临沂市一次臭氧污染事件的光化学特征及气象要素分析

Analysis of Photochemical Characteristics and Meteorological Elements of an Ozone Pollution Event in Linyi City

随着我国工业发展和机动车保有量增多,臭氧污染逐渐显现,成为大气污染的重要因素。高浓度臭氧威胁生态环境和人体健康并加剧大气污染,因此,臭氧污染防治刻不容缓。本文选取临沂市2022年9月一次臭氧和PM_(2.5)均较高的污染过程,分析近地面污染物浓度、光化学参量和气象要素的变化特征,探究臭氧浓度的影响因素。结果发现,此次过程中臭氧和PM_(2.5)浓度均呈现先升高后回落变化趋势,二者总体走势较为同步,均在9月6日达到最大值(O_(3)-8 h为231.6μg/m^(3),PM_(2.5)为64.8μg/m^(3));光化学特征参量在此次臭氧污染过程中发挥着重要作用,臭氧光化学生成与分解反应速率的相对变化对臭氧浓度有很大影响,臭氧光化学生成潜势峰值变化与臭氧峰值有良好的对应关系;气象要素中,气温对臭氧影响最大,风速与臭氧浓度正相关,而相对湿度与风向对臭氧浓度影响较小。

With the development of industry and the increase in the motor vehicle ownership in China,ozone pollution has gradually emerged and become an important factor in air pollution.High concentrations of ozone can not only threat the ecological environment and human health,but also exacerbate air pollution.Therefore,the prevention and control of ozone pollution is a brook no delay problem.This article selects a pollution process in Linyi City that had high levels of ozone and PM_(2.5) in September 2022,analyzes the characteristics of near-surface pollutant concentrations,photochemical parameters,and meteorological factors,and explores the influencing factors of ozone concentration.The results show that both ozone and PM_(2.5) concentrations rose up first and then decreased during this process,reaching their maximum values on September 6th(O_(3)-8 h was 231.6μg/m^(3),PM_(2.5) was 64.8μg/m^(3)),and the overall trends of them were relatively synchronous.The photochemical characteristic parameters played an important role in the process of ozone pollution.The relative change between the photolysis rate of ozone photochemical generation and decomposition reactions had a significant impact on ozone concentration,and there was a good corresponding relationship between the peak change of ozone photochemical generation potential and ozone peak.Among meteorological factors,temperature has the greatest impact on ozone,with wind speed positively correlated with ozone concentration,while relative humidity and wind direction had smaller impacts on ozone concentration.