The effectiveness of emission control policies in regulating air pollution over coastal ports of China: Spatiotemporal variations of NO2 and SO2

Air pollution over coastal port areas has become a major concern of today's world. As one the largest shipping countries, China issued series emission control policies to regulate air in these areas. This study investigated effectiveness by exploring spatiotemporal variations NO2 and SO2 five clusters i.e., Bohai Rim Area (BRA), Yangtze River Delta (YRD), Pearl (PRD), Southeast Coast (SEC) Southwest (SWC) from 2005 2020 using tropospheric planetary boundary layer Vertical Column Densities (VCDs) retrieved Ozone Monitoring Instrument (OMI). The levels were found be highest around 2011, whereas showed decreasing trends after 2007, with rebounds 2011. BRA exhibited average level compared other clusters. PRD implemented earlier than clusters, YRD have controlled more effectively during 2010–2020. SWC saw an increase 2015–2020. for individual ports, Guangzhou been most entire period; Qinhuangdao, Tangshan, Tianjin, Lianyungang, Qingdao Rizhao made great strides reducing However, Beibu Gulf Haikou clear increases 2018–2020 which may attributed strong growth cargo throughput. Findings this can potentially help different authorities evaluate their actions support future decision making.