Testing Iron Stable Isotope Ratios as a Signature of Biomass Burning
Testing Iron Stable Isotope Ratios as a Signature of Biomass Burning
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测试铁稳定同位素比率作为生物质燃烧的特征标识
DOI：
10.3390/atmos10020076
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发表时间：
2019-02
期刊：
影响因子：
2.9
通讯作者：
Minako Kurisu;Y. Takahashi
中科院分区：
文献类型：
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作者：
Minako Kurisu;Y. Takahashi
生物质燃烧是一个重要来源的可溶性铁运输到公海，但其确切的贡献仍然不清楚。铁同位素比可以用作示踪剂，因为燃烧排放的Fe由于蒸发过程中的同位素分馏而可以产生非常低的Fe同位素比。然而，缺乏生物质燃烧过程中排放的气溶胶颗粒的铁同位素比的数据。我们收集了大小分级的气溶胶样品之前，期间和之后的生物质燃烧事件，并比较其铁同位素比值。根据几种元素和铁的物种的浓度，在事件中排放的铁主要包括悬浮的土壤颗粒在所有的尺寸级。受其他人为燃烧源的影响，事件前后细颗粒物的铁同位素比值较低，但受悬浮土中Fe的影响，事件期间细颗粒物的铁同位素比值更接近地壳值。虽然可溶性铁的铁同位素比值也进行了测量，以减少铁从土壤成分，我们没有发现低的同位素信号。结果表明，铁同位素比值不能识别生物质燃烧排放的铁，低的铁同位素比值被发现只有当燃烧温度足够高，足够量的铁蒸发。
Biomass burning is an important source of soluble Fe transported to the open ocean; however, its exact contribution remains unclear. Iron isotope ratios can be used as a tracer because Fe emitted by combustion can yield very low Fe isotope ratios due to isotope fractionation during evaporation processes. However, data on Fe isotope ratios of aerosol particles emitted during biomass burning are lacking. We collected size-fractionated aerosol samples before, during, and after a biomass burning event and compared their Fe isotope ratios. On the basis of the concentrations of several elements and Fe species, Fe emitted during the event mainly comprised suspended soil particles in all the size fractions. Iron isotope ratios of fine particles before and after the event were low due to the influence of other anthropogenic combustion sources, but they were closer to the crustal value during the event because of the influence of Fe from suspended soil. Although Fe isotope ratios of soluble Fe were also measured to reduce Fe from soil components, we did not find low isotope signals. Results suggested that Fe isotope ratios could not identify Fe emitted by biomass burning, and low Fe isotope ratios are found only when the combustion temperature is high enough for a sufficient amount of Fe to evaporate.