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

  • HRES
  • ENS
  • Wave




Atmospheric (changed)
  • HRES: TL799
  • ENS: TL399
Wave (changed)
  • HRES: 0.36 degrees
  • ENS: 0.5 degrees
  • LAW: 0.1 degrees

Atmospheric (changed)
  • HRES: L91
  • ENS: L62

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
  • 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


ECMWF Newsletter: See Newsletter 106