Common source areas of air pollution vary with haze intensity in the Yangtze River Delta, China

Xue Chen (1) , Shaocai Yu (2, 1) , Liqiang Wang (1) , Zhen Li (1) , Yibo Zhang (1) , Mengying Li (1) , Khalid Mehmood (1) , Weiping Liu (1) , Pengfei Li (3) , Eric Lichtfouse (4) , Daniel Rosenfeld (5) , John Seinfeld (2)

1 Zhejiang University
2 CALTECH - California Institute of Technology
3 Agricultural University of Hebei
4 CEREGE - Centre européen de recherche et d'enseignement des géosciences de l'environnement
5 HUJ - The Hebrew University of Jerusalem

Rapid development of China's industrialization and urbanization in the past decades has highly decreased air quality. For instance, the Yangtze River Delta, a major economic area in China, is incurring strong haze pollution, yet precise pollution sources are unknown. Here, we hypothesized that sources of haze pollution might be the same in nearby cities within the region. To test this hypothesis, we studied sources in four major cities, Hefei, Hangzhou, Nanjing, and Shanghai, during the strong haze period from November 28 to December 10, 2013. This period was divided into four periods according to air PM 2.5 concentrations (PM: particulate matter): slight haze, moderate haze, heavy haze, and severe haze periods. Common pollution source areas were identified for the first time by backward trajectories and concentration weighted trajectory maps of PM 2.5. Results show that all cities contain air masses transported from the northwestern and northeastern regions. Emissions came mainly from northern and central China during the moderate haze period and from adjacent provinces during the severe haze period. During the heavy haze period, common sources were mainly located in the Anhui province, while during the severe haze period, common sources were mainly located in the northeastern part of the Anhui province and the western part of the Jiangsu province. Overall, our findings show that areas of pollution sources vary with the intensity of haze pollution. Our mapping method should thus provide more precise information to control air pollution at the regional scale.

Mots clés: atmosphere; haze; PM2.5; Yangtze River Delta; HYSPLIT; trajectories; CWT; modeling; air pollution; particulate matter

Domaines: Modélisation et simulation; Milieux et Changements globaux; Ingénierie de l'environnement; Interfaces continentales, environnement; Océan, Atmosphère; Climatologie; Météorologie; Santé; Bioclimatologie

Xue Chen, Shaocai Yu, Liqiang Wang, Zhen Li, Yibo Zhang, et al.. Common source areas of air pollution vary with haze intensity in the Yangtze River Delta, China. Environmental Chemistry Letters, 2020, 18, pp.957 - 965. ⟨10.1007/s10311-020-00976-0⟩. ⟨hal-02563173⟩