摘要
利用天顶被动DOAS(Differential Optical Absorption Spectroscopy)和主动长程DOAS系统分别反演出2007年93 d的对流层NO2垂直柱密度和近地面NO2的平均浓度.近地面NO2日均浓度CSurface≥8.0×10-2mg·m-3(Air Pollution Index,API=50)和对流层NO2日均垂直柱密度VCDTotal(VCD,Vertical Column Density)≥6.03×1016molecule·cm-2(API=50相对应的VCD)时,分别为低空NO2污染和高空NO2污染,据此将93 d的数据分为NO2低污染、NO2高污染、高空NO2污染和低空NO2污染4类情形,并结合混合层高度和气象条件等因素分析了产生原因.结果表明:在NO2污染源相对固定的情况下,混合层高度和风速、风向等气象条件是影响地面NO2浓度的主要因素;对流层NO2垂直柱密度的变化主要受内陆污染大气输送、局地污染源释放和混合层高度等因素影响.研究发现地面NO2监测数据与整层大气NO2浓度相关性不高,需将对流层大气NO2垂直柱密度、地面NO2浓度、气象条件及混合层高度等因素有机结合起来才能够较科学地分析城市大气NO2污染.
Tropospheric NO2 vertical column density（VCDTotal） and NO2 surface concentration（CSurface） of 93 d in 2007 were obtained using Zenith-sky Passive DOAS（Differential Optical Absorption Spectroscopy）and long-path Active DOAS techniques.With CSurface ≥ 8.0×10^-2 mg·m^-3（API=50） assumed as low-altitude NO2 pollution,and VCDTotal ≥6.03×10^16molecule ·cm^-2（VCD corresponding to API=50） as upper-altitude NO2 pollution,the 93 d were categorized into light NO2 pollution,severe NO2 pollution,upper-altitude NO2 pollution and low-altitude NO2 pollution,the causes of which were analyzed consideringmixing height andmeteorological condition.The results indicated that with the relatively stable sources of NO2,mixing height,wind speed and wind direction were themain reasons for the change of NO2 surface concentration.NO2 vertical column density wasmostly influenced by the transportation of inland polluted air,local emissions andmixing height.The research found NO2 surface data had not so good relation with the NO2 concentration of the whole atmosphere.Only when considering NO2 vertical column density,NO2 surface concentration,meteorological condition,mixing height and other factors can we reasonably analyze urban NO2 pollution.
出处
《复旦学报（自然科学版）》
CAS
CSCD
北大核心
2011年第2期199-205,共7页
Journal of Fudan University：Natural Science
基金
国家高技术研究发展计划(863计划)资助项目(2006AA06Z417)
