mom_cap.F90

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!> This module contains a set of subroutines that are required by NUOPC.
 
module mom_cap_mod
 
use constants_mod,            only: constants_init
use diag_manager_mod,         only: diag_manager_init, diag_manager_end
use field_manager_mod,        only: field_manager_init, field_manager_end
use fms_mod,                  only: fms_init, fms_end, open_namelist_file, check_nml_error
use fms_mod,                  only: close_file, file_exist, uppercase
use fms_io_mod,               only: fms_io_exit
use mpp_domains_mod,          only: domain2d, mpp_get_compute_domain, mpp_get_compute_domains
use mpp_domains_mod,          only: mpp_get_ntile_count, mpp_get_pelist, mpp_get_global_domain
use mpp_domains_mod,          only: mpp_get_domain_npes
use mpp_io_mod,               only: mpp_open, mpp_rdonly, mpp_ascii, mpp_overwr, mpp_append, mpp_close, mpp_single
use mpp_mod,                  only: stdlog, stdout, mpp_root_pe, mpp_clock_id
use mpp_mod,                  only: mpp_clock_begin, mpp_clock_end, mpp_clock_sync
use mpp_mod,                  only: mpp_clock_detailed, clock_component, maxpes
use time_interp_external_mod, only: time_interp_external_init
use time_manager_mod,         only: set_calendar_type, time_type, increment_date
use time_manager_mod,         only: set_time, set_date, get_time, get_date, month_name
use time_manager_mod,         only: gregorian, julian, noleap, thirty_day_months, no_calendar
use time_manager_mod,         only: operator( <= ), operator( < ), operator( >= )
use time_manager_mod,         only: operator( + ),  operator( - ), operator( / )
use time_manager_mod,         only: operator( * ), operator( /= ), operator( > )
use time_manager_mod,         only: date_to_string
use time_manager_mod,         only: fms_get_calendar_type => get_calendar_type
use mom_domains,              only: mom_infra_init, num_pes, root_pe, pe_here
use mom_file_parser,          only: get_param, log_version, param_file_type, close_param_file
use mom_get_input,            only: get_mom_input, directories
use mom_domains,              only: pass_var
use mom_error_handler,        only: mom_error, fatal, is_root_pe
use mom_ocean_model_nuopc,    only: ice_ocean_boundary_type
use mom_grid,                 only: ocean_grid_type, get_global_grid_size
use mom_ocean_model_nuopc,    only: ocean_model_restart, ocean_public_type, ocean_state_type
use mom_ocean_model_nuopc,    only: ocean_model_init_sfc
use mom_ocean_model_nuopc,    only: ocean_model_init, update_ocean_model, ocean_model_end
use mom_ocean_model_nuopc,    only: get_ocean_grid, get_eps_omesh
use mom_cap_time,             only: alarminit
use mom_cap_methods,          only: mom_import, mom_export, mom_set_geomtype
#ifdef CESMCOUPLED
use shr_file_mod,             only: shr_file_setlogunit, shr_file_getlogunit
#endif
use time_utils_mod,           only: esmf2fms_time
 
use, intrinsic :: iso_fortran_env, only: output_unit
 
use esmf,  only: esmf_clockadvance, esmf_clockget, esmf_clockprint
use esmf,  only: esmf_clockgetalarm, esmf_clockgetnexttime, esmf_clockadvance
use esmf,  only: esmf_clockset, esmf_clock, esmf_geomtype_flag, esmf_logmsg_info
use esmf,  only: esmf_grid, esmf_gridcreate, esmf_gridaddcoord
use esmf,  only: esmf_gridgetcoord, esmf_gridadditem, esmf_gridgetitem
use esmf,  only: esmf_gridcomp, esmf_gridcompsetentrypoint, esmf_gridcompget
use esmf,  only: esmf_logfounderror, esmf_logwrite, esmf_logseterror
use esmf,  only: esmf_logerr_passthru, esmf_kind_r8, esmf_rc_val_wrong
use esmf,  only: esmf_geomtype_mesh, esmf_geomtype_grid, esmf_success
use esmf,  only: esmf_method_initialize, esmf_methodremove, esmf_state
use esmf,  only: esmf_logmsg_info, esmf_rc_arg_bad, esmf_vm, esmf_time
use esmf,  only: esmf_timeinterval, esmf_maxstr, esmf_vmgetcurrent
use esmf,  only: esmf_vmget, esmf_timeget, esmf_timeintervalget, esmf_meshget
use esmf,  only: esmf_methodexecute, esmf_mesh, esmf_delayout, esmf_distgrid
use esmf,  only: esmf_distgridconnection, esmf_stateitem_flag, esmf_kind_i4
use esmf,  only: esmf_kind_i8, esmf_failure, esmf_distgridcreate, esmf_meshcreate
use esmf,  only: esmf_fileformat_esmfmesh, esmf_delayoutcreate, esmf_distgridconnectionset
use esmf,  only: esmf_distgridget, esmf_staggerloc_corner, esmf_griditem_mask
use esmf,  only: esmf_typekind_i4, esmf_typekind_r8, esmf_staggerloc_center
use esmf,  only: esmf_griditem_area, esmf_field, esmf_alarm, esmf_vmlogmeminfo
use esmf,  only: esmf_alarmisringing, esmf_alarmringeroff, esmf_stateremove
use esmf,  only: esmf_fieldcreate, esmf_logmsg_error, esmf_logmsg_warning
use esmf,  only: esmf_coordsys_sph_deg, esmf_gridcreate, esmf_index_delocal
use esmf,  only: esmf_meshloc_element, esmf_rc_val_outofrange, esmf_stateget
use esmf,  only: esmf_timeprint, esmf_alarmset, esmf_fieldget, esmf_array
use esmf,  only: esmf_arraycreate
use esmf,  only: operator(==), operator(/=), operator(+), operator(-)
 
! TODO ESMF_GridCompGetInternalState does not have an explicit Fortran interface.
!! Model does not compile with "use ESMF,  only: ESMF_GridCompGetInternalState"
!! Is this okay?
 
use nuopc,       only: nuopc_compderive, nuopc_compsetentrypoint, nuopc_compspecialize
use nuopc,       only: nuopc_compfilterphasemap, nuopc_compattributeget, nuopc_compattributeadd
use nuopc,       only: nuopc_advertise, nuopc_setattribute, nuopc_isupdated, nuopc_write
use nuopc,       only: nuopc_isconnected, nuopc_realize, nuopc_compattributeset
use nuopc_model, only: nuopc_modelget
use nuopc_model, &
  model_routine_ss           => setservices, &
  model_label_advance        => label_advance, &
  model_label_datainitialize => label_datainitialize, &
  model_label_setrunclock    => label_setrunclock, &
  model_label_finalize       => label_finalize
 
implicit none; private
 
public setservices
 
!> Internal state type with pointers to three types defined by MOM.
type ocean_internalstate_type
  type(ocean_public_type),       pointer :: ocean_public_type_ptr
  type(ocean_state_type),        pointer :: ocean_state_type_ptr
  type(ice_ocean_boundary_type), pointer :: ice_ocean_boundary_type_ptr
end type
 
!>  Wrapper-derived type required to associate an internal state instance
!! with the ESMF/NUOPC component
type ocean_internalstate_wrapper
  type(ocean_internalstate_type), pointer :: ptr
end type
 
!> Contains field information
type fld_list_type
  character(len=64) :: stdname
  character(len=64) :: shortname
  character(len=64) :: transferoffer
end type fld_list_type
 
integer,parameter    :: fldsmax = 100
integer              :: fldstoocn_num = 0
type (fld_list_type) :: fldstoocn(fldsmax)
integer              :: fldsfrocn_num = 0
type (fld_list_type) :: fldsfrocn(fldsmax)
 
integer              :: debug = 0
integer              :: import_slice = 1
integer              :: export_slice = 1
character(len=256)   :: tmpstr
logical              :: write_diagnostics = .false.
logical              :: overwrite_timeslice = .false.
character(len=32)    :: runtype  !< run type
integer              :: logunit  !< stdout logging unit number
logical              :: profile_memory = .true.
logical              :: grid_attach_area = .false.
character(len=128)   :: scalar_field_name = ''
integer              :: scalar_field_count = 0
integer              :: scalar_field_idx_grid_nx = 0
integer              :: scalar_field_idx_grid_ny = 0
character(len=*),parameter :: u_file_u = &
     __file__
 
#ifdef CESMCOUPLED
logical :: cesm_coupled = .true.
type(esmf_geomtype_flag) :: geomtype = esmf_geomtype_mesh
#else
logical :: cesm_coupled = .false.
type(esmf_geomtype_flag) :: geomtype = esmf_geomtype_grid
#endif
 
contains
 
!> NUOPC SetService method is the only public entry point.
!! SetServices registers all of the user-provided subroutines
!! in the module with the NUOPC layer.
!!
!! @param gcomp an ESMF_GridComp object
!! @param rc return code
subroutine setservices(gcomp, rc)
 
  type(esmf_gridcomp)  :: gcomp !< an ESMF_GridComp object
  integer, intent(out) :: rc    !< return code
 
  ! local variables
  character(len=*),parameter  :: subname='(MOM_cap:SetServices)'
 
  rc = esmf_success
 
  ! the NUOPC model component will register the generic methods
  call nuopc_compderive(gcomp, model_routine_ss, rc=rc)
  if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
    line=__line__, &
    file=__file__)) &
    return  ! bail out
 
  ! switching to IPD versions
  call esmf_gridcompsetentrypoint(gcomp, esmf_method_initialize, &
    userroutine=initializep0, phase=0, rc=rc)
  if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
    line=__line__, &
    file=__file__)) &
    return  ! bail out
 
  ! set entry point for methods that require specific implementation
  call nuopc_compsetentrypoint(gcomp, esmf_method_initialize, &
    phaselabellist=(/"IPDv03p1"/), userroutine=initializeadvertise, rc=rc)
  if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
    line=__line__, &
    file=__file__)) &
    return  ! bail out
  call nuopc_compsetentrypoint(gcomp, esmf_method_initialize, &
    phaselabellist=(/"IPDv03p3"/), userroutine=initializerealize, rc=rc)
  if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
    line=__line__, &
    file=__file__)) &
    return  ! bail out
 
  !------------------
  ! attach specializing method(s)
  !------------------
 
  call nuopc_compspecialize(gcomp, speclabel=model_label_datainitialize, &
    specroutine=datainitialize, rc=rc)
  if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
    line=__line__, &
    file=__file__)) &
    return  ! bail out
 
  call nuopc_compspecialize(gcomp, speclabel=model_label_advance, &
    specroutine=modeladvance, rc=rc)
  if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
    line=__line__, &
    file=__file__)) &
    return  ! bail out
 
  call esmf_methodremove(gcomp, label=model_label_setrunclock, rc=rc)
  if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
    line=__line__, &
    file=__file__)) &
    return  ! bail out
  call nuopc_compspecialize(gcomp, speclabel=model_label_setrunclock, &
       specroutine=modelsetrunclock, rc=rc)
  if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
    line=__line__, &
    file=__file__)) &
    return  ! bail out
 
  call nuopc_compspecialize(gcomp, speclabel=model_label_finalize, &
    specroutine=ocean_model_finalize, rc=rc)
  if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
    line=__line__, &
    file=__file__)) &
    return  ! bail out
 
end subroutine setservices
 
!> First initialize subroutine called by NUOPC.  The purpose
!! is to set which version of the Initialize Phase Definition (IPD)
!! to use.
!!
!! For this MOM cap, we are using IPDv01.
!!
!! @param gcomp an ESMF_GridComp object
!! @param importState an ESMF_State object for import fields
!! @param exportState an ESMF_State object for export fields
!! @param clock an ESMF_Clock object
!! @param rc return code
subroutine initializep0(gcomp, importState, exportState, clock, rc)
  type(esmf_gridcomp)   :: gcomp                    !< ESMF_GridComp object
  type(esmf_state)      :: importState, exportState !< ESMF_State object for
                                                    !! import/export fields
  type(esmf_clock)      :: clock                    !< ESMF_Clock object
  integer, intent(out)  :: rc                       !< return code
 
  ! local variables
  logical                     :: isPresent, isSet
  integer                     :: iostat
  character(len=64)           :: value, logmsg
  character(len=*),parameter  :: subname='(MOM_cap:InitializeP0)'
 
  rc = esmf_success
 
  ! Switch to IPDv03 by filtering all other phaseMap entries
  call nuopc_compfilterphasemap(gcomp, esmf_method_initialize, &
       acceptstringlist=(/"IPDv03p"/), rc=rc)
  if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
       line=__line__, &
       file=__file__)) &
       return
 
  write_diagnostics = .false.
  call nuopc_compattributeget(gcomp, name="DumpFields", value=value, &
       ispresent=ispresent, isset=isset, rc=rc)
  if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
       line=__line__, &
       file=__file__)) &
       return
  if (ispresent .and. isset) write_diagnostics=(trim(value)=="true")
 
  write(logmsg,*) write_diagnostics
  call esmf_logwrite('MOM_cap:DumpFields = '//trim(logmsg), esmf_logmsg_info, rc=rc)
  if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
       line=__line__, &
       file=__file__)) &
       return
 
  overwrite_timeslice = .false.
  call nuopc_compattributeget(gcomp, name="OverwriteSlice", value=value, &
       ispresent=ispresent, isset=isset, rc=rc)
  if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
       line=__line__, &
       file=__file__)) &
       return
  if (ispresent .and. isset) overwrite_timeslice=(trim(value)=="true")
  write(logmsg,*) overwrite_timeslice
  call esmf_logwrite('MOM_cap:OverwriteSlice = '//trim(logmsg), esmf_logmsg_info, rc=rc)
  if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
       line=__line__, &
       file=__file__)) &
       return
 
  profile_memory = .false.
  call nuopc_compattributeget(gcomp, name="ProfileMemory", value=value, &
       ispresent=ispresent, isset=isset, rc=rc)
  if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
       line=__line__, &
       file=__file__)) &
       return
  if (ispresent .and. isset) profile_memory=(trim(value)=="true")
  write(logmsg,*) profile_memory
  call esmf_logwrite('MOM_cap:ProfileMemory = '//trim(logmsg), esmf_logmsg_info, rc=rc)
  if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
       line=__line__, &
       file=__file__)) &
       return
 
