基于卫星遥感和地面观测资料的汾渭平原空气污染分析

Statistical analysis of air pollution in Fenwei Plain based on satellite remote sensing and ground observation data

选取中国汾渭平原地区作为研究对象,利用MODIS、OMI和CALIPSO多源卫星遥感资料,同时结合环境监测国控站点污染6要素等逐小时地面环境监测数据以及能见度、霾天气现象记录等地面气象要素资料,综合分析了2013—2018年秋冬季汾渭平原空气质量状况、气溶胶的组分,探讨了卫星遥感气溶胶光学厚度(Aerosol Optical Depth,AOD)与地面污染物浓度的关系,并结合中国气象局化学天气预报系统-EMI评估模式(CUACE-EMI)资料对气象条件和污染减排影响进行评估。结果表明:11个代表城市中有6个城市秋冬季有接近或超过一半的时刻处于污染状态,且污染发生时,各代表城市大多数时刻处于中度及其以上污染级别;三门峡、临汾、运城和西安是霾和重度霾高发的城市,其重度霾爆发频率高达11.63%—14.78%;汾渭平原秋冬季首要污染物为PM 2.5和PM 10,以污染沙尘、沙漠沙尘和烟尘为主,出现频率分别为36.24%、25.14%和22.96%;MODIS AOD与空气质量指数(Air Quality Index,AQI)、PM 2.5、PM 10质量浓度之间的相关系数分别为0.72、0.70和0.64;汾渭平原2018年气象条件的变化使PM 2.5浓度较2013年、2014年、2015年、2016年和2017年同期上升了17.06%、1.58%、4.34%、11.25%和5.75%,减排措施使PM 2.5浓度较2013年、2014年、2015年、2016年和2017年同期分别下降了8.74%、28.01%、4.93%、3.16%和42.62%。

Based on remote sensing data from the MODIS satellite,the Ozone Monitoring Instrument(OMI)and the CALIPSO Lidar,the hourly surface concentrations of six criteria air pollutants observed at national environmental monitoring stations,and the surface meteorological data such as visibility and haze records,we comprehensively analyzed air quality and aerosol composition over Fenwei Plain during autumn and winter of 2013-2018 and investigated the relationship between the satellite-retrieved aerosol optical depth(AOD)and surface pollutant concentrations.In addition,meteorological conditions and the effects of emission reduction were assessed using the chemical weather forecasting system-EMI evaluation model(CUACE-EMI)developed by the China Meteorological Administration.The results show that six among the eleven representative cities suffer from air pollution for nearly or more than half of the whole autumn and winter.When air pollution occurs,the pollution level mostly reaches moderation and above at these representative cities.Haze and heavy haze occur frequently in Sanmenxia,Linfen,Yuncheng,and Xi′an,with the occurrence frequency of severe haze of 11.63%-14.78%.The primary pollutants are PM 2.5 and PM 10 and dominantly consist of polluted dust,desert dust,and smoke dominate,with the occurrence frequency of 36.24%,25.14%,and 22.96%,respectively.The correlation coefficients between MODIS-retrieved AOD and air quality index(AQI),PM 2.5,and PM 10 concentrations are 0.72,0.70,and 0.64,respectively.Compared with each year from 2013 to 2017,meteorological conditions contributes with an increase of PM 2.5 concentration in 2018 by 17.06%,1.58%,4.34%,11.25%,and 5.75%,respectively,emission reduction measures results in a decrease of PM 2.5 concentration in 2018 by 8.74%,28.01%,4.93%,3.16%,and 42.62%,respectively.