Ship emissions significantly impact coastal air quality,with the Yangtze River Delta(YRD)region accounting for approximately 50%of China's total shipping emissions.Using the Community Multiscale Air Quality(CMAQ)m...Ship emissions significantly impact coastal air quality,with the Yangtze River Delta(YRD)region accounting for approximately 50%of China's total shipping emissions.Using the Community Multiscale Air Quality(CMAQ)model and process analysis(PA)tool,we quantitatively assessed how atmospheric processes(emissions,chemical reactions,transport,and deposition)contribute to PM2.5and O3,and the chemical pathways of O3formation due to ship emissions.Ship emissions significantly enhanced PM2.5concentrations(>5μg/m3)in the coastal areas of Jiangsu province and offshore regions,with diminishing inland effects.Ship-induced NO3-showed greater inland penetration compared to SO42-,which remained near the coast.In coastal cities,aerosol processes,rather than primary emissions,dominated PM2.5formation,highlighting the importance of secondary formation.O3responses varied spatially,showing coastal titration zones but inland enhancements.Process analysis revealed that vertical transport dominated O3distribution in coastal regions(5-10 ppb),whereas chemical processes showed strong negative contributions(below-10 ppb)along shipping routes.The impact exhibited pronounced diurnal variations,peaking during afternoon hours(14:00-17:00 local standard time(LST),up to 10 ppb/h)with morning titration effects(up to-7.5 ppb/h at 08:00 LST).The vertical profile analysis of shipping-related O3showed surface-level O3titration from ship NOxemissions,with impacts extending to higher layers through vertical mixing.Integrated reaction rate analysis revealed that effective O3control in shipping-influenced regions requires coordinated reduction of both NOxand VOCs.These findings provide insights for developing targeted control strategies,particularly for addressing the complex NOx-O3chemistry and secondary PM2.5formation.展开更多
基金supported by the National Key Research and Development Program of China(No.2022YFC3700703)。
摘要Ship emissions significantly impact coastal air quality,with the Yangtze River Delta(YRD)region accounting for approximately 50%of China's total shipping emissions.Using the Community Multiscale Air Quality(CMAQ)model and process analysis(PA)tool,we quantitatively assessed how atmospheric processes(emissions,chemical reactions,transport,and deposition)contribute to PM2.5and O3,and the chemical pathways of O3formation due to ship emissions.Ship emissions significantly enhanced PM2.5concentrations(>5μg/m3)in the coastal areas of Jiangsu province and offshore regions,with diminishing inland effects.Ship-induced NO3-showed greater inland penetration compared to SO42-,which remained near the coast.In coastal cities,aerosol processes,rather than primary emissions,dominated PM2.5formation,highlighting the importance of secondary formation.O3responses varied spatially,showing coastal titration zones but inland enhancements.Process analysis revealed that vertical transport dominated O3distribution in coastal regions(5-10 ppb),whereas chemical processes showed strong negative contributions(below-10 ppb)along shipping routes.The impact exhibited pronounced diurnal variations,peaking during afternoon hours(14:00-17:00 local standard time(LST),up to 10 ppb/h)with morning titration effects(up to-7.5 ppb/h at 08:00 LST).The vertical profile analysis of shipping-related O3showed surface-level O3titration from ship NOxemissions,with impacts extending to higher layers through vertical mixing.Integrated reaction rate analysis revealed that effective O3control in shipping-influenced regions requires coordinated reduction of both NOxand VOCs.These findings provide insights for developing targeted control strategies,particularly for addressing the complex NOx-O3chemistry and secondary PM2.5formation.