The new cycle includes a collection of improvements to the forecast model and the data assimilation system, affecting the high-resolution forecasts and analyses, the ensemble of data assimilations (EDA) and the ensemble prediction system including its monthly extension.
Implemented: 19 June 2012
Resolution
Unchanged from previous IFS cycle.
Horizontal
Vertical
Atmospheric (unchanged)
HRES: T1279
ENS: Leg A T639, Leg B T319, Leg C T255
Wave (unchanged)
HRES: 0.25 degrees
ENS: 0.5 degrees
Atmospheric (unchanged)
HRES: L91
ENS: L62
SEAS: L91
Meteorological content
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