Download or read book Assessing the Performance of Several Modis Level 2 Cloud and Aerosol Products Against a Surface Based Polarization Cloud Lidar at Fairbanks AK written by Patrick Cobb and published by . This book was released on 2008 with total page 450 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Global Circulation Models (GCMs) currently suffer from inadequate cloud and aerosol parameterizations due to a shortage of information regarding how clouds and aerosols are globally distributed in space and time. Although surface and airborne instruments can offer reliable cloud and aerosol measurements, such methods are expensive, and their scope is rather limited. Satellite instruments, such as the MODerate resolution Imaging Spectroradiometer (MODIS), may provide an alternative. MODIS measures spectral radiance in thirty-six discreet spectral bands. A variety of cloud and aerosol properties are derived at the pixel scale from these measurements using algorithms developed from radiative transfer theory. A comprehensive validation campaign is underway to assess the quality of these data in hopes that it can be assimilated into the GCMs. This thesis provides one such study comparing the MODIS cloud mask, cloud top properties, cloud thermodynamic phase and aerosol type with overlapping surface data from a polarization cloud lidar at Fairbanks, AK. Most of the sample is comprised of cirrus clouds, which are difficult to detect with satellites. Results are mixed, but are generally consistent with past studies. The MODIS products are fairly dependable, but the algorithms could be improved, especially over the polar regions"--Leaf iii.
Download or read book EOS Data Products Handbook written by Michael D. King and published by . This book was released on 2003 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt: Description of the data products that will be produced from the named scientific missions.
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 Cloud and Aerosol Optics by Polarized Micro Pulse Lidar and Ground Based Measurements of Zenith Radiance written by Rodrigo Delgadillo and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Clouds impact Earth's climate through cloud transmission and reflection properties. Clouds reflect approximately 15 percent of the incoming solar radiation at the top of the atmosphere. A key cloud radiative variable is cloud optical depth, which gives information about how much light is transmitted through a cloud. Historically, remote measurements of cloud optical depth have been limited to uniform overcast conditions and had low temporal and spatial resolution. We present a novel method to measure cloud optical depth for coastal regions from spectral zenith radiance measurements for optically thin clouds, which removes some of these limitations. Our measurement site is part of South Florida's Cloud-Aerosol-Rain Observatory (CAROb), located on Virginia Key, FL (6 km from Miami). This work is based on Marshak et al.'s [1] method for finding cloud optical depth from vegetative sites that provide a strong spectral contrast between red and near infrared surface albedo. However, given the unique nature of our site, which contains water, vegetation, beach, and urban surface types, we found no such spectral contrast at those wavelength pairs. We measured albedo, with hyperspectral resolution, for different surface types around our measurement site to estimate the effective spectral albedo for the area centered on the site with a 5km radius. From this analysis, we found the best possible albedo contrast (573.9 and 673.1 nm) for our site. We tested the derived cloud optical depth from zenith radiance at these two wavelengths against a concurrently running polarized micro pulse LIDAR (MPL) and found good agreement.
Download or read book Observations of Aerosol and Liquid water Clouds with Dual Field of View Polarization Lidar written by Cristofer Andrés Jiménez Jiménez and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book EOS Science Plan written by and published by . This book was released on 1999 with total page 406 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Climate Intervention written by National Research Council and published by National Academies Press. This book was released on 2015-06-23 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt: The growing problem of changing environmental conditions caused by climate destabilization is well recognized as one of the defining issues of our time. The root problem is greenhouse gas emissions, and the fundamental solution is curbing those emissions. Climate geoengineering has often been considered to be a "last-ditch" response to climate change, to be used only if climate change damage should produce extreme hardship. Although the likelihood of eventually needing to resort to these efforts grows with every year of inaction on emissions control, there is a lack of information on these ways of potentially intervening in the climate system. As one of a two-book report, this volume of Climate Intervention discusses albedo modification - changing the fraction of incoming solar radiation that reaches the surface. This approach would deliberately modify the energy budget of Earth to produce a cooling designed to compensate for some of the effects of warming associated with greenhouse gas increases. The prospect of large-scale albedo modification raises political and governance issues at national and global levels, as well as ethical concerns. Climate Intervention: Reflecting Sunlight to Cool Earth discusses some of the social, political, and legal issues surrounding these proposed techniques. It is far easier to modify Earth's albedo than to determine whether it should be done or what the consequences might be of such an action. One serious concern is that such an action could be unilaterally undertaken by a small nation or smaller entity for its own benefit without international sanction and regardless of international consequences. Transparency in discussing this subject is critical. In the spirit of that transparency, Climate Intervention: Reflecting Sunlight to Cool Earth was based on peer-reviewed literature and the judgments of the authoring committee; no new research was done as part of this study and all data and information used are from entirely open sources. By helping to bring light to this topic area, this book will help leaders to be far more knowledgeable about the consequences of albedo modification approaches before they face a decision whether or not to use them.
