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 Quantifying and Minimizing Uncertainty of Climate Forcing by Anthropogenic Aerosols written by and published by . This book was released on 1993 with total page 53 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Quantifying and Minimizing Uncertainty of Climate Forcing by Anthropogenic Aerosols written by United States. Department of Energy. Office of Energy Research and published by . This book was released on 1993 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Quantifying and Minimizing Uncertainty of Climate Forcing by Anthropogenic Aerosols written by and published by . This book was released on 1993 with total page 53 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 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 1996-05-17 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 Radiative Forcing of Climate Change written by National Research Council and published by National Academies Press. This book was released on 2005-04-25 with total page 223 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 Aerosols and Climate written by Ken S. Carslaw and published by Elsevier. This book was released on 2022-08-19 with total page 856 pages. Available in PDF, EPUB and Kindle. Book excerpt: The ever-diversifying field of aerosol effects on climate is comprehensively presented here, describing the strong connection between fundamental research and model applications in a way that will allow both experienced researchers and those new to the field to gain an understanding of a wide range of topics. The material is consistently presented at three levels for each topic: (i) an accessible "quick read" of the essentials, (ii) a more detailed description, and (iii) a section dedicated to how the processes are handled in models. The modelling section in each chapter summarizes the current level of knowledge and what the gaps in this understanding mean for the effects of aerosols on climate, enabling readers to quickly understand how new research fits into established knowledge. Definitions, case studies, reference data, and examples are included throughout. Aerosols and Climate is a vital resource for graduate students, postdoctoral researchers, senior researchers, and lecturers in departments of atmospheric science, meteorology, engineering, and environment. It will also be of interest to those working in operational centers and policy-facing organizations, providing strong reference material on the current state of knowledge. Includes a section in each chapter that focuses on the treatment of relevant aerosol processes in climate models Provides clear exposition of the challenges in understanding and reducing persistent gaps in knowledge and uncertainties in the field of aerosol-climate interaction, going beyond the fundamentals and existing knowledge Authored by experts in modeling and aerosol processes, analysis or observations to ensure accessibility and balance

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 Coupling Satellite and Ground Based Instruments to Map Climate Forcing by Anthropogenic Aerosols written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-15 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: Climate forcing by anthropogenic aerosols is a significant but highly uncertain factor in global climate change. Only satellites can offer the global coverage essential to reducing this uncertainty; however, satellite measurements must be coupled with correlative, in situ measurements both to constrain the aerosol optical properties required in satellite retrieval algorithms and to provide chemical identification of aerosol sources. This grant funded the first two years of a three-year project which seeks to develop methodologies for combining spaceborne lidar with in-situ aerosol data sets to improve estimates of direct aerosol climate forcing. Progress under this two-year grant consisted in the development and deployment of a new in-situ capability for measuring aerosol 180' backscatter and the extinction-to-backscatter ratio. This new measurement capacity allows definitive lidar/in-situ comparisons and improves our ability to interpret lidar data in terms of climatically relevant quantities such as the extinction coefficient and optical depth. Measurements were made along the coast of Washington State, in Central Illinois, over the Indian Ocean, and in the Central Pacific. Thus, this research, combined with previous measurements by others, is rapidly building toward a global data set of extinction-to-backscatter ratio for key aerosol types. Such information will be critical to interpreting lidar data from the upcoming PICASSO-CENA, or P-C, satellite mission. Another aspect of this project is to investigate innovative ways to couple the lidar-satellite signal with targeted in-situ measurements toward a direct determination of aerosol forcing. This aspect is progressing in collaboration with NASA Langley's P-C lidar simulator and radiative transfer modeling by the University of Lille, France. Charlson, Robert J. and Anderson, Theodore L. and Hostetler, Chris (Technical Monitor) Langley Research Center Rept-61-8393

