Download or read book Mechanisms of Formation of Secondary Organic Aerosols and Implications for Global Radiative Forcing written by and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Organic material constitutes about 50% of global atmospheric aerosol mass, and the dominant source of organic aerosol is the oxidation of volatile hydrocarbons, to produce secondary organic aerosol (SOA). Understanding the formation of SOA is crucial to predicting present and future climate effects of atmospheric aerosols. The goal of this program is to significantly increase our understanding of secondary organic aerosol (SOA) formation in the atmosphere. Ambient measurements indicate that the amount of SOA in the atmosphere exceeds that predicted in current models based on existing laboratory chamber data. This would suggest that either the SOA yields measured in laboratory chambers are understated or that all major organic precursors have not been identified. In this research program we are systematically exploring these possibilities.
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 Atmospheric Chemistry and Physics written by John H. Seinfeld and published by John Wiley & Sons. This book was released on 2016-03-29 with total page 1152 pages. Available in PDF, EPUB and Kindle. Book excerpt: Expanded and updated with new findings and new features New chapter on Global Climate providing a self-contained treatment of climate forcing, feedbacks, and climate sensitivity New chapter on Atmospheric Organic Aerosols and new treatment of the statistical method of Positive Matrix Factorization Updated treatments of physical meteorology, atmospheric nucleation, aerosol-cloud relationships, chemistry of biogenic hydrocarbons Each topic developed from the fundamental science to the point of application to real-world problems New problems at an introductory level to aid in classroom teaching
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 Secondary Organic Aerosol SOA Formation from Aqueous OH Radical Oxidation of Dicarbonyl Compounds in the Atmosphere written by Yi Tan and published by . This book was released on 2010 with total page 219 pages. Available in PDF, EPUB and Kindle. Book excerpt: Secondary organic aerosols (SOA) affect visibility, health and global climate. Current chemical transport models cannot represent SOA in the free troposphere. Fog/cloud processing, which is the dominant source of atmospheric sulfate, has been recognized as a missing source of SOA globally. Aqueous photooxidation of water-soluble products (e.g., glyoxal and methylglyoxal) of gas-phase photochemistry yields low-volatility compounds including oxalic acid. When this chemistry takes place in clouds and fogs followed by droplet evaporation (or if this chemistry occurs in aerosol water) then products remain in part in the particle phase, forming SOA. However, current aqueous SOA formation mechanism has not shown how the starting concentrations of precursors and presence of acidic sulfate affect product formation. Aqueous phase photochemical batch reactions were conducted with glyoxal and methylglyoxal at cloud relevant concentrations, using hydrogen peroxide photolysis as the hydroxyl radical (OH) source. Experiments were repeated at higher concentrations and with/without sulfuric acid. Precursors and products were investigated using ion chromatography (IC), electrospray ionization mass spectrometry (ESI-MS), and IC-ESI-MS. Products included carboxylic acids and higher molecular weight compounds, which are major constituents of aerosols. Sulfuric acid shows little effect on product formation. Dilute aqueous chemistry models successfully reproduced product formation for glyoxal and methylglyoxal at cloud relevant conditions, but measurements deviated from predictions from predictions at elevated concentrations. Higher molecular weight products become increasingly important as precursor concentration increases. Aqueous radical-radical reactions provide explanations for observed higher molecular weight products. Additionally, acetic acid is identified as an SOA precursor for the first time. This work provides an improved understanding of aqueous phase dicarbonyl oxidation mechanism and the overall significance of aqueous SOA formation. Kinetic data are made available to regional and global atmospheric models, and the mechanism described in this work will help people to mitigate adverse aerosol effects.
Download or read book Atmospheric Aerosols written by Claudio Tomasi and published by John Wiley & Sons. This book was released on 2017-03-20 with total page 706 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ein Blick auf die morphologischen, physikalischen und chemischen Eigenschaften von Aerosolen aus den unterschiedlichsten natürlichen und anthropogenen Quellen trägt zum besseren Verständnis der Rolle bei, die Aerosolpartikel bei der Streuung und Absorption kurz- und langwelliger Strahlung spielen. Dieses Fachbuch bietet Informationen, die sonst schwer zu finden sind, und vermittelt ausführlich die Kenntnisse, die erforderlich sind, um die mikrophysikalischen, chemischen und Strahlungsparameter zu charakterisieren, die bei der Wechselwirkung von Sonnen- und Erdstrahlen so überaus wichtig sind. Besonderes Augenmerk liegt auf den indirekten Auswirkungen von Aerosolen auf das Klima im Rahmen des komplexen Systems aus Aerosolen, Wolken und der Atmosphäre. Auch geht es vorrangig um die Wirkungen natürlicher und anthropogener Aerosole auf die Luftqualität und die Umwelt, auf die menschliche Gesundheit und unser kulturelles Erbe. Mit einem durchgängig lösungsorientierten Ansatz werden nicht nur die Probleme und Gefahren dieser Aerosole behandelt, sondern auch praktikable Lösungswege aufgezeigt.
