Ozone plays a crucial role in shaping atmospheric environments, and understanding its vertical distribution is essential for deciphering its formation and transport mechanisms. This study integrates ozone lidar observations, WRF-Chem modeling, and meteorological analyses to investigate the monthly and diurnal variations of ozone vertical profiles and its generation and transport mechanisms during a heatwave from July to September 2022 in Guangzhou. Results show that ozone concentrations were primarily confined below 2 km, with significantly higher levels in July compared to August and September, reaching a maximum of 420 μg m−3. WRF-Chem modeling identified photochemical reactions as the dominant driver of ozone formation, with average contributions of 5.9 ppb hr−1, 6.3 ppb hr−1, and 3.7 ppb hr−1 in July, August, and September, respectively. Vertical mixing and convective processes had minimal influence, while advective accumulation became increasingly significant with altitude. Meteorological analyses further indicated that the high temperature and low humidity caused by the subtropical high pressure system further intensified photochemical reactions and promoted ozone production. In addition, the south-westerly winds at the periphery of anticyclone drove ozone transport to downstream areas such as Fujian. This study advances our understanding of ozone vertical profiles and transport dynamics, providing critical insights for developing effective ozone pollution control strategies in the Pearl River Delta region.

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