Comprehensive stereo monitoring and traceability analysis of ozone pollution: A case study of a continuous pollution process in Ganzhou City

Abstract

Abstract The processes of O3 source and sink are complicated, and few existing studies focus on Ganzhou City, leading to a limited understanding of O3 pollution in Ganzhou City or even Jiangxi Province. Here, we investigate the comprehensive formation mechanism of O3 pollution from the aspects of precursor emission, chemical transformation, meteorological effects and three-dimensional transmission by using the vertical profiles for O3 concentration and wind information, ground monitoring data of ambient air quality, meteorological and volatile organic compounds (VOCs). The mean concentrations of O3, NO2 and TVOC shows significant growth in the early stage of O3 pollution, while the VOCs components is basically the same and the concentration proportion of the average VOCs concentration in TVOC and the proportion of the average O3 formation potential (OFP) concentration in the total OFP concentration did not change significantly before and after O3 pollution. The frequent high-altitude subsidence of O3 air mass, the night-time residue and the superposition of large-area transmission result in the characteristics of multi-peak and flat-headed peaks on the daily variation curve of O3, which is not conducive to the calculation of O3-8H concentration and are important reasons for O3 exceeding the standard. Meanwhile, the meteorological conditions like wind velocity and temperature may also influence the variations in the O3 concentration. From the point of view of air pollution prevention, the industrial enterprises and mobile sources may still be the vital industry of VOCs supervision and propional, 1-pentene, m-/p-xylene and isoprene could be considered as the important species under emergency management on O3 polluted days due to their significant increasing in OFP concentrations.