Description of the upgrade

Cycle 36r4 included a new cloud parametrization scheme and new surface analysis schemes for snow and soil moisture.

Implemented: 09 November 2010

Datasets affected

Unchanged

Horizontal

Vertical

Horizontal (unchanged)

Vertical (unchanged)

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

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)