佛山市PM_(2.5)污染特征及诱发其高污染过程天气系统分析

Analysis on Pollution Properties of PM_(2.5) in Foshan City and the Inducing Weather Systems

利用2013年佛山市8个国控大气自动监测站点ρ(PM_(2.5))监测数据,分析佛山市PM_(2.5)污染的时空分布特征,并诊断诱发PM_(2.5)高污染过程的关键天气类型。结果表明,佛山市2013年PM_(2.5)年均值为53μg/m3,高于国家二级标准,污染主要集中在三水区中部、南海区中部和禅城区北部。佛山市ρ(PM_(2.5))表现出明显的季节变化和日变化特征,秋、冬季是PM_(2.5)的高污染季节,其值夜间略高于白天,呈典型的双峰型分布,08:00—09:00短暂出现一个浓度的小峰值,推测与上班交通高峰有关。对PM_(2.5)持续高污染发生的地面天气形势分析表明,高压出海是诱发佛山市PM_(2.5)高污染事件最主要的天气类型。

Based on the concentrations of ρ（ PM2.5） automatically measured at the 8 national air quality automatic measuring sites,the properties of PM2.5 spatial and temporal distributions were analyzed,and the key weather systems inducing the high PM2.5 episodes were diagnosed. The results showed that the annual average concentration of PM2.5was high,which was 53 μg/m～3,exceeding the second grade limit of the national standards. The obvious pollution zone of ρ（ PM2.5） was in the middle of Sanshui,the middle of Nanhai and the north of Chancheng. The varies of PM2.5in Foshan show distinct seasonal and diurnal variation.Episodes usually happened in autumn and winter,while the concentration at night usually higher than that in daytime. A remarkable concentration peak was observed at 08： 00—09： 00 am,which may related to the traffic. Meanwhile,the results indicated that most of the PM2.5 episodes were induced by the movement of a degraded cold high pressure system.