CO2 concentrations in the highly polluted atmosphere of Mexico City

Resumen

Measurements of CO2 concentrations in the atmosphere of Mexico City were carried out through the years 1981-1982, during daylight hours. The results indicate that 82 of the CO2 levels were above 330 ppmv, which is the reported approximate atmospheric background. During daylight hours CO2 concentrations show three maxima: the first between 9:30 and 10:30 h, the second between 12:00 h and 13:00 and the third between 15:00 and 16:00 h local time. The peaks coincide with the rush hours in the city. The annual curves of CO2 show a seasonal variation with low values during the winter and a maximum in spring, the lowest values corresponding to the middle of the rainy season. Since natural sources during the daylight hours are probably negligible, the applicability of CO2 data as an indicator of air pollution in Mexico seems to be feasible.