#include "cppdefs.h"
      MODULE def_dai_mod
#if defined FOUR_DVAR || defined ENKF_RESTART
!
!git $Id$
!svn $Id: def_dai.F 1151 2023-02-09 03:08:53Z arango $
!================================================== Hernan G. Arango ===
!  Copyright (c) 2002-2023 The ROMS/TOMS Group                         !
!    Licensed under a MIT/X style license                              !
!    See License_ROMS.md                                               !
!=======================================================================
!                                                                      !
!  This module creates Data Assimilation initial conditions (4D-Var    !
!  analysis) or Ensemble Kalman Filter (EnKF) restart file using       !
!  either the standard NetCDF library or the Parallel-IO (PIO)         !
!  library. It defines its dimensions, attributes, and variables.      !
!                                                                      !
!=======================================================================
!
      USE mod_param
      USE mod_parallel
# ifdef BIOLOGY
      USE mod_biology
# endif
# ifdef FOUR_DVAR
      USE mod_fourdvar
# endif
      USE mod_iounits
      USE mod_ncparam
      USE mod_scalars
# ifdef SEDIMENT
      USE mod_sediment
# endif
!
      USE def_dim_mod,  ONLY : def_dim
      USE def_info_mod, ONLY : def_info
      USE def_var_mod,  ONLY : def_var
      USE strings_mod,  ONLY : FoundError
      USE wrt_info_mod, ONLY : wrt_info
!
      implicit none
!
      PUBLIC  :: def_dai
      PRIVATE :: def_dai_nf90
# if defined PIO_LIB && defined DISTRIBUTE
      PRIVATE :: def_dai_pio
# endif
!
      CONTAINS
!
!***********************************************************************
      SUBROUTINE def_dai (ng)
!***********************************************************************
!
!  Imported variable declarations.
!
      integer, intent(in) :: ng
!
!  Local variable declarations.
!
      character (len=*), parameter :: MyFile =                          &
     &  __FILE__
!
!-----------------------------------------------------------------------
!  Create a new history file according to IO type.
!-----------------------------------------------------------------------
!
      SELECT CASE (DAI(ng)%IOtype)
        CASE (io_nf90)
          CALL def_dai_nf90 (ng)

# if defined PIO_LIB && defined DISTRIBUTE
        CASE (io_pio)
          CALL def_dai_pio (ng)
# endif
        CASE DEFAULT
          IF (Master) WRITE (stdout,10) DAI(ng)%IOtype
          exit_flag=3
      END SELECT
      IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN
!
  10  FORMAT (' DEF_DAI - Illegal output file type, io_type = ',i0,     &
     &        /,11x,'Check KeyWord ''OUT_LIB'' in ''roms.in''.')
!
      RETURN
      END SUBROUTINE def_dai
!
!***********************************************************************
      SUBROUTINE def_dai_nf90 (ng)
!***********************************************************************
!
      USE mod_netcdf
!
!  Imported variable declarations.
!
      integer, intent(in) :: ng
!
!  Local variable declarations.
!
      logical :: got_var(NV)
!
      integer, parameter :: Natt = 25

      integer :: i, j, itrc, nvd3, nvd4
      integer :: recdim, status, varid

      integer :: DimIDs(nDimID)
      integer :: t2dgrd(3), u2dgrd(3), v2dgrd(3)
# ifdef SOLVE3D
      integer :: t3dgrd(4), u3dgrd(4), v3dgrd(4), w3dgrd(4)
# endif
!
      real(r8) :: Aval(6)
!
      character (len=256)    :: ncname
      character (len=MaxLen) :: Vinfo(Natt)

      character (len=*), parameter :: MyFile =                          &
     &  __FILE__//", def_dai_nf90"
!
      SourceFile=MyFile
!
!-----------------------------------------------------------------------
!  Set and report file name.
!-----------------------------------------------------------------------
!
      IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN
      ncname=DAI(ng)%name
!
      IF (Master) THEN
        IF (LdefDAI(ng)) THEN
          WRITE (stdout,10) ng, TRIM(ncname)
        ELSE
          WRITE (stdout,20) ng, TRIM(ncname)
        END IF
      END IF
!
!=======================================================================
!  Create a new Data Assimilation initial/restart NetCDF file.
!=======================================================================
!
      DEFINE : IF (LdefDAI(ng)) THEN
        CALL netcdf_create (ng, iNLM, TRIM(ncname), DAI(ng)%ncid)
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) THEN
          IF (Master) WRITE (stdout,30) TRIM(ncname)
          RETURN
        END IF
!
!-----------------------------------------------------------------------
!  Define file dimensions.
!-----------------------------------------------------------------------
!
        DimIDs=0
!
        status=def_dim(ng, iNLM, DAI(ng)%ncid, ncname, 'xi_rho',        &
     &                 IOBOUNDS(ng)%xi_rho, DimIDs( 1))
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN

        status=def_dim(ng, iNLM, DAI(ng)%ncid, ncname, 'xi_u',          &
     &                 IOBOUNDS(ng)%xi_u, DimIDs( 2))
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN

        status=def_dim(ng, iNLM, DAI(ng)%ncid, ncname, 'xi_v',          &
     &                 IOBOUNDS(ng)%xi_v, DimIDs( 3))
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN

        status=def_dim(ng, iNLM, DAI(ng)%ncid, ncname, 'xi_psi',        &
     &                 IOBOUNDS(ng)%xi_psi, DimIDs( 4))
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN

        status=def_dim(ng, iNLM, DAI(ng)%ncid, ncname, 'eta_rho',       &
     &                 IOBOUNDS(ng)%eta_rho, DimIDs( 5))
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN

        status=def_dim(ng, iNLM, DAI(ng)%ncid, ncname, 'eta_u',         &
     &                 IOBOUNDS(ng)%eta_u, DimIDs( 6))
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN

        status=def_dim(ng, iNLM, DAI(ng)%ncid, ncname, 'eta_v',         &
     &                 IOBOUNDS(ng)%eta_v, DimIDs( 7))
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN

        status=def_dim(ng, iNLM, DAI(ng)%ncid, ncname, 'eta_psi',       &
     &                 IOBOUNDS(ng)%eta_psi, DimIDs( 8))
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN

# ifdef SOLVE3D
        status=def_dim(ng, iNLM, DAI(ng)%ncid, ncname, 'N',             &
     &                 N(ng), DimIDs( 9))
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN

        status=def_dim(ng, iNLM, DAI(ng)%ncid, ncname, 's_rho',         &
     &                 N(ng), DimIDs( 9))
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN

        status=def_dim(ng, iNLM, DAI(ng)%ncid, ncname, 's_w',           &
     &                 N(ng)+1, DimIDs(10))
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN

        status=def_dim(ng, iNLM, DAI(ng)%ncid, ncname, 'tracer',        &
     &                 NT(ng), DimIDs(11))
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN

#  ifdef SEDIMENT
        status=def_dim(ng, iNLM, DAI(ng)%ncid, ncname, 'NST',           &
     &                 NST, DimIDs(32))
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN

        status=def_dim(ng, iNLM, DAI(ng)%ncid, ncname, 'Nbed',          &
     &                 Nbed, DimIDs(16))
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN
#  endif
#  ifdef ECOSIM
        status=def_dim(ng, iNLM, DAI(ng)%ncid, ncname, 'Nbands',        &
     &                 NBands, DimIDs(33))
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN

        status=def_dim(ng, iNLM, DAI(ng)%ncid, ncname, 'Nphy',          &
     &                 Nphy, DimIDs(25))
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN

        status=def_dim(ng, iNLM, DAI(ng)%ncid, ncname, 'Nbac',          &
     &                 Nbac, DimIDs(26))
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN

        status=def_dim(ng, iNLM, DAI(ng)%ncid, ncname, 'Ndom',          &
     &                 Ndom, DimIDs(27))
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN

        status=def_dim(ng, iNLM, DAI(ng)%ncid, ncname, 'Nfec',          &
     &                 Nfec, DimIDs(28))
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN
#  endif
# endif

        status=def_dim(ng, iNLM, DAI(ng)%ncid, ncname, 'boundary',      &
     &                 4, DimIDs(14))
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN

