Evolution, Transport Characteristics, and Potential Source Regions of PM2.5 and O3 Pollution in a Coastal City of China during 2015–2020

Atmosphere

Bingcheng Wan¹  Min Lv²  Anyong Hu²  Jun Chen³ 

[1] Nanjing Atmospheric Environment and Green Development Research Institute, Nanjing 210044, China;School of Geographic Sciences, Nantong University, Nantong 226019, China;Shanghai Aerospace Electronic Technology Institute, Shanghai 201100, China;

关键词: PM_2.5;    O₃;    evolution;    backward trajectory;    transport pathway;    potential source region;   

DOI  :  10.3390/atmos12101282

来源: DOAJ

【 摘 要 】

The evolution, transport characteristics, and potential source regions of PM_2.5 and O₃ were investigated from 1 January 2015 to 31 December 2020 in the coastal city of Nantong. The annual mean PM_2.5 concentration declined obviously over the entire study period, and was 34.7 μg/m³ in 2020. O₃ had a relatively smooth decreasing trend, but rebounded greatly during 2017 when the most frequent extreme high-temperature events occurred. Similar trends were observed for PM_2.5 and O₃ polluted hours. No PM_2.5-O₃ complex air pollution happened in 2019 and 2020, likely suggesting the preliminary results from the implementation of emission controls. Notable differences in transport pathways and frequencies were observed from the backward trajectory clusters in four seasons in Nantong. Clusters with the largest percentage of polluted PM_2.5 and O₃ trajectories were transported mostly over short distances rather than long distances. Analysis involving the potential source contribution function (PSCF) and concentration weighted trajectory (CWT) showed that PM_2.5 polluted sources were from the adjacent western and northwestern provinces, whereas the influence of eastern marine sources was relatively small. O₃ had a greatly different spatial distribution of polluted source regions from PM_2.5, mostly covering the North China Plain, the Bohai Sea, and the Yellow Sea.

【 授权许可】

Unknown