Seasonal characterization of components and size distributions for submicron aerosols in Beijing  

作　　者：ZHANG YangMei SUN JunYing ZHANG XiaoYe SHEN XiaoJing WANG TingTing QIN MingKai 

机构地区：[1]Key Laboratory for Atmospheric Chemistry,Chinese Academy of Meteorological Sciences [2]Heilongjiang Province Meteorological Bureau [3]Fengtai District Meteorological Bureau of Beijing

出　　处：《Science China Earth Sciences》2013年第5期890-900,共11页中国科学（地球科学英文版）

基　　金：supported by National Natural Science Foundation of China (Grant No.41175113);National Basic Research Program of China(Grant No.2011CB403401);China International Science and Technology Cooperation Project(Grant No.2009DFA22800);Chinese Academy of Meteorological Sciences Group Project(Grant No.2010Z002)

摘　　要：Submicron aerosols （PMt） in Beijing were studied using an Aerodyne aerosol mass spectrometer （AMS） from January to Oc tober 2008. This paper presents seasonal variations of different chemical components （sulfate, nitrate, ammonium, chloride and organics） and size distributions of PM1. Results show that mass concentration of PMI was highest in summer, and lowest in autumn. Organics represented the dominant species in all seasons, accounting for 36%58% of PML, and their concentrations were highest in winter. Concentrations of inorganic components, sulfate, nitrate, and ammonium were highest in summer. Based on principal component analysis, organics were deconvolved and quantified as hydrocarbonlike and oxygenated organ ic aerosol （HOA and OOA, respectively）. HOA was highest in winter, accounting for about 70% of organics. However, OOA was highest in summer, and had lower values in autumn and winter. A similar diurnal pattern of various components was ob served, which is higher at nighttime and lower during daytime. HOA increased more dramatically than other species between 17：00 and 21：00 and peaked at noon, which could be related to cooking emissions. OOA, sulfate, nitrate, ammonium and chlo ride varied with the same trend. Their concentrations increased with solar radiation from 9：00 to 13：00, and declined with weakening solar radiation. Size distributions of all species showed apparent peaks in the range 500600 nm. Size distributions of organics were much broader than other species, particularly in autumn and winter. Distributions of sulfate, nitrate and am monium had similar patterns, broadening in winter. Contributions of different species were sizedependent; the finer the parti cle, the greater the contribution of organics. Organics represented more than 60% of particles smaller than 200 nm, contrib uting 50% to PM1 in winter. In spring and summer, HOA was the dominant organic fraction for particles smaller than 200 nm, while OOA contributed more to particles larger than 300 nm. In winSubmicron aerosols(PM1)in Beijing were studied using an Aerodyne aerosol mass spectrometer(AMS)from January to October 2008.This paper presents seasonal variations of different chemical components(sulfate,nitrate,ammonium,chloride and organics)and size distributions of PM1.Results show that mass concentration of PM1 was highest in summer,and lowest in autumn.Organics represented the dominant species in all seasons,accounting for 36%-58%of PM1,and their concentrations were highest in winter.Concentrations of inorganic components,sulfate,nitrate,and ammonium were highest in summer. Based on principal component analysis,organics were deconvolved and quantified as hydrocarbon-like and oxygenated organic aerosol(HOA and OOA,respectively).HOA was highest in winter,accounting for about 70%of organics.However,OOA was highest in summer,and had lower values in autumn and winter.A similar diurnal pattern of various components was ob- served,which is higher at nighttime and lower during daytime.HOA increased more dramatically than other species between 17:00 and 21:00 and peaked at noon,which could be related to cooking emissions. OOA,sulfate,nitrate,ammonium and chloride varied with the same trend.Their concentrations increased with solar radiation from 9:00 to 13:00,and declined with weakening solar radiation.Size distributions of all species showed apparent peaks in the range 500-600 nm.Size distributions of organics were much broader than other species,particularly in autumn and winter.Distributions of sulfate,nitrate and ammonium had similar patterns,broadening in winter.Contributions of different species were size-dependent;the finer the particle,the greater the contribution of organics.Organics represented more than 60%of particles smaller than 200 nm,contributing 50%to PM1 in winter.In spring and summer,HOA was the dominant organic fraction for particles smaller than 200 nm, while OOA contributed more to particles larger than 300 nm.In winter,HOA contributed more than OOA to all PM1 particles.

关 键 词：AEROSOL chemical components size distribution AMS seasonal variation BEIJING 

分 类 号：P427.2[天文地球—大气科学及气象学]