State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China.
Chengdu Academy of Environmental Sciences, Chengdu 610072, China.
Environ Pollut. 2017 Nov;230:718-729. doi: 10.1016/j.envpol.2017.07.029. Epub 2017 Jul 18.
Based on detailed data from Chengdu Plain (CP) from 6 January to 16 January, two typical haze episodes were analyzed to clarify the haze formation mechanism in winter. Weather conditions, chemical compositions, secondary pollutant transformation, optical properties of aerosols, the potential source contribution function (PSCF) and source apportionment were studied. The planetary boundary layer (PBL) height decreased distinctly during the haze episodes and restrained air pollutant vertical dispersion. As the haze worsened, the value of PBL × PM increased notably. The [NO]/[SO] ratio was 0.61, 0.76 and 0.88 during a non-haze period, episode 1 and episode 2, respectively, indicating that the mobile source of the air pollution is increasingly predominant in Chengdu. Water vapor also played a vital role in the formation of haze by accelerating the chemical transformation of secondary pollutants, leading to the hygroscopic growth of aerosols. The PSCF and backward trajectories of the air masses indicated that the pollution mainly came from the south. The secondary inorganic aerosols, vehicle emissions, coal combustion, biomass burning, industry, and dust contributed 34.1%, 24.1%, 12.7%, 12.3%, 7.6%, and 7.2% to PM masses in episode 1 and 28.9%, 23.1%, 9.4%, 9.5%, 20.3% and 7.5% in episode 2.
基于成都平原（CP）从 1 月 6 日至 16 日的详细数据，分析了两个典型的霾事件，以阐明冬季霾形成的机制。研究了天气条件、化学成分、二次污染物转化、气溶胶光学特性、潜在源贡献函数（PSCF）和源分配。霾事件期间，行星边界层（PBL）高度明显下降，抑制了空气污染物的垂直扩散。随着霾的加剧，PBL×PM 值显著增加。在非霾期、第 1 期和第 2 期，[NO]/[SO]比分别为 0.61、0.76 和 0.88，表明成都空气污染的移动源越来越占主导地位。水汽通过加速二次污染物的化学转化，对霾的形成也起着至关重要的作用，导致气溶胶的吸湿增长。PSCF 和空气团的后向轨迹表明，污染主要来自南方。二次无机气溶胶、车辆排放、煤炭燃烧、生物质燃烧、工业和扬尘分别贡献了 PM 质量的 34.1%、24.1%、12.7%、12.3%、7.6%和 7.2%，在第 1 期和第 2 期贡献了 28.9%、23.1%、9.4%、9.5%、20.3%和 7.5%。
