当前位置: X-MOL 学术ACS Earth Space Chem. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Optical Characterization of Mineral Dust from the EAIIST Project with Digital Holography
ACS Earth and Space Chemistry ( IF 3.4 ) Pub Date : 2021-09-01 , DOI: 10.1021/acsearthspacechem.1c00224
Claudia Ravasio 1 , Llorenç Cremonesi 1 , Claudio Artoni 2, 3 , Barbara Delmonte 2 , Valter Maggi 2, 4 , Marco A. C. Potenza 1, 5
Affiliation  

We describe an optical approach based on Digital Holography for single-particle characterization of mineral dust and micrometric particles, focusing on the analysis of airborne particles in meltwater from Antarctic ice cores. We record the holograms formed by the superposition of the transilluminating reference beam and the waves scattered by single particles. Taking a cue from recent approaches in the field and holography methods, we process the holograms to recover both optical and morphological properties of single dust grains. As a considerable advantage over traditional light-scattering-based methods, holograms give the extinction cross section of each particle and, by numerically reconstructing the wavefront propagation, an unambiguous image of each particle whereby we derive its cross-sectional shape and size. Measurements have been carried out on samples collected from the recent EAIIST (East Antarctic International Ice Sheet Traverse) project, some of which show evidence of volcanic events. The vast majority of the detected particles show significant deviations from the isometric shape, as confirmed by both image reconstruction and extinction cross section analysis. By our analysis, we observe that experimental data have an extinction cross section up to 3 times lower than that of spherical particles with the same volume. Therefore, these deviations have an appreciable impact on the aerosol contribution to radiative forcing: retrieving particle shape may improve the modeling of the radiative properties of mineral dust and reduce the associated uncertainties.

中文翻译:

使用数字全息技术对来自 EAIIST 项目的矿物粉尘进行光学表征

我们描述了一种基于数字全息术的光学方法,用于矿物粉尘和微米颗粒的单颗粒表征,重点是分析南极冰芯融水中的空气颗粒。我们记录了由透照参考光束和单个粒子散射的波叠加形成的全息图。从该领域的最新方法和全息方法中汲取灵感,我们处理全息图以恢复单个尘埃颗粒的光学和形态特性。与传统的基于光散射的方法相比,全息图具有相当大的优势,它给出了每个粒子的消光截面,并通过数值重建波前传播,给出了每个粒子的明确图像,由此我们得出了其截面形状和大小。对从最近的 EAIIST(东南极国际冰盖穿越)项目收集的样本进行了测量,其中一些显示了火山事件的证据。正如图像重建和消光横截面分析所证实的那样,绝大多数检测到的粒子显示出与等距形状的显着偏差。通过我们的分析,我们观察到实验数据的消光截面比相同体积的球形颗粒低3倍。因此,这些偏差对气溶胶对辐射强迫的贡献具有显着影响:检索颗粒形状可以改进矿物粉尘辐射特性的建模并减少相关的不确定性。
更新日期:2021-10-22
down
wechat
bug