Download or read book Coupling Satellite and Ground Based Instruments to Map Climate Forcing by Anthropogenic Aerosol written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-16 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: Climate forcing by anthropogenic aerosols is a significant but highly uncertain factor in global climate change. Only satellites can offer the global coverage essential to reducing this uncertainty; however, satellite measurements must be coupled with correlative, in situ measurements both to constrain the aerosol optical properties required in satellite retrieval algorithms and to provide chemical identification of aerosol sources. This grant funded the third year of a three-year project which seeks to develop methodologies for combining spaceborne lidar with in-situ aerosol data sets to improve estimates of direct aerosol climate forcing. Progress under this one-year grant consisted in analysis and publication of field studies using a new in-situ capability for measuring aerosol 180 deg backscatter and the extinction-to-backscatter ratio. This new measurement capacity allows definitive lidar/in-situ comparisons and improves our ability to interpret lidar data in terms of climatically relevant quantities such as the extinction coefficient and optical depth. Analyzed data consisted of measurements made along the coast of Washington State, in Central Illinois, over the Indian Ocean, and in the Central Pacific. Thus, this research, combined with previous measurements by others, is rapidly building toward a global data set of extinction-to-backscatter ratio for key aerosol types. Such information will be critical to interpreting lidar data from the upcoming PICASSO-CENA, or P-C, satellite mission. Another aspect of this project is to investigate innovative ways to couple the lidar-satellite signal with target in-situ measurements toward a direct determination of aerosol forcing. This aspect is progressing in collaboration with NASA Langley's P-C lidar simulator. Charlson, Robert J. and Anderson, Theodore L. and Hostetler, Chris (Technical Monitor) Langley Research Center

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 Atmospheric Aerosol Properties and Climate Impacts written by Mian Chin and published by DIANE Publishing. This book was released on 2009-05 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Synthesis and Assessment Product (SAP) critically reviews current knowledge about global distributions and properties of atmospheric aerosols, as they relate to aerosol impacts on climate. It assesses possible next steps aimed at substantially reducing uncertainties in aerosol radiative forcing estimates. Current measurement techniques and modeling approaches are summarized, providing context. The objectives of this report are: (1) to promote a consensus about the knowledge base for climate change decision support; and (2) to provide a synthesis and integration of the current knowledge of the climate-relevant impacts of anthropogenic aerosols. Illustrations.

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 Climate Stabilization Targets written by National Research Council and published by National Academies Press. This book was released on 2011-02-11 with total page 298 pages. Available in PDF, EPUB and Kindle. Book excerpt: Emissions of carbon dioxide from the burning of fossil fuels have ushered in a new epoch where human activities will largely determine the evolution of Earth's climate. Because carbon dioxide in the atmosphere is long lived, it can effectively lock the Earth and future generations into a range of impacts, some of which could become very severe. Emissions reductions decisions made today matter in determining impacts experienced not just over the next few decades, but in the coming centuries and millennia. According to Climate Stabilization Targets: Emissions, Concentrations, and Impacts Over Decades to Millennia, important policy decisions can be informed by recent advances in climate science that quantify the relationships between increases in carbon dioxide and global warming, related climate changes, and resulting impacts, such as changes in streamflow, wildfires, crop productivity, extreme hot summers, and sea level rise. One way to inform these choices is to consider the projected climate changes and impacts that would occur if greenhouse gases in the atmosphere were stabilized at a particular concentration level. The book quantifies the outcomes of different stabilization targets for greenhouse gas concentrations using analyses and information drawn from the scientific literature. Although it does not recommend or justify any particular stabilization target, it does provide important scientific insights about the relationships among emissions, greenhouse gas concentrations, temperatures, and impacts. Climate Stabilization Targets emphasizes the importance of 21st century choices regarding long-term climate stabilization. It is a useful resource for scientists, educators and policy makers, among others.

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.

