| Abstrakt: |
Coherent or synchronous motion of oscillatory components is a feature of many geoscientific systems. In this work, we review and compare different possible approaches to detect and quantify the phase coherence between time series of oscillatory systems. In particular, methods originated in the theory of phase synchronisation phenomena and the concept of recurrence plots are considered. As a particular example, the sunspot activity on both solar hemispheres and the corresponding phenomenon of north-south asymmetry are studied. It is shown that this asymmetry can be understood in terms of a different ˵phase diffusion″ of two coupled chaotic oscillators, which do however evolve coherently in time. The statistical reliability and implications of this result are discussed. Apart from the particular problem of sunspot activity, the methods described in this chapter may be used to study a variety of other phenomena in geoscientific systems, for example, the coherent motion of certain atmospheric oscillation patterns. [ABSTRACT FROM AUTHOR] |
