ERA-Interim reanalysis
Description
ERA-Interim is a climate reanalysis dataset, covering the period from 1979 to 31st August 2019. ERA stands for 'ECMWF Re-Analysis' and refers to a series of research projects at ECMWF which produced various datasets (ERA-Interim, ERA-40, etcetera).
ERA-Interim is now superseded by the ERA5 reanalysis.
ERA-Interim data is open access and free to download for all uses from the ECMWF data archive. Please see the guidelines on How to download ERA-Interim data from the ECMWF data archive.
ERA-Interim uses a fixed version of a numerical weather prediction (NWP) system (IFS - CY31r2) to produce reanalysed data. The fixed version ensures that no spurious trends are caused by an evolving NWP system, though the changing observing system can create such trends. The NWP system blends, or assimilates observations with a previous forecast to obtain the best fit to both. The result of this blending is called an analysis and is the starting point for the next forecast. In this manner, data is produced at increasingly later times.
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 00 UTC, 06 UTC, 12 UTC, 18 UTC
Please see the ERA-Interim documentation for full details (including list of parameters).
For further details please see:
Berrisford, P., P. Kållberg, S. Kobayashi, D. Dee, S. Uppala, A. J. Simmons, P. Poli, and H. Sato, 2011: Atmospheric conservation properties in ERA-Interim. Q.J.R. Meteorol. Soc., 137: 1381–1399. doi: 10.1002/qj.864
Local host (English)
Available at NCI at:
- /g/data/ub4/erai/. for 3hr and 6hr data
- /g/data/ua8/synda/CREATE-IP/reanalysis/ECMWF/IFS-Cy31r2/ERA-Interim/atmos/mon/v20200608 for monthly data
The 3hr and 6hr data can also be accessed via this intake catalogue:
Access information (English)
Preferred citation:
European Centre for Medium-range Weather Forecast (ECMWF) (2011): The ERA-Interim reanalysis dataset, Copernicus Climate Change Service (C3S) (accessed <insert date of access here>), available from https://www.ecmwf.int/en/forecasts/datasets/archive-datasets/reanalysis-datasets/era-interim
Please also add the following paper to the references:
https://rmets.onlinelibrary.wiley.com/doi/abs/10.1002/qj.828
Additional details
- From date
-
1979-01-01
- To date
-
2019-08-31
- Geospatial resolution
- >50 & <=100 km or approx. 0.5-1 deg
- Frequency
- 6-Hourly, 3-Hourly, Monthly
- Region
- Global
- Variables realm
- Land Surface, Atmosphere, Sea ice, Ocean
- Files format
- netcdf