\chapter{Model history}
The roots of CAT go back to the $2$D-turbulence model developed by
Annalisa Bracco, see e.g.\ \cite{braccoandmcwilliams2010}. The original
model was redesigned in order to CAT integrate into the Planet Simulator 
model platform (PlaSim) \cite{fraedrichetal1998}. The CAT code was 
rewritten from scratch \cite{borthetal2016} and complemented by a 
new stand-alone fft-library. Through the integration into the PlaSim 
platform the user of CAT has at his disposal a graphical user interface 
and a full model development environment. It is also possible to run
CAT as a stand-alone application.