1. Forecast system version
System name: CMCC-SPS3
First operational forecast run: 1st April, 2018
2. Configuration of the forecast model
Is it a coupled model? YES
Coupling frequency:
Atmosphere-Ocean: 90 minutes (every third timestep of atmospheric model)
Atmosphere-Land: 30 minutes (also timestep of atmospheric model)
Atmosphere-Sea Ice: 30 minutes (also timestep of atmospheric model)
2.1 Atmosphere and land surface
| Model | CAM 5.3 (Atmosphere) CLM 4.5 (land surface) |
|---|---|
| Horizontal resolution and grid | 1° lat-lon approx |
| Atmosphere vertical resolution | 46 vertical levels |
| Top of atmosphere | 0.2 hPa (60 km approx.) |
| Soil levels | 10 |
| Time step | 30 minutes |
Detailed documentation:
CAM Model documentation http://www.cesm.ucar.edu/models/cesm1.2/cam/
CLM Model documentation http://www.cesm.ucar.edu/models/cesm1.2/clm/
2.2 Ocean and cryosphere
| Ocean model | NEMO v3.4 |
|---|---|
| Horizontal resolution | 1/4° |
| Vertical resolution | 50 vertical levels |
| Time step | 18 minutes |
| Sea ice model | CICE 4.0 |
| Sea ice model resolution | 1/4° |
| Sea ice model levels | 1 thickness only |
| Wave model | NO |
| Wave model resolution | N/A |
Detailed documentation: goto NEMO documentation
3. Initialization and initial condition (IC) perturbations
3.1 Atmosphere and land
| Hindcast | Forecast | |
|---|---|---|
| Atmosphere initialization | ERA Interim | ECMWF IFS operational analysis |
| Atmosphere IC perturbations | 10 | 10 |
Land Initialization | Forced (obs. atmosphere) monthly run initialized from 10-year spin-up | Forced (obs. atmosphere) monthly run initialized from 10-year spin-up |
| Land IC perturbations | 3 | 3 |
| Soil moisture initialization | From land initialization | From land initialization |
| Snow initialization | From land initialization | From land initialization |
| Unperturbed control forecast? | NO | NO |
Detailed documentation:
For more DA details see ECMWF operational analysis documentation at: https://www.ecmwf.int/en/elibrary/16666-part-ii-data-assimilation
Data assimilation method for control analysis: ECMWF operational
Horizontal resolution of perturbation: N/A
Perturbations in +/- pairs: NO
3.2 Ocean and cryosphere
| Hindcast | Forecast | |
|---|---|---|
| Ocean initialization | C-GLORS Global Ocean 3D-VAR | C-GLORS Global Ocean 3D-VAR |
| Ocean IC perturbations | 4 | 8 |
| Unperturbed control forecast? | NO | NO |
Detailed documentation:
More ocean data assimilation details available at http://c-glors.cmcc.it/index/index.html
4. Model uncertainties perturbations:
| Model dynamics perturbations | NO |
|---|---|
| Model physics perturbations | NO |
If there is a control forecast, is it perturbed? | N/A |
Detailed documentation: N/A
5. Forecast system and hindcasts
| Forecast frequency | Monthly |
|---|---|
| Forecast ensemble size | 50 |
| Hindcast years | 1993-2016 |
| Hindcast ensemble size | 40 |
| On-the-fly or static hindcast set? | STATIC |
6. Other relevant information
The 10 atmospheric perturbed ICs, the 3 land perturbed ICs and the 8 (4 in hindcast mode) are combined to yield 240 (120 in hindcast mode) possible perturbed ICs among which the 50 ICs (40 in hindcast mode) to produce the forecast ensemble are chosen at random.
7. Where to find more information
Sanna, A., A. Borrelli, P. Athanasiadis, S. Materia, A. Storto, S. Tibaldi, S. Gualdi, 2017: CMCC-SPS3: CMCC-SPS3: The CMCC Seasonal Prediction System 3. Centro Euro-Mediterraneo sui Cambiamenti Climatici. CMCC Tech. Rep. RP0285, 61pp. Available at address:
https://www.cmcc.it/it/publications/rp0285-cmcc-sps3-the-cmcc-seasonal-prediction-system-3
