Download or read book Modeling of the Optical Properties of Nonspherical Particles in the Atmosphere written by Guang Chen and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The single scattering properties of atmospheric particles are fundamental to radiative simulations and remote sensing applications. In this study, an efficient technique, namely, the pseudo-spectral time-domain (PSTD) method which was first developed to study acoustic wave propagation, is applied to the scattering of light by nonspherical particles with small and moderate size. Five different methods are used to discretize Maxwell's equations in the time domain. The perfectly matched layer (PML) absorbing boundary condition is employed in the present simulation for eliminating spurious wave propagations caused by the spectral method. A 3-D PSTD code has been developed on the basis of the five aforementioned discretization methods. These methods provide essentially the same solutions in both absorptive and nonabsorptive cases. In this study, the applicability of the PSTD method is investigated in comparison with the Mie theory and the T-matrix method. The effects of size parameter and refractive index on simulation accuracy are discussed. It is shown that the PSTD method is quite accurate when it is applied to the scattering of light by spherical and nonspherical particles, if the spatial resolution is properly selected. Accurate solutions can also be obtained from the PSTD method for size parameter of 80 or refractive index of 2.0+j0. Six ice crystal habits are defined for the PSTD computational code. The PSTD results are compared with the results acquired from the finite difference time domain (FDTD) method at size parameter 20. The PSTD method is about 8-10 times more efficient than the conventional FDTD method with similar accuracy. In this study, the PSTD is also applied to the computation of the phase functions of ice crystals with a size parameter of 50. Furthermore, the PSTD, the FDTD, and T-matrix methods are applied to the study of the optical properties of horizontally oriented ice crystals. Three numerical schemes for averaging horizontal orientations are developed in this study. The feasibility of using equivalent circular cylinders as surrogates of hexagonal prisms is discussed. The horizontally oriented hexagonal plates and the equivalent circular cylinders have similar optical properties when the size parameter is in the region about from 10 to 40. Otherwise, the results of the two geometries are substantially different.
Download or read book Optical Properties of the Atmosphere Revised written by R. A. McClatchey and published by . This book was released on 1971 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt: A series of tables and charts is presented from which the atmospheric transmittance between any two points in the terrestrial atmosphere can be determined. This material is based on a set of five atmospheric models ranging from tropical to arctic and two aerosol models. A selected set of laser frequencies has been defined for which monochromatic transmittance values have been given. For low resolution transmittance prediction, a series of charts has been drawn providing the capability for predicting transmittance at a resolution of 20 wavenumbers. Separate sections are included on scattered solar radiation, infrared emission, refractive effects, and attenuation by cloud and fog.
Download or read book Optical Properties of the Atmosphere written by R. A. McClatchey and published by . This book was released on 1970 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Optical Properties of the Atmosphere Third Edition written by R. A. McClatchey and published by . This book was released on 1972 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt: A series of tables and charts is presented from which the atmospheric transmittance between any two points in the terrestrial atmosphere can be determined. This material is based on a set of five atmospheric models ranging from tropical to arctic and two aerosol models. A selected set of laser frequencies has been defined for which monochromatic transmittance values have been given. For low resolution transmittance predcition, a series of charts has been drawn providing the capability for predicting transmittance at a resolution of 20 wave-numbers. Separate sections are included on scattered solar radiation, infrared emission, refractive effects, and attenuation by cloud and fog. This third edition differs from the others in that the low resolution spectral curves for the uniformly mixed gases and in the short wavelength region for water vapor have been revised, providing some overall improvement in accuracy; and more importantly, an appendix has been added providing model data and equivalent sea level path data for the U.S. Standard Atmosphere, 1962.
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 Scattering from Model Nonspherical Particles written by Ferdinando Borghese and published by Springer Science & Business Media. This book was released on 2013-03-09 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides the first coherent account of a well-known approach to the problem of light scattering by small anisotropic particles. In this extended second edition the authors have encompassed all the new topics arising from their recent studies of cosmic dust grains. Thus many chapters were deeply revised and new chapters were added. The book addresses a wide spectrum of applications.
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 Simulation of the Optical Properties of Atmospheric Aerosols in the Planetary Boundary Layer BPL written by and published by . This book was released on 2002 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: We report in this paper the relevant results obtained for the calculation and the retrieving of the optical properties of the particles that can constitute the atmospheric aerosols. In the first section we present the preliminary results of computations of the optical properties (extinction and backscattering) for low density dispersions of particles with an irregular shape. These particles are modelled as clusters of spheres and the calculated Lidar ratios will be compared with the other computations performed using spheres with Mie theory. The values of the lidar ratio will also constitute the data base for the interpretation of the experimental data obtained with LIDAR systems. In the second section we implemented a neural network that proved to be a useful tool for the recognition of the microphysical properties of a low density dispersion of spherical particles from the angular pattern. In future we plan to extend the algorithm to the recognition of the optical parameters for nonspherical particles. In the third section we have explored the scattering properties of the irregular shaped aerosols by means an angular analysis in the IR-VIS range aimed to compare the calculated scattering patterns with the experimental ones obtained with a two-dimensional angular optical scattering device (TAOS). More extended comments are contained in a paper that will be published in Applied Optics.
