Download or read book Study of Cloud Properties from Single scattering Radiative Forcing and Retrieval Perspectives written by Yong-Keun Lee and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation reports on three different yet related topics in light scattering computation, radiative transfer simulation, and remote sensing implementation, regarding the cloud properties and the retrieval of cloud properties from satellite-based infrared radiometric measurements. First, the errors associated with the use of circular cylinders as surrogates for hexagonal columns in computing the optical properties of pristine ice crystals at infrared (8-12 [micron]) wavelengths are investigated. It is found that the differences between the results for circular cylinders and hexagonal columns are on the order of a few percent at infrared wavelengths. Second, investigated in this dissertation are the outgoing broadband longwave and window channel radiances at the top-of-atmosphere under clear-sky conditions on the basis of the data acquired by the Cloud and the Earth's Radiant Energy System (CERES) instrument onboard the NASA Terra satellite platform. Based on the comparison of the observed broadband radiances with those obtained from rigorous radiative transfer simulations, it is found that the theoretical results tend to be larger than their measured counterparts. Extensive sensitivity studies regarding the uncertainties of various parameters were carried out. Within the considered uncertainties of various factors, the computed radiances are still larger than the observed radiances if thin cirrus clouds are excluded. Thus, a potential cause for the differences could be associated with the presence of thin cirrus clouds whose visible optical thickness is smaller than approximately 0.3. Third, presented in this dissertation is an illustration of the application of hyperspectral infrared channel observations to the retrieval of the cloud properties. Specifically, the hyperspectral measurements acquired from the Atmospheric Infrared Sounder (AIRS) aboard the NASA Aqua platform are used to infer cloud top pressure, effective cloud amount, cloud thermodynamic phase, cloud optical thickness, and the effective size of cloud particles. The AIRS-based retrievals are compared with the counterparts of the operational cloud products derived from the Moderate Resolution Imaging Spectroradiometer (MODIS). The two retrievals agree reasonably well except for the retrieved cloud effective particle size. Furthermore, the diurnal and seasonal contrasts of cloud properties are also investigated on the basis of the cloud properties retrieved from the AIRS data.

Download or read book An Analysis of Cloud Property Retrieval Using Infrared Sounder Data written by Bruce Anthony Wielicki and published by . This book was released on 1980 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Clouds Their Formation Optical Properties And Effects written by Peter Hobbs and published by Elsevier. This book was released on 2012-12-02 with total page 512 pages. Available in PDF, EPUB and Kindle. Book excerpt: Clouds: Their Formation, Optical Properties, and Effects deals with the formation of clouds as well as the theoretical and experimental aspects of their microphysical and optical properties. Discussions are grouped under the headings of structure of clouds, interaction of passive radiation with clouds, and interaction of active radiation with clouds. This book is organized into three sections and has 11 chapters. After analyzing the spatial and temporal scales involved in the formation and organization of clouds and precipitation, this text examines the microphysical measurement techniques used in probing the microstructure of clouds. The reader is then methodically introduced to the microstructure of atmospheric clouds and precipitation; the formation and structure of fog; and basic shortwave characteristics of “ideal clouds. The temporal behavior of clouds and their interaction with the radiation field are considered, along with the possible effects of cloud models in general circulation studies. The remaining chapters explore the light scattering properties of ice crystals and the radiative characteristics of ice clouds; the laser measurements in clouds; the transmission and reflectivity of ice clouds by active probing; and the theory of multiple scattering of laser beams in clouds. The book concludes by presenting the measurements of the temporal and spatial spreading of a blue-green pulse through clouds and fogs as a function of optical thickness and receiver field-of-view. This text will be helpful to advanced researchers and program managers in terms of reviewing the state of the art and identifying those areas requiring further research efforts.

Download or read book Cloud Forcing written by and published by . This book was released on 1990 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Cloud Scavenging Effects on Aerosol Radiative and Cloud nucleating Properties Final Technical Report written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The optical properties of aerosol particles are the controlling factors in determining direct aerosol radiative forcing. These optical properties depend on the chemical composition and size distribution of the aerosol particles, which can change due to various processes during the particles' lifetime in the atmosphere. Over the course of this project we have studied how cloud processing of atmospheric aerosol changes the aerosol optical properties. A counterflow virtual impactor was used to separate cloud drops from interstitial aerosol and parallel aerosol systems were used to measure the optical properties of the interstitial and cloud-scavenged aerosol. Specifically, aerosol light scattering, back-scattering and absorption were measured and used to derive radiatively significant parameters such as aerosol single scattering albedo and backscatter fraction for cloud-scavenged and interstitial aerosol. This data allows us to demonstrate that the radiative properties of cloud-processed aerosol can be quite different than pre-cloud aerosol. These differences can be used to improve the parameterization of aerosol forcing in climate models.

Download or read book Modeling Single Scattering and Radiative Properties of Cirrus Clouds written by and published by . This book was released on 1997 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The specific objective of this research has been the development and improvement of theoretical models to simulate the effect of nonsphericity on single scattering properties of cirrus cloud particles in the visible and infrared spectral regions. First, we have shown that using a matrix inversion scheme based on a special LU factorization rather than on the standard Gaussian elimination significantly improves the numerical stability of T-matrix computations for nonabsorbing and weakly absorbing nonspherical particles. Second, we use exact T-matrix computations and the Kirchhoff approximation to show that the delta function transmission peak predicted by the GO approximation for hexagonal ice crystals is an artifact of GO completely ignoring physical optics effects and must be convolved with the Fraunhofer pattern, thereby producing a phase function component with an angular profile similar to the standard diffraction component. Third, we have used the improved T-matrix method to compute the linear depolarization ration for polydispersions of randomly oriented ice spheroids, circular cylinders, and Chebyshev particles with sizes typical of young contrails. We have shown that ice crystals with effective radii as small as several tenths of a micron can already produce 3 exceeding 0.5 at visible wavelengths.

