The ECMWF FTP service provides access to real-time data from the CAMS global atmospheric composition system. For product documentation please see here. For a description of the current global model please see here (including information on system upgrades) . For other data access options please see here.

Please see the list of available atmospheric composition variables below and make sure your variables of interest are available. Please contact us if you require any additional species.

User accounts

To get access to CAMS global data, you need user accounts on the ECMWF website, and on the ECMWF FTP service.

  1. Log on to (If you do not have an account create one)
  2. Read the CAMS data licence and accept the license at the bottom of the page.
  3. Send an email to, providing 
    1. the user name you used to log into and accept the license
    2. for our service planning, a brief description of how you intend to use the data, and which chemical species are most relevant for you

Data location

FTP server

Data directory


Retention policy

Forecast are kept for 3 days

File naming convention

The file naming convention is based on WMO guidelines as follows:



ecmf is the WMO location indicators. The list can be found here.
yyyymmddhhmmss is the base date and time of the forecast.
vvvv is a version or experiment identifier. prod will be used for operational products, test (or experiment ID) will be used for testing purposes, rean for reanalysis if needed.
tt type of data, fc - forecast, an - analysis
lt is the type of level. pl for pressure level products, sfc for surface fields, ml for model level fields

 is the forecast hour time step. For accumulation and averages, it is the

end time. This number must be zero padded to 3 digits, e.g. step 24 is given as 024


 is the parameter short name as defined here

grib, nc

 is the format of a file, GRIB or NETCDF

Data organisation

The dataset is grouped by type of product (analysis or forecast), level type (surface parameter, pressure level or model level), by step or forecast range and by parameter. 


z_cams_c_ecmf_20160704000000_prod_an_sfc_000_tchcho.grib  contains analysis field of total column formaldehyde computed on 7 July 2016 at 00:00 UTC.

z_cams_c_ ecmf_20160704000000_prod_fc_pl_012_co.grib contains all the pressure levels of +12 step CO fields from a forecast started on 7 July 2016 at 00:00 UTC.

z_cams_c_  contains all the model levels of step 12 O3 fields from a forecast which was started on 7 July 2016 at 12:00 UTC in NetCDF format.

Data availability

The latest model cycle based on the 00 UTC analysis is normally available by 10:00 UTC, the cycle based on 12 UTC analysis is available by 22:00 UTC.

After the data transfer to the ftp server is completed a manifest file is uploaded:


The file is uploaded to the server only after all the data files have been successfully uploaded. The file contains a list of all the GRIB and NetCDF files in the cycle and their MD5 checksums in case you would like to verify data integrity.

List of available parameters

Data volumes per model cycle

The data volumes are based on the current CAMS experiment (link).


file size (GRIB / NC)

No. of fields
per file

No. of variables

No. of files (GRIB or NC)

Total size (GRIB)

Total size (NC)

an_sfc1.2 MB / 800 kB1151518 MB12 MB


30 MB / 20 MB251624697 MB465 MB
an_ml70 MB / 47 MB6016251,7 GB1,1 GB
fc_sfc1.2 MB / 800 kB12633883,9 GB2,6 GB
fc_pl30 MB / 20 MB252498428 GB19 GB
fc_ml70 MB / 47 MB6025102568 GB45 GB
  Total 5461102 GB68 GB

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