地闪活动背景下气象条件与O_(3)浓度的相关性研究

Study on the Correlation between Meteorological Conditions and Ozone Concentration under the Background of Ground Lightning Activity

基于2013~2017年重庆北碚区缙云山、蔡家和天生3个环境监测站点日值数据,结合地闪观测数据和相关气象要素资料,采用数理统计方法分析了气象条件与O_(3)浓度的关系,并基于HYSPLIT模型研究了闪电日O_(3)传输路径和潜在源区。结果表明:(1)北碚O_(3)浓度峰值大多出现在7月,低值大多出现在12月,其浓度分布从高到低依次为缙云山、蔡家、天生。(2)对比闪电日与非闪电日大气污染浓度,闪电日NO_(2)、CO平均浓度低于非闪电日,O_(3)则相反,闪电日缙云山O_(3)浓度超标率明显低于蔡家和天生。(3)NO_(2)浓度与地闪频次呈负相关,且天生和蔡家NO_(2)浓度波动大于缙云山,O_(3)浓度与地闪频次呈正相关。(4)夏季闪电日O_(3)气团传输路径主要来自南方。(5)地闪活动发生时O_(3)浓度高于非闪电日,其主要原因是夏季地闪频次较高,电解反应频繁,同时重庆夏季光照时间较长,光化学反应充分,两种反应的叠加效果大于降水清除作用。

Based on the daily data sets of three environmental monitoring stations in Beibei,Chongqing from 2013 to 2017,the relationship between meteorological conditions and ozone concentration was analyzed by mathematical statistics combined with the ground flash observation data and relevant meteorological element data,and the ozone transmission path and potential source area were analyzed based on the hysplit model method.The results show that:(1)The peak value of ozone concentration in Beibei mostly appeared in July,and the low value mostly appeared in December.The ozone concentration distribution from high to low was Jinyun Mountain,Caijia and Tiansheng.(2)Compared with the air pollution concentrations on lightning days and non-lightning days,the average concentrations of NO_(2) and CO on lightning days were lower than those on non-lightning days,while ozone was on the contrary.The over standard rate of ozone concentration on lightning day in Jinyun Mountain was significantly lower than that in the other two places.(3)No_(2) concentration was negatively correlated with lightning frequency,and the fluctuation of NO_(2) concentration in Tiansheng station and Caijia station was greater than that in Jinyun Mountain,and ozone concentration was positively correlated with lightning frequency.(4)The transmission path of ozone air mass in summer lightning days mainly came from the south.(5)The ozone concentration was higher than that on nonlightning days when ground lightning activities occurred,which was mainly due to the high frequency of ground lightning and frequent electrolytic reaction in summer.And because of the long illumination time and sufficient photochemical reaction in summer of Chongqing,the superposition effect of the two reactions was greater than that of precipitation removal.