Download or read book Anthropogenic Sulfate Clouds and Climate Forcing written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-08-20 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt: This research work is a joint effort between research groups at the Battelle Pacific Northwest Laboratory, Virginia Tech University, Georgia Institute of Technology, Brookhaven National Laboratory, and Texas A&M University. It has been jointly sponsored by the National Aeronautics and Space Administration, the U.S. Department of Energy, and the U.S. Environmental Protection Agency. In this research, a detailed tropospheric aerosol-chemistry model that predicts oxidant concentrations as well as concentrations of sulfur dioxide and sulfate aerosols has been coupled to a general circulation model that distinguishes between cloud water mass and cloud droplet number. The coupled model system has been first validated and then used to estimate the radiative impact of anthropogenic sulfur emissions. Both the direct radiative impact of the aerosols and their indirect impact through their influence on cloud droplet number are represented by distinguishing between sulfuric acid vapor and fresh and aged sulfate aerosols, and by parameterizing cloud droplet nucleation in terms of vertical velocity and the number concentration of aged sulfur aerosols. Natural sulfate aerosols, dust, and carbonaceous and nitrate aerosols and their influence on the radiative impact of anthropogenic sulfate aerosols, through competition as cloud condensation nuclei, will also be simulated. Parallel simulations with and without anthropogenic sulfur emissions are performed for a global domain. The objectives of the research are: To couple a state-of-the-art tropospheric aerosol-chemistry model with a global climate model. To use field and satellite measurements to evaluate the treatment of tropospheric chemistry and aerosol physics in the coupled model. To use the coupled model to simulate the radiative (and ultimately climatic) impacts of anthropogenic sulfur emissions. Ghan, Steven J. Unspecified Center NAGw-3735...
Download or read book A Plan for a Research Program on Aerosol Radiative Forcing and Climate Change written by Panel on Aerosol Radiative Forcing and Climate Change and published by National Academies Press. This book was released on 1996-05-01 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book recommends the initiation of an "integrated" research program to study the role of aerosols in the predicted global climate change. Current understanding suggest that, even now, aerosols, primarily from anthropogenic sources, may be reducing the rate of warming caused by greenhouse gas emissions. In addition to specific research recommendations, this book forcefully argues for two kinds of research program integration: integration of the individual laboratory, field, and theoretical research activities and an integrated management structure that involves all of the concerned federal agencies.
Download or read book A Plan for a Research Program on Aerosol Radiative Forcing and Climate Change written by National Research Council and published by National Academies Press. This book was released on 1996-04-17 with total page 179 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book recommends the initiation of an "integrated" research program to study the role of aerosols in the predicted global climate change. Current understanding suggest that, even now, aerosols, primarily from anthropogenic sources, may be reducing the rate of warming caused by greenhouse gas emissions. In addition to specific research recommendations, this book forcefully argues for two kinds of research program integration: integration of the individual laboratory, field, and theoretical research activities and an integrated management structure that involves all of the concerned federal agencies.
Download or read book Quantifying and Minimizing Uncertainty of Climate Forcing by Anthropogenic Aerosols written by J. E. Penner and published by . This book was released on 1993 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Anthropogenic Sulfate and Organic Aerosols CCN and Cloud Project Concentration at a Marine Site written by and published by . This book was released on 1993 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: The need to establish the relationships between the number concentration of cloud droplets, cloud condensation nuclei (CCN), and the mass concentrations of major aerosol species has been heightened by the results of recent modeling studies suggesting that anthropogenic sulfate and biomass smoke aerosols may cause a globally averaged climate forcing comparable in magnitude but opposite in sign to the forcing due to ''greenhouse'' gases. In this paper we present the results of measurements of nonseasalt (nss) sulfate and organic carbon mass concentrations and mass size distributions, CCN, and cloud droplet number concentrations obtained in 1991 and 1992 on El Yunque peak, Puerto Rico . This peak (18°19N, 65°45W; elevation 1000 m) is located the eastern end of the island, directly exposed to the ocean winds and frequently covered with clouds. Our results show that although CCN number concentrations (measured at 0.5% supersaturation) and nss sulfate mass concentrations are significantly correlated at this site, estimates based on measured mass size distributions of organic and sulfate aerosols indicate that the organic aerosols may account for the majority of CCN number concentrations. Droplet concentrations in the cumulus clouds do not show a discernible trend with nss sulfate mass concentrations. In stratocumulus clouds a small increase in droplet concentrations with nss sulfate mass concentrations was observed.
