Description of the upgrade

The new cycle includes significant changes to the model physics, including the convection scheme, that increase the model activity in the tropics.

Implemented: 06 November 2007  

Datasets affected

  • HRES
  • ENS




Atmospheric (unchanged)
  • HRES: TL799
  • ENS: Leg A TL399
Wave (unchanged)
  • HRES: 0.36 degrees
  • ENS: 0.5 degrees
  • LAW: 0.1 degrees

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

Meteorological content

  • New formulation of convective entrainment and relaxation timescale
  • Reduction in free atmosphere vertical diffusion
  • New soil hydrology scheme
  • New radiosonde temperature and humidity bias correction
  • Increase in number of radio occultation data from COSMIC
  • Assimilation of AMSR-E, TMI, SSMIS window channels (clear sky)
  • Assimilation of SBUV ( NOAA-17, NOAA-18) and monitoring of OMI ozone data
  • Corrections to the radiation post-processing in the IFS will correct/improve the following parameters:
    • 57 (UVB) Downward UV radiation at the surface
    • 58 (PAR) Photosynthetically active radiation at the surface
    •  59 (CAPE) Convective available potential energy
  • initial perturbation amplitude reduced by 30%
  • singular vectors targeted on tropical cyclones are computed with the new moist physics package in the tangent-linear and adjoint models (as used in the operational in 4D- Var since cycle 32r2).

Meteorological impact

  • improved scores for the extra-tropical southern hemisphere throughout the forecast range, and for the northern hemisphere in the first half of the forecast
  • substantial improvement to the lower tropospheric winds in the tropics compared to observations
  • reduction in the biases of 2m temperature mainly over the Americas
  • improved precipitation forecasts over Europe
  • reduction of the initial perturbation amplitude resulted in a good match of spread and ensemble mean error
  • probabilistic skill is generally improved at mid-latitudes
  • improved reliability of the tropical cyclone strike probability forecasts
  • neutral impact in the extra-tropics
  • beneficial impact on probabilistic precipitation forecasts over Europe.

New and changed parameters

New parameters

Four new pressure levels in the analyses and HRES forecast runs: 600, 800, 900 and 950 hPa.

Technical content

Model ID and experiment number

  • Atmospheric: 130
  • Ocean wave: 116
  • Limited-area ocean wave: 216

E-suite experiment number = 0035


ECMWF Newsletter: See Newsletter 113