Download or read book Preliminary Investigation of the Role that DMS Dimethyl Sulfide and Cloud Cycles Play in the Formation of the Aerosol Size Distribution written by W. A. Hoppel and published by . This book was released on 1987 with total page 37 pages. Available in PDF, EPUB and Kindle. Book excerpt: A series of experiments designed to study the production of new particulate matter by photolysis of dimethyl sulfide (DMS) and the effect that nonprecipitating clouds, have on the aerosol size distributions were carried out in Calspan Corporation's 600 cum environmental chamber during January and February 1986. The results show that DMS, the most abundant natural source of sulfur, is photooxidized to some product of low volatility that can form new particles by homogeneous nucleation or condense on existing aerosols causing them to grow. To explain these observations, a theoretical study of the nucleation properties of methane sulfonic acid (MSA) was undertaken. The nucleation thresholds, calculated using thermodynamic data for MSA, show that at 70% RH, and MSA concentration of only 0.006 ppb will result in a supersaturated environment in which MSA will condense on preexisting particles larger than 0.02 micron radius. If the MSA concentrations increase to 30 ppb, then spontaneous formation of MSA solution droplets occurs by homogeneous binary nucleation. Simulations of the evolution of the size distribution observed for the DMS irradiation experiments with a dynamic aerosol model that includes the effects of coagulation, growth by condensation, and deposition to the walls of the chamber, yield results that are in excellent agreement with the observed evolution.
Download or read book Energy Research Abstracts written by and published by . This book was released on 1988 with total page 1684 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Acid Precipitation written by and published by . This book was released on 1988 with total page 594 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Technical Reports Awareness Circular TRAC written by and published by . This book was released on 1987-12 with total page 306 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Government Reports Annual Index written by and published by . This book was released on 1988 with total page 1058 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sections 1-2. Keyword Index.--Section 3. Personal author index.--Section 4. Corporate author index.-- Section 5. Contract/grant number index, NTIS order/report number index 1-E.--Section 6. NTIS order/report number index F-Z.
Download or read book Government Reports Announcements Index written by and published by . This book was released on 1988 with total page 1142 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Sea Salt Aerosol Production written by Ernie R. Lewis and published by American Geophysical Union. This book was released on 2004-01-09 with total page 423 pages. Available in PDF, EPUB and Kindle. Book excerpt: Published by the American Geophysical Union as part of the Geophysical Monograph Series, Volume 152. Sea salt aerosol (SSA) exerts a major influence over a broad reach of geophysics. It is important to the physics and chemistry of the marine atmosphere and to marine geochemistry and biogeochemistry generally. It affects visibility, remote sensing, atmospheric chemistry, and air quality. Sea salt aerosol particles interact with other atmospheric gaseous and aerosol constituents by acting as sinks for condensable gases and suppressing new particle formation, thus influencing the size distribution of these other aerosols and more broadly influencing the geochemical cycles of substances with which they interact. As the key aerosol constituent over much of Earth's surface at present, and all the more so in pre-industrial times, SSA is central to description of Earth's aerosol burden.
Download or read book Direct Measurements of Marine Aerosols to Examine the Influence of Biological Activity Anthropogenic Emissions and Secondary Processing on Particle Chemistry written by Cassandra Jayne Gaston and published by . This book was released on 2012 with total page 294 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aerosols influence global climate directly by scattering and absorbing incoming solar radiation and indirectly by initiating cloud droplet and ice crystal formation; both particle size and chemical composition play a role in these impacts. Particle size and composition constantly evolve due to atmospheric processing. The physicochemical properties of marine aerosols, including sea spray and anthropogenic emissions, are of particular interest since oceans cover over 70% of the Earth's surface. This dissertation aims to probe the role of oceanic biological activity, anthropogenic emissions, and subsequent atmospheric processing on marine particle chemistry by measuring the size-resolved chemistry of individual ambient marine aerosols and laboratory-generated particles using aerosol time-of-flight mass spectrometry (ATOFMS). The impact of biological activity on the mixing-state of sea spray particles was examined by adding biologically-derived organic material and/or phytoplankton cells to seawater then generating particles through bubble bursting. Unique particles characterized by organics, Mg2 and/or Ca2 were detected during these experiments as well as in the ambient atmosphere during periods of elevated biological activity. Additionally, elemental sulfur ions were also detected in ambient marine particles in regions of elevated biological activity at night. These particles were successfully reproduced from bubble bursting experiments suggesting that these particles are directly ejected from the ocean. In addition to sea spray aerosol, the particle chemistry of marine aerosols from anthropogenic sources was also examined during shipboard measurements made during CalNex along the California coast. Soot was dominant in Southern California while organics characterized the particle chemistry in the Sacramento area highlighting regional differences in anthropogenic emissions in California. Further, measurements made at the Port of Los Angeles and those made on the Scripps Pier showed a decline in emissions from ships combusting residual fuel compared to earlier measurements; these results are in compliance with recent regulations requiring ships to combust low sulfur fuel when approaching the California coast. Finally, during the Study of Organic Aerosols in Riverside, CA (SOAR), the dimethyl sulfide (DMS) oxidation product methanesulfonic acid (MSA) was detected in anthropogenic particle types, and was elevated in vanadium-containing emissions characteristic of residual fuel combustion suggesting that anthropogenic particles can enhance the atmospheric processing of marine biogenic emissions.
