Download or read book Investigations of Angular Light Scattering by Complex Atmospheric Particles written by Jaervinen, Emma and published by KIT Scientific Publishing. This book was released on 2016-11-21 with total page 258 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book experimentally investigates the angular light scattering properties of three atmospherically relevant particles: ice crystals, dust particles and secondary organic aerosol particles. Key optical quantities under examination are the near-backscattering depolarisation properties and the angular light scattering function. The main question is how these parameters are related to the particle microphysical properties, such as particle size and complexity.
Download or read book Investigations of Angular Light Scattering by Complex Atmospheric Particles written by Emma Järvinen and published by . This book was released on 2020-10-09 with total page 256 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book experimentally investigates the angular light scattering properties of three atmospherically relevant particles: ice crystals, dust particles and secondary organic aerosol particles. Key optical quantities under examination are the near-backscattering depolarisation properties and the angular light scattering function. The main question is how these parameters are related to the particle microphysical properties, such as particle size and complexity. This work was published by Saint Philip Street Press pursuant to a Creative Commons license permitting commercial use. All rights not granted by the work's license are retained by the author or authors.
Download or read book Light Scattering by Irregularly Shaped Particles written by Schuerman and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 335 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume contains most of the invited papers presented at the International Workshop on Light Scattering by Irregularly Shaped Particles held on June 5-7, 1979. at the State University of New York at Albany (SUNYA). Over seventy participants representing many dis ciplines convened to define some of the ever-increasing number of resonant light-scattering problems associated with particle shape and to relate their most recent investigations in this field. It is obvious from the two introductory papers that an investi gator's primary discipline determines his/her approach to the light scattering problem. The meteorologist, Diran Deirmendjian, advocates an empirical methodology: to model the scattering by atmospheric aerosols, using equivalent spheres as standards, in the most effi cient and simplest manner that is consistent with remote sensing, in situ, and laboratory· data. Because of the almost infinite variety of particle shapes, he questions not only the possibility but even the usefulness of the exact solution of scattering by a totally arbitrary particle. The astrophysicist, J. Mayo Greenberg, is primarily concerned with the information content carried by the scattered light because this radiation is the sole clue to under standing the nature of interstellar dust. What measurements (polar ization, color dependence, etc ••• ) should be made to best determine a given particle characteristic (size, surface roughness, refractive index, etc ••• )? Thus, he considers the physics of the scattering process to be of paramount interest.
Download or read book Numerical Investigation of Light Scattering by Atmospheric Particles written by Chao Liu and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Atmospheric particles, i.e. ice crystals, dust particles, and black carbon, show significant complexities like irregular geometries, inhomogeneity, small-scale surface structures, and play a significant role in the atmosphere by scattering and absorbing the incident solar radiation and terrestrial thermal emission. Knowledge of aerosol scattering properties is a fundamental but challenging aspect of radiative transfer studies and remote sensing applications. This dissertation tries to improve our understanding on the scattering properties of atmospheric particles by investigating both the scattering algorithms and the representation of the realistic particles. One part of this dissertation discusses in details the pseudo-spectral time domain algorithm (PSTD) for calculating scattering properties, its advantages and the elimination of the Gibbs phenomenon. The applicability of the parallelized PSTD implementation is investigated for both spherical and nonspherical particles over a wide range of sizes and refractive indices, and the PSTD is applied for spherical particles with size parameters up to 200, and randomly oriented non-spherical ones with size parameters up to 100. The relative strengths of the PSTD are also shown by a systematic comparison with the discrete dipole approximation (DDA). The PSTD outperforms the DDA for particles with refractive indices larger than 1.4, and ones with smaller refractive indices by large sizes (e.g. size parameters larger than 60 for a refractive index of 1.2). The results suggest significant potential of the PSTD for the numerical investigation of the light scattering and corresponding atmospheric applications. The other part of this dissertation investigates the effects of particle complexities on the light scattering properties of the atmospheric particles, and three aspects corresponding to the irregular geometry, inhomogeneity and surface roughness are studied. To cover the entire particle size range from the Rayleigh to the geometric- optics regimes, the PSTD (for relatively small particles) is combined with the im- proved geometric-optics method (IGOM) that is only applicable for large particles. The Koch-fractal geometry is introduced to model the light scattering properties of aerosol, and performs an excellent job of reproducing the experimental measurements of various mineral dust particles. For the inhomogeneous particles, the applicability of the effective medium approximations (EMA) is tested, and the EMA can be used to approximate the scattering properties of inhomogeneous particles only when the particles are uniformly internal mixtures. Furthermore, an irregular rough model is developed to study the effects of the small-scale surface roughness on the light scattering properties. In conclusion, the dissertation finds that the complexities of atmospheric particles have to be fully considered to obtain their scattering properties accurately. The electronic version of this dissertation is accessible from http://hdl.handle.net/1969.1/151138
Download or read book Springer Series in Light Scattering written by Alexander Kokhanovsky and published by Springer Nature. This book was released on 2021-10-27 with total page 165 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book aims to the description of recent progress in studies of light absorption and scattering in turbid media. In particular, light scattering/oceanic optics/snow optics research community will greatly benefit from the publication of this book.
