静稳型重污染过程的大气边界层机理与模式应用研究

The air pollution is related to a number of phenomena, such as the sources of pollution and the meteorological conditions. Among these factors, the atmospheric boundary layer has a direct influence on the temporal－spatial distribution of air pollution. The heavy air pollution is closely connected with the calm-wind and the stable conditions while the stable boundary layer and weak turbulence are both the difficulties of the study of atmospheric boundary layer and the key problems of the boundary-layer mechanism under heavy air pollution..Based on the needs of the study on the heavy air pollution in northern China, this application makes use of the intensive observations under heavy pollution conditions in the atmospheric boundary layer 1) to study the structures of the stable boundary layer, the atmospheric characteristics for heavy air pollutions and the observational techniques of weak turbulence; 2) to discuss the interactions between the stable boundary layer and the heavy pollution events; 3) to improve and develop the parameterization for the stable boundary layer which is more suitable for heavy air pollution events; and 4) to verify the prediction model of air quality..This application is aimed at the development and breakthrough on the similarity of the stable boundary layer, turbulent intermittency, the mixing and diffusion of weak turbulence, the observational techniques for weak turbulence, and so on. The related findings will develop the knowledge, research and observation about the stable boundary layer, reveal the meteorological mechanism of heavy air pollution, and improve the prediction model as well as the predictive abilities for air quality. In summary, these findings are of great meanings and targeted on real-life conditions, which will provide scientific and data basement for the control of air pollution.

空气污染问题涉及污染源、气象条件等诸多因素，大气边界层直接影响污染物的时空分布。重污染过程多对应静稳型天气，稳定边界层是大气边界层研究的科学难点，更是重污染过程边界层机理研究的关键问题。.本申请结合我国重污染频发的现实需求，利用大气边界层和大气环境精细实验资料，开展稳定边界层理论和观测法研究、重污染事件稳定边界层结构和理化特征研究，探讨稳定边界层结构与重污染的相互作用和影响，改进和发展适合华北地区的稳定边界层参数化方案，验证空气质量预报模型。.本申请力图在稳定边界层相似性和参数化方案、弱湍流扩散属性等方面有所突破。其成果将提升稳定边界层研究能力和水平，揭示静稳型重污染的边界层机理，改进空气质量预报模型和预报水平。研究结果具有重要的学术意义和实际针对性，可为华北区域空气质量控制提供科学依据和基础。

污染物的时空分布与大气边界层演变密切相关。伴随重霾污染的静稳型天气、稳定边界层、弱湍流运动是大气边界层领域的科学难点，也是解析重污染机理的关键问题。本研究在华北地区开展大气边界层和大气环境综合观测，提出了大气边界层和大气环境探测新技术和新方法，给出了大气边界层与重霾过程相互作用机理，发现了多层湍流隔板效应，揭示了重霾过程湍流作用机制，拓展了Monin-Obukhov相似性理论，给出了颗粒物通量-廓线关系，发展了边界层和颗粒物湍流输送参数化方案，并进行数值模式验证。.本研究利用天津气象塔、华北北部大气环境监测平台、北京城区和郊区大气环境实验场，实施大气湍流和大气环境长期观测。在山东德州、河北沧州和保定等区域开展多次加强实验，包括：大气污染物湍流扩散示踪物实验，含颗粒物廓线的高分辨GPS加密探空实验。同步收集华北地区大气边界层和大气环境观测资料。研发的气压脉动仪和细颗粒物湍流通量测量系统在多实验站、多高度实现长期连续运行，性能指标均满足要求。.开展重霾过程与湍流运动相互作用机理研究。开发了湍流谱隙自动识别算法，区分动力和热力作用，定义不同尺度的、可定量描述湍流间歇性的湍流间歇指数，给出湍流通量高估的修正依据。发现间歇湍流在污染消散阶段对污染物浓度降低的作用；提出重霾过程存在多层湍流隔板效应，揭示了重霾过程与大气边界层的相互作用机制；拓展Monin-Obukhov相似性理论，给出了细颗粒物湍流通量-廓线关系及相应参数化方案；重新审视城市化与湍流间歇特征、污染天气的关系，对比轻、重污染天气的湍流间歇特征。给出颗粒物浓度时空分布与大气边界层演变的关系，提出确定大气边界层高度的新算法。发展了一种基于印痕模型和排放清单反演华北平原PM2.5浓度的快速预报方法，解决污染物溯源难题。.研究结果对提高空气质量预报效果，理解重霾过程物理机理和边界层过程有重要学术意义和应用价值。.