What are complex systems? 

Complex systems are characterized by many components which are interacting in a nonlinear way. Examples could be different species in an ecosystem or temperature, pressure and velocity of the flow in the atmosphere or the ocean. We study the emergence of a complex temporal evolution of such nonlinear dynamical systems as well as the formation of spatial or spatio-temporal pattern in spatially extended systems or complex networks with a special emphasis of applications in climate and earth system science. In nonlinear systems a complicated interplay of “ordered” dynamics like e.g. coherent structures and “random” behavior is observed depending on different environmental conditions. We study under which conditions “order” and “chaos or irregularity” can be expected. Our research is aimed at the development of a methodological basis to analyze nonlinear dynamical systems described by models or given by observational data. 

Our main subjects of research are: 

    • Formation of spatio-temporal patterns in ocean, atmosphere and ecosystems
    • Response of systems with respect to various perturbations, like e.g. man-made perturbations or fluctuating environmental conditions, which finally may lead to a qualitative new behavior: tipping phenomena (critical transitions) and resilience
    • Prediction of tipping phenomena, like extinction of species
    • Interaction of different parts of the earth system, e.g. the interplay between hydrodynamic flows and species distribution
    • Synchronization phenomena between coupled systems, like neurons in the brain of patches of populations
    • External control of environmental systems or internal control by evolution