Download or read book LABORATORY STUDIES OF THE INTERSTITIAL AEROSOL REMOVAL MECHANISMS IN A CLOUD CHAMBER written by and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract : Aerosol particles and cloud droplets are not static entities but are continuously interacting with their chemical environment and therefore changing in their properties [1]. Also, clouds are ubiquitously turbulent, so water vapor or other trace gases fluctuate in space and time. Aerosol properties such as number concentration, chemical composition and size influence many cloud properties including the clouds' probability for precipitation and hence their lifetime. Also, an increase in the number of aerosol particles can lead to an increase in cloud droplet number and decrease the effective droplet radius, which results in an increase in a cloud's albedo for a constant liquid water path. In response, clouds serve as a dominant removal mechanism for intermediate sized aerosol particles while other sizes are removed via other loss processes such as settling and diffusion. This feedback between aerosol and cloud is the process of cloud cleansing through which cloudy, polluted air from a continent is slowly transformed into cloudy, clean air of a maritime environment. A facility, the Pi Chamber, so called because of its working volume of 3.14 m3 with the cylindrical insert in place is developed at Michigan Tech to study the interaction of gases, aerosols and clouds in a turbulent environment. Within the Pi Chamber, a turbulent environment is created via a temperature difference between the top and bottom surfaces, inducing turbulent Rayleigh B℗þenard convection. Cloud formation is xvii initiated by injecting NaCl aerosol from a constant output atomizer into the chamber. In our experiments, we employ different temperature gradients (hot on the bottom and cold on top) to drive turbulent convection. Once the cloud properties reach steady state,the aerosol source is turned off to initiate the cloud cleansing process. Size distributions of the interstitial aerosol are acquired continuously using a Scanning Mobility Particle Sizer (SMPS). Measurement of the distribution of interstitial aerosol as a function of time is used to derive characteristic decay times as a function of size. Our data suggest that for aerosol particles with dry diameters between about 40 nm and 100 nm, the principal removal mechanism is activation which proceeds in a two-stage process; ie decay of interstitial aerosol concentration occurs slowly at first, then more rapidly. Smaller particles of diameters about 10 nm to 20 nm are not activated but removed through convective diffusion. The cloud cleansing process thus demonstrates a simplified version of evolution of polluted clouds to a maritime state.
Download or read book A State Of the Art Experimental Laboratory for Cloud and Cloud Aerosol Interaction Research written by Nasa Technical Reports Server (Ntrs) and published by BiblioGov. This book was released on 2013-07 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt: The state of the art for predicting climate changes due to increasing greenhouse gasses in the atmosphere with high accuracy is problematic. Confidence intervals on current long-term predictions (on the order of 100 years) are so large that the ability to make informed decisions with regard to optimum strategies for mitigating both the causes of climate change and its effects is in doubt. There is ample evidence in the literature that large sources of uncertainty in current climate models are various aerosol effects. One approach to furthering discovery as well as modeling, and verification and validation (V&V) for cloud-aerosol interactions is use of a large "cloud chamber" in a complimentary role to in-situ and remote sensing measurement approaches. Reproducing all of the complex interactions is not feasible, but it is suggested that the physics of certain key processes can be established in a laboratory setting so that relevant fluid-dynamic and cloud-aerosol phenomena can be experimentally simulated and studied in a controlled environment. This report presents a high-level argument for significantly improved laboratory capability, and is meant to serve as a starting point for stimulating discussion within the climate science and other interested communities.
Download or read book A Cloud Chamber Study of the Effect Which Nonprecipitating Clouds Have on the Aerosol Size Distribution written by and published by . This book was released on 1992 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt: When an air parcel in the atmosphere passes through a nonprecipitating cloud cycle, a subset of the aerosol population called cloud condensation nuclei (CCN) is activated and forms cloud droplets. During the cloud phase, trace gases, such as SO2, are dissolved into the droplets and undergo aqueous-phase chemical reactions, forming low-volatility products, such as sulfates, which remain as residue when the cloud droplets evaporate. The resulting increase in residual mass can have a dramatic effect on the aerosol size distribution, causing the CCN to grow relative to the smaller particles (interstitial aerosol) which were not activated in the cloud. This process was graphically demonstrated in a series of experiments carried out in the Calspan 600 m3 environmental chamber, under conditions where the precloud reactants could be carefully controlled. Size distributions taken before and after a cloud cycle showed significant conversion of SO2 to H2SO4 and a dramatic change in the aerosol size distribution. Subsequent cloud cycles (with the same expansion rate and trace gas concentrations) exhibited very small mass conversion rates. The decreased conversion rate is explained by the increased acidity of the cloud droplet due to the increased mass of the CCN. The terminal size of the resulting CCN was on the order of one-fiftieth the size of the cloud droplets. The pH of a droplet formed on a sulfuric acid aerosol particle one-fiftieth its size is about 5. Atmospheric aerosols, Atmospheric chemistry.
