Ten organising principles for coupling in multiphysics and multiscale models

Computational science faces new challenges posed by multiphysics and multiscale, or more generally put, coupled models. These systems are composites formed from separate subsystem models that interact via data exchanges. These data dependencies pose a coupling problem, and on distributed memory computers, a parallel coupling problem. This article presents a definition of terms and a set of organising prin-ciples for the coupling and parallel coupling problems. It is meant as a first step towards creating a theory of coupled models. These prin-ciples are then employed in a case study of a coupled climate model and offer remarkable insight into its structure.