Validate the CMOR output of CTSM for CMIP7

[ekluzek]

This comes from @jedwards4b in a discussion on TSS Software. He has a start on a formatter that translates time series data into CMOR format to be used for the CMIP7 simulations. This has the data names and metadata standardized across CMIP7 submissions.

Information on the CMOR standard is here:

https://cmor.llnl.gov

The most pressing thing it seems right now is to figure out how we inform CMOR variables about how they should be area averaged. Right now we don't do area averaging on variables, but some may need this for them to be used in CMIP7.

[ekluzek]

Jim noted:
I have converted my first land variable to cmor format, the result is here: /glade/derecho/scratch/cmip7/CMIP6/CMIP/NCAR/CESM2/esm-piControl-spinup/r1i1p1f1/Lmon/evspsblsoi/gr/evspsblsoi_Lmon_CESM2_esm-piControl-spinup_r1i1p1f1_000101-001012.nc

The original timeseries is: /glade/derecho/scratch/cmip7/archive/timeseries/b.e30_beta06.B1850C_LTso.ne30_t232_wgx3.192.wrkflw.1_32/lnd/hist/b.e30_beta06.B1850C_LTso.ne30_t232_wgx3.192.wrkflw.1.clm2.h0.QSOIL.000101-001012.nc

Please have a look at this file and let me know if anything is missing or you have any questions or concerns.

---

Here's an example dataset that @jedwards4b made for us to evaluate: (NOTE CMIP6 will change to CMIP7 and CLM5 will change to CTSM6 in the final version)

ncdump -h /glade/derecho/scratch/cmip7/CMIP6/CMIP/NCAR/CESM2/esm-piControl-spinup/r1i1p1f1/Lmon/evspsblsoi/gr/evspsblsoi_Lmon_CESM2_esm-piControl-spinup_r1i1p1f1_000101-001012.nc
netcdf evspsblsoi_Lmon_CESM2_esm-piControl-spinup_r1i1p1f1_000101-001012 {
dimensions:
        time = UNLIMITED ; // (120 currently)
        lat = 180 ;
        lon = 360 ;
        bnds = 2 ;
variables:
        double time(time) ;
                time:bounds = "time_bnds" ;
                time:units = "days since 0001-01-01 00:00:00" ;
                time:calendar = "noleap" ;
                time:axis = "T" ;
                time:long_name = "time" ;
                time:standard_name = "time" ;
        double time_bnds(time, bnds) ;
        double lat(lat) ;
                lat:bounds = "lat_bnds" ;
                lat:units = "degrees_north" ;
                lat:axis = "Y" ;
                lat:long_name = "Latitude" ;
                lat:standard_name = "latitude" ;
        double lat_bnds(lat, bnds) ;
        double lon(lon) ;
                lon:bounds = "lon_bnds" ;
                lon:units = "degrees_east" ;
                lon:axis = "X" ;
                lon:long_name = "Longitude" ;
                lon:standard_name = "longitude" ;
        double lon_bnds(lon, bnds) ;
        float evspsblsoi(time, lat, lon) ;
                evspsblsoi:standard_name = "water_evaporation_flux_from_soil" ;
                evspsblsoi:long_name = "Water Evaporation from Soil" ;
                evspsblsoi:comment = "Water evaporation from soil (including sublimation)." ;
                evspsblsoi:units = "kg m-2 s-1" ;
                evspsblsoi:cell_methods = "area: mean where land time: mean" ;
                evspsblsoi:cell_measures = "area: areacella" ;
                evspsblsoi:missing_value = 1.e+20f ;
                evspsblsoi:_FillValue = 1.e+20f ;
                evspsblsoi:history = "2025-09-08T14:50:29Z altered by CMOR: Converted type from \'d\' to \'f\'." ;

