ERA-Interim is a frequently used global atmospheric reanalysis produced by the European Center for Medium-Range Weather Forecasts (ECMWF). The ERA interim project was carried out to replace the previous atmospheric reanalyse ERA-40 in the long term. The data begin in 1979 and reanalysis is still ongoing. The forecasting model, data assimilation method and input data sets for ERA interim were described in the article mentioned in the references section below, where the performance of the system was discussed as well. In this re-analysis, several problems that were identified in ERA-40 were treated with improved methods, in particular the hydrological cycle, the quality of the stratospheric circulation and the temporal consistency of the analyzed fields. The number of atmospheric levels has been increased from 23 to 37 levels compared to ERA-40 and additional cloud parameters have been introduced. Please have a look at the mentioned licenses for information about usage restrictions.
Of the multitude of possible parameters and altitude levels, ICDC offers only a selection and only internally for registered users. The data has been obtained via the WDCC of the DKRZ. In the moment, data are offered from selected soil parameters, which can be understood as instantaneous values of the analysis step. The original data are available on the ECMWF site in GRIB format on a Gauss grid with the resolution N128. ICDC currently offers this data in NetCDF format on a regular Gaussian grid with a spatial resolution of about 0.7 ° and a temporal resolution of 6 hours for the period 1979 to 2018. Interpolation to a regular grid was abandoned to keep the data accuracy.
|Mean Sea Level Pressure||MSL||151||Pa|
|Sea ice cover /area fraction||CI||31||0-1|
|Temperature at 2m||2T||167||K|
|Total cloud cover||TCC||164||0-1|
|Total column water vapour||TCWV||137||kg/m2|
|U Wind component at 10m||10U||165||m/s|
|V Wind component at 10m||10V||166||m/s|
Period and temporal resolution:
- 1979-01-01 to 2018-31-12
Coverage and spatial resolution:
- Spatial resolution: approx. 0.7 ° x 0.7 °, latitude irregular (Gaussian grid)
- Geographic longitude: 0.0 ° E to 359.30 ° E
- Geographic latitude: -89.46 ° N to 89.46 ° N
- Dimension: 512 columns x 256 rows
- Altitudes: sfc
These are model data based on measured data. Possible sources of errors are faulty measured data that are assimilated into the model, as well as simplifications or even errors in the model. The quality of the data assimilation has been improved significantly compared to ERA40 and the model has a high quality. For details have a look on the project site at the ECMWF.
Name: Annika Jahnke-Bornemann
- Project description:https://www.ecmwf.int/en/forecasts/datasets/archive-datasets/reanalysis-datasets/era-interim
- Dee DP et. al., 2011: The ERA-Interim reanalysis: configuration and performance of the data assimilation system. Q. J. R. Meteorol. Soc. 137: 553–597. DOI:10.1002/qj.828, http://onlinelibrary.wiley.com/doi/10.1002/qj.828/abstract
- Berrisford, P., D. Dee, K. Fielding, M. Fuentes, P. Kallberg, S. Kobayashi and S. Uppala:The ERA-Interim archive, ERA Report Series, August 2009
- Jakobson et al., 2012: Validation of atmospheric reanalyses over the central Arctic Ocean. Geophys. Res. Lett., 39, L10802.
- Serreze et al., 2012: Recent changes in tropospheric water valor over the Arctic as assessed from radiosondes and atmospheric reanalyses. J. Geophys. Res., 117, D10104.
- Simmons A, Uppala S,Dee D,Kobayashi S. 2006. ERA-Interim: New ECMWF reanalysis products from 1989 onwards. ECMWF Newsletter 110: 26–35. DOI 10.21957/pocnex23c6