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 Energy Research Abstracts written by and published by . This book was released on 1994 with total page 806 pages. Available in PDF, EPUB and Kindle. Book excerpt: Semiannual, with semiannual and annual indexes. References to all scientific and technical literature coming from DOE, its laboratories, energy centers, and contractors. Includes all works deriving from DOE, other related government-sponsored information, and foreign nonnuclear information. Arranged under 39 categories, e.g., Biomedical sciences, basic studies; Biomedical sciences, applied studies; Health and safety; and Fusion energy. Entry gives bibliographical information and abstract. Corporate, author, subject, report number indexes.
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 Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 652 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.
Download or read book Acid Precipitation written by and published by . This book was released on 1994 with total page 1044 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 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 Connecting Chemistry and Climate Through Aerosol Particles Laboratory and Field Studies of Cloud Condensation Nuclei written by Douglas Bradford Collins and published by . This book was released on 2014 with total page 255 pages. Available in PDF, EPUB and Kindle. Book excerpt: The influence of aerosol particles on the Earth's climate is a major driver of scientific uncertainty in assessing future conditions. The importance of aerosols in their role as cloud condensation nuclei (CCN) and ice nuclei (IN), known as the Aerosol Indirect Effect, is most poorly understood. The number concentration of CCN available to nucleate droplets can have important influences on cloud albedo, lifetime, and propensity to form precipitation. Natural sources are of particular importance, since the absolute influence of aerosols on cloud properties is highly sensitive to background concentrations of CCN before anthropogenic emissions. Chemical studies of sea spray aerosol (SSA) particles, the second most abundant type of natural aerosol globally, were conducted to better understand the influence of marine organic matter on CCN activity. While direct chemical measurements of aerosol particles with diameter (d) > 500 nm indicated that the production mechanism of SSA controls particle composition, especially with respect to the amount of organic matter transferred across the air-sea interface. CCN activity studies, on the other hand, showed a weak dependence on seawater organic matter concentration. The extent to which organic matter and sea salt were externally mixed for particles with d
Download or read book Government Reports Annual Index written by and published by . This book was released on 1994 with total page 1144 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Chemical Composition and Cloud Nucleation Ability of Marine Aerosol written by Chunhua Deng and published by . This book was released on 2014 with total page 179 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study is focused on the chemical composition and cloud nucleation ability of marine aerosol based on two cruise researches over Pacific Ocean and North Atlantic Ocean respectively. Implications of CLAW hypothesis and the factors influencing its validity are analyzed for the contemporary era with ever-increasing pollution. The pacific cruise started from Punta Arenas, Chile and ended in Seattle, WA during March-April of 2010. Raman microspectroscopy (RMS) was employed to identify the chemical composition and mixing conditions of single particles collected. By analyzing multiple particles in a collected ensemble, the degree of external/internal mixing of particles was also determined. Atmospheric aerosol concentration, cloud condensation nuclei (CCN) concentration, and chlorophyll a concentration in the underlying water (a metric for phytoplankton biomass in the ocean), were also measured. Our results indicate that long chain organic molecules were prevalent in the marine aerosol samples throughout the cruise. Long chain organic compounds tended to stay mixed with other organic and inorganic components. The influence of marine organic aerosols on cloud nucleation ability is analyzed. The North Atlantic cruise started from Woods Hole, MA and returned back to the same location during June-July 2011. The cruise passed through a wide range of conditions, including areas of high phytoplankton biomasses and extremely high DMS levels (over 1800 pptv). Aerosol concentration, cloud condensation nuclei (CCN) concentration, particle size distribution, as well as surface seawater and atmospheric DMS concentrations were performed simultaneously during the cruise. HYSPLIT back trajectories were used to classify air mass origins. Even though continental sources increased the total aerosol population, it depressed the effective CCN concentrations possibly due to the competition in particle growth. Continuous high CCN and elevated DMS concentrations over the open ocean occur concurrently, which can be explained by enhanced nucleation and condensational growth of aerosols in marine boundary layer (MBL) resulting from the DMS oxidation or primary aerosols from the sea surface. Our data also indicated that uncertainties remain in sea spray aerosol production flux function, especially for particles with dry diameter smaller than 200 nm. The electronic version of this dissertation is accessible from http://hdl.handle.net/1969.1/151824
Download or read book Clouds in the Perturbed Climate System written by Jost Heintzenberg and published by Strungmann Forum Reports. This book was released on 2009 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: More than half the globe is covered by visible clouds.
