MEASURING CHAOS FROM SPATIAL INFORMATION

A new class of Lyapunov exponents are calculated from a simple numeric al approach based on a spatially defined average of local divergence o f trajectories. This is a new way of identifying chaos in ecological d ata where, because of its limited length and quality, current techniqu es derived from the dynamical systems theory are not applicable. In th e examples presented, only a very short time series (around 10 time st eps) is necessary for obtaining a close estimate of the spatiotemporal Lyapunov exponent if the lattice size is high enough. The method is a pplied to three previously studied coupled map lattice models and is s hown to be a good measure for spatiotemporal chaos and an alternative way of estimating the underlying dimension. (C) 1995 Academic Press Li mited