I. Analysis change

a. Improved time interpolation

previously use 0 and 6 hour forecast. Now use 3, 6, and 9 hour forecast.

b. Nonlinear analysis

direct use of SSMI wind speed, allow for nonlinearity in observation and constraints.

c. Limiting supersaturation and negative moisture

part of the benefit of the nonlinear analysis

d. Reformulated background error

allow spatially varying background error

e. 3-D ozone

important for the direct use of radiance instead of retrieval

f. Changes in the processing of the 1-b data

better radiative transfer computation, more polar orbiting obs

g. Including GOES radiances

one advantage of the better radiative transfer code

II. Model Physics change

a. Land surface parameterization upgrade

better land surface specifications of vegetation cover, soil and vegetation types.

modifications to canopy and transpiration formulation

modification of snow treatment

improved runoff parameterization

b. Convection changes

closure modification over ocean to reduce bulls-eye problem

c. Gravity wave drag enhancement

orographic asymmetry and convexity inclusion and wind direction sensitive drag

d. Short-wave radiation

multi spectral band codes replacing the old bulk routine

e. Cloud determination

better tuning of cloud-RH formulation based on observations

f. Prognostic ozone

for the analysis of satellite observed radiances

III. Resolution increase

T170L42