Download or read book Biological and Environmental Chemistry of DMSP and Related Sulfonium Compounds written by M.D. Keller and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 422 pages. Available in PDF, EPUB and Kindle. Book excerpt: ''An essential book for people working in the area of sulfur compounds in the environment and should be in all institutional libraries....Well indexed, well presented.'' --- SGM Quarterly, November 1997 ''Extremely useful and well-produced symposium volume that should be of interest to many environmental scientists, microbial and plant physiologists, and aquatic ecologists.'' The Quarterly Review of Biology, June 1998
Download or read book Government Reports Annual Index Keyword A L written by and published by . This book was released on 1988 with total page 1600 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 An Investigation of Mechanisms of Aerosol induced Invigoration in Deep Convection written by Amy Yu and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Clouds are an important component of Earth's climate and hydrological system. Aerosols play a critical role in cloud formation by acting as cloud condensation nuclei. Altering aerosol properties would arguably have impacts on the microphysics and dynamics of the cloud formation process. In particular, deep convective clouds (DCCs) are comprised of three major regions-warm, mixed-phase, and cold. The complex structure of DCCs reflects on the behavior of DCCs in response to changes in aerosol loading. Studies done by others have proposed various hypotheses, some of which conflict with one another, on the microphysical and dynamic effects aerosols have on DCCs. The lack of consensus illustrates a need to collectively assess these hypotheses. In this study, a deep convective storm is simulated using RAMS to explore the microphysics and dynamics of DCCs under different environmental conditions and with varying aerosol concentrations. Consistent with many studies, analysis of simulations in this study generally show an increase in average updraft speeds in response to aerosol loading. Specifically, this study investigates three hypotheses found in literature: freeze-based aerosol invigoration, condensate loading, and condensation-based aerosol invigoration. Through a series of mechanism denial tests, results show supersaturation to be most strongly tied to the aerosol-induced invigoration process. This study also addresses the possibility of impacts from smaller sized aerosol particles and secondary activation on deep convection. The influences of secondary activation on updraft speeds remain inconclusive as results appear to be dependent on environmental conditions. Meanwhile, the impacts of Aitken mode aerosols are found to be considerably smaller on convective invigoration compared to accumulation mode aerosols. From a broader perspective, this study calls for more consideration to details when parameterizing convective schemes.
Download or read book Ocean Atmosphere Interactions of Gases and Particles written by Peter S. Liss and published by Springer. This book was released on 2013-12-18 with total page 366 pages. Available in PDF, EPUB and Kindle. Book excerpt: The oceans and atmosphere interact through various processes, including the transfer of momentum, heat, gases and particles. In this book leading international experts come together to provide a state-of-the-art account of these exchanges and their role in the Earth-system, with particular focus on gases and particles. Chapters in the book cover: i) the ocean-atmosphere exchange of short-lived trace gases; ii) mechanisms and models of interfacial exchange (including transfer velocity parameterisations); iii) ocean-atmosphere exchange of the greenhouse gases carbon dioxide, methane and nitrous oxide; iv) ocean atmosphere exchange of particles and v) current and future data collection and synthesis efforts. The scope of the book extends to the biogeochemical responses to emitted / deposited material and interactions and feedbacks in the wider Earth-system context. This work constitutes a highly detailed synthesis and reference; of interest to higher-level university students (Masters, PhD) and researchers in ocean-atmosphere interactions and related fields (Earth-system science, marine / atmospheric biogeochemistry / climate). Production of this book was supported and funded by the EU COST Action 735 and coordinated by the International SOLAS (Surface Ocean- Lower Atmosphere Study) project office.
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 The NASA AMES Research Center Stratospheric Aerosol Model 1 Physical Processes and Computational Analogs written by and published by . This book was released on 1979 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Study of the Aerosol Formation from the Mixture of Isoprene and Dimethyl Sulfide in the Presence of NOx written by Tianyi Chen and published by . This book was released on 2012 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt: The most recently reported reactions with their rate constants have been included. The model included in this study predicted that concentrations of both MSA and H2SO4 would significantly increase due to heterogeneous chemistry, and this was well substantiated with experimental data. To confirm the DMS effect on SOAformation in the ambient air, the effect of MSA on increasing the SOA mass and the relative contribution of SO2 and DMS to sulfate were evaluated through ambient aerosol samples. Our results suggest that DMS is a significant source of acidic aerosol (H2SO4 and MSA) in the coastal area and in the land surrounded by fresh water wetland or salt marsh.
Download or read book The Relationship Between Aerosol and Drop Size Distributions in the Marine Atmosphere written by and published by . This book was released on 1990 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: The characteristics of droplet size distributions near cloud base are initially determined by the aerosol particles that act as cloud condensation nuclei (CCN). Through physical and chemical processes that determine the fraction of aerosol particles that act as CCN, these particles profoundly affect the microphysical structure of clouds and their tendency to form precipitation. This paper provides a parametric study of the condensational growth on aerosol distributions from typical measurements in the marine atmosphere, and answers the following questions with respect to this process. (1) How does the condensationally produced droplet spectrum vary with the initial aerosol size distribution, aerosol number loading, and the updraft velocity (2) What is the fraction of aerosol particles that act as CCN This information can be applied to the future study to parameterize the number concentration of cloud droplets in climate models. (3) How do the optical properties of the cloud change as a result of the production of different droplet size distributions 8 figs.
