Download or read book Studying Clouds and Aerosols with Lidar Depolarization Ratio and Backscatter Relationships written by Hyoun-Myoung Cho and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation consists of three parts, each devoted to a particular issue of significant importance for CALIPSO lidar observation of depolarization ratio (delta) and backscatter (gamma?) to improve current understanding of the microphysical properties of clouds and aerosols. The relationships between depolarization ratio and backscatter allow us to retrieve particle thermodynamic phase and shape and/or orientation of aerosols and clouds. The first part is devoted to the investigation of the relationships between lidar backscatter and the corresponding depolarization ratio for different cloud classifications and aerosol types. For each cloud and aerosol types, layer-averaged backscatter and backscattering depolarization ratio from the CALIPSO measurements are discussed. The present results demonstrate the unique capabilities of the CALIPSO lidar instrument for determining cloud phase and aerosols subtypes. In the second part, we evaluate the MODIS IR cloud phase with the CALIPSO cloud products. The three possible misclassifications of MODIS IR cloud phasealgorithm, which are studied by Nasiri and Kahn (2008) with radiative transfer modeling, are tested by comparing between MODIS IR phase and CALIOP observations. The current results support their hypotheses, which is that the MODIS phase algorithm may tend to classify thin cirrus clouds as water clouds or mixed phase clouds or unknown, and classify midlevel and/or mid-temperature clouds as mixed or unknown phase. In the third part, we present a comparison of mineral dust aerosol retrievals from two instruments, MODIS and CALIPSO lidar. And, we implement and evaluate a new mineral dust detection algorithm based on the analysis of thin dust radiative signature. In comparison, three commonly used visible and IR mineral dust detection algorithms, including BTD procedure, D parameter method, and multi-channel image algorithm, are evaluated with CALIPSO aerosol classification. The comparison reveals that those dust detection algorithms are not effective for optically thin dust layers, but for thick dust storm. The new algorithm using discriminant analysis with CALIPSO observation is much better in detecting thin dust layer of optical thickness between 0.1 and 2.
Download or read book Remote Sensing of Aerosols Clouds and Precipitation written by Tanvir Islam and published by Elsevier. This book was released on 2017-10-18 with total page 366 pages. Available in PDF, EPUB and Kindle. Book excerpt: Remote Sensing of Aerosols, Clouds, and Precipitation compiles recent advances in aerosol, cloud, and precipitation remote sensing from new satellite observations. The book examines a wide range of measurements from microwave (both active and passive), visible, and infrared portions of the spectrum. Contributors are experts conducting state-of-the-art research in atmospheric remote sensing using space, airborne, and ground-based datasets, focusing on supporting earth observation satellite missions for aerosol, cloud, and precipitation studies. A handy reference for scientists working in remote sensing, earth science, electromagnetics, climate physics, and space engineering. Valuable for operational forecasters, meteorologists, geospatial experts, modelers, and policymakers alike. Presents new approaches in the field, along with further research opportunities, based on the latest satellite data Focuses on how remote sensing systems can be designed/developed to solve outstanding problems in earth and atmospheric sciences Edited by a dynamic team of editors with a mixture of highly skilled and qualified authors offering world-leading expertise in the field
Download or read book Backscatter Laser Depolarization Studies of Simulated Stratospheric Aerosols written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-08-16 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: The optical depolarizing properties of simulated stratospheric aerosols were studied in laboratory laser (0.633 micrometer) backscattering experiments for application to polarization lidar observations. Clouds composed of sulfuric acid solution droplets, some treated with ammonia gas, were observed during evaporation. The results indicate that the formation of minute ammonium sulfate particles from the evaporation of acid droplets produces linear depolarization ratios of beta equivalent to 0.02, but beta equivalent to 0.10 to 0.15 are generated from aged acid cloud aerosols and acid droplet crystallization effects following the introduction of ammonia gas into the chamber. It is concluded that partially crystallized sulfuric acid droplets are a likely candidate for explaining the lidar beta equivalent to 0.10 values that have been observed in the lower stratosphere in the absence of the relatively strong backscattering from homogeneous sulfuric acid droplet (beta equivalent to 0) or ice crystal (beta equivalent to 0.5) clouds. Sassen, Kenneth and Zhao, Hongjie and Yu, Bing-Kun Unspecified Center NASA-CR-183387, NAS 1.26:183387 NAG1-686...