Download or read book Best Practices Handbook for the Collection and Use of Solar Resource Data for Solar Energy Applications written by M. Sengupta and published by . This book was released on 2013 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Evaluation of Polarization Diversity Lidar for Cloud Physics Research written by Kenneth Sassen and published by . This book was released on 1976 with total page 784 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A History of Grace Anglican Church Arthur Ontario 1844 1975 written by and published by . This book was released on 1975* with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Real Effect Or Artifact of Cloud Cover on Aerosol Optical Thickness written by and published by . This book was released on 2005 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aerosol measurements over the Southern Great Plains (SGP) Cloud And Radiation Test bed (CART) site under Department of Energy's (DOE) Atmospheric Radiation Measurement (ARM) program characterize the temporal variability, vertical distribution, and optical properties of aerosols in the region. They were made by the Cimel sunphotometer and Multifilter Rotating Shadow-band Radiometer (MFRSR), Raman Lidar, In situ Aerosol Profiling (IAP) flights, and the Aerosol Observing System (AOS). The spatial variability of aerosols relies a network of MFRSR at the Central Facility (CF) and Extended Facilities (EF), together with satellite remote sensing. The current state-of-art satellite-based estimates over land--e.g., MODerate resolution Imaging Scanner (MODIS) aerosol optical thickness--still suffer from large uncertainties. Contamination due to sub-pixel and/or thin cirrus clouds is believed to be one of the major sources of uncertainties. Retrievals near clouds are discouraged to use, which reduces considerably the amount of useful data. In this regard, cloud is considered as an artifact. However, cloud could have a real impact on AOT by changing humidity, which affects aerosol through the aerosol swelling effect. As a preliminary study, we first investigate the effects of cloud cover and humidity on the retrievals of AOT from ground-based Cimel sunphotometer measurements, in order to help us sort out the real influence and artifact. In general, it is very difficult to verify and quantify the effects of cloud on satellite retrieval of aerosol quantities. Speculation and warning of cloud contamination have been made whenever there is a correlation between the retrieved AOT and cloud fraction or their spatial variabilities, while it has also been argued that aerosol humidification effect (AHE) might be at work. The ample measurements available from ARM over the SGP region may allow us to unravel this complex issue. Our ultimate goals are to (1) evaluate various effects on the retrievals of AOT from both satellite and ground sensors; (2) separate artifact from real effect; (3) create ''clean'' aerosol products for studying their direct and indirect effect. Presented are some very preliminary findings.
