京津冀地区一次臭氧污染过程的数值模拟分析

Modeling of Ozone Pollution Episode in Jing-Jin-Ji Area

利用区域空气质量模型对京津冀地区2015年6月21日至27日一次近地面臭氧污染过程进行模拟,识别了京津冀地区的臭氧生成控制区,并对京津冀地区各城市的臭氧及其生成前体物NO_x和VOCs的来源进行解析。结果表明,京津冀地区除部分城市的中心城区为VOCs控制区域外,大部分地区为NO_x和VOCs的共同控制区,因此控制NO_x和VOCs排放均有利于减轻臭氧污染。京津冀地区各城市的NO_x和VOCs以本地贡献为主,但区域间的相互传输对各城市的臭氧浓度有很大影响。保定、承德和张家口本地NO_x排放对本地的NO_x贡献分别为89%、88%、95%;本地VOCs排放对本地的VOCs贡献分别为54%、33%、50%;本地排放对本地的臭氧贡献分别为14%、13%、18%。

The modeling of aground-level ozone pollution episode from June 21 stto 27th2015 in Jing-Jin-Ji area is conducted in this study.The NO_x and VOCs control zones are distinguished,and the regional source apportionments of ozone and its precursors（ NO_x and VOCs）are analyzed. The results show that the ozone formation in most cities in Jing-Jin-Ji area were in the NO_x and VOCs co-control zones,indicating that reducing both NO_x and VOCs emissions may bring down ozone concentrations; however,in some urban central areas,especially those with high NO_x level,O3 attainment might benefit from reducing VOCs emissions. The NO_x and VOCs concentrations in each city in Jing-Jin-Ji area were mostly contributed by local NO_x and VOCs emissions; however,O3 concentrations in each city were mostly contributed by regional transport. In Baoding,Chengde,and Zhangjiakou,89%,88% and 95% NO_x concentrations were contributed by local NO_x emissions respectively,and 54%,33% and 50% VOCs concentrations were contributed by local VOCs emissions respectively,while only 14%,13% and 18% O3 concentrations were generated by local NO_x and VOCs emissions respectively.