Implemented: 10 March 2009  

Datasets affected

  • HRES
  • ENS




Atmospheric (unchanged)
  • HRES: TL799
  • ENS: Leg A TL399
Wave (unchanged)
  • HRES: 0.25 degrees
  • ENS: 0.5 degrees

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

Meteorological content

  • Revised snow scheme including a diagnostic liquid water storage and a new density formulation
  • Revised ozone chemistry
  • Active assimilation of IASI humidity channels and consistent use of AIRS and IASI humidity channels.
  • Activate all-sky 4D-VAR assimilation of microwave imagers
  • Increase of the weight to GPS radio occultation data above 26 km, and use of the data up to 50 km
  • Various satellite-related modifications, including activation of version 9 of the radiative transfer software package RTTOV-9 (developed by NWP-SAF) and revised HIRS cloud detection
  • TL/AD longwave radiation (removal of the neural network), optimization of the non-linear code for simplified longwave radiation and optimization (NL, TL, AD) of the shortwave radiation scheme
  • Extend the domain of the wave model from 81 º to 90 º North
  • Use of ERA-interim analyses for the EFI reforecasts

Meteorological impact

Overall the new cycle is neutral in terms of verification scores for both hemispheres and the tropics.
  • Improvements to 2m temperature bias and slightly better performance for recent tropical cyclones in both position and intensity.
  • Synoptic performance is generally similar to current operations.
  • Impact on EFI from the change to using ERA-interim analyses for its reforecasts is not substantial.

Technical content

Model ID and experiment number

  • Atmospheric: 134
  • Ocean wave: 119
  • Limited-area ocean wave: 219

E-suite experiment number = 0042


ECMWF Newsletter: See Newsletter 121