Download or read book Aerosols in Atmospheric Chemistry written by Yue Zhang and published by American Chemical Society. This book was released on 2022-04-01 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt: The uncertainties in the aerosol effects on radiative forcing limit our knowledge of climate change, presenting us with an important research challenge. Aerosols in Atmospheric Chemistry introduces basic concepts about the characterization, formation, and impacts of ambient aerosol particles as an introduction to graduate students new to the field. Each chapter also provides an up-to-date synopsis of the latest knowledge of aerosol particles in atmospheric chemistry.
Download or read book Observing and Modeling Earth s Energy Flows written by Lennart Bengtsson and published by Springer. This book was released on 2012-09-07 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a comprehensive presentation of Earth’s energy flows and their consequences for the climate. The Earth’s climate as well as planetary climates in general, are broadly controlled by three fundamental parameters: the solar irradiance, the planetary albedo and the planetary emissivity. Space measurements indicate that these three quantities are remarkably stable. A minor decrease in planetary emissivity is consistent with theoretical calculations. This is due to the ongoing increase of atmospheric greenhouse gases making the atmosphere more opaque to long wave terrestrial radiation. As a consequence radiation processes are slightly out of balance as less heat is leaving the Earth in the form of thermal radiation than the incoming amount of heat from the sun. Present space-based systems cannot yet satisfactorily measure this imbalance, but the effect can be inferred from the measurements of the increase of heat in the oceans. Minor amounts of heat are also used to melt ice and to warm the atmosphere and the surface of the Earth. The book brings to fore the complexity of feedback processes of the Earth’s climate system and in particular the way clouds and aerosols affect the energy balance both directly and indirectly through feed-back loops driven by the dynamics of atmospheric, ocean and land surface processes. The book highlights recent scientific progress as well as remaining challenges. Previously published in Surveys in Geophysics, Volume 33, Nos. 3-4, 2012
Download or read book Secondary Organic Aerosol Formation Mechanisms and Source Contributions in Europe written by Ulrike Dusek and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Environmental Simulation Chambers Application to Atmospheric Chemical Processes written by Ian Barnes and published by Springer Science & Business Media. This book was released on 2006-01-13 with total page 492 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book gives in the first instance descriptions of different types of so-called environment chambers or photoreactors used mainly for the simulation and/or investigation of important chemical processes occurring in the atmosphere. The types of reactor described include outdoor and indoor chambers, temperature regulated chambers and glass and Teflon foil chambers The practical use of chambers is demonstrated in contributions by leading scientists in the field of atmospheric chemistry using, in many cases, current results. The types of atmospherically relevant investigations described include the measurement of reactivities, the measurement of radicals, the measurement of photolysis frequencies and products, kinetic and product studies on the oxidation of different types of hydrocarbons by important oxidant species (OH, N03, 03), formation of secondary organic aerosol from hydrocarbon oxidation etc. A special section includes contributions from eastern European countries which highlight some of the environmental research being performed in these countries. An abridged version of a specially commissioned review by the JRC Ispra on the status of environmental research in eastern European countries is also included in this section.
Download or read book Introduction to Atmospheric Chemistry written by Daniel J. Jacob and published by Princeton University Press. This book was released on 1999 with total page 280 pages. Available in PDF, EPUB and Kindle. Book excerpt: Atmospheric chemistry is one of the fastest growing fields in the earth sciences. Until now, however, there has been no book designed to help students capture the essence of the subject in a brief course of study. Daniel Jacob, a leading researcher and teacher in the field, addresses that problem by presenting the first textbook on atmospheric chemistry for a one-semester course. Based on the approach he developed in his class at Harvard, Jacob introduces students in clear and concise chapters to the fundamentals as well as the latest ideas and findings in the field. Jacob's aim is to show students how to use basic principles of physics and chemistry to describe a complex system such as the atmosphere. He also seeks to give students an overview of the current state of research and the work that led to this point. Jacob begins with atmospheric structure, design of simple models, atmospheric transport, and the continuity equation, and continues with geochemical cycles, the greenhouse effect, aerosols, stratospheric ozone, the oxidizing power of the atmosphere, smog, and acid rain. Each chapter concludes with a problem set based on recent scientific literature. This is a novel approach to problem-set writing, and one that successfully introduces students to the prevailing issues. This is a major contribution to a growing area of study and will be welcomed enthusiastically by students and teachers alike.
Download or read book Molecular Composition Volatility and Formation Mechanisms of Biogenic Secondary Organic Aerosol written by Emma Louise D'Ambro and published by . This book was released on 2018 with total page 129 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Formation Mechanisms of Secondary Organic Aerosols in Relation to Laser Printer Emissions written by Hao Wang and published by . This book was released on 2011 with total page 267 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Insights Into Predicting Secondary Organic Aerosol Formation from Anthropogenic Volatile Organic Compounds written by Lijie Li and published by . This book was released on 2016 with total page 274 pages. Available in PDF, EPUB and Kindle. Book excerpt: Understanding secondary organic aerosol (SOA) formation is of critical importance to public health and global climate. SOA formation from anthropogenic volatile organic compounds (VOCs) is influenced by NO, precursor molecular structure, oxidation conditions and other factors. This dissertation explores the impact of NO effect and molecular structure for two categories of VOCs at urban atmosphere relevant conditions by utilizing the state of art 90 m3 UCR/CE-CERT chamber facilities.
Download or read book Understanding the Global Effect of Secondary Organic Aerosol on Size Distributions in Past and Present Climates written by Stephen D'Andrea and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
