Description of the upgrade
A new model cycle including a major resolution upgrade was introduced on 1 February 2006.
Datasets affected
Resolution
Changed
Horizontal | Vertical |
---|
Atmospheric (changed) Wave (changed)- HRES: 0.36 degrees
- ENS: 0.5 degrees
- LAW: 0.1 degrees
|
Atmospheric (changed)
|
Meteorological content
- Increase wave spectral resolution to 24 directions and 30 frequencies (from 12 and 25 respectively) for the EPS ocean wave model.
- Use of grid-point humidity and ozone in 4D-Var.
- Revised coefficients (version 2.3) for the linearised ozone chemistry scheme, supplied by Daniel Cariolle, CERFACS.
- Use of Jason altimeter wave height data and ENVISAT ASAR spectra in the wave model data assimilation. ERS-2 SAR spectra are no longer assimilated.
Meteorological impact
- small but statistically significant improvements to deterministic 500 hPa height forecasts over Europe and for both extra-tropical hemispheres out to day 6.
- overall impact on weather parameters is modest
- precipitation scores over Europe are consistently improved, in particular for large daily rainfall amounts
- tropical temperature and wind forecasts are generally better when verified against radiosondes
- tropical cyclone position and intensity forecasts are improved in the high resolution system with some spectacular results for intense hurricanes
- increased number of observations used in the assimilation with better analysis and background departure statistics
- beneficial impact on the ocean wave analyses.
- improvements in the ocean wave forecasts
ENS
- overall benefit of the higher resolution for the ENS is reflected in the results for the probability scores which are consistently improved for 500hPa height anomalies
- improvement of the evaluation of precipitation events over Europe with respect to the Brier and ROC area scores
Technical content
Model ID and experiment number
- Atmospheric: 127
- Ocean wave: 116
- Limited-area ocean wave: 216
E-suite experiment number = 0029
Resources
ECMWF Newsletter: See Newsletter 106