Description of the upgrade
The new cycle includes a collection of improvements to the forecast model and the data assimilation system, affecting the high-resolution forecasts and analyses, the ensemble of data assimilations (EDA) and the ensemble prediction system including its monthly extension.
Resolution
Unchanged from previous IFS cycle.
| Horizontal | Vertical |
|---|
Atmospheric (unchanged) - HRES: T1279
- ENS: Leg A T639, Leg B T319, Leg C T255
Wave (unchanged)- HRES: 0.25 degrees
- ENS: 0.5 degrees
| Atmospheric (unchanged) - HRES: L91
- ENS: L62
- SEAS: L91
|
Meteorological content
- Updated background-error covariance statistics (for Jb) based on the cycle 37r2 EDA
- Improved statistical filtering of EDA sampled background errors.
- Assimilation of MHS channel 5 over land and the all-sky radiance product from SEVIRI on board Meteosat-9 (the OSCAT scatterometer data on board the Indian Oceansat-2 satellite will be monitored)
- Modified convective downdraught entrainment
- Changes to cloud ice fall speed, ice supersaturation, melting of ice to rain and freezing timescale of rain
- Improved de-aliasing of the pressure gradient term, reducing numerical noise, allowing a reduction of the horizontal diffusion in the forecast
- Improved description of swell
- Use of a new surface reanalysis to initialize the surface fields in the EPS hindcasts
- Extension of the EPS hindcast years from 18 to 20, all based on ERA-interim initial data
- EDA perturbations redefined using the EDA ensemble mean instead of the EDA control as the reference
Meteorological impact
- High-resolution forecast performance
- EPS forecast performance
- Impact on the model climate
- Impact of the new soil reanalysis
Evaluation
Scorecard ENS
New and changed parameters
New parameters
None
Changes to existing parameters
None
Technical content
- Changes to GRIB headers
- The Extreme Forecast Index (EFI)
- New model output parameters
Model ID and experiment number
Model ID = 38r1
E-suite experiment number = 0058
Resources
ECMWF Newsletter: See Newsletter 132