Download or read book Next Generation Earth System Prediction written by National Academies of Sciences, Engineering, and Medicine and published by National Academies Press. This book was released on 2016-08-22 with total page 351 pages. Available in PDF, EPUB and Kindle. Book excerpt: As the nation's economic activities, security concerns, and stewardship of natural resources become increasingly complex and globally interrelated, they become ever more sensitive to adverse impacts from weather, climate, and other natural phenomena. For several decades, forecasts with lead times of a few days for weather and other environmental phenomena have yielded valuable information to improve decision-making across all sectors of society. Developing the capability to forecast environmental conditions and disruptive events several weeks and months in advance could dramatically increase the value and benefit of environmental predictions, saving lives, protecting property, increasing economic vitality, protecting the environment, and informing policy choices. Over the past decade, the ability to forecast weather and climate conditions on subseasonal to seasonal (S2S) timescales, i.e., two to fifty-two weeks in advance, has improved substantially. Although significant progress has been made, much work remains to make S2S predictions skillful enough, as well as optimally tailored and communicated, to enable widespread use. Next Generation Earth System Predictions presents a ten-year U.S. research agenda that increases the nation's S2S research and modeling capability, advances S2S forecasting, and aids in decision making at medium and extended lead times.
Download or read book MTPE EOS Reference Handbook written by and published by . This book was released on 1995 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Earth Observer written by and published by . This book was released on 2000 with total page 280 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Final Technical Report Cloud and Radiation Testbed CART Raman Lidar Measurement of Atmospheric Aerosols for the Atmospheric Radiation Measurement ARM Program written by and published by . This book was released on 2002 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: Vertical profiles of aerosol extinction are required for determination of the effects of aerosols on the clear-sky radiative flux. Since recent studies have demonstrated the inability to compute these profiles on surface aerosol measurements alone, vertical profiles of aerosol optical properties must be acquired to compute aerosol radiative effects throughout the entire atmospheric column. Following the recommendation of the ARM Aerosol Working Group, the investigator developed, evaluated, and implemented algorithms for the CART Raman Lidar to provide profiles of aerosol extinction and backscattering. By virtue of its ability to measure vertical profiles of both aerosol extinction and water vapor simultaneously in the same scattering volume, we used the resulting profiles from the CART Raman Lidar to investigate the impact of water vapor and relative humidity on aerosol extinction throughout the column on a continuous and routine basis. The investigator used these the CART Raman Lidar aerosol extinction and backscattering profiles to evaluate the vertical variability of aerosol extinction and the extinction/backscatter ratio over the ARM SGP site.
Download or read book Multiple field of view Lidar Tests written by and published by . This book was released on 1996 with total page 85 pages. Available in PDF, EPUB and Kindle. Book excerpt: Describes an inversion method for lidar measurements made at multiple fields of view (MFOV). The solutions give the profiles of the visible and infrared aerosol extinction coefficients along the lidar axis without the need for a boundary value nor a backscatter-to-extinction relation. The solutions are compared with in-situ data obtained in two different field experiments performed in fog and clouds. The comparison analysis demonstrates the capabilities of the MFOV lidar in providing the necessary inputs for on-site assessment of the performance of military electro-optical systems in adverse weather. A series of recommendations is presented, based on the experimental results and a detailed design study, regarding the development of a compact, ruggedized, eye-safe MFOV lidar suitable for field testing in true operational conditions.
Download or read book Thriving on Our Changing Planet A Decadal Strategy for Earth Observation from Space written by National Academies of Sciences, Engineering, and Medicine and published by National Academies Press. This book was released on 2019-06-18 with total page 29 pages. Available in PDF, EPUB and Kindle. Book excerpt: We live on a dynamic Earth shaped by both natural processes and the impacts of humans on their environment. It is in our collective interest to observe and understand our planet, and to predict future behavior to the extent possible, in order to effectively manage resources, successfully respond to threats from natural and human-induced environmental change, and capitalize on the opportunities â€" social, economic, security, and more â€" that such knowledge can bring. By continuously monitoring and exploring Earth, developing a deep understanding of its evolving behavior, and characterizing the processes that shape and reshape the environment in which we live, we not only advance knowledge and basic discovery about our planet, but we further develop the foundation upon which benefits to society are built. Thriving on Our Changing Planet: A Decadal Strategy for Earth Observation from Space (National Academies Press, 2018) provides detailed guidance on how relevant federal agencies can ensure that the United States receives the maximum benefit from its investments in Earth observations from space, while operating within realistic cost constraints. This short booklet, designed to be accessible to the general public, provides a summary of the key ideas and recommendations from the full decadal survey report.