Download or read book Optical Properties of the Atmosphere written by R. A. McClatchey and published by . This book was released on 1972 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt: A series of tables and charts is presented from which the atmospheric transmittance between any two points in the terrestrial atmosphere can be determined. This material is based on a set of five atmospheric models ranging from tropical to arctic and two aerosol models. A selected set of laser frequencies has been defined for which monochromatic transmittance values have been given. For low resolution transmittance predcition, a series of charts has been drawn providing the capability for predicting transmittance at a resolution of 20 wave-numbers. Separate sections are included on scattered solar radiation, infrared emission, refractive effects, and attenuation by cloud and fog. This third edition differs from the others in that the low resolution spectral curves for the uniformly mixed gases and in the short wavelength region for water vapor have been revised, providing some overall improvement in accuracy; and more importantly, an appendix has been added providing model data and equivalent sea level path data for the U.S. Standard Atmosphere, 1962.
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 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 Ice Crystals written by Kuo-Nan Liou and published by Cambridge University Press. This book was released on 2016-10-06 with total page 461 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume outlines the fundamentals and applications of light scattering, absorption and polarization processes involving ice crystals.
Download or read book Remote Sensing of the Earth from Space Atmospheric Correction written by Kirill Y. Kondratyev and published by Springer Science & Business Media. This book was released on 2013-11-11 with total page 484 pages. Available in PDF, EPUB and Kindle. Book excerpt: The monograph being proposed for the English-speaking research community is concentrated on the atmospheric correction of satellite images as a part of thematic interpretation procedures while processing remote sensing data. For linguistic reasons a large section of the community may have been unaware of the progress made in Russia in this field of science and technology. Meanwhile, Russia was the first country to launch the first artificial satellite in 1957 and to obtain from space for the first time spectra of the Earth's atmosphere in the 1960's. New applications of the radiation transfer theory for the atmosphere underlying surface system appeared first in Russia in the 1970's. Direct and in verse problems of the atmospheric optics were then formulated giving the scientific basis for studies of natural resources from space. Since that time new mathematical treatments for the atmospheric correction procedures have been widely developed in Russia, including both analytical and numerical tech niques to simulate spectral, angular, and spatial distributions of the outgoing radiation in visual and infrared regions. The authors of the book were at the beginning of the scientific approach. A wide range of mathematical im provements to elaborate polinomial approximations for dependencies between atmospheric radiation field and parameters of space surveying was due to the necessity to process satellite images in real time using special software of ex isted computer means for the studies.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1994 with total page 892 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Light Scattering by Particles in Water written by Miroslaw Jonasz and published by Elsevier. This book was released on 2011-08-29 with total page 715 pages. Available in PDF, EPUB and Kindle. Book excerpt: Light scattering-based methods are used to characterize small particles suspended in water in a wide range of disciplines ranging from oceanography, through medicine, to industry. The scope and accuracy of these methods steadily increases with the progress in light scattering research. This book focuses on the theoretical and experimental foundations of the study and modeling of light scattering by particles in water and critically evaluates the key constraints of light scattering models. It begins with a brief review of the relevant theoretical fundamentals of the interaction of light with condensed matter, followed by an extended discussion of the basic optical properties of pure water and seawater and the physical principles that explain them. The book continues with a discussion of key optical features of the pure water/seawater and the most common components of natural waters. In order to clarify and put in focus some of the basic physical principles and most important features of the experimental data on light scattering by particles in water, the authors employ simple models. The book concludes with extensive critical reviews of the experimental constraints of light scattering models: results of measurements of light scattering and of the key properties of the particles: size distribution, refractive index (composition), structure, and shape. These reviews guide the reader through literature scattered among more than 210 scientific journals and periodicals which represent a wide range of disciplines. A special emphasis is put on the methods of measuring both light scattering and the relevant properties of the particles, because principles of these methods may affect interpretation and applicability of the results. The book includes extensive guides to literature on light scattering data and instrumentation design, as well as on the data for size distributions, refractive indices, and shapes typical of particles in natural waters. It also features a comprehensive index, numerous cross-references, and a reference list with over 1370 entries. An errata sheet for this work can be found at: http://www.tpdsci.com/Ref/Jonasz_M_2007_LightScatE.php *Extensive reference section provides handy compilations of knowledge on the designs of light scattering meters, sources of experimental data, and more *Worked exercises and examples throughout
Download or read book Handbook of Molecular Plasmonics written by Fabio Della Sala and published by CRC Press. This book was released on 2013-08-13 with total page 483 pages. Available in PDF, EPUB and Kindle. Book excerpt: While several reviews and books on surface nanophotonics and fluorescence spectroscopy are available, an updated focus on molecular plasmonics, including both theoretical methods and experimental aspects, is still lacking. This handbook is a comprehensive overview on the physics of the plasmon-emitter interaction, ranging from electromagnetism to q
Download or read book Handbook of Geophysics and Space Environments written by U.S. Air Force Geophysics Laboratory and published by . This book was released on 1985 with total page 1066 pages. Available in PDF, EPUB and Kindle. Book excerpt:
