Description of the upgrade

A new analysis system was implemented which makes better use of observations; data and differences from the first-guess will be used at reported levels. This will effectively increase the actual vertical resolution of the analysis, in particular in the boundary layer and near the tropopause.
Unnecessary vertical interpolation of analysis increments between model and standard pressure levels are eliminated. Analysis increments on the Gaussian grid of the model were evaluation (1.125° resolution).
The data selection criteria in boxes of flexible depending on data sensity and extending over the depth of the troposphere were improved.
A univariate optimum interpolation scheme replaced the correction scheme for the analysis of humidity.

Implemented: 09 September 1986