Articles | Volume 8, issue 4
Development and technical paper
29 Apr 2015
Development and technical paper |  | 29 Apr 2015

The software architecture of climate models: a graphical comparison of CMIP5 and EMICAR5 configurations

K. Alexander and S. M. Easterbrook

Abstract. We analyze the source code of eight coupled climate models, selected from those that participated in the CMIP5 (Taylor et al., 2012) or EMICAR5 (Eby et al., 2013; Zickfeld et al., 2013) intercomparison projects. For each model, we sort the preprocessed code into components and subcomponents based on dependency structure. We then create software architecture diagrams that show the relative sizes of these components/subcomponents and the flow of data between them. The diagrams also illustrate several major classes of climate model design; the distribution of complexity between components, which depends on historical development paths as well as the conscious goals of each institution; and the sharing of components between different modeling groups. These diagrams offer insights into the similarities and differences in structure between climate models, and have the potential to be useful tools for communication between scientists, scientific institutions, and the public.

Short summary
This paper describes an analysis of the software architecture of global climate models. The analysis provides a visualization of the structure of these models, and reveals interesting differences between the models developed at different research labs.