Abstract
The concentration distribution of anthropocentric pollutants is favored by urban densification, affecting the micrometeorology in big cities. To examine this condition, chaos theory was applied to time series of measurements of urban meteorology and pollutants of six communes of the Metropolitan Region of Santiago de Chile, in two periods: 2010–2013 and 2017–2020. Each commune contributes, per period, six different time series: three for the meteorological variables (temperature, relative humidity, and magnitude wind speed) and three for the atmospheric pollutant concentrations (PM10, PM2.5, and CO). This qualitative study corroborates that each of the time series is chaotic through the calculation of chaotic parameters: Lyapunov exponent, correlation dimension, Hurst coefficient, correlation entropy, Lempel–Ziv complexity and fractal dimension. The variation in the chaotic parameters between the two periods can be interpreted in relation to the roughness change due to urban densification. More specific parameters, constructed from the Kolmogorov entropies and the fractal dimensions of the time series, show modifications due to the increase in the built surface in the most current period. This variation also extends to micrometeorology, as is clear from the Lempel–Ziv complexity and the Hurst coefficient. The qualitative picture constructed using chaos theory reveals that human interaction with nature affects diversity and sustainability and generates irreversible processes.
Highlights
Micrometeorology is the area of meteorology that deals with observations and processes on smaller scales of space and time [1], in the order of 1 km and measurement periods of one hour or less
If the correlation dimension is under 5.0, the Lyapunov exponent is positive, Kolmogorov’s entropy has a finite and positive value, and chaos would be present in the time series of the study
There was a decline in the CK index according to the communes where the monitoring stations are located, an antecedent that would appear insubstantial if it were not for Figure 5, below. This figure establishes a relationship between the CK index and the constructed area, preferably of height: Figure 4 shows the quotient between the sum of the Kolmogorov entropies of the meteorological variables and that of the pollutants, for the two periods 2010–2013 [17]
Summary
Micrometeorology is the area of meteorology that deals with observations and processes on smaller scales of space and time [1], in the order of 1 km and measurement periods of one hour or less. These processes are limited to the lower part of the planetary boundary layer, known as the atmospheric boundary layer (ABL) [2]. The ABL has different atmospheric regimes that respond to its sublayer structure. This structure experiences an evolution that is parallel to the diurnal cycle.
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.
