| |
|---|---|
| System name (version) | ERA5 |
| Date of implementation | 2016 |
2. Configuration | |
|---|---|
Earth system components included in the analysis system (e.g., ocean, sea-ice, land, etc.) | |
Horizontal resolution of the model, with indication of grid spacing in km (for the different Earth system component included in the model) | TL639, 31 km atmosphere 0.36o ocean waves |
Number of levels in the different Earth system components (for the different Earth system component included in the model) | 137 levels in the atmosphere |
| Frequency of the outputs | 1-hourly |
| Analysis fields (such as MSLP and 2m temperature) | 00, 01 ... 23 UTC Daily means for analysis fields are computed from instantaneous values at 00, 01 ... 23 UTC. |
| Two-dimensional average diagnostic fields (such as total precipitation) | Average accumulations within a particular day=date are the average from the following forecasts:
|
| Top of the atmospheric model | 1 Pa |
| Number of analysis cycle per day | 2 |
| Earliest start date | 1 January 1940 |
| Integration time step | The model time step is 12 minutes for the HRES and 20 minutes for the EDA, though occasionally these numbers are adjusted to cope with instabilities |
| Length and frequency of the longest forecast | 18 hour forecasts initialised twice daily from analyses at 06 and 18 UTC |
| Dataset latency | ERA5T 5 days behind real time (preliminary product) ERA5 2–3 months (final product) |
Additional comments:
IFS cycle 41r2 used.
| 3. Analysis system | |
| Data assimilation method | 4D-Var |
| Length of the analysis window | 12 hours |
| Number of ensemble members and their resolution | 10, TL319, 63km |
Additional comments:
| 4. Externally prescribed boundary conditions and their source | |
| Sea surface temperature | January 1949–December 1960, HadISST2.1.0.0 (monthly), 0.25 x 0.25 January 1961–August 2007, HadISST2.1.1.0 (pentad), 0.25 x 0.25 September 2007 onwards, OSTIA, 0.05 x 0.05 |
| Sea-ice | January 1949–December 1960, HadISST2.0.0.0, 0.25 x 0.25 January 1961–December 1978, HadISST2.0.0.0, 0.25 x 0.25 January 1979–August 2007, OSI SAF (409a), 0.25 x 0.25 September 2007 onwards, OSI SAF oper 0.05 x 0.05 |
| Snow | in-situ, IMS 2004 onwards |
| Vegetation | prescribed non-time varying tiles, but using seasonally varying LAI |
| Land use (and its evolution in time) | prescribed non-time varying tiles |
| Aerosols | CMIP5 for volcanic and tropospheric sulphate; only seasonal variations for other species |
| Green House Gases | CMIP5 |
| Solar forcing | CMIP5, TIM scaling |
Additional comments:
| 5. Details of model | |
| Dynamical core (e.g., semi-Lagrangian) | semi-Lagrangian |
| Grid structure | TL639 |
| Hydrostatic or nonhydrostatic | Hydrostatic |
| Radiations parameterization | Chapter 2: https://www.ecmwf.int/en/elibrary/79697-ifs-documentation-cy41r2-part-iv-physical-processes |
| Boundary layer parameterization | Chapter 3: https://www.ecmwf.int/en/elibrary/79697-ifs-documentation-cy41r2-part-iv-physical-processes |
| Convection parameterization | Chapter 6: https://www.ecmwf.int/en/elibrary/79697-ifs-documentation-cy41r2-part-iv-physical-processes |
| Cloud parameterization | Chapter 7: https://www.ecmwf.int/en/elibrary/79697-ifs-documentation-cy41r2-part-iv-physical-processes |
| Land surface parameterization | Chapter 8: https://www.ecmwf.int/en/elibrary/79697-ifs-documentation-cy41r2-part-iv-physical-processes Land surface scheme: HTESSEL, Balsamo et al., 2009 |
Other relevant details:
Soil moisture DA: SEKF
Snow DA: 2D-OI
Radiative transfer model: RTTOVv11
Full details of cycle 41r2: Detailed information of implementation of IFS cycle 41r2
Detailed updated documentation on ERA5: ERA5: data documentation
| 6. Further information | |
| Operational contact point | Hans Hersbach, hans.hersbach@ecmwf.int |
| URL of the technical note/ reference paper | Hersbach et al. (2020) https://rmets.onlinelibrary.wiley.com/doi/full/10.1002/qj.3803 DOI: 10.1002/qj.3803 |
| URL for list of products | https://cds.climate.copernicus.eu/datasets?q=era5 |
| 7. Observational data used | |
| URL with the list of observational data used in the reanalysis | |
| DOI of data product if available |
Other sources for data access, if available