Process analysis of regional ozone formation over the Yangtze River Delta, China using the Community Multi-scale Air Quality modeling system
Process analysis of regional ozone formation over the Yangtze River Delta, China using the Community Multi-scale Air Quality modeling system
复制标题
使用社区多尺度空气质量建模系统对中国长江三角洲区域臭氧形成过程进行分析
DOI：
10.5194/acp-12-10971-2012
复制
发表时间：
2012-01-01
影响因子：
6.3
通讯作者：
Jang, C. J.
中科院分区：
文献类型：
--
作者：
Li, L.;Chen, C. H.;Jang, C. J.
抽象。2010年8月，长江三角洲地区的典型城市上海市发生了一次高O3浓度事件。采用CMAQ积分过程率法计算了高污染时段不同大气过程的贡献。分析表明，臭氧浓度最大值的出现是由于输送现象，包括垂直扩散和水平平流输送。产生O3的气相化学作用主要发生在300-1500 m高度，导致O3从高层向近地层的强烈垂直输送。气相化学是一个重要的汇O3在表面层，加上干沉积。云的过程可能会稍微增加O3由于对流云或O3的减少，由于清除。水平扩散和非均匀化学贡献在整个事件中可以忽略不计。模拟结果表明，长三角地区不同城市间的O3污染特征既有相似性，也有差异性。在形成期间，O3开始出现在长三角城市地区，然后在盛行风条件下被输送到周边地区。由于大城市排放强度高，上海及周边地区光化学反应产生的O3最为显著;这些臭氧随后被西风气流输送到海上，随后扩散到崇明岛、无锡甚至南京等农村地区。日落后，由于NO排放量的滴定，城市中的O3浓度开始下降，但在NO排放量非常小的农村地区甚至YRD地区以外的地区，臭氧仍然可以传输并保持显着的浓度。
Abstract. A high O3 episode was detected in urban Shanghai, a typical city in the Yangtze River Delta (YRD) region in August 2010. The CMAQ integrated process rate method is applied to account for the contribution of different atmospheric processes during the high pollution episode. The analysis shows that the maximum concentration of ozone occurs due to transport phenomena, including vertical diffusion and horizontal advective transport. Gas-phase chemistry producing O3 mainly occurs at the height of 300–1500 m, causing a strong vertical O3 transport from upper levels to the surface layer. The gas-phase chemistry is an important sink for O3 in the surface layer, coupled with dry deposition. Cloud processes may contribute slightly to the increase of O3 due to convective clouds or to the decrease of O3 due to scavenging. The horizontal diffusion and heterogeneous chemistry contributions are negligible during the whole episode. Modeling results show that the O3 pollution characteristics among the different cities in the YRD region have both similarities and differences. During the buildup period, the O3 starts to appear in the city regions of the YRD and is then transported to the surrounding areas under the prevailing wind conditions. The O3 production from photochemical reaction in Shanghai and the surrounding area is most significant, due to the high emission intensity in the large city; this ozone is then transported out to sea by the westerly wind flow, and later diffuses to rural areas like Chongming island, Wuxi and even to Nanjing. The O3 concentrations start to decrease in the cities after sunset, due to titration of the NO emissions, but ozone can still be transported and maintain a significant concentration in rural areas and even regions outside the YRD region, where the NO emissions are very small.