2015-2019年南阳市臭氧污染特征及气象因素影响

Analysis of ozone pollution characteristics and meteorological parameters in Nanyang City from 2015 to 2019

基于2015—2019年南阳市5个国控空气质量监测站点常规污染六参数逐时观测资料,结合国家基准站南阳站地面气象要素数据,识别南阳市O_(3)污染的时空分布特征及气象因素影响。结果表明:2015—2019年南阳市O_(3)污染日趋严重,O_(3)日最大8 h滑动浓度平均值(MDA8)从2015年的145μg/m^(3)增至2019年的181μg/m^(3),增幅超过25%;O_(3)污染呈显著季节性差异,峰值出现在夏季;从空间分布来看,O_(3)污染呈现明显的块状分布特征,其高值出现在城区中部区域;气象要素是影响南阳市O_(3)浓度的重要因子,高温、低湿和高能见度条件下易出现O_(3)污染,且随着风速的增加,O_(3)浓度表现出先升后降的趋势。2019年6月,南阳市O_(3)污染严重,超标频率为63%,期间共经历3次O_(3)污染过程,污染事件与不利的气象条件和强污染排放强度有关。

Based on the hourly observation data of six conventional pollution parameters provided by five state-controlled environmental monitoring sites in Nanyang City from 2015 to 2019,and combined with the surface meteorological elements data of Nanyang Station,the national benchmark station,the temporal and spatial distribution characteristics of ozone pollution and the influence of meteorological factors were investigated.The results showed that the ozone pollution in Nanyang City became serious from 2015 to 2019,and the average daily maximum 8 h sliding concentration(MDA8)of O_(3) increased from 145μg/m^(3) in 2015 to 181μg/m^(3) in 2019,with an increase of more than 25%.O_(3) pollution displayed a distinct seasonality,where the maximum values occurred in summer.As for spatial distribution,the O_(3) pollution presented obvious block distribution characteristics,and its high value appeared in the central area of the city.Meteorological conditions were important factors affecting the concentration of O_(3) in Nanyang City.Under high temperature,low humidity and high visibility conditions,it was easy to form serious ozone pollution.With the increase of wind speed,the O_(3) concentration increased first and then decreased.In June 2019,the O_(3) pollution in Nanyang City was serious,and the O_(3) exceedance rate was more than 63%.During this period,there were three ozone pollution processes.The pollution events were related to favorable meteorological conditions and strong pollution emission intensity.