Weng Yu-Chi, Chang Ni-Bin, Lee T Y
Department of Urban an Environmental Engineering, Kyoto University, Kyoto, Japan.
J Environ Manage. 2008 May;87(3):405-14. doi: 10.1016/j.jenvman.2007.01.023. Epub 2007 Mar 21.
The ozone pollution at ground level in rural and urban areas has been a long-standing problem in the world. This paper focuses on estimating self-affined nature of nonlinearity of ground-level peak ozone time series, which is analyzed by two nonlinear fractal statistical methods, including R/S analysis and BDS test. To explore the underlying structure of ozone observations at ground level and improve the forecasting capacity in urban region, practical implementation was assessed by a case study via collecting and analyzing the monitoring data at Chaojhou and Zenwu in the Kaohsiung metropolitan region, Taiwan. Based on R/S analysis, the time series can be identified as persistent and long-memory processes with Hurst exponents of both about 0.75. In addition, the V statistics specifies possible fluctuation cycle lengths of 32, 170, and 420 day simultaneously. Such results are consistent with the regional meteorological conditions leading to help characterize the regional scale ozone behavioral trend. Furthermore, the BDS test results confirm a strong nonlinearity of both time series associated with these two cities. Yet in both cases, nonlinearity implies chaos. The R/S analysis and BDS test provide strong evidence for nonlinearity and fractality of ozone time series due to noisy chaos, and we could not rule out the possibility of deterministic chaos in tropospheric ozone system.
农村和城市地区地面臭氧污染一直是全球长期存在的问题。本文着重估计地面臭氧峰值时间序列非线性的自仿射性质，采用重标极差分析（R/S分析）和BDS检验这两种非线性分形统计方法进行分析。为探究地面臭氧观测的潜在结构并提高城市地区的预测能力，通过收集和分析台湾高雄都会区潮州和仁武的监测数据，以案例研究的方式进行了实际评估。基于R/S分析，该时间序列可被识别为具有持续性和长记忆性的过程，赫斯特指数均约为0.75。此外，V统计量同时指定了可能的波动周期长度为32天、170天和420天。这些结果与区域气象条件一致，有助于刻画区域尺度臭氧的行为趋势。此外，BDS检验结果证实了与这两个城市相关的两个时间序列都具有很强的非线性。然而在这两种情况下，非线性意味着混沌。R/S分析和BDS检验为臭氧时间序列因噪声混沌而具有非线性和分形性提供了有力证据，并且我们不能排除对流层臭氧系统中确定性混沌的可能性。
