Determination and analysis of in situ spectral aerosol optical properties by a multi-instrumental approach
Determination and analysis of in situ spectral aerosol optical properties by a multi-instrumental approach
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DOI：
10.5194/amt-7-2373-2014
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发表时间：
2014-08
影响因子：
3.8
通讯作者：
S. Segura;V. Estellés;G. Titos;H. Lyamani;M. P. Utrillas;P. Zotter;A. Prévôt;G. Močnik;L. Alados-Arboledas;J. Martínez-Lozano
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作者：
S. Segura;V. Estellés;G. Titos;H. Lyamani;M. P. Utrillas;P. Zotter;A. Prévôt;G. Močnik;L. Alados-Arboledas;J. Martínez-Lozano
抽象的。2012年6月29日至7月29日在西班牙格拉纳达使用七波长浊度计、多角度吸收光度计和三波长积分浊度计对气溶胶光学特性进行了连续原位测量。这项工作的目的是描述一种方法来获得不同的Aethalometer波长的吸收系数（babs）。以这种方式，使用最佳估计所需补偿因子的算法来补偿数据。使用两个经验因子来从Aethalometer测量推断吸收系数：C -描述由于滤光器基质中的光的多次散射而导致的滤光器基质中的颗粒的吸收增强的参数-和f，补偿滤光器基质中的非线性负载效应的参数。本研究发现f的光谱依赖性不是很强。该活动的值在370 nm处的1.15至950 nm处的1.11的范围内。C中的波长依赖性被证明更重要，也更难以计算。所获得的值范围为370 nm处的3.42至950 nm处的4.59。此外，给出了吸收的Angstrom指数（αabs）和单次散射的Angstrom指数（ω0）随时间的演化。在370和950 nm处，平均αabs约为1.1 ± 0.3，ω0分别为0.78 ± 0.08和0.74 ± 0.09。这些都是典型的吸收颗粒占主导地位的网站，在这项研究中的城市测量网站是这样的。babs平均值分别为16 ± 10 Mm−1（370 nm）和5 ± 3 Mm−1（950 nm）。最后，进一步分析了工作日和周日之间的差异，由于柴油交通的影响，工作日期间比周日获得更高的babs和更低的ω0。
Abstract. Continuous in situ measurements of aerosol optical properties were conducted from 29 June to 29 July 2012 in Granada (Spain) with a seven-wavelength Aethalometer, a Multi-Angle Absorption Photometer, and a three-wavelength integrating nephelometer. The aim of this work is to describe a methodology to obtain the absorption coefficients (babs) for the different Aethalometer wavelengths. In this way, data have been compensated using algorithms which best estimate the compensation factors needed. Two empirical factors are used to infer the absorption coefficients from the Aethalometer measurements: C – the parameter describing the enhancement of absorption by particles in the filter matrix due to multiple scattering of light in the filter matrix – and f, the parameter compensating for non-linear loading effects in the filter matrix. Spectral dependence of f found in this study is not very strong. Values for the campaign lie in the range from 1.15 at 370 nm to 1.11 at 950 nm. Wavelength dependence in C proves to be more important, and also more difficult to calculate. The values obtained span from 3.42 at 370 nm to 4.59 at 950 nm. Furthermore, the temporal evolution of the Angstrom exponent of absorption (αabs) and the single-scattering albedo (ω0) is presented. On average αabs is around 1.1 ± 0.3, and ω0 is 0.78 ± 0.08 and 0.74 ± 0.09 at 370 and 950 nm, respectively. These are typical values for sites with a predominance of absorbing particles, and the urban measurement site in this study is such. The babs average values are of 16 ± 10 Mm−1 (at 370 nm) and 5 ± 3 Mm−1 (at 950 nm), respectively. Finally, differences between workdays and Sundays have been further analysed, obtaining higher babs and lower ω0 during the workdays than on Sundays as a consequence of the diesel traffic influence.