佛山市一次持续性O_(3)污染过程特征分析及来源解析

Characteristics and source apportionment of a persistent O_(3) episode in Foshan

2019年9月15日至10月2日,佛山市发生了长达18 d的O_(3)持续性污染过程,结合监测数据和数值模拟两种方法,分析佛山市O_(3)污染过程特征和量化污染来源。结果表明:(1)副热带高压、台风外围天气系统及两者叠加型诱发这次长时间的O_(3)污染,副热带高压强盛是造成这次长时间污染的主要原因。(2)当温度>30℃、相对湿度≤50%、风力在3级以下、风向为偏北风时,O_(3)易出现超标。(3)珠江三角洲城市中位于污染上风向的广州市对佛山市O_(3)污染平均贡献率(26.9%)明显大于佛山市本地贡献率(14.4%)。道路移动源对佛山市本地生成的O_(3)污染平均贡献率(41.5%)最大。

A continuous O_(3)pollution process occurred in Foshan for 18 days from September 15 to October 2,2019.Combined with monitoring data and numerical simulation methods,the characteristics of O_(3)pollution process in Foshan were analyzed and the pollution sources were quantified.The results showed that:(1)this long time O_(3)pollution was affected by the subtropical high,typhoon periphery synoptic systems and their superposition type.The strong subtropical high was the main reason.(2)When the temperature was more than 30℃,the relative humidity was less than 50%,the wind was below grade 3 and the wind direction was northerly,O_(3)was easy to exceed the standard.(3)In the Pearl River Delta cities,Guangzhou,which was located in the upwind direction of pollution,contributes 26.9%to O_(3)pollution in Foshan,which was significantly higher than Foshan’s local contribution(14.4%).The average contribution rate(41.5%)of road mobile sources to the local O_(3)pollution in Foshan was the largest.