ECMWF 15-year re-analysis data (ERA-15)

The European Centre for Medium-Range Weather Forecasts (ECMWF) has been using a model to produce forecast data since 1979. Due to improvements in model resolution and in the parameterisation of physical processes, the ECMWF model has been updated regularly over the years (see Changes to the Operational Forecasting System). While this improves the current ability of the model it means that model output from different time periods is not necessarily consistent.

The aim of the ECMWF Re-Analysis (ERA) project was to produce a long time-series of consistent meteorological analyses using a single version of the ECMWF model. The dataset spans the period 1 January 1979 - 28 February 1994. The BADC also archives ECMWF Operational analyses from 1 March 1994 - present.

The ECMWF used a spectral model to generate the ERA-15 dataset. The BADC archives the spectral T106 resolution data on model levels with surface fields held on an N80 Gaussian grid.

The data is also available on a 2.5° x 2.5° regular latitude-longitude grid. The upper air fields for the 2.5° x 2.5° gridded data is stored on pressure levels.

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.

A status page documents the changes to the ERA-15 archive.

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 ERA datasets. The application form includes the Met Office agreement and ECMWF ERA agreement, to be returned to the BADC.

You will then be given access to all ERA datasets held at the BADC 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 +49-40-41-17-34-00, before applying for access under this agreement through the BADC.

Under this reciprocal agreement, registered BADC users who are authorised to access the ERA 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.

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

The data stored in the BADC archives are in the GRIB 1 format.

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

When you register to use the ECMWF ERA-15 data we will tell you where to find the ECMWF documentation made available at the BADC. More details about the ERA-15 datasets 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.

Other useful documentation includes:

• The ERA-15 Project Report Series.
• ECMWF full description of the ERA-15 Re-analysis project (in .pdf format).
• Background to the ERA-15 project.
• References.

There is also documentation available via our ECMWF Operational data web pages detailing the Integrated Forecasting System that is used for operational forecasts. 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 ERA-15 data are documented on the ECMWF web pages.

See the ECMWF home page for further details about the ECMWF model products.

The BADC holds other ECMWF datasets: ECMWF Operational data, ECMWF ERA-40 Re-analyses and ECMWF ERA Interim data.

A list of references is also available.

European Centre for Medium-Range Weather Forecasts. ECMWF ERA-15 Re-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-ERA.

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.