A case study of air quality control in Beijing and the surrounding area during the 2015 World Championships and Parade

Abstract

Based on satellite observations, the effects of emission reduction measures on air pollutants (NO2 (nitrogen dioxide), SO2 (sulfur dioxide), and aerosols) were estimated in Beijing and its surroundings during the 2015 World Championships and Parade (WCP) held in Beijing. Compared with the same period in the previous three years (2012–2014), the tropospheric vertical column densities of NO2 and SO2 in 2015 were significantly reduced in Beijing and its surroundings. During the WCP, aerosol optical depth was reduced most significantly in Beijing, while NO2 and SO2 were reduced most significantly in Hebei and Tianjin, respectively. The meteorological conditions were also favorable during this period. During the WCP, the North China Plain was located under high pressure from the north of China. A southward pressure gradient force and weak northerly and northeasterly winds blocked the transport of pollution from southern and western parts of the industrial area (Hebei, Shanxi and Shandong provinces). Cold air masses pushed southwards weakly. These conditions were beneficial to the removal of air pollutants in Beijing.

Keywords

• Parade
• air quality
• satellite observation
• emission control
• meteorological factor