Coherent structure analysis of spatiotemporal chaos

We introduce a measure to quantify spatiotemporal turbulence in extended sy stems. It is based on the statistical analysis of a coherent structure deco mposition of the evolving system. Applied to a cellular excitable medium an d a reaction-diffusion model describing the oxidation of CO on Pt(100), it reveals power-law scaling of the size distribution of coherent space-time s tructures for the state of spiral turbulence. The coherent structure decomp osition is also used to define an entropy measure, which sharply increases in these systems at the transition to turbulence.