Current availability of ERA-40 analyses.

News

7th ofJuly 2003 Selected fields from ERA40 can now be downloaded directly from our website. Read on >>

3rd ofJuly 2003 The migration of the different ERA40 experiments to EXPVER=1 is now complete for all but some special fields. We encourage all users to retrieve the data from EXPVER=1, since this makes better use of the resources and speeds up the retrievals.

The production of the ERA-40 analyses is now complete. The final version of the reanalysis products (class=e4 and expver=1) have been created from the three main assimilation streams (0020, 0030 and 0018), the extra assimilation streams and the shorter rerun assimilations necessary due to technical problems or problems with satellite radiance tuning. The set of experiment identifiers and periods from which the final version is being constructed are given below. These are consistent with earlier advice on data availability. Users will be informed when the final version has been completed, which is estimated to take two to three months. The expver=1 version will then constitute the official ERA-40 Archive including also the observations (type=ai) and the corresponding feedback information.

19570901 - 19571130 EXPVER=0272

19571201 - 19720430 EXPVER=0020

19720501 - 19721231 EXPVER=0334

19730101 - 19740430 EXPVER=0030

19740501 - 19740630 EXPVER=0335

19740701 - 19850331 EXPVER=0030

19850401 - 19860331 EXPVER=0050

19860401 - 19881031 EXPVER=0040

19881101 - 19881231 EXPVER=0338

19890101 - 19941231 EXPVER=0018

19950101 - 19950430 EXPVER=0274

19950501 - 20020831 EXPVER=0018

Recent evaluations within the project confirm that the quality of the products is generally high and in some cases above expectations. There are however periods during which some products should be used with caution. These will soon be documented and the quality statement updated accordingly on the web.

There are plans to do a new reanalysis for the latter part of the ERA-40 period (possibly from 1979 or 1987 onwards), but this will not be started until sufficient progress has been made in addressing certain problem areas.

The analyses are available to all users with direct access to MARS, ECMWF's Meteorological Archival and retrieval System.

ERA-40 analyses for the years listed are also available for supply to general users by ECMWF Data Services. Arrangements exist within some ECMWF Member States for national supply of data, to facilitate access in particular to those users unable to obtain data directly from MARS. In addition, NCAR, a partner in the ERA-40 project, may distribute data to UCAR members and to non-UCAR research and educational institutions in the USA for scientific, research and educational uses. The data available from these national sources may be less complete than that available from ECMWF. ECMWF has made plans for the production and supply of subsets of the data through CD-ROMs and the Internet, but such products are not yet available.

Monthly means

Monthly mean analyses and short-range forecasts from Streams 1, 2 and 3 are now also available; from MARS for direct access users and from ECMWF Data Services for all other users.

The monthly means are described in the archive plan. The monthly fluxes described there are not yet available from MARS. For MARS access to the monthly means the following request parameters should be used:

DATE=YYYYMM00, N.B.! The day should be 00
STREAM=mnth for monthly synoptic means
STREAM=moda for monthly diurnal means
TIME=0000/0600/1200/1800 for STREAM=mnth
TIME=0000 for STREAM=moda