基于CAMx模型的珠江口东岸秋季臭氧来源解析

Ozone Source Apportionment in East Coast of the Pearl River Estuary Based on the CAMx Model

秋季是广东省臭氧(O_3)污染最严重的季节。以三维空气质量模型(CAMx)为工具,选取深圳西乡为研究对象,综合运用多种手段深入研究珠江口东岸秋季O_3污染过程及生成的敏感性,并定量研究了O_3的来源。结果表明:受偏北贴地气流的影响,珠江口东岸秋季容易发生O_3污染;珠江口东岸秋季午后O_3浓度有约60%是背景浓度,深圳本地排放对O_3的贡献较少,而周边地区东莞市和惠州市对O_3的贡献较大(午后O_3最高浓度约10μg/m3),梅州市、河源市和广州市也有一定的O_3贡献,但广东省其他地区对O_3的贡献较少,可以忽略,而江西省和福建省对O_3的贡献较大,在午后约有20%~30%的O_3浓度贡献;按排放类型分,除去背景浓度,秋季对珠江口东岸O_3贡献最大的排放源是火电、工业和飞机高架排放源,午后O_3浓度贡献可达15μg/m3,其次是天然源和交通源,午后O_3浓度分别各贡献10μg/m3左右;秋季,珠江口东岸的O_3在早上与傍晚大多在NOx敏感区内生成,中午前后更多的O_3在VOCS敏感区内生成。要控制珠江口东岸地区的O_3污染,应在秋季重点控制北面省市的火电、工业高架源排放等。

Ozone pollution is the most serious in autumn in Guangdong province. This paper employs a three dimensional air quality model CAMx and selects Xixiang of Shenzhen as the study area. The paper studies the pollution process and formation sensitivity of ozone and quantitative ozone source of the east coast of Pearl River Estuary using comprehensive means. The results show that affected by the north near ground air,east coast of the Pearl River estuary is prone to ozone pollution in autumn. About 60% of the ozone at the east coast of Pearl River Estuary in the afternoon in autumn is background concentration. Local emissions contribute relatively less ozone, while the ozone contribution from Dongguan and Huizhou are rela-tively high,with the maximum concentration of about 10μg/m^3 in the afternoon. There are certain ozone contributions from Meizhou, Heyuan and Guangzhou, while the contributions from other cities of Guang-dong province are much less and can be ignored. The ozone contributions from Jiangxi and Fujian provinces are about 20%-30% in the afternoon. Divided by source sectors,excluding the background concentration, the largest contributors to autumn ozone concentrations are power plants, elevated sources of industrial and aircraft emissions,with the contribution up to 15μg/m^3 in the afternoon;and followed by natural and traf- fic emissions contributing about 10μg/m^3 respectively. In autumn,most of the ozone in the east coast of the Pearl River Estuary is generated in NOx sensitive region in the morning and late afternoon, while more o-zone generated in the VOCs sensitive region near the noon. To reduce ozone pollution in this region,power plants and industrial elevated sources in the north provinces and cities should be taken as a priority in au- tumn.