Download or read book Improved Simulation of Aerosol Cloud and Density Measurements by Shuttle Lidar written by and published by . This book was released on 1981 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Lidar Remote Sensing for Industry and Environment Monitoring III written by Upendra N. Singh and published by SPIE-International Society for Optical Engineering. This book was released on 2003 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Improved Simulation of Aerosol Cloud and Density Measurements by Shuttle Lidar written by Philip B. Russell and published by . This book was released on 1981 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book High Resolution Active Optical Remote Sensing Observations of Aerosols Clouds and Aerosol Cloud Interactions and Their Implication to Climate written by Simone Lolli and published by MDPI. This book was released on 2020-12-03 with total page 242 pages. Available in PDF, EPUB and Kindle. Book excerpt: Remote Sensing is of paramount importance for Earth Observation to monitor and analyze the Earth’s vital signs. In this Special Issue are reported the latest research results involving active optical remote sensing instruments, both from ground-based to satellite platforms, that are involved in analyzing the vertical and horizontal aerosol and cloud distribution, other than their geometrical, optical and microphysical properties. Those active optical remote sensing techniques are also very useful in determining pollutant dispersion and the dynamics inside the boundary layer. The published studies put in evidence the hidden mechanisms on how pollution from the source is advected transnationally in other countries and the interaction with local meteorology.
Download or read book Lidar written by Claus Weitkamp and published by Springer Science & Business. This book was released on 2006-06-03 with total page 467 pages. Available in PDF, EPUB and Kindle. Book excerpt: Written by leading experts in optical radar, or lidar, this book brings all the recent practices up-to-date. With a Foreword by one of the founding fathers in the area. Its broad cross-disciplinary scope should appeal to scientists ranging from the view of optical sciences to environmental engineers. Optical remote sensing has matured to become a lead method for cross-disciplinary research. This new multi-authored book reviews the state-of-the-art in a readable monograph.
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 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 on Cirrus Clouds by the Cloud aerosol Lidar and Infrared Pathfinder Satellite Observation Data written by Jiang Zhu and published by . This book was released on 2011 with total page 406 pages. Available in PDF, EPUB and Kindle. Book excerpt: Understanding and describing the role of clouds in the climate system need intensive and extensive research on cloud properties. The albedo and greenhouse effects of clouds and their relations with the physical properties of clouds are analyzed. Cloud-top height and ice water content are key factors in impacting the longwave and shortwave radiation, respectively. Lidar and infrared radiometer measurement technologies are introduced. Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) level I Lidar profile, level 2 cloud layer, and level 2 Lidar/IIR track products are briefly reviewed. The algorithms for identification of cirrus clouds, Linear Depolarization Ratio (LDR), and effective diameter are presented. An average LDR profile is calculated by using the sum of total attenuated backscattering profiles and the sum of perpendicular attenuated backscattering profiles. A weight-average method is applied to calculate the average LDR. A split-window method is applied to estimate the effective diameters of clouds. A set of bulk ice crystal models and a radiative transfer model are applied to produce a look-up table that includes the radiative transfer simulation results. The macro-physical properties of cirrus clouds are analyzed. The frequency of occurrence of cirrus clouds varies with latitude, and strongly relates to the atmospheric circulation. Cirrus clouds are few in high-pressure zones and abundant where seasonal monsoonal circulation occurs. Cloud-top height decreases with increasing latitude. Cloud-top temperature is lower in the tropical regions than in the midlatutude and the polar regions. The measured cloud thickness shows a great diurnal variation. CALIPSO lidar detects more cirrus clouds than satellite-based passive measurement. LDR values of cirrus clouds vary with latitude and location, and are higher during nighttime than during daytime. The 0.32 and 0.37 annual average LDRs derived by nadir and off-nadir measurements, respectively, indicate that substantial amounts of horizontal orientated ice crystals exist in cirrus clouds. The global distribution of effective diameter of cirrus clouds varies with latitude and season, and the effective diameter has relationship with the LDR.