  grid_attach_area = .false.
  call nuopc_compattributeget(gcomp, name="GridAttachArea", value=value, &
       ispresent=ispresent, isset=isset, rc=rc)
  if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
       line=__line__, &
       file=__file__)) &
       return
  if (ispresent .and. isset) grid_attach_area=(trim(value)=="true")
  write(logmsg,*) grid_attach_area
  call esmf_logwrite('MOM_cap:GridAttachArea = '//trim(logmsg), esmf_logmsg_info, rc=rc)
  if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
       line=__line__, &
       file=__file__)) &
       return
 
  scalar_field_name = ""
  call nuopc_compattributeget(gcomp, name="ScalarFieldName", value=value, &
       ispresent=ispresent, isset=isset, rc=rc)
  if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
       line=__line__, &
       file=__file__)) &
       return
  if (ispresent .and. isset) then
     scalar_field_name = trim(value)
     call esmf_logwrite('MOM_cap:ScalarFieldName = '//trim(scalar_field_name), esmf_logmsg_info, rc=rc)
     if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
        line=__line__, &
        file=__file__)) &
        return
  endif
 
  scalar_field_count = 0
  call nuopc_compattributeget(gcomp, name="ScalarFieldCount", value=value, &
       ispresent=ispresent, isset=isset, rc=rc)
  if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
       line=__line__, &
       file=__file__)) &
       return
  if (ispresent .and. isset) then
     read(value, '(i)', iostat=iostat) scalar_field_count
     if (iostat /= 0) then
       call esmf_logseterror(esmf_rc_arg_bad, &
            msg=subname//": ScalarFieldCount not an integer: "//trim(value), &
            line=__line__, file=__file__, rctoreturn=rc)
       return
     endif
     write(logmsg,*) scalar_field_count
     call esmf_logwrite('MOM_cap:ScalarFieldCount = '//trim(logmsg), esmf_logmsg_info, rc=rc)
     if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
         line=__line__, &
         file=__file__)) &
         return
  endif
 
  scalar_field_idx_grid_nx = 0
  call nuopc_compattributeget(gcomp, name="ScalarFieldIdxGridNX", value=value, &
       ispresent=ispresent, isset=isset, rc=rc)
  if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
       line=__line__, &
       file=__file__)) &
       return
  if (ispresent .and. isset) then
     read(value, '(i)', iostat=iostat) scalar_field_idx_grid_nx
     if (iostat /= 0) then
        call esmf_logseterror(esmf_rc_arg_bad, &
             msg=subname//": ScalarFieldIdxGridNX not an integer: "//trim(value), &
             line=__line__, file=__file__, rctoreturn=rc)
        return
     endif
     write(logmsg,*) scalar_field_idx_grid_nx
     call esmf_logwrite('MOM_cap:ScalarFieldIdxGridNX = '//trim(logmsg), esmf_logmsg_info, rc=rc)
     if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
         line=__line__, &
         file=__file__)) &
         return
  endif
 
  scalar_field_idx_grid_ny = 0
  call nuopc_compattributeget(gcomp, name="ScalarFieldIdxGridNY", value=value, &
       ispresent=ispresent, isset=isset, rc=rc)
  if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
       line=__line__, &
       file=__file__)) &
       return
  if (ispresent .and. isset) then
     read(value, '(i)', iostat=iostat) scalar_field_idx_grid_ny
     if (iostat /= 0) then
        call esmf_logseterror(esmf_rc_arg_bad, &
             msg=subname//": ScalarFieldIdxGridNY not an integer: "//trim(value), &
             line=__line__, file=__file__, rctoreturn=rc)
        return
     endif
     write(logmsg,*) scalar_field_idx_grid_ny
     call esmf_logwrite('MOM_cap:ScalarFieldIdxGridNY = '//trim(logmsg), esmf_logmsg_info, rc=rc)
     if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
          line=__line__, &
          file=__file__)) &
          return
  endif
 
  call nuopc_compattributeadd(gcomp, &
       attrlist=(/'RestartFileToRead', 'RestartFileToWrite'/), rc=rc)
  if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
       line=__line__, &
       file=__file__)) &
       return
 
end subroutine
 
!> Called by NUOPC to advertise import and export fields.  "Advertise"
!! simply means that the standard names of all import and export
!! fields are supplied.  The NUOPC layer uses these to match fields
!! between components in the coupled system.
!!
!! @param gcomp an ESMF_GridComp object
!! @param importState an ESMF_State object for import fields
!! @param exportState an ESMF_State object for export fields
!! @param clock an ESMF_Clock object
!! @param rc return code
subroutine initializeadvertise(gcomp, importState, exportState, clock, rc)
  type(esmf_gridcomp)            :: gcomp                    !< ESMF_GridComp object
  type(esmf_state)               :: importState, exportState !< ESMF_State object for
                                                             !! import/export fields
  type(esmf_clock)               :: clock                    !< ESMF_Clock object
  integer, intent(out)           :: rc                       !< return code
 
  ! local variables
  type(esmf_vm)                          :: vm
  type(esmf_time)                        :: MyTime
  type(esmf_timeinterval)                :: TINT
  type (ocean_public_type),      pointer :: ocean_public => null()
  type (ocean_state_type),       pointer :: ocean_state => null()
  type(ice_ocean_boundary_type), pointer :: Ice_ocean_boundary => null()
  type(ocean_internalstate_wrapper)      :: ocean_internalstate
  type(ocean_grid_type),         pointer :: ocean_grid => null()
  type(time_type)                        :: Run_len      !< length of experiment
  type(time_type)                        :: time0        !< Start time of coupled model's calendar.
  type(time_type)                        :: time_start   !< The time at which to initialize the ocean model
  type(time_type)                        :: Time_restart
  type(time_type)                        :: DT
  integer                                :: DT_OCEAN
  integer                                :: isc,iec,jsc,jec
  integer                                :: year=0, month=0, day=0, hour=0, minute=0, second=0
  integer                                :: mpi_comm_mom
  integer                                :: i,n
  character(len=256)                     :: stdname, shortname
  character(len=32)                      :: starttype            ! model start type
  character(len=512)                     :: diro
  character(len=512)                     :: logfile
  character(ESMF_MAXSTR)                 :: cvalue
  logical                                :: isPresent, isPresentDiro, isPresentLogfile, isSet
  logical                                :: existflag
  integer                                :: userRc
  character(len=512)                     :: restartfile          ! Path/Name of restart file
  character(len=*), parameter            :: subname='(MOM_cap:InitializeAdvertise)'
  character(len=32)                      :: calendar
!--------------------------------
 
  rc = esmf_success
 
  call esmf_logwrite(subname//' enter', esmf_logmsg_info, rc=rc)
  if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
       line=__line__, &
       file=__file__)) &
       return
 
  allocate(ice_ocean_boundary)
  !allocate(ocean_state) ! ocean_model_init allocate this pointer
  allocate(ocean_public)
  allocate(ocean_internalstate%ptr)
  ocean_internalstate%ptr%ice_ocean_boundary_type_ptr => ice_ocean_boundary
  ocean_internalstate%ptr%ocean_public_type_ptr       => ocean_public
  ocean_internalstate%ptr%ocean_state_type_ptr        => ocean_state
 
  call esmf_vmgetcurrent(vm, rc=rc)
  if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
    line=__line__, &
    file=__file__)) &
    return  ! bail out
 
  call esmf_vmget(vm, mpicommunicator=mpi_comm_mom, rc=rc)
  if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
    line=__line__, &
    file=__file__)) &
    return  ! bail out
 
  call esmf_clockget(clock, currtime=mytime, timestep=tint,  rc=rc)
  if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
    line=__line__, &
    file=__file__)) &
    return  ! bail out
 
  call esmf_timeget (mytime, yy=year, mm=month, dd=day, h=hour, m=minute, s=second, rc=rc )
  if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
    line=__line__, &
    file=__file__)) &
    return  ! bail out
 
  CALL esmf_timeintervalget(tint, s=dt_ocean, rc=rc)
  if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
    line=__line__, &
    file=__file__)) &
    return  ! bail out
 
  call fms_init(mpi_comm_mom)
  call constants_init
  call field_manager_init
 
  ! determine the calendar
  if (cesm_coupled) then
     call nuopc_compattributeget(gcomp, name="calendar", value=cvalue, &
          ispresent=ispresent, isset=isset, rc=rc)
     if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
          line=__line__, &
          file=__file__)) &
          return  ! bail out
     if (ispresent .and. isset) then
        read(cvalue,*) calendar
        select case (trim(calendar))
           case ("NO_LEAP")
              call set_calendar_type (noleap)
           case ("GREGORIAN")
              call set_calendar_type (gregorian)
           case default
              call esmf_logseterror(esmf_rc_arg_bad, &
                 msg=subname//": Calendar not supported in MOM6: "//trim(calendar), &
                 line=__line__, file=__file__, rctoreturn=rc)
           end select
     else
        call set_calendar_type (noleap)
     endif
 
  else
     call set_calendar_type (julian)
  endif
 
  call diag_manager_init
 
  ! this ocean connector will be driven at set interval
  dt = set_time(dt_ocean, 0)
  ! get current time
  time_start = set_date(year,month,day,hour,minute,second)
 
  if (is_root_pe()) then
    write(logunit,*) subname//'current time: y,m,d-',year,month,day,'h,m,s=',hour,minute,second
  endif
 
  ! get start/reference time
  call esmf_clockget(clock, reftime=mytime, rc=rc)
  if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
    line=__line__, &
    file=__file__)) &
    return  ! bail out
 
  call esmf_timeget (mytime, yy=year, mm=month, dd=day, h=hour, m=minute, s=second, rc=rc )
  if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
    line=__line__, &
    file=__file__)) &
    return  ! bail out
 
  time0 = set_date(year,month,day,hour,minute,second)
 
  if (is_root_pe()) then
    write(logunit,*) subname//'start time: y,m,d-',year,month,day,'h,m,s=',hour,minute,second
  endif
 
  ! rsd need to figure out how to get this without share code
  !call shr_nuopc_get_component_instance(gcomp, inst_suffix, inst_index)
  !inst_name = "OCN"//trim(inst_suffix)
 
  ! reset shr logging to my log file
  if (is_root_pe()) then
     call nuopc_compattributeget(gcomp, name="diro", &
          ispresent=ispresentdiro, rc=rc)
     if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
         line=__line__, &
         file=__file__)) &
         return
     call nuopc_compattributeget(gcomp, name="logfile", &
          ispresent=ispresentlogfile, rc=rc)
     if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
         line=__line__, &
         file=__file__)) &
         return
     if (ispresentdiro .and. ispresentlogfile) then
          call nuopc_compattributeget(gcomp, name="diro", value=diro, rc=rc)
          if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
              line=__line__, &
              file=__file__)) &
              return
          call nuopc_compattributeget(gcomp, name="logfile", value=logfile, rc=rc)
          if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
              line=__line__, &
              file=__file__)) &
              return
        open(newunit=logunit,file=trim(diro)//"/"//trim(logfile))
     else
        logunit = output_unit
     endif
  else
     logunit = output_unit
  endif
 
  starttype = ""
  call nuopc_compattributeget(gcomp, name='start_type', value=cvalue, &
       ispresent=ispresent, isset=isset, rc=rc)
  if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
       line=__line__, &
       file=__file__)) &
       return
  if (ispresent .and. isset) then
     read(cvalue,*) starttype
  else
     call esmf_logwrite('MOM_cap:start_type unset - using input.nml for restart option', &
          esmf_logmsg_info, rc=rc)
     if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
         line=__line__, &
         file=__file__)) &
         return
  endif
 
  runtype = ""
  if (trim(starttype) == trim('startup')) then
     runtype = "initial"
  else if (trim(starttype) == trim('continue') ) then
     runtype = "continue"
  else if (trim(starttype) == trim('branch')) then
     runtype = "continue"
  else if (len_trim(starttype) > 0) then
     call esmf_logseterror(esmf_rc_arg_bad, &
          msg=subname//": unknown starttype - "//trim(starttype), &
          line=__line__, file=__file__, rctoreturn=rc)
     return
  endif
 
  if (len_trim(runtype) > 0) then
     call esmf_logwrite('MOM_cap:startup = '//trim(runtype), esmf_logmsg_info, rc=rc)
     if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
         line=__line__, &
         file=__file__)) &
         return
  endif
 
  restartfile = ""
  if (runtype == "initial") then
     ! startup (new run) - 'n' is needed below if we don't specify input_filename in input.nml
     restartfile = "n"
  else if (runtype == "continue") then ! hybrid or branch or continuos runs
 
