福建省近地层臭氧时空分布与超标天气成因

The Spatial and Temporal Distribution and Synoptic Causes of Surface Layer Ozone in Fujian Province

该文利用2015—2016年福建省9个设区城市和平潭综合实验区环境监测臭氧小时浓度观测资料,采用统计学方法,归纳臭氧的时空分布规律,开展臭氧超标的天气学成因分析。结果表明,福建省沿海地区的臭氧年平均浓度高于内陆地区,沿海地区又以宁德—厦门一线为高值中心,其中平潭综合实验区(位于福建中部沿海的海岛)臭氧浓度全省最高,年平均浓度约为其他城市的1.5~2.5倍。不同城市臭氧季节分布呈现出一定的差异性,有的是春季最高,有的是秋季最高,但一般都是冬季最低;沿海和内陆地区9—10月是臭氧平均浓度最高的月份,其次是4—5月,低值在12—1月;各市臭氧日分布规律较一致呈现"单峰型",午后是臭氧浓度高值区,夜晨处于低值区。以福州市为例,对2013年1月—2017年7月臭氧超标个例进行天气成因分析,臭氧超标主要有光化学反应型、本地积累型、水平输送型、垂直输送型等4种,对比分析不同类型下臭氧超标的气象要素、大气扩散条件、颗粒物浓度、高发月份和主导天气形势等特征,并列举臭氧超标的典型个例,为高浓度臭氧的预报预警和天气成因分析提供技术支持。

The spatial and temporal distribution and synoptic cause of surface layer ozone( O_3) pollution in 9 districts and Pingtan comprehensive experimental area of Fujian province were investigated by using O_3 hourly concentration data with statistical methods. The analysis results show that O_3 concentration( ρ( O_3)) in coastal area was higher than inland area of Fujian. The maximal value in coastal area distributed from Ningde to Xiamen. Annual ρ( O_3) in Pingtan was the highest concentration in Fujian,which was 1. 5 to 2. 5 times of others cities. ρ( O_3) seasonal distribution presented discrepancies in different cities,Some was peaked in spring while some was in summer.All were lowest in winter. The monthly concentration of O_3 in September and October was the highest,next was in April and in May,and December and January was the lowest. The diurnal variation in ρ( O_3) was one peak during a day,which reached peak value in the afternoon and was at the lowest stage before dawn. The synoptic causes of ρ( O_3) pollution were analyzed from January 2013 to July 2017 in Fuzhou,which could fall into following main types:photochemical reaction,local accumulation,horizontal transport and vertical transport. Typical O_3 pollutions were enumerated,and analyzed its meteorological factor,atmospheric diffusion conditions,particle concentration,high occurrence month and synoptic situation was compared in difference pollution. It provided technical support for the layer O_3 prediction and synoptic course analysis.