Download or read book Cloud Optics written by Alexander A. Kokhanovsky and published by Springer. This book was released on 2009-09-03 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt: Clouds affect the climate of the Earth, and they are an important factor in the weather. Therefore, their radiative properties must be understood in great detail. This book summarizes current knowledge on cloud optical properties, for example their ability to absorb, transmit, and reflect light, which depends on the clouds’ geometrical and microphysical characteristics such as sizes of droplets and crystals, their shapes, and structures. In addition, problems related to the image transfer through clouds and cloud remote sensing are addressed in this book in great detail. This book can be an important source of information on theoretical cloud optics for cloud physicists, meteorologists and optical engineers. All basic ideas of optics as related to scattering of light in clouds (e.g. Mie theory and radiative transfer) are considered in a self consistent way. Consequently, the book can also be a useful textbook to newcomers to the field.

Download or read book Radiative Transfer written by Anthony John Palubin and published by . This book was released on 1985 with total page 326 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Analysis of Cloud Microphysical Property Retrievals in a Vertically Stratified Cirrus Cloud written by Erik R. Olson and published by . This book was released on 2000 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Retrieval of Cloud Properties and Direct Testing of Cloud and Radiation Parameterizations Using ARM Observations written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The problems addressed by this work include cloud optical depth retrieval from satellite and surface data and 3D radiative transfer in dynamical models.

Download or read book Retrieval of Boundary Layer 3D Cloud Properties Using Scanning Cloud Radar and 3D Radiative Transfer written by and published by . This book was released on 2017 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: Retrievals of cloud optical and microphysical properties for boundary layer clouds, including those widely used by ASR investigators, frequently assume that clouds are sufficiently horizontally homogeneous that scattering and absorption (at all wavelengths) can be treated using one dimensional (1D) radiative transfer, and that differences in the field-of-view of different sensors are unimportant. Unfortunately, most boundary layer clouds are far from horizontally homogeneous, and numerous theoretical and observational studies show that the assumption of horizontal homogeneity leads to significant errors. The introduction of scanning cloud and precipitation radars at the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) program sites presents opportunities to move beyond the horizontally homogeneous assumption. The primary objective of this project was to develop a 3D retrieval for warm-phase (liquid only) boundary layer cloud microphysical properties, and to assess errors in current 1D (non-scanning) approaches. Specific research activities also involved examination of the diurnal cycle of hydrometeors as viewed by ARM cloud radar, and continued assessment of precipitation impacts on retrievals of cloud liquid water path using passive microwaves.

Download or read book A Model Perspective on Cloud Radiative Forcing written by Gerald L. Potter and published by . This book was released on 1993 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Development and Validation of Improved Techniques for Cloud Property Retrieval from Environmental Satellites written by Gary B. Gustafson and published by . This book was released on 2000 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: A basic research program was conducted for the Air Force Research Laboratory, consisting of three tasks: (1) develop extensible cloud property retrieval algorithms suitable for expanding existing cloud analysis capabilities to utilize data from new and future environmental satellite sensing systems; (2) develop advanced algorithms for retrieval of cloud properties that are insufficiently resolved to satisfy Air Force requirements using existing techniques; and (3) validate cloud property retrieval algorithms using real data from existing meteorological satellite platforms. Under task 1 a series of algorithms developed under previous AFRL programs were modified to expand capabilities in several areas including improved transmissive cirrus detection and classification, cloud phase retrieval, snow/cloud discrimination, and transition across the terminator. In task 2 new capabilities were developed to retrieve cloud radiative and microphysical properties from multispectral data available from environmental satellites including the newly launched MODIS. Under task 3 the new algorithms were implemented in software and applied to real data acquired from the GOES 8 satellite in support of two field programs conducted or supported by AFRL.

Download or read book The Interpretation of Remotely Sensed Cloud Properties from a Model Parameterization Perspective written by and published by . This book was released on 1995 with total page 2 pages. Available in PDF, EPUB and Kindle. Book excerpt: The goals of ISCCP and FIRE are, broadly speaking, to provide methods for the retrieval of cloud properties from satellites, and to improve cloud radiation models and the parameterization of clouds in GCMs. This study suggests a direction for GCM cloud parameterizations based on analysis of Landsat and ISCCP satellite data. For low level single layer clouds it is found that the mean retrieved liquid water pathe in cloudy pixels is essentially invariant to the cloud fraction, at least in the range 0.2 - 0.8. This result is very important since it allows the cloud fraction to be estimated if the mean liquid water path of cloud in a general circulation model gridcell is known. 3 figs.

Download or read book Diagnostic Study on Retrieving Bulk Microphysical Properties of Low level Stratiform Clouds and Its Implication on Climate Research written by and published by . This book was released on 1998 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: The importance of low-level stratiform clouds to the planetary radiation balance is due to their persistence and coverage, and their effect on the planetary albedo. The vertical distribution of liquid water in these clouds is pertinent to many applications in atmospheric research. As a result, some cloud retrieval techniques have been developed with the assumptions, such as an adiabatic condition, no loss of liquid water via drizzle and/or a large liquid water path.

Download or read book A Modeling Perspective on Cloud Radiative Forcing written by and published by . This book was released on 1993 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Cloud Physical Properties Retrieval for Climate Studies Using SEVIRI and AVHRR Data written by Robert A. Roebeling and published by . This book was released on 2008* with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt: