ECMWF Operational Analyses

The Operational data (1 March 1994 - present) consists of the ongoing analyses and forecasts produced by the most recent ECMWF Integrated Forecasting System (IFS) model. The IFS is regularly updated as improvements are made to the model, computing facilities and observations used in data assimilation (see the Changes to the ECMWF Operational Forecasting System page for more details).

The BADC stores data only at certain resolutions to complement data from ERA-15 and ERA-40, also available through the BADC.

The ECMWF datasets are for bona fide research purposes only and access is therefore restricted.

The BADC can only distribute the data to academic users within the UK on a per person per project basis (i.e. all members on a same project who will be using the data must individually apply for access to the data).

For this reason, we do not make the data available to anonymous users through these web pages. In order to gain access to the data and accompanying software, please apply for access to ECMWF Operational analysis data. The application form includes the Met Office agreement and ECMWF Operational analysis agreement. This will then be received by the BADC staff who will process your application usually within 1 working day of receipt. Providing your application has sufficient detail and that you meet the access requirements you will then be given access to the data via the Browse Archive pages of the BADC web-interface and from an account on the BADC computer (allowing FTP access to the data).

Note: German users may be able to access the data from the BADC under a reciprocal agreement with the Max-Planck Institute for Meteorology (MPI-M). German users will need to register with the MPI-M using this form which should be faxed to Model & Data, on +49-40-41173-400. Then apply for access through the BADC.

Under this reciprocal agreement, registered BADC users who are authorised to access the ECMWF Operational analysis data held at the BADC, may gain access to the ECMWF products held at MPI-M. Please contact data@dkrz.de for details.

Users from other countries may be able to access these data through their own national meteorological organisation.

Although the ECMWF calculate fields using a spectral model that is regularly updated in resolution the data available through the BADC are at T106 (N80) and T159 resolution for consistency with the ECMWF Reanalysis projects (ERA-15 and ERA-40) data and in order to reduce storage requirements. This dataset therefore complements and updates the ERA-15 and ERA-40 dataset, which are also available through the BADC.

The BADC archives the spectral T106 resolution from 1994 to 2000 on model levels with surface fields held on an N80 Gaussian grid.

From 2002 onwards, the data are available in the spectral T159 and N80 Reduced Gaussian grid resolution identical to the ERA-40 project.

T106 spectral form data are on model and pressure levels; T159 spectral form data are on model, pressure and theta levels; full and reduced Gaussian N80 grid data are avaiable on surface, model, pressure, theta and potential vorticity level for both analyses and forecasts.

Data are also available on two regular latitude-longitude grids. The 2.5° x 2.5° grid is stored on pressure levels from 1 March 1994 to present and the higher resolution 1.125° x 1.125° grid is stored on model levels from 1 January 2000 - present. The regular 2.5° x 2.5° gridded data also includes :

• surface monthly means and
• pressure level monthly means.

The parameters vary with the type of grid and level on which they are stored. The parameters page lists all the available variables for each grid type, level type and time period.

Please also read the ECMWF pages on Data deficiencies in the operational archive.

The BADC also holds Seasonal Forecasts (Hindcasts) on surface and pressure levels from 1987 to the present day and Monthly Means are available from 1994-present. These are available to all registered ECMWF Operational users.

A status page is maintained to document changes to the Operational archive.

By agreement with the ECMWF the BADC does not make Operational data available until 10 days after the forecast has been produced.

File Format

The datasets are held at the BADC in their original GRIB format.

GrADS/GRIB interface descriptor files (control file (*.ctl) and gribmap file (*.idx)) are also located in the archive for users who wish to download these alongside the GRIB data. (Note that these descriptor files may not be available for all the data in this dataset.)

The data can be accessed via FTP or via our web-interface.

The ECMWF now provides its own GRIB decoding software (GRIBEX) free from the ECMWF software pages. Documentation on other external software packages that can read GRIB.

Registered users can now access parts of this dataset via the BADC Data Extractor. See the Data Extractor web page for more details.

An ECMWF picture gallery is available to view some sample data.

Documentation

More details about the Operational data sets held at the BADC are available on the following topics:

• Grid resolution types (i.e. horizontal resolution).
• Level types (i.e. vertical resolution).
• Parameters.

Technical detail about level and grid types is also available via the ECMWF Technical site map.

The ECMWF web site provides detailed technical documentation about the Integrated Forecasting System (IFS) used to generate the data sets held at the BADC. The documentation is sub-divided into six sections accessible via the links below or as .pdf files (which require Adobe Acrobat Reader to view):

1. Observation processing    (or download .pdf version).
2. Data assimilation    (or download .pdf version).
3. Dynamics and numerical procedures    (or download .pdf version).
4. Physical processes    (or download .pdf version).
5. The Ensemble Prediction System    (or download .pdf version).
6. Technical and computational procedures    (or download .pdf version).

An ECMWF document entitled The description of the evolution of the ECMWF forecasting system and corresponding archive (published November 1999) is also available in .pdf format.

Deficiencies in the operational data are documented on the ECMWF web pages.

Links and References.

A set of links to ECMWF-related information on WWW, including the ECMWF home page is available from this page

The BADC holds other ECMWF datasets: ECMWF Re-Analyses (ERA-15 and ERA-40) and ECMWF trajectory data.

A list of references is also available.

European Centre for Medium-Range Weather Forecasts. ECMWF Operational Analysis data, [Internet]. NCAS British Atmospheric Data Centre. 2006-, Date of citation. Available from http://badc.nerc.ac.uk/view/badc.nerc.ac.uk__ATOM__dataent_ECMWF-OP.

If you would like to know more about ECMWF Operational data and how to obtain it from the BADC, you should contact us via the BADC support line. Your query should be answered within one working day. When follow-up work is required, the BADC support will carry out the work as quickly and efficiently as possible, and in any case, the user will be kept informed of progress.