CMOR check failure in formatted AERONET data

[nchawang]

Hi ESMValtool community,

I ran the esmvaltool Aeronet downloaded and formatter and got the esmvaltool CMOR aeronet files, when i run the recipe I get the error pointing to coordinate wl:

UTC [3032115] ERROR   Failed to run preprocessor function 'cmor_check_metadata' on the data
esmvalcore.cmor.check.CMORCheckError: There were errors in variable aod:
 Coordinate lambda550nm has var name wl instead of wavelength
in cube:
atmosphere_optical_thickness_due_to_ambient_aerosol_particles / (1) (time: 386; Station index (arbitrary): 1448)
    Dimension coordinates:
        time                                                             x                               -
        Station index (arbitrary)                                        -                               x
    Auxiliary coordinates:
        height_above_mean_sea_level                                      -                               x
        latitude                                                         -                               x
        longitude                                                        -                               x
        platform_name                                                    -                               x
    Ancillary variables:
        Number of days                                                   x                               x
        number_of_observations                                           x                               x
    Scalar coordinates:
        radiation_wavelength                                        551.0 nm
    Attributes:
        Conventions                                                 'CF-1.7'
        host                                                        'levante3.lvt.dkrz.de'
        mip                                                         'AERmon'
        modeling_realm                                              'atmos'
        project_id                                                  'OBS6'
        reference                                                   'doi not found'
        source                                                      'https://aeronet.gsfc.nasa.gov/new_web/download_all_v3_aod.html'
        tier                                                        '3'
        title                                                       'AERONET data reformatted for ESMValTool v2.13.0.dev88+g781e9b542'
        user                                                        'b383276'
        version                                                     '20250719'
loaded from file 

After checking the netcdf generated from the Aeronet formatter script I see:

        float aod(time, station_index) ;
                aod:_FillValue = 1.e+20f ;
                aod:standard_name = "atmosphere_optical_thickness_due_to_ambient_aerosol_particles" ;
                aod:long_name = "Aerosol Optical Thickness" ;
                aod:units = "1" ;
                aod:coordinates = "elev lat lon station_name wl" ;
                aod:ancillary_variables = "num_days num_points" ;
        double wl ;
                wl:units = "nm" ;
                wl:standard_name = "radiation_wavelength" ;
                wl:long_name = "Wavelength" ;        

I am using the recipe 'recipe_aod_aeronet_assess.yml' just reduced the additional datasets to a single model, Any help in this is much appreciated! :)
I've also attached the error log if that helps!

main_log_debug.txt

[jlenh]

Hmmm it looks like the coordinate lambda550nm does not have the correct attributes as per the corresponding CMOR table (see here). By changing the definition of the coordinate in the cmorizer here to follow the attributes of the CMOR table it should work, in particular the var_name as reported in your error log.

If you don't mind opening a PR for that if that solves your issue, it would be greatly helpful!

[nchawang]

Thanks @jlenh , sure! I have opened a PR (#4131) with the fix for this issue, have a nice day!