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Coupling frequency: 3-hourly coupling between atmosphere-land and ocean--sea-ice.
(Better use more specific question? Here or elsewhere?)
The coupled model Global Coupled 2 (GC2) is described in Williams et al, 2015.
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Global Atmosphere 6.0 & Global Land 6.0: Walters et al, 2017More model details? (e.g. land surface model?)
2.1 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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3. Initialization and initial condition (IC) perturbations
3.1 Atmosphere and land
| Re-forecastHindcast | Forecast | |
|---|---|---|
| Atmosphere initialization | ERA-Interim | Met Office Global Hybrid 4D-VAR |
| Atmosphere IC perturbations | None | None |
Land Initialization | Climatology/ERA-Interim | Climatology/Met Office Global Hybrid 4D-VAR |
| Land IC perturbations | None | None |
| Soil moisture initialization | Climatology | Climatology |
| Snow initialization | ERA-Interim | Met Office Global 4D-VAR |
| Unperturbed control forecast? | No | No |
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Met Office Global Hybrid 4D-VAR: Clayton et al, 2013
More DA details? CM:
Data assimilation method for control analysis: 4D Var (atmosphere) and 3DVAR (ocean/sea-ice)
Horizontal and vertical resolution of perturbations: N/A
Perturbations in +/- pairs: N/A
3.2 Ocean and cryosphere
| Re-forecastHindcast | 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 GS-OSIA and the FOAM system both use the Nucleus for European Modelling of the Ocean data assimilation system (NEMOVAR). This is a 3d-VAR data assimilation scheme. The GS-OSIA uses different surface forcing (ERA-interim) and observation sets as it is a historical analysis. FOAM uses surface forcing from the Met Office Global NWP model and real-time observations.
Source and treatment of SST? (Other data sources - altimetry?)The common NEMOVAR system is described in Blockley et al, 2014. Details of the GS-OSIA can be found in MacLachlan et al, 2015.
More ocean data assimilation details?
4. Model uncertainties perturbations:
| Model dynamics perturbations | None |
|---|---|
| Model physics perturbations | Atmosphere Stochastic 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 | Dailydaily |
|---|---|
| Forecast ensemble size | 2 per day |
| Hindcast years | 23 (1993-2015) |
| Hindcast ensemble size | 28 (4 start dates, 7 per start date) |
| Hindcast start dates | 9, 17, 25 of Month month - 1 & 1 of Month month 0 |
| On-the-fly or static hindcast set? | on-the-fly |
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