The dataset is covering the period from 1 June 2017 until present.


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":      "20170701/to/20170710",
    "time":      "00",    
    "step":      "0/to/23/by/1",
    "levtype":   "sfc",
    "format":    "netcdf",
    "param" :    "aod550",         # see parameter table at
    "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/"


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. The list of parameters is the same as in the current data streams.

If everything else fails ...

... you can always contact us by using this contact form 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