Enhanced modern carbon and biogenic organic tracers in Northeast Asian aerosols during spring/summer
Enhanced modern carbon and biogenic organic tracers in Northeast Asian aerosols during spring/summer
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DOI：
10.1002/jgrd.50244
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发表时间：
2013-03
期刊：
影响因子：
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通讯作者：
C. Pavuluri;K. Kawamura;M. Uchida;M. Kondo;P. Fu
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文献类型：
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作者：
C. Pavuluri;K. Kawamura;M. Uchida;M. Kondo;P. Fu
为了更好地了解东北亚地区有机气溶胶(OA)的来源和形成过程，我们对日本北部札幌市1年多的大气气溶胶(TSP)样品进行了研究，以测定气溶胶总碳(TC)和水溶性有机碳(WSOC)中的放射性碳(14C)。我们还测量了各种有机示踪剂和含碳成分：有机碳(OC)、WSOC和元素碳(EC)。我们发现，现代碳(PMC)在TC和WSOC中的百分比在春夏季有所增加，最大值(分别为85%和117%)出现在5月份。WSOC和TC中PMC的时间变化与生物来源的OA示踪剂对OC和WSOC贡献的变化具有很好的一致性。我们还发现，春季花粉的释放和夏秋季土壤真菌孢子的释放以及夏秋季生物来源VOCs(BVOCs)的次生OA的形成是导致PMC增加的原因。尽管生物质燃烧的排放量在冬季很大，但加强化石燃料燃烧会降低WSOC和TC中的PMC。在全年中，现代碳在WSOC组分中比在TC中更富集，表明WSOC与生物活性更相关。考虑到BVOC排放的季节差异，特别是在温带地区，这项研究证明有必要协调大气模型，以估计OA二次预算及其气候影响。
To better understand the organic aerosol (OA) sources and formation processes in Northeast Asia, we studied atmospheric aerosol (total suspended particulate matter (TSP)) samples collected from Sapporo, northern Japan over 1 year period for the measurement of radiocarbon (14C) in aerosol total carbon (TC) and water‐soluble organic carbon (WSOC). We also measured various organic tracers and carbonaceous components: organic carbon (OC), WSOC, and elemental carbon (EC). We found that the percent modern carbon (pMC) in TC and WSOC increased during spring/summer with maximum (85% and 117%, respectively) in May. The temporal variations of pMC in WSOC and TC showed a good agreement with changes in the contributions of biogenic OA tracers to OC and WSOC. We also found that emissions of pollen in spring and fungal spores from soil in summer/autumn as well as secondary OA formation from biogenic VOCs (BVOCs) in summer/autumn are responsible for the enhanced pMC. Although emissions from biomass burning are significant in winter, enhanced fossil fuel combustion lowers the pMC in WSOC and TC. Throughout the year, modern carbon is more enriched in WSOC fraction than in TC, indicating that WSOC is more associated with biological activity. This study warrants a need to reconcile the atmospheric models, considering seasonal differences in BVOC emissions, particularly in temperate regions, in estimating secondary OA budget and its climatic impacts.