     ! optionally call into system-specific implementation to get restart file name
     call esmf_methodexecute(gcomp, label="GetRestartFileToRead", &
          existflag=existflag, userrc=userrc, rc=rc)
     if (esmf_logfounderror(rctocheck=rc, msg="Error executing user method to get restart filename", &
         line=__line__, &
         file=__file__)) &
         return  ! bail out
     if (esmf_logfounderror(rctocheck=userrc, msg="Error in method to get restart filename", &
         line=__line__, &
         file=__file__)) &
         return  ! bail out
     if (existflag) then
        call esmf_logwrite('MOM_cap: called user GetRestartFileToRead', esmf_logmsg_info, rc=rc)
        if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
            line=__line__, &
            file=__file__)) &
            return
     endif
 
     call nuopc_compattributeget(gcomp, name='RestartFileToRead', &
          value=cvalue, ispresent=ispresent, isset=isset, rc=rc)
     if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
         line=__line__, &
         file=__file__)) &
         return
     if (ispresent .and. isset) then
        restartfile = trim(cvalue)
        call esmf_logwrite('MOM_cap: RestartFileToRead = '//trim(restartfile), esmf_logmsg_info, rc=rc)
        if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
            line=__line__, &
            file=__file__)) &
            return
     else
        call esmf_logwrite('MOM_cap: restart requested, no RestartFileToRead attribute provided-will use input.nml',&
             esmf_logmsg_warning, rc=rc)
        if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
            line=__line__, &
            file=__file__)) &
            return
     endif
 
  endif
 
  ocean_public%is_ocean_pe = .true.
  call ocean_model_init(ocean_public, ocean_state, time0, time_start, input_restart_file=trim(restartfile))
 
  call ocean_model_init_sfc(ocean_state, ocean_public)
 
  call mpp_get_compute_domain(ocean_public%domain, isc, iec, jsc, jec)
 
  allocate ( ice_ocean_boundary% u_flux (isc:iec,jsc:jec),          &
             ice_ocean_boundary% v_flux (isc:iec,jsc:jec),          &
             ice_ocean_boundary% t_flux (isc:iec,jsc:jec),          &
             ice_ocean_boundary% q_flux (isc:iec,jsc:jec),          &
             ice_ocean_boundary% salt_flux (isc:iec,jsc:jec),       &
             ice_ocean_boundary% lw_flux (isc:iec,jsc:jec),         &
             ice_ocean_boundary% sw_flux_vis_dir (isc:iec,jsc:jec), &
             ice_ocean_boundary% sw_flux_vis_dif (isc:iec,jsc:jec), &
             ice_ocean_boundary% sw_flux_nir_dir (isc:iec,jsc:jec), &
             ice_ocean_boundary% sw_flux_nir_dif (isc:iec,jsc:jec), &
             ice_ocean_boundary% lprec (isc:iec,jsc:jec),           &
             ice_ocean_boundary% fprec (isc:iec,jsc:jec),           &
             ice_ocean_boundary% seaice_melt_heat (isc:iec,jsc:jec),&
             ice_ocean_boundary% seaice_melt (isc:iec,jsc:jec),     &
             ice_ocean_boundary% mi (isc:iec,jsc:jec),              &
             ice_ocean_boundary% p (isc:iec,jsc:jec),               &
             ice_ocean_boundary% lrunoff_hflx (isc:iec,jsc:jec),    &
             ice_ocean_boundary% frunoff_hflx (isc:iec,jsc:jec),    &
             ice_ocean_boundary% lrunoff (isc:iec,jsc:jec),       &
             ice_ocean_boundary% frunoff (isc:iec,jsc:jec))
 
  ice_ocean_boundary%u_flux          = 0.0
  ice_ocean_boundary%v_flux          = 0.0
  ice_ocean_boundary%t_flux          = 0.0
  ice_ocean_boundary%q_flux          = 0.0
  ice_ocean_boundary%salt_flux       = 0.0
  ice_ocean_boundary%lw_flux         = 0.0
  ice_ocean_boundary%sw_flux_vis_dir = 0.0
  ice_ocean_boundary%sw_flux_vis_dif = 0.0
  ice_ocean_boundary%sw_flux_nir_dir = 0.0
  ice_ocean_boundary%sw_flux_nir_dif = 0.0
  ice_ocean_boundary%lprec           = 0.0
  ice_ocean_boundary%fprec           = 0.0
  ice_ocean_boundary%seaice_melt     = 0.0
  ice_ocean_boundary%seaice_melt_heat= 0.0
  ice_ocean_boundary%mi              = 0.0
  ice_ocean_boundary%p               = 0.0
  ice_ocean_boundary%lrunoff_hflx    = 0.0
  ice_ocean_boundary%frunoff_hflx    = 0.0
  ice_ocean_boundary%lrunoff         = 0.0
  ice_ocean_boundary%frunoff         = 0.0
 
  ocean_internalstate%ptr%ocean_state_type_ptr => ocean_state
  call esmf_gridcompsetinternalstate(gcomp, ocean_internalstate, rc)
  if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
    line=__line__, &
    file=__file__)) &
    return  ! bail out
 
  if (len_trim(scalar_field_name) > 0) then
   call fld_list_add(fldstoocn_num, fldstoocn, trim(scalar_field_name), "will_provide")
   call fld_list_add(fldsfrocn_num, fldsfrocn, trim(scalar_field_name), "will_provide")
  end if
 
  if (cesm_coupled) then
    !call fld_list_add(fldsToOcn_num, fldsToOcn, "Sw_lamult"                 , "will provide")
    !call fld_list_add(fldsToOcn_num, fldsToOcn, "Sw_ustokes"                , "will provide")
    !call fld_list_add(fldsToOcn_num, fldsToOcn, "Sw_vstokes"                , "will provide")
    !call fld_list_add(fldsToOcn_num, fldsToOcn, "Sw_hstokes"                , "will provide")
    !call fld_list_add(fldsToOcn_num, fldsToOcn, "Fioi_melth"                , "will provide")
    !call fld_list_add(fldsToOcn_num, fldsToOcn, "Fioi_meltw"                , "will provide")
    !call fld_list_add(fldsFrOcn_num, fldsFrOcn, "So_fswpen"                 , "will provide")
  else
    !call fld_list_add(fldsToOcn_num, fldsToOcn, "mass_of_overlying_sea_ice" , "will provide")
    !call fld_list_add(fldsFrOcn_num, fldsFrOcn, "sea_lev"                   , "will provide")
  endif
 
  !--------- import fields -------------
  call fld_list_add(fldstoocn_num, fldstoocn, "mean_salt_rate"             , "will provide") ! from ice
  call fld_list_add(fldstoocn_num, fldstoocn, "mean_zonal_moment_flx"      , "will provide")
  call fld_list_add(fldstoocn_num, fldstoocn, "mean_merid_moment_flx"      , "will provide")
  call fld_list_add(fldstoocn_num, fldstoocn, "mean_sensi_heat_flx"        , "will provide")
  call fld_list_add(fldstoocn_num, fldstoocn, "mean_evap_rate"             , "will provide")
  call fld_list_add(fldstoocn_num, fldstoocn, "mean_net_lw_flx"            , "will provide")
  call fld_list_add(fldstoocn_num, fldstoocn, "mean_net_sw_vis_dir_flx"    , "will provide")
  call fld_list_add(fldstoocn_num, fldstoocn, "mean_net_sw_vis_dif_flx"    , "will provide")
  call fld_list_add(fldstoocn_num, fldstoocn, "mean_net_sw_ir_dir_flx"     , "will provide")
  call fld_list_add(fldstoocn_num, fldstoocn, "mean_net_sw_ir_dif_flx"     , "will provide")
  call fld_list_add(fldstoocn_num, fldstoocn, "mean_prec_rate"             , "will provide")
  call fld_list_add(fldstoocn_num, fldstoocn, "mean_fprec_rate"            , "will provide")
  call fld_list_add(fldstoocn_num, fldstoocn, "inst_pres_height_surface"   , "will provide")
  call fld_list_add(fldstoocn_num, fldstoocn, "Foxx_rofl"                  , "will provide") !-> liquid runoff
  call fld_list_add(fldstoocn_num, fldstoocn, "Foxx_rofi"                  , "will provide") !-> ice runoff
  call fld_list_add(fldstoocn_num, fldstoocn, "mean_fresh_water_to_ocean_rate", "will provide")
  call fld_list_add(fldstoocn_num, fldstoocn, "net_heat_flx_to_ocn"        , "will provide")
  !These are not currently used and changing requires a nuopc dictionary change
  !call fld_list_add(fldsToOcn_num, fldsToOcn, "mean_runoff_heat_flx"        , "will provide")
  !call fld_list_add(fldsToOcn_num, fldsToOcn, "mean_calving_heat_flx"       , "will provide")
 
  !--------- export fields -------------
  call fld_list_add(fldsfrocn_num, fldsfrocn, "ocean_mask"                 , "will provide")
  call fld_list_add(fldsfrocn_num, fldsfrocn, "sea_surface_temperature"    , "will provide")
  call fld_list_add(fldsfrocn_num, fldsfrocn, "s_surf"                     , "will provide")
  call fld_list_add(fldsfrocn_num, fldsfrocn, "ocn_current_zonal"          , "will provide")
  call fld_list_add(fldsfrocn_num, fldsfrocn, "ocn_current_merid"          , "will provide")
  call fld_list_add(fldsfrocn_num, fldsfrocn, "sea_surface_slope_zonal"    , "will provide")
  call fld_list_add(fldsfrocn_num, fldsfrocn, "sea_surface_slope_merid"    , "will provide")
  call fld_list_add(fldsfrocn_num, fldsfrocn, "freezing_melting_potential" , "will provide")
  call fld_list_add(fldsfrocn_num, fldsfrocn, "So_bldepth"                 , "will provide")
 
  do n = 1,fldstoocn_num
    call nuopc_advertise(importstate, standardname=fldstoocn(n)%stdname, name=fldstoocn(n)%shortname, rc=rc)
    if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
      line=__line__, &
      file=__file__)) &
      return  ! bail out
  enddo
 
  do n = 1,fldsfrocn_num
    call nuopc_advertise(exportstate, standardname=fldsfrocn(n)%stdname, name=fldsfrocn(n)%shortname, rc=rc)
    if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
      line=__line__, &
      file=__file__)) &
      return  ! bail out
  enddo
 
end subroutine initializeadvertise
 
!> Called by NUOPC to realize import and export fields.  "Realizing" a field
!! means that its grid has been defined and an ESMF_Field object has been
!! created and put into the import or export State.
!!
!! @param gcomp an ESMF_GridComp object
!! @param importState an ESMF_State object for import fields
!! @param exportState an ESMF_State object for export fields
!! @param clock an ESMF_Clock object
!! @param rc return code
subroutine initializerealize(gcomp, importState, exportState, clock, rc)
  type(esmf_gridcomp)  :: gcomp                    !< ESMF_GridComp object
  type(esmf_state)     :: importState, exportState !< ESMF_State object for
                                                   !! import/export fields
  type(esmf_clock)     :: clock                    !< ESMF_Clock object
  integer, intent(out) :: rc                       !< return code
 
  ! Local Variables
  type(esmf_vm)                              :: vm
  type(esmf_grid)                            :: gridIn, gridOut
  type(esmf_mesh)                            :: Emesh, EmeshTemp
  type(esmf_delayout)                        :: delayout
  type(esmf_distgrid)                        :: Distgrid
  type(esmf_distgridconnection), allocatable :: connectionList(:)
  type(esmf_stateitem_flag)                  :: itemFlag
  type (ocean_public_type),      pointer     :: ocean_public   => null()
  type (ocean_state_type),       pointer     :: ocean_state => null()
  type(ice_ocean_boundary_type), pointer     :: Ice_ocean_boundary => null()
  type(ocean_grid_type)        , pointer     :: ocean_grid
  type(ocean_internalstate_wrapper)          :: ocean_internalstate
  integer                                    :: npet, ntiles
  integer                                    :: nxg, nyg, cnt
  integer                                    :: isc,iec,jsc,jec
  integer, allocatable                       :: xb(:),xe(:),yb(:),ye(:),pe(:)
  integer, allocatable                       :: deBlockList(:,:,:)
  integer, allocatable                       :: petMap(:)
  integer, allocatable                       :: deLabelList(:)
  integer, allocatable                       :: indexList(:)
  integer                                    :: ioff, joff
  integer                                    :: i, j, n, i1, j1, n1, jlast
  integer                                    :: lbnd1,ubnd1,lbnd2,ubnd2
  integer                                    :: lbnd3,ubnd3,lbnd4,ubnd4
  integer                                    :: nblocks_tot
  logical                                    :: found
  integer(ESMF_KIND_I4), pointer             :: dataPtr_mask(:,:)
  real(ESMF_KIND_R8), pointer                :: dataPtr_area(:,:)
  real(ESMF_KIND_R8), pointer                :: dataPtr_xcen(:,:)
  real(ESMF_KIND_R8), pointer                :: dataPtr_ycen(:,:)
  real(ESMF_KIND_R8), pointer                :: dataPtr_xcor(:,:)
  real(ESMF_KIND_R8), pointer                :: dataPtr_ycor(:,:)
  integer                                    :: mpicom
  integer                                    :: localPet
  integer                                    :: lsize
  integer                                    :: ig,jg, ni,nj,k
  integer, allocatable                       :: gindex(:) ! global index space
  character(len=128)                         :: fldname
  character(len=256)                         :: cvalue
  character(len=256)                         :: frmt    ! format specifier for several error msgs
  character(len=512)                         :: err_msg ! error messages
  character(len=*), parameter                :: subname='(MOM_cap:InitializeRealize)'
  integer                         :: spatialDim
  integer                         :: numOwnedElements
  type(esmf_array)                :: elemMaskArray
  real(ESMF_KIND_R8)    , pointer :: ownedElemCoords(:)
  real(ESMF_KIND_R8)    , pointer :: lat(:), latMesh(:)
  real(ESMF_KIND_R8)    , pointer :: lon(:), lonMesh(:)
  integer(ESMF_KIND_I4) , pointer :: mask(:), maskMesh(:)
  real(ESMF_KIND_R8)              :: diff_lon, diff_lat
  real                            :: eps_omesh
  !--------------------------------
 
  rc = esmf_success
 
  call shr_file_setlogunit (logunit)
 
  !----------------------------------------------------------------------------
  ! Get pointers to ocean internal state
  !----------------------------------------------------------------------------
 
  call esmf_gridcompgetinternalstate(gcomp, ocean_internalstate, rc)
  if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
    line=__line__, &
    file=__file__)) &
    return  ! bail out
 
  ice_ocean_boundary => ocean_internalstate%ptr%ice_ocean_boundary_type_ptr
  ocean_public       => ocean_internalstate%ptr%ocean_public_type_ptr
  ocean_state        => ocean_internalstate%ptr%ocean_state_type_ptr
 
  !----------------------------------------------------------------------------
  ! Get mpi information
  !----------------------------------------------------------------------------
 
  call esmf_vmgetcurrent(vm, rc=rc)
  if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
    line=__line__, &
    file=__file__)) &
    return  ! bail out
 
  call esmf_vmget(vm, petcount=npet, mpicommunicator=mpicom, localpet=localpet, rc=rc)
  if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
    line=__line__, &
    file=__file__)) &
    return  ! bail out
 
  !---------------------------------
  ! global mom grid size
  !---------------------------------
 
  call mpp_get_global_domain(ocean_public%domain, xsize=nxg, ysize=nyg)
  write(tmpstr,'(a,2i6)') subname//' nxg,nyg = ',nxg,nyg
  call esmf_logwrite(trim(tmpstr), esmf_logmsg_info, rc=rc)
  if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
       line=__line__, &
       file=__file__)) &
       return  ! bail out
 
