1. Forecast system version
System name: CMCC-SPS3.5
First operational forecast run: 1st October, 2020
2. Configuration of the forecast model
Is it a coupled model? YES
Coupling frequency:
Atmosphere-Ocean: 90 minutes (every third full-timestep of atmospheric model)
Atmosphere-Land: 30 minutes (also full-timestep of atmospheric model)
Atmosphere-Sea Ice: 30 minutes (also full-timestep of atmospheric model)
Detailed documentation:
CMCC technical documentation Gualdi et al (2020) CMCC Technical Note RP0288 https://www.cmcc.it/publications-type/technical-notes?f_anni&filter_topics&f_divisioni=747&f_inpress&f_searchkey
2.1 Atmosphere and land surface
| Model | CAM 5.3 (Atmosphere) CLM 4.5 (land surface) |
|---|---|
| Horizontal resolution and grid | 1/2° lat-lon approx |
| Atmosphere vertical resolution | 46 vertical levels |
| Top of atmosphere | 0.2 hPa (60 km approx.) |
| Soil levels | 10 |
| Time step | Main (Physics) Time-step: 30 minutes. “Tracer” Advection Time step: 225 seconds (1/8 of the Physics time step) Fluid-Dynamics Time step: 56.25 seconds (1/32 of the Physics time step). |
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/
CMCC technical documentation Gualdi et al (2020) CMCC Technical Note RP0288 https://www.cmcc.it/publications-type/technical-notes?f_anni&filter_topics&f_divisioni=747&f_inpress&f_searchkey
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:
Nemo Model documentation https://www.nemo-ocean.eu/doc/
CMCC technical documentation Gualdi et al (2020) CMCC Technical Note RP0288 https://www.cmcc.it/publications-type/technical-notes?f_anni&filter_topics&f_divisioni=747&f_inpress&f_searchkey
3. Initialization and initial condition (IC) perturbations
3.1 Atmosphere and land
| Hindcast | Forecast | |
|---|---|---|
| Atmosphere initialization | ERA5 | 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 |
| Horizontal resolution of perturbation | N/A | N/A |
| Perturbations in +/- pairs | NO | NO |
| Data assimilation method for control analysis | ERA5 | ECMWF operational |
Detailed documentation:
For more atmospheric DA details, see ECMWF operational analysis documentation at: https://www.ecmwf.int/en/elibrary/16666-part-ii-data-assimilation
For more ERA5 details: https://doi.org/10.1002/qj.3803.
CMCC technical documentation Gualdi et al (2020) CMCC Technical Note RP0288 https://www.cmcc.it/publications-type/technical-notes?f_anni&filter_topics&f_divisioni=747&f_inpress&f_searchkey
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 | YES (Ocean Model only, only during perturbed data assimilation cycles) |
If there is a control forecast, is it perturbed? | There is no Control Forecast |
Detailed documentation: For more info on Ocean D/A perturbations, see Brankart (2013) DOI: https://doi.org/10.1016/j.ocemod.2013.02.004
CMCC technical documentation Gualdi et al (2020) CMCC Technical Note RP0288 https://www.cmcc.it/publications-type/technical-notes?f_anni&filter_topics&f_divisioni=747&f_inpress&f_searchkey
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.
Detailed documentation:
CMCC technical documentation Gualdi et al (2020) CMCC Technical Note RP0288 https://www.cmcc.it/publications-type/technical-notes?f_anni&filter_topics&f_divisioni=747&f_inpress&f_searchkey
7. Where to find more information
Sanna, A., A. Borrelli, P. Athanasiadis, S. Materia, A. Storto, S. Tibaldi, S. Gualdi, 2017: CMCC-SPS3: The CMCC Seasonal Prediction System 3. Centro Euro-Mediterraneo sui Cambiamenti Climatici. CMCC Tech. Note RP0285, 61pp. https://www.cmcc.it/publications-type/technical-notes?f_anni&filter_topics&f_divisioni=747&f_inpress&f_searchkey
Gualdi, S., A. Sanna, A. Borrelli, A. Cantelli, M. del Mar Chaves Montero, S. Tibaldi, 2020: The new CMCC Operational Seasonal Prediction System SPS3.5. Centro Euro-Mediterraneo sui Cambiamenti Climatici. CMCC Tech. Note RP0288, 26pp. https://www.cmcc.it/publications-type/technical-notes?f_anni&filter_topics&f_divisioni=747&f_inpress&f_searchkey
