Design note around Carbon Isotopes read in as streams

[ekluzek]

A few design notes on how to bring Carbon Isotopes in the code as streams.

One change is to store the C13/C14 on the model grid (this is an increase in memory, but it scales with processors).

A common pattern for stream handling is to have: Init, Clean, Advance, and Interp methods, so we use that here.

New namelist data:

• stream_meshfile_atm_c14

• stream_year_first_c14

• stream_year_last_c14

• stream_year_first_c13

• stream_year_last_c13

Hardcoded options:

• atm_c14_mapalgo (hardcode this to nn for now)
• atm_c14_tintalgo (hardcode this to linear for now)
• atm_c14_taxmode (hardcode this to extend for now)
• atm_c13_mapalgo (hardcode this to nn for now)
• atm_c13_tintalgo (hardcode this to linear for now)
• atm_c13_taxmode (hardcode this to extend for now)

New files:

• src/cpl/share_esmf/CarbonIsotopeStreamType.F90

• Description: Carbon isotope stream data for C13 and C14

• Data:

  • with delta_c13_stream_type, delta_c14_stream_type
  • g_to_ig index array private and local
  • Have the data in here have the same units as the dataset, in the deltac13co2_in_air and Delta14cos_in_air units

• Methods: (both delta_c13_stream_type and delta_c14_stream_type

  • Init
  • Clean
  • Advance
  • Interp
  • Move the check_units subroutine from CNCIsoAtmTimeSeriesReadMod to here (check both units and info)

• unit_test_stubs/share_esmf/CarbonIsotopeStreamType.F90

• Description: Stub version for unit tests

Changes to these files:

• src/biogeochem/CNCIsoAtmTimeSeriesReadMod.F90
• Data:
  • Remove: *_time, time_axis_offset, nsectors_c14 data
  • Add delta_c13_stream, delta_c14_stream instances
  • Changes units from deltac13co2 and Deltac14co2 to model units
• Methods:

  • subroutine C14_init_BombSpike -- most removed -- calls deltac13_stream%Init, delta_c13_stream%Advance

  • subroutine C13_Init_TimeSeries -- most removed -- calls deltac14_stream%Init, delta_c14_stream%Advance

  • subroutine C13TimeSeries -- much removed, call the delta_c13_stream%Advance and delta_c13_stream%Interp methods
    RETURN pointer to deltac13 data(begg:endg)

  • subroutine C14BombSpike -- much removed, call the delta_c14_stream%Advance and delta_c14_stream%Interp methods
    RETURN pointer to deltac14 data(begg:endg)

  • subroutine check_units -- move to CarbonIsotopeStreamType.F90

  • subroutine CIsoAtmReadNML -- (NEW) read in the namelist: carbon_isotope_streams

Changes to:
src/biogeophys/PhotosynthesisMod.F90

• Methods:
  • subroutine PhotosynthesisTotal -- nsectors_c14 removed, rc14_atm and rc13_atm become gridcell arrays: begg:endg
    • remove the latdeg and sector_c14 determination

[ekluzek]

Here's what I'm viewing for the delta_c*_streams_type:

  type, public :: delta_c13_stream_type
     real(r8), allocatable, private :: delta_c13  (:)   !  Delta C13 as read in from the streams file on the model grid
     type(shr_strdata_type), private :: sdat  ! Stream data type
  contains

      ! !PUBLIC MEMBER FUNCTIONS:
      procedure, public :: Init  ! Initialize and read data in
      procedure, public :: Clean  ! Clean and deallocate the object class method
      procedure, public :: CleanDeltaC13Stream ! Clean method for the specific type
      procedure, public :: Advance   ! Advance the streams data to the current model date, store the g_to_ig index array (first time)
      procedure, public :: Interp  ! Update the delta_c13 data based on the streams Advance
      final :: CleanDeltaC13Stream ! Declare the finalization method for the compiler to use

      ! !PRIVATE MEMBER FUNCTIONS:
      procedure, private :: InitAllocate   ! Allocate data

  end type delta_c13_stream_type

[ekluzek]

Some questions:

• Increase in memory is OK? Yes
• check_units in delta_c1?_streams -- should it open the file separate from streams to query global attributes? open the file
• Hardcode mapalgo, taxmode and tintalgo? Yes for now, add a variable for it so could be added later
• Delta_c13/c14 data public (and protected) or private? Private as call returns a pointer
• Delta_c13/c14 data allocatable or pointer? allocatable since begg is 1 now
• Should C14BombSpike/C13TimeSeries return a local array, or should Photosynthesis use the delta_c?_streams data? streams data
• Name of new namelist? carbon_isotope_streams
• Do I have the right names for everything? Especially from the file
• Should there be a base carbon isotope type, with specific extensions for c13/c14? This would remove code duplication
• Does the stream%Advance need to be there and separate from the Interp step?

Some cleanup things that can be done later:

• Move Carbon isotope namelist options out of control_mod? (Since adding more)
• Move the history write of RC1?_CANAIR be moved to CNCIsoAtmTimeSeriesReadMod?
• Document the conversion from/to the Delta format?
  • Add: c14ratio, PDB = 0.0112372, preind_atm_del13c, preind_atm_ratio, c13ratio to history output
  • Add note about the conversion

[ekluzek]

The call to shr_strdat_init_from_inline:

character(20), private, parameter     :: stream_varnames(1) = (/ 'delta14co2_in_air   '/)

! NOTE: Delta14co2_in_air and delta13co2_in_air
.
.
.
    call shr_strdata_init_from_inline(this%sdat,             &
         my_task             = iam,                                  &
         logunit             = iulog,                                &
         compname            = 'LND',                                &
         model_clock         = model_clock,                          &
         model_mesh          = mesh,                                 &
         stream_meshfile     = trim(stream_meshfile_atm_c14),        &   ! NOTE: 'none' for C13
         stream_lev_dimname  = 'null',                               &
         stream_mapalgo      = c14_mapalgo,                 &
         stream_filenames    = (/trim(atm_c14_filename)/), &
         stream_fldlistFile  = stream_varnames, &
         stream_fldListModel = stream_varnames, &
         stream_yearFirst    = stream_year_first_c14,            &
         stream_yearLast     = stream_year_last_c14,             &
         stream_yearAlign    = model_year_align_c14,             &
         stream_offset       = 0,                                    &
         stream_taxmode      = c14_taxmode,                             &
         stream_dtlimit      = 1.0e30_r8,                            &
         stream_tintalgo     = c14_tintalgo,                     &
         stream_name         = 'Carbon isotope C14 time varying data',            &
         rc                  = rc)
    if (ESMF_LogFoundError(rcToCheck=rc, msg=ESMF_LOGERR_PASSTHRU, line=__LINE__, file=__FILE__)) then
       call ESMF_Finalize(endflag=ESMF_END_ABORT)
    end if