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Comment:
Added new parameters from the summary of changes web page https://www.ecmwf.int/en/forecasts/documentation-and-support/evolution-ifs/cycles/cycle-36r4-summary-changes
Description of the upgrade
Cycle 36r4 included a new cloud parametrization scheme and new surface analysis schemes for snow and soil moisture.
| Note |
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Implemented: 09 November 2010 |
Datasets affected
- HRES
- ENS
Resolution
Unchanged
| Horizontal | Vertical |
|---|---|
Horizontal (unchanged)
| Vertical (unchanged)
|
Meteorological content
- Five-species prognostic microphysics scheme, introducing cloud rain water content, and cloud ice water content as new model variables.
- Retuning and simplification of convective entrainment/detrainment and land/sea dependent threshold for precipitation
- Retuning of subgrid-scale orographic gravity wave drag
- Adjustment to diffusion in stable boundary Iayers near the surface
- All-sky improvements of microwave radiance assimilation
- Adaptation to neutral wind of the observation operator for scatterometer data
- New soil-moisture analysis scheme (SEKF, simplified ensemble Kalman filter)
- New snow analysis based on 0I (Optimum Interpolation), and upgrade of NESDIS snow cover data to 4 km resolution.
- Monthly varying climatology of leaf area index (LAI) based on MODIS data
- The 4D-Var of the Early Delivery suite performs 2 rather than 3 updates of the outer loop
ENS
- Revision of stochastically perturbed physical tendencies
- Introduction of spectral stochastic backscatter scheme
- Retuned initial perturbation amplitudes
Meteorological impact
- Benefit in terms of objective scores in the medium range in both hemispheres, particularly in the upper troposphere.
- positive verification for winds against observations, whereas verification against analyses tends to be negative in the shorter range, which can be explained by higher variability in the analysed wind fields.
- improved snow analysis issues that affected the analysed snow depth on the 2009/2010 winter
- modifications to the stable boundary layer improve the diurnal cycle of 2m temperature, especially some reduction of the night-time cold bias over Europe
- improved tropospheric humidity analysis
ENS
- improved probabilistic scores in the extra-tropics
- better tuned spread-skill relationship - especially for 500 hPa geopotential height in the earlier forecast ranges (days 1-5)
New and changed parameters
New parameters
8 | Surface run off | sro | m | sfc | fc, full EPS |
9 | Sub-surface run off | ssro | m | sfc | fc, full EPS |
66 | Leaf area index, low vegetation | lai_lv | m** |
2/m**2 | sfc | an, fc | |||
67 | Leaf area index, high vegetation | lai_hv | m**2/m**2 | sfc | an, fc |
75 | Cloud Rain Water Content | crwc | kg/kg | ml | an, fc, full EPS |
76 | Cloud Snow Water Content | cswc | kg/kg | ml | an, fc, full EPS |
228003 | Friction velocity | zust | m/s | sfc | fc |
228023 | Cloud Base Height | cbh | m | sfc | fc, full EPS |
228024 | Zero Degree Level | deg0l | m | sfc | fc, full EPS |
228131 | Neutral Wind at 1m u- component | u10n | m/s | sfc | fc |
228132 | Neutral Wind at 1m v- component | v10n | m/s | sfc | fc |
Resources
ECMWF Newsletter: See Newsletter 126
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