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 Government Reports Announcements Index written by and published by . This book was released on 1994 with total page 1142 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Oceanic Whitecaps written by E.C. Monahan and published by Springer Science & Business Media. This book was released on 1986-04-30 with total page 316 pages. Available in PDF, EPUB and Kindle. Book excerpt: While various volumes havepreviously been de bable, answer to this question lies in the obser vation that while whitecaps are some of the voted to such topics as droplets and bubbles, it is our conceit that this is the first volume dedi most apparent features associated with high sea cated to the description of the phenomenon states, they have also pro\'ed to be someofthe of oceanic whitecapping, and to a considera most difficult objects to measure and describe tion of the role these whitecapsplay in satellite quantitatively, and while scientists as a group marine remote sensing, in sea-salt aerosol gene may like to tackle difficult problems, we ration, and in a broad range ofother sea surface should not be accused ofundue modesty when processes. This observation, reOecting in part we observe that as a group we also have a finite the relatively modest attention paid until re tolerance for frustration and ahuman,perhaps cently by the scientific community to white aesthetic, prejudice in favour ofnatural pheno caps, is noteworthy when one considers that mena that are amcnable to detailed description. collectively whitecaps are to thegeneral public It is appropriate to note that Professor Wood one of the most striking features of the sea cock, to whom this volume is dedicated, ap scape.
Download or read book Linkage of Anthropogenic Aerosol to Clouds and Climate Final Report written by and published by . This book was released on 1997 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt: Work performed between July 1991 and June 1994 is very briefly summarized in this report. The work done concerns differences between clouds and the aerosol particles, or cloud condensation nuclei (CCN), upon which the cloud droplets condense. In particular, the substantial contribution of anthropogenic sources to CCNs and their effects on clouds were examined. Ship board measurements of CCN concentrations in clouds were taken in July 1991. In June 1992, aircraft measurements and analyses of CCN concentrations showed substantial influences of anthropogenic aerosol on clouds through long-range transport of polluted air. A June 1994 study indicated that CCN produced by ships caused ship trail clouds even in moderately polluted clouds.
Download or read book Aerosol Pollution Impact on Precipitation written by Zev Levin and published by Springer Science & Business Media. This book was released on 2008-09-30 with total page 399 pages. Available in PDF, EPUB and Kindle. Book excerpt: Life on Earth is critically dependent upon the continuous cycling of water between oceans, continents and the atmosphere. Precipitation (including rain, snow, and hail) is the primary mechanism for transporting water from the atmosphere back to the Earth’s surface. It is also the key physical process that links aspects of climate, weather, and the global hydrological cycle. Changes in precipitation regimes and the frequency of extreme weather events, such as floods, droughts, severe ice/snow storms, monsoon fluctuations and hurricanes are of great potential importance to life on the planet. One of the factors that could contribute to precipitation modification is aerosol pollution from various sources such as urban air pollution and biomass burning. Natural and anthropogenic changes in atmospheric aerosols might have important implications for precipitation by influencing the hydrological cycle, which in turn could feed back to climate changes. From an Earth Science perspective, a key question is how changes expected in climate will translate into changes in the hydrological cycle, and what trends may be expected in the future. We require a much better understanding and hence predictive capability of the moisture and energy storages and exchanges among the Earth’s atmosphere, oceans, continents and biological systems. This book is a review of our knowledge of the relationship between aerosols and precipitation reaching the Earth's surface and it includes a list of recommendations that could help to advance our knowledge in this area.
