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.

Datasets affected

• HRES
• ENS

Resolution

Unchanged

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

Resources

ECMWF Newsletter: See Newsletter 113