#ifdef FOUR_DVAR
        status=def_dim(ng, iNLM, DAI(ng)%ncid, ncname, 'Nstate',        &
     &                 NstateVar(ng), DimIDs(29))
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN
#endif

        status=def_dim(ng, iNLM, DAI(ng)%ncid, ncname,                  &
     &                 TRIM(ADJUSTL(Vname(5,idtime))),                  &
     &                 nf90_unlimited, DimIDs(12))
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN

        recdim=DimIDs(12)
!
!  Set number of dimensions for output variables.
!
        nvd3=3
        nvd4=4
!
!  Define dimension vectors for staggered tracer type variables.
!
        t2dgrd(1)=DimIDs( 1)
        t2dgrd(2)=DimIDs( 5)
        t2dgrd(3)=DimIDs(12)
# ifdef SOLVE3D
        t3dgrd(1)=DimIDs( 1)
        t3dgrd(2)=DimIDs( 5)
        t3dgrd(3)=DimIDs( 9)
        t3dgrd(4)=DimIDs(12)
# endif
!
!  Define dimension vectors for staggered u-momentum type variables.
!
        u2dgrd(1)=DimIDs( 2)
        u2dgrd(2)=DimIDs( 6)
        u2dgrd(3)=DimIDs(12)
# ifdef SOLVE3D
        u3dgrd(1)=DimIDs( 2)
        u3dgrd(2)=DimIDs( 6)
        u3dgrd(3)=DimIDs( 9)
        u3dgrd(4)=DimIDs(12)
# endif
!
!  Define dimension vectors for staggered v-momentum type variables.
!
        v2dgrd(1)=DimIDs( 3)
        v2dgrd(2)=DimIDs( 7)
        v2dgrd(3)=DimIDs(12)
# ifdef SOLVE3D
        v3dgrd(1)=DimIDs( 3)
        v3dgrd(2)=DimIDs( 7)
        v3dgrd(3)=DimIDs( 9)
        v3dgrd(4)=DimIDs(12)
# endif
# ifdef SOLVE3D
!
!  Define dimension vector for staggered w-momentum type variables.
!
        w3dgrd(1)=DimIDs( 1)
        w3dgrd(2)=DimIDs( 5)
        w3dgrd(3)=DimIDs(10)
        w3dgrd(4)=DimIDs(12)
# endif
!
!  Initialize unlimited time record dimension.
!
        DAI(ng)%Rindex=0
!
!  Initialize local information variable arrays.
!
        DO i=1,Natt
          DO j=1,LEN(Vinfo(1))
            Vinfo(i)(j:j)=' '
          END DO
        END DO
        DO i=1,6
          Aval(i)=0.0_r8
        END DO
!
!-----------------------------------------------------------------------
!  Define time-recordless information variables.
!-----------------------------------------------------------------------
!
        CALL def_info (ng, iNLM, DAI(ng)%ncid, ncname, DimIDs)
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN

# ifdef SOLVE3D
!
!  Define time independent (unperturb) depths of RHO-points.
!
        Vinfo( 1)=Vname(1,idpthR)
        WRITE (Vinfo( 2),40) TRIM(Vname(2,idpthR))
        Vinfo( 3)=Vname(3,idpthR)
        Vinfo(11)='downwards'
        Vinfo(22)='coordinates'
        Aval(5)=REAL(Iinfo(1,idpthR,ng),r8)
        status=def_var(ng, iNLM, DAI(ng)%ncid, DAI(ng)%Vid(idpthR),     &
     &                 NF_FRST, nvd3, t3dgrd, Aval, Vinfo, ncname,      &
     &                 SetFillVal = .FALSE.)
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN
!
!  Define time independent (unperturb) depths of U-points.
!
        Vinfo( 1)=Vname(1,idpthU)
        WRITE (Vinfo( 2),40) TRIM(Vname(2,idpthU))
        Vinfo( 3)=Vname(3,idpthU)
        Vinfo(11)='downwards'
        Vinfo(22)='coordinates'
        Aval(5)=REAL(Iinfo(1,idpthU,ng),r8)
        status=def_var(ng, iNLM, DAI(ng)%ncid, DAI(ng)%Vid(idpthU),     &
     &                 NF_FRST, nvd3, u3dgrd, Aval, Vinfo, ncname,      &
     &                 SetFillVal = .FALSE.)
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN
!
!  Define time independent (unperturb) depths of V-points.
!
        Vinfo( 1)=Vname(1,idpthV)
        WRITE (Vinfo( 2),40) TRIM(Vname(2,idpthV))
        Vinfo( 3)=Vname(3,idpthV)
        Vinfo(11)='downwards'
        Vinfo(22)='coordinates'
        Aval(5)=REAL(Iinfo(1,idpthV,ng),r8)
        status=def_var(ng, iNLM, DAI(ng)%ncid, DAI(ng)%Vid(idpthV),     &
     &                 NF_FRST, nvd3, v3dgrd, Aval, Vinfo, ncname,      &
     &                 SetFillVal = .FALSE.)
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN
!
!  Define time independent (unperturb) depths of W-points.
!
        Vinfo( 1)=Vname(1,idpthW)
        WRITE (Vinfo( 2),40) TRIM(Vname(2,idpthW))
        Vinfo( 3)=Vname(3,idpthW)
        Vinfo(11)='downwards'
        Vinfo(22)='coordinates'
        Aval(5)=REAL(Iinfo(1,idpthW,ng),r8)
        status=def_var(ng, iNLM, DAI(ng)%ncid, DAI(ng)%Vid(idpthW),     &
     &                 NF_FRST, nvd3, w3dgrd, Aval, Vinfo, ncname,      &
     &                 SetFillVal = .FALSE.)
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN
# endif
!
!-----------------------------------------------------------------------
!  Define time-varying variables.
!-----------------------------------------------------------------------
!
!  Define model time.
!
        Vinfo( 1)=Vname(1,idtime)
        Vinfo( 2)=Vname(2,idtime)
        WRITE (Vinfo( 3),'(a,a)') 'seconds since ', TRIM(Rclock%string)
        Vinfo( 4)=TRIM(Rclock%calendar)
        Vinfo(14)=Vname(4,idtime)
        Vinfo(21)=Vname(6,idtime)
        status=def_var(ng, iNLM, DAI(ng)%ncid, DAI(ng)%Vid(idtime),     &
     &                 NF_TOUT, 1, (/recdim/), Aval, Vinfo, ncname,     &
     &                 SetParAccess = .TRUE.)
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN
!
!  Define free-surface.
!
        Vinfo( 1)=Vname(1,idFsur)
        Vinfo( 2)=Vname(2,idFsur)
        Vinfo( 3)=Vname(3,idFsur)
        Vinfo(14)=Vname(4,idFsur)
        Vinfo(16)=Vname(1,idtime)
        Vinfo(21)=Vname(6,idFsur)
        Vinfo(22)='coordinates'
        Aval(5)=REAL(Iinfo(1,idFsur,ng),r8)
        status=def_var(ng, iNLM, DAI(ng)%ncid, DAI(ng)%Vid(idFsur),     &
# ifdef WET_DRY
     &                 NF_FRST, nvd3, t2dgrd, Aval, Vinfo, ncname,      &
     &                 SetFillVal = .FALSE.)
# else
     &                 NF_FRST, nvd3, t2dgrd, Aval, Vinfo, ncname)

