2. Introduction

General circulation model (GCM) is now widely used for various scientific problems.
numerical weather prediction.
study of climate change
simulation of Mars and Venus atmosphere

As a consequence, current GCMs become to be a very complicated, and specialized model.
fully complicated softwares.
empirical formulas and techniques for each planets are "hard coded"

Therefore, current GCMs are not useful for 
 1) comparative study of planetary atmosphere,
 2) understanding dynamics of atmospheric general circulation.