2015-2019年广西近地面大气臭氧污染特征分析

Analysis of Characteristics of Near-surface Atmospheric Ozone Pollution in Guangxi from 2015 to 2019

为了解广西臭氧(O_(3))污染形成条件及来源,通过分析2015-2019年44个广西城市环境空气自动监测站点的近地面臭氧观测数据及城市气象数据,并结合2019年9月华南区域278个自动监测站点的O_(3)监测数据,探讨广西近地面O_(3)的污染特征及其与气象要素的关系。结果表明:近5年来广西O_(3)质量浓度逐年增加,平均增长率为2.64μg/(m^(3)·a),春秋季增长较快;广西全年均会出现O_(3)超标现象,O_(3)日超标率逐年增长,各城市间差异逐年减小,广西南部沿海城市日超标率总体高于其他城市;O_(3)污染易发生于气温高于10℃、湿度在40%-70%的环境区域;广西区域O_(3)特征有6个主成分,第1主成分即可解释64.58%的O_(3)质量浓度;区域臭氧传输对广西高浓度臭氧污染事件有重大贡献,其中低浓度臭氧污染主要为本地生成。

In order to understand the formation conditions and sources of ozone(O_(3))pollution in Guangxi,the pollution characteristics of near-surface ozone in Guangxi and its relationship with meteorological factors were discussed by analyzing the near-surface ozone observation data and urban meteorological data of 44 automatic monitoring stations of ambient air in Guangxi from 2015 to 2019,and combining with the ozone monitoring data of 278 automatic monitoring stations in South China region in September 2019.The results showed that over the past five years,the ozone concentration in Guangxi had increased year by year,with an average growth rate of 2.64μg/(m^(3)·a),and with a faster growth in spring and autumn.The ozone exceeded the standard all year round in Guangxi.The daily ozone exceeding rate increased year by year,and the difference among cities decreased.The daily ozone exceeding rate of coastal cities in southern Guangxi was generally higher than that of other cities.The ozone pollution was likely to occur in environmental areas where the temperature was higher than 10℃and the humidity was between 40% and 70%.There were 6 principal components in the characteristics of O_(3) in Guangxi and 64.58% of the ozone concentration was explained by the first principal component.Regional ozone transmission had made a significant contribution to the high-concentration ozone pollution incident in Guangxi,and the low-ozone pollution was strongly affected by local generation.