Implementation date

9 November 2010

See Newsletter No.126
Key characteristics of our current forecasting system  
Resolution

Horizontal  (unchanged)

  • Atmospheric
    • HRES: TL1279
    • ENS: Leg A TL399
  • Wave
    • HRES: 0.36 degrees
    • ENS: 0.5 degrees
    • LAW: 0.1 degrees

Vertical (unchanged)

  • Atmospheric
    • HRES: L91
    • ENS: L62
Data set affected
  • HRES
  • ENS
Meteorological changes
  • Five-species prognostic microphysics scheme, introducing cloud rain water content, and cloud ice water content as new model variables.
  • Retuning and simplification of convective entrainment/detrainment and land/sea dependent threshold for precipitation
  • Retuning of subgrid-scale orographic gravity wave drag
  • Adjustment to diffusion in stable boundary Iayers near the surface
  • All-sky improvements of microwave radiance assimilation
  • Adaptation to neutral wind of the observation operator for scatterometer data
  • New soil-moisture analysis scheme (SEKF, simplified ensemble Kalman filter)
  • New snow analysis based on 0I (Optimum Interpolation), and upgrade of NESDIS snow cover data to 4 km resolution.
  • Monthly varying climatology of leaf area index (LAI) based on MODIS data
  • The 4D-Var of the Early Delivery suite performs 2 rather than 3 updates of the outer loop

ENS

  • Revision of stochastically perturbed physical tendencies
  • Introduction of spectral stochastic backscatter scheme
  • Retuned initial perturbation amplitudes
Meteorological impacts
  •  Benefit in terms of objective scores in the medium range in both hemispheres, particularly in the upper troposphere.
  •  positive verification for winds against observations, whereas verification against analyses tends to be negative in the shorter range, which can be explained by higher variability in the analysed wind fields.
  • improved snow analysis issues that affected the analysed snow depth on the 2009/2010 winter
  • modifications to the stable boundary layer improve the diurnal cycle of 2m temperature, especially some reduction of the night-time cold bias over Europe
  • improved tropospheric humidity analysis

ENS

  • improved probabilistic scores in the extra-tropics
  • better tuned spread-skill relationship - especially for 500 hPa geopotential height in the earlier forecast ranges (days 1-5)
Technical changes  
Model ID
  • Atmospheric: 139
  • Ocean wave: 107
  • Limited-area ocean wave: 207
New disseminated model output

Listed below

Param Id  

Parameter name

Short name

Unit  

Type

Availability

8

Surface run off

sro

m

sfc

fc, full EPS

9

Sub-surface run off

ssro

m

sfc

fc, full EPS

66

Leaf area index, low vegetation

lai_lv

m**2/m**2

sfc

an, fc

67

Leaf area index, high vegetation

lai_hv

m**2/m**2

sfc

an, fc

75

Cloud Rain Water Content

crwc

kg/kg

ml

an, fc, full EPS

76

Cloud Snow Water Content

cswc

kg/kg

ml

an, fc, full EPS

228003

Friction velocity

zust

m/s

sfc

fc

228023

Cloud Base Height

cbh

m

sfc

fc, full EPS

228024

Zero Degree Level

deg0l

m

sfc

fc, full EPS

228131

Neutral Wind at 1m u- component

u10n

m/s

sfc

fc

228132

Neutral Wind at 1m v- component

v10n

m/s

sfc

fc

Discontinued disseminated model output -  
e-suite experiment number 0051