ERA-Interim production stopped on 31st August 2019
For the time being and until further notice, ERA-Interim (1st January 1979 to 31st August 2019) shall continue to be accessible through the ECMWF Web API. Keeping in mind that ERA-Interim is published with an offset of about three months from the dataset's reference date, ERA-Interim August 2019 data will be made available towards the end of October 2019.
ERA5 is now available from the Climate Data Store (CDS) (What are the changes from ERA-Interim to ERA5?) and users are strongly advised to migrate to ERA5 (How to migrate from ECMWF Web API to CDS API).
ERA-Interim and ERA-Interim/Land are two ECMWF Re-Analysis datasets. The main difference between ERA-interim and ERA-Interim/Land is the version of the TESSEL land-surface model (Tiled ECMWF Scheme for Surface Exchanges over Land).
ERA-Interim/Land is produced using the Hydrology-Tiled ECMWF Scheme for Surface Exchanges over Land (HTESSEL) model with meteorological forcing from ERA-Interim and precipitation adjustments based on GPCP v2.1 (dataset merges satellite and rain gauge (SG) data from a number of satellite sources). This scheme is an extension of the TESSEL scheme (van den Hurk et al., 2000) that was used in ERA-Interim, which was based on a 2006 version of ECMWF’s operational Integrated Forecasting System (IFS).
HTESSEL includes an improved soil hydrology (Balsamo et al., 2009), a new snow scheme (Dutra et al., 2010), a multi-year satellite-based vegetation climatology (Boussetta et al., 2011), and a revised bare-soil evaporation (Balsamo et al., 2011; Albergel et al., 2012a).
Both ERA/Interim and ERA-Interim/Land use four soil depth layers as follows:
| Level | Top (m) | Bottom (m) | Thickness (m) |
|---|---|---|---|
| 1 | 0.0 | 0.07 | 0.07 |
| 2 | 0.07 | 0.28 | 0.21 |
| 3 | 0.28 | 1 | 0.72 |
| 4 | 1 | 2.89 | 1.89 |
Soil moisture is available in both datasets with values typically between 0.1 and 0.4 in cubic meter water per cubic meter volume. ERA-Interim/Land should be preferred over ERA-Interim and make sure to select 'Analysis' when downloading the ERA-Interim/Land data.
For detailed documentation see Balsamo et al., 2012.
Reference
Albergel C., G. Balsamo, P. de Rosnay, J. Muñoz-Sabater and S. Boussetta, 2012a: A bare ground evaporation revision in the ECMWF land-surface scheme: evaluation of its impact using ground soil moisture and satellite microwave data, ECMWF Tech. Memo 685, 26pp., https://www.ecmwf.int/node/7671.
Balsamo, G., P. Viterbo, A. Beljaars, B. van den Hurk, M. Hirschi, A.K. Betts and K. Scipal, 2009: A revised hydrology for the ECMWF model: Verification from field site to terrestrial water storage and impact in the Integrated Forecast System, J. Hydrometeor., 10, 623–643, doi: 10.21957/yzyeh0vlw .
Balsamo, G., S. Boussetta, E. Dutra, A. Beljaars, P. Viterbo, and B. Van den Hurk, 2011: Evolution of land surface processes in the IFS, ECMWF Newsletter, 127, 17-22, doi: 10.21957/x1j3i7bz.
Balsamo and,Coauthors, 2012: ERA-Interim/Land: A global land-surface reanalysis based on ERA-Interim meteorological forcing. ECMWF ERA Report Series 13, 25 pp, https://www.ecmwf.int/node/7922
Boussetta, S., G. Balsamo, A. Beljaars and J. Jarlan, 2011: Impact of a satellite-derived Leaf AreaIndex monthly climatology in a global Numerical Weather Prediction model, ECMWF Tech. Memo. 640, 30 pp.,doi: 10.21957/h7n0ilfkp
Dutra, E., G. Balsamo, P. Viterbo, P. Miranda, A. Beljaars, C. Schär and K. Elder, 2010: An improved snow scheme for the ECMWF land surface model: description and offline validation, J. Hydrometeor., 11, 899-916, doi: 10.1175/2010JHM1249.1
van den Hurk, B., P. Viterbo, A. Beljaars and A.K. Betts, 2000: Offline validation of the ERA-40 surface scheme, ECMWF Tech. Memo. 295,44 pp., doi: 10.21957/9aoaspz8
