Journal cover Journal topic
Atmospheric Chemistry and Physics An interactive open-access journal of the European Geosciences Union
Journal topic

Journal metrics

Journal metrics

  • IF value: 5.668 IF 5.668
  • IF 5-year value: 6.201 IF 5-year
    6.201
  • CiteScore value: 6.13 CiteScore
    6.13
  • SNIP value: 1.633 SNIP 1.633
  • IPP value: 5.91 IPP 5.91
  • SJR value: 2.938 SJR 2.938
  • Scimago H <br class='hide-on-tablet hide-on-mobile'>index value: 174 Scimago H
    index 174
  • h5-index value: 87 h5-index 87
Volume 18, issue 6
Atmos. Chem. Phys., 18, 4277-4295, 2018
https://doi.org/10.5194/acp-18-4277-2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.
Atmos. Chem. Phys., 18, 4277-4295, 2018
https://doi.org/10.5194/acp-18-4277-2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.

Research article 28 Mar 2018

Research article | 28 Mar 2018

Ozone pollution around a coastal region of South China Sea: interaction between marine and continental air

Hao Wang1,*, Xiaopu Lyu1,*, Hai Guo1, Yu Wang1, Shichun Zou2, Zhenhao Ling3, Xinming Wang4, Fei Jiang5, Yangzong Zeren1, Wenzhuo Pan1, Xiaobo Huang6, and Jin Shen7 Hao Wang et al.
  • 1Air Quality Studies, Department of Civil and Environmental Engineering, Hong Kong Polytechnic University, Hong Kong, China
  • 2School of Marine Sciences, Sun Yat-sen University, Guangzhou, China
  • 3School of Atmospheric Sciences, Sun Yat-sen University, Guangzhou, China
  • 4Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, China
  • 5International Institute for Earth System Science, Nanjing University, Nanjing, China
  • 6Shenzhen Academy of Environmental Sciences, Shenzhen, China
  • 7State Key Laboratory of Regional Air Quality Monitoring, Guangdong Key Laboratory of Secondary Air Pollution Research, Guangdong Environmental Monitoring Center, Guangzhou, China
  • *These authors contributed equally to this work.

Abstract. Marine atmosphere is usually considered to be a clean environment, but this study indicates that the near-coast waters of the South China Sea (SCS) suffer from even worse air quality than coastal cities. The analyses were based on concurrent field measurements of target air pollutants and meteorological parameters conducted at a suburban site (Tung Chung, TC) and a nearby marine site (Wan Shan, WS) from August to November 2013. The observations showed that the levels of primary air pollutants were significantly lower at WS than those at TC, while the ozone (O3) value was greater at WS. Higher O3 levels at WS were attributed to the weaker NO titration and higher O3 production rate because of stronger oxidative capacity of the atmosphere. However, O3 episodes were concurrently observed at both sites under certain meteorological conditions, such as tropical cyclones, continental anticyclones and sea–land breezes (SLBs). Driven by these synoptic systems and mesoscale recirculations, the interaction between continental and marine air masses profoundly changed the atmospheric composition and subsequently influenced the formation and redistribution of O3 in the coastal areas. When continental air intruded into marine atmosphere, the O3 pollution was magnified over the SCS, and the elevated O3 ( > 100ppbv) could overspread the sea boundary layer  ∼ 8 times the area of Hong Kong. In some cases, the exaggerated O3 pollution over the SCS was recirculated to the coastal inshore by sea breeze, leading to aggravated O3 pollution in coastal cities. The findings are applicable to similar mesoscale environments around the world where the maritime atmosphere is potentially influenced by severe continental air pollution.

Publications Copernicus
Download
Short summary
While oceanic air is generally thought to be clean, the air pollution over waters in proximity to the coasts is not well recognized. This research indicated that ozone was higher over South China Sea (SCS) than that in the adjacent continental area, while continental anticyclone, tropical cyclone and land breeze favored O3 formation over SCS. In addition, weaker NO titration and stronger atmospheric oxidative capacity led to higher O3 production efficiency over SCS.
While oceanic air is generally thought to be clean, the air pollution over waters in proximity...
Citation
Share