长江三角洲地区臭氧污染时空分布特征

摘要

利用2013年6月至2014年5月长三角地区16个城市环境监测站点的臭氧小时浓度数据,分析长三角地区臭氧污染时空分布特征.结果表明,长三角地区臭氧浓度呈现夏季高、冬季低的季节变化特征.近海城市臭氧年均浓度较高,均高于60μg·m-3,内陆城市浓度较低,均低于50μg·m-3,而NO2分布与之相反,呈现夏季低、冬季高的季节变化特征.长三角地区四季臭氧日变化皆为典型的单峰型,夏季日最小值出现在06:00,其他季节推迟约1 h,日最大值均出现在15:00前后.夏季臭氧日变化的峰值浓度最大,为168μg·m-3,冬季臭氧日变化的峰值浓度最小,为85μg·m-3.%Based on the hourly ozone concentration data accumulated by the environmental monitoring stations in 16 cities during the period from June 27,2013 to May 30,2014, spatio-temporal distribution of ozone pollution over the Yangtze River Delta Region was analyzed and characterized. Results show that the annual mean O3 concentrations in coastal cities were all over 60 μg·m-3, much higher than those, being below 50 μg·m-3, in inland cities, and the distribution of NO2 was just opposite to that of O3 in pattern. O3 concentration in the region varied seasaonally, that is, high in summer, and low in winter, particularly in December. In summer, the over standard rate of O3 concentration was very high, going beyond 25% in 5 of the 16 cities, and in spring it was also high, particularly in Nanjing reaching over 20%. The daily var-iation of O3 concentration was a typical"single-peak" pattern, regardless seasons. The lowest value appeared at about 6 a. m. in summer, and an hour later in all the other seasons. The peak value appeared at about 3 p.m. in all the seasons. In summer the peak value might reach as high as 168 μg·m-3 while in winter the peak value was 85 μg·m-3 .