河源夏季臭氧污染特征及其成因

Characteristics and Source Attribution of Summer Ozone Pollution in Heyuan

2015年9月至2016年8月,在广东河源城区内采用在线连续观测,分析该地区近地面臭氧(O_3)及其前体物的变化规律和相关性,重点探讨了夏季O_3污染特征及成因。结果表明,河源市城区O_3总超标天数为10 d,主要集中在7—9月。O_3浓度变化呈现明显的春、冬季低,夏、秋季高的季节变化。O_3浓度日变化呈典型单峰特征,前体物主要呈双峰变化。O_3小时浓度和CO无明显的相关性,与NO2浓度呈现较高的负相关关系;气象及HYSPLIT-4模型计算综合分析结果表明,夏季污染时段河源高空、低空气团大部来自西南方向,夏季O_3污染主要来源于珠三角区域传输和本地源排放。

Continuous monitoring was conducted during September 2015 to August 2016 in urban area of Heyuan,to analyze the seasonal variation of troposphere ozone concentration and correlations with its precursors. Results showed that there were 10 days of ozone concentration higher than 200 μg/m3（ GB 3095-2012） during this period,which were mainly concentrated from July to September. Concentration of ozone was relatively high in summer and autumn,while low in spring and winter. The diurnal variation of ozone concentration showed a typical single peak at noon,while its precursors hadabimodal distribution. There was a significant negative relationship of per hour average concentration between ozone and NO2,but not between ozone and CO. The composite analysis of meteorology and HYSPLIT-4 showedthat during pollution period the air mass most from southwest in high or low sky,which indicated that during summer the ozone pollution in Heyuan was most form Pearl River Delta（ PRD） regions and local source emissions.