Download or read book Clouds Chemistry and Climate written by Paul J. Crutzen and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 337 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this NATO Advanced Research Workshop was to discuss our current understanding of the role of clouds in climate and chemistry. The range of topics dis cussed during the workshop included: modeling of clouds in GCMs; observations of the cloud micro physical properties; the water vapor cycle; troposphere-stratosphere exchange; role of in-cloud transport in tropospheric ozone; regulation of current and paleo climate by clouds; and anthropogenic sulfate aerosols and modification of cloud properties. The essence of the discussions is captured in the accompanying summary by the rapporteurs and the chapters by some of the speakers. The underlying message is that significant progress has been made, resulting in exciting new developments in our perception of the role of clouds in the global system . .. The tropical convective-cirrus cloud systems emerge as a major influence on the climate system. Micro physical processes, such as the rate of precipitation and re evaporation of ice particles, seem to regulate the large scale vertical distribution of water vapor which is the dominant greenhouse gas. Water vapor data collected during the Central Equatorial Pacific Experiment (CEPEX), document the large moistening effect of deep convection on scales of thousands of kilometers. A major chemical finding in the same region was the observation of extremely low ozone 8 volume mixing ratios of less than 10- in the entire troposphere of the central equatorial Pacific extending over a distance of about 2000 km. This finding establishes the Pacific as a major chemical sink region for tropospheric ozone.
Download or read book Climate Change Science written by National Research Council and published by National Academies Press. This book was released on 2001-06-28 with total page 41 pages. Available in PDF, EPUB and Kindle. Book excerpt: The warming of the Earth has been the subject of intense debate and concern for many scientists, policy-makers, and citizens for at least the past decade. Climate Change Science: An Analysis of Some Key Questions, a new report by a committee of the National Research Council, characterizes the global warming trend over the last 100 years, and examines what may be in store for the 21st century and the extent to which warming may be attributable to human activity.
Download or read book Aerosol Forcing of Climate written by R. J. Charlson and published by . This book was released on 1995-08-24 with total page 460 pages. Available in PDF, EPUB and Kindle. Book excerpt: Global climate change as a consequence of anthropogenic changes in the chemical composition of the atmosphere poses scientific questions of a nature and interdisciplinary scope that are unprecedented. Uncertainties in the climate forecast are large and thus far have hampered the establishment of a clear world plan for preventing or mitigating against unacceptable effects. The forecast of global and regional climate changes depends upon the development of a sound understanding of the factors that change the global heat balance and thus influence the climate. Changes in heat balance due to anthropogenic or externally imposed changes in the chemical composition of the atmosphere are referred to as forcings. While the uncertainties in the global mean greenhouse-gas forcing are not negligible (??? 15%), uncertainties in forcings by changes in the atmospheric aerosol and in clouds are much larger, and in some cases even include uncertainty in the sign of the forcing. Reductionist science, with its compartmentalized disciplines, has not coped effectively with the scientific problems of aerosols and their effects, largely because of a need for simultaneous consideration of chemical processes, chemical properties, physical properties, and a wide variety of physical processes and consequences. In the case of natural aerosols and their effects on clouds, it is even necessary to include studies of microbiology and of biochemistry. This volume ? the record of intense, interdisciplinary debate between atmospheric chemists, meteorologists, physicists, and biogeochemists - considers the subset of climate forcings due to atmospheric aerosols, with particular emphasis on integrating the necessary disciplinary components. It is truly unique in its interdisciplinary approach. The information contained in the overview papers and summary reports will be of interest to policymakers and scientists alike. Goal of this Dahlem Workshop to assess the controlling factors, geographic and temporal variations of the radiative properties of atmospheric aerosols, and to examine the extent to which their forcing through direct and indirect effects counteracts greenhouse-gas forcing on regional and global climate.
Download or read book Surface Temperature Reconstructions for the Last 2 000 Years written by National Research Council and published by National Academies Press. This book was released on 2007-01-05 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt: In response to a request from Congress, Surface Temperature Reconstructions for the Last 2,000 Years assesses the state of scientific efforts to reconstruct surface temperature records for Earth during approximately the last 2,000 years and the implications of these efforts for our understanding of global climate change. Because widespread, reliable temperature records are available only for the last 150 years, scientists estimate temperatures in the more distant past by analyzing "proxy evidence," which includes tree rings, corals, ocean and lake sediments, cave deposits, ice cores, boreholes, and glaciers. Starting in the late 1990s, scientists began using sophisticated methods to combine proxy evidence from many different locations in an effort to estimate surface temperature changes during the last few hundred to few thousand years. This book is an important resource in helping to understand the intricacies of global climate change.
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 Radiative Forcing of Climate Change written by National Research Council and published by National Academies Press. This book was released on 2005-03-25 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt: Changes in climate are driven by natural and human-induced perturbations of the Earth's energy balance. These climate drivers or "forcings" include variations in greenhouse gases, aerosols, land use, and the amount of energy Earth receives from the Sun. Although climate throughout Earth's history has varied from "snowball" conditions with global ice cover to "hothouse" conditions when glaciers all but disappeared, the climate over the past 10,000 years has been remarkably stable and favorable to human civilization. Increasing evidence points to a large human impact on global climate over the past century. The report reviews current knowledge of climate forcings and recommends critical research needed to improve understanding. Whereas emphasis to date has been on how these climate forcings affect global mean temperature, the report finds that regional variation and climate impacts other than temperature deserve increased attention.
