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 Springer Series in Light Scattering written by Alexander Kokhanovsky and published by Springer. This book was released on 2018-01-17 with total page 369 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents recent advances in studies of light propagation, scattering, emission and absorption in random media. Many natural and biological media vary randomly in time and space. Examples are terrestrial atmosphere and ocean, biological liquids and tissues to name but a few.
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 Light Scattering Reviews 9 written by Alexander A. Kokhanovsky and published by Springer. This book was released on 2014-09-22 with total page 437 pages. Available in PDF, EPUB and Kindle. Book excerpt: Light Scattering Reviews (vol. 9) is aimed at the description of modern advances in radiative transfer and light scattering. The following topics will be considered: light scattering by atmospheric dust particles and also by inhomogeneous scatterers, the general - purpose discrete - ordinate algorithm DISORT for radiative transfer, the radiative transfer code RAY based on the adding-doubling solution of the radiative transfer equation, aerosol and cloud remote sensing, use of polarization in remote sensing, direct aerosol radiative forcing, principles of the Mueller matrix measurements, light reflectance from various land surfaces. This volume will be a valuable addition to already published volumes 1-8 of Light Scattering Reviews.
Download or read book Light Scattering by Ice Crystals and Mineral Dust Aerosols in the Atmosphere written by Lei Bi and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Modeling the single-scattering properties of nonspherical particles in the atmosphere (in particular, ice crystals and dust aerosols) has important applications to climate and remote sensing studies. The first part of the dissertation (Chapters II-V) reports a combination of exact numerical methods, including the finite-difference time-domain (FDTD), the discrete-dipole-approximation (DDA), and the T-matrix methods, and an approximate method-the physical-geometric optics hybrid (PGOH) method-in the computation of the optical properties of the non-spherical particles in a complete range of size parameters. The major advancements are made on the modeling capabilities of the PGOH method, and the knowledge of the electromagnetic tunneling effect -- a semi-classical scattering effect. This research is important to obtain reliable optical properties of nonspherical particles in a complete range of size parameters with satisfactory accuracy and computational efficiency. The second part (Chapters VI-VII) of the dissertation is to investigate the dependence of the optical properties of ice crystals and mineral dust aerosols in the atmosphere on the spectrum, the particle size and the morphology based on computational models. Ice crystals in the atmosphere can be classified to be simple regular faceted particles (such as hexagon columns, plates, etc.) and imperfect ice crystals. Modeling of the scattering by regular ice crystals is straightforward, as their morphologies can be easily defined. For imperfect ice crystals, the morphology is quite diverse, which complicates the modeling process. We present an effective approach of using irregular faceted particle to characterize the imperfectness of ice crystals. As an example of application, less-than-unity backscattering color ratio of cirrus clouds is demonstrated and explained theoretically, which provides guidance in the calibration algorithm for 1.064-[mu]m channel on the Calipso lidar. Dust aerosols have no particular morphology. To develop an approach to modeling the optical properties of realistic dust particles, the principle of using simple shapes (triaxial ellipsoids and nonsymmetric hexahedra) to represent irregular dust particles is explored. Simulated results have been compared with those measured in laboratory for several realistic aerosol samples. Agreement between simulated results and measurement suggests the potential applicability of the two aforementioned aerosol models. We also show the potential impact of the present study to passive and active atmospheric remote sensing and future research works.
Download or read book Light Scattering Reviews 8 written by Alexander A. Kokhanovsky and published by Springer Science & Business Media. This book was released on 2013-06-12 with total page 653 pages. Available in PDF, EPUB and Kindle. Book excerpt: Light scattering review (vol 8) is aimed at the presentation of recent advances in radiative transfer and light scattering optics. The topics to be covered include: scattering of light by irregularly shaped particles suspended in atmosphere (dust, ice crystals), light scattering by particles much larger as compared the wavelength of incident radiation, atmospheric radiative forcing, astrophysical radiative transfer, radiative transfer and optical imaging in biological media, radiative transfer of polarized light, numerical aspects of radiative transfer.
