ERA-Interim is a dataset, showing the results of a global climate reanalysis from 1979 to date. ERA-Interim continues to be updated in near-real-time as new data becomes available.

ERA stands for 'European Reanalysis' and refers to a series of research projects at ECMWF which produced various datasets (ERA-Interim, ERA-40, etcetera).

Product description

•  The ERA-Interim dataset contains atmospheric and surface parameters:
  • 6-hourly atmospheric fields on model levels, pressure levels, potential temperature and potential vorticity
  • 3-hourly surface fields and daily vertical integrals
  • Monthly averages of daily means

  • Synoptic monthly averages at 0 UTC, 6 UTC, 12 UTC, 18 UTC

• The temporal coverage is from 1 January 1979 to present
• The spatial coverage is global
• The spectral resolution is T255 (~80 km spatial resolution) on 60 vertical levels from the surface up to 0.1 hPa.

• The data assimilation system used to produce ERA-Interim is based on a 2006 release of the Integrated Forecast System (IFS - Cy31r2). The system includes a 4-dimensional variational analysis (4D-Var) with a 12-hour analysis window.

Parameters and download

For a list of fields (parameters) in ERA-Interim and for downloading data see the ECMWF dataserver. Note that while ERA-Interim "runs" in near real time, data is published with a few moths delay.

Note that we are aware of several quality issues with ERA-Interim data.

Further documentation

See Berrisford et al. (2011) for detailed documentation of the parameters in this dataset.

An open-access journal article describing the ERA-Interim reanalysis is available from the Quarterly Journal of the Royal Meteorological Society. Additional details of the modelling and data assimilation system used to produce ERA-Interim can be found in the IFS documentation (choose Cy31r1) .

Further detailed documentation on ERA-Interim is available in the ECMWF eLibrary.