TY - JOUR
T1 - Observed trends in ground-level O3 in Monterrey, Mexico, during 1993–2014
T2 - comparison with Mexico City and Guadalajara
AU - Hernandez Paniagua, Ivan
AU - Clemitshaw, Kevin
AU - Mendoza, Alberto
PY - 2017/7/31
Y1 - 2017/7/31
N2 - Here, we present an assessment of long-term trends in O3 and odd oxygen (O3 + NO2) at the industrial Monterrey metropolitan area (MMA) in NE Mexico. Diurnal amplitudes in Ox (AVd) are used as a proxy for net O3 production, which is influenced by the NO2 photolysis rate. No significant differences in the AVd are observed between weekends and weekdays, although the largest AVd values are observed at sites downwind of industrial areas. The highest O3 mixing ratios are observed in spring, with minimum values in winter. The largest annual variations in O3 are typically observed downwind of the MMA, with the lowest variations generally recorded in highly populated areas and close to industrial areas. A wind sector analysis of mixing ratios of O3 precursors revealed that the dominant sources of emissions are located in the industrial regions within the MMA and surrounding area. Significant increasing trends in O3 in spring, summer, and autumn are observed depending on site location, with trends in annual averages ranging between 0.19 and 0.33ppb yr−1. Overall, from 1993 to 2014, within the MMA, O3 has increased at an average rate of 0.22ppb yr−1 (p < 0. 01), which is in marked contrast with the decline of 1.15ppb yr−1(p < 0. 001) observed in the Mexico City metropolitan area (MCMA) for the same period. No clear trend is observed from 1996 to 2014 within the Guadalajara metropolitan area (GMA).
AB - Here, we present an assessment of long-term trends in O3 and odd oxygen (O3 + NO2) at the industrial Monterrey metropolitan area (MMA) in NE Mexico. Diurnal amplitudes in Ox (AVd) are used as a proxy for net O3 production, which is influenced by the NO2 photolysis rate. No significant differences in the AVd are observed between weekends and weekdays, although the largest AVd values are observed at sites downwind of industrial areas. The highest O3 mixing ratios are observed in spring, with minimum values in winter. The largest annual variations in O3 are typically observed downwind of the MMA, with the lowest variations generally recorded in highly populated areas and close to industrial areas. A wind sector analysis of mixing ratios of O3 precursors revealed that the dominant sources of emissions are located in the industrial regions within the MMA and surrounding area. Significant increasing trends in O3 in spring, summer, and autumn are observed depending on site location, with trends in annual averages ranging between 0.19 and 0.33ppb yr−1. Overall, from 1993 to 2014, within the MMA, O3 has increased at an average rate of 0.22ppb yr−1 (p < 0. 01), which is in marked contrast with the decline of 1.15ppb yr−1(p < 0. 001) observed in the Mexico City metropolitan area (MCMA) for the same period. No clear trend is observed from 1996 to 2014 within the Guadalajara metropolitan area (GMA).
U2 - 10.5194/acp-17-9163-2017
DO - 10.5194/acp-17-9163-2017
M3 - Article
SN - 1680-7316
VL - 17
SP - 9163
EP - 9185
JO - Atmospheric Chemistry and Physics
JF - Atmospheric Chemistry and Physics
IS - 14
ER -