Research on the time and space Changing Trend of Air Pollutants in Beijing from 2014 to 2023

Abstract According to the concentration data of PM2.5, PM₁₀, SO₂, NO₂, O₃, CO recorded at 35 monitoring stations in Beijing from January 1, 2014 to June 30, 2023, we analyzed the average annual and seasonal concentrations of air pollutants during this period, and investigated their temporal and spatial trends and possible influencing factors. Furthermore, we use Pearson correlation coefficient to study the relationship between these pollutants. The results show that the concentrations of PM2.5 and PM₁₀ decreased significantly during 2014 to 2022, but increased in 2023, while the concentrations of SO₂, NO₂ and CO decreased steadily, but the concentration of O₃ increased slightly. The average annual concentrations of PM2.5, PM₁₀ and SO₂ were low in summer and autumn, high in spring and winter, the average annual concentration of NO₂ is lowest in autumn, highest in winter, while the seasonal change of O₃ is very significant, its is higher in summer and autumn, lowest in winter. The average annual concentrations of PM2.5, PM₁₀ and NO₂ in the central, southeast and southwest were significantly different from those in the northwest and northeast, with the former higher than the latter. The regional difference of SO₂ and CO from 2014 to 2017 were the same as above, but the difference was not obvious after 2017. Throughout this period, the regional differences in the average annual concentration of O₃ were always not obvious. There is a strong positive correlation among PM2.5, PM₁₀, SO₂, NO₂ and CO, while the correlation between O₃ and these five pollutants is weak or negative.