# endif
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN
!
!  Define 2D momentum in the XI-direction.
!
        Vinfo( 1)=Vname(1,idUbar)
        Vinfo( 2)=Vname(2,idUbar)
        Vinfo( 3)=Vname(3,idUbar)
        Vinfo(14)=Vname(4,idUbar)
        Vinfo(16)=Vname(1,idtime)
        Vinfo(21)=Vname(6,idUbar)
        Vinfo(22)='coordinates'
        Aval(5)=REAL(Iinfo(1,idUbar,ng),r8)
        status=def_var(ng, iNLM, DAI(ng)%ncid, DAI(ng)%Vid(idUbar),     &
     &                 NF_FRST, nvd3, u2dgrd, Aval, Vinfo, ncname)
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN
!
!  Define 2D momentum in the ETA-direction.
!
        Vinfo( 1)=Vname(1,idVbar)
        Vinfo( 2)=Vname(2,idVbar)
        Vinfo( 3)=Vname(3,idVbar)
        Vinfo(14)=Vname(4,idVbar)
        Vinfo(16)=Vname(1,idtime)
        Vinfo(21)=Vname(6,idVbar)
        Vinfo(22)='coordinates'
        Aval(5)=REAL(Iinfo(1,idVbar,ng),r8)
        status=def_var(ng, iNLM, DAI(ng)%ncid, DAI(ng)%Vid(idVbar),     &
     &                 NF_FRST, nvd3, v2dgrd, Aval, Vinfo, ncname)
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN

# ifdef SOLVE3D
!
!  Define 3D momentum component in the XI-direction.
!
        Vinfo( 1)=Vname(1,idUvel)
        Vinfo( 2)=Vname(2,idUvel)
        Vinfo( 3)=Vname(3,idUvel)
        Vinfo(14)=Vname(4,idUvel)
        Vinfo(16)=Vname(1,idtime)
        Vinfo(21)=Vname(6,idUvel)
        Vinfo(22)='coordinates'
        Aval(5)=REAL(Iinfo(1,idUvel,ng),r8)
        status=def_var(ng, iNLM, DAI(ng)%ncid, DAI(ng)%Vid(idUvel),     &
     &                 NF_FRST, nvd4, u3dgrd, Aval, Vinfo, ncname)
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN
!
!  Define 3D momentum component in the ETA-direction.
!
        Vinfo( 1)=Vname(1,idVvel)
        Vinfo( 2)=Vname(2,idVvel)
        Vinfo( 3)=Vname(3,idVvel)
        Vinfo(14)=Vname(4,idVvel)
        Vinfo(16)=Vname(1,idtime)
        Vinfo(21)=Vname(6,idVvel)
        Vinfo(22)='coordinates'
        Aval(5)=REAL(Iinfo(1,idVvel,ng),r8)
        status=def_var(ng, iNLM, DAI(ng)%ncid, DAI(ng)%Vid(idVvel),     &
     &                 NF_FRST, nvd4, v3dgrd, Aval, Vinfo, ncname)
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN
!
!  Define tracer type variables.
!
        DO itrc=1,NT(ng)
          Vinfo( 1)=Vname(1,idTvar(itrc))
          Vinfo( 2)=Vname(2,idTvar(itrc))
          Vinfo( 3)=Vname(3,idTvar(itrc))
          Vinfo(14)=Vname(4,idTvar(itrc))
          Vinfo(16)=Vname(1,idtime)
#  ifdef SEDIMENT
          DO i=1,NST
            IF (itrc.eq.idsed(i)) THEN
              WRITE (Vinfo(19),50) 1000.0_r8*Sd50(i,ng)
            END IF
          END DO
#  endif
          Vinfo(21)=Vname(6,idTvar(itrc))
          Vinfo(22)='coordinates'
          Aval(5)=REAL(r3dvar,r8)
          status=def_var(ng, iNLM, DAI(ng)%ncid, DAI(ng)%Tid(itrc),     &
     &                   NF_FRST, nvd4, t3dgrd, Aval, Vinfo, ncname)
          IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN
        END DO
!
!  Define vertical viscosity coefficient.
!
        Vinfo( 1)=Vname(1,idVvis)
        Vinfo( 2)=Vname(2,idVvis)
        Vinfo( 3)=Vname(3,idVvis)
        Vinfo(14)=Vname(4,idVvis)
        Vinfo(16)=Vname(1,idtime)
        Vinfo(21)=Vname(6,idVvis)
        Vinfo(22)='coordinates'
        Aval(5)=REAL(Iinfo(1,idVvis,ng),r8)
        status=def_var(ng, iNLM, DAI(ng)%ncid, DAI(ng)%Vid(idVvis),     &
     &                   NF_FRST, nvd4, w3dgrd, Aval, Vinfo, ncname,    &
     &                   SetFillVal = .FALSE.)
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN
!
!  Define vertical diffusion coefficient for potential temperature.
!
        Vinfo( 1)=Vname(1,idTdif)
        Vinfo( 2)=Vname(2,idTdif)
        Vinfo( 3)=Vname(3,idTdif)
        Vinfo(14)=Vname(4,idTdif)
        Vinfo(16)=Vname(1,idtime)
        Vinfo(21)=Vname(6,idTdif)
        Vinfo(22)='coordinates'
        Aval(5)=REAL(Iinfo(1,idTdif,ng),r8)
        status=def_var(ng, iNLM, DAI(ng)%ncid, DAI(ng)%Vid(idTdif),     &
     &                 NF_FRST, nvd4, w3dgrd, Aval, Vinfo, ncname,      &
     &                 SetFillVal = .FALSE.)
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN
#  ifdef SALINITY
!
!  Define vertical diffusion coefficient for salinity.
!
        Vinfo( 1)=Vname(1,idSdif)
        Vinfo( 2)=Vname(2,idSdif)
        Vinfo( 3)=Vname(3,idSdif)
        Vinfo(14)=Vname(4,idSdif)
        Vinfo(16)=Vname(1,idtime)
        Vinfo(21)=Vname(6,idSdif)
        Vinfo(22)='coordinates'
        Aval(5)=REAL(Iinfo(1,idSdif,ng),r8)
        status=def_var(ng, iNLM, DAI(ng)%ncid, DAI(ng)%Vid(idSdif),     &
     &                 NF_FRST, nvd4, w3dgrd, Aval, Vinfo, ncname,      &
     &                 SetFillVal = .FALSE.)
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN
#  endif
# endif
!
!-----------------------------------------------------------------------
!  Leave definition mode.
!-----------------------------------------------------------------------
!
        CALL netcdf_enddef (ng, iNLM, ncname, DAI(ng)%ncid)
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN
!
!-----------------------------------------------------------------------
!  Write out time-recordless, information variables.
!-----------------------------------------------------------------------
!
        CALL wrt_info (ng, iNLM, DAI(ng)%ncid, ncname)
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN

