Analysis of the Sulfur Dioxide Column Concentration over Jing- Jin-Ji, China, Based on Satellite Observations during the Past Decade

Atmospheric sulfur dioxide (SO2) is a major air pollutant and has the most negative effect on atmospheric chemistry. In this study, measurements of SO2 column concentration obtained from an ozone monitoring instrument (OMI) are used to investigate the temporal and spatial dynamics of SO2. Temporal and spatial distributions of SO2 concentrations obtained from OMI over the Beijing-Tianjin-Hebei (Jing-Jin-Ji) region from 2007 to 2016 are presented, and annual changes and trends in the seasonal cycle are shown. The annual variations of SO2 concentration are found to have decreased 47.6% from 2007 to 2016, and the SO2 concentration shows a high correlation with SO2 emissions. SO2 shows significant cyclical seasonal characteristics over Jing-Jin-Ji, with maximum values in winter and minimum in summer; both temperature and precipitation are negatively correlated with SO2 concentrations in seasonal variations. In addition, the spatial distribution is unbalanced, and Shijiazhuang-Xingtai-Handan is found to be in highly polluted areas, which may be related to energy consumption. The overall trends in the average annual value of SO2 in the 13 sites appear to have decreased since 2007, and SO2 concentrations in the Shijiazhuang-Xingtai-Handan region decreased by 55% during the past decade, so the Chinese government has made great efforts in pollution reduction, and has achieved remarkable results.