基于成像差分吸收光谱技术探测合肥市大气边界层NO2斜柱浓度分布研究  

Study on the Distribution of NO2 Slant Column Density in Atmospheric Boundary Layer of Hefei City Based on Imaging Differential Absorption Spectroscopy

作　　者：吴子扬 谢品华 徐晋[2] 李昂 张强 胡肇焜 李晓梅 田鑫 WU Zi-yang;XIE Pin-hua;XU Jin;LI Ang;ZHANG Qiang;HU Zhao-kun;LI Xiao-mei;TIAN Xin(School of Environmental Science and Optoelectronic Technology,University of Science and Technology of China,Hefei 230026,China;Key Laboratory of Environmental Optics&Technology,Anhui Institute of Optics and Fine Mechanics,Chinese Academy of Sciences,Hefei 230031,China;CAS Center for Excellence in Urban Atmospheric Environment,Institute of Urban Environment,Chinese Academy of Sciences,Xiamen 361021,China)

机构地区：[1]中国科学技术大学环境科学与光电技术学院,安徽合肥230026 [2]中国科学院安徽光学精密机械研究所,中国科学院环境光学与技术重点实验室,安徽合肥230031 [3]中国科学院区域大气环境研究卓越创新中心,福建厦门361021

出　　处：《光谱学与光谱分析》2020年第3期720-726,共7页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金项目(41530644);国家重点研发计划项目(2017YFC0209902)资助

摘　　要：近年来,中国经济发展迅速,工业化程度越来越高,大气环境污染问题加剧,严重影响人民的日常生活,因此对大气污染物的实时监测研究尤为重要。城市边界层大气中各类污染源排放的相互作用,使得其污染问题复杂多变,特别是在重污染过程中污染物在大气中的垂直分布和变化情况问题。成像差分吸收光谱(I-DOAS)技术用于对污染物空间分布的探测,国内外对该技术的研究主要基于地基扫描、机载和星载平台,因其具有长距离、多组分、高分辨同时连续实时观测的特点,观测范围可从小尺度逐渐向大区域拓展,可为分析大气环境现状提供重要数据支撑。地基成像差分吸收光谱技术一般用于对某一污染源的探测,主要研究其对城市大气边界层污染物分布的探测方法,其中介绍了基于比尔-朗伯定律的差分吸收光谱(DOAS)原理,分析了基于"推扫"方式的成像系统的成像原理,并且以大气中常见污染物NO2为例,2018年6月12日在合肥市科学岛开展对边界层大气NO2的成像遥测实验,将多芯光纤束前端与紫外镜头耦合,后端连接光谱仪狭缝,紫外镜头搭载于二维转台电机上,设置二维旋转电机合适的仰角,水平方向上从0°旋转至90°,观测区域中主要包括郊区,电厂区和城市区三个典型区域。选择天顶太阳光谱作为参考谱,将测量光谱、参考谱进行相应多通道光谱合并及提取,每采集一次可获得相对应的38条光谱。使用DOAS反演方法对所有测量光谱进行数据反演,得到38×90组NO2的差分斜柱浓度(DSCD),并根据观测角度的几何模型,将浓度信息与空间维上的像元相匹配,按照扫描方向进行依次插值重构,扣除复杂背景后,获得合肥市边界层NO2差分斜柱浓度的二维分布图像,并且与当天同时进行实验的MAX-DOAS观测数据作对比,两者在郊区、电厂区和城市区的相关系数分别为0.86,0.87和0.83,结果表明该系统In recent years,China’s economy has developed rapidly,industrialization has become higher and higher,and atmospheric pollution has intensified,seriously affecting people’s daily lives.Therefore,real-time monitoring and research on atmospheric pollutants is particularly important.The interaction of various pollution sources in the atmosphere of the urban boundary layer makes the pollution problem complex and variable,especially the vertical distribution and change of pollutants in the atmosphere during heavy pollution.Imaging differential absorption spectroscopy(I-DOAS)is used to detect the spatial distribution of pollutants.The research at home and abroad is based on ground-based scanning,airborne and space-borne platforms.Because of its long-distance,multi-component,high-resolution and continuous real-time observation,the observation range can be extended from small scale to large area,which can provide important data support for analyzing the current situation of the atmospheric environment.Ground-based imaging differential absorption spectroscopy is generally used to detect a certain pollution source.This paper mainly studies its detection method for urban atmospheric boundary layer pollutant distribution.It introduces the principle of differential absorption spectroscopy(DOAS)based on Beer-Lambert law,and introduces the imaging principle of imaging system based on"push-broom".Taking the common pollutant NO2 in the atmosphere as an example,on June 12,2018,the imaging telemetry experiment of NO2 in the boundary layer was carried out in Science Island of Hefei City.The front end of the multi-core fiber bundle was coupled with the ultraviolet lens,and the back end was connected to the slit of the spectrometer.The ultraviolet lens was mounted on the two-dimensional rotating motor.Set the appropriate elevation angle of the two-dimensional rotating electric machine,and rotated it from 0°to 90°in the horizontal direction.The observation area included the suburb,power plant area and urban area.The zenith solar s

关 键 词：差分吸收光谱 城市边界层 二氧化氮 二维分布成像 

分 类 号：O433.1[机械工程—光学工程]