亚洲沙尘由蒙古戈壁向长江三角洲的传输及其与污染气溶胶的混合特征  

The Long-range Transport of Dust from Mongolia Gobi to the Yangtze River Basin and its Mixing with Pollutant Aerosols

作　　者：崔文岭[1] 郭瑞[1] 张浩[1] 

机构地区：[1]复旦大学环境科学与工程系,上海200433

出　　处：《复旦学报（自然科学版）》2009年第5期585-592,共8页Journal of Fudan University：Natural Science

基　　金：国家自然科学基金资助项目(20877020;40575062);国家重点基础研究发展计划资助项目(2006CB403704)

摘　　要：利用4个地面站点(多伦、北京、泰山、上海)组成的气溶胶采样网络观测了2007年春季亚洲沙尘的中长距离传输路线.通过后向/前向气团运动轨迹和特征示踪元素比值(Ca/Al)发现了此次沙尘的长距离传输源自蒙古戈壁,途径华北/东北、绕道东海,部分最后沉降于长江三角洲.经由对比分析传输途中各站点气溶胶的质量浓度、元素/离子组成等理化特征以及元素富集系数(EF),结果表明,沙尘源区由于人为污染源较少,气溶胶中矿物组分与污染物组分的相互混合不是很显著,随着沙尘往中国东部沿海地区的传输,颗粒物化学特征比值(SO42-/3)/S与∑+/∑-分别由0.65增大到1.0、3.21降至0.47,间接表明沿途污染源排放的人为气溶胶逐渐增加,沙尘颗粒上非均相反应的作用增强,气溶胶中沙尘矿物组分与污染性组分的混合和相互作用趋向强化,沙尘气溶胶颗粒愈加酸化.春天亚洲沙尘的长途传输是影响我国东部沿海地区包括诸多大城市的空气质量的不可忽视的重要外来源.A spring sampling campaign was carried out to monitor the Asian dust storm and its long-range transport across China in 2007.Combined with the backward/forward air mass trajectories analysis,the main low-Ca dust source from the northern China/Mongolia and the transport pathway from the Northern/Northeastern low Ca dust source regions to Shanghai,a downstream site in the Yangtze River Basin,were identified with the Ca/Al elemental tracer analysis.The chemical characterization of dust transport was conducted with examining the variations of mass concentrations,elemental/ionic compositions of dust from site to site,The result from the above analysis,in combination with elemental enrichment factor analysis indicated the mixing of dust particles with pollution was not so evident due to less anthropogenic sources from the near site of original source dust,in contrast to the downstream sites.While with the transport of dust to East China and accumulation of pollution aerosols,the chemical characteristic ratio value of particle,（SO2-4/3）/S and ∑＋/∑-,increased and decreased,from 0.65 to 1.00 and from 3.21 to 0.47,respectively,indicating the heterogeneous reaction on dust and mixing of mineral with pollution components during the dust transport were enhanced,and the acidification of particles was aggravated.Furthermore,in many cities of Eastern China severe degradation of air quality due to long-range transport of dust should be urgently concerned.

关 键 词：沙尘 源区 长途传输 气团运动轨迹 

分 类 号：X32[环境科学与工程—环境工程]