Download or read book Scattering Absorption and Emission of Light by Small Particles written by Michael I. Mishchenko and published by Cambridge University Press. This book was released on 2002-06-06 with total page 562 pages. Available in PDF, EPUB and Kindle. Book excerpt: A thorough and up-to-date treatment of electromagnetic scattering by small particles.
Download or read book Light Scattering by Small Particles written by H. C. van de Hulst and published by Courier Corporation. This book was released on 2012-06-08 with total page 502 pages. Available in PDF, EPUB and Kindle. Book excerpt: Comprehensive treatment of light-scattering properties of small, independent particles, including a full range of useful approximation methods for researchers in chemistry, meteorology, and astronomy. 46 tables. 59 graphs. 44 illustrations.
Download or read book An Investigation Into Particle Shape Effects on the Light Scattering Properties of Mineral Dust Aerosol written by Brian Steven Meland and published by . This book was released on 2011 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt: It was found that the theoretical model simulations differed markedly from experimental measurements of the light scattering, particularly near the mid-range and near backscattering angles. In many cases, in the near backward direction, theoretical models predicted scattering intensities for near spherical particles that were up to 3 times higher than the experimentally measured values. It was found that better agreement between simulations and experiments could be obtained for the visible scattering by using a much wider range of more eccentric particle shapes.
Download or read book Light Scattering by Nonspherical Particles written by Michael I. Mishchenko and published by Elsevier. This book was released on 1999-09-22 with total page 721 pages. Available in PDF, EPUB and Kindle. Book excerpt: There is hardly a field of science or engineering that does not have some interest in light scattering by small particles. For example, this subject is important to climatology because the energy budget for the Earth's atmosphere is strongly affected by scattering of solar radiation by cloud and aerosol particles, and the whole discipline of remote sensing relies largely on analyzing the parameters of radiation scattered by aerosols, clouds, and precipitation. The scattering of light by spherical particles can be easily computed using the conventional Mie theory. However, most small solid particles encountered in natural and laboratory conditions have nonspherical shapes. Examples are soot and mineral aerosols, cirrus cloud particles, snow and frost crystals, ocean hydrosols, interplanetary and cometary dust grains, and microorganisms. It is now well known that scattering properties of nonspherical particles can differ dramatically from those of "equivalent" (e.g., equal-volume or equal-surface-area) spheres. Therefore, the ability to accurately compute or measure light scattering by nonspherical particles in order to clearly understand the effects of particle nonsphericity on light scattering is very important. The rapid improvement of computers and experimental techniques over the past 20 years and the development of efficient numerical approaches have resulted in major advances in this field which have not been systematically summarized. Because of the universal importance of electromagnetic scattering by nonspherical particles, papers on different aspects of this subject are scattered over dozens of diverse research and engineering journals. Often experts in one discipline (e.g., biology) are unaware of potentially useful results obtained in another discipline (e.g., antennas and propagation). This leads to an inefficient use of the accumulated knowledge and unnecessary redundancy in research activities. This book offers the first systematic and unified discussion of light scattering by nonspherical particles and its practical applications and represents the state-of-the-art of this important research field. Individual chapters are written by leading experts in respective areas and cover three major disciplines: theoretical and numerical techniques, laboratory measurements, and practical applications. An overview chapter provides a concise general introduction to the subject of nonspherical scattering and should be especially useful to beginners and those interested in fast practical applications. The audience for this book will include graduate students, scientists, and engineers working on specific aspects of electromagnetic scattering by small particles and its applications in remote sensing, geophysics, astrophysics, biomedical optics, and optical engineering. - The first systematic and comprehensive treatment of electromagnetic scattering by nonspherical particles and its applications - Individual chapters are written by leading experts in respective areas - Includes a survey of all the relevant literature scattered over dozens of basic and applied research journals - Consistent use of unified definitions and notation makes the book a coherent volume - An overview chapter provides a concise general introduction to the subject of light scattering by nonspherical particles - Theoretical chapters describe specific easy-to-use computer codes publicly available on the World Wide Web - Extensively illustrated with over 200 figures, 4 in color