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 Program Program Operation Plan written by and published by . This book was released on 1993 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Short Course in Cloud Physics written by M.K. Yau and published by Elsevier. This book was released on 1996-05-15 with total page 308 pages. Available in PDF, EPUB and Kindle. Book excerpt: Covers essential parts of cloud and precipitation physics and has been extensively rewritten with over 60 new illustrations and many new and up to date references. Many current topics are covered such as mesoscale meteorology, radar cloud studies and numerical cloud modelling, and topics from the second edition, such as severe storms, precipitation processes and large scale aspects of cloud physics, have been revised. Problems are included as examples and to supplement the text.
Download or read book Aerosol Science written by Ian Colbeck and published by John Wiley & Sons. This book was released on 2014-02-03 with total page 522 pages. Available in PDF, EPUB and Kindle. Book excerpt: AEROSOL SCIENCE TECHNOLOGY AND APPLICATIONS Aerosols influence many areas of our daily life. They are at the core of environmental problems such as global warming, photochemical smog and poor air quality. They can also have diverse effects on human health, where exposure occurs in both outdoor and indoor environments. However, aerosols can have beneficial effects too; the delivery of drugs to the lungs, the delivery of fuels for combustion and the production of nanomaterials all rely on aerosols. Advances in particle measurement technologies have made it possible to take advantage of rapid changes in both particle size and concentration. Likewise, aerosols can now be produced in a controlled fashion. Reviewing many technological applications together with the current scientific status of aerosol modelling and measurements, this book includes: Satellite aerosol remote sensing The effects of aerosols on climate change Air pollution and health Pharmaceutical aerosols and pulmonary drug delivery Bioaerosols and hospital infections Particle emissions from vehicles The safety of emerging nanomaterials Radioactive aerosols: tracers of atmospheric processes With the importance of this topic brought to the public's attention after the eruption of the Icelandic volcano Eyjafjallajökull, this book provides a timely, concise and accessible overview of the many facets of aerosol science.
Download or read book Atmospheric Aerosols written by Olivier Boucher and published by Springer. This book was released on 2015-05-18 with total page 322 pages. Available in PDF, EPUB and Kindle. Book excerpt: This textbook aims to be a one stop shop for those interested in aerosols and their impact on the climate system. It starts with some fundamentals on atmospheric aerosols, atmospheric radiation and cloud physics, then goes into techniques used for in-situ and remote sensing measurements of aerosols, data assimilation, and discusses aerosol-radiation interactions, aerosol-cloud interactions and the multiple impacts of aerosols on the climate system. The book aims to engage those interested in aerosols and their impacts on the climate system: graduate and PhD students, but also post-doctorate fellows who are new to the field or would like to broaden their knowledge. The book includes exercises at the end of most chapters. Atmospheric aerosols are small (microscopic) particles in suspension in the atmosphere, which play multiple roles in the climate system. They interact with the energy budget through scattering and absorption of solar and terrestrial radiation. They also serve as cloud condensation and ice nuclei with impacts on the formation, evolution and properties of clouds. Finally aerosols also interact with some biogeochemical cycles. Anthropogenic emissions of aerosols are responsible for a cooling effect that has masked part of the warming due to the increased greenhouse effect since pre-industrial time. Natural aerosols also respond to climate changes as shown by observations of past climates and modelling of the future climate.
