Atmospheric tar balls from biomass burning in Mexico
Atmospheric tar balls from biomass burning in Mexico
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DOI：
10.1029/2010jd015102
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发表时间：
2011-03-08
影响因子：
4.4
通讯作者：
Buseck, Peter R.
中科院分区：
文献类型：
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作者：
Adachi, Kouji;Buseck, Peter R.
大气焦油球（TBs）是在生物质燃烧（BB）产生的烟雾中产生的球形有机气溶胶颗粒。它们吸收阳光，从而导致大气变暖。本研究报告了一项透射电子显微镜（TEM）研究，从墨西哥热带地区排放的几分钟到几小时内收集的BB烟雾样本中提取TBs。在扫描电子显微镜图像和电子断层扫描中可以看到它们的球形，表明它们在收集时是固体的。它们由C和小O、S、K和n组成。在相对湿度为100%时，我们相对新鲜的TBs的吸湿生长因子为1.09 +/- 0.04。在距离火场< 0.6 km和> 1.6 km的样品中，空气动力学直径为50 ~ 300 nm的颗粒中，TBs的平均含量分别为1%和14%。后者年龄较大，其总体积约为烟灰的两倍，其在550 nm波长处计算的总光吸收率为烟灰的74 - 96%，具体吸收率取决于烟灰的大小、形状和涂层。总的来说，我们分析的结核在大小、外部混合、包裹体的相对自由度和组成方面与北美、南部非洲和欧洲的结核相似。这项研究和以前的研究表明，TBs是由一系列生物质燃料引起的。它们在全球不同地区的分布，再加上它们的光学特性，表明它们对区域甚至全球气候都有重要影响。
Atmospheric tar balls (TBs) are spherical, organic aerosol particles that occur in smoke from biomass burning (BB). They absorb sunlight and thereby cause warming of the atmosphere. This study reports a transmission electron microscope (TEM) study of TBs from BB smoke samples collected within minutes to hours from emission in a tropical area of Mexico. Their spherical shapes as seen in both scanning electron microscope images and with electron tomography indicate that they were solid when collected. They consist of C and minor O, S, K, and N. The hygroscopic growth factor for our relatively fresh TBs is 1.09 +/- 0.04 at a relative humidity of 100%. In samples < 0.6 km and > 1.6 km from the fire, an average of similar to 1 and 14%, respectively, of particles with aerodynamic diameter from 50 to 300 nm consisted of TBs. For the latter, more aged samples, the total volume was roughly double that of soot, and their total calculated light absorption at a wavelength of 550 nm was between 74 and 96% that of soot, with the exact amount depending on the size, shape, and coating of the soot. In general, the TBs that we analyzed were similar to those from North America, southern Africa, and Europe in terms of size, external mixing, relative freedom of inclusions, and composition. This and previous studies show that TBs result from a range of biomass fuels. Their distribution from various regions across the globe, combined with their optical properties, suggests they have important effects on regional and perhaps global climate.