CAMS global forecast test data is available from 1 September 2022 onwards from the MARS archive. A daily updated test dataset is also available for the most recent 3 days on the FTP server.

Because of GFAS hourly plume model component will be updated together with CAMS global forecast, GFAS hourly test data is available as well, from 1 December 2018 onwards from MARS archive and an hourly updated test data made available on the FTP server.

MARS

If you have access to ECMWF systems you can retrieve CAMS global forecast test data from MARS archive using keywords:

class=mc
expver=0078

GFAS hourly test data can be retrieved as well, using keywords:

class=mc
expver=9911

You can use this link to directly access the data in the MARS catalogue (please remember that ecCodes version 2.28.0 or later is required to handle the full range of parameters of current CAMS data).

Atmosphere Data Store (ADS)

If you don't have access to ECMWF computers but would still like to access a large subset of test data, you can retrieve fields of the cams-global-atmospheric-composition-forecasts-test dataset using the Copernicus Atmosphere Data Store API.

If you haven't done it yet you will need to create an account and accept the terms of use of Copernicus Atmosphere Data Store.

Example

Total aerosol optical depth at 550 nm in NetCDF format, only European domain, 10 dates, day 1 forecast

import cdsapi

c = cdsapi.Client()

c.retrieve(
    'cams-global-atmospheric-composition-forecasts-test',
    {
        'date':          '2023-03-01/2023-03-10',
        'type':          'forecast',
        'format':        'netcdf_zip',
        'variable':      'total_aerosol_optical_depth_550nm', # See available 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(0,24)],
        'area':          [70, -35, 35, 60],                   # [N,E,S,W] area boundaries
    },
    '/tmp/cams_test_20230301_10.nc.zip')

FTP dissemination

The test dataset is available through ECPDS FTP dissemination systems in these directories:

/DATA/CAMS_GLOBAL_TEST
/DATA/CAMS_GLOBAL_ADDITIONAL_TEST
/DATA/CAMS_EUROPE_BC_TEST
/DATA/CAMS_GFAS_HOURLY_TEST

You can use your normal FTP account to access the data. Details about filenames convention or list of available parameters can be found at Copernicus Knowledge Base.

If everything else fails ...

... you can always contact us by sending an email to copernicus-support@ecmwf.int putting "Request for CAMS global test dataset" as a subject and specify:

• which parameters and levels
• which time period
• forecast step / time frequency
• which geographical area
• which data format you require