NPG Nonlinear Processes in Geophysics NPG Nonlin. Processes Geophys. 1607-7946 Copernicus Publications Göttingen, Germany 10.5194/npg-6-79-1999 Nonlinear analysis of magnetospheric data Part II. Dynamical characteristics of the AE index time series and comparison with nonlinear surrogate data Pavlos G. P. 1 Kugiumtzis D. 2 Athanasiu M. A. 1 Hatzigeorgiu N. 3 Diamantidis D. 1 Sarris E. T. 1 Department of Electrical and Computer Engineering, Demokritos University of Thrace, 67100 Xanthi, Greece Max-Planck Institute for Physics of Complex Systems, 01187 Dresden, Germany Institute for Language and Speech Processing, Xanthi Branch, Greece 30 06 1999 6 2 79 98 Copyright: © 1999 G. P. Pavlos et al. 1999 This work is licensed under the Creative Commons Attribution-NonCommercial-ShareAlike 2.5 Generic License. To view a copy of this licence, visit https://creativecommons.org/licenses/by-nc-sa/2.5/ This article is available from https://npg.copernicus.org/articles/6/79/1999/npg-6-79-1999.html The full text article is available as a PDF file from https://npg.copernicus.org/articles/6/79/1999/npg-6-79-1999.pdf

In this study we have used dynamical characteristies such as Lyapunov exponents, nonlinear dynamic models and mutual information for the nonlinear analysis of the magnetospheric AE index time series. Similarly with the geometrical characteristic studied in Pavlos et al. (1999b), we have found significant differences between the original time series and its surrogate data. These results also suggest the rejection of the null hypothesis that the AE index belongs to the family of stochastic linear signals undergoing a static nonlinear distortion. Finally, we believe that these results support the hypothesis of nonlinearity and chaos for the magnetospheric dynamics.