Description of the upgrade

A new model cycle including a major resolution upgrade was introduced on 1 February 2006.

Implemented: 01 February 2006

Datasets affected

Changed

Horizontal

Vertical

Atmospheric (changed)

Wave (changed)

Atmospheric (changed)

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.

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

E-suite experiment number = 0029