      END IF DEFINE
!
!=======================================================================
!  Open an existing Data Assimilation initial/restart file, check its
!  contents, and prepare for appending data.
!=======================================================================
!
      QUERY : IF (.not.LdefDAI(ng)) THEN
        ncname=DAI(ng)%name
!
!  Open restart file for read/write.
!
        CALL netcdf_open (ng, iNLM, ncname, 1, DAI(ng)%ncid)
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) THEN
          WRITE (stdout,60) TRIM(ncname)
          RETURN
        END IF
!
!  Inquire about the dimensions and check for consistency.
!
        CALL netcdf_check_dim (ng, iNLM, ncname,                        &
     &                         ncid = DAI(ng)%ncid)
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN
!
!  Inquire about the variables.
!
        CALL netcdf_inq_var (ng, iNLM, ncname,                          &
     &                       ncid = DAI(ng)%ncid)
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN
!
!  Initialize logical switches.
!
        DO i=1,NV
          got_var(i)=.FALSE.
        END DO
!
!  Scan variable list from input NetCDF and activate switches for
!  Data Assimilation initial/restart variables. Get variable IDs.
!
        DO i=1,n_var
          IF (TRIM(var_name(i)).eq.TRIM(Vname(1,idtime))) THEN
            got_var(idtime)=.TRUE.
            DAI(ng)%Vid(idtime)=var_id(i)
          ELSE IF (TRIM(var_name(i)).eq.TRIM(Vname(1,idFsur))) THEN
            got_var(idFsur)=.TRUE.
            DAI(ng)%Vid(idFsur)=var_id(i)
          ELSE IF (TRIM(var_name(i)).eq.TRIM(Vname(1,idUbar))) THEN
            got_var(idUbar)=.TRUE.
            DAI(ng)%Vid(idUbar)=var_id(i)
          ELSE IF (TRIM(var_name(i)).eq.TRIM(Vname(1,idVbar))) THEN
            got_var(idVbar)=.TRUE.
            DAI(ng)%Vid(idVbar)=var_id(i)
# ifdef SOLVE3D
          ELSE IF (TRIM(var_name(i)).eq.TRIM(Vname(1,idUvel))) THEN
            got_var(idUvel)=.TRUE.
            DAI(ng)%Vid(idUvel)=var_id(i)
          ELSE IF (TRIM(var_name(i)).eq.TRIM(Vname(1,idVvel))) THEN
            got_var(idVvel)=.TRUE.
            DAI(ng)%Vid(idVvel)=var_id(i)
          ELSE IF (TRIM(var_name(i)).eq.TRIM(Vname(1,idVvis))) THEN
            got_var(idVvis)=.TRUE.
            DAI(ng)%Vid(idVvis)=var_id(i)
          ELSE IF (TRIM(var_name(i)).eq.TRIM(Vname(1,idTdif))) THEN
            got_var(idTdif)=.TRUE.
            DAI(ng)%Vid(idTdif)=var_id(i)
          ELSE IF (TRIM(var_name(i)).eq.TRIM(Vname(1,idSdif))) THEN
            got_var(idSdif)=.TRUE.
            DAI(ng)%Vid(idSdif)=var_id(i)
# endif
          END IF
# ifdef SOLVE3D
          DO itrc=1,NT(ng)
            IF (TRIM(var_name(i)).eq.TRIM(Vname(1,idTvar(itrc)))) THEN
              got_var(idTvar(itrc))=.TRUE.
              DAI(ng)%Tid(itrc)=var_id(i)
            END IF
          END DO
# endif
        END DO
!
!  Check if initialization variables are available in input NetCDF
!  file.
!
        IF (.not.got_var(idtime)) THEN
          IF (Master) WRITE (stdout,70) TRIM(Vname(1,idtime)),          &
     &                                  TRIM(ncname)
          exit_flag=3
          RETURN
        END IF
        IF (.not.got_var(idFsur)) THEN
          IF (Master) WRITE (stdout,70) TRIM(Vname(1,idFsur)),          &
     &                                  TRIM(ncname)
          exit_flag=3
          RETURN
        END IF
        IF (.not.got_var(idUbar)) THEN
          IF (Master) WRITE (stdout,70) TRIM(Vname(1,idUbar)),          &
     &                                  TRIM(ncname)
          exit_flag=3
          RETURN
        END IF
        IF (.not.got_var(idVbar)) THEN
          IF (Master) WRITE (stdout,70) TRIM(Vname(1,idVbar)),          &
     &                                  TRIM(ncname)
          exit_flag=3
          RETURN
        END IF
# ifdef SOLVE3D
        IF (.not.got_var(idUvel)) THEN
          IF (Master) WRITE (stdout,70) TRIM(Vname(1,idUvel)),          &
     &                                  TRIM(ncname)
          exit_flag=3
          RETURN
        END IF
        IF (.not.got_var(idVvel)) THEN
          IF (Master) WRITE (stdout,70) TRIM(Vname(1,idVvel)),          &
     &                                  TRIM(ncname)
          exit_flag=3
          RETURN
        END IF
        DO itrc=1,NT(ng)
          IF (.not.got_var(idTvar(itrc))) THEN
            IF (Master) WRITE (stdout,70) TRIM(Vname(1,idTvar(itrc))),  &
     &                                    TRIM(ncname)
            exit_flag=3
            RETURN
          END IF
        END DO
        IF (.not.got_var(idVvis)) THEN
          IF (Master) WRITE (stdout,70) TRIM(Vname(1,idVvis)),          &
     &                                  TRIM(ncname)
          exit_flag=3
          RETURN
        END IF
        IF (.not.got_var(idTdif)) THEN
          IF (Master) WRITE (stdout,70) TRIM(Vname(1,idTdif)),          &
     &                                  TRIM(ncname)
          exit_flag=3
          RETURN
        END IF
#  ifdef SALINITY
        IF (.not.got_var(idSdif)) THEN
          IF (Master) WRITE (stdout,70) TRIM(Vname(1,idSdif)),          &
     &                                  TRIM(ncname)
          exit_flag=3
          RETURN
        END IF
#  endif
# endif
!
!  Set unlimited time record dimension to current value.
!
        DAI(ng)%Rindex=rec_size
      END IF QUERY
!
  10  FORMAT (/,2x,'DEF_DAI_NF90     - creating DA INI/RST file,',t56,  &
     &        'Grid ',i2.2,': ',a)
  20  FORMAT (/,2x,'DEF_DAI_NF90     - inquiring DA INI/RST file,',t56, &
     &        'Grid ',i2.2,': ',a)
  30  FORMAT (/,' DEF_DAI_NF90 - unable to create DA initial/restart',  &
     &        ' NetCDF file: ',a)
  40  FORMAT ('time independent',1x,a)
  50  FORMAT (1pe11.4,1x,'millimeter')
  60  FORMAT (/,' DEF_DAI_NF90 - unable to open DA initial/restart'     &
     &        ' NetCDF file: ',a)
  70  FORMAT (/,' DEF_DAI_NF90 - unable to find variable: ',a,2x,       &
     &        ' in DA initial/restart NetCDF file: ',a)
!
      RETURN
      END SUBROUTINE def_dai_nf90

