Missing height 2m coordinates in GFDL-CM4

[Karen-A-Garcia]

There is a height issue with the GFDL-CM4 historical model with variables requiring height. An example is the hurs:

esmvalcore.cmor.check.CMORCheckError: There were errors in variable hurs:
 height2m: does not exist
in cube:
relative_humidity / (%)             (time: 7300; latitude: 180; longitude: 288)
    Dimension coordinates:
        time                             x               -               -
        latitude                         -               x               -
        longitude                        -               -               x
    Cell methods:
        0                           area: time: mean
    Attributes:
        Conventions                 'CF-1.7 CMIP-6.0 UGRID-1.0'
        activity_id                 'CMIP'
        branch_method               'standard'
        branch_time_in_child        0.0
        branch_time_in_parent       -638385
        contact                     'gfdl.climate.model.info@noaa.gov'
        data_specs_version          '01.00.27'
        experiment                  'historical'
        experiment_id               'historical'
        external_variables          'areacella'
        forcing_index               1
        frequency                   'day'
        further_info_url            'https://furtherinfo.es-doc.org/CMIP6.NOAA-GFDL.GFDL-CM4.historical.non ...'
        grid                        'atmos data regridded from Cubed-sphere (c96) to 180,288; interpolation ...'
        grid_label                  'gr1'
        initialization_index        1
        institution                 'National Oceanic and Atmospheric Administration, Geophysical Fluid Dynamics ...'
        institution_id              'NOAA-GFDL'
        interp_method               'conserve_order2'
        license                     'CMIP6 model data produced by NOAA-GFDL is licensed under a Creative Commons ...'
        mip_era                     'CMIP6'
        nominal_resolution          '100 km'
        original_name               'hurs'
        parent_activity_id          'CMIP'
        parent_experiment_id        'piControl'
        parent_mip_era              'CMIP6'
        parent_source_id            'GFDL-CM4'
        parent_time_units           'days since 1850-1-1 00:00:00'
        parent_variant_label        'r1i1p1f1'
        physics_index               1
        product                     'model-output'
        realization_index           1
        realm                       'atmos'
        references                  'see further_info_url attribute'
        source                      'GFDL-CM4 (2018): \naerosol: interactive\natmos: GFDL-AM4.0.1 (Cubed-sphere ...'
        source_file                 '/space/hall5/sitestore/eccc/crd/crd_shared/ESGF_downloads/CMIP6/CMIP/N ...'
        source_id                   'GFDL-CM4'
        source_type                 'AOGCM'
        sub_experiment              'none'
        sub_experiment_id           'none'
        table_id                    'day'
        title                       'NOAA GFDL GFDL-CM4 model output prepared for CMIP6 historical'
        variable_id                 'hurs'
        variant_info                'N/A'
        variant_label               'r1i1p1f1'
loaded from file /space/hall5/sitestore/eccc/crd/crd_shared/ESGF_downloads/CMIP6/CMIP/NOAA-GFDL/GFDL-CM4/historical/r1i1p1f1/day/hurs/gr1/v20180701/hurs_day_GFDL-CM4_historical_r1i1p1f1_gr1_19500101-19691231.nc
INFO    [1469952] 
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I created some fixes. Pull request to follow.

[valeriupredoi]

closed via #2294