Download or read book Chemistry of the Natural Atmosphere written by Peter Warneck and published by Elsevier. This book was released on 1999-10-29 with total page 947 pages. Available in PDF, EPUB and Kindle. Book excerpt: Knowledge of thc chemical behavior of trace compounds in the atmosphere has grown steadily, and sometimes even spectacularly, in recent decades. These developments have led to the emergence of atmospheric chemistry as a new branch of science. This book covers all aspects of atmospheric chemistry on a global scale, integrating information from chemistry and geochemistry, physics, and biology to provide a unified account. For each atmospheric constituent of interest, the text summarizes the principal observations on global distribution, chemical reactions, natural and anthropogenic sources, and physical removal processes. Coverage includes processes in the gas phase, in aerosols and c1ouds, and in precipitation, as well as biogeochemical cycles and the evolution of the atmosphere. Chemistry of the Natural Atmosphere, Second Edition, will serve as a textbook for senior undergraduate and graduate courses, and as an essential reference for atmospheric chemists, meteorologists, and anyone studying the biogeochemical cycles of trace gases.* Updated extensively from the highly respected first edition * Treats the global-scale chemistry and distribution of atmospheric trace constituents * Emphasizes observations and their interpretation* Provides background on transport and reaction kinetics for interpretation of observational data* Includes chemistry in the gas phase and in aerosols and clouds* Details chemical reaction pathways for the most important trace constituents* Describes pertinent biogeochemical cycles* Written by an author with more than 40 years of research experience in atmospheric chemistry
Download or read book Climate Effects of Anthropogenic Sulfate written by and published by . This book was released on 1993 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this paper, we use a more comprehensive approach by coupling a climate model with a 3-D global chemistry model to investigate the forcing by anthropogenic aerosol sulfate. The chemistry model treats the global-scale transport, transformation, and removal of SO2, DMS and H2SO4 species in the atmosphere. The mass concentration of anthropogenic sulfate from fossil fuel combustion and biomass burning is calculated in the chemistry model and provided to the climate model where it affects the shortwave radiation. We also investigate the effect, with cloud nucleation parameterized in terms of local aerosol number, sulfate mass concentration and updraft velocity. Our simulations indicate that anthropogenic sulfate may result in important increases in reflected solar radiation, which would mask locally the radiative forcing from increased greenhouse gases. Uncertainties in these results will be discussed.
Download or read book Atmospheric Aerosols written by S. Twomey and published by Elsevier Science & Technology. This book was released on 1977 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt: Good,No Highlights,No Markup,all pages are intact, Slight Shelfwear,may have the corners slightly dented, may have slight color changes/slightly damaged spine.
Download or read book Aerosol Cloud Interactions from Urban Regional to Global Scales written by Yuan Wang and published by Springer. This book was released on 2015-05-05 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt: The studies in this dissertation aim at advancing our scientific understandings about physical processes involved in the aerosol-cloud-precipitation interaction and quantitatively assessing the impacts of aerosols on the cloud systems with diverse scales over the globe on the basis of the observational data analysis and various modeling studies. As recognized in the Fifth Assessment Report by the Inter-government Panel on Climate Change, the magnitude of radiative forcing by atmospheric aerosols is highly uncertain, representing the largest uncertainty in projections of future climate by anthropogenic activities. By using a newly implemented cloud microphysical scheme in the cloud-resolving model, the thesis assesses aerosol-cloud interaction for distinct weather systems, ranging from individual cumulus to mesoscale convective systems. This thesis also introduces a novel hierarchical modeling approach that solves a long outstanding mismatch between simulations by regional weather models and global climate models in the climate modeling community. More importantly, the thesis provides key scientific solutions to several challenging questions in climate science, including the global impacts of the Asian pollution. As scientists wrestle with the complexities of climate change in response to varied anthropogenic forcing, perhaps no problem is more challenging than the understanding of the impacts of atmospheric aerosols from air pollution on clouds and the global circulation.
Download or read book Global Change Research written by United States. Congress. Senate. Committee on Commerce, Science, and Transportation and published by . This book was released on 1992 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Aerosol Cloud Climate Interactions written by Peter V. Hobbs and published by Academic Press. This book was released on 1993-07-22 with total page 259 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aerosol and clouds play important roles in determining the earth's climate, in ways that we are only beginning to comprehend. In conjunction with molecular scattering from gases, aerosol and clouds determine in part what fraction of solar radiation reaches the earth's surface, and what fraction of the longwave radiation from the earth escapes to space. This book provides an overview of the latest research on atmospheric aerosol and clouds and their effects on global climate. Subjects reviewed include the direct and indirect effects of aerosol on climate, the radiative properties of clouds and their effects on the Earth's radiation balance, the incorporation of cloud effects in numerical weather prediction models, and stratospheric aerosol and clouds.
