以细颗粒为特征的大气复合污染问题对我国东部地区生态环境带来严峻挑战。近期的研究表明，当前我国重污染地区颗粒物浓度之高，足以影响与空气污染形成自身所密切相关的大气边界层气象条件，从而通过反馈作用加剧污染。然而，由于缺乏比较系统的集成观测（尤其是垂直理化结构的观测），目前对相关过程在大气复合污染形成中的定量贡献在认识上尚有较高的不确定性。本项目拟在颗粒物浓度高、太阳辐射强的长三角地区开展研究。通过在城市群下风向的南京开展多超级站的协同观测，探测大气边界层垂直方向理化结构和地基多过程、多参数，揭示地表能量平衡和大气辐射加热在边界层演变中的贡献，认识大气层结变化所引起的局地污染积累与二次污染转化速度的改变对复合污染形成的影响；同时针对双向反馈模型关键过程参数化方案和关键参数选择进行优化，从而定量研究空气污染-大气边界层相互作用对区域大气复合污染形成的贡献，并针对相关问题提出控制对策建议。

Characterized with high concentration of fine particular matter (PM), the regional-scale complex atmospheric pollution has brought serious challenge to the ecosystem and society. Recent studies showed that the concentration of PM was high enough to modify meteorological conditions in the Planetary Boundary Layer (PBL), which are key factors influencing the air quality, and hence to enhance the air pollution through this feedback loop. However, because of a lack of comprehensive integrated observations, especially those for the vertical measurement of the physical and chemical parameters in the PBL, there are high uncertainties in the understanding of quantitative impact of such kind of feedback on the regional haze pollution.. Here, we propose a study to address this issue in the Yangtze River Delta, a region with heavy haze pollution and relatively strong solar radiation. Intensive field complains will be conducted at several super-sites in Nanjing, a city downwind of the YRD city cluster, to detect the vertical structure of PBL physical and chemical parameters and multi-processes/ parameters around the ground surface. Based on these data, we will investigate the contributions of surface energy budget and vertical heating induced by aerosol layers to the development of PBL, and will also try to quantitatively understand the influence of local air pollution accumulation, enhanced by the change of PBL dynamics, and that of secondary formation induced by the change in meteorology conditions. We will improve the meteorology-chemistry two-way coupled numerical model by using optimized parameterization schemes or key parameters based on the measurement and our new findings. This model will be use to quantitatively understand the impact of air pollution-PBL feedback on regional haze pollution from a larger scale. Relevant control policy will also be raised to improve the air quality efficiently by considering the air pollution-PBL feedback.