Download or read book Light Scattering From Micrometric Mineral Dust and Aggregate Particles written by Llorenç Cremonesi and published by Springer Nature. This book was released on 2020-09-24 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt: Light scattering from particles in the nanometric and micrometric size range is relevant in several research fields, such as aerosol science and nanotechnology. In many applications, the description of the optical properties of non-spherical, inhomogeneous particles is still inadequate or requires demanding numerical calculations. Lorenz–Mie scattering and effective medium approximations represent currently the main theoretical tools to model such particles, but their effectiveness has been recently called into question. This work examines how the morphology of a particle affects its scattering parameters from an experimental standpoint, supporting findings with extensive simulations. The dust content of Antarctic, Greenlandic, and Alpine ice cores is analysed with a particle-by-particle approach. Moreover, a study on colloidal aggregates shows that correlations among the fields radiated by primary particles are responsible for the poor agreement of effective medium approximations with experimental results. On the theoretical side, an interpretation in terms of the structure factor is given, which satisfactorily describes the data. The insights of this thesis are relevant for quantifying the contribution of mineral dust to the radiative energy balance of the Earth.
Download or read book Light Scattering Reviews Volume 11 written by Alexander Kokhanovsky and published by Springer. This book was released on 2016-05-12 with total page 522 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the eleventh volume in the series Light Scattering Reviews, devoted to current knowledge of light scattering problems and both experimental and theoretical research techniques related to their solution. The focus of this volume is to describe modern advances in radiative transfer and light scattering optics. This book brings together the most recent studies on light radiative transfer in the terrestrial atmosphere, while also reviewing environmental polarimetry. The book is divided into nine chapters: • the first four chapters review recent advances in modern radiative transfer theory and provide detailed descriptions of radiative transfer codes (e.g., DISORT and CRTM). Approximate solutions of integro-differential radiative transfer equations for turbid media with different shapes (spheres, cylinders, planeparallel layers) are detailed; • chapters 5 to 8 focus on studies of light scattering by single particles and radially inhomogeneous media; • the final chapter discusses the environmental polarimetry of man-made objects.
- Author : Prakash Gautam
- Publisher :
- Release : 2022
- ISBN :
- Pages : 0 pages
Light Scattering Study of Irregular Particles with Arbitrary Size Shape and Complex Refractive Index
Download or read book Light Scattering Study of Irregular Particles with Arbitrary Size Shape and Complex Refractive Index written by Prakash Gautam and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: We investigated light scattering due to irregularly shaped aerosol particles with diverse shapes, sizes, and complex refractive indices. We have designed and developed a light scattering setup based on a novel optical scheme that can detect light from 0.32° and 177.6°, from an extreme forward to the backscattering regime, involving 46 angles. Our setup was able to measure all six independent scattering matrix elements; however, we focused on measuring the scattering intensity and the linear depolarization ratio for different dust particles. Given the extremely small and large angles, the data obtained for our setup are plotted on both: versus scattering angle, [theta] linearly, and scattering wave vector, q or qR with R the radius of a particle, on a log-log scale, called [theta] and Q-space respectively. The Q- space analysis best represents the data at the extreme forward scattering regime; however, it compresses the data at the large scattering angles, [theta] , where useful data also reside. At large scattering angles, the scattered intensity is best viewed by [theta]-space analysis. We scattered the light from different aerosol particles viz; silicon dioxide (SiO2), aluminum abrasive (Al2O3), a highly refractive molybdenum disulfide (MoS2), a highly absorptive hematite particle ([alpha]--Fe2O3), arizona road dust and Soot particles. The measured scattered intensity was interpreted by applying both analysis methods. Light scattering for all particle types was compared to theoretical Mie scattering calculations using size distributions determined by an Aerodynamic Particle Sizer (APS 3321), an aerosol measuring instrument. The compared results between the experimentally measured data and Mie calculations showed a close agreement at the forward scattering regime and poorly at the side and backscattering regimes. Effects of the intensity-weighted size distribution were discussed. We applied Guinier analysis on light scattering measured data to compare light scattering inferred size to the intensity-weighted mean sizes for all shape particles. The light scattering sizes were consistent with the intensity-weighted mean sizes of reasonable accuracy for any shape and refractive index. This result has demonstrated the importance of intensity weighting of the size distribution in light scattering. We measured and studied the linear depolarization ratio for different dust particles. They all displayed a common pattern. The measured values were negligibly small at the forward scattering regime. They increased with increasing the scattering angle and reached a maximum at the side scattering regime that generally droped off at the backscattering regime. The effects of particle asphericity, size, and refractive index on the linear depolarization ratio were investigated. We further investigate the light scattering from fractal soot and non-fractal hematite aggregates. The results showed an enhancement in the backscattering despite a large imaginary refractive index. We found that enhancement backscattering for the non-fractal aggregate is due to internal multiple scattering between the grains within the aggregate. In contrast, enhancement backscattering is yet to be understood for fractal soot aggregates. Furthermore, the results presented in this work showed the sensitive of light backscattering with the change in particles' shapes, sizes, and refractive indices and warn the experimentalist to use the backscattering measured data with great caution.
