1. Forecast system version
System name: Météo-France System 6
First operational forecast run: March 2017 (First used in C3S products in November 2018)
2. Configuration of the forecast model
Is it a coupled model? yes
Coupling frequency: 3 hours
2.1 Atmosphere and land surface
| Model | ARPEGE v6.2 SURFEX v8.1 |
|---|---|
| Horizontal resolution and grid | TL359; 0.5° reduced Gauss grid |
| Atmosphere vertical resolution | 91 layers |
| Top of atmosphere | top layer above 0.2 Pa |
| Soil levels | 14 layers |
| Time step | 7.5 min |
Detailed documentation:
ARPEGE http://www.umr-cnrm.fr/IMG/pdf/arp62ca.july2017.pdf
Soil model (SURFEX) http://www.umr-cnrm.fr/surfex//IMG/pdf/surfex_scidoc_v8.1.pdf
2.2 Ocean and cryosphere
| Ocean model | NEMO v3.4 |
|---|---|
| Horizontal resolution | 1° ORCA grid |
| Vertical resolution | 75 levels |
| Time step | 30 min |
| Sea ice model | GELATO v6 |
| Sea ice model resolution | 1° ORCA grid |
| Sea ice model levels | 9 (+1 for snow) |
| Wave model | None |
| Wave model resolution | NA |
Detailed documentation: NEMO documentation
3. Initialization and initial condition (IC) perturbations
3.1 Atmosphere and land
| Hindcast | Forecast | |
|---|---|---|
| Atmosphere initialization | ERA-interim | IFS |
| Atmosphere IC perturbations | none | none |
Land Initialization | ERA-interim | IFS |
| Land IC perturbations | none | none |
| Soil moisture initialization | ERA-interim | IFS |
| Snow initialization | ERA-interim | IFS |
| Unperturbed control forecast? | NA | NA |
Detailed documentation: see ECMWF page
3.2 Ocean and cryosphere
| Hindcast | Forecast | |
|---|---|---|
| Ocean initialization | GLORYS2V2 | Mercator-Ocean |
| Ocean IC perturbations | None | None |
| Unperturbed control forecast? | NA | NA |
Detailed documentation: http://www.mercator-ocean.fr/science/GLORYS
4. Model uncertainties perturbations:
| Model dynamics perturbations | Yes |
|---|---|
| Model physics perturbations | No |
If there is a control forecast, is it perturbed? | NA |
Detailed documentation:Batté, L. and Déqué, M., 2016: Randomly correcting model errors in the ARPEGE-Climate v6. 1 component of CNRM-CM: applications for seasonal forecasts, Geoscientific Model Development,9, 2055-2076, doi:10.5194/gmd-9-2055-2016
5. Forecast system and hindcasts
| Forecast frequency | month |
|---|---|
| Forecast ensemble size | 51 |
| Hindcast years | 1993-2016 |
| Hindcast ensemble size | 25 |
| On-the-fly or static hindcast set? | static |
6. Other relevant information
The hindcast/forecast ocean initial conditions are calculated with Mercator-Ocean PSI2G4R1 software..
The forecast uses three start dates:
- The 20th of the previous month (25 members in the forecasts, 12 members in the hindcasts)
- The 25th of the previous month (25 members in the forecasts, 12 members in the hindcasts)
- the 1st of the month (1 member in the forecast/hindcast)
7. Where to find more information
Technical implementation details can be found in http://www.umr-cnrm.fr/IMG/pdf/system6-technical.pdf