// global attributes:
                :Conventions = "CF-1.7 CMIP-6.2" ;
                :activity_id = "CMIP" ;
                :branch_method = "no parent" ;
                :branch_time_in_child = 0. ;
                :branch_time_in_parent = 0. ;
                :creation_date = "2025-09-08T14:50:29Z" ;
                :data_specs_version = "01.00.33" ;
                :experiment = "pre-industrial control simulation with CO2 concentration calculated (spin-up)" ;
                :experiment_id = "esm-piControl-spinup" ;
                :external_variables = "areacella" ;
                :forcing_index = 1 ;
                :frequency = "mon" ;
                :further_info_url = "https://furtherinfo.es-doc.org/CMIP6.NCAR.CESM2.esm-piControl-spinup.none.r1i1p1f1" ;
                :grid = "data on a finite volume 1x1 degree grid interpolated from the native spectral element grid." ;
                :grid_label = "gr" ;
                :history = "2025-09-08T14:50:29Z ;rewrote data to be consistent with CMIP for variable evspsblsoi found in table Lmon." ;
                :initialization_index = 1 ;
                :institution = "National Center for Atmospheric Research, Climate and Global Dynamics Laboratory, 1850 Table Mesa Drive, Boulder, CO 80305, USA" ;
                :institution_id = "NCAR" ;
                :mip_era = "CMIP6" ;
                :nominal_resolution = "100 km" ;
                :parent_experiment_id = "no parent" ;
                :parent_mip_era = "no parent" ;
                :parent_source_id = "no parent" ;
                :parent_time_units = "no parent" ;
                :physics_index = 1 ;
                :product = "model-output" ;
                :project\ PI = "Stephen Yeager" ;
                :realization_index = 1 ;
                :realm = "land" ;
                :references = "https://ncar.ucar.edu/what-we-offer/models/community-earth-system-model-cesm" ;
                :source = "CESM2 (2018): \n",
                        "aerosol: MAM4 (same grid as atmos)\n",
                        "atmos: CAM6 (0.9x1.25 finite volume grid; 288 x 192 longitude/latitude; 32 levels; top level 2.25 mb)\n",
                        "atmosChem: MAM4 (same grid as atmos)\n",
                        "land: CLM5 (same grid as atmos)\n",
                        "landIce: CISM2.1\n",
                        "ocean: POP2 (320x384 longitude/latitude; 60 levels; top grid cell 0-10 m)\n",
                        "ocnBgchem: MARBL (same grid as ocean)\n",
                        "seaIce: CICE5.1 (same grid as ocean)" ;
                :source_id = "CESM2" ;
                :source_type = "AOGCM BGC" ;
                :sub_experiment = "none" ;
                :sub_experiment_id = "none" ;
                :table_id = "Lmon" ;
                :table_info = "Creation Date:(18 November 2020) MD5:1bc130d8458c2f5cf7e45c979681c644" ;
                :title = "CESM2 output prepared for CMIP6" ;
                :tracking_id = "hdl:21.14100/bb0daaab-4db7-4dd0-a86a-0b5f91071e9f" ;
                :variable_id = "evspsblsoi" ;
                :variant_label = "/glade/derecho/scratch/cmip7/CMIP6/CMIP/NCAR/CESM2/esm-piControl-spinup/r1i1p1f1/Lmon/evspsblsoi/gr/evspsblsoi_Lmon_CESM2_esm-piControl-spinup_r1i1p1f1" ;
                :license = "CMIP6 model data produced by the National Center for Atmospheric Research is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License (https://creativecommons.org/licenses/). Consult https://pcmdi.llnl.gov/CMIP6/TermsOfUse for terms of use governing CMIP6 output, including citation requirements and proper acknowledgment. Further information about this data, including some limitations, can be found via the further_info_url (recorded as a global attribute in this file)[ and at https://www.cesm.ucar.edu/working-groups/earth-system]. The data producers and data providers make no warranty, either express or implied, including, but not limited to, warranties of merchantability and fitness for a particular purpose. All liabilities arising from the supply of the information (including any liability arising in negligence) are excluded to the fullest extent permitted by law." ;
                :cmor_version = "3.11.0" ;
}

[ekluzek]

Pinging: @wwieder @olyson @slevis-lmwg

[wwieder]

I'm a little unclear about the statement about area averaging in the subject of this issue, Erik. But in an email to @jedwards4b I did request information about area and landfrac on the regridded 1 degree output to help me evaluate results here. Typically these are provided as separate files in the cmorized data.

[wwieder]

From an email with @jedwards4b , Using weights file /glade/campaign/cesm/cesmdata/inputdata/cpl/gridmaps/ne30pg3/map_ne30pg3_to_1x1d_aave.nc
And a bilinear technique from esmf. The code is in /glade/work/cmip7/e3sm_to_cmip/e3sm_to_cmip/cmor_handlers/regrid_se.py

[wwieder]

Also my response over email:

Great thanks Jim.

A few thoughts.
I got better results using the conservative regridding approach for land variables.
I also found that I needed to use source and destination grid land masks to get the weights to behave nicely.
If it's helpful, see this notebook /glade/u/home/wwieder/python/adf/scripts/regridding/regrid_conservative.ipynb
This approach does end up producing "fuzzy" coastlines, but global and regional fluxes / states seem better preserved, and users can mask out coasts to get nice looking maps.

I'm including @billsacks here too, as he was helpful in thinking about how to do this.

[wwieder]

From conversation with @olyson and @slevis-lmwg today:

• Keith will try using ncremap to do this too:
• Will can try his script and compare all of the above
• Jim I would still need information about landfrac and area on the destination grid