  !---------------------------------
  ! number of tiles per PET, assumed to be 1, and number of pes (tiles) total
  !---------------------------------
 
  ntiles=mpp_get_ntile_count(ocean_public%domain) ! this is tiles on this pe
  if (ntiles /= 1) then
    rc = esmf_failure
    call esmf_logwrite(subname//' ntiles must be 1', esmf_logmsg_error, rc=rc)
    if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
        line=__line__, &
        file=__file__)) &
        return
  endif
  ntiles=mpp_get_domain_npes(ocean_public%domain)
  write(tmpstr,'(a,1i6)') subname//' ntiles = ',ntiles
  call esmf_logwrite(trim(tmpstr), esmf_logmsg_info, rc=rc)
  if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
       line=__line__, &
       file=__file__)) &
       return
 
  !---------------------------------
  ! get start and end indices of each tile and their PET
  !---------------------------------
 
  allocate(xb(ntiles),xe(ntiles),yb(ntiles),ye(ntiles),pe(ntiles))
  call mpp_get_compute_domains(ocean_public%domain, xbegin=xb, xend=xe, ybegin=yb, yend=ye)
  call mpp_get_pelist(ocean_public%domain, pe)
  if (debug > 0) then
     do n = 1,ntiles
        write(tmpstr,'(a,6i6)') subname//' tiles ',n,pe(n),xb(n),xe(n),yb(n),ye(n)
        call esmf_logwrite(trim(tmpstr), esmf_logmsg_info, rc=rc)
        if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
            line=__line__, &
            file=__file__)) &
            return
     enddo
  endif
 
  !---------------------------------
  ! Create either a grid or a mesh
  !---------------------------------
 
   !Get the ocean grid and sizes of global and computational domains
   call get_ocean_grid(ocean_state, ocean_grid)
 
  if (geomtype == esmf_geomtype_mesh) then
 
     !---------------------------------
     ! Create a MOM6 mesh
     !---------------------------------
 
     call get_global_grid_size(ocean_grid, ni, nj)
     lsize = ( ocean_grid%iec - ocean_grid%isc + 1 ) * ( ocean_grid%jec - ocean_grid%jsc + 1 )
 
     ! Create the global index space for the computational domain
     allocate(gindex(lsize))
     k = 0
     do j = ocean_grid%jsc, ocean_grid%jec
        jg = j + ocean_grid%jdg_offset
        do i = ocean_grid%isc, ocean_grid%iec
           ig = i + ocean_grid%idg_offset
           k = k + 1 ! Increment position within gindex
           gindex(k) = ni * (jg - 1) + ig
        enddo
     enddo
 
     distgrid = esmf_distgridcreate(arbseqindexlist=gindex, rc=rc)
     if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
         line=__line__, &
         file=__file__)) &
         return
 
     ! read in the mesh
     call nuopc_compattributeget(gcomp, name='mesh_ocn', value=cvalue, rc=rc)
     if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
         line=__line__, &
         file=__file__)) &
         return
 
     emeshtemp = esmf_meshcreate(filename=trim(cvalue), fileformat=esmf_fileformat_esmfmesh, rc=rc)
     if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
         line=__line__, &
         file=__file__)) &
         return
 
     if (localpet == 0) then
        write(logunit,*)'mesh file for mom6 domain is ',trim(cvalue)
     endif
 
     ! recreate the mesh using the above distGrid
     emesh = esmf_meshcreate(emeshtemp, elementdistgrid=distgrid, rc=rc)
     if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
         line=__line__, &
         file=__file__)) &
         return
 
     ! Check for consistency of lat, lon and mask between mesh and mom6 grid
     call esmf_meshget(emesh, spatialdim=spatialdim, numownedelements=numownedelements, rc=rc)
     if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
          line=__line__, &
          file=__file__)) &
          return
 
     allocate(ownedelemcoords(spatialdim*numownedelements))
     allocate(lonmesh(numownedelements), lon(numownedelements))
     allocate(latmesh(numownedelements), lat(numownedelements))
     allocate(maskmesh(numownedelements), mask(numownedelements))
 
     call esmf_meshget(emesh, ownedelemcoords=ownedelemcoords, rc=rc)
     if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
          line=__line__, &
          file=__file__)) &
          return
     do n = 1,numownedelements
        lonmesh(n) = ownedelemcoords(2*n-1)
        latmesh(n) = ownedelemcoords(2*n)
     end do
 
     elemmaskarray = esmf_arraycreate(distgrid, maskmesh, rc=rc)
     if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
          line=__line__, &
          file=__file__)) &
          return
     call esmf_meshget(emesh, elemmaskarray=elemmaskarray, rc=rc)
     if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
          line=__line__, &
          file=__file__)) &
          return
 
     call mpp_get_compute_domain(ocean_public%domain, isc, iec, jsc, jec)
     n = 0
     do j = jsc, jec
       jg = j + ocean_grid%jsc - jsc
       do i = isc, iec
         ig = i + ocean_grid%isc - isc
         n = n+1
         mask(n) = ocean_grid%mask2dT(ig,jg)
         lon(n)  = ocean_grid%geolonT(ig,jg)
         lat(n)  = ocean_grid%geolatT(ig,jg)
       end do
     end do
 
     eps_omesh = get_eps_omesh(ocean_state)
     do n = 1,numownedelements
       diff_lon = abs(mod(lonmesh(n) - lon(n),360.0))
       if (diff_lon > eps_omesh) then
         frmt = "('ERROR: Difference between ESMF Mesh and MOM6 domain coords is "//&
                "greater than parameter EPS_OMESH. n, lonMesh(n), lon(n), diff_lon, "//&
                "EPS_OMESH= ',i8,2(f21.13,3x),2(d21.5))"
         write(err_msg, frmt)n,lonmesh(n),lon(n), diff_lon, eps_omesh
         call mom_error(fatal, err_msg)
       end if
       diff_lat = abs(latmesh(n) - lat(n))
       if (diff_lat > eps_omesh) then
         frmt = "('ERROR: Difference between ESMF Mesh and MOM6 domain coords is"//&
                "greater than parameter EPS_OMESH. n, latMesh(n), lat(n), diff_lat, "//&
                "EPS_OMESH= ',i8,2(f21.13,3x),2(d21.5))"
         write(err_msg, frmt)n,latmesh(n),lat(n), diff_lat, eps_omesh
         call mom_error(fatal, err_msg)
        end if
        if (abs(maskmesh(n) - mask(n)) > 0) then
          frmt = "('ERROR: ESMF mesh and MOM6 domain masks are inconsistent! - "//&
                 "MOM n, maskMesh(n), mask(n) = ',3(i8,2x))"
          write(err_msg, frmt)n,maskmesh(n),mask(n)
          call mom_error(fatal, err_msg)
        end if
     end do
 
     deallocate(ownedelemcoords)
     deallocate(lonmesh , lon )
     deallocate(latmesh , lat )
     deallocate(maskmesh, mask)
     ! realize the import and export fields using the mesh
     call mom_realizefields(importstate, fldstoocn_num, fldstoocn, "Ocn import", mesh=emesh, rc=rc)
     if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
         line=__line__, &
         file=__file__)) &
         return
 
     call mom_realizefields(exportstate, fldsfrocn_num, fldsfrocn, "Ocn export", mesh=emesh, rc=rc)
     if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
         line=__line__, &
         file=__file__)) &
         return
 
  else if (geomtype == esmf_geomtype_grid) then
 
     !---------------------------------
     ! create a MOM6 grid
     !---------------------------------
 
     ! generate delayout and dist_grid
 
     allocate(deblocklist(2,2,ntiles))
     allocate(petmap(ntiles))
     allocate(delabellist(ntiles))
 
     do n = 1, ntiles
       delabellist(n) = n
       deblocklist(1,1,n) = xb(n)
       deblocklist(1,2,n) = xe(n)
       deblocklist(2,1,n) = yb(n)
       deblocklist(2,2,n) = ye(n)
       petmap(n) = pe(n)
       ! write(tmpstr,'(a,3i8)') subname//' iglo = ',n,deBlockList(1,1,n),deBlockList(1,2,n)
       ! call ESMF_LogWrite(trim(tmpstr), ESMF_LOGMSG_INFO, rc=rc)
       ! write(tmpstr,'(a,3i8)') subname//' jglo = ',n,deBlockList(2,1,n),deBlockList(2,2,n)
       ! call ESMF_LogWrite(trim(tmpstr), ESMF_LOGMSG_INFO, rc=rc)
       ! write(tmpstr,'(a,2i8)') subname//' pe  = ',n,petMap(n)
       ! call ESMF_LogWrite(trim(tmpstr), ESMF_LOGMSG_INFO, rc=rc)
       !--- assume a tile with starting index of 1 has an equivalent wraparound tile on the other side
     enddo
 
     delayout = esmf_delayoutcreate(petmap, rc=rc)
     if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
         line=__line__, &
         file=__file__)) &
         return  ! bail out
 
     ! rsd this assumes tripole grid, but sometimes in CESM a bipole
     ! grid is used -- need to introduce conditional logic here
 
     allocate(connectionlist(2))
 
     ! bipolar boundary condition at top row: nyg
     call esmf_distgridconnectionset(connectionlist(1), tileindexa=1, &
          tileindexb=1, positionvector=(/nxg+1, 2*nyg+1/), &
          orientationvector=(/-1, -2/), rc=rc)
     if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
         line=__line__, &
         file=__file__)) &
         return  ! bail out
 
     ! periodic boundary condition along first dimension
     call esmf_distgridconnectionset(connectionlist(2), tileindexa=1, &
          tileindexb=1, positionvector=(/nxg, 0/), rc=rc)
     if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
         line=__line__, &
         file=__file__)) &
         return
 
     distgrid = esmf_distgridcreate(minindex=(/1,1/), maxindex=(/nxg,nyg/), &
          !        indexflag = ESMF_INDEX_DELOCAL, &
          deblocklist=deblocklist, &
          !        deLabelList=deLabelList, &
          delayout=delayout, &
          connectionlist=connectionlist, &
          rc=rc)
     if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
         line=__line__, &
         file=__file__)) &
         return
 
     deallocate(xb,xe,yb,ye,pe)
     deallocate(connectionlist)
     deallocate(delabellist)
     deallocate(deblocklist)
     deallocate(petmap)
 
     call esmf_distgridget(distgrid=distgrid, localde=0, elementcount=cnt, rc=rc)
     if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
         line=__line__, &
         file=__file__)) &
         return
 
     allocate(indexlist(cnt))
     write(tmpstr,'(a,i8)') subname//' distgrid cnt= ',cnt
     call esmf_logwrite(trim(tmpstr), esmf_logmsg_info, rc=rc)
     if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
         line=__line__, &
         file=__file__)) &
         return
 
     call esmf_distgridget(distgrid=distgrid, localde=0, seqindexlist=indexlist, rc=rc)
     if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
         line=__line__, &
         file=__file__)) &
         return
 
     write(tmpstr,'(a,4i8)') subname//' distgrid list= ',&
          indexlist(1),indexlist(cnt),minval(indexlist), maxval(indexlist)
     call esmf_logwrite(trim(tmpstr), esmf_logmsg_info, rc=rc)
     if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
         line=__line__, &
         file=__file__)) &
         return
 
     deallocate(indexlist)
 
     ! create grid
 
     gridin = esmf_gridcreate(distgrid=distgrid, &
          gridedgelwidth=(/0,0/), gridedgeuwidth=(/0,1/), &
          coordsys = esmf_coordsys_sph_deg, &
          rc = rc)
     if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
         line=__line__, &
         file=__file__)) &
         return
 
 
     call esmf_gridaddcoord(gridin, staggerloc=esmf_staggerloc_center, rc=rc)
     if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
         line=__line__, &
         file=__file__)) &
         return
 
     call esmf_gridaddcoord(gridin, staggerloc=esmf_staggerloc_corner, rc=rc)
     if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
         line=__line__, &
         file=__file__)) &
         return
 
     call esmf_gridadditem(gridin, itemflag=esmf_griditem_mask, itemtypekind=esmf_typekind_i4, &
          staggerloc=esmf_staggerloc_center, rc=rc)
     if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
         line=__line__, &
         file=__file__)) &
         return
 
     ! Attach area to the Grid optionally. By default the cell areas are computed.
     if(grid_attach_area) then
        call esmf_gridadditem(gridin, itemflag=esmf_griditem_area, itemtypekind=esmf_typekind_r8, &
             staggerloc=esmf_staggerloc_center, rc=rc)
        if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
           line=__line__, &
           file=__file__)) &
           return
 
     endif
 
     call esmf_gridgetcoord(gridin, coorddim=1, &
          staggerloc=esmf_staggerloc_center, &
          farrayptr=dataptr_xcen, rc=rc)
     if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
         line=__line__, &
         file=__file__)) &
         return
 
     call esmf_gridgetcoord(gridin, coorddim=2, &
          staggerloc=esmf_staggerloc_center, &
          farrayptr=dataptr_ycen, rc=rc)
     if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
         line=__line__, &
         file=__file__)) &
         return
 
 
     call esmf_gridgetcoord(gridin, coorddim=1, &
          staggerloc=esmf_staggerloc_corner, &
          farrayptr=dataptr_xcor, rc=rc)
     if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
         line=__line__, &
         file=__file__)) &
         return
 
     call esmf_gridgetcoord(gridin, coorddim=2, &
          staggerloc=esmf_staggerloc_corner, &
          farrayptr=dataptr_ycor, rc=rc)
     if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
         line=__line__, &
         file=__file__)) &
         return
 
     call esmf_gridgetitem(gridin, itemflag=esmf_griditem_mask, &
          staggerloc=esmf_staggerloc_center, &
          farrayptr=dataptr_mask, rc=rc)
     if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
         line=__line__, &
         file=__file__)) &
         return
 
     if(grid_attach_area) then
       call esmf_gridgetitem(gridin, itemflag=esmf_griditem_area, &
             staggerloc=esmf_staggerloc_center, &
             farrayptr=dataptr_area, rc=rc)
       if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
         line=__line__, &
         file=__file__)) &
         return
     endif
 
