A study of the mixing state of black carbon in urban zone
A study of the mixing state of black carbon in urban zone
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DOI：
10.1029/2003jd003940
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发表时间：
2004-02
影响因子：
--
通讯作者：
M. Mallet;J. Roger;S. Despiau;J. Putaud;O. Dubovik
中科院分区：
文献类型：
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作者：
M. Mallet;J. Roger;S. Despiau;J. Putaud;O. Dubovik
[1]黑碳颗粒与其他气溶胶种类的混合状态的知识是黑碳颗粒的直接辐射效应及其对气候的影响的充分模拟的关键。本文报道了城市地区黑碳气溶胶混合状况的调查。该研究采用了在ESCompte实验，这发生在2001年夏天在法国的工业化地区进行的现场和地面遥感观测相结合。我们用于识别混合状态的标准依赖于已知的增强吸收的气溶胶组成的内部与外部的黑碳与弱吸收气溶胶组分的混合物。首先，使用原位气溶胶数据，我们进行了米氏计算和重建的单散射的气溶胶的两种不同的混合假设：黑碳混合外部或内部与其他气溶胶物种。然后，我们比较了所获得的值ωo，int和ωo，ext与独立AERONET太阳光度测量的ωo的检索。气溶胶单次散射能谱（ωo，aer.）AERONET光度计观测值（平均值为0.84 ± 0.04）的ω o，ext与现场观测值在外部混合假设下重建的ωo，ext接近。AERONET值和外部混合物模拟之间的这种相似性在研究的所有日子都观察到。我们的结论与其他独立的研究报告在最近的一些出版物中所作的观察在ESCompte期间（接近污染源）在城市地区的黑碳气溶胶与其他颗粒的外部混合物是一致的。
[1] The knowledge of the mixing state of black carbon particle with other aerosol species is critical for adequate simulations of the direct radiative effect of black carbon particles and its effect on climate. This paper reports the investigation of the mixing state of black carbon aerosol in the urban zone. The study uses a combination of in situ and ground-based remote sensing observations conducted during the ESCOMPTE experiment, which took place in industrialized region in France in summer of 2001. The criteria we used for identifying mixing state relies on the known enhancement of absorption for aerosol composed by internal versus external mixtures of black carbon with weakly absorbing aerosol components. First, using in situ aerosol data, we performed Mie computations and reconstructed the single scattering albedo of aerosol for the two different mixing assumptions: black carbon mixed externally or internally with other aerosol species. Then, we compared the obtained values ωo,int and ωo,ext with the retrievals of ωo from independent AERONET Sun-photometric measurements. The aerosol single scattering albedo (ωo,aer.) derived from the AERONET photometer observations (with the mean value equal to 0.84 ± 0.04) was found to be close to ωo,ext reconstructed from in situ observation under assumptions of external mixture. This similarity between AERONET values and external mixture simulations was observed during all the days studied. Our conclusion on external mixture of black carbon aerosol with other particles in urban zone during ESCOMPTE (close to the pollution source) is coherent with observations made during other independent studies reported in a number of recent publications.