Aerosol Optics


Book Description

This new text offers experienced students a comprehensive review of available techniques for the remote sensing of aerosols. These small particles influence both atmospheric visibility and the thermodynamics of the atmosphere. They are also of great importance in any consideration of climate change problems. Aerosols may also be responsible for the loss of harvests, human health problems and ecological disasters. Thus, this detailed study of aerosol properties on a global scale could not be more timely.







Models for the Aerosols of the Lower Atmosphere and the Effects of Humidity Variations on Their Optical Properties


Book Description

Aerosol models have been developed for the lower atmosphere. These models are representative of conditions found in rural, urban, and maritime air masses. The changes in the aerosol properties with variations in the relative humidity are discussed. To describe the aerosol optical properties in the extreme of 100 percent relative humidity, several fog models are presented. For each model the coefficients for extinction, scattering, and absorption, the angular scattering distribution, and other optical parameters have been computed for wavelengths between 0.2 and 40 microns. These aerosol models are presented together with a review of their experimental basis. The optical properties of these models are discussed and some comparisons of the model with experimental measurements are presented.




Ground-Based Aerosol Optical Depth Measurement Using Sunphotometers


Book Description

This book gives a detailed review on ground-based aerosol optical depth measurement with emphasis on the calibration issue. The review is written in chronological sequence to render better comprehension on the evolution of the classical Langley calibration from the past to present. It not only compiles the existing calibration methods but also presents a novel calibration algorithm in Langley sun-photometry over low altitude sites which conventionally is a common practice performed at high observatory stations. The proposed algorithm avoids travelling to high altitudes for frequent calibration that is difficult both in logistics and financial prospects. We addressed the problem by combining clear-sky detection model and statistical filter to strictly imitate the ideal clear-sky condition at high altitude for measurements taken over low altitudes. In this way, the possible temporal atmospheric drifts, abundant aerosol loadings and short time interval cloud transits are properly constrained. We believe that this finding has an integral part of practicality and versatility in ground-based aerosol optical depth measurement, which is nowadays an important climate agent in many atmospheric studies. Finally, the outcome of this book introduces a new calibration technique for the study and measurement of aerosol monitoring with emphasis on aerosol optical depth that we believe could be very beneficial to researchers and scientists in the similar area.




Atmospheric Aerosol Properties


Book Description

This book provides the first comprehensive analysis of how aerosols form in the atmosphere through in situ processes as well as via transport from the surface (dust storms, seas spray, biogenic emissions, forest fires etc.). Such an analysis has been followed by the consideration of both observation data (various field observational experiments) and numerical modeling results to assess climate impacts of aerosols bearing in mind that these impacts are the most significant uncertainty in studying natural and anthropogenic causes of climate change.




Atmospheric Optics Measurements with a Balloon-borne Nephelometer


Book Description

A large modified polar nephelometer was constructed for the purpose of making high altitude atmospheric optics measurements. The instrument is balloon-borne and measures the angular volume scattering function from ground to better than 26 km in absolute quantities. The results of the initial flight with the unit are presented and they depict the variability in this parameter over the altitude profile for three scattering angles and four wavelengths. In addition, the polarization and the forward-to-backscatter ratio of the scattered light are shown to be sensitive indicators of the atmosphere's vertical aerosol structure. The import of these preliminary results is, however, in pointing out the capabilities of this instrument, which can provide quantitative information on fundamental optical parameters of the atmosphere without the constraints inherent in other techniques.




Aerosols


Book Description







Light Scattering Media Optics


Book Description

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.




Recent Advances in Aerosol Research


Book Description

Recent Advances in Aerosol Research: A Bibliographical Review presents a bibliographic review of advances in aerosol research covering the period from the beginning of 1957 to the end of 1962. Topics covered include chemical reactions, combustion, coagulation and diffusion, and adhesion of particles. References on filtration, evaporation and condensation, nucleation and growth, and laminar flow and impingement are also included. This volume is comprised of 19 chapters and begins by citing research on acoustic, ultrasonic, and shock wave effects, along with adhesion of particles, chemical reactions, combustion, coagulation and diffusion, and filtration. The following chapters deal with evaporation and condensation, nucleation and growth, laminar flow and impingement, generators, photophoresis, and the optics of aerosols. Other chapters focus on radioactivity, sampling instruments, sedimentation and fluid resistance, thermophoresis, and diffusiophoresis. The last chapter highlights turbulent flow and deposition of aerosols. This monograph will be a valuable resource for researchers and practitioners interested in aerosols.