Abstract

The aim of this study was to explore particle size dependent properties by combining long-term observations of equivalent black carbon (eBC) and number size distributions to investigate their correlation as function of particle size. The work was conducted in two main parts. The first part consisted of a short laboratory experiment to compare observed total particle light absorption (σ_abs) with that observed according to particle size by using a combination of a Differential Mobility Analyzer (DMA) and a Particle Soot Absorption Photometer (PSAP). The laboratory study confirmed strong similarities between the observed and derived σ_abs. In the second part the statistical approach using correlation between the σ_abs and the dN of each bin of the number size distribution was tested on long-term data ranging from 2002 to 2010 observed at Zeppelin station, Ny-Ålesund Svalbard. The data was clustered according to the number size distribution and grouped in four major categories: Washout, Nucleation, Intermediate and Polluted. Each category presented different features with respect to the derived eBC mass distributions, the Intermediate category showed similarities to the few available Single Particle Soot Photometer (SP2) observations in the Arctic. Overall, the statistical distribution of eBC, according to particle size, presented a larger dynamical range in the location of the mode(s). To check for consistency, the eBC mass distributions were transformed into number based eBC size distribution and compared to the observed total number size distribution. Whereas the Washout, Nucleation and Intermediate categories presented plausible number distributions, the Polluted category displayed a mode at small sizes (about 50 nm) that was significantly exaggerated.

摘要

本研究的目的是通过结合当量黑碳 (eBC) 和数量尺寸分布的长期观察结果来研究它们与粒径函数的相关性，从而探索粒径相关特性。这项工作分两个主要部分进行。第一部分包括一个简短的实验室实验，通过使用微分迁移率分析仪 (DMA) 和颗粒烟灰吸收光度计 (PSAP) 的组合，将观察到的总粒子光吸收 (σ _abs ) 与根据粒径观察到的进行比较。实验室研究证实了观察到的和导出的 σ _abs之间有很强的相似性。在第二部分中，使用 σ _abs之间的相关性的统计方法数字大小分布的每个区间的 dN 是根据 2002 年至 2010 年在 Ny-Ålesund Svalbard 齐柏林站观测到的长期数据进行测试的。数据根据数量大小分布进行聚类，并分为四大类：冲刷、成核、中间和污染。每个类别在导出的 eBC 质量分布方面表现出不同的特征，中间类别与北极地区少数可用的单粒子烟尘光度计 (SP2) 观测结果相似。总体而言，eBC 的统计分布（根据粒径）在模式位置呈现更大的动态范围。为了检查一致性，将 eBC 质量分布转换为基于数量的 eBC 大小分布，并与观察到的总数大小分布进行比较。