Cycle 38r1 summary of changes

Implementation date               

19 June 2012 See Newsletter No.132
IFS Documentation CY38R1  
Key characteristics of our current forecasting system  

Horizontal (unchanged)

  • Atmospheric
    • HRES: T1279
    • ENS: Leg A T639, Leg B T319, Leg C T255
  • Wave
    • HRES: 0.25 degrees
    • ENS: 0.5 degrees

Vertical (unchanged)

  • Atmospheric
    • HRES: L91

    • ENS: L62
    • SEAS: L91

Data set affected


Scorecard for IFS cycle 38r1

Meteorological changes


  • 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 impacts
  • High-resolution forecast performance
  • EPS forecast performance
  • Impact on the model climate
  • Impact of the new soil reanalysis
Technical changes
  • Changes to GRIB headers
  • The Extreme Forecast Index (EFI)
  • New model output parameters
Model ID 38r1
New disseminated model output


Discontinued disseminated model output None
e-suite experiment number 0058