# if defined PIO_LIB && defined DISTRIBUTE
!
!***********************************************************************
      SUBROUTINE def_dai_pio (ng)
!***********************************************************************
!
      USE mod_pio_netcdf
!
!  Imported variable declarations.
!
      integer, intent(in) :: ng
!
!  Local variable declarations.
!
      logical :: got_var(NV)
!
      integer, parameter :: Natt = 25

      integer :: i, j, itrc, nvd3, nvd4
      integer :: recdim, status

      integer :: DimIDs(nDimID)
      integer :: t2dgrd(3), u2dgrd(3), v2dgrd(3)
#  ifdef SOLVE3D
      integer :: t3dgrd(4), u3dgrd(4), v3dgrd(4), w3dgrd(4)
#  endif
!
      real(r8) :: Aval(6)
!
      character (len=256)    :: ncname
      character (len=MaxLen) :: Vinfo(Natt)

      character (len=*), parameter :: MyFile =                          &
     &  __FILE__//", def_dai_pio"
!
      SourceFile=MyFile
!
!-----------------------------------------------------------------------
!  Set and report file name.
!-----------------------------------------------------------------------
!
      IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN
      ncname=DAI(ng)%name
!
      IF (Master) THEN
        IF (LdefDAI(ng)) THEN
          WRITE (stdout,10) ng, TRIM(ncname)
        ELSE
          WRITE (stdout,20) ng, TRIM(ncname)
        END IF
      END IF
!
!=======================================================================
!  Create a new Data Assimilation initial/restart NetCDF file.
!=======================================================================
!
      DEFINE : IF (LdefDAI(ng)) THEN
        CALL pio_netcdf_create (ng, iNLM, TRIM(ncname), DAI(ng)%pioFile)
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) THEN
          IF (Master) WRITE (stdout,30) TRIM(ncname)
          RETURN
        END IF
!
!-----------------------------------------------------------------------
!  Define file dimensions.
!-----------------------------------------------------------------------
!
        DimIDs=0
!
        status=def_dim(ng, iNLM, DAI(ng)%pioFile, ncname, 'xi_rho',     &
     &                 IOBOUNDS(ng)%xi_rho, DimIDs( 1))
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN

        status=def_dim(ng, iNLM, DAI(ng)%pioFile, ncname, 'xi_u',       &
     &                 IOBOUNDS(ng)%xi_u, DimIDs( 2))
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN

        status=def_dim(ng, iNLM, DAI(ng)%pioFile, ncname, 'xi_v',       &
     &                 IOBOUNDS(ng)%xi_v, DimIDs( 3))
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN

        status=def_dim(ng, iNLM, DAI(ng)%pioFile, ncname, 'xi_psi',     &
     &                 IOBOUNDS(ng)%xi_psi, DimIDs( 4))
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN

        status=def_dim(ng, iNLM, DAI(ng)%pioFile, ncname, 'eta_rho',    &
     &                 IOBOUNDS(ng)%eta_rho, DimIDs( 5))
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN

        status=def_dim(ng, iNLM, DAI(ng)%pioFile, ncname, 'eta_u',      &
     &                 IOBOUNDS(ng)%eta_u, DimIDs( 6))
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN

        status=def_dim(ng, iNLM, DAI(ng)%pioFile, ncname, 'eta_v',      &
     &                 IOBOUNDS(ng)%eta_v, DimIDs( 7))
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN

        status=def_dim(ng, iNLM, DAI(ng)%pioFile, ncname, 'eta_psi',    &
     &                 IOBOUNDS(ng)%eta_psi, DimIDs( 8))
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN

#  ifdef SOLVE3D
        status=def_dim(ng, iNLM, DAI(ng)%pioFile, ncname, 'N',          &
     &                 N(ng), DimIDs( 9))
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN

        status=def_dim(ng, iNLM, DAI(ng)%pioFile, ncname, 's_rho',      &
     &                 N(ng), DimIDs( 9))
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN

        status=def_dim(ng, iNLM, DAI(ng)%pioFile, ncname, 's_w',        &
     &                 N(ng)+1, DimIDs(10))
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN

        status=def_dim(ng, iNLM, DAI(ng)%pioFile, ncname, 'tracer',     &
     &                 NT(ng), DimIDs(11))
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN

#   ifdef SEDIMENT
        status=def_dim(ng, iNLM, DAI(ng)%pioFile, ncname, 'NST',        &
     &                 NST, DimIDs(32))
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN

        status=def_dim(ng, iNLM, DAI(ng)%pioFile, ncname, 'Nbed',       &
     &                 Nbed, DimIDs(16))
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN
#   endif
#   ifdef ECOSIM
        status=def_dim(ng, iNLM, DAI(ng)%pioFile, ncname, 'Nbands',     &
     &                 NBands, DimIDs(33))
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN

        status=def_dim(ng, iNLM, DAI(ng)%pioFile, ncname, 'Nphy',       &
     &                 Nphy, DimIDs(25))
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN

        status=def_dim(ng, iNLM, DAI(ng)%pioFile, ncname, 'Nbac',       &
     &                 Nbac, DimIDs(26))
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN

        status=def_dim(ng, iNLM, DAI(ng)%pioFile, ncname, 'Ndom',       &
     &                 Ndom, DimIDs(27))
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN

        status=def_dim(ng, iNLM, DAI(ng)%pioFile, ncname, 'Nfec',       &
     &                 Nfec, DimIDs(28))
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN
#   endif
#  endif

        status=def_dim(ng, iNLM, DAI(ng)%pioFile, ncname, 'boundary',   &
     &                 4, DimIDs(14))
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN

#  ifdef FOUR_DVAR
        status=def_dim(ng, iNLM, DAI(ng)%pioFile, ncname, 'Nstate',     &
     &                 NstateVar(ng), DimIDs(29))
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN
#  endif

        status=def_dim(ng, iNLM, DAI(ng)%pioFile, ncname,               &
     &                 TRIM(ADJUSTL(Vname(5,idtime))),                  &
     &                 PIO_unlimited, DimIDs(12))
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN

        recdim=DimIDs(12)
!
!  Set number of dimensions for output variables.
!
        nvd3=3
        nvd4=4
!
!  Define dimension vectors for staggered tracer type variables.
!
        t2dgrd(1)=DimIDs( 1)
        t2dgrd(2)=DimIDs( 5)
        t2dgrd(3)=DimIDs(12)
#  ifdef SOLVE3D
        t3dgrd(1)=DimIDs( 1)
        t3dgrd(2)=DimIDs( 5)
        t3dgrd(3)=DimIDs( 9)
        t3dgrd(4)=DimIDs(12)
#  endif
!
!  Define dimension vectors for staggered u-momentum type variables.
!
        u2dgrd(1)=DimIDs( 2)
        u2dgrd(2)=DimIDs( 6)
        u2dgrd(3)=DimIDs(12)
#  ifdef SOLVE3D
        u3dgrd(1)=DimIDs( 2)
        u3dgrd(2)=DimIDs( 6)
        u3dgrd(3)=DimIDs( 9)
        u3dgrd(4)=DimIDs(12)
#  endif
!
!  Define dimension vectors for staggered v-momentum type variables.
!
        v2dgrd(1)=DimIDs( 3)
        v2dgrd(2)=DimIDs( 7)
        v2dgrd(3)=DimIDs(12)
#  ifdef SOLVE3D
        v3dgrd(1)=DimIDs( 3)
        v3dgrd(2)=DimIDs( 7)
        v3dgrd(3)=DimIDs( 9)
        v3dgrd(4)=DimIDs(12)
#  endif
#  ifdef SOLVE3D
!
!  Define dimension vector for staggered w-momentum type variables.
!
        w3dgrd(1)=DimIDs( 1)
        w3dgrd(2)=DimIDs( 5)
        w3dgrd(3)=DimIDs(10)
        w3dgrd(4)=DimIDs(12)
#  endif
!
!  Initialize unlimited time record dimension.
!
        DAI(ng)%Rindex=0
!
!  Initialize local information variable arrays.
!
        DO i=1,Natt
          DO j=1,LEN(Vinfo(1))
            Vinfo(i)(j:j)=' '
          END DO
        END DO
        DO i=1,6
          Aval(i)=0.0_r8
        END DO
!
!-----------------------------------------------------------------------
!  Define time-recordless information variables.
!-----------------------------------------------------------------------
!
        CALL def_info (ng, iNLM, DAI(ng)%pioFile, ncname, DimIDs)
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN

