!
! Field types (will be components of history type, see below):
!
      integer,parameter :: mxflds=200,longname_len=80,shortname_len=16,
     |  units_len=16
!
      type field_3d
        character(len=longname_len)  :: long_name
        character(len=shortname_len) :: short_name
        character(len=units_len)     :: units
        real                         :: missing_value
        real,pointer :: data(:,:,:)  
        integer :: id1,id2,id3         ! usually nlon,nlat,nlev
        logical :: mag,geo             ! magnetic or geographic grid
        character(len=8) :: levdimname ! lev, ilev, mlev, or imlev
        character(len=8) :: type       ! "DENSITY" or blank
      end type field_3d
!
      type field_2d
        character(len=longname_len)  :: long_name
        character(len=shortname_len) :: short_name
        character(len=units_len)     :: units
        real                         :: missing_value
        real,pointer :: data(:,:)   
        integer :: id1,id2           ! usually nlon,nlat
        logical :: mag,geo
      end type field_2d
!
      type field_1d
        character(len=longname_len)  :: long_name
        character(len=shortname_len) :: short_name
        character(len=units_len)     :: units
        real                         :: missing_value
        real,pointer :: data(:)
        integer :: id1
      end type field_1d
!
! History structure type:
!
      integer,parameter :: mxlen=120
      type history
        character(len=mxlen) :: 
     |    history_file            ! Name of file containing this history
        character(len=mxlen) ::   ! text global attributes
     |    Conventions,
     |    label,
     |    create_date,
     |    logname,
     |    host,
     |    system,
     |    model_name,
     |    model_version,
     |    output_file,
     |    history_type,
     |    run_type,
     |    source_file,
     |    initial_file,
     |    lev_to_hPa_method1,
     |    lev_to_hPa_method2,
     |    potential_model,
     |    contents,
     |    contents_desc
        integer ::                   ! integer global attributes
     |    tuv_lbc_intop,
     |    delhist_mins,
     |    initial_mtime(3),
     |    source_mtime(3)
        real ::                    ! double global attributes
     |    missing_value
        character(len=mxlen) ::
     |    write_date,        ! date each history was written
     |    ncep_ncfile,       ! ncep lbc data file
     |    gpi_ncfile,        ! gpi lbc data file
     |    gswm_mi_di_ncfile, ! gswm migrating diurnal data file
     |    gswm_mi_sdi_ncfile,! gswm migrating semi-diurnal data file
     |    gswm_nm_di_ncfile, ! gswm non-migrating diurnal data file
     |    gswm_nm_sdi_ncfile,! gswm non-migrating semi-diurnal data file
     |    see_ncfile,        ! SEE data file
     |    imf_ncfile,        ! IMF data file
     |    ecmwf_ncfile       ! ECMWF boundary data file
        integer ::
     |    gswmdi,gswmsdi,gswmnmdi,gswmnmsdi
        integer ::
     |    nlat,              ! number of latitude grid points
     |    nlon,              ! number of longitude grid points
     |    nlev,              ! number of vertical levels
     |    nilev,             ! number of interface levels (nlev == nilev)
     |    nhist,             ! number of histories on the file (s.a.,nhist)
     |    mlon,mlat,mlev,    ! magnetic grid dimensions
     |    imlev,             ! number of mag interface levels
     |    ihist,             ! ihist = nth history on current file
     |    delhmins,          ! delta minutes between histories
     |    modeltime(4),      ! model time (day,hour,minute,seconds)
     |    iter,              ! iteration (# steps from 0,0,0)
     |    year,              ! 4-digit year
     |    day,               ! calendar day (1-367)
     |    calendar_advance,  ! calendar advance (0 or 1)
     |    step,              ! time step (seconds)
     |    ncep,              ! nmc/ncep flag (0 or 1)
     |    gpi,               ! gpi flag (0 or 1)
     |    datelen,
     |    filelen
        real ::
     |    ut,                ! ut (decimal hours, from modeltime)
     |    time,              ! model time ("minutes since yyyy-m-d")
     |    p0,                ! reference pressure
     |    p0_model,          ! reference pressure used in model
     |    hpower,            ! hemispheric power
     |    ctpoten,           ! cross-cap potential
     |    bximf,             ! bx imf
     |    byimf,             ! by imf
     |    bzimf,             ! bz imf
     |    f107d,             ! daily f10.7 cm flux
     |    f107a,             ! 81-day average f10.7 cm flux
     |    mag(2,2),          ! magnetic pole coordinates
     |    dtide(2),          ! diurnal tide (tide2(2) from input)
     |    sdtide(10),        ! semi-diurnal tide (tide(10) from input)
     |    colfac,            ! collision factor
     |    alfa30,e30,alfad2,ed2, ! auroral parameters ("old" hist)
     |    al,e1,e2,h1,h2,alfac,ec,alfad,ed, ! auroral parameters ("new" hist)
     |    swvel,swden,       ! solar wind velocity, density
     |    grav,              ! gravity constant
     |    lbc                ! lower interface boundary
        logical dynamo       ! if true, is dynamo history
        logical coupled_ccm  ! if true, run was coupled with ccm
        logical old,new
        character(len=16),pointer ::
     |    fnames3d_geo(:),   ! pointer to 3d geo field names
     |    fnames3d_mag(:),   ! pointer to 3d mag field names
     |    fnames2d_geo(:),   ! pointer to 2d geo field names
     |    fnames2d_mag(:)    ! pointer to 2d mag field names
!
! Coordinate variables:
        real,pointer :: glat(:),glon(:)       ! geographic lat lon grid
        real,pointer :: gmlat(:),gmlon(:)     ! geomagnetic lat lon grid
        real,pointer :: lev(:),ilev(:)        ! midpoint and interface geo levels 
        real,pointer :: gmlev(:),gimlev(:)    ! midpoint and interface mag levels
!
! All model times on the file (not just current history):
        integer,pointer :: mtimes(:,:) ! (3,nhist)
!
! Number of fields 2d,3d, geo,mag:
        integer ::
     |    nf3d_geo,          ! number of 3d geo fields (nlon,nlat,nlev)
     |    nf3d_mag,          ! number of 3d mag fields (mlon,mlat,mlev)
     |    nf2d_geo,          ! number of 2d geo fields (lon,lat)
     |    nf2d_mag           ! number of 2d mag fields (mlon,mlat)
!
! Field structures (see typedefs above):
        type(field_3d) :: f3d_geo(mxflds), f3d_mag(mxflds) 
        type(field_2d) :: f2d_geo(mxflds), f2d_mag(mxflds)
      end type history