Complex climate models — tools for studying the origin of stochasticity in the climate system

Abstract

The most complex climate models are general circulation models (GCMs) of the atmosphere and the ocean. The structure of the state-of-art GCMs is described. The complexity of a GCM originates, to a large extent, from the representation of the forcing terms in the underlying equations. These terms involve small-scale or even molecular-scale processes. It is shown that fluctuations produced by these processes supply the slow climate components with energy through non-linear processes. As a consequence, the variability behavior in an integration with a complex model that represents these small-scale processes is generally different from that in an integration with a simple model that neglects these processes.KeywordsPrimitive EquationVertical DiffusionStratiform CloudECHAM ModelSynoptic EddyThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.