Download or read book Investigation of Aerosol Sources Lifetime and Radiative Forcing Through Multi Instrument Data Assimilation written by Juli Irene Rubin and published by . This book was released on 2012 with total page 426 pages. Available in PDF, EPUB and Kindle. Book excerpt: Global-scale atmospheric models play an important role in predicting atmospheric aerosol and the corresponding radiative forcing. Although atmospheric models are important tools, there is large uncertainty associated with aerosol predictions due to uncertainty in aerosol representation within the models. As a result, aerosols and their influence on the Earth's energy balance are considered one of the largest uncertainties in understanding climate change. Given the importance of simulating aerosol for understanding global climate change, it is evident that alternative methods are needed to reduce the effect of the uncertainties associated with aerosol representation and enhance the fidelity of the aerosol models. The goal of this research is to produce aerosol fields with reduced uncertainty by constraining model predictions with observations, using a technique known as data assimilation. The results from the aerosol assimilation are used to investigate aerosol sources, lifetime, and shortwave radiative forcing. Two new aerosol data assimilations are presented as part of this work with both assimilations making use of an Ensemble Kalman Filter (EnKF) and the National Center for Atmospheric Research's (NCAR) community atmosphere model (CAM) with 60 ensemble members. The first assimilation involves the joint adjustment of the amount of atmospheric aerosol and the relative amount of fine and coarse aerosol using observations of aerosol optical depth (AOD) and angstrom exponent from NASA's Moderate Resolution Imaging Spectroradiometer (MODIS). Both the amount and relative contribution of fine and coarse aerosol were identified as key parameters for determining aerosol radiative forcing and, therefore, accurately determining these parameters is desirable. The second assimilation presented as part of this work is similar to the first with the addition of a vertical redistribution of coarse aerosol using vertical extinction observations from NASA's Cloud-Aerosol LIDAR and Infrared Pathfinder Satellite Observations (CALIPSO) satellite. Studies have shown that the atmospheric lifetime of aerosol is tightly coupled to the vertical profile, therefore, it is expected that vertical adjustments will further reduce aerosol uncertainty, especially in coarse aerosol. Similar to aerosol amount and size, lifetime is important for properly quantifying radiative forcing as it determines the time an aerosol has to impact the climate and influences the horizontal distribution of aerosol that is highly heterogenous in space and time. The two presented assimilations are run for the year 2007 and results are compared against a control run simulation as well observations of AOD, angstrom exponent, and fine aerosol contributions from MODIS and NASA's Aerosol Robotic Network (AERONET). Through the comparison, it is demonstrated that the presented assimilations are able to reduce the model bias with an increase in the predicted aerosol optical depth. The globally averaged control run AOD prediction for 2007 is 0.086(± 0.06). The globally average AOD predictions for the amount and size assimilation and vertical assimilation are 0.115(± 0.05), 0.140(± 0.05), respectively. This is compared to globally averaged MODIS observations of 0.161(± 0.09). Over-ocean averaged angstrom exponent predictions from the control run are 0.65(± 0.35) while the size and amount and vertical assimilation predictions are 0.68 (± 0.15) and 0.66 (± 0.15), respectively. This is compared to globally averaged MODIS observations of 0.65(± 0.30). While it is difficult to determine improvements in angstrom exponent predictions based on the global average, clear reductions in regional biases were observed. Aerosol predictions are also compared to ground-based AERONET observations by site category, including desert dust, biomass burning, rural, industrial pollution, polluted marine, and dirty pollution. While the rural sites have statistically similar averaged AOD values across simulations, improvements are found for the other site categories in the assimilation runs with higher average AOD values and greater temporal variability. In addition to AOD comparison, the predicted amount of AOD due to fine aerosol is compared to AERONET observations by site category. The greatest reduction in bias is observed for polluted marine sites with the assimilation runs predicting a smaller fine aerosol contribution than the control simulation. Size-related observations are concentrated over ocean regions, therefore, the greatest impact of the assimilation with respect to size is expected for marine sites. Additionally, the positive bias in fine aerosol contribution predicted at dusty sites is reduced the most in the vertical assimilation with dust being mostly coarse in size. The adjustments to the vertical profile of coarse aerosol in the vertical assimilation further reduce bias for coarse dominated sites. The results of the assimilation are used to quantify the contribution of anthropogenic aerosol to AOD. Globally averaged, the anthropogenic contribution to AOD is 38.8 percent for the control simulation, 47.6 percent for the amount and size assimilation and 49.5 percent from the vertical assimilation. These results are comparable to previously published anthropogenic AOD percentages which range from 41 to 72 percent (IPCC 2007). Additionally, aerosol loss processes and lifetime are analyzed. The dominant loss processes are condensational growth for nucleation mode aerosol (fine, 1 & mum). The longest aerosol lifetimes are found in the vertical assimilation with most aerosol species showing better comparison to reported AEROCOM lifetimes, except for sulfate. In particular, the lifetimes of coarse mode dust and sea salt increased in the vertical adjustment assimilation, reducing the negative aerosol optical depth bias, especially in dusty regions. The predicted sulfate lifetime is double the reported AEROCOM value and may be the cause of some positive AOD bias regions in the Northern hemisphere predicted in the model runs. The solar direct radiative forcing (DRE) is calculated using the predicted aerosol fields with the DRE including the effects of both anthropogenic and natural aerosol. Uncertainties in DRE for the assimilation runs are determined using the 60 member ensemble spread. Globally averaged DRE values are -1.9 W/m2, -5.2(± 0.51) W/m2, and -7.2(± 0.94) W/m2, for the control, amount and size and vertical assimilation, respectively. The predicted DRE from the amount and size assimilation compares the best to previously published estimates. Additionally, the calculated anthropogenic contribution to AOD is used in conjunction with the DRE estimates to calculate shortwave anthropogenic direct radiative forcing estimates with predicted values of -0.77, -2.3(± 0.64) and -3.2(± 0.7) W/m2 for the control, amount and size assimilation and vertical assimilation, respectively.