     ! load up area, mask, center and corner values
     ! area, mask, and centers should be same size in mom and esmf grid
     ! corner points may not be, need to offset corner points by 1 in i and j
     ! retrieve these values directly from ocean_grid, which contains halo
     ! values for j=0 and wrap-around in i. on tripole seam, decomposition
     ! domains are 1 larger in j; to load corner values need to loop one extra row
 
     call mpp_get_compute_domain(ocean_public%domain, isc, iec, jsc, jec)
 
     lbnd1 = lbound(dataptr_mask,1)
     ubnd1 = ubound(dataptr_mask,1)
     lbnd2 = lbound(dataptr_mask,2)
     ubnd2 = ubound(dataptr_mask,2)
 
     lbnd3 = lbound(dataptr_xcor,1)
     ubnd3 = ubound(dataptr_xcor,1)
     lbnd4 = lbound(dataptr_xcor,2)
     ubnd4 = ubound(dataptr_xcor,2)
 
     write(tmpstr,*) subname//' iscjsc = ',isc,iec,jsc,jec
     call esmf_logwrite(trim(tmpstr), esmf_logmsg_info, rc=rc)
 
     write(tmpstr,*) subname//' lbub12 = ',lbnd1,ubnd1,lbnd2,ubnd2
     call esmf_logwrite(trim(tmpstr), esmf_logmsg_info, rc=rc)
 
     write(tmpstr,*) subname//' lbub34 = ',lbnd3,ubnd3,lbnd4,ubnd4
     call esmf_logwrite(trim(tmpstr), esmf_logmsg_info, rc=rc)
 
     if (iec-isc /= ubnd1-lbnd1 .or. jec-jsc /= ubnd2-lbnd2) then
        call esmf_logseterror(esmf_rc_arg_bad, &
             msg=subname//": fld and grid do not have the same size.", &
             line=__line__, file=__file__, rctoreturn=rc)
        return
     endif
 
     do j = jsc, jec
       j1 = j + lbnd2 - jsc
       jg = j + ocean_grid%jsc - jsc
       do i = isc, iec
         i1 = i + lbnd1 - isc
         ig = i + ocean_grid%isc - isc
         dataptr_mask(i1,j1)  = ocean_grid%mask2dT(ig,jg)
         dataptr_xcen(i1,j1)  = ocean_grid%geolonT(ig,jg)
         dataptr_ycen(i1,j1)  = ocean_grid%geolatT(ig,jg)
         if(grid_attach_area) then
           dataptr_area(i1,j1) = ocean_grid%US%L_to_m**2 * ocean_grid%areaT(ig,jg)
         endif
       enddo
     enddo
 
     jlast = jec
     if(jec == nyg)jlast = jec+1
 
     do j = jsc, jlast
       j1 = j + lbnd4 - jsc
       jg = j + ocean_grid%jsc - jsc - 1
       do i = isc, iec
         i1 = i + lbnd3 - isc
         ig = i + ocean_grid%isc - isc - 1
         dataptr_xcor(i1,j1)  = ocean_grid%geolonBu(ig,jg)
         dataptr_ycor(i1,j1)  = ocean_grid%geolatBu(ig,jg)
       enddo
     enddo
 
     write(tmpstr,*) subname//' mask = ',minval(dataptr_mask),maxval(dataptr_mask)
     call esmf_logwrite(trim(tmpstr), esmf_logmsg_info, rc=rc)
 
     if(grid_attach_area) then
        write(tmpstr,*) subname//' area = ',minval(dataptr_area),maxval(dataptr_area)
        call esmf_logwrite(trim(tmpstr), esmf_logmsg_info, rc=rc)
     endif
 
     write(tmpstr,*) subname//' xcen = ',minval(dataptr_xcen),maxval(dataptr_xcen)
     call esmf_logwrite(trim(tmpstr), esmf_logmsg_info, rc=rc)
 
     write(tmpstr,*) subname//' ycen = ',minval(dataptr_ycen),maxval(dataptr_ycen)
     call esmf_logwrite(trim(tmpstr), esmf_logmsg_info, rc=rc)
 
     write(tmpstr,*) subname//' xcor = ',minval(dataptr_xcor),maxval(dataptr_xcor)
     call esmf_logwrite(trim(tmpstr), esmf_logmsg_info, rc=rc)
 
     write(tmpstr,*) subname//' ycor = ',minval(dataptr_ycor),maxval(dataptr_ycor)
     call esmf_logwrite(trim(tmpstr), esmf_logmsg_info, rc=rc)
 
     gridout = gridin ! for now out same as in
 
     call mom_realizefields(importstate, fldstoocn_num, fldstoocn, "Ocn import", grid=gridin, rc=rc)
     if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
         line=__line__, &
         file=__file__)) &
         return
 
     call mom_realizefields(exportstate, fldsfrocn_num, fldsfrocn, "Ocn export", grid=gridout, rc=rc)
     if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
         line=__line__, &
         file=__file__)) &
         return
 
  endif
 
  !---------------------------------
  ! set scalar data in export state
  !---------------------------------
 
  if (len_trim(scalar_field_name) > 0) then
     call state_setscalar(dble(nxg),scalar_field_idx_grid_nx, exportstate, localpet, &
         scalar_field_name, scalar_field_count, rc)
     if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
         line=__line__, &
         file=__file__)) &
         return
 
     call state_setscalar(dble(nyg),scalar_field_idx_grid_ny, exportstate, localpet, &
          scalar_field_name, scalar_field_count, rc)
     if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
         line=__line__, &
         file=__file__)) &
         return
 
  endif
 
  !---------------------------------
  ! Set module variable geomtype in MOM_cap_methods
  !---------------------------------
  call mom_set_geomtype(geomtype)
 
  !---------------------------------
  ! write out diagnostics
  !---------------------------------
 
  !call NUOPC_Write(exportState, fileNamePrefix='post_realize_field_ocn_export_', &
  !     timeslice=1, relaxedFlag=.true., rc=rc)
  !if (ESMF_LogFoundError(rcToCheck=rc, msg=ESMF_LOGERR_PASSTHRU, &
  !     line=__LINE__, &
  !     file=__FILE__)) &
  !     return  ! bail out
 
end subroutine initializerealize
 
!> TODO
!!
!! @param gcomp an ESMF_GridComp object
!! @param rc return code
subroutine datainitialize(gcomp, rc)
  type(esmf_gridcomp)  :: gcomp !< ESMF_GridComp object
  integer, intent(out) :: rc    !< return code
 
  ! local variables
  type(esmf_clock)                       :: clock
  type(esmf_state)                       :: importState, exportState
  type (ocean_public_type),      pointer :: ocean_public       => null()
  type (ocean_state_type),       pointer :: ocean_state        => null()
  type(ice_ocean_boundary_type), pointer :: Ice_ocean_boundary => null()
  type(ocean_internalstate_wrapper)      :: ocean_internalstate
  type(ocean_grid_type), pointer         :: ocean_grid
  character(240)                         :: msgString
  integer                                :: fieldCount, n
  type(esmf_field)                       :: field
  character(len=64),allocatable          :: fieldNameList(:)
  character(len=*),parameter  :: subname='(MOM_cap:DataInitialize)'
  !--------------------------------
 
  ! query the Component for its clock, importState and exportState
  call esmf_gridcompget(gcomp, clock=clock, importstate=importstate, exportstate=exportstate, rc=rc)
  if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
    line=__line__, &
    file=__file__)) &
    return  ! bail out
 
  call esmf_gridcompgetinternalstate(gcomp, ocean_internalstate, rc)
  if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
    line=__line__, &
    file=__file__)) &
    return  ! bail out
 
  ice_ocean_boundary => ocean_internalstate%ptr%ice_ocean_boundary_type_ptr
  ocean_public       => ocean_internalstate%ptr%ocean_public_type_ptr
  ocean_state        => ocean_internalstate%ptr%ocean_state_type_ptr
  call get_ocean_grid(ocean_state, ocean_grid)
 
  call mom_export(ocean_public, ocean_grid, ocean_state, exportstate, clock, rc=rc)
  if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
    line=__line__, &
    file=__file__)) &
    return  ! bail out
 
  call esmf_stateget(exportstate, itemcount=fieldcount, rc=rc)
  if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
    line=__line__, &
    file=__file__)) &
    return  ! bail out
 
  allocate(fieldnamelist(fieldcount))
  call esmf_stateget(exportstate, itemnamelist=fieldnamelist, rc=rc)
  if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
    line=__line__, &
    file=__file__)) &
    return  ! bail out
 
  do n=1, fieldcount
    call esmf_stateget(exportstate, itemname=fieldnamelist(n), field=field, rc=rc)
    if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
      line=__line__, &
      file=__file__)) &
      return  ! bail out
 
    call nuopc_setattribute(field, name="Updated", value="true", rc=rc)
    if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
      line=__line__, &
      file=__file__)) &
      return  ! bail out
  enddo
  deallocate(fieldnamelist)
 
  ! check whether all Fields in the exportState are "Updated"
  if (nuopc_isupdated(exportstate)) then
    call nuopc_compattributeset(gcomp, name="InitializeDataComplete", value="true", rc=rc)
 
    call esmf_logwrite("MOM6 - Initialize-Data-Dependency SATISFIED!!!", esmf_logmsg_info, rc=rc)
    if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
      line=__line__, &
      file=__file__)) &
      return  ! bail out
  endif
 
  if(write_diagnostics) then
    call nuopc_write(exportstate, filenameprefix='field_init_ocn_export_', &
      overwrite=overwrite_timeslice,timeslice=import_slice, relaxedflag=.true., rc=rc)
    if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
      line=__line__, &
      file=__file__)) &
      return  ! bail out
  endif
 
end subroutine datainitialize
 
!> Called by NUOPC to advance the model a single timestep.
!!
!! @param gcomp an ESMF_GridComp object
!! @param rc return code
subroutine modeladvance(gcomp, rc)
  type(esmf_gridcomp)                    :: gcomp !< ESMF_GridComp object
  integer, intent(out)                   :: rc    !< return code
 
  ! local variables
  integer                                :: userRc
  logical                                :: existflag, isPresent, isSet
  logical                                :: do_advance = .true.
  type(esmf_clock)                       :: clock!< ESMF Clock class definition
  type(esmf_alarm)                       :: alarm
  type(esmf_state)                       :: importState, exportState
  type(esmf_time)                        :: currTime
  type(esmf_timeinterval)                :: timeStep
  type(esmf_time)                        :: startTime
  type(esmf_timeinterval)                :: time_elapsed
  integer(ESMF_KIND_I8)                  :: n_interval, time_elapsed_sec
  character(len=64)                      :: timestamp
  type (ocean_public_type),      pointer :: ocean_public       => null()
  type (ocean_state_type),       pointer :: ocean_state        => null()
  type(ice_ocean_boundary_type), pointer :: Ice_ocean_boundary => null()
  type(ocean_internalstate_wrapper)      :: ocean_internalstate
  type(ocean_grid_type)        , pointer :: ocean_grid
  type(time_type)                        :: Time
  type(time_type)                        :: Time_step_coupled
  type(time_type)                        :: Time_restart_current
  integer                                :: dth, dtm, dts
  integer                                :: nc
  type(esmf_time)                        :: MyTime
  integer                                :: seconds, day, year, month, hour, minute
  character(ESMF_MAXSTR)                 :: restartname, cvalue
  character(240)                         :: msgString
  character(len=*),parameter             :: subname='(MOM_cap:ModelAdvance)'
 
  rc = esmf_success
  if(profile_memory) call esmf_vmlogmeminfo("Entering MOM Model_ADVANCE: ")
 
  call shr_file_setlogunit (logunit)
 
  ! query the Component for its clock, importState and exportState
  call esmf_gridcompget(gcomp, clock=clock, importstate=importstate, &
    exportstate=exportstate, rc=rc)
  if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
    line=__line__, &
    file=__file__)) &
    return  ! bail out
 
  ! HERE THE MODEL ADVANCES: currTime -> currTime + timeStep
 
  call esmf_clockprint(clock, options="currTime", &
    prestring="------>Advancing OCN from: ", unit=msgstring, rc=rc)
  if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
    line=__line__, &
    file=__file__)) &
    return  ! bail out
  call esmf_logwrite(subname//trim(msgstring), esmf_logmsg_info, rc=rc)
  if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
    line=__line__, &
    file=__file__)) &
    return  ! bail out
 
  call esmf_clockget(clock, starttime=starttime, currtime=currtime, &
    timestep=timestep, rc=rc)
  if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
    line=__line__, &
    file=__file__)) &
    return  ! bail out
 
  call esmf_timeprint(currtime + timestep, &
    prestring="--------------------------------> to: ", unit=msgstring, rc=rc)
  if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
    line=__line__, &
    file=__file__)) &
    return  ! bail out
  call esmf_logwrite(trim(msgstring), esmf_logmsg_info, rc=rc)
  if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
    line=__line__, &
    file=__file__)) &
    return  ! bail out
 
  time_step_coupled = esmf2fms_time(timestep)
  time = esmf2fms_time(currtime)
 
  !---------------
  ! Apply ocean lag for startup runs:
  !---------------
 
  if (cesm_coupled) then
    if (trim(runtype) == "initial") then
 
      ! Do not call MOM6 timestepping routine if the first cpl tstep of a startup run
      if (currtime == starttime) then
        call esmf_logwrite("MOM6 - Skipping the first coupling timestep", esmf_logmsg_info, rc=rc)
        if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
          line=__line__, &
          file=__file__)) &
          return  ! bail out
        do_advance = .false.
      else
        do_advance = .true.
      endif
 
      if (do_advance) then
         ! If the second cpl tstep of a startup run, step back a cpl tstep and advance for two cpl tsteps
         if (currtime == starttime + timestep) then
            call esmf_logwrite("MOM6 - Stepping back one coupling timestep", esmf_logmsg_info, rc=rc)
            if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
                 line=__line__, &
                 file=__file__)) &
                 return  ! bail out
            time = esmf2fms_time(currtime-timestep) ! i.e., startTime
 
            call esmf_logwrite("MOM6 - doubling the coupling timestep", esmf_logmsg_info, rc=rc)
            if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
                 line=__line__, &
                 file=__file__)) &
                 return  ! bail out
            time_step_coupled = 2 * esmf2fms_time(timestep)
         endif
      end if
 
    endif
  endif
 
  if (do_advance) then
 
     call esmf_gridcompgetinternalstate(gcomp, ocean_internalstate, rc)
     if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
          line=__line__, &
          file=__file__)) &
          return  ! bail out
 
     ice_ocean_boundary => ocean_internalstate%ptr%ice_ocean_boundary_type_ptr
     ocean_public       => ocean_internalstate%ptr%ocean_public_type_ptr
     ocean_state        => ocean_internalstate%ptr%ocean_state_type_ptr
 
