Aerosol properties, source identification, and cloud processing in orographic clouds measured by single particle mass spectrometry on a central European mountain site during HCCT-2010
Aerosol properties, source identification, and cloud processing in orographic clouds measured by single particle mass spectrometry on a central European mountain site during HCCT-2010
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DOI：
10.5194/acp-16-505-2016
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发表时间：
2015-09
影响因子：
6.3
通讯作者：
A. Roth;J. Schneider;T. Klimach;S. Mertes;D. Pinxteren;H. Herrmann;S. Borrmann
中科院分区：
文献类型：
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作者：
A. Roth;J. Schneider;T. Klimach;S. Mertes;D. Pinxteren;H. Herrmann;S. Borrmann
抽象的。2010年9月至10月，在为期6周的“图林根州山顶云”（HCCT）-2010研究期间，通过在线单粒子气溶胶质谱法分析了直径在150至900 nm之间的云残留物和云外气溶胶粒子。测量地点是Schmucke山（海拔937米）。在德国中部。获得了160 000多个来自云外气溶胶粒子的双极质谱和13 000多个来自云残留粒子的双极质谱，并使用模糊c均值聚类算法进行分类。通过将聚类输出与操作员逐个颗粒的检查和分类进行比较，对数据子集进行分类算法的不确定性分析。该分析产生了13%至48%的错误分类概率。此外，颗粒类型还通过特定的标记离子来识别。从环境气溶胶分析的结果表明，63%的分析颗粒属于具有昼夜变化的集群，这表明本地或区域源占主导地位的气溶胶，特别是含有烟尘和生物质燃烧颗粒的颗粒。在云残留物中，大的含烟颗粒和含胺颗粒的相对百分比被发现增加相比，云外气溶胶，而在一般情况下，有机颗粒在云残留物中的丰度较低。在胺的情况下，这可以通过胺的高溶解度来解释，而大的含烟颗粒被发现与无机物内部混合，这解释了它们作为云凝结核的活化。此外，结果表明，在云处理过程中，硫酸盐和硝酸盐都被添加到残留粒子中，从而改变了混合状态，并增加了具有硝酸盐和/或硫酸盐的粒子的分数。预计这将导致云蒸发后更高的吸湿性，从而增加粒子在云通过后作为云凝结核的能力。
Abstract. Cloud residues and out-of-cloud aerosol particles with diameters between 150 and 900 nm were analysed by online single particle aerosol mass spectrometry during the 6-week study Hill Cap Cloud Thuringia (HCCT)-2010 in September–October 2010. The measurement location was the mountain Schmucke (937 m a.s.l.) in central Germany. More than 160 000 bipolar mass spectra from out-of-cloud aerosol particles and more than 13 000 bipolar mass spectra from cloud residual particles were obtained and were classified using a fuzzy c-means clustering algorithm. Analysis of the uncertainty of the sorting algorithm was conducted on a subset of the data by comparing the clustering output with particle-by-particle inspection and classification by the operator. This analysis yielded a false classification probability between 13 and 48 %. Additionally, particle types were identified by specific marker ions. The results from the ambient aerosol analysis show that 63 % of the analysed particles belong to clusters having a diurnal variation, suggesting that local or regional sources dominate the aerosol, especially for particles containing soot and biomass burning particles. In the cloud residues, the relative percentage of large soot-containing particles and particles containing amines was found to be increased compared to the out-of-cloud aerosol, while, in general, organic particles were less abundant in the cloud residues. In the case of amines, this can be explained by the high solubility of the amines, while the large soot-containing particles were found to be internally mixed with inorganics, which explains their activation as cloud condensation nuclei. Furthermore, the results show that during cloud processing, both sulfate and nitrate are added to the residual particles, thereby changing the mixing state and increasing the fraction of particles with nitrate and/or sulfate. This is expected to lead to higher hygroscopicity after cloud evaporation, and therefore to an increase of the particles' ability to act as cloud condensation nuclei after their cloud passage.