Correlation between Ozone and Particulate Matter in the Near-surface Layer of Guangzhou Urban Area, China

A profound understanding of the correlation between ozone and particulate matter is crucial for the collaborative prevention and control of these pollutants. However, existing research predominantly focuses on near-surface analysis, with limited exploration into the vertical variations of the ozone-particulate matter correlation. Leveraging two years of observation data from the Canton Tower Atmospheric Pollution Vertical Gradient Observation Platform, this study investigates the correlation between ozone and particulate matter at different heights in the near-surface layer of Guangzhou urban area. The results indicate that: ①The correlation between ozone and particulate matter is more pronounced in summer and autumn at different heights but diminishes in winter; ②At lower levels, the correlation between ozone and particulate matter is weaker, ascending with altitude, and peaks at higher levels; ③Regardless of the height, the correlation between ozone and particulate matter is positively influenced by smaller particle sizes. In summary, within the near-surface layer below 500 meters in the urban area of Guangzhou, especially under meteorological conditions conducive to ozone generation, a significant positive correlation between ozone and particulate matter is evident. As altitude increases and particle size decreases, the correlation coefficient significantly rises, particularly in high-level ultrafine-sized particles, suggesting shared chemical mechanisms in the formation processes of ozone and particulate matter. This study contributes novel observational evidence supporting the cooperative control principle of ozone and particulate matter.