Abstract
Abstract. This paper is a companion to the first work (Pavlos et al., 2003), which contains significant results concerning the dynamical characteristics of the magnetospheric energetic ions’ time series. The low dimensional and nonlinear deterministic characteristics of the same time series were described in Pavlos et al. (2003). In this second work we present significant results concerning the Lyapunov spectrum, the mutual information and prediction models. The dynamical characteristics of the magnetospheric ions’ signals are compared with corresponding characteristics obtained for the stochastic Lorenz system when a coloured noise perturbation is present. In addition, the null hypothesis is tested for the dynamical characteristics of the magnetospheric ions’ signal by using nonlinear surrogate data. The results of the above comparisons provide significant evidence for the existence of low dimensional chaotic dynamics underlying the energetic ions’ time series.Key words. Magnetospheric physics (energetic particles) – Radio sciences (nonlinear phenomena)
Highlights
The hypothesis of the chaotic nature of the magnetospheric behaviour has been supported in the last decade by a large number of theoretical studies (Pavlos, 1988; Baker et al, 1990; Klimas et al, 1991, 1996; Pavlos et al, 1994)
In the first work (Pavlos et al, 2003) the correlation dimension and other geometrical quantities were estimated by using the magnetospheric ions’ time series, observed during days 7–8 December 1994 at the dawn magnetosheath of the Earth’s magnetosphere, and they were used as discriminating statistics between nonlinear dynamics and linear stochastic signals
The results presented in Pavlos et al (2003) indicate clearly the existence of a nonlinear, low-dimensional dynamical process underlying the magnetospheric energetic ions’ time series
Summary
Athanasiu et al.: Magnetospheric energetic ion time series are used only as indicators of the nonlinear and chaotic behaviour of the magnetospheric dynamics. 2, the theoretical part of our study is presented in relation to the dynamical characteristics of the energetic ions’ time series. 3 a comparison between the energetic ions’ time series and the surrogate data is carried out based on the dynamical characteristics, i.e. spectrum of Lyapunov exponents, mutual information, local linear prediction and global linear and nonlinear polynomial fitting. We present some theoretical concepts concerning the spectrum of the Lyapunov exponents, the mutual information, the modeling and prediction, which constitute the main tools of our analysis
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
