On the Nature of Air Pollution Dynamics in Mexico City-1. Nonlinear Analysis

The primary air-pollution problem in Mexico City is the formation of photochemical smog, in particular ozone. In addition, photochemical oxidants accelerate the conversion of sulfur dioxide into sulfates, which interact with radiation, decreasing the intensity reaching the surface. Results are presented from a nonlinear dynamics analysis of the air-pollution problem, which utilizes time series of O sub(3), carbon monoxide, and SO sub(2). The data for the analysis were obtained from surface-monitoring stations throughout the city. Results are presented for both linear and nonlinear analyses, which suggest a preferred pattern of air transport within the city from the northwest to the southeast along the western edge of the city. The fewer degrees of freedom observed in the center and western sections of the city suggest that the circulations are limited or forced.