2022年广州市一次夏季臭氧污染过程成因分析

Cause Analysis of A Summer Ozone Pollution Process in Guangzhou in 2022

为探究持续减排背景下广州市夏季臭氧(O_(3))污染成因,选取2022年夏季首次O_(3)污染过程进行研究。文章结合O_(3)及其前体物观测数据、气象观测数据,从气象条件、区域传输和O_(3)前体物排放等方面较为全面地分析了此次污染过程的特征及传输对O_(3)的影响。结果表明,观测期间受副高控制,低湿高温有利于O_(3)生成,小风时数增多,污染扩散条件差,日照时数加长,有利于光化学反应。污染天主导风向为南风,本轮污染过程由南向北推进,O_(3)小时变化出现双峰拖尾峰现象,存在一定区域污染和传输影响。污染前一晚及当日凌晨,NO_(2)浓度和挥发性有机物均偏高,为O_(3)生成提供了充分条件。

In order to explore the causes of summer ozone(O_(3))pollution in Guangzhou under the background of continuous emission reduction,the f irst ozone pollution process in the summer of 2022 was selected to study.Based on the observation data of ozone and its precursors and meteorological data,the characteristics of the pollution process and the inf luence of transmission on O_(3) were comprehensively analyzed from the aspects of meteorological conditions,regional transmission and emission of ozone precursors.The results show that under the control of subtropical high,low humidity and high temperature are conducive to ozone generation,low wind hours,poor pollution diffusion conditions,and longer sunshine hours,which are conducive to photochemical reaction.The dominant wind direction of the pollution day was south wind,and the current round of pollution process advanced from south to north,and the hourly variation of ozone appeared a double-peak trailing peak phenomenon,which had certain regional pollution and transmission effects.The night before the pollution and the early morning of the same day,the concentration of NO_(2) and volatile organic compounds were high,providing suff icient conditions for ozone generation.