Download or read book How Tobacco Smoke Causes Disease written by United States. Public Health Service. Office of the Surgeon General and published by . This book was released on 2010 with total page 728 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report considers the biological and behavioral mechanisms that may underlie the pathogenicity of tobacco smoke. Many Surgeon General's reports have considered research findings on mechanisms in assessing the biological plausibility of associations observed in epidemiologic studies. Mechanisms of disease are important because they may provide plausibility, which is one of the guideline criteria for assessing evidence on causation. This report specifically reviews the evidence on the potential mechanisms by which smoking causes diseases and considers whether a mechanism is likely to be operative in the production of human disease by tobacco smoke. This evidence is relevant to understanding how smoking causes disease, to identifying those who may be particularly susceptible, and to assessing the potential risks of tobacco products.
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 Scientific and Technical Aerospace Reports written by and published by . This book was released on 1989 with total page 968 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.
Download or read book Microbiology of Aerosols written by Anne-Marie Delort and published by John Wiley & Sons. This book was released on 2017-09-11 with total page 349 pages. Available in PDF, EPUB and Kindle. Book excerpt: An introduction to the microbiology of bioaerosols and their impact on the world in which we live The microbiology of aerosols is an emerging field of research that lies at the interface of a variety of scientific and health-related disciplines. This eye-opening book synthesizes the current knowledge about microorganisms—bacteria, archaea, fungi, viruses—that are aloft in the atmosphere. The book is written collaboratively by an interdisciplinary and international panel of experts and carefully edited to provide a high-level overview of the emerging field of aerobiology. Four sections within Microbiology of Aerosols present the classical and online methods used for sampling and characterizing airborne microorganisms, their emission sources and short- to long-distance dispersal, their influence on atmospheric processes and clouds, and their consequences for human health and agro-ecosystems. Practical considerations are also discussed, including sampling techniques, an overview of the quantification and characterization of bioaerosols, transport of bioaerosols, and a summary of ongoing research opportunities in the field. Comprehensive in scope, the book: Explores this new field that is applicable to many disparate disciplines Covers the emission of bioaerosols to their deposit, covering both quantitative and qualitative aspects Provides insights into social and environmental effects of the presence of bioaerosols in the atmosphere Details the impact of bioaerosols on human health, animal and plant health, and on physical and chemical atmospheric processes Written by authors internationally recognized for their work on biological aerosols and originating from a variety of scientific fields collaborated on, Microbiology of Aerosols is an excellent resource for researchers and graduate or PhD students interested in atmospheric sciences or microbiology.
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.
Download or read book Microphysics of Clouds and Precipitation written by H.R. Pruppacher and published by Springer Science & Business Media. This book was released on 2010-06-25 with total page 975 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cloud physics has achieved such a voluminous literature over the past few decades that a significant quantitative study of the entire field would prove unwieldy. This book concentrates on one major aspect: cloud microphysics, which involves the processes that lead to the formation of individual cloud and precipitation particles. Common practice has shown that one may distinguish among the following addi tional major aspects: cloud dynamics, which is concerned with the physics respon sible for the macroscopic features of clouds; cloud electricity, which deals with the electrical structure of clouds and the electrification processes of cloud and precipi tation particles; and cloud optics and radar meteorology, which describe the effects of electromagnetic waves interacting with clouds and precipitation. Another field intimately related to cloud physics is atmospheric chemistry, which involves the chemical composition ofthe atmosphere and the life cycle and characteristics of its gaseous and particulate constituents. In view of the natural interdependence of the various aspects of cloud physics, the subject of microphysics cannot be discussed very meaningfully out of context. Therefore, we have found it necessary to touch briefly upon a few simple and basic concepts of cloud dynamics and thermodynamics, and to provide an account of the major characteristics of atmospheric aerosol particles. We have also included a separate chapter on some of the effects of electric fields and charges on the precipitation-forming processes.
Download or read book Precipitation Scavenging And Atmosphere Surface Exchange written by Stephen Schwartz and published by CRC Press. This book was released on 1992-06-01 with total page 616 pages. Available in PDF, EPUB and Kindle. Book excerpt: This three-volume set contains selected papers arising from a conference held in 1991 on precipitation and air pollution. The first volume addresses the precipitation scavenging process; the second deals with atmosphere-surface exchange processes; and the third covers air pollution and deposition.
Download or read book Multiphase Environmental Chemistry in the Atmosphere written by Sherri W. Hunt and published by ACS Symposium. This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book highlights new cross-disciplinary advances in aerosol chemistry that involve more than one phase, for example, unique chemical processes occurring on gas-solid and liquid-solid interfaces.
