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

The processes of O 3 source and sink are complicated, and few existing studies focus on Ganzhou City, leading to a limited understanding of O 3 pollution in Ganzhou City or even Jiangxi Province. Here, we investigate the comprehensive formation mechanism of O 3 pollution from the aspects of precursor emission , chemical transformation , meteorological effects and three-dimensional transmission by using the vertical profiles for O 3 concentration and wind information, ground monitoring data of ambient air quality, meteorological and volatile organic compounds (VOCs). The mean concentrations of O 3 , NO 2 and TVOC shows significant growth in the early stage of O 3 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 O 3 formation potential (OFP) concentration in the total OFP concentration did not change significantly before and after O 3 pollution. The frequent high-altitude subsidence of O 3 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 O 3 , which is not conducive to the calculation of O 3 -8H concentration and are important reasons for O 3 exceeding the standard. Meanwhile, the meteorological conditions like wind velocity and temperature may also influence the variations in the O 3 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 O 3 polluted days due to their significant increasing in OFP concentrations.