------------------------------------
!---Variables depending on keyword 'mode' -------------------------------------
  NULLIFY(champo)
  SELECT CASE(mode)
    CASE('RUG'); varname='RUGOS';  title='Rugosite'
    CASE('SIC'); varname='sicbcs'; title='Sea-ice'
    CASE('SST'); varname='tosbcs'; title='SST'
    CASE('ALB'); varname='ALBEDO'; title='Albedo'
  END SELECT
  extrp=.FALSE. 
  IF ( PRESENT(flag) ) THEN 
    IF ( flag .AND. mode=='SST' ) extrp=.TRUE. 
  END IF

!--- GETTING SOME DIMENSIONAL VARIABLES FROM FILE -----------------------------
  ierr=NF90_OPEN(fnam, NF90_NOWRITE, ncid);             CALL ncerr(ierr, fnam)
  ierr=NF90_INQ_VARID(ncid, varname, varid);            CALL ncerr(ierr, fnam)
  ierr=NF90_INQUIRE_VARIABLE(ncid, varid, dimids=dids); CALL ncerr(ierr, fnam)

!--- Longitude
  ierr=NF90_INQUIRE_DIMENSION(ncid, dids(1), name=dnam, len=imdep)
  CALL ncerr(ierr, fnam); ALLOCATE(dlon_ini(imdep), dlon(imdep))
  ierr=NF90_INQ_VARID(ncid, dnam, varid);                CALL ncerr(ierr, fnam)
  ierr=NF90_GET_VAR(ncid, varid, dlon_ini);              CALL ncerr(ierr, fnam)
  WRITE(lunout, *) 'variable ', dnam, 'dimension ', imdep

!--- Latitude
  ierr=NF90_INQUIRE_DIMENSION(ncid, dids(2), name=dnam, len=jmdep)
  CALL ncerr(ierr, fnam); ALLOCATE(dlat_ini(jmdep), dlat(jmdep))
  ierr=NF90_INQ_VARID(ncid, dnam, varid);                CALL ncerr(ierr, fnam)
  ierr=NF90_GET_VAR(ncid, varid, dlat_ini);              CALL ncerr(ierr, fnam)
  WRITE(lunout, *) 'variable ', dnam, 'dimension ', jmdep

!--- Time (variable is not needed - it is rebuilt - but calendar is)
  ierr=NF90_INQUIRE_DIMENSION(ncid, dids(3), name=dnam, len=lmdep)
  CALL ncerr(ierr, fnam); ALLOCATE(timeyear(lmdep))
  ierr=NF90_INQ_VARID(ncid, dnam, varid);                CALL ncerr(ierr, fnam)
  cal_in=' '
  ierr=NF90_GET_ATT(ncid, varid, 'calendar', cal_in)
  IF(ierr/=NF90_NOERR) THEN
    SELECT CASE(mode)
      CASE('RUG', 'ALB'); cal_in='360d'
      CASE('SIC', 'SST'); cal_in='gregorian'
    END SELECT
    WRITE(lunout, *)'ATTENTION: variable "time" sans attribut "calendrier" ' &
         // 'dans '//TRIM(fnam)//'. On choisit la valeur par defaut.'
  END IF
  WRITE(lunout, *) 'variable ', dnam, 'dimension ', lmdep, 'calendrier ', &
       cal_in

!--- CONSTRUCTING THE INPUT TIME VECTOR FOR INTERPOLATION --------------------
  !--- Determining input file number of days, depending on calendar
  ndays_in=year_len(anneeref, cal_in)

!--- Time vector reconstruction (time vector from file is not trusted)
!--- If input records are not monthly, time sampling has to be constant !
  timeyear=mid_months(anneeref, cal_in, lmdep)
  IF (lmdep /= 12) WRITE(lunout, '(a, i3, a)') 'Note : les fichiers de ' &
       // TRIM(mode) // ' ne comportent pas 12, mais ', lmdep, &
       ' enregistrements.'

!--- GETTING THE FIELD AND INTERPOLATING IT ----------------------------------
  ALLOCATE(champ(imdep, jmdep), champtime(iim, jjp1, lmdep))
  IF(extrp) ALLOCATE(work(imdep, jmdep))

  WRITE(lunout, *)
  WRITE(lunout, '(a, i3, a)')'LECTURE ET INTERPOLATION HORIZ. DE ', lmdep, &
       ' CHAMPS.'
  ierr=NF90_INQ_VARID(ncid, varname, varid);             CALL ncerr(ierr, fnam)
  DO l=1, lmdep
    ierr=NF90_GET_VAR(ncid, varid, champ, (/1, 1, l/), (/imdep, jmdep, 1/))
    CALL ncerr(ierr, fnam)
    CALL conf_dat2d(title, imdep, jmdep, dlon_ini, dlat_ini, dlon, dlat, &
         champ, ibar)

