西昌市臭氧污染特征及影响因素分析

Analysis on Ozone Pollution Characteristics and Influencing Factors in Xichang City

根据西昌市环境空气自动站监测数据,分析了西昌市O_3现状、时空变化特征和污染日特征,探讨了O_3与其前体物及气象因素的关系。结果表明,西昌市O_3浓度春夏季高、秋冬季低,伴有明显的春、夏季双峰。O_3日变化为最低值出现在早晨8～9点,峰值出现在14至17时,夜间浓度缓慢下降,污染日峰值持续时间延长,出现夜间高值,最高值达为165μg/m^3。空间分布特征表现为生活区的市政府、州政府浓度最高,其次是郊区的青龙寺,位于商业区的长安点位O_3浓度相对最低。O_3与其前体物NO_X、NO_2及NO小时浓度呈负相关性。O_3与气压、相对湿度呈负相关,与气温、风速呈正相关。

According to the ambient air monitoring data from local monitoring stations, this paper analyzed the current situation, the spatial and temporal change characteristics of ozone pollution, , and discussed the relationships between the meteorological conditions and the ozone and its precursors concentrations in Xiehang City. The results showed that ozone concentrations in spring and summer were higher than that in autumn and winter with obvious double peak in spring and summer. The ozone concentration usually peaked at 14 ： 00 to 17 ： 00, and dropped to the valley at 8 ： 00 to 9 ： 00. In the peak days, the ozone concentration at night decreased slowly, with longer peak time and higher concentration at night. And the highest value was 165μg/m3. The spatial distribution characteristics showed that the highest ozone concentration occurred in the city government and the state government area, followed by the Qinglong temple area, and the commercial area Chang＇ an. There was a significant negative relationship between hourly average concentration of ozone and the concentrations of the precursors NOx, NO2 , NO. It also showed a positive relationship between the concentration of ozone and atmospheric temperature and wind speed, and a negative relationship with atmospheric pressure and relative humidity.