2019年佛山臭氧污染及污染气象条件变化

The Changes of Ozone Pollution and Polluted Meteorological Conditions of Foshan Area in 2019

利用佛山污染物浓度和气象要素观测数据,文章对比分析了2018年和2019年佛山地区全年空气质量和污染气象条件状况,并对2019年臭氧(O3)污染现状及其与气象要素的关系进行了研究。结果表明:(1)2019年佛山空气质量以优良为主,空气质量指数(AQI)达标率为78.9%,较2018年(89.0%)下降了7.4个百分点,主要的首要污染物为O3-8h(49.2%)、NO2(33.7%)、PM10(14.0%)和PM2.5(3.0%),O3和NO2污染较颗粒物污染愈发严重和突出;(2)污染气象条件来看,2019年干季(1月、11至12月)佛山降雨量和降水日数明显偏少,湿清除条件较2018年同期转差;2019年O3高发时段(8-11月)日照时数和高温日数均明显偏多(59%,5.6d),O3污染气象条件转差;(3)2019年佛山共发生10次连续3d或以上的O3污染过程,最长持续18 d(9月15日-10月2日);台风外围形势、副高控制形势、冷锋前形势和均压场4种天气形势是造成2019年佛山地区O3连续污染过程的主要天气形势;(4)2019年佛山O3浓度与日照时数呈正相关;与相对湿度呈负相关,当相对湿度>75%时,随相对湿度增高,O3浓度迅速降低;与最高气温基本呈正相关;当风力为3 m/s以上且吹偏西和西北气流时,O3浓度出现高值,佛山西北和偏西地区可能存在O3污染源区。

This article comparatively analyzed the air quality and meteorological pollution conditions of Foshan area in 2018 and 2019,and discussed the ozone(03)pollution and its relationship with meteorological elements in 2019 by using the observational data of pollutant concentrations and meteorological elements.The results show that:(1)The air quality of Foshan in2019 was mainly dominated by extremely or well clean,the air quality index(AQI)compliance rate was 78.9%,decreased by7.4 percentage points compared to that in 2018(89.0%),the main primary pollutants were O3-8 h(49.2%),NO2(33.7%),PM10(14.0%)and PM2.5(3.0%),the pollution of O3 and NO2 were becoming more serious and prominent than particulate pollution.(2)From the perspective of meteorological pollution conditions,the rainfalls and precipitation days of Foshan in 2019 were significantly less than those in 2018 during the dry season(January,November to December),the wet removal conditions were worsened compared to the same period in 2018;markedly more sunshine hours and high temperature days(59%,5.6 days)were observed during high incidence period of O3 pollution(August to November)in 2019,the meteorological conditions of O3 pollution was deteriorated.(3)There were 10 O3 continuous pollution processes(with a duration up to three consecutive days or more)occurred in Foshan during the year of 2019,the longest process lasted for 18 days(September 15 to October 2);typhoon peripheral,deputy high control,cold front and equalizing field were the main four weather situations caused O3 continuous pollution processes in Foshan area during 2019.(4)The O3 concentration of Foshan in 2019 was positively correlated with the sunshine hour,and negatively correlated with relative humidity;when the relative humidity was greater than 75%,the O3 concentration was rapidly decreased as the relative humidity increased;the O3 concentration was basically positively correlated with the maximum temperature;when the wind speed was higher than 3 m/s with a wind direction of west or northwest,high O3 concentrations were observed,suggesting an ozone contribution source from the northwest and west of Foshan.