Spectral, multifractal and informational analysis of PM10 time series measured in Mexico City Metropolitan Area

Abstract

Atmospheric pollution in Mexico City Metropolitan Area (MCMA) represents a serious social and economic concern due to the very high population density. The most important industrial activities are the main responsible of the production of particulate matter PM10 that can damage seriously the human respiratory system. In the present study we investigate the dynamical properties of the time series of PM10 emissions recorded from 2005 to 2016 by the Automatic Atmospheric Monitoring Network (RAMA) in five zones of MCMA (NW, NE, CE, SW and SE). Several methods (periodogram, multifractal detrended fluctuation analysis and the Fisher–Shannon method) were applied to get the most exhaustive description of the dynamical characteristics of the series. Our findings point out to: (1) the existence of a twofold power law behavior in the power spectrum of all the series, indicating the co-existence of two different mechanisms underlying the time dynamics of PM10; (2) the emergence of the 7-day periodicity of anthropogenic nature; (3) the multifractal behavior of all the series, dominated by small fluctuations; (4) the identification of NE zone, which is also the most polluted one as characterized by the larger disorder.