Description of the upgrade

The T106 model became operational. The spectral representation in the horizontal is truncated at wavenumber 106. The vertical resolution was not changed.
The vertical diffusion scheme was modified which allows larger time-steps to be used (t = 900s). A parametrisation scheme of shallow cumulus convection has been introduced.
The Kuo cumulus convection scheme has been replaced by a modified Kuo scheme.
Evaporation of large-scale rain and melting of snow have been reformulated.
A new cloud prediction scheme was formulated to overcome the deficiencies of the previous scheme (too many deep clouds, too little tropical cirrus, too little subtropical cloudiness, poor representation of the diurnal variation in cloudiness).
Sea ice has been re-specified and is now assumed to exist whenever sea temperatures are below -2°C (previously 0°C).

Implemented: 01 May 1985