Eleven particle samples collected in the polar stratosphere during SOLVE (SAGE III Ozone loss and validation experiment) from January until March 2000 were characterized in detail by high-resolution transmission and scanning electron microscopy (TEM/SEM) combined with energy-dispersive X-ray microanalysis. A total of 4202 particles (TEM??=??3872; SEM??=??330) were analyzed from these samples, which were collected mostly inside the polar vortex in the altitude range between 17.3 and 19.9?km. Particles that were volatile in the microscope beams contained ammonium sulfates and hydrogen sulfates and dominated the samples. Some particles with diameters ranging from 20 to 830?nm were refractory in the electron beams. Carbonaceous particles containing additional elements to C and O comprised from 72 to 100?% of the refractory particles. The rest were internal mixtures of these materials with sulfates. The median number mixing ratio of the refractory particles, expressed in units of particles per milligram of air, was 1.1?(mg?air)sup?1/sup and varied between 0.65 and 2.3?(mg?air)sup?1/sup. brbr Most of the refractory carbonaceous particles are completely amorphous, a few of the particles are partly ordered with a graphene sheet separation distance of 0.37?±?0.06?nm (mean value?±?standard deviation). Carbon and oxygen are the only detected major elements with an atomic O∕C ratio of 0.11?±?0.07. Minor elements observed include Si, S, Fe, Cr and Ni with the following atomic ratios relative to C: Si∕C: 0.010?±?0.011; S∕C: 0.0007?±?0.0015; Fe∕C: 0.0052?±?0.0074; Cr∕C: 0.0012?±?0.0017; Ni∕C: 0.0006?±?0.0011 (all mean values?±?standard deviation).High-resolution element distribution images reveal that the minor elements are distributed within the carbonaceous matrix; i.e., heterogeneous inclusions are not observed. No difference in size, nanostructure and elemental composition was found between particles collected inside and outside the polar vortex. brbr Based on chemistry and nanostructure, aircraft exhaust, volcanic emissions and biomass burning can certainly be excluded as sources. The same is true for the less probable but globally important sources: wood burning, coal burning, diesel engines and ship emissions. brbr Recondensed organic matter and extraterrestrial particles, potentially originating from ablation and fragmentation, remain as possible sources of the refractory carbonaceous particles studied. However, additional work is required in order to identify the sources unequivocally.
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机译：通过高分辨率透射和扫描电子显微镜（TEM / SEM）结合能量色散X射线对SOLVE（SAGE III臭氧损失和验证实验）期间从极地平流层收集的11个粒子样品进行了详细表征微量分析。从这些样品中总共分析了4202个颗粒（TEMδ= 3872; SEMδ= 330），这些颗粒主要收集在极涡内部，高度范围为17.3-19.9 km。在显微镜光束中易挥发的颗粒包含硫酸铵和硫酸氢盐，并主导了样品。一些直径在20到830？nm范围内的粒子在电子束中是难熔的。含碳和氧额外元素的碳质颗粒占耐火颗粒的72％至100％。其余为这些物质与硫酸盐的内部混合物。耐火颗粒的中位数混合比，以每毫克空气中的颗粒单位表示，为1.1？（mg？air）？1 ，且在0.65至2.3？（mg？air）< sup>？1 。 大多数耐火碳质颗粒是完全无定形的，部分颗粒是有序排列的，石墨烯片的分离距离为0.37？±？0.06？nm（均值？±？标准差）。碳和氧是仅有的检测到的主要O O原子比为0.11≤±0.07的主要元素。观察到的微量元素包括Si，S，Fe，Cr和Ni，相对于C的原子比为：Si ∕ C：0.010±±0.011。 S ∕ C：0.0007±0.0015。 Fe ∕ C：0.0052±±0.0074。 Cr ∕ C：0.0012±±0.0017。 Ni ∕ C：0.0006≤±0.0011（所有平均值≤±标准偏差）。高分辨率元素分布图显示，微量元素分布在碳质基质中;即，未观察到异质夹杂物。在极涡内部和外部收集的颗粒之间没有发现大小，纳米结构和元素组成的差异。 基于化学和纳米结构，可以肯定地排除了飞机排气，火山排放和生物质燃烧。对于可能性较小但在全球范围内重要的排放源也是如此：木材燃烧，燃煤，柴油发动机和船舶排放。 可能源自消融和破碎的缩聚有机物和地外颗粒仍然是研究的耐火碳质颗粒的可能来源。但是，需要进行额外的工作才能明确识别来源。
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