title: Ambient Ozone Control in a Photochemically Active Region: Short-Term Despiking or Long-Term Attainment?
abstract: China has made significant progress decreasing the ambient concentrations of most air pollutants, but ozone (O3) is an exception. O3 mixing ratios during pollution episodes are far higher than the national standard in the Pearl River Delta (PRD), thus greater evidence-based control efforts are needed for O3 attainment. By using a validated O3 modeling system and the latest regional emission inventory, this study illustrates that control strategies for short-term O3 despiking and long-term attainment in the PRD may be contradictory. VOC-focused controls are more efficient for O3 despiking in urban and industrial areas, but significant NOx emission reductions and a subsequent transition to a NOx-limited regime are required for O3 attainment. By tracking O3 changes along the entire path toward long-term attainment, this study recommends to put a greater focus on NOx emission controls region-wide. Parallel VOC reductions around the Nansha port are necessary in summertime and should be extended to the urban and industrial areas in fall with a flexibility to be strengthened on days forecasted to have elevated O3. Contingent VOC-focused controls on top of regular NOx-focused controls would lay the groundwork for striking a balance between short-term despiking and long-term attainment of O3 concentrations in the PRD.
authors.affiliation: School of Environment and Energy, South China University of Technology , Guangzhou 510006, China.
authors.forename: Jiamin
authors.initials: J
authors.lastname: Ou
authors.affiliation: School of Environment and Energy, South China University of Technology , Guangzhou 510006, China.
authors.forename: Zibing
authors.initials: Z
authors.lastname: Yuan
authors.affiliation: School of Environment and Energy, South China University of Technology , Guangzhou 510006, China.
authors.forename: Junyu
authors.initials: J
authors.lastname: Zheng
authors.affiliation: School of Environment and Energy, South China University of Technology , Guangzhou 510006, China.
authors.forename: Zhijiong
authors.initials: Z
authors.lastname: Huang
authors.affiliation: State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University , Beijing 100871, China.
authors.forename: Min
authors.initials: M
authors.lastname: Shao
authors.affiliation: School of Environment and Energy, South China University of Technology , Guangzhou 510006, China.
authors.forename: Zekun
authors.initials: Z
authors.lastname: Li
authors.affiliation: School of Environment and Energy, South China University of Technology , Guangzhou 510006, China.
authors.forename: Xiaobo
authors.initials: X
authors.lastname: Huang
authors.affiliation: Department of Civil and Environmental Engineering, Hong Kong Polytechnic University , Hung Hom, Hong Kong, China.
authors.forename: Hai
authors.initials: H
authors.lastname: Guo
authors.affiliation: Hong Kong Environmental Protection Department, Revenue Tower, 5 Gloucester Road, Wanchai, Hong Kong, China.
authors.forename: Peter K K
authors.initials: PK
authors.lastname: Louie
mesh_terms: D000393:Air Pollutants; D008962:Models, Theoretical; D010126:Ozone; D045483:Rivers; D012621:Seasons
chemical_list: D000393:Air Pollutants; D010126:Ozone