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 Light Scattering by Nonspherical Particles written by Michael I Mishchenko and published by Academic Press. This book was released on 1999-09-27 with total page 690 pages. Available in PDF, EPUB and Kindle. Book excerpt: There is hardly a field of science or engineering that does not have some interest in light scattering by small particles. For example, this subject is important to climatology because the energy budget for the Earth's atmosphere is strongly affected by scattering of solar radiation by cloud and aerosol particles, and the whole discipline of remote sensing relies largely on analyzing the parameters of radiation scattered by aerosols, clouds, and precipitation. The scattering of light by spherical particles can be easily computed using the conventional Mie theory. However, most small solid particles encountered in natural and laboratory conditions have nonspherical shapes. Examples are soot and mineral aerosols, cirrus cloud particles, snow and frost crystals, ocean hydrosols, interplanetary and cometary dust grains, and microorganisms. It is now well known that scattering properties of nonspherical particles can differ dramatically from those of "equivalent" (e.g., equal-volume or equal-surface-area) spheres. Therefore, the ability to accurately compute or measure light scattering by nonspherical particles in order to clearly understand the effects of particle nonsphericity on light scattering is very important. The rapid improvement of computers and experimental techniques over the past 20 years and the development of efficient numerical approaches have resulted in major advances in this field which have not been systematically summarized. Because of the universal importance of electromagnetic scattering by nonspherical particles, papers on different aspects of this subject are scattered over dozens of diverse research and engineering journals. Often experts in one discipline (e.g., biology) are unaware of potentially useful results obtained in another discipline (e.g., antennas and propagation). This leads to an inefficient use of the accumulated knowledge and unnecessary redundancy in research activities. This book offers the first systematic and unified discussion of light scattering by nonspherical particles and its practical applications and represents the state-of-the-art of this important research field. Individual chapters are written by leading experts in respective areas and cover three major disciplines: theoretical and numerical techniques, laboratory measurements, and practical applications. An overview chapter provides a concise general introduction to the subject of nonspherical scattering and should be especially useful to beginners and those interested in fast practical applications. The audience for this book will include graduate students, scientists, and engineers working on specific aspects of electromagnetic scattering by small particles and its applications in remote sensing, geophysics, astrophysics, biomedical optics, and optical engineering. * The first systematic and comprehensive treatment of electromagnetic scattering by nonspherical particles and its applications * Individual chapters are written by leading experts in respective areas * Includes a survey of all the relevant literature scattered over dozens of basic and applied research journals * Consistent use of unified definitions and notation makes the book a coherent volume * An overview chapter provides a concise general introduction to the subject of light scattering by nonspherical particles * Theoretical chapters describe specific easy-to-use computer codes publicly available on the World Wide Web * Extensively illustrated with over 200 figures, 4 in color
Download or read book Light Scattering by Particles written by Peter W. Barber and published by World Scientific. This book was released on 1990 with total page 280 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents the separation-of-variables and T-matrix methods of calculating the scattering of electromagnetic waves by particles. Analytical details and computer programs are provided for determining the scattering and absorption characteristics of the finite-thickness slab, infinite circular cylinder (normal incidence), general axisymmetric particle, and sphere.The computer programs are designed to generate data that is easy to graph and visualize, and test cases in the book illustrate the capabilities of the programs. The connection between the theory and the computer programs is reinforced by references in the computer programs to equations in the text. This cross-referencing will help the reader understand the computer programs, and, if necessary, modify them for other purposes.
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 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 2022-09-13 with total page 201 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is aimed at description of recent progress in studies of multiple and single light scattering in turbid media. Light scattering and radiative transfer research community will greatly benefit from the publication of this book.
Download or read book Absorption and Scattering of Light by Small Particles written by Craig F. Bohren and published by Wiley-VCH. This book was released on 1983-04-15 with total page 554 pages. Available in PDF, EPUB and Kindle. Book excerpt: Treating absorption and scattering in equal measure, this self-contained, interdisciplinary study examines and illustrates how small particles absorb and scatter light. The authors emphasize that any discussion of the optical behavior of small particles is inseparable from a full understanding of the optical behavior of the parent material-bulk matter. To divorce one concept from the other is to render any study on scattering theory seriously incomplete.
