import cdsapi

c = cdsapi.Client()

c.retrieve(
    'cams-global-atmospheric-composition-forecasts-test',
    {
        'date':          '2023-04-01/2023-04-10',
        'type':          'forecast',
        'format':        'netcdf_zip',
        'model_level':   '137',                    # GetLowest lowest model level only
        'variable':    [ 'biogenic_secondary_organic_aerosol_mass_mixing_ratio',
                         'anthropogenic_secondary_organic_aerosol_mass_mixing_ratio',
                         'glyoxal' ],      # See other variables at:
        'time':          '00:00',          # https://ads.atmosphere.copernicus.eu/cdsapp#!/dataset/cams-global-atmospheric-composition-forecasts?tab=form
        'leadtime_hour': [h for h in range(0,25,3)],
        'area':          [70, -35, 35, 60] # [N,E,S,W] Europe area boundaries
    },
    '/tmp/cams_test_20230401_10_ml.nc.zip')

c.retrieve(
    'cams-global-atmospheric-composition-forecasts-test'secondary_organic_aerosol_optical_depth_550nm',
    {
        'date':          '2023-04-01/2023-04-10',
        'type':          'forecast',
        'format':        'netcdf_zip','total_column_glyoxal' ], # See other variables at:
        'variabletime':    [ 'secondary_organic_aerosol_optical_depth_550nm', # These variables only exist at surface
                         'total_column_glyoxal' ]'00:00',  
        'time':        #  '00:00',https://ads.atmosphere.copernicus.eu/cdsapp#!/dataset/cams-global-atmospheric-composition-forecasts?tab=form
        'leadtime_hour': [h for h in range(0,25,3)],
        'area':          [70, -35, 35, 60]         # [N,W,S,E] Europe area boundaries
    },
    '/tmp/cams_test_20230401_10_sfc.nc.zip')