Impacts of lake–land breezes on the diurnal cycle of ozone in Suzhou

Integrating intensive field observations from August 2024 with high-resolution WRF-Chem simulations, we investigate how Taihu LLB circulations reshape the diurnal O3 profile in Suzhou. We find that a persistent lake-to-land O3 gradient forms in the morning, where the observed urban O3 growth rate notably outpaces box-model photochemical estimates, indicating strong transport contributions. Conversely, in the afternoon, LLB-triggered precipitation causes a sharp O3 reduction through clean-air downdrafts and suppressed photochemistry, collectively driving a unique bimodal diurnal pattern.