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Status of the ERA-40 Re-Analysis Archive at the BADC

This page is updated monthly to inform users of the current status of ERA-40 at the BADC.


The BADC is extracting ECMWF ERA-40 Re-analysis data on a daily basis to keep pace (with a slight delay) with production. The data is currently being copied into two separate archives:

The reason for holding two separate data archives is to meet the requirements of two distinct groups of atmospheric (and other) scientists. The standard BADC archive will serve the data using formats and utilities that the majority of earth scientists can make use of. The Manchester archive, on the other hand, is aimed specifically at users of the modelling resources held on the high-performance computing systems. This data will be mainly used by members of UGAMP (the UK universities Global Atmospheric Modelling Programme). This page gives an overview of the contents and the current status of each archive.

Links are also provided to validation information relating to ERA-40 and a latest news page for ERA-40.

Production Status

The ECMWF is running the ERA-40 model in four parallel streams: Stream 1 (1987-2001), Stream 2 (1957-1972), Stream 3 (1972-1985) and Stream 4 (1985-1988). The speed at which the BADC can populate our archive with ERA-40 data depends on the production rate at the ECMWF. Table 1 shows the production status information and Table 2 shows which years have been processed and validated for each stream.

Table 1.   Production status for ERA-40 data.
Production Status Information
StreamStream 1Stream 2Stream 3Stream 4
Start Year1987195719721985
End Year2001197219851988
Production startedMid-2001Mid-2001Mid-2001Nov-2002
Production due to end (estimate)Mar-03Apr-03Apr-03Mar-03
Average speed [wall time hours/assimilated month]150.3101.8105.8104.5
Speed of last 30 days [wall time hours]89626680

Table 2.   Years produced and validated so far for ERA-40.
Full Years Produced (and Validated) So Far
Stream 1Stream 2Stream 3Stream 4
* P - Produced: the data has been produced for that year but has NOT been validated. If errors have been identified then some years will be re-run later.
** P+V - Produced and validated: the data has been produced and has been successfully validated.

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The standard BADC ERA-40 Archive

The standard BADC archive (at the Rutherford Appleton Laboratory) is only currently only extracting ERA-40 data that has been validated. The data currently held in the BADC archive is shown in Table 3. This data is being archived to a tape library initially but is all being gradually migrated to disk. Development of a software tools to allow users to extract subsets of the data and create visualisations is planned over the next two years. If you have registered as an ERA-40 user and you wish to obtain data from the standard BADC archive please contact BADC Support.

Table 3.   ERA-40 data currently in the standard BADC archive.
Validated ERA-40 data at the BADC
Stream 1Stream 2Stream 3Stream 4
1987All year1957-1972All year1985All year
1988All year1958All year1973All year1986All year
1989All year1959All year1974All year1987All year
1990All year1960All year1975All year1988All yeara
1991All year1961All year1976All year
1992All year1962All year1977All year
1993All year1963All year1978All year
1994All year1964All yeaa1979All year
1995All year1965All year1980All year
1996All year1966All year1981All year
1997All year1967All year1982All year
1998All year1968All year1983All year
1999All year1969All year1984All year
2000All year1970All year1985All year
2001All year1971All year
1972All year

The data in the standard archive is being held in its original GRIB format in T159 Spectral and N80 Reduced Gaussian Gridded resolutions.

The BADC is developing a new system that will allow users to access the ERA-40 dataset in a regular gridded format. This will probably involve the conversion of spectral and reduced Gaussian gridded data when the user calls the files. The main reason for storing all the data in the spectral and reduced Gaussian forms is that these formats are considerably smaller in volume than the equivalent 1° x 1° gridded data. This allows us to hold all the data on disk.

ERA-40 data is held on the following atmospheric level types:

Details about the variables available in the BADC archive are documented on the ERA-40 parameters page. Each individual file holds one parameter at one time-step for the entire globe. A common file-naming convention has been adopted for both ERA-40 archives.

The data can be accessed using an account on Tornado, the BADC's UNIX machine, or via our web-interface.

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The Manchester BADC ERA-40 Archive

The Manchester BADC ERA-40 archive is populated and managed by Paul Berrisford of CGAM at the University of Reading. Documentation about the archive is available from the CGAM web site. The data is being stored in both GRIB and NetCDF formats on the 128-processor Origin 2000 machine, Fermat. The files on Fermat are instantaneous but contain several fields (e.g. in the GRIB files all pressure level spectral fields are together, and in NetCDF files all pressure level fields are together). The parameters stored at Manchester are the same as those held in the standard BADC archive. Files of one type, at one analysis time, are tarred together for each available month. For example, all the 06:00 hour files are tarred into one file for January (as opposed to the standard BADC archive where each time-step has a separate file). A common file-naming convention has been adopted for both ERA-40 archives.

Queries about the accessing the Manchester dataset and its contents should be directed to Paul Berrisford. Please note that you will need to register as a BADC user for ERA-40 data if you want to gain access to either of the archives.

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Links Relating to the Validation of ERA-40 data

The ECMWF web pages document data quality issues relating to ERA-40. This includes information on a probable rerun of the latter part of ERA-40.

You can also visit the links below to access details of validation studies for ERA-40:

Recent information about the ERA-40 data and archive is available on the a latest news page.

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