Evolution and Assessment of the Atmospheric Composition in Hangzhou and its Surrounding Areas during the G20 Summit

Kai Wu ； Ping Kang ； Xin Tie ； Shan Gu ； Xiaoling Zhang ； Xiaohang Wen ； Lingkai Kong ； Sihui Wang ； Yuzi Chen ； Weihao Pan ； Zhanshan Wang

《Aerosol and Air Quality Research》 19卷12期 (2019/12) Pp. 2757-2769+ap1-9

https://doi.org/10.4209/aaqr.2018.12.0481

摘要

To evaluate the effectiveness of control strategies during the G20 Summit (August 24-September 6, 2016), five sites were selected for investigating the variation in air pollution in the city of Hangzhou and its surrounding areas. The results showed that the air quality in Hangzhou greatly improved after the implementation of strict emission controls. Compared to the same dates from the five preceding years, the G20 period exhibited low relative humidity during the early stage (August 27-31) and no significant differences in other meteorological conditions. The SO_2, NO_2, PM_(10), and PM_(2.5) concentrations averaged across the five sites in Hangzhou decreased by 42.6%, 57.1%, 36%, and 38.5%, respectively, although the average O_3 concentration increased by 19%. These changes indicate that the emission reduction measures decreased the concentrations of several pollutants. Compared to the same dates from the previous year (August 24-September 6, 2015), the G20 period exhibited significantly decreased concentrations for most of the chemical components of PM_(2.5), particularly SO_4^(2-), NO_3^-, and NH_4^+. Additionally, the aerosol optical depth (AOD) and the NO_2 column densities were found to exhibit similar trends with that of the pollutants in this city.

關鍵字

Air quality ； Emission reduction ； G20 Summit ； Ozone sensitivity