A comparison of summertime secondary organic aerosol source contributions at contrasting urban locations.
A comparison of summertime secondary organic aerosol source contributions at contrasting urban locations.
复制标题
DOI：
10.1021/es8025209
复制
发表时间：
2009-04
影响因子：
11.4
通讯作者：
E. Stone;Jiabin Zhou;D. C. Snyder;A. Rutter;M. Mieritz;J. Schauer
中科院分区：
文献类型：
--
作者：
E. Stone;Jiabin Zhou;D. C. Snyder;A. Rutter;M. Mieritz;J. Schauer
在三个北美城市地区对7月和8月期间大气有机气溶胶的主要和次要来源进行了定量评估：中西部地区的俄亥俄州克利夫兰和密歇根州底特律，以及洛杉矶空气盆地的加利福尼亚州河滨。用气相色谱-质谱法测定了初级气溶胶来源特有的有机分子标志物和异戊二烯、α-品烯、β-石竹烯和甲苯衍生的次级示踪剂。使用化学质量平衡(CMB)模型估算了机动车、生物质燃烧、植物碎屑和二次有机气溶胶(SOA)对污染源的贡献。在克利夫兰，初级来源占环境有机碳的37+/-2%，测量的生物和人为次要来源占46+/-6%，其他未知来源占17+/-4%。同样，底特律的气溶胶被确定为44+/-5%的初级气溶胶和37+/-3%的次要气溶胶，而19+/-7%的气溶胶没有被测量到的来源解释。在河滨，21+/-3%的有机碳来自初级来源，26+/-5%归因于测量的二级来源，53+/-3%来自其他预计为次要来源的来源。这两个地区的样本比较表明，美国中西部夏季的SOA与洛杉矶空气盆地的夏季SOA有很大不同，并表明在总结不同城市地区的SOA来源和性质时需要谨慎。此外，这项研究的结果表明，当代对SOA源和形成机制的理解是令人满意的，可以解释中西部的大部分SOA源和形成机制，需要额外的SOA源和形成机制来解释洛杉矶气盆的大部分SOA源和形成机制。
Primary and secondary sources contributing to atmospheric organic aerosol during the months of July and August were quantitatively assessed in three North American urban areas: Cleveland, Ohio, and Detroit, Michigan, in the Midwest region and Riverside, California, in the Los Angeles Air Basin. Organic molecular marker species unique to primary aerosol sources and secondarytracers derived from isoprene, alpha-pinene, beta-caryophyllene, and toluene were measured using gas chromatography-mass spectrometry. Source contributions from motor vehicles, biomass burning, vegetative detritus, and secondary organic aerosol (SOA) were estimated using chemical mass balance (CMB) modeling. In Cleveland, primary sources accounted for 37 +/- 2% of ambient organic carbon, measured biogenic and anthropogenic secondary sources contributed 46 +/- 6%, and other unknown sources contributed 17 +/- 4%. Similarly, Detroit aerosol was determined to be 44 +/- 5% primary and 37 +/- 3% secondary, while 19 +/- 7% was unaccounted for by measured sources. In Riverside, 21 +/- 3% of organic carbon came from primary sources, 26 +/- 5% was attributed to measured secondary sources, and 53 +/- 3% came from other sources that were expected to be secondary in nature. The comparison of samples across these two regions demonstrated that summertime SOA in the Midwestern United States was substantially different from the summertime SOA in the Los Angeles Air Basin and indicated the need to exert caution when generalizing about the sources and nature of SOA across different urban areas. Furthermore, the results of this study suggestthatthe contemporary understanding of SOA sources and formation mechanisms is satisfactory to explainthe majority of SOA in the Midwest Additional SOA sources and mechanisms of formation are needed to explain the majority of SOA in the Los Angeles Air Basin.