The main aim of this session is to use concepts of dynamical systems for understanding nonlinear mechanisms and processes responsible for low-frequency variability (LFV) on seasonal to decadal and centennial time scales of the atmosphere, the ocean and the climate system. In the framework of such concepts, LFV can arise from irregular transitions between distinct atmospheric and oceanic regimes as well as from the
interaction between low- and high-frequency modes. The session will discuss how natural variations due to internal nonlinear dynamical processes within the atmosphere-ocean-climate system might contribute to observed decadal climate variability? What kind of circulation regimes occur, what is their origin, and how they have changed in the past and could change in the future? Modelling studies are encouraged to span the range of model hierarchy from idealised models to complex coupled AOGCMs.