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 Interim is one of several products of two research projects, ERA-CLIM and ERA-CLIM2.

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.