天津市夏季臭氧污染特征及来源的模拟分析

利用Models-3/CMAQ模式系统和高阶去耦合直接技术(HDDM-3D),对天津市2014年7月的臭氧(O3)污染进行模拟,分析臭氧生成的前体物控制区分布规律,量化天津市及周边地区排放的影响。研究结果表明,天津市臭氧浓度分布从中心城区向外部郊区逐渐增高,东南部临海的滨海新区浓度水平最高。天津全市7月的臭氧生成以VOCs控制为主,中部地区(中心城区、北辰区、东丽区、滨海新区)95%以上天数的臭氧处于VOCs控制区,北部远郊(蓟县、宝坻区、宁河区、武清区)以及中部津南区有2/3以上天数受VOCs控制,南部郊区(西青区、静海区、大港区)的VOCs控制区与共同控制区出现的比例相近。山东省排放是天津市夏季臭氧的主要来源,平均贡献占比约为1/4,对天津东南沿海地区的影响尤为突出;河北省排放平均贡献占比约为1/6,主要影响天津西部区县的臭氧水平;天津排放贡献则主要分布在北部的宝坻和蓟县。

Simulation of Pollution Characteristics and Source Apportionment of Ozone in Tianjin during Summer Time

Models-3/CMAQ and High-order Decoupled Direct Method (HDDM) was applied to simulate the ozone pollution during July 2014 in Tianjin, and then to analyze the distribution of ozone-precursor sensitivity regimes and to quantify the impact of source emissions from Tianjin and surrounding areas. The distribution of ozone concentration in Tianjin was gradually increased from the center urban areas to the suburbans areas. The concentrations in Binhai new district (in the southeast of Tianjin), was the highest. Ozone formation was mainly VOCs-sensitive in Tianjin in July, the central area (Central city, Beichen, Dongli and Binhai new district) was VOCs-sensitive over 95% days, near 2/3 of simulation days in northern suburbs (Jixian, Baodi, Ninghe and Wuqing) and Jinnan in central area was VOCs controlled, VOC-sensitive regime had similar probability of occurrence to mixed sensitive regime in southern suburbs (Xiqing, Jinghai and Dagang). Shandong Province contributed 1/4 to ozone in Tianjin, was the main source of Tianjin summer ozone, significantly influencing the level of ozone in the southeast coastal of Tianjin. The average contribute of Hebei Province was 1/6. It main effected of western area of Tianjin. Tianjin local emissions contributed in Baodi and Jixian in the north of Tianjin.