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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 |
monthly run |
initialized from 10-year spin-up
Forced (obs. atmosphere) monthly run
initialized from 10-year spin-upfrom a continuous transient simulation with initial-date January 1993, started after a 10 year spinup (with climatological forcings) | Forced monthly run from a continuous transient simulation with initial-date January 1993, started after a 10 year spinup (with climatological forcings) | |
| 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 details on atmospheric DA, see ECMWF operational analysis documentation at: https://www.ecmwf.int/en/elibrary/16666-part-ii-data-assimilation
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