The ECMWF ERA-15 Re-Analysis Project


The European Centre for Medium-Range Weather Forecasts (ECMWF) has provided global atmospheric analyses from its archive for many years. The ERA-15 Re-analysis project was devised in response to wishes expressed by many users for a data set generated by a modern, consistent, and invariant data assimilation system. A more detailed description of the ERA-15 project can be downloaded here in .pdf format.

Associated Organisations

ERA has received assistance from the ECMWF Council, the European Community, the University of California, the Japan Meteorological Agency (JMA), Cray Research Incorporated, and the Center for Ocean-Land-Atmosphere Studies (COLA). In addition, data and co-operation have been forthcoming from many quarters, including ECMWF Member States, the University of Innsbruck, the National Ocean and Atmospheric Administration (NOAA) and National Center for Atmospheric Research (NCAR) in the United States of America, and the Australian Bureau of Meteorology (BoM).

Data Sources

The ERA-15 Re-analysis project incorporated a number of observation sources. The real time World Meteorological Organisation (WMO) World Weather Watch data from the ECMWF archive (which had a 3 day cut-off) is augmented by the following additional data:

Sea surface temperature analyses for ERA-15 are provided by the United Kingdom Meteorological Office (UKMO) for the early period, and by NOAA from November 1981 onwards. Sea ice cover has been derived from SMMR and SSM/I satellite data. For a comprehensive report of the data sources used in the ERA-15 project you can download the ERA-15 Project Report.

The ERA-15 Data Assimilation System

The ERA-15 data assimilation system is a special version of the ECMWF Operational data assimilation system which incorporates:

For a more detailed description of the ERA-15 data assimilation system please see the ERA-15 Project Report.

The ECMWF Global Atmospheric Model

The ECMWF Global Atmospheric Model used to generate the ERA-15 dataset was consistent with the model used for Operational Analyses in the early 1990s. The ERA-15 model run was started in February 1993 and was completed in 1996.

For a more detailed description of the ERA-15 model please download the ERA-15 Project Report.

Validation and Evaluation of the ERA-15 dataset

Much research has been performed using the ERA-15 dataset including comparisons and evaluations of the product itself. For a detailed description of ERA-15 documented by the ECMWF see the ERA-15 Project Report Series.