#  ifdef SOLVE3D
!
!  Define time independent (unperturb) depths of RHO-points.
!
        Vinfo( 1)=Vname(1,idpthR)
        WRITE (Vinfo( 2),40) TRIM(Vname(2,idpthR))
        Vinfo( 3)=Vname(3,idpthR)
        Vinfo(11)='downwards'
        Vinfo(22)='coordinates'
        Aval(5)=REAL(Iinfo(1,idpthR,ng),r8)
        DAI(ng)%pioVar(idpthR)%dkind=PIO_FRST
        DAI(ng)%pioVar(idpthR)%gtype=r3dvar
!
        status=def_var(ng, iNLM, DAI(ng)%pioFile,                       &
     &                 DAI(ng)%pioVar(idpthR)%vd,                       &
     &                 PIO_FRST, nvd3, t3dgrd, Aval, Vinfo, ncname,     &
     &                 SetFillVal = .FALSE.)
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN
!
!  Define time independent (unperturb) depths of U-points.
!
        Vinfo( 1)=Vname(1,idpthU)
        WRITE (Vinfo( 2),40) TRIM(Vname(2,idpthU))
        Vinfo( 3)=Vname(3,idpthU)
        Vinfo(11)='downwards'
        Vinfo(22)='coordinates'
        Aval(5)=REAL(Iinfo(1,idpthU,ng),r8)
        DAI(ng)%pioVar(idpthU)%dkind=PIO_FRST
        DAI(ng)%pioVar(idpthU)%gtype=u3dvar
!
        status=def_var(ng, iNLM, DAI(ng)%pioFile,                       &
     &                 DAI(ng)%pioVar(idpthU)%vd,                       &
     &                 PIO_FRST, nvd3, u3dgrd, Aval, Vinfo, ncname,     &
     &                 SetFillVal = .FALSE.)
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN
!
!  Define time independent (unperturb) depths of V-points.
!
        Vinfo( 1)=Vname(1,idpthV)
        WRITE (Vinfo( 2),40) TRIM(Vname(2,idpthV))
        Vinfo( 3)=Vname(3,idpthV)
        Vinfo(11)='downwards'
        Vinfo(22)='coordinates'
        Aval(5)=REAL(Iinfo(1,idpthV,ng),r8)
        DAI(ng)%pioVar(idpthV)%dkind=PIO_FRST
        DAI(ng)%pioVar(idpthV)%gtype=v3dvar
!
        status=def_var(ng, iNLM, DAI(ng)%pioFile,                       &
     &                 DAI(ng)%pioVar(idpthV)%vd,                       &
     &                 PIO_FRST, nvd3, v3dgrd, Aval, Vinfo, ncname,     &
     &                 SetFillVal = .FALSE.)
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN
!
!  Define time independent (unperturb) depths of W-points.
!
        Vinfo( 1)=Vname(1,idpthW)
        WRITE (Vinfo( 2),40) TRIM(Vname(2,idpthW))
        Vinfo( 3)=Vname(3,idpthW)
        Vinfo(11)='downwards'
        Vinfo(22)='coordinates'
        Aval(5)=REAL(Iinfo(1,idpthW,ng),r8)
        DAI(ng)%pioVar(idpthW)%dkind=PIO_FRST
        DAI(ng)%pioVar(idpthW)%gtype=w3dvar
!
        status=def_var(ng, iNLM, DAI(ng)%pioFile,                       &
     &                 DAI(ng)%pioVar(idpthW)%vd,                       &
     &                 PIO_FRST, nvd3, w3dgrd, Aval, Vinfo, ncname,     &
     &                 SetFillVal = .FALSE.)
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN
#  endif
!
!-----------------------------------------------------------------------
!  Define time-varying variables.
!-----------------------------------------------------------------------
!
!  Define model time.
!
        Vinfo( 1)=Vname(1,idtime)
        Vinfo( 2)=Vname(2,idtime)
        WRITE (Vinfo( 3),'(a,a)') 'seconds since ', TRIM(Rclock%string)
        Vinfo( 4)=TRIM(Rclock%calendar)
        Vinfo(14)=Vname(4,idtime)
        Vinfo(21)=Vname(6,idtime)
        DAI(ng)%pioVar(idtime)%dkind=PIO_TOUT
        DAI(ng)%pioVar(idtime)%gtype=0
!
        status=def_var(ng, iNLM, DAI(ng)%pioFile,                       &
     &                 DAI(ng)%pioVar(idtime)%vd,                       &
     &                 PIO_TOUT, 1, (/recdim/), Aval, Vinfo, ncname,    &
     &                 SetParAccess = .TRUE.)
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN
!
!  Define free-surface.
!
        Vinfo( 1)=Vname(1,idFsur)
        Vinfo( 2)=Vname(2,idFsur)
        Vinfo( 3)=Vname(3,idFsur)
        Vinfo(14)=Vname(4,idFsur)
        Vinfo(16)=Vname(1,idtime)
        Vinfo(21)=Vname(6,idFsur)
        Vinfo(22)='coordinates'
        Aval(5)=REAL(Iinfo(1,idFsur,ng),r8)
        DAI(ng)%pioVar(idFsur)%dkind=PIO_FRST
        DAI(ng)%pioVar(idFsur)%gtype=r2dvar
!
        status=def_var(ng, iNLM, DAI(ng)%pioFile,                       &
     &                 DAI(ng)%pioVar(idFsur)%vd,                       &
#  ifdef WET_DRY
     &                 PIO_FRST, nvd3, t2dgrd, Aval, Vinfo, ncname,     &
     &                 SetFillVal = .FALSE.)
#  else
     &                 PIO_FRST, nvd3, t2dgrd, Aval, Vinfo, ncname)

#  endif
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN
!
!  Define 2D momentum in the XI-direction.
!
        Vinfo( 1)=Vname(1,idUbar)
        Vinfo( 2)=Vname(2,idUbar)
        Vinfo( 3)=Vname(3,idUbar)
        Vinfo(14)=Vname(4,idUbar)
        Vinfo(16)=Vname(1,idtime)
        Vinfo(21)=Vname(6,idUbar)
        Vinfo(22)='coordinates'
        Aval(5)=REAL(Iinfo(1,idUbar,ng),r8)
        DAI(ng)%pioVar(idUbar)%dkind=PIO_FRST
        DAI(ng)%pioVar(idUbar)%gtype=u2dvar
!
        status=def_var(ng, iNLM, DAI(ng)%pioFile,                       &
     &                 DAI(ng)%pioVar(idUbar)%vd,                       &
     &                 PIO_FRST, nvd3, u2dgrd, Aval, Vinfo, ncname)
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN
!
!  Define 2D momentum in the ETA-direction.
!
        Vinfo( 1)=Vname(1,idVbar)
        Vinfo( 2)=Vname(2,idVbar)
        Vinfo( 3)=Vname(3,idVbar)
        Vinfo(14)=Vname(4,idVbar)
        Vinfo(16)=Vname(1,idtime)
        Vinfo(21)=Vname(6,idVbar)
        Vinfo(22)='coordinates'
        Aval(5)=REAL(Iinfo(1,idVbar,ng),r8)
        DAI(ng)%pioVar(idVbar)%dkind=PIO_FRST
        DAI(ng)%pioVar(idVbar)%gtype=v2dvar
!
        status=def_var(ng, iNLM, DAI(ng)%pioFile,                       &
     &                 DAI(ng)%pioVar(idVbar)%vd,                       &
     &                 PIO_FRST, nvd3, v2dgrd, Aval, Vinfo, ncname)
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN

#  ifdef SOLVE3D
!
!  Define 3D momentum component in the XI-direction.
!
        Vinfo( 1)=Vname(1,idUvel)
        Vinfo( 2)=Vname(2,idUvel)
        Vinfo( 3)=Vname(3,idUvel)
        Vinfo(14)=Vname(4,idUvel)
        Vinfo(16)=Vname(1,idtime)
        Vinfo(21)=Vname(6,idUvel)
        Vinfo(22)='coordinates'
        Aval(5)=REAL(Iinfo(1,idUvel,ng),r8)
        DAI(ng)%pioVar(idUvel)%dkind=PIO_FRST
        DAI(ng)%pioVar(idUvel)%gtype=u3dvar
!
        status=def_var(ng, iNLM, DAI(ng)%pioFile,                       &
     &                 DAI(ng)%pioVar(idUvel)%vd,                       &
     &                 PIO_FRST, nvd4, u3dgrd, Aval, Vinfo, ncname)
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN
!
!  Define 3D momentum component in the ETA-direction.
!
        Vinfo( 1)=Vname(1,idVvel)
        Vinfo( 2)=Vname(2,idVvel)
        Vinfo( 3)=Vname(3,idVvel)
        Vinfo(14)=Vname(4,idVvel)
        Vinfo(16)=Vname(1,idtime)
        Vinfo(21)=Vname(6,idVvel)
        Vinfo(22)='coordinates'
        Aval(5)=REAL(Iinfo(1,idVvel,ng),r8)
        DAI(ng)%pioVar(idVvel)%dkind=PIO_FRST
        DAI(ng)%pioVar(idVvel)%gtype=v3dvar
!
        status=def_var(ng, iNLM, DAI(ng)%pioFile,                       &
     &                 DAI(ng)%pioVar(idVvel)%vd,                       &
     &                 PIO_FRST, nvd4, v3dgrd, Aval, Vinfo, ncname)
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN
!
!  Define tracer type variables.
!
        DO itrc=1,NT(ng)
          Vinfo( 1)=Vname(1,idTvar(itrc))
          Vinfo( 2)=Vname(2,idTvar(itrc))
          Vinfo( 3)=Vname(3,idTvar(itrc))
          Vinfo(14)=Vname(4,idTvar(itrc))
          Vinfo(16)=Vname(1,idtime)
#   ifdef SEDIMENT
          DO i=1,NST
            IF (itrc.eq.idsed(i)) THEN
              WRITE (Vinfo(19),50) 1000.0_r8*Sd50(i,ng)
            END IF
          END DO
#   endif
          Vinfo(21)=Vname(6,idTvar(itrc))
          Vinfo(22)='coordinates'
          Aval(5)=REAL(r3dvar,r8)
          DAI(ng)%pioTrc(itrc)%dkind=PIO_FRST
          DAI(ng)%pioTrc(itrc)%gtype=r3dvar
!
          status=def_var(ng, iNLM, DAI(ng)%pioFile,                     &
     &                   DAI(ng)%pioTrc(itrc)%vd,                       &
     &                   PIO_FRST, nvd4, t3dgrd, Aval, Vinfo, ncname)
          IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN
        END DO
!
!  Define vertical viscosity coefficient.
!
        Vinfo( 1)=Vname(1,idVvis)
        Vinfo( 2)=Vname(2,idVvis)
        Vinfo( 3)=Vname(3,idVvis)
        Vinfo(14)=Vname(4,idVvis)
        Vinfo(16)=Vname(1,idtime)
        Vinfo(21)=Vname(6,idVvis)
        Vinfo(22)='coordinates'
        Aval(5)=REAL(Iinfo(1,idVvis,ng),r8)
        DAI(ng)%pioVar(idVvis)%dkind=PIO_FRST
        DAI(ng)%pioVar(idVvis)%gtype=w3dvar
!
        status=def_var(ng, iNLM, DAI(ng)%pioFile,                       &
     &                 DAI(ng)%pioVar(idVvis)%vd,                       &
     &                   PIO_FRST, nvd4, w3dgrd, Aval, Vinfo, ncname,   &
     &                   SetFillVal = .FALSE.)
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN
!
!  Define vertical diffusion coefficient for potential temperature.
!
        Vinfo( 1)=Vname(1,idTdif)
        Vinfo( 2)=Vname(2,idTdif)
        Vinfo( 3)=Vname(3,idTdif)
        Vinfo(14)=Vname(4,idTdif)
        Vinfo(16)=Vname(1,idtime)
        Vinfo(21)=Vname(6,idTdif)
        Vinfo(22)='coordinates'
        Aval(5)=REAL(Iinfo(1,idTdif,ng),r8)
        DAI(ng)%pioVar(idTdif)%dkind=PIO_FRST
        DAI(ng)%pioVar(idTdif)%gtype=w3dvar
!
        status=def_var(ng, iNLM, DAI(ng)%pioFile,                       &
     &                 DAI(ng)%pioVar(idTdif)%vd,                       &
     &                 PIO_FRST, nvd4, w3dgrd, Aval, Vinfo, ncname,     &
     &                 SetFillVal = .FALSE.)
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN

#   ifdef SALINITY
!
!  Define vertical diffusion coefficient for salinity.
!
        Vinfo( 1)=Vname(1,idSdif)
        Vinfo( 2)=Vname(2,idSdif)
        Vinfo( 3)=Vname(3,idSdif)
        Vinfo(14)=Vname(4,idSdif)
        Vinfo(16)=Vname(1,idtime)
        Vinfo(21)=Vname(6,idSdif)
        Vinfo(22)='coordinates'
        Aval(5)=REAL(Iinfo(1,idSdif,ng),r8)
        DAI(ng)%pioVar(idSdif)%dkind=PIO_FRST
        DAI(ng)%pioVar(idSdif)%gtype=w3dvar
!
        status=def_var(ng, iNLM, DAI(ng)%pioFile,                       &
     &                 DAI(ng)%pioVar(idSdif)%vd,                       &
     &                 PIO_FRST, nvd4, w3dgrd, Aval, Vinfo, ncname,     &
     &                 SetFillVal = .FALSE.)
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN
#   endif
#  endif
!
!-----------------------------------------------------------------------
!  Leave definition mode.
!-----------------------------------------------------------------------
!
        CALL pio_netcdf_enddef (ng, iNLM, ncname, DAI(ng)%pioFile)
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN
!
!-----------------------------------------------------------------------
!  Write out time-recordless, information variables.
!-----------------------------------------------------------------------
!
        CALL wrt_info (ng, iNLM, DAI(ng)%pioFile, ncname)
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN

      END IF DEFINE
!
!=======================================================================
!  Open an existing Data Assimilation initial/restart file, check its
!  contents, and prepare for appending data.
!=======================================================================
!
      QUERY : IF (.not.LdefDAI(ng)) THEN
        ncname=DAI(ng)%name
!
!  Open restart file for read/write.
!
        CALL pio_netcdf_open (ng, iNLM, ncname, 1, DAI(ng)%pioFile)
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) THEN
          WRITE (stdout,60) TRIM(ncname)
          RETURN
        END IF
!
!  Inquire about the dimensions and check for consistency.
!
        CALL pio_netcdf_check_dim (ng, iNLM, ncname,                    &
     &                             pioFile = DAI(ng)%pioFile)
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN
!
!  Inquire about the variables.
!
        CALL pio_netcdf_inq_var (ng, iNLM, ncname,                      &
     &                           pioFile= DAI(ng)%pioFile)
        IF (FoundError(exit_flag, NoError, __LINE__, MyFile)) RETURN
!
!  Initialize logical switches.
!
        DO i=1,NV
          got_var(i)=.FALSE.
        END DO
!
!  Scan variable list from input NetCDF and activate switches for
!  Data Assimilation initial/restart variables. Get variable IDs.
!
        DO i=1,n_var
          IF (TRIM(var_name(i)).eq.TRIM(Vname(1,idtime))) THEN
            got_var(idtime)=.TRUE.
            DAI(ng)%pioVar(idtime)%vd=var_desc(i)
            DAI(ng)%pioVar(idtime)%dkind=PIO_TOUT
            DAI(ng)%pioVar(idtime)%gtype=0
          ELSE IF (TRIM(var_name(i)).eq.TRIM(Vname(1,idFsur))) THEN
            got_var(idFsur)=.TRUE.
            DAI(ng)%pioVar(idFsur)%vd=var_desc(i)
            DAI(ng)%pioVar(idFsur)%dkind=PIO_FRST
            DAI(ng)%pioVar(idFsur)%gtype=r2dvar
          ELSE IF (TRIM(var_name(i)).eq.TRIM(Vname(1,idUbar))) THEN
            got_var(idUbar)=.TRUE.
            DAI(ng)%pioVar(idUbar)%vd=var_desc(i)
            DAI(ng)%pioVar(idUbar)%dkind=PIO_FRST
            DAI(ng)%pioVar(idUbar)%gtype=u2dvar
          ELSE IF (TRIM(var_name(i)).eq.TRIM(Vname(1,idVbar))) THEN
            got_var(idVbar)=.TRUE.
            DAI(ng)%pioVar(idVbar)%vd=var_desc(i)
            DAI(ng)%pioVar(idVbar)%dkind=PIO_FRST
            DAI(ng)%pioVar(idVbar)%gtype=v2dvar
#  ifdef SOLVE3D
          ELSE IF (TRIM(var_name(i)).eq.TRIM(Vname(1,idUvel))) THEN
            got_var(idUvel)=.TRUE.
            DAI(ng)%pioVar(idUvel)%vd=var_desc(i)
            DAI(ng)%pioVar(idUvel)%dkind=PIO_FRST
            DAI(ng)%pioVar(idUvel)%gtype=u3dvar
          ELSE IF (TRIM(var_name(i)).eq.TRIM(Vname(1,idVvel))) THEN
            got_var(idVvel)=.TRUE.
            DAI(ng)%pioVar(idVvel)%vd=var_desc(i)
            DAI(ng)%pioVar(idVvel)%dkind=PIO_FRST
            DAI(ng)%pioVar(idVvel)%gtype=v3dvar
          ELSE IF (TRIM(var_name(i)).eq.TRIM(Vname(1,idVvis))) THEN
            got_var(idVvis)=.TRUE.
            DAI(ng)%pioVar(idVvis)%vd=var_desc(i)
            DAI(ng)%pioVar(idVvis)%dkind=PIO_FRST
            DAI(ng)%pioVar(idVvis)%gtype=w3dvar
          ELSE IF (TRIM(var_name(i)).eq.TRIM(Vname(1,idTdif))) THEN
            got_var(idTdif)=.TRUE.
            DAI(ng)%pioVar(idTdif)%vd=var_desc(i)
            DAI(ng)%pioVar(idTdif)%dkind=PIO_FRST
            DAI(ng)%pioVar(idTdif)%gtype=w3dvar
          ELSE IF (TRIM(var_name(i)).eq.TRIM(Vname(1,idSdif))) THEN
            got_var(idSdif)=.TRUE.
            DAI(ng)%pioVar(idSdif)%vd=var_desc(i)
            DAI(ng)%pioVar(idSdif)%dkind=PIO_FRST
            DAI(ng)%pioVar(idSdif)%gtype=w3dvar
#  endif
          END IF
#  ifdef SOLVE3D
          DO itrc=1,NT(ng)
            IF (TRIM(var_name(i)).eq.TRIM(Vname(1,idTvar(itrc)))) THEN
              got_var(idTvar(itrc))=.TRUE.
              DAI(ng)%pioTrc(itrc)%vd=var_desc(i)
              DAI(ng)%pioTrc(itrc)%dkind=PIO_FRST
              DAI(ng)%pioTrc(itrc)%gtype=r3dvar
            END IF
          END DO
#  endif
        END DO
!
!  Check if initialization variables are available in input NetCDF
!  file.
!
        IF (.not.got_var(idtime)) THEN
          IF (Master) WRITE (stdout,70) TRIM(Vname(1,idtime)),          &
     &                                  TRIM(ncname)
          exit_flag=3
          RETURN
        END IF
        IF (.not.got_var(idFsur)) THEN
          IF (Master) WRITE (stdout,70) TRIM(Vname(1,idFsur)),          &
     &                                  TRIM(ncname)
          exit_flag=3
          RETURN
        END IF
        IF (.not.got_var(idUbar)) THEN
          IF (Master) WRITE (stdout,70) TRIM(Vname(1,idUbar)),          &
     &                                  TRIM(ncname)
          exit_flag=3
          RETURN
        END IF
        IF (.not.got_var(idVbar)) THEN
          IF (Master) WRITE (stdout,70) TRIM(Vname(1,idVbar)),          &
     &                                  TRIM(ncname)
          exit_flag=3
          RETURN
        END IF
#  ifdef SOLVE3D
        IF (.not.got_var(idUvel)) THEN
          IF (Master) WRITE (stdout,70) TRIM(Vname(1,idUvel)),          &
     &                                  TRIM(ncname)
          exit_flag=3
          RETURN
        END IF
        IF (.not.got_var(idVvel)) THEN
          IF (Master) WRITE (stdout,70) TRIM(Vname(1,idVvel)),          &
     &                                  TRIM(ncname)
          exit_flag=3
          RETURN
        END IF
        DO itrc=1,NT(ng)
          IF (.not.got_var(idTvar(itrc))) THEN
            IF (Master) WRITE (stdout,70) TRIM(Vname(1,idTvar(itrc))),  &
     &                                    TRIM(ncname)
            exit_flag=3
            RETURN
          END IF
        END DO
        IF (.not.got_var(idVvis)) THEN
          IF (Master) WRITE (stdout,70) TRIM(Vname(1,idVvis)),          &
     &                                  TRIM(ncname)
          exit_flag=3
          RETURN
        END IF
        IF (.not.got_var(idTdif)) THEN
          IF (Master) WRITE (stdout,70) TRIM(Vname(1,idTdif)),          &
     &                                  TRIM(ncname)
          exit_flag=3
          RETURN
        END IF
#   ifdef SALINITY
        IF (.not.got_var(idSdif)) THEN
          IF (Master) WRITE (stdout,70) TRIM(Vname(1,idSdif)),          &
     &                                  TRIM(ncname)
          exit_flag=3
          RETURN
        END IF
#   endif
#  endif
!
!  Set unlimited time record dimension to current value.
!
        DAI(ng)%Rindex=rec_size
      END IF QUERY
!
  10  FORMAT (/,2x,'DEF_DAI_PIO      - creating DA INI/RST file,',t56,  &
     &        'Grid ',i2.2,': ',a)
  20  FORMAT (/,2x,'DEF_DAI_PIO      - inquiring DA INI/RST file,',t56, &
     &        'Grid ',i2.2,': ',a)
  30  FORMAT (/,' DEF_DAI_PIO - unable to create DA initial/restart',   &
     &        ' NetCDF file: ',a)
  40  FORMAT ('time independent',1x,a)
  50  FORMAT (1pe11.4,1x,'millimeter')
  60  FORMAT (/,' DEF_DAI_PIO - unable to open DA initial/restart'      &
     &        ' NetCDF file: ',a)
  70  FORMAT (/,' DEF_DAI_PIO - unable to find variable: ',a,2x,        &
     &        ' in DA initial/restart NetCDF file: ',a)
!
      RETURN
      END SUBROUTINE def_dai_pio
# endif
#endif
      END MODULE def_dai_mod