Journal cover Journal topic
Nonlinear Processes in Geophysics An interactive open-access journal of the European Geosciences Union
Journal topic

Journal metrics

Journal metrics

  • IF value: 1.558 IF 1.558
  • IF 5-year value: 1.475 IF 5-year
    1.475
  • CiteScore value: 2.8 CiteScore
    2.8
  • SNIP value: 0.921 SNIP 0.921
  • IPP value: 1.56 IPP 1.56
  • SJR value: 0.571 SJR 0.571
  • Scimago H <br class='hide-on-tablet hide-on-mobile'>index value: 55 Scimago H
    index 55
  • h5-index value: 22 h5-index 22
Volume 17, issue 2
Nonlin. Processes Geophys., 17, 93–101, 2010
https://doi.org/10.5194/npg-17-93-2010
© Author(s) 2010. This work is distributed under
the Creative Commons Attribution 3.0 License.
Nonlin. Processes Geophys., 17, 93–101, 2010
https://doi.org/10.5194/npg-17-93-2010
© Author(s) 2010. This work is distributed under
the Creative Commons Attribution 3.0 License.

  05 Mar 2010

05 Mar 2010

Predictability of the monthly North Atlantic Oscillation index based on fractal analyses and dynamic system theory

M. D. Martínez1, X. Lana2, A. Burgueño3, and C. Serra2 M. D. Martínez et al.
  • 1Dept. de Física Aplicada, Universitat Politècnica de Catalunya, Av. Diagonal 649, 08028 Barcelona, Spain
  • 2Dept. de Física i Enginyeria Nuclear, Universitat Politècnica de Catalunya, Av. Diagonal 647, 08028 Barcelona, Spain
  • 3Dept. d'Astronomia i Meteorologia, Universitat de Barcelona, C./ Martí Franquès 1, 08028 Barcelona, Spain

Abstract. The predictability of the monthly North Atlantic Oscillation, NAO, index is analysed from the point of view of different fractal concepts and dynamic system theory such as lacunarity, rescaled analysis (Hurst exponent) and reconstruction theorem (embedding and correlation dimensions, Kolmogorov entropy and Lyapunov exponents). The main results point out evident signs of randomness and the necessity of stochastic models to represent time evolution of the NAO index. The results also show that the monthly NAO index behaves as a white-noise Gaussian process. The high minimum number of nonlinear equations needed to describe the physical process governing the NAO index fluctuations is evidence of its complexity. A notable predictive instability is indicated by the positive Lyapunov exponents. Besides corroborating the complex time behaviour of the NAO index, present results suggest that random Cantor sets would be an interesting tool to model lacunarity and time evolution of the NAO index.

Publications Copernicus
Download
Citation