State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
J Environ Sci (China). 2012;24(4):645-56. doi: 10.1016/s1001-0742(11)60811-5.
Most previous O3 simulations were based only on gaseous phase photochemistry. However, some aerosol-related processes, namely, heterogeneous reactions occurring on the aerosol surface and photolysis rate alternated by aerosol radiative influence, may affect O3 photochemistry under high aerosol loads. A three-dimensional air quality model, Models-3/Community Multi-scale Air Quality-Model of Aerosol Dynamics, Reaction, Ionization, and Dissolution, was employed to simulate the effects of the above-mentioned processes on O3 formation under typical high O3 episodes in Beijing during summer. Five heterogeneous reactions, i.e., NO2, NO3, N2O5, HO2, and O3, were individually investigated to elucidate their effects on 03 formation. The results showed that the heterogeneous reactions significantly affected O3 formation in the urban plume. NO2 heterogeneous reaction increased O3 to 90 ppb, while HO2 heterogeneous reaction decreased O3 to 33 ppb. In addition, O3 heterogeneous loss decreased O3 to 31 ppb. The effects of NO2, NO3, and N2O5 heterogeneous reactions showed opposite O3 concentration changes between the urban and extra-urban areas because of the response of the reactions to the two types of O3 formation regimes. When the aerosol radiative influence was included, the photolysis rate decreased and O3 decreased significantly to 73 ppb O3. The two aerosol-related processes should be considered in the study of O3 formation because high aerosol concentration is a ubiquitous phenomenon that affects the urban- and regional air quality in China.
大多数先前的 O3 模拟仅基于气相光化学反应。然而，一些与气溶胶有关的过程，即在气溶胶表面上发生的多相反应以及气溶胶辐射影响引起的光解速率变化，可能会影响高气溶胶负荷下的 O3 光化学。采用三维空气质量模型 Models-3/Community Multi-scale Air Quality-Model of Aerosol Dynamics、Reaction、Ionization、and Dissolution 模拟了上述过程对北京夏季典型高 O3 期间 O3 形成的影响。单独研究了五个多相反应，即 NO2、NO3、N2O5、HO2 和 O3，以阐明它们对 O3 形成的影响。结果表明，多相反应显著影响了城市羽流中的 O3 形成。NO2 多相反应使 O3 增加到 90ppb，而 HO2 多相反应使 O3 减少到 33ppb。此外，O3 多相损耗使 O3 减少了 31ppb。NO2、NO3 和 N2O5 多相反应的影响在城市和城市以外地区表现出相反的 O3 浓度变化，这是由于反应对两种 O3 形成模式的响应。当考虑气溶胶辐射影响时，光解速率降低，O3 显著减少到 73ppb O3。由于高气溶胶浓度是影响中国城市和区域空气质量的普遍现象，因此在 O3 形成研究中应考虑这两个与气溶胶有关的过程。