     !---------------
     ! Write diagnostics for import
     !---------------
 
     if (write_diagnostics) then
        call nuopc_write(importstate, filenameprefix='field_ocn_import_', &
             overwrite=overwrite_timeslice,timeslice=import_slice, relaxedflag=.true., rc=rc)
        if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
             line=__line__, &
             file=__file__)) &
             return  ! bail out
        import_slice = import_slice + 1
     endif
 
     !---------------
     ! Get ocean grid
     !---------------
 
     call get_ocean_grid(ocean_state, ocean_grid)
 
     !---------------
     ! Import data
     !---------------
 
     call mom_import(ocean_public, ocean_grid, importstate, ice_ocean_boundary, rc=rc)
     if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
          line=__line__, &
          file=__file__)) &
          return  ! bail out
 
     !---------------
     ! Update MOM6
     !---------------
 
     if(profile_memory) call esmf_vmlogmeminfo("Entering MOM update_ocean_model: ")
     call update_ocean_model(ice_ocean_boundary, ocean_state, ocean_public, time, time_step_coupled)
     if(profile_memory) call esmf_vmlogmeminfo("Leaving MOM update_ocean_model: ")
 
     !---------------
     ! Export Data
     !---------------
 
     call mom_export(ocean_public, ocean_grid, ocean_state, exportstate, clock, rc=rc)
     if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
          line=__line__, &
          file=__file__)) &
          return  ! bail out
 
  endif
 
  !---------------
  ! If restart alarm is ringing - write restart file
  !---------------
 
  call esmf_clockgetalarm(clock, alarmname='alarm_restart', alarm=alarm, rc=rc)
  if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
      line=__line__, &
      file=__file__)) &
      return  ! bail out
 
  if (esmf_alarmisringing(alarm, rc=rc)) then
     if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
         line=__line__, &
         file=__file__)) &
         return  ! bail out
 
     call esmf_alarmringeroff(alarm, rc=rc )
     if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
         line=__line__, &
         file=__file__)) &
         return  ! bail out
 
     ! call into system specific method to get desired restart filename
     restartname = ""
     call esmf_methodexecute(gcomp, label="GetRestartFileToWrite", &
          existflag=existflag, userrc=userrc, rc=rc)
     if (esmf_logfounderror(rctocheck=rc, msg="Error executing user method to get restart filename", &
         line=__line__, &
         file=__file__)) &
         return  ! bail out
 
     if (esmf_logfounderror(rctocheck=userrc, msg="Error in method to get restart filename", &
          line=__line__, &
          file=__file__)) &
          return  ! bail out
     if (existflag) then
        call esmf_logwrite("MOM_cap: called user GetRestartFileToWrite method", esmf_logmsg_info, rc=rc)
        if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
            line=__line__, &
            file=__file__)) &
            return  ! bail out
        call nuopc_compattributeget(gcomp, name='RestartFileToWrite', &
             ispresent=ispresent, isset=isset, value=cvalue, rc=rc)
        if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
            line=__line__, &
            file=__file__)) &
            return  ! bail out
        if (ispresent .and. isset) then
           restartname = trim(cvalue)
           call esmf_logwrite("MOM_cap: User RestartFileToWrite: "//trim(restartname), esmf_logmsg_info, rc=rc)
           if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
               line=__line__, &
               file=__file__)) &
               return  ! bail out
        endif
     endif
 
     if (len_trim(restartname) == 0) then
        ! none provided, so use a default restart filename
        call esmf_clockgetnexttime(clock, mytime, rc=rc)
        if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
            line=__line__, &
            file=__file__)) &
            return  ! bail out
        call esmf_timeget (mytime, yy=year, mm=month, dd=day, &
             h=hour, m=minute, s=seconds, rc=rc )
        if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
            line=__line__, &
            file=__file__)) &
            return  ! bail out
        write(restartname,'(A,".mom6.r.",I4.4,"-",I2.2,"-",I2.2,"-",I2.2,"-",I2.2,"-",I2.2)') &
              "ocn", year, month, day, hour, minute, seconds
        call esmf_logwrite("MOM_cap: Using default restart filename:  "//trim(restartname), esmf_logmsg_info, rc=rc)
        if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
            line=__line__, &
            file=__file__)) &
            return  ! bail out
     endif
 
     ! TODO: address if this requirement is being met for the DA group
     ! Optionally write restart files when currTime-startTime is integer multiples of restart_interval
     ! if (restart_interval > 0 ) then
     !   time_elapsed = currTime - startTime
     !   call ESMF_TimeIntervalGet(time_elapsed, s_i8=time_elapsed_sec, rc=rc)
     !   if (ESMF_LogFoundError(rcToCheck=rc, msg=ESMF_LOGERR_PASSTHRU, &
     !     line=__LINE__, &
     !     file=__FILE__)) &
     !     return  ! bail out
     !   n_interval = time_elapsed_sec / restart_interval
     !   if ((n_interval .gt. 0) .and. (n_interval*restart_interval == time_elapsed_sec)) then
     !       time_restart_current = esmf2fms_time(currTime)
     !       timestamp = date_to_string(time_restart_current)
     !       call ESMF_LogWrite("MOM: Writing restart at "//trim(timestamp), ESMF_LOGMSG_INFO, rc=rc)
     !       write(*,*) 'calling ocean_model_restart'
     !       call ocean_model_restart(ocean_state, timestamp)
     !   endif
     ! endif
 
     ! write restart file(s)
     call ocean_model_restart(ocean_state, restartname=restartname)
 
     if (is_root_pe()) then
       write(logunit,*) subname//' writing restart file ',trim(restartname)
     endif
  endif
 
  !---------------
  ! Write diagnostics
  !---------------
 
  if (write_diagnostics) then
     call nuopc_write(exportstate, filenameprefix='field_ocn_export_', &
          overwrite=overwrite_timeslice,timeslice=export_slice, relaxedflag=.true., rc=rc)
     if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
         line=__line__, &
         file=__file__)) &
         return  ! bail out
     export_slice = export_slice + 1
  endif
 
  if(profile_memory) call esmf_vmlogmeminfo("Leaving MOM Model_ADVANCE: ")
 
end subroutine modeladvance
 
 
subroutine modelsetrunclock(gcomp, rc)
  type(esmf_gridcomp)  :: gcomp
  integer, intent(out) :: rc
 
  ! local variables
  type(esmf_clock)         :: mclock, dclock
  type(esmf_time)          :: mcurrtime, dcurrtime
  type(esmf_time)          :: mstoptime
  type(esmf_timeinterval)  :: mtimestep, dtimestep
  character(len=128)       :: mtimestring, dtimestring
  character(len=256)       :: cvalue
  character(len=256)       :: restart_option ! Restart option units
  integer                  :: restart_n      ! Number until restart interval
  integer                  :: restart_ymd    ! Restart date (YYYYMMDD)
  type(esmf_alarm)         :: restart_alarm
  logical                  :: isPresent, isSet
  logical                  :: first_time = .true.
  character(len=*),parameter :: subname='MOM_cap:(ModelSetRunClock) '
  !--------------------------------
 
  rc = esmf_success
 
  ! query the Component for its clock, importState and exportState
  call nuopc_modelget(gcomp, driverclock=dclock, modelclock=mclock, rc=rc)
  if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
    line=__line__, &
    file=__file__)) &
    return  ! bail out
 
  call esmf_clockget(dclock, currtime=dcurrtime, timestep=dtimestep, rc=rc)
  if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
    line=__line__, &
    file=__file__)) &
    return  ! bail out
 
  call esmf_clockget(mclock, currtime=mcurrtime, timestep=mtimestep, rc=rc)
  if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
    line=__line__, &
    file=__file__)) &
    return  ! bail out
 
  !--------------------------------
  ! check that the current time in the model and driver are the same
  !--------------------------------
 
  if (mcurrtime /= dcurrtime) then
    call esmf_timeget(dcurrtime, timestring=dtimestring, rc=rc)
    if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
      line=__line__, &
      file=__file__)) &
      return  ! bail out
 
    call esmf_timeget(mcurrtime, timestring=mtimestring, rc=rc)
    if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
      line=__line__, &
      file=__file__)) &
      return  ! bail out
 
    call esmf_logseterror(esmf_rc_val_wrong, &
         msg=subname//": ERROR in time consistency: "//trim(dtimestring)//" != "//trim(mtimestring),  &
         line=__line__, file=__file__, rctoreturn=rc)
    return
  endif
 
  !--------------------------------
  ! force model clock currtime and timestep to match driver and set stoptime
  !--------------------------------
 
  mstoptime = mcurrtime + dtimestep
 
  call esmf_clockset(mclock, currtime=dcurrtime, timestep=dtimestep, stoptime=mstoptime, rc=rc)
  if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
    line=__line__, &
    file=__file__)) &
    return  ! bail out
 
  if (first_time) then
     !--------------------------------
     ! set restart alarm
     !--------------------------------
 
     ! defaults
     restart_n = 0
     restart_ymd = 0
 
     call nuopc_compattributeget(gcomp, name="restart_option", ispresent=ispresent, &
          isset=isset, value=restart_option, rc=rc)
     if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
          line=__line__, &
          file=__file__)) &
          return  ! bail out
     if (ispresent .and. isset) then
        call nuopc_compattributeget(gcomp,  name="restart_n", value=cvalue, &
             ispresent=ispresent, isset=isset, rc=rc)
        if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
             line=__line__, &
             file=__file__)) &
             return  ! bail out
        if (ispresent .and. isset) then
           read(cvalue,*) restart_n
        endif
        call nuopc_compattributeget(gcomp, name="restart_ymd", value=cvalue, &
             ispresent=ispresent, isset=isset, rc=rc)
        if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
             line=__line__, &
             file=__file__)) &
             return  ! bail out
        if (ispresent .and. isset) then
           read(cvalue,*) restart_ymd
        endif
     else
        restart_option = "none"
     endif
 
     call alarminit(mclock, &
          alarm   = restart_alarm,         &
          option  = trim(restart_option),  &
          opt_n   = restart_n,             &
          opt_ymd = restart_ymd,           &
          reftime = mcurrtime,             &
          alarmname = 'alarm_restart', rc=rc)
     if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
          line=__line__, &
          file=__file__)) &
          return  ! bail out
 
     call esmf_alarmset(restart_alarm, clock=mclock, rc=rc)
     if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
          line=__line__, &
          file=__file__)) &
          return  ! bail out
     first_time = .false.
 
     call esmf_logwrite(subname//" Set restart option = "//restart_option, &
          esmf_logmsg_info, rc=rc)
     if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
          line=__line__, &
          file=__file__)) &
          return  ! bail out
 
  endif
 
  !--------------------------------
  ! Advance model clock to trigger alarms then reset model clock back to currtime
  !--------------------------------
 
  call esmf_clockadvance(mclock,rc=rc)
  if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
    line=__line__, &
    file=__file__)) &
    return  ! bail out
 
  call esmf_clockset(mclock, currtime=dcurrtime, timestep=dtimestep, stoptime=mstoptime, rc=rc)
  if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
    line=__line__, &
    file=__file__)) &
    return  ! bail out
 
end subroutine modelsetrunclock
 
 
!===============================================================================
 
!> Called by NUOPC at the end of the run to clean up.
!!
!! @param gcomp an ESMF_GridComp object
!! @param rc return code
subroutine ocean_model_finalize(gcomp, rc)
 
  type(esmf_gridcomp)  :: gcomp !< ESMF_GridComp object
  integer, intent(out) :: rc    !< return code
 
  ! local variables
  type (ocean_public_type),      pointer :: ocean_public
  type (ocean_state_type),       pointer :: ocean_state
  type(ocean_internalstate_wrapper)      :: ocean_internalstate
  type(time_type)                        :: Time
  type(esmf_clock)                       :: clock
  type(esmf_time)                        :: currTime
  character(len=64)                      :: timestamp
  character(len=*),parameter  :: subname='(MOM_cap:ocean_model_finalize)'
 
  write(*,*) 'MOM: --- finalize called ---'
  rc = esmf_success
 
  call esmf_gridcompgetinternalstate(gcomp, ocean_internalstate, rc)
  if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
    line=__line__, &
    file=__file__)) &
    return  ! bail out
 
  ocean_public => ocean_internalstate%ptr%ocean_public_type_ptr
  ocean_state  => ocean_internalstate%ptr%ocean_state_type_ptr
 
  call nuopc_modelget(gcomp, modelclock=clock, rc=rc)
  if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
    line=__line__, &
    file=__file__)) &
    return  ! bail out
 
  call esmf_clockget(clock, currtime=currtime, rc=rc)
  if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
    line=__line__, &
    file=__file__)) &
    return  ! bail out
  time = esmf2fms_time(currtime)
 
  if (cesm_coupled) then
     call ocean_model_end(ocean_public, ocean_state, time, write_restart=.false.)
  else
     call ocean_model_end(ocean_public, ocean_state, time, write_restart=.true.)
  endif
  call field_manager_end()
 
  call fms_io_exit()
  call fms_end()
 
  write(*,*) 'MOM: --- completed ---'
 
end subroutine ocean_model_finalize
 
 
!> Set scalar data from state for a particula name
subroutine state_setscalar(value, scalar_id, State, mytask, scalar_name, scalar_count,  rc)
  real(ESMF_KIND_R8),intent(in)     :: value
  integer,           intent(in)     :: scalar_id
  type(esmf_state),  intent(inout)  :: State
  integer,           intent(in)     :: mytask
  character(len=*),  intent(in)     :: scalar_name
  integer,           intent(in)     :: scalar_count
  integer,           intent(inout)  :: rc           !< return code
 
  ! local variables
  type(esmf_field)                :: field
  real(ESMF_KIND_R8), pointer     :: farrayptr(:,:)
  character(len=*), parameter     :: subname='(MOM_cap:State_SetScalar)'
  !--------------------------------------------------------
 
  rc = esmf_success
 
  call esmf_stateget(state, itemname=trim(scalar_name), field=field, rc=rc)
  if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, line=__line__, file=u_file_u)) return
 
  if (mytask == 0) then
    call esmf_fieldget(field, farrayptr=farrayptr, rc=rc)
    if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, line=__line__, file=u_file_u)) return
 
    if (scalar_id < 0 .or. scalar_id > scalar_count) then
       call esmf_logseterror(esmf_rc_arg_bad, &
            msg=subname//": ERROR in scalar_id", &
            line=__line__, file=__file__, rctoreturn=rc)
       return
    endif
 
    farrayptr(scalar_id,1) = value
  endif
 
end subroutine state_setscalar
 
!> Realize the import and export fields using either a grid or a mesh.
subroutine mom_realizefields(state, nfields, field_defs, tag, grid, mesh, rc)
  type(esmf_state)    , intent(inout)        :: state !< ESMF_State object for
                                                      !! import/export fields.
  integer             , intent(in)           :: nfields !< Number of fields.
  type(fld_list_type) , intent(inout)        :: field_defs(:) !< Structure with field's
                                                              !! information.
  character(len=*)    , intent(in)           :: tag !< Import or export.
  type(esmf_grid)     , intent(in), optional :: grid!< ESMF grid.
  type(esmf_mesh)     , intent(in), optional :: mesh!< ESMF mesh.
  integer             , intent(inout)        :: rc  !< Return code.
 
