Title: Chaotic time series analysis of acid rain in Türkiye

Authors: Aysegul Sener; Gonca Tuncel; Mirac Kamislioglu

Addresses: The Graduate School of Natural and Applied Sciences, Dokuz Eylul University, Izmir, Türkiye ' Department of Industrial Engineering, Dokuz Eylul University, 35390, Izmir, Türkiye ' Medical Imaging Department, Vocational School of Health Services, Bandırma Onyedi Eylul University, 10200, Balıkesir, Türkiye

Abstract: Acid rain is an environmental problem that negatively affects nature and people globally. As a signal processing method, chaotic time series analysis is useful for understanding the behaviour of complex dynamic systems. This study aims to identify the chaotic behaviour of the dynamic system of acid rain characteristics, including the pH level, nitrate, and sulphate concentrations. A dataset from four rain collection stations in Türkiye between 2005 and 2022 is used to investigate the underlying dynamics and spatial distribution. The phase space is reconstructed, and the embedding parameters are obtained using Lyapunov exponentials, power spectral density, Hurst exponential, and mutual information functions to determine and predict the nonlinear properties of acid rain. Time series analyses revealed that the chemical components in acid rain demonstrated strongly nonlinear properties. Positive Lyapunov exponents prove the exponential divergence of the trajectories, which support the presence of chaos in the acid rain characteristics.

Keywords: nonlinear processes; dynamic system modelling; Lyapunov exponent; acid rain; Türkiye.

DOI: 10.1504/IJGW.2024.135360

International Journal of Global Warming, 2024 Vol.32 No.1, pp.1 - 28

Received: 09 Feb 2023
Accepted: 14 May 2023
Published online: 06 Dec 2023 *