The G20 summit of 2016 was held from September 4–5, and a series of stringent emission reduction measures were taken in Hangzhou, an economically developed city in the Yangtze River Delta (YRD), and its surrounding regions. This study analyzed the vertical and regional pollutant distributions and their interactions in Hangzhou during the summit. The results show that the concentration of PM_2.5 decreased and the concentration of ozone increased. The average hourly PM_2.5 concentration decreased by 43.67% during the control period compared with afterward, and PM_2.5 transport was mainly from southern part of Anhui and southeastern part of Zhejiang. There were four occurrences of heavy ozone pollution during the observation period, and the maximum value reached 130.56 ppb. Vertical and horizontal transport mainly occurred at a height of 1–2 km. The Weather Research and Forecasting (WRF-Chem) model demonstrated that the most severe ozone pollution was affected by the northeast wind, and the downdraft created a continuous high concentration of ozone pollution. The correlation between the ozone concentration and the aerosol extinction coefficient was negative below 0.84 km and positive around 0.84–2 km.

2016年G20峰会于9月4-5日召开，长三角经济发达城市杭州及周边地区采取了一系列严厉的减排措施。本研究分析了峰会期间杭州的垂直和区域污染物分布及其相互作用。结果表明，PM _2.5浓度降低，臭氧浓度升高。控制期PM _2.5每小时平均浓度较控制期下降43.67%，PM _2.5运输主要来自安徽南部和浙江东南部。观测期间共发生4次臭氧重度污染，最大值达到130.56 ppb。垂直和水平运输主要发生在1-2公里的高度。Weather Research and Forecasting (WRF-Chem) 模型表明，最严重的臭氧污染受到东北风的影响，下沉气流造成了臭氧污染的持续高浓度。臭氧浓度与气溶胶消光系数之间的相关性在 0.84 km 以下为负相关，在 0.84-2 km 左右为正相关。