  ! local variables
  integer                     :: i
  type(esmf_field)            :: field
  real(ESMF_KIND_R8), pointer :: fldptr1d(:)   ! for mesh
  real(ESMF_KIND_R8), pointer :: fldptr2d(:,:) ! for grid
  character(len=*),parameter  :: subname='(MOM_cap:MOM_RealizeFields)'
  !--------------------------------------------------------
 
  rc = esmf_success
 
  do i = 1, nfields
 
    if (nuopc_isconnected(state, fieldname=field_defs(i)%shortname)) then
 
      if (field_defs(i)%shortname == scalar_field_name) then
 
        call esmf_logwrite(subname // tag // " Field "// trim(field_defs(i)%stdname) // " is connected on root pe.", &
          esmf_logmsg_info, &
          line=__line__, &
          file=__file__, &
          rc=rc)
 
        call setscalarfield(field, rc)
        if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
          line=__line__, &
          file=__file__)) &
          return  ! bail out
 
      else
 
        call esmf_logwrite(subname // tag // " Field "// trim(field_defs(i)%stdname) // " is connected.", &
          esmf_logmsg_info, &
          line=__line__, &
          file=__file__, &
          rc=rc)
 
        if (present(grid)) then
 
           field = esmf_fieldcreate(grid, esmf_typekind_r8, indexflag=esmf_index_delocal, &
                name=field_defs(i)%shortname, rc=rc)
           if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
                line=__line__, &
                file=__file__)) &
                return  ! bail out
 
           ! initialize fldptr to zero
           call esmf_fieldget(field, farrayptr=fldptr2d, rc=rc)
           if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
                line=__line__, &
                file=__file__)) &
                return  ! bail out
           fldptr2d(:,:) = 0.0
 
        else if (present(mesh)) then
 
           field = esmf_fieldcreate(mesh=mesh, typekind=esmf_typekind_r8, meshloc=esmf_meshloc_element, &
                name=field_defs(i)%shortname, rc=rc)
           if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
                line=__line__, &
                file=__file__)) &
                return  ! bail out
 
           ! initialize fldptr to zero
           call esmf_fieldget(field, farrayptr=fldptr1d, rc=rc)
           if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
                line=__line__, &
                file=__file__)) &
                return  ! bail out
           fldptr1d(:) = 0.0
 
        endif
 
      endif
 
      ! Realize connected field
      call nuopc_realize(state, field=field, rc=rc)
      if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
        line=__line__, &
        file=__file__)) &
        return  ! bail out
 
    else ! field is not connected
 
      call esmf_logwrite(subname // tag // " Field "// trim(field_defs(i)%stdname) // " is not connected.", &
        esmf_logmsg_info, &
        line=__line__, &
        file=__file__, &
        rc=rc)
      ! remove a not connected Field from State
      call esmf_stateremove(state, (/field_defs(i)%shortname/), rc=rc)
      if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
        line=__line__, &
        file=__file__)) &
        return  ! bail out
 
    endif
 
  enddo
 
contains  !- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 
  subroutine setscalarfield(field, rc)
 
    ! create a field with scalar data on the root pe
    type(esmf_field), intent(inout)  :: field
    integer,          intent(inout)  :: rc
 
    ! local variables
    type(esmf_distgrid) :: distgrid
    type(esmf_grid)     :: grid
    character(len=*), parameter :: subname='(MOM_cap:SetScalarField)'
 
    rc = esmf_success
 
    ! create a DistGrid with a single index space element, which gets mapped onto DE 0.
    distgrid = esmf_distgridcreate(minindex=(/1/), maxindex=(/1/), rc=rc)
    if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
        line=__line__, &
        file=__file__)) &
        return  ! bail out
 
    grid = esmf_gridcreate(distgrid, rc=rc)
    if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
        line=__line__, &
        file=__file__)) &
        return  ! bail out
 
    ! num of scalar values
    field = esmf_fieldcreate(name=trim(scalar_field_name), grid=grid, typekind=esmf_typekind_r8, &
         ungriddedlbound=(/1/), ungriddedubound=(/scalar_field_count/), gridtofieldmap=(/2/), rc=rc)
    if (esmf_logfounderror(rctocheck=rc, msg=esmf_logerr_passthru, &
        line=__line__, &
        file=__file__)) &
        return  ! bail out
 
  end subroutine setscalarfield
 
end subroutine mom_realizefields
 
!===============================================================================
 
!> Set up list of field information
subroutine fld_list_add(num, fldlist, stdname, transferOffer, shortname)
  integer,                    intent(inout) :: num
  type(fld_list_type),        intent(inout) :: fldlist(:)
  character(len=*),           intent(in)    :: stdname
  character(len=*),           intent(in)    :: transferOffer
  character(len=*), optional, intent(in)    :: shortname
 
  ! local variables
  integer :: rc
  character(len=*), parameter :: subname='(MOM_cap:fld_list_add)'
 
  ! fill in the new entry
  num = num + 1
  if (num > fldsmax) then
     call esmf_logseterror(esmf_rc_val_outofrange, &
          msg=trim(subname)//": ERROR number of field exceeded fldsMax: "//trim(stdname), &
          line=__line__, file=__file__, rctoreturn=rc)
     return
  endif
 
  fldlist(num)%stdname        = trim(stdname)
  if (present(shortname)) then
     fldlist(num)%shortname   = trim(shortname)
  else
     fldlist(num)%shortname   = trim(stdname)
  endif
  fldlist(num)%transferOffer  = trim(transferoffer)
 
end subroutine fld_list_add
 
 
#ifndef CESMCOUPLED
subroutine shr_file_setlogunit(nunit)
  integer, intent(in) :: nunit
  ! do nothing for this stub - its just here to replace
  ! having cppdefs in the main program
end subroutine shr_file_setlogunit
 
subroutine shr_file_getlogunit(nunit)
  integer, intent(in) :: nunit
  ! do nothing for this stub - its just here to replace
  ! having cppdefs in the main program
end subroutine shr_file_getlogunit
#endif
 