    IF (extrp) CALL extrapol(champ, imdep, jmdep, 999999., .TRUE., .TRUE., 2, &
         work)

    IF(ibar.AND..NOT.(mode=='SIC'.AND.flag)) THEN
      IF(l==1) THEN
        WRITE(lunout, *)                                                      &
  '-------------------------------------------------------------------------'
        WRITE(lunout, *)                                                     &
  'Utilisation de l''interpolation barycentrique pour '//TRIM(title)//' $$$'
        WRITE(lunout, *)                                                      &
  '-------------------------------------------------------------------------'
      END IF
      IF(mode=='RUG') champ=LOG(champ)
      CALL inter_barxy(dlon, dlat(:jmdep-1), champ, rlonu(:iim),     &
                         rlatv, champint)
      IF(mode=='RUG') THEN
        champint=EXP(champint)
        WHERE(NINT(mask)/=1) champint=0.001
      END IF
    ELSE
      SELECT CASE(mode)
        CASE('RUG');       CALL rugosite(imdep, jmdep, dlon, dlat, champ,    &
                                    iim, jjp1, rlonv, rlatu, champint, mask)
        CASE('SIC');       CALL sea_ice (imdep, jmdep, dlon, dlat, champ,    &
                                    iim, jjp1, rlonv, rlatu, champint)
        CASE('SST', 'ALB'); CALL grille_m(imdep, jmdep, dlon, dlat, champ,    &
                                    iim, jjp1, rlonv, rlatu, champint)
      END SELECT
    END IF
    champtime(:, :, l)=champint
  END DO
  ierr=NF90_CLOSE(ncid);                                 CALL ncerr(ierr, fnam)

  DEALLOCATE(dlon_ini, dlat_ini, dlon, dlat, champ)
  IF(extrp) DEALLOCATE(work)

!--- TIME INTERPOLATION ------------------------------------------------------
  WRITE(lunout, *)
  WRITE(lunout, *)'INTERPOLATION TEMPORELLE.'
  WRITE(lunout, "(2x, ' Vecteur temps en entree: ', 10f6.1)") timeyear
  WRITE(lunout, "(2x, ' Vecteur temps en sortie de 0 a ', i3)") ndays
  ALLOCATE(yder(lmdep), champan(iip1, jjp1, ndays))
  skip = .false.
  n_extrap = 0
  DO j=1, jjp1
    DO i=1, iim
      yder = pchsp_95(timeyear, champtime(i, j, :), ibeg=2, iend=2, &
           vc_beg=0., vc_end=0.)
      CALL pchfe_95(timeyear, champtime(i, j, :), yder, skip, &
           arth(0., real(ndays_in) / ndays, ndays), champan(i, j, :), ierr)
      if (ierr < 0) stop 1
      n_extrap = n_extrap + ierr
    END DO
  END DO
  if (n_extrap /= 0) then
     print *, "get_2Dfield pchfe_95: n_extrap = ", n_extrap
  end if
  champan(iip1, :, :)=champan(1, :, :)
  DEALLOCATE(yder, champtime, timeyear)

!--- Checking the result
  DO j=1, jjp1
    CALL minmax(iip1, champan(1, j, 10), chmin, chmax)
    WRITE(lunout, *)' '//TRIM(title)//' au temps 10 ', chmin, chmax, j
  END DO

!--- SPECIAL FILTER FOR SST: SST>271.38 --------------------------------------
  IF(mode=='SST') THEN
    WRITE(lunout, *) 'Filtrage de la SST: SST >= 271.38'
    WHERE(champan<271.38) champan=271.38
  END IF

!--- SPECIAL FILTER FOR SIC: 0.0<SIC<1.0 -------------------------------------
  IF(mode=='SIC') THEN
    WRITE(lunout, *) 'Filtrage de la SIC: 0.0 < Sea-ice < 1.0'
    IF(.NOT.lCPL) champan(:, :, :)=champan(:, :, :)/100.
    champan(iip1, :, :)=champan(1, :, :)
    WHERE(champan>1.0) champan=1.0
    WHERE(champan<0.0) champan=0.0
  END IF

!--- DYNAMICAL TO PHYSICAL GRID ----------------------------------------------
  ALLOCATE(champo(klon, ndays))
  DO k=1, ndays
    CALL gr_dyn_fi(1, iip1, jjp1, klon, champan(1, 1, k), champo(1, k))
  END DO
  DEALLOCATE(champan)

