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.