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Draft document. It needs to be reviewed (by MetOffice, Craig MacLachlan). I have just updated some details (name, first operational date) but the main of the changes needs to be done (I guess, table 3.1 essentially) Please review it carefully to fill in all the relevant details Page restrictions need to be disabled (so it becomes a public page) Simona Briceag when Craig has finished reviewing. The parent page would also need to be edited to add the link to this page This Warning needs to be removed |
1. Forecast system version
System name: GloSea5-GC2-LI
First operational forecast run: 2 April 2019
2. Configuration of the forecast model
Is it a coupled model ? Yes: Atmosphere, land, ocean and sea-ice.
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The coupled model Global Coupled 2 (GC2) is described in Williams et al, 2015.
2.1 Atmosphere and land surface
| Model | Met Office Unified Model (UM) - Global Atmosphere 6.0 Joint UK Land Environment Simulator (JULES) - Global Land 6.0 |
|---|---|
| Horizontal resolution and grid | N216: 0.83 degrees x 0.56 degrees (approx 60km in mid-latitudes) |
| Atmosphere vertical resolution | 85 levels |
| Top of atmosphere | 85km |
| Soil levels | 4 Level 1 : 0 - 0.1 m Level 2 : 0.1 - 0.35 Level 3 : 0.35 - 1.0 m Level 4 : 1.0 - 3.0 m |
| Time step | 15 minutes |
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Global Atmosphere 6.0 & Global Land 6.0: Walters et al, 2017
2.2 Ocean and cryosphere
| Ocean model | NEMO v3.4 - Global Ocean 5.0 |
|---|---|
| Horizontal resolution | ORCA 0.25 |
| Vertical resolution | L75 |
| Time step | 22.5 minutes |
| Sea ice model | CICE v4.1 - Global Sea-Ice 6.0 |
| Sea ice model resolution | ORCA 0.25 |
| Sea ice model levels | 5 categories + open water |
| Wave model | N/A |
| Wave model resolution | N/A |
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Global Sea Ice 6.0: Rae et al, 2015.
3. Initialization and initial condition (IC) perturbations
3.1 Atmosphere and land
| Hindcast | Forecast | ||||
|---|---|---|---|---|---|
| Atmosphere initialization | ERA-Interim | Met Office Global Hybrid 4D-VAR | |||
| Atmosphere IC perturbations | None | None | Land InitializationClimatology/ERA-Interim | Climatology/Met Office Global Hybrid 4D-VAR | |
| Land IC perturbations | None | None | |||
| Soil moisture & temperature initialization | Met Office JULES-JRA55 analysis | Met Office JULES-JRA55 analysis | |||
| Snow initialization | Met Office JULES-JRA55 analysis | Met Office JULES-JRA55 analysis | |||
| Unperturbed control forecast? | No | No |
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Met Office Global Hybrid 4D-VAR: Clayton et al, 2013
3.2 Ocean and cryosphere
| Hindcast | Forecast | |
|---|---|---|
| Ocean initialization | GloSea Ocean Sea-Ice Analysis (GS-OSIA) | Forecast Ocean Assimilation Model (FOAM) |
| Ocean IC perturbations | No | No |
| Unperturbed control forecast? | No | No |
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The common NEMOVAR system is described in Blockley et al, 2014 . Details of the GS-OSIA can be found in MacLachlan et al, 2015 .
4. Model uncertainties perturbations:
| Model dynamics perturbations | None |
|---|---|
| Model physics perturbations | Atmosphere stochastic physics scheme, SKEB2 |
If there is a control forecast, is it perturbed? | No control |
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5. Forecast system and hindcasts
| Forecast frequency | daily |
|---|---|
| Forecast ensemble size | 2 per day |
| Hindcast years | 24 (1993-2016) |
| Hindcast ensemble size | 28 (4 start dates, 7 per start date) |
| Hindcast start dates | 1, 9, 17, 25 of month - 1 & 1 of month 0each month |
| On-the-fly or static hindcast set? | on-the-fly |
6. Where to find more information
GloSea5 system:
- MacLachlan, C., Arribas, A., Peterson, K. A., Maidens, A., Fereday, D., Scaife, A. A., Gordon, M., Vellinga, M., Williams, A., Comer, R. E., Camp, J., Xavier, P. and Madec, G. (2015), Global Seasonal forecast system version 5 (GloSea5): a high-resolution seasonal forecast system. Q.J.R. Meteorol. Soc., 141: 1072–1084. doi:10.1002/qj.2396
- Seasonal prediction at the Met Office
- Upgrades to the Met Office Seasonal Forecast System
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- Clayton, A. M., Lorenc, A. C. and Barker, D. M. (2013), Operational implementation of a hybrid ensemble/4D-Var global data assimilation system at the Met Office. Q.J.R. Meteorol. Soc., 139: 1445–1461. doi:10.1002/qj.2054
Blockley, E. W., Martin, M. J., McLaren, A. J., Ryan, A. G., Waters, J., Lea, D. J., Mirouze, I., Peterson, K. A., Sellar, A., and Storkey, D.: Recent development of the Met Office operational ocean forecasting system: an overview and assessment of the new Global FOAM forecasts, Geosci. Model Dev., 7, 2613-2638, https://doi.org/10.5194/gmd-7-2613-2014, 2014.
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