地基全天空扫描二维MAX-DOAS系统获取大气痕量气体和气溶胶空间分布的方法和应用研究

Obtaining the point distribution of atmospheric pollutants and the concentration at a single azimuth has been far from meeting the requirements of pollution control. An optical remote sensing method capable of simultaneously obtaining the spatial distribution of atmospheric trace gas and aerosol at multiple angles and in all directions is urgently needed. The project intends to use differential absorption spectroscopy as the basis to carry out the research on the spatial distribution of atmospheric aerosols and polluted gases. The full-sky scanning two-dimensional multi-axis differential absorption spectroscopy (2D MAX-DOAS) system is designed and integrated. The measurement spectrum at the exact angle of the whole sky is obtained. Fast and high spatial resolution inversion pattern and stable inversion algorithms for vertical distribution is determined. Combined with the simulation results of the model, the performance of the algorithm is evaluated. The trace gas information at each azimuth of the measuring point is obtained. A visual spatial distribution is finally formed. Field observation experiments is carried out to achieve the simultaneous acquisition of the full spatial distribution of atmospheric aerosol and trace gas concentrations, and the comparison experiment is carried out to evaluate the inversion methods and results. Based on the time series of pollutant concentration, the temporal and spatial evolution of pollutants will be studied. The formation and spread of different azimuth pollution is studied for the pollution source localization. This technology will play more important role in urban pollution controlling.

获得大气污染物的点分布和单一方位角上的浓度已无法满足治理污染的要求，亟待一种能够多方位、多高度同时获得大气痕量气体和气溶胶空间分布的光学遥感方法。项目拟以差分吸收光谱技术为基础，开展对大气痕量气体和气溶胶全天空分布观测方法研究。设计与集成地基全天空扫描二维多轴差分吸收光谱系统（MAX-DOAS）；获取全天空准确角度下的测量光谱；确定快速、高空间分辨率的反演模式和稳定垂直分布反演算法；结合模型仿真验证算法的反演效果，评估算法的性能，获取测量点多方位角、不同高度的污染物空间分布信息；最终形成可视化的空间分布图。开展外场观测实验，实现大气痕量气体和气溶胶全空间分布的同步获取，并开展比对实验，评估反演方法和结果。基于污染物浓度时间序列，研究污染物的时空演变规律；定位污染源，为城市污染防控提供技术支持。

针对获取大气污染物的单一方位角上的浓度分布已无法满足精准定位污染源的需求，本项目研究了一种能够多方位、多高度同时获得大气痕量气体和气溶胶空间分布的光学遥感方法。构建了能够全天空观测的地基和车载二维MAX-DOAS系统，研制了高灵敏、低噪声的探测系统和精准的二维控制系统。获得痕量气体和气溶胶的水平分布（方位角扫描）和垂直分布（仰角扫描）。利用二维多轴差分吸收光学系统（MAX-DOAS），实现全天空准确角度下的光谱测量。针对中国地区的气溶胶和污染气体浓度变化较为剧烈而且高浓度状态时有发生的特点，研究了适合中国大气环境的气溶胶和污染气体浓度反演算法。结合模型仿真验证算法的反演效果，评估算法的性能，获取测量点多方位角、不同高度的污染物空间分布信息。把观测系统和反演方法应用于外场实验中。. 通过系统观测的O4气体差分斜柱浓度，结合大气辐射传输模型，反演气溶胶消光廓线和光学厚度。利用该气溶胶消光廓线和大气辐射传输模型建立了不同仰角下获取痕量气体垂直柱浓度和垂直分布廓线的方法。将反演方法应用于外场观测实验中，获取了气溶胶消光廓线和光学厚度，反演了对流层NO2、HCHO、SO2垂直柱浓度和垂直分布廓线，并对污染物的大气垂直分布和污染来源进行了分析。开展了大气常规污染物SO2、NO2和HCHO浓度的日变化、月变化、季节变化、年变化观测。并将观测结果分别与卫星测量结果和哥白尼大气监测服务模型进行对比，结果表明均具有较好的相关性。