Download or read book Light Scattering Reviews 3 written by Alexander A. Kokhanovsky and published by Springer Science & Business Media. This book was released on 2008-08-22 with total page 408 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the 3rd volume of a "Light Scattering Reviews" series devoted to current knowledge of light scattering problems and both experimental and theoretical research techniques related to their solution. This volume covers applications in remote sensing, inverse problems and geophysics, with a particular focus on terrestrial clouds. The influence of clouds on climate is poorly understood. The theoretical aspects of this problem constitute the main emphasis of this work.
Download or read book Investigation of Light Scattering as a Technique for Detecting Discrete Soot Particles in a Luminous Flame written by and published by . This book was released on 1978 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Light Scattering Reviews 5 written by Alexander A. Kokhanovsky and published by Springer Science & Business Media. This book was released on 2010-08-05 with total page 549 pages. Available in PDF, EPUB and Kindle. Book excerpt: Light scattering by densely packed inhomogeneous media is a particularly ch- lenging optics problem. In most cases, only approximate methods are used for the calculations. However, in the case where only a small number of macroscopic sc- tering particles are in contact (clusters or aggregates) it is possible to obtain exact results solving Maxwell’s equations. Simulations are possible, however, only for a relativelysmallnumberofparticles,especiallyiftheirsizesarelargerthanthewa- length of incident light. The ?rst review chapter in PartI of this volume, prepared by Yasuhiko Okada, presents modern numerical techniques used for the simulation of optical characteristics of densely packed groups of spherical particles. In this case, Mie theory cannot provide accurate results because particles are located in the near ?eld of each other and strongly interact. As a matter of fact, Maxwell’s equations must be solved not for each particle separately but for the ensemble as a whole in this case. The author describes techniques for the generation of shapes of aggregates. The orientation averaging is performed by a numerical integration with respect to Euler angles. The numerical aspects of various techniques such as the T-matrix method, discrete dipole approximation, the ?nite di?erence time domain method, e?ective medium theory, and generalized multi-particle Mie so- tion are presented. Recent advances in numerical techniques such as the grouping and adding method and also numerical orientation averaging using a Monte Carlo method are discussed in great depth.
Download or read book Springer Series in Light Scattering written by Alexander Kokhanovsky and published by Springer. This book was released on 2017-12-22 with total page 301 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents a survey of modern theoretical and experimental techniques in studies of light scattering phenomena and radiative transfer processes in random media. It presents reviews on light scattering by sea water and bubbles, and includes a separate chapter addressing studies of the remote sensing of crystalline clouds with a focus on the shape of particles—a parameter rarely studied by passive remote sensing techniques. In particular, it offers a comprehensive analysis of polarized radiative transfer in optically active (e.g., chiral) light scattering media and explores advances in spectro-polarimetry of particulate media. Lastly it discusses new developments in light scattering for combustion monitoring.
