Seasonal trends and possible sources of brown carbon based on 2-year aerosol measurements at six sites in Europe
Seasonal trends and possible sources of brown carbon based on 2-year aerosol measurements at six sites in Europe
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DOI：
10.1029/2006jd008151
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发表时间：
2007-12
影响因子：
--
通讯作者：
H. Lukács;A. Gelencser;S. Hammer;H. Puxbaum;C. Pio;M. Legrand;A. Kasper-Giebl;M. Handler;A. L
中科院分区：
文献类型：
--
作者：
H. Lukács;A. Gelencser;S. Hammer;H. Puxbaum;C. Pio;M. Legrand;A. Kasper-Giebl;M. Handler;A. L
棕色碳是有机气溶胶中普遍存在的未知成分，近年来已成为大气研究的前沿。这一成分与气溶胶中腐殖质类物质（HULIS）密切相关，后者的最终来源仍在争论中。用简化的光谱方法测定了在CARBOSOL项目中收集的细气溶胶的水萃取物中棕色碳的浓度。根据对欧洲6个地点的几种气溶胶成分的2年测量结果，推断出棕色碳的可能来源。生物质燃烧（可能是家庭木材燃烧）被证明是冬季棕色碳的主要来源。在春季的高架地区，农业火灾产生的烟雾可能是另一个来源。将测量到的棕色碳浓度与由一种独立方法确定的HULIS直接比较表明，这两个量在全年的低海拔地区具有良好的相关性。在高海拔地区，相关性在冬季仍然很高，但在夏季明显降低，这意味着棕色碳和HULIS的来源和/或大气汇不同。研究结果揭示了大气棕色碳和有机气溶胶中两个定义不清且重叠的成分HULIS之间的关系。
Brown carbon is a ubiquitous and unidentified component of organic aerosol which has recently come into the forefront of atmospheric research. This component is strongly linked to the class of humic-like substances (HULIS) in aerosol whose ultimate origin is still being debated. Using a simplified spectroscopic method the concentrations of brown carbon have been determined in aqueous extracts of fine aerosol collected during the CARBOSOL project. On the basis of the results of 2-year measurements of several aerosol constituents at six European sites, possible sources of brown carbon are inferred. Biomass burning ( possibly domestic wood burning) is shown to be a major source of brown carbon in winter. At elevated sites in spring, smoke from agricultural fires may be an additional source. Direct comparison of measured brown carbon concentrations with HULIS determined by an independent method reveals that the two quantities correlate well at low-elevation sites throughout the year. At high-elevation sites the correlation is still high for winter but becomes markedly lower in summer, implying different sources and/or atmospheric sinks of brown carbon and HULIS. The results shed some light on the relationships between atmospheric brown carbon and HULIS, two ill-defined and overlapping components of organic aerosol.