...
| Model | IFS Cycle 43r1 |
|---|---|
| Horizontal resolution and grid | Dynamics:TCO319 Cubic cubic octahedral grid Physics: O320 Gaussian grid (36 km) |
| Atmosphere vertical resolution | L91 (0.01 hPa) |
| Top of atmosphere | 0.01 hPa (approx. 80 km) |
| Soil levels | 4 |
| Time step | 20 minutes |
...
3. Initialization and initial condition (IC) perturbations
3.1 Atmosphere and land
| Re-forecastHindcast | Forecast | |
|---|---|---|
| Atmosphere initialization | ERA-Interim | ECMWF Operationsoperations |
| Atmosphere IC perturbations | Ensemble data assimilation and leading singular vectors applied to upper air variables | Ensemble data assimilation and leading singular vectors applied to upper air variables |
Land Initialization | ERA-Interim land (43r1) | ECMWF Operationsoperations |
| Land IC perturbations | Ensemble data assimilation applied to some land fields | Ensemble data assimilation applied to some land fields |
| Soil moisture initialization | ERA-Interim land | ECMWF operations |
| Snow initialization | ERA-Interim land | ECMWF operations |
| Unperturbed control forecast? | Yes | Yes |
Detailed documentation: IFS cycle 43r1 documentation and SEAS5 user guide
More DA details?
Data assimilation method for control analysis: 4D Var (atmosphere) and 3DVAR (ocean/sea-ice)
Horizontal and vertical resolution of perturbations: T42L91 SVs+ T399L137 EDA perturbations
Perturbations in +/- pairs: Yes
Detailed documentation: IFS cycle 43r1 documentation and SEAS5 user guide
3.2 Ocean and cryosphere
| Re-forecastHindcast | Forecast | |
|---|---|---|
| Ocean initialization | ORAS5 | ORTA5 |
| Ocean IC perturbations | Yes - generated through perturbations to assimilated observations and surface forcing | Yes - generated through perturbations to assimilated observations and surface forcing |
| Unperturbed control forecast? | No | No |
Detailed documentation: ECMWF ocean reanalysis documentation and SEAS5 user guide
Ocean data assimilation details? Source and treatment of SST? (Other data sources - altimetry?)
4. Model Uncertainties perturbations:
| Model dynamics perturbations | No |
|---|---|
| Model physics perturbations | 3- |
| level SPPT and SPBS | |
If there is a control forecast, is it perturbed? | Yes |
|---|
Detailed documentation: IFS cycle 43r1 documentation
5. Forecast system and
...
hindcasts
Note, the ECMWF seasonal forecasts cover two time ranges: the long range (LR) forecasts out to 7 months, and annual range (AR) forecasts out to 13 months, the latter not available from C3S. The model used for these forecasts is identical, but they have different numbers of forecast members.
| Forecast frequency | monthly (LR) quarterly (AR) |
|---|---|
| Forecast ensemble size | 51 (LR) 15 (AR) |
| Re-forecast Hindcast years | 36 (1981-2016) |
| Re-forecast Hindcast ensemble size | 25 (LR) 15 (AR) |
| On-the-fly or static re-forecast hindcast set? | static |
| Calibration (bias correction) period | 1993-2016 |
...