摘要
为实现对气溶胶光学参数的大范围、高精度、定量化探测,使用一套基于碘分子滤波器的机载高光谱分辨率激光雷达(HSRL)系统开展飞行实验,同时在地面设置辅助验证观测站。实验研究了秦皇岛地区的气溶胶变化趋势、不同下垫面类型下的气溶胶分布以及秦皇岛气溶胶光学厚度(AOD)的高值地区,并将HSRL系统反演的AOD数据与地面站点的太阳光度计和卫星遥感器测得的数据进行对比分析,三者相关性优于0.95。结合地面气象数据和机载观测数据,对不同飞行天次下秦皇岛地区的污染物来源以及城镇、山地、海洋等不同下垫面类型下的气溶胶光学参数分布特征进行分析,包括气溶胶后向散射系数、气溶胶消光系数、雷达比、色比和退偏比。结果表明:城镇地区的大气低层中以生物质燃烧和工业产生的气溶胶为主,海洋地区大气低层中以污染型海洋气溶胶为主,山地地区大气低层中的粒子尺寸较大,以污染型沙尘粒子为主。
Objective Aerosol plays an important role in assessing radiation,climate,cloud formation,and environmental pollution.In addition,the optical and physical properties of aerosols impact the formation and transmission of air pollutants.Therefore,the temporal and spatial distribution characteristics of tropospheric aerosols are important for studying the uncertainty of the aerosol environment and climate change.It is important to study the optical properties and vertical distribution changes of aerosols through effective observation methods.As a widely used active detection instrument of aerosols,lidar plays an irreplaceable role in the detection of vertical distribution of aerosol and changes in pollutant transmission.Related scholars have researched the distribution characteristics of aerosol extinction coefficient(AEC)and aerosol backscatter coefficient(ABC)profiles,as well as the regional pollution and climate impact by different types of aerosol distribution characteristics,which promotes the development of research methods and lidar detection.High spectral resolution lidar(HSRL)can detect aerosol optical parameters,such as AEC and ABC,enhancing the inversion accuracy of aerosol optical parameters.It provides an efficient method for accurate analysis of climate effects and long-term evolution characteristics of aerosols,as well as the evolution of regional and long-term pollution research.Methods In this study,the HSRL system based on an iodine molecular filter is used to conduct an aerosol observation experiment in Qinhuangdao in March,2019.Firstly,the correlation and absolute deviation between the aerosol optical depth(AOD)results retrieved by HSRL system and the data detected by the sunphotometer on the ground site and satellite remote sensor are discussed and analyzed.Combined with the AOD results of HSRL sysytem and ground meteorological data,the optical characteristics and pollution changes of aerosols during the pollution process in the Qinhuangdao area are studied.The distribution of aerosols on a polluted day and the characteristics of stable aerosol layers in cities and ocean areas are studied,and the vertical distribution and particle characteristics of aerosols corresponding to different underlying surfaces are analyzed.ABC,AEC,depolarization ratio(DR),lidar ratio(LR),and color ratio(CR)data are used to analyze the aerosol-concentration distribution and types of aerosol particles at different heights during the pollution process.The study analyzes the changes in aerosol optical parameters and pollutant characteristics during the pollution process.Results and Discussions According to the comparison results of AOD value,the correlation between the HSRL system and ground-based sunphotometer as well as that between the HSRL system and the satellite remote sensor are more than 0.99(Fig.3and Fig.4).We use airborne HSRL system to observe the aerosol distribution in Qinhuangdao,and analyze the distribution characteristics of high AOD areas and the changes in AOD at different dates.Combined with the meteorological data and airborne aerosol data,the pollution process in the Qinhuangdao area is analyzed.The pollution process is affected by the southwest wind(Table 3).The airborne observation data are used to analyze the vertical distributions and changes of aerosol parameters corresponding to different underlying surfaces at polluted days.AEC and ABC values on March 4,March 18,and March 19,2019are relatively large.The surface layer of the urban area of Qinhuangdao is dominated by industrial pollutants and fine particles produced during biomass combustion.The ABC and AEC values of the low layer decrease with the increase of height.The DR value is below 0.1,the LR value is between 35sr and 45sr,and the CR value is between 2.1and 2.5(Fig.7and Fig.8);the interaction between aerosol particles in the ocean area leads to the existence of a mixed aerosol layer,including polluted marine aerosols;aerosols in mountain areas are coarse sand and dust.Polluted dust aerosols dominate in some areas,with DR value between 0.1and 0.18(Fig.9).Conclusions Based on the aerosol data from the HSRL observation experiment,the study analyzes the vertical distribution and pollution characteristics of atmospheric aerosols in Qinhuangdao.We detect the AOD distributions in the east and west regions of Qinhuangdao at different dates,and the AOD observation results are correlated with ground-based and satellite observation data.In addition,we use meteorological data and airborne observation-aerosol data to analyze the boundary-layer changes and vertical distribution of aerosol optical parameters at different dates,and surface types.We observe that the aerosols in the low atmospheric layers of urban areas are mixed aerosols,whereas marine areas are dominated by polluted marine aerosols.The pollutant is a combination of various mixed aerosols.In addition,the types and changes of aerosols under different surface types are different.The pollution is caused by mixed aerosol produced by low-level industries and biomass combustion.The vertical distribution characteristics of three parameters(DR,LR,and CR)that characterized the types of aerosol particles at different dates and altitudes are given.The analysis results of this study reflect the advantages of HSRL system in detecting the vertical distribution of aerosols and regional pollution.Morever,this study provides reference value for the development and application of HSRL system,and supplies a favorable tool for the future development of regional aerosol pollution research.
作者
朱首正
卜令兵
刘继桥
王勤
杨巨鑫
张扬
竹孝鹏
陈卫标
Zhu Shouzheng;Bu Lingbing;Liu Jiqiao;Wang Qin;Yang Juxin;Zhang Yang;Zhu Xiaopeng;Chen Weibiao(Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters,Nanjing University of Information Science&Technology,Nanjing,Jiangsu 210044,China;Key Laboratory of Space Laser Communication and Detection Technology,Shanghai Institute of Optics and Fine Mechanics,Chinese Academy of Sciences,Shanghai 201800,China;Shanghai Institute of Satellite Engineering,Shanghai 201109,China)
出处
《中国激光》
EI
CAS
CSCD
北大核心
2021年第17期158-170,共13页
Chinese Journal of Lasers
基金
国家自然科学基金(41675133)
国家重点研究计划(2017YFF0104605)
民用航天预研项目(D040103)。
关键词
遥感
机载高光谱分辨率激光雷达
气溶胶垂直分布
气溶胶光学参数
污染分析
remote sensing
airborne high spectral resolution lidar
aerosol vertical distribution
aerosol optical parameters
pollution analysis
