College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China.
College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China; Key Laboratory of Marine Environment and Ecology, Ministry of Education, Ocean University of China, Qingdao 266100, China; Laboratory for Marine Ecology and Environmental Sciences, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, China.
J Environ Sci (China). 2019 May;79:225-238. doi: 10.1016/j.jes.2018.09.007. Epub 2018 Oct 5.
US EPA's Community Multiscale Air Quality modeling system (CMAQ) with Process Analysis tool was used to simulate and quantify the contribution of individual atmospheric processes to PM concentration in Qingdao during three representative PM pollution events in the winter of 2015 and 2016. Compared with the observed surface PM concentrations, CMAQ could reasonably reproduce the temporal and spatial variations of PM during these three events. Process analysis results show that primary emissions accounted for 72.7%-93.2% of the accumulation of surface PM before and after the events. When the events occurred, primary emissions were still the major contributor to the increase of PM in Qingdao, however the contribution percentage reduced significantly, which only account for 51.4%-71.8%. Net contribution from horizontal and vertical transport to the accumulation of PM was also positive and its percentage increased when events occurred. Only 1.1%-4.6% of aerosol accumulation was due to PM processes and aqueous chemical processes before and after events. When the events occurred, contribution from PM processes and aqueous chemistry increased to 6.0%-11.8%. Loss of PM was mainly through horizontal transport, vertical transport and dry deposition, no matter during or outside the events. Wet deposition would become the main removal pathway of PM, when precipitation occurred.
美国环保署的社区多尺度空气质量建模系统（CMAQ）与过程分析工具结合使用，模拟并量化了 2015 年和 2016 年冬季三个代表性 PM 污染事件期间个别大气过程对青岛 PM 浓度的贡献。与观测到的地面 PM 浓度相比，CMAQ 可以合理地再现这三个事件期间 PM 的时间和空间变化。过程分析结果表明，在事件前后，一次排放占地面 PM 积累量的 72.7%-93.2%。当事件发生时，一次排放仍然是青岛 PM 增加的主要贡献者，但贡献比例显著降低，仅占 51.4%-71.8%。水平和垂直传输对 PM 积累的净贡献也是正的，并且在事件发生时其百分比增加。在事件发生前后，气溶胶积累仅有 1.1%-4.6%归因于 PM 过程和水相化学过程。当事件发生时，PM 过程和水相化学的贡献增加到 6.0%-11.8%。PM 的损失主要通过水平传输、垂直传输和干沉降，无论在事件期间还是之外。当发生降水时，湿沉降将成为 PM 的主要去除途径。