!>
!! @page nuopc_cap NUOPC Cap
!! @author Fei Liu (fei.liu@gmail.com)
!! @date 5/10/13 Original documentation
!! @author Rocky Dunlap (rocky.dunlap@noaa.gov)
!! @date 1/12/17 Moved to doxygen
!! @date 2/28/19 Rewrote for unified cap
!! @tableofcontents
!!
!! @section Overview Overview
!!
!! **This MOM cap has been tested with MOM6.**
!!
!! This document describes the MOM NUOPC "cap", which is a light weight software layer that is
!! required when the [MOM ocean model](https://github.com/NOAA-GFDL/MOM6/tree/dev/master)
!! is used in [National Unified Operation Prediction Capability]
!! (http://www.earthsystemcog.org/projects/nuopc) (NUOPC) coupled systems. Also see the
!! [MOM wiki](https://github.com/NOAA-GFDL/MOM6-Examples/wiki) for more documentation.
!!
!! NUOPC is a software layer built on top of the [Earth System Modeling
!! Framework] (https://www.earthsystemcog.org/projects/esmf) (ESMF).
!! ESMF is a high-performance modeling framework that provides
!! data structures, interfaces, and operations suited for building coupled models
!! from a set of components. NUOPC refines the capabilities of ESMF by providing
!! a more precise definition of what it means for a model to be a component and
!! how components should interact and share data in a coupled system. The NUOPC
!! Layer software is designed to work with typical high-performance models in the
!! Earth sciences domain, most of which are written in Fortran and are based on a
!! distributed memory model of parallelism (MPI).
!!
!! A NUOPC "cap" is a Fortran module that serves as the interface to a model
!! when it's used in a NUOPC-based coupled system.
!! The term "cap" is used because it is a light weight software layer that sits on top
!! of model code, making calls into it and exposing model data structures in a
!! standard way.
!!
!! The MOM cap package includes the cap code itself (MOM_cap.F90, MOM_cap_methods.F90
!! and MOM_cap_time.F90), a set of time utilities (time_utils.F90) for converting between ESMF and FMS
!! time type and two modules MOM_ocean_model_nuopc.F90 and MOM_surface_forcing_nuopc.F90. MOM_surface_forcing_nuopc.F90
!! converts the input ESMF data (import data) to a MOM-specific data type (surface_forcing_CS).
!! MOM_ocean_model_nuopc.F90 contains routines for initialization, update and finalization of the ocean model state.
!!
!! @subsection CapSubroutines Cap Subroutines
!!
!! The MOM cap modules contains a set of subroutines that are required
!! by NUOPC.  These subroutines are called by the NUOPC infrastructure according
!! to a predefined calling sequence.  Some subroutines are called during
!! initialization of the coupled system, some during the run of the coupled
!! system, and some during finalization of the coupled system.
!!
!! The initialization sequence is the most complex and is governed by the NUOPC technical rules.
!! Details about the initialization sequence can be found in the [NUOPC Reference Manual]
!! (http://www.earthsystemmodeling.org/esmf_releases/last_built/NUOPC_refdoc/).
!! The cap requires beta snapshot ESMF v8.0.0bs16 or later.
!!
!! The following table summarizes the NUOPC-required subroutines that appear in the
!! MOM cap.  The "Phase" column says whether the subroutine is called during the
!! initialization, run, or finalize part of the coupled system run.
!!
!!<table>
!!<tr><th> Phase  <th> MOM Cap Subroutine  <th> Description
!!<tr>
!!  <td> Init
!!  <td> [InitializeP0] (@ref MOM_cap_mod::initializep0)
!!  <td> Sets the Initialize Phase Definition (IPD) version to use
!!<tr>
!!  <td> Init
!!  <td> [InitializeAdvertise] (@ref MOM_cap_mod::initializeadvertise)
!!  <td> Advertises standard names of import and export fields
!!<tr>
!!  <td> Init
!!  <td> [InitializeRealize] (@ref MOM_cap_mod::initializerealize)
!!  <td> Creates an ESMF_Grid or ESMF_Mesh as well as ESMF_Fields for import and export fields
!!<tr>
!!  <td> Run
!!  <td> [ModelAdvance] (@ref MOM_cap_mod::modeladvance)
!!  <td> Advances the model by a timestep
!!<tr>
!!  <td> Final
!!  <td> [Finalize] (@ref MOM_cap_mod::ocean_model_finalize)
!!  <td> Cleans up
!!</table>
!!
!!
!! @section UnderlyingModelInterfaces Underlying Model Interfaces
!!
!!
!! @subsection DomainCreation Domain Creation
!!
!! The cap can accomodate a MOM tripolar grid which is represented either as a 2D `ESMF_Grid` or
!! as a 1D `ESMF_Mesh`. Other MOM grids (e.g. a bipolar grid) can be represented as a 1d `ESMF_Mesh` only.
!! Coupling fields are placed on either the `ESMF_Grid` or `ESMF_Mesh`.
!! Note that for either the `ESMF_Grid` or `ESMF_Mesh` representation, the fields are translated into
!! a 2D MOM specific surface boundary type and the distinction between the two is no longer there.
!! Calls related to creating the grid are located in the [InitializeRealize]
!! (@ref MOM_cap_mod::initializerealize) subroutine, which is called by the NUOPC infrastructure
!! during the intialization sequence.
!!
!! The cap determines parameters for setting up the grid by calling subroutines in the
!! `mpp_domains_mod` module. The global domain size is determined by calling `mpp_get_global_domain()`.
!! A check is in place to ensure that there is only a single tile in the domain (the
!! cap is currently limited to one tile; multi-tile mosaics are not supported).  The
!! decomposition across processors is determined via calls to `mpp_get_compute_domains()`
!! (to retrieve decomposition block indices) and `mpp_get_pelist()` (to determine how
!! blocks are assigned to processors).
!!
!! The `ESMF_Grid` is created in several steps:
!!  - an `ESMF_DELayout` is created based on the pelist from MOM
!!  - an `ESMF_DistGrid` is created over the global index space. Connections are set
!!    up so that the index space is periodic in the first dimension and has a
!!    fold at the top for the bipole. The decompostion blocks are also passed in
!!    along with the `ESMF_DELayout` mentioned above.
!!  - an `ESMF_Grid` is then created by passing in the above `ESMF_DistGrid`.
!!  - masks, areas, center (tlat, tlon), and corner (ulat, ulon) coordinates are then added to the `ESMF_Grid`
!!    by retrieving those fields from the MOM datatype `ocean_grid` elements.
!!
!! The `ESMF_Mesh` is also created in several steps:
!!   - the target mesh is generated offline.
!!   - a temporary mesh is created from an input file specified by the config variable `mesh_ocn`.
!!     the mesh has a distribution that is automatically generated by ESMF when reading in the mesh
!!   - an `ESMF_DistGrid` is created from the global index space for the computational domain.
!!   - the final `ESMF_Mesh` is then created by distributing the temporary mesh using the created `ESMF_DistGrid`.
!!
!!
!! @subsection Initialization Initialization
!!
!! During the [InitializeAdvertise] (@ref MOM_cap_mod::initializeadvertise) phase, calls are
!! made to MOM's native initialization subroutines, including `fms_init()`, `constants_init()`,
!! `field_manager_init()`, `diag_manager_init()`, and `set_calendar_type()`.  The MPI communicator
!! is pulled in through the ESMF VM object for the MOM component. The dt and start time are set
!! from parameters from the incoming ESMF clock with calls to `set_time()` and `set_date().`
!!
!!
!! @subsection Run Run
!!
!! The [ModelAdvance] (@ref MOM_cap_mod::modeladvance) subroutine is called by the NUOPC
!! infrastructure when it's time for MOM to advance in time. During this subroutine, there is a
!! call into the MOM update routine:
!!
!!      call update_ocean_model(Ice_ocean_boundary, Ocean_state, Ocean_public, Time, Time_step_coupled)
!!
!! Priori to the call to `update_ocean_model()`, the cap performs these steps
!! - the `Time` and `Time_step_coupled` parameters, based on FMS types, are derived from the incoming ESMF clock
!! - diagnostics are optionally written to files `field_ocn_import_*`, one for each import field
!! - mom_import is called and translates to the ESMF input data to a MOM specific data type
!!    - momentum flux vectors are rotated to internal grid
!!
!! After the call to `update_ocean_model()`, the cap performs these steps:
!! - mom_export is called
!!   - the `ocean_mask` export is set to match that of the internal MOM mask
!!   - the `freezing_melting_potential` export is converted from J m-2 to W m-2 by dividing by the coupling interval
!!   - vector rotations are applied to the `ocean_current_zonal` and `ocean_current_merid` exports, back to lat-lon grid
!!   - diagnostics are optionally written to files `field_ocn_export_*`, one for each export field
!!   - optionally, a call is made to `ocean_model_restart()` at the interval `restart_interval`
!!
!! @subsubsection VectorRotations Vector Rotations
!!
!! Vector rotations are applied to incoming momentum fluxes (from regular lat-lon to tripolar grid) and
!! outgoing ocean currents (from tripolar to regular lat-lon). The rotation angles are provided
!! from the native MOM grid by a call to `get_ocean_grid(Ocean_grid)`.
!! The cosine and sine of the rotation angle are:
!!
!!     ocean_grid%cos_rot(i,j)
!!     ocean_grid%sin_rot(i,j)
!!
!! The rotation of momentum flux from regular lat-lon to tripolar is:
!! \f[
!! \begin{bmatrix}
!! \tau_x' \\
!! \tau_y'
!! \end{bmatrix} =
!! \begin{bmatrix}
!!  cos \theta   & sin \theta \\
!!  -sin \theta  & cos \theta
!! \end{bmatrix} *
!! \begin{bmatrix}
!! \tau_x \\
!! \tau_y
!! \end{bmatrix}
!! \f]
!!
!! The rotation of ocean current from tripolar to regular lat-lon is:
!! \f[
!! \begin{bmatrix}
!! u' \\
!! v'
!! \end{bmatrix} =
!! \begin{bmatrix}
!!  cos \theta   & -sin \theta \\
!!  sin \theta  & cos \theta
!! \end{bmatrix} *
!! \begin{bmatrix}
!! u \\
!! v
!! \end{bmatrix}
!! \f]
!! @subsection Finalization Finalization
!!
!! NUOPC infrastructure calls [ocean_model_finalize] (@ref MOM_cap_mod::ocean_model_finalize)
!! at the end of the run. This subroutine is a hook to call into MOM's native shutdown
!! procedures:
!!
!!     call ocean_model_end (ocean_public, ocean_State, Time)
!!     call diag_manager_end(Time )
!!     call field_manager_end
!!     call fms_io_exit
!!     call fms_end
!!
!! @section ModelFields Model Fields
!!
!! The following tables list the import and export fields currently set up in the MOM cap.
!!
!! @subsection ImportFields Import Fields
!!
!! <table>
!! <tr>
!!     <th>Standard Name</td>
!!     <th>Units</td>
!!     <th>Model Variable</td>
!!     <th>Description</td>
!!     <th>Notes</td>
!! <tr>
!!     <td>inst_pres_height_surface</td>
!!     <td>Pa</td>
!!     <td>p</td>
!!     <td>pressure of overlying sea ice and atmosphere</td>
!!     <td></td>
!! </tr>
!! <tr>
!!     <td>mass_of_overlying_sea_ice</td>
!!     <td>kg</td>
!!     <td>mi</td>
!!     <td>mass of overlying sea ice</td>
!!     <td></td>
!! </tr>
!! <tr>
!!     <td>seaice_melt_heat</td>
!!     <td>W m-2</td>
!!     <td>seaice_melt_heat</td>
!!     <td>sea ice and snow melt heat flux</td>
!!     <td></td>
!! </tr>
!! <tr>
!!     <td>seaice_melt</td>
!!     <td>kg m-2 s-1</td>
!!     <td>seaice_melt</td>
!!     <td>water flux due to sea ice and snow melting</td>
!!     <td></td>
!! </tr>
!! <tr>
!!     <td>mean_calving_heat_flx</td>
!!     <td>W m-2</td>
!!     <td>calving_hflx</td>
!!     <td>heat flux, relative to 0C, of frozen land water into ocean</td>
!!     <td></td>
!! </tr>
!! <tr>
!!     <td>mean_calving_rate</td>
!!     <td>kg m-2 s-1</td>
!!     <td>calving</td>
!!     <td>mass flux of frozen runoff</td>
!!     <td></td>
!! </tr>
!! <tr>
!!     <td>mean_evap_rate</td>
!!     <td>kg m-2 s-1</td>
!!     <td>q_flux</td>
!!     <td>specific humidity flux</td>
!!     <td></td>
!! </tr>
!! <tr>
!!     <td>mean_fprec_rate</td>
!!     <td>kg m-2 s-1</td>
!!     <td>fprec</td>
!!     <td>mass flux of frozen precip</td>
!!     <td></td>
!! </tr>
!! <tr>
!!     <td>mean_merid_moment_flx</td>
!!     <td>Pa</td>
!!     <td>v_flux</td>
!!     <td>j-directed wind stress into ocean</td>
!!     <td>[vector rotation] (@ref VectorRotations) applied - lat-lon to tripolar</td>
!! </tr>
!! <tr>
!!     <td>mean_net_lw_flx</td>
!!     <td>W m-2</td>
!!     <td>lw_flux</td>
!!     <td>long wave radiation</td>
!!     <td></td>
!! </tr>
!! <tr>
!!     <td>mean_net_sw_ir_dif_flx</td>
!!     <td>W m-2</td>
!!     <td>sw_flux_nir_dif</td>
!!     <td>diffuse near IR shortwave radiation</td>
!!     <td></td>
!! </tr>
!! <tr>
!!     <td>mean_net_sw_ir_dir_flx</td>
!!     <td>W m-2</td>
!!     <td>sw_flux_nir_dir</td>
!!     <td>direct near IR shortwave radiation</td>
!!     <td></td>
!! </tr>
!! <tr>
!!     <td>mean_net_sw_vis_dif_flx</td>
!!     <td>W m-2</td>
!!     <td>sw_flux_vis_dif</td>
!!     <td>diffuse visible shortware radiation</td>
!!     <td></td>
!! </tr>
!! <tr>
!!     <td>mean_net_sw_vis_dir_flx</td>
!!     <td>W m-2</td>
!!     <td>sw_flux_vis_dir</td>
!!     <td>direct visible shortware radiation</td>
!!     <td></td>
!! </tr>
!! <tr>
!!     <td>mean_prec_rate</td>
!!     <td>kg m-2 s-1</td>
!!     <td>lprec</td>
!!     <td>mass flux of liquid precip</td>
!!     <td></td>
!! </tr>
!! <tr>
!!     <td>mean_runoff_heat_flx</td>
!!     <td>W m-2</td>
!!     <td>runoff_hflx</td>
!!     <td>heat flux, relative to 0C, of liquid land water into ocean</td>
!!     <td></td>
!! </tr>
!! <tr>
!!     <td>mean_runoff_rate</td>
!!     <td>kg m-2 s-1</td>
!!     <td>runoff</td>
!!     <td>mass flux of liquid runoff</td>
!!     <td></td>
!! </tr>
!! <tr>
!!     <td>mean_salt_rate</td>
!!     <td>kg m-2 s-1</td>
!!     <td>salt_flux</td>
!!     <td>salt flux</td>
!!     <td></td>
!! </tr>
!! <tr>
!!     <td>mean_sensi_heat_flx</td>
!!     <td>W m-2</td>
!!     <td>t_flux</td>
!!     <td>sensible heat flux into ocean</td>
!!     <td></td>
!! </tr>
!! <tr>
!!     <td>mean_zonal_moment_flx</td>
!!     <td>Pa</td>
!!     <td>u_flux</td>
!!     <td>i-directed wind stress into ocean</td>
!!     <td>[vector rotation] (@ref VectorRotations) applied - lat-lon to tripolar</td>
!! </tr>
!! </table>
!!
!! @subsection ExportField Export Fields
!!
!! Export fields are populated from the `ocean_public` parameter (type `ocean_public_type`)
!! after the call to `update_ocean_model()`.
!!
!! <table>
!!   <tr>
!!       <th>Standard Name</th>
!!       <th>Units</th>
!!       <th>Model Variable</th>
!!       <th>Description</th>
!!       <th>Notes</th>
!!   </tr>
!!   <tr>
!!       <td>freezing_melting_potential</td>
!!       <td>W m-2</td>
!!       <td>combination of frazil and melt_potential</td>
!!       <td>cap converts model units (J m-2) to (W m-2) for export</td>
!!       <td></td>
!!   </tr>
!!   <tr>
!!       <td>ocean_mask</td>
!!       <td></td>
!!       <td></td>
!!       <td>ocean mask</td>
!!       <td></td>
!!   </tr>
!!   <tr>
!!       <td>ocn_current_merid</td>
!!       <td>m s-1</td>
!!       <td>v_surf</td>
!!       <td>j-directed surface velocity on u-cell</td>
!!       <td>[vector rotation] (@ref VectorRotations) applied - tripolar to lat-lon</td>
!!   </tr>
!!   <tr>
!!       <td>ocn_current_zonal</td>
!!       <td>m s-1</td>
!!       <td>u_surf</td>
!!       <td>i-directed surface velocity on u-cell</td>
!!       <td>[vector rotation] (@ref VectorRotations) applied - tripolar to lat-lon</td>
!!   </tr>
!!   <tr>
!!       <td>s_surf</td>
!!       <td>psu</td>
!!       <td>s_surf</td>
!!       <td>sea surface salinity on t-cell</td>
!!       <td></td>
!!   </tr>
!!   <tr>
!!       <td>sea_surface_temperature</td>
!!       <td>K</td>
!!       <td>t_surf</td>
!!       <td>sea surface temperature on t-cell</td>
!!       <td></td>
!!   </tr>
!!   <tr>
!!       <td>sea_surface_slope_zonal</td>
!!       <td>unitless</td>
!!       <td>created from ssh</td>
!!       <td>sea surface zonal slope</td>
!!       <td></td>
!!   </tr>
!!   <tr>
!!       <td>sea_surface_slope_merid</td>
!!       <td>unitless</td>
!!       <td>created from ssh</td>
!!       <td>sea surface meridional slope</td>
!!       <td></td>
!!   </tr>
!!   <tr>
!!       <td>so_bldepth</td>
!!       <td>m</td>
!!       <td>obld</td>
!!       <td>ocean surface boundary layer depth</td>
!!       <td></td>
!!   </tr>
!! </table>
!!
!! @subsection MemoryManagement Memory Management
!!
!! The MOM cap has an internal state type with pointers to three
!! types defined by MOM. There is also a small wrapper derived type
!! required to associate an internal state instance
!! with the ESMF/NUOPC component:
!!
!!     type ocean_internalstate_type
!!        type(ocean_public_type),       pointer :: ocean_public_type_ptr
!!        type(ocean_state_type),        pointer :: ocean_state_type_ptr
!!        type(ice_ocean_boundary_type), pointer :: ice_ocean_boundary_type_ptr
!!     end type
!!
!!     type ocean_internalstate_wrapper
!!        type(ocean_internalstate_type), pointer :: ptr
!!     end type
!!
!! The member of type `ocean_public_type` stores ocean surface fields used during the coupling.
!! The member of type `ocean_state_type` is required by the ocean driver,
!! although its internals are private (not to be used by the coupling directly).
!! This type is passed to the ocean init and update routines
!! so that it can maintain state there if desired.
!! The member of type `ice_ocean_boundary_type` is populated by this cap
!! with incoming coupling fields from other components. These three derived types are allocated during the
!! [InitializeAdvertise] (@ref MOM_cap_mod::initializeadvertise) phase.  Also during that
!! phase, the `ice_ocean_boundary` type members are all allocated using bounds retrieved
!! from `mpp_get_compute_domain()`.
!!
!! During the [InitializeRealize] (@ref MOM_cap_mod::initializerealize) phase,
!! `ESMF_Field`s are created for each of the coupling fields in the `ice_ocean_boundary`
!! and `ocean_public_type` members of the internal state. These fields directly reference into the members of
!! the `ice_ocean_boundary` and `ocean_public_type` so that memory-to-memory copies are not required to move
!! data from the cap's import and export states to the memory areas used internally
!! by MOM.
!!
!! @subsection IO I/O
!!
!! The cap can optionally output coupling fields for diagnostic purposes if the ESMF attribute
!! "DumpFields" has been set to "true". In this case the cap will write out NetCDF files
!! with names "field_ocn_import_<fieldname>.nc" and "field_ocn_export_<fieldname>.nc".
!! Additionally, calls will be made to the cap subroutine [dumpMomInternal]
!! (@ref MOM_cap_mod::dumpmominternal) to write out model internal fields to files
!! named "field_ocn_internal_<fieldname>.nc".  In all cases these NetCDF files will
!! contain a time series of field data.
!!
!! @section RuntimeConfiguration Runtime Configuration
!!
!! At runtime, the MOM cap can be configured with several options provided
!! as ESMF attributes.  Attributes can be set in the cap by the NUOPC Driver
!! above this cap, or in some systems ESMF attributes are set by
!! reading in from a configuration file.  The available attributes are:
!!
!! * `DumpFields` - when set to "true", write out diagnostic NetCDF files for import/export/internal fields
!! * `ProfileMemory` - when set to "true", write out memory usage information to the ESMF log files; this
!!    information is written when entering and leaving the [ModelAdvance]
!!    (@ref MOM_cap_mod::modeladvance) subroutine and before and after the call to
!!   `update_ocean_model()`.
!! * `restart_interval` - integer number of seconds indicating the interval at
!!    which to call `ocean_model_restart()`; no restarts written if set to 0
 
end module mom_cap_mod