Download or read book Light Scattering in the Atmosphere written by and published by . This book was released on 1969 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt:
- Author : Bingqiang Sun
- Publisher : Elsevier
- Release : 2019-10-18
- ISBN : 0128180919
- Pages : 272 pages
Invariant Imbedding T matrix Method for Light Scattering by Nonspherical and Inhomogeneous Particles
Download or read book Invariant Imbedding T matrix Method for Light Scattering by Nonspherical and Inhomogeneous Particles written by Bingqiang Sun and published by Elsevier. This book was released on 2019-10-18 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt: Invariant Imbedding T-matrix Method for Light Scattering by Nonspherical and Inhomogeneous Particles propels atmospheric research forward as a resource and a tool for understanding the T-Matrix method in relation to light scattering. The text explores concepts ranging from electromagnetic waves and scattering dyads to the fundamentals of the T-Matrix method. Providing recently developed material, this text is sufficient to aid the light scattering science community with current and leading information. Enriched with detailed research from top field experts, Invariant Imbedding T-matrix Method for Light Scattering by Nonspherical and Inhomogeneous Particles offers a meaningful and essential presentation of methods and applications, with a focus on the light scattering of small and intermediate particles that supports and builds upon the latest studies. Thus, it is a valuable resource for atmospheric researchers and other earth and environmental scientists to expand their knowledge and understanding of available tools. Systematically introduces innovative methods with powerful numerical capabilities Thoroughly presents the rudimentary principles of light scattering and the T-matrix method Offers a condensed and well-ordered arrangement of text, figures and formulas that are serviceable for both students and researchers
Download or read book Light Scattering Reviews 4 written by Alexander A. Kokhanovsky and published by Springer Science & Business Media. This book was released on 2009-07-25 with total page 516 pages. Available in PDF, EPUB and Kindle. Book excerpt: This fourth volume of Light Scattering Reviews is composed of three parts. The ?rstpartisconcernedwiththeoreticalandexperimentalstudiesofsinglelightsc- tering by small nonspherical particles. Light scattering by small particles such as, for instance, droplets in the terrestrial clouds is a well understood area of physical optics. On the other hand, exact theoretical calculations of light scattering p- terns for most of nonspherical and irregularly shaped particles can be performed only for the restricted values of the size parameter, which is proportional to the ratio of the characteristic size of the particle to the wavelength?. For the large nonspherical particles, approximations are used (e. g. , ray optics). The exact th- retical techniques such as the T-matrix method cannot be used for extremely large particles, such as those in ice clouds, because then the size parameter in the v- iblex=2?a/???,wherea is the characteristic size (radius for spheres), and the associated numerical codes become unstable and produce wrong answers. Yet another problem is due to the fact that particles in many turbid media (e. g. , dust clouds) cannot be characterized by a single shape. Often, refractive indices also vary. Because of problems with theoretical calculations, experimental (i. e. , la- ratory) investigations are important for the characterization and understanding of the optical properties of such types of particles. The ?rst paper in this volume, written by B. Gustafson, is aimed at the descr- tionofscaledanalogueexperimentsinelectromagneticscattering.
Download or read book Light Scattering Media Optics written by Alex A. Kokhanovsky and published by Springer Science & Business Media. This book was released on 2004-08-05 with total page 332 pages. Available in PDF, EPUB and Kindle. Book excerpt: The theory of the scattering of light by small particles is very important in a wide range of applications in atmospheric physics and atmospheric optics, ocean optics, remote sensing, astronomy and astrophysics and biological optics. This book summarises current knowledge of the optical properties of single small particles and natural light scattering media such as snow, clouds, foam aerosols etc. The book considers both single and multiple light scattering regimes, together with light scattering and radiative transfer in close-packed media. The third edition incorporates new findings in the area of light scattering media optics in an updated version of the text.
Download or read book Electromagnetic Scattering by Particles and Particle Groups written by Michael I. Mishchenko and published by Cambridge University Press. This book was released on 2014-04-24 with total page 470 pages. Available in PDF, EPUB and Kindle. Book excerpt: This self-contained and accessible book provides a thorough introduction to the basic physical and mathematical principles required in studying the scattering and absorption of light and other electromagnetic radiation by particles and particle groups. For the first time the theories of electromagnetic scattering, radiative transfer, and weak localization are combined into a unified, consistent branch of physical optics directly based on the Maxwell equations. A particular focus is given to key aspects such as time and ensemble averaging at different scales, ergodicity, and the physical nature of measurements afforded by actual photopolarimeters. Featuring over 120 end-of-chapter exercises, with hints and solutions provided, this clear, one-stop resource is ideal for self-study or classroom use, and will be invaluable to both graduate students and researchers in remote sensing, physical and biomedical optics, optical communications, optical particle characterization, atmospheric physics and astrophysics.