气象因子和海风对秦皇岛市臭氧污染的影响

The influences of meteorological factors and sea breeze on ozone pollution in Qinhuangdao

利用2017年9月至2019年9月秦皇岛市环境监测站污染物浓度资料以及秦皇岛市国家基本气象站和浮标站的气象数据,统计分析了秦皇岛市O3污染特征以及气象因子和海风对秦皇岛市O3污染的影响。结果表明:秦皇岛市O3污染月变化特征表现为以5-6月和9月最为严重,10-12月和1-2月则无O3超标天气出现。O3污染的日变化特征表现为单峰型分布,午后O3浓度最高而清晨O3浓度最低。有利于秦皇岛市出现O3污染的气象条件为太阳辐射强度850-950 W·m^(-2)、日最高气温高于32℃、无降水和相对湿度50%-60%、受SW和SSW风影响。秦皇岛市海风以6-8月最多,出现频率达50%以上,海风多在上午08-10时开始出现,午后12-15时达到最大,傍晚以后减弱结束;5-6月和8-9月有海风日的O3-8h平均浓度均高于无海风日,且5月、6月和9月有海风日的O3-8h月平均浓度高达155-166μg·m-3,海陆风环流对秦皇岛市的O3污染有加重的影响。

Based on the data of air pollution concentration from Qinhuangdao environmental monitoring station,the meteorological data from Qinhuangdao meteorological observation station and buoy station,the characteristics of O3 pollution and its response to meteorological factors and the sea breeze were researched. Results show that the monthly variation of O3 pollution in Qinhuangdao is characterized by the most serious in May-June and September,and no day with O3 exceeding the standard in October-December and January-February. The diurnal variation of O3 is unimodal distribution i. e. the O3 concentration is highest in the afternoon and lowest in the morning. In general,the key meteorological factors triggering O3 pollution in Qinhuangdao are solar radiation of 850-950 W·m^(-2),daily maximum temperature over 32 ℃,relative humidity of 50%-60%,no precipitation,and SW or SSW wind dominant respectively. The sea breeze in Qinhuangdao is the most common phenomenon from June to August,with a frequency of over 50%. Usually,the sea breeze starts to appear at 8-10 a. m.,reaches its maximum at noon-3 p. m.,and weakens and is over after the evening. The average concentrations of O3-8 h on days with the sea breeze from May to June and August to September are higher than those on days without sea breeze,and the monthly average concentrations of O3-8 h on days with the sea breeze in May,June,and September are as high as 155-166 μg·m-3. All these indicate that the circulation of sea-land breeze plays a role in aggravating O3 pollution in Qinhuangdao.