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| Hindcast | Forecast | |
|---|---|---|
| Atmosphere initialization | ERA5 | ECCC GEPS |
| Atmosphere IC perturbations | Random isotropic perturbations | Ensemble Kalman Filter |
Land Initialization | Off-line ISBA-based Surface Prediction System (SPSv6.2) forced by 1-hourly lowest-level ERA5 fields | ECCC GDPS output adjusted to hindcast climatology |
| Land IC perturbations | None | None |
| Soil moisture initialization | Off-line ISBA-based Surface Prediction System (SPSv6.2) forced by 1-hourly lowest-level ERA5 fields | ECCC GDPS output adjusted to hindcast climatology |
| Snow initialization | Off-line ISBA-based Surface Prediction System (SPSv6.2) forced by 1-hourly lowest-level ERA5 fields | ECCC GDPS output with prescribed climatological snow over Tibetan Plateau |
| Unperturbed control forecast? | None | None |
Data assimilation method for control analysis:
Horizontal and vertical resolution of perturbations:
Perturbations in +/- pairs:
Detailed documentation:
Gauthier, P., et al. 1999: Background-error statistics modelling in a 3D variational data assimilation scheme: Estimation and impact on the analyses. Proc. ECMWF Workshop on Diagnosis of Data Assimilation Systems, Reading, United Kingdom, ECMWF, 131–145,
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6. Forecast system and hindcasts
| Forecast frequency | 12-month forecast is produced on the last day of each month |
|---|---|
| Forecast ensemble size | 20 (ensemble members 1-10 initialized at 00Z on last day of month, 11-20 at 00Z on 5th to last day of month) |
| Hindcast years | 1980-2023 |
| Hindcast ensemble size | 20 (ensemble members 1-10 initialized at 00Z on first day of month, 11-20 at 00Z on 5th to last day of previous month) |
| On-the-fly or static hindcast set? | static |
| Calibration (bias correction) period | 1991-2020 |
7. Other relevant information
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Vertical interpolation pressure levels:
- For temp/phi near the surface, log-linear interpolation (linear in ln(eta)) with the lapse rate of 6.5e-3 deg/m
- For remaining variables near the surface and all variables near the top, constant extrapolation, i.e. keep same value from the closest model level
8. Where to find more information
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