The European Centre for Medium-Range Weather Forecasts (ECMWF) has produced ERA-40, a 45 year re-analysis covering the period September 1957 to August 2002. The ERA-40 data were produced at a resolution of T159/N80/L60 extending from the ground to 0.1hPa. The assimilation system uses 3D-VAR while the forecasting model is based on an operational model from around the year 2000. Additional documentation on ERA-40 can be found from the British Atmospheric Data Centre (BADC), and the ECMWF.

• The BADC's ERA-40 Live Access Server (LAS) allows sub-sets, plots and animations to be created dynamically from the ERA-40 dataset for registered users.
• A limited number of pressure level and surface fields are available on the ECMWF public data server.
• Six selections of monthly mean maps and cross sections from September 1957 to August 2002 are available at ECMWF.
• ERA-40 Project Report Series (pdfs)
• Model Documentation
• The web version of the ERA-40 Atlas is also available in hardcopy.

NCAS-Climate ERA-40 data

NCAS-Climate has extracted a subset of the ERA-40 data to produce a dataset that contains analyses on various level types, with some forecasts of surface fields. The data are archived at full resolution. Model level data are available to the NCAS community in GRIB format on HECToR, whilst other level types are available to local users in the Department of Meteorology, University of Reading in NetCDF format.

NCAS-Climate ERA-40 GRIB data

• These data are located on HECToR where they are available to NCAS users
• These data comprise six hourly data on model levels.
• ERA-40 GRIB data content and file naming conventions

NCAS-Climate ERA-40 NetCDF data

• These data are held on charney where they are available to local users in the Department of Meteorology, University of Reading
• These data comprise six hourly analyses at the surface and on pressure, isentropic and PV=2PVU levels.
• The (daily) forecast data is confined to a few fields at the surface.
• The GRIB data was converted to NetCDF using XCONV.
• In addition, monthly mean fields are being produced from the NetCDF data using the nco utilities.
• Monthly climatologies and interannual variability for the years 1957 to 2002 have been produced from the monthly mean data.
• ERA-40 NetCDF data content and file naming conventions
• ERA-40 NetCDF data: bugs and problems