Download or read book Mixed Phase Clouds written by Constantin Andronache and published by Elsevier. This book was released on 2017-09-28 with total page 302 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mixed-Phase Clouds: Observations and Modeling presents advanced research topics on mixed-phase clouds. As the societal impacts of extreme weather and its forecasting grow, there is a continuous need to refine atmospheric observations, techniques and numerical models. Understanding the role of clouds in the atmosphere is increasingly vital for current applications, such as prediction and prevention of aircraft icing, weather modification, and the assessment of the effects of cloud phase partition in climate models. This book provides the essential information needed to address these problems with a focus on current observations, simulations and applications. Provides in-depth knowledge and simulation of mixed-phase clouds over many regions of Earth, explaining their role in weather and climate Features current research examples and case studies, including those on advanced research methods from authors with experience in both academia and the industry Discusses the latest advances in this subject area, providing the reader with access to best practices for remote sensing and numerical modeling
Download or read book A Basic Comparison of Lidar and Radar for Remote Sensing of Clouds written by Vernon Ellsworth Derr and published by . This book was released on 1978 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: Both radar and lidar have proved valuable in studying cloud microphysics and dynamics. Because of the large difference in wavelength, the two techniques have differing penetration capabilities and detection sensitivities. A "system-free" comparison of radar and lidar for several missions and many cloud types is presented to permit the optimum choice of technique for field studies of cloud formation, development, and precipitation.
Download or read book Feasibility of monitoring aerosol concentrations by 10 6 um backscatter lidar written by Gordon Lerfald and published by . This book was released on 1977 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Advances in Atmospheric Remote Sensing with Lidar written by Albert Ansmann and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 603 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lidar or laser radar, the depth-resolved remote measurement of atmospheric parameters with optical means, has become an important tool in the field of atmospheric and environmental remote sensing. In this volume the latest progress in the development of Lidar methods, experiments, and applications is described. The content is based on selected and thoroughly refereed papers presented at the 18th International Laser Radar Conference, Berlin, 22 - 26 July 1996. The book is divided into six parts which cover the topics of tropospheric aerosols and clouds, Lidar in space, wind, water vapor, troposheric trace gases and plumes, and stratospheric and mesospheric profiling. As a supplement to fundamental LIDAR textbooks this volume may serve as a guide through the blossoming field of modern Lidar techniques.
Download or read book 48 inch Lidar Aerosol Measurements Taken at the Langley Research Centre July 1991 to December 1992 written by David C. Woods and published by . This book was released on 1994 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presents lidar data taken between July 1991 and December 1992 using a ground-based 48-inch lidar instrument at the Langley Research Center in Hampton, Virginia. Seventy lidar profiles were obtained during this period, which began less than 1 month after the eruption of the Mount Pinatubo volcano in the Philippines. Plots of backscattering ratio as a function of altitude are presented for each data set along with tables containing numerical values of the backscattering ratio and backscattering coefficient versus altitude.
Download or read book Study on Multi layer aerosol Situations and of aerosol cloud Interactions written by Lucia-Timea Deaconu and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: One of the main objectives of this study is to analyze the consistency between the aerosol above clouds (AAC) retrievals from passive and active satellite measurements. We consider the method based on the passive polarization measurements provided by the POLDER instrument, the operational method developed for the space borne lidar CALIOP, and the CALIOP-based depolarization ratio method (DRM), for which we also propose a calibrated version. We perform a regional analysis and a global multi-annual analysis to provide robust statistics results. Our findings show good agreement between DRM and POLDER AOT retrievals (R2=0.68 at global scale). This result gives confidence in our ability to measure the properties of AAC. Differences occur when the aerosol and cloud layers are in contact. CALIOP operational method is largely underestimating the above cloud AOT, compared to the other two methods.The second objective is to study the impact of aerosols on the cloud properties and their radiative forcing, over the South Atlantic Ocean. We perform a synergy between CALIOP vertical profiles and POLDER retrievals, with collocated meteorological parameters. We performed radiative transfer calculations in the short- and longwave domains, and analyzed the effect of aerosol loading on the cloud properties and meteorology. We found that aerosols and water vapor effects could impact the cloud convection. Our results show that under large loads of AACs, clouds become optically thicker, with an increase in liquid water path of 20 g.m-2 and their cloud top altitudes are lower by 200 m, which may indicate a potential semi-direct effect of aerosols above clouds.
