Long-term variations in submicron aerosol pollution in 2003–2015 in the atmosphere over Beijing

The optical measurements of submicron aerosol and black carbon (BC) surface concentrations during the falls of 2003– 2015 in Beijing are illustrated. The specific features of long-term variations in these impurities are discussed. The 2003, 2004, 2007, 2010 and 2013-2015 observations were performed simultaneously at the background regional station Xing Long and in the city. The results of comparison between data obtained in Beijing and at the background station showed that, in Beijing, during the falls of 2003—2015, the urban sources of anthropogenic emissions mainly contributed to the BC components, and these emissions decreased by a factor of three over these years. Such a decrease was due to a reduction of the urban primary emissions of submicron aerosol. A significant contribution to the total concentration of submicron aerosol in the city was made by a regional additive, whose value depends on meteorological conditions and anthropogenic activity in the sector located to the south of Beijing at a distance of 100 – 500 km from the capital of China. This additive exceeds the monthly mean concentrations of submicron aerosol from urban sources due to regular smog episodes in the atmosphere over Beijing.