Test data is available from 1 November 2020 onwards from the MARS archive, but only data since 5 January 2021 is based on the final configuration. A daily updated test dataset is also available for the most recent 3 days on the FTP server. 


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


WebAPI service

If you don't have access to ECMWF computers but would still like to access a large subset of test data you can use ECMWF WebAPI service.

Read documentation and see brief request syntax of the ECMWF WebAPI service.

If you haven't done it yet you will need to create an ECMWF web account and accept the data licence.


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

#!/usr/bin/env python
from ecmwfapi import ECMWFDataServer
server = ECMWFDataServer()

    "dataset":   "cams_esuite",
    "stream":    "oper",
    "type":      "fc",
    "date":      "20210201/to/20210210",
    "time":      "00",    
    "step":      "0/to/23/by/1",
    "levtype":   "sfc",
    "format":    "netcdf",
    "param" :    "aod550",         # see parameter table at http://atmosphere.copernicus.eu/ftp-access-global-data
    "grid":      "0.4/0.4",        # 0.4 x 0.4 regular lat-lon grid
    "area":      "70/-35/35/60",   # N/E/S/W area boundaries
    "target":    "/tmp/cams_test_202102.nc"

FTP dissemination

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


You can use your normal FTP account to access the data.

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