西安大气细颗粒(PM_1)化学组成及其对能见度的影响  

Chemical Composition of Atmospheric Fine Particle (PM_1) and Its Effect on Visibility in Xi'an

作　　者：王浥尘[1,2] 曹军骥[1,3] 张宁宁[1,2] 肖舜[4] 王启元[3] 陈阳[1] 

机构地区：[1]中国科学院地球环境研究所气溶胶科学与技术重点实验室,陕西西安710075 [2]中国科学院大学,北京100049 [3]西安交通大学能源与动力工程学院,陕西西安710049 [4]陕西省气象局,陕西西安710014

出　　处：《地球科学与环境学报》2014年第3期94-101,共8页Journal of Earth Sciences and Environment

基　　金：国家自然科学基金重点项目(41230641)

摘　　要：在2012年秋季选取天气状况相对稳定的12d,运用细颗粒化学组分在线观测仪(ACSM),观测西安大气颗粒物变化;利用正矩阵因子分析法(PMF)对大气细颗粒物中的有机物进行源解析,探讨其对能见度的影响;最后,结合IMPROVE公式中吸湿增长因子和多元线性回归统计方法重建散光系数。结果表明:在观测时段,PM1(不包括黑碳和矿尘等难熔组分)和PM2.5质量浓度时间序列的相关性较好(判定系数为0.67),PM1约占PM2.5质量浓度的60%,有机物约占PM1质量浓度的58%,其他组分(包括SO2-4,NO-3,NH+4和Cl-)约占42%;高相对湿度(大于85%)伴随着一次组分质量分数的增加,雨水对一次组分的湿沉降作用也更加明显;利用正矩阵因子分析法对有机物进行源解析,分解出烃类有机气溶胶(HOA)和氧化性有机气溶胶(OOA)两种组分;OOA约占有机物质量浓度的54%,HOA约占46%,并且在下午时段,HOA发生挥发,经过光化学反应快速转化为OOA;硝酸盐对光的散射贡献最大。12days with relative steady weather conditions in autumn of 2012 were selected,and the variation of atmospheric fine particle in Xi＇an was measured by aerodyne aerosol chemical speciation monitor（ACSM）;source apportionment of organics from atmospheric fine particle was analyzed by the means of positive matrix factorization（PMF）,and the effect of atmospheric fine particle on visibility was discussed;finally,the scattering coefficient was reconstructed by the means of hygroscopic growth factors from IMPROVE equation and multi-linear regression statistical method.The results show that the correlation between time series of mass concentrations ofnon-refractory PM1（except for black carbon and mineral dust）and PM2.5is significant with a determination coefficient of 0.67 at the observation session;the mass concentration of nonrefractory PM1 is about 60% of PM2.5,and the mass concentration of organic is about 58% of PM1,other components（including SO4^2-,NO3^-,NH4^＋and Cl^-）is about 42%;higher relative humidity increases the mass fraction of primary component,and rainfall significantly improves the wet deposition of primary component;hydrocarbon-like organic aerosol（HOA）and oxygenated organic aerosol（OOA）are resolved from organics by the means of PMF;mass concentration of OOA is about 54%of organics,and that of HOA is about 46%;HOA volatilizes and translates to OOA after a photochemical reaction in the afternoon;nitrate contributes most to light scattering coefficient.

关 键 词：大气细颗粒 PM1 PM2.5 能见度 有机气溶胶 散光系数 西安 

分 类 号：X131.1[环境科学与工程—环境科学] P427.2[天文地球—大气科学及气象学]