END SUBROUTINE get_2Dfield
!
!-------------------------------------------------------------------------------



!-------------------------------------------------------------------------------
!
FUNCTION year_len(y,cal_in)
!
!-------------------------------------------------------------------------------
  USE ioipsl, ONLY : ioget_calendar,ioconf_calendar,lock_calendar,ioget_year_len
  IMPLICIT NONE
!-------------------------------------------------------------------------------
! Arguments:
  INTEGER                       :: year_len
  INTEGER,           INTENT(IN) :: y
  CHARACTER(LEN=*),  INTENT(IN) :: cal_in
!-------------------------------------------------------------------------------
! Local variables:
  CHARACTER(LEN=20)             :: cal_out              ! calendar (for outputs)
!-------------------------------------------------------------------------------
!--- Getting the input calendar to reset at the end of the function
  CALL ioget_calendar(cal_out)

!--- Unlocking calendar and setting it to wanted one
  CALL lock_calendar(.FALSE.); CALL ioconf_calendar(TRIM(cal_in))

!--- Getting the number of days in this year
  year_len=ioget_year_len(y)

!--- Back to original calendar
  CALL lock_calendar(.FALSE.); CALL ioconf_calendar(TRIM(cal_out))

END FUNCTION year_len
!
!-------------------------------------------------------------------------------


!-------------------------------------------------------------------------------
!
FUNCTION mid_months(y,cal_in,nm)
!
!-------------------------------------------------------------------------------
  USE ioipsl, ONLY : ioget_calendar,ioconf_calendar,lock_calendar,ioget_mon_len
  IMPLICIT NONE
!-------------------------------------------------------------------------------
! Arguments:
  INTEGER,                INTENT(IN) :: y               ! year
  CHARACTER(LEN=*),       INTENT(IN) :: cal_in          ! calendar
  INTEGER,                INTENT(IN) :: nm              ! months/year number
  REAL,    DIMENSION(nm)             :: mid_months      ! mid-month times
!-------------------------------------------------------------------------------
! Local variables:
  CHARACTER(LEN=99)                  :: mess            ! error message
  CHARACTER(LEN=20)                  :: cal_out         ! calendar (for outputs)
  INTEGER, DIMENSION(nm)             :: mnth            ! months lengths (days)
  INTEGER                            :: m               ! months counter
  INTEGER                            :: nd              ! number of days
!-------------------------------------------------------------------------------
  nd=year_len(y,cal_in)

  IF(nm==12) THEN

  !--- Getting the input calendar to reset at the end of the function
    CALL ioget_calendar(cal_out)

  !--- Unlocking calendar and setting it to wanted one
    CALL lock_calendar(.FALSE.); CALL ioconf_calendar(TRIM(cal_in))

  !--- Getting the length of each month
    DO m=1,nm; mnth(m)=ioget_mon_len(y,m); END DO

  !--- Back to original calendar
    CALL lock_calendar(.FALSE.); CALL ioconf_calendar(TRIM(cal_out))

  ELSE IF(MODULO(nd,nm)/=0) THEN
    WRITE(mess,'(a,i3,a,i3,a)')'Unconsistent calendar: ',nd,' days/year, but ',&
      nm,' months/year. Months number should divide days number.'
    CALL abort_gcm('mid_months',TRIM(mess),1)

  ELSE
    mnth=(/(m,m=1,nm,nd/nm)/)
  END IF

!--- Mid-months times
  mid_months(1)=0.5*FLOAT(mnth(1))
  DO k=2,nm
    mid_months(k)=mid_months(k-1)+0.5*FLOAT(mnth(k-1)+mnth(k))
  END DO

END FUNCTION mid_months
!
!-------------------------------------------------------------------------------


!-------------------------------------------------------------------------------
!
SUBROUTINE ncerr(ncres,fnam)
!
!-------------------------------------------------------------------------------
! Purpose: NetCDF errors handling.
!-------------------------------------------------------------------------------
  USE netcdf, ONLY : NF90_NOERR, NF90_STRERROR
  IMPLICIT NONE
!-------------------------------------------------------------------------------
! Arguments:
  INTEGER,          INTENT(IN) :: ncres
  CHARACTER(LEN=*), INTENT(IN) :: fnam
!-------------------------------------------------------------------------------
#include "iniprint.h"
  IF(ncres/=NF90_NOERR) THEN
    WRITE(lunout,*)'Problem with file '//TRIM(fnam)//' in routine limit_netcdf.'
    CALL abort_gcm('limit_netcdf',NF90_STRERROR(ncres),1)
  END IF

END SUBROUTINE ncerr
!
!-------------------------------------------------------------------------------


END SUBROUTINE limit_netcdf