Cycle 40r1 summary of changes

Implementation date 19 Nov 2013 See Newsletter No.138 p3
IFS Documentation CY40R1  
Detailed description of changes  
Key characteristics of our current forecasting system  
Resolution

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

  • Atmospheric
    • HRES: L137
    • ENS: L91 (prev L62)

 

Data set affected

  • HRES
  • ENS
Score card Comparison of scores of model cycle 40r1 and cycle 38r2
Meteorological changes
Forecast
  • Convection
  • Vertical diffusion in stable conditions
  • Turbulent orographic drag
  • Orographic gravity
  • Increase in the surface - atmosphere coupling for forest areas
  • ENS
    • Vertical resolution (from 62 to 91)
    • Atmosphere-ocean coupling now active from initial forecasts time
    • Perturbation of land surface initial conditions
    • Perturbation of land surface temperature
  • Waves
    • Changes to shallow water calculation and surface air density
Analysis
  • Dynamic estimation of background error covariances for 4DVAR with enhanced 25-members EDA
  • SSMIS 183 GHz channels activated in all-sky microwave radiance assimilation
  • Enhanced use of AMSU-A, AMSU-B and MHS data over sea ice
  • Situation-dependent observation errors and revised quality-control for AMVs
  • Use of calibrated EDA spread in radiance space as background error estimate for the FG-check for ATOVS
Meteorological impacts
  • Upper air
  • Weather parameters
  • Monthly forecast
  • Synoptic aspects
Technical changes
Model ID
  • Atmospheric: 144
  • Ocean wave: 110
  • Limited-area ocean wave: 210
New disseminated model output

None

Discontinued disseminated model output None
e-suite experiment number 0063 (from 20/08/2013)