Download or read book Studies of Ambient Organic and Inorganic Aerosol in Southern California written by Joseph James Ensberg and published by . This book was released on 2014 with total page 494 pages. Available in PDF, EPUB and Kindle. Book excerpt: The negative impacts of ambient aerosol particles, or particulate matter (PM), on human health and climate are well recognized. However, owing to the complexity of aerosol particle formation and chemical evolution, emissions control strategies remain difficult to develop in a cost effective manner. In this work, three studies are presented to address several key issues currently stymieing California's efforts to continue improving its air quality. Gas-phase organic mass (GPOM) and CO emission factors are used in conjunction with measured enhancements in oxygenated organic aerosol (OOA) relative to CO to quantify the significant lack of closure between expected and observed organic aerosol concentrations attributable to fossil-fuel emissions. Two possible conclusions emerge from the analysis to yield consistency with the ambient organic data: (1) vehicular emissions are not a dominant source of anthropogenic fossil SOA in the Los Angeles Basin, or (2) the ambient SOA mass yields used to determine the SOA formation potential of vehicular emissions are substantially higher than those derived from laboratory chamber studies. Additional laboratory chamber studies confirm that, owing to vapor-phase wall loss, the SOA mass yields currently used in virtually all 3D chemical transport models are biased low by as much as a factor of 4. Furthermore, predictions from the Statistical Oxidation Model suggest that this bias could be as high as a factor of 8 if the influence of the chamber walls could be removed entirely. Once vapor-phase wall loss has been accounted for in a new suite of laboratory chamber experiments, the SOA parameterizations within atmospheric chemical transport models should also be updated. To address the numerical challenges of implementing the next generation of SOA models in atmospheric chemical transport models, a novel mathematical framework, termed the Moment Method, is designed and presented. Assessment of the Moment Method strengths and weaknesses provide valuable insight that can guide future development of SOA modules for atmospheric CTMs. Finally, regional inorganic aerosol formation and evolution is investigated via detailed comparison of predictions from the Community Multiscale Air Quality (CMAQ version 4.7.1) model against a suite of airborne and ground-based meteorological measurements, gas- and aerosol-phase inorganic measurements, and black carbon (BC) measurements over Southern California during the CalNex field campaign in May/June 2010. Results suggests that continuing to target sulfur emissions with the hopes of reducing ambient PM concentrations may not the most effective strategy for Southern California. Instead, targeting dairy emissions is likely to be an effective strategy for substantially reducing ammonium nitrate concentrations in the eastern part of the Los Angeles Basin.

Download or read book Single Particle Characterization Source Apportionment and Aging Effects of Ambient Aerosols in Southern California written by Laura Grace Shields and published by ProQuest. This book was released on 2008 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt: Composed of a mixture of chemical species and phases and existing in a variety of shapes and sizes, atmospheric aerosols are complex and can have serious influence on human health, the environment, and climate. In order to better understand the impact of aerosols on local to global scales, detailed measurements on the physical and chemical properties of ambient particles are essential. In addition, knowing the origin or the source of the aerosols is important for policymakers to implement targeted regulations and effective control strategies to reduce air pollution in their region. One of the most ground breaking techniques in aerosol instrumentation is single particle mass spectrometry (SPMS), which can provide online chemical composition and size information on the individual particle level. The primary focus of this work is to further improve the ability of one specific SPMS technique, aerosol time-of-flight mass spectrometry (ATOFMS), for the use of identifying the specific origin of ambient aerosols, which is known as source apportionment. The ATOFMS source apportionment method utilizes a library of distinct source mass spectral signatures to match the chemical information of the single ambient particles. The unique signatures are obtained in controlled source characterization studies, such as with the exhaust emissions of heavy duty diesel vehicles (HDDV) operating on a dynamometer. The apportionment of ambient aerosols is complicated by the chemical and physical processes an individual particle can undergo as it spends time in the atmosphere, which is referred to as "aging" of the aerosol. Therefore, the performance of the source signature library technique was investigated on the ambient dataset of the highly aged environment of Riverside, California. Additionally, two specific subsets of the Riverside dataset (ultrafine particles and particles containing trace metals), which are known to cause adverse health effects, were probed in greater detail. Finally, the impact of large wildfires on the ambient levels of particulate matter in Southern California is discussed. The results of this work provide insight into single particles impacting the Southern California region, the relative source contributions to this region, and finally an examination of how atmospheric aging influences the ability to perform source apportionment.

Download or read book Single Particle Perspective on the Southern California Ozone Study written by Sylvia Harriet Pastor and published by . This book was released on 2003 with total page 1244 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Ambient Organic Aerosols where They Come From and where They are Going some More Slowly Than Others written by Christopher R. Ruehl and published by . This book was released on 2009 with total page 422 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Toxicity of Atmospheric Aerosols Methodologies Assays written by Fobang Liu and published by American Chemical Society. This book was released on 2023-06-06 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt: Atmospheric aerosols, or particulate matter (PM), are liquid or solid particles suspended in the air. Exposure to ambient PM is associated with multiple diseases and accounts for millions of premature deaths today. Although recognized as an important public health problem, PM’s toxicity and toxicological mechanisms are yet to be understood. Various methodologies and assays (i.e., procedures to determine the composition, quantity, or quality of a substance or a mixture) have been developed or employed to understand the components and characteristics of PM that best determine its toxicity. Efforts have also been spent to study the mechanisms of cellular signaling, stress, response, and physiological change, as well as complex multi-tissue effects upon PM exposure. These assays are diverse, spanning from in vitro acellular assays (i.e., chemical assays) to in vitro cellular and in vivo assays. Given that various methodologies and assays have been developed or employed, this digital primer aims to introduce the methodologies and fundamental principles used to study atmospheric aerosols’ toxicity and emerging new techniques. A comprehensive literature review of the scientific findings using these methodologies and assays is not the focus of this primer. The target audiences are senior undergraduates or beginning graduate students unfamiliar with aerosol science and toxicity measurements. An introductory overview of atmospheric aerosols and the motivations to study their toxicity before a detailed discussion of methodologies and assays in the toxicity research of atmospheric aerosols is provided. Beyond this, Toxicity of Atmospheric Aerosols: Methodologies & Assays serves as an assembly of the various methodologies and assays used in the toxicity research of atmospheric aerosols, saving readers time compared to searching from scattered resources.

Download or read book Regional Ambient Aerosol Study written by and published by . This book was released on 1999 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Ozone and Other Photochemical Oxidants written by and published by National Academies. This book was released on 1977-01-01 with total page 740 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Measurement Analysis and Remediation of Environmental Pollutants written by Tarun Gupta and published by Springer Nature. This book was released on 2019-10-08 with total page 474 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book discusses contamination of water, air, and soil media. The book covers health effects of such contamination and discusses remedial measures to improve the situation. Contributions by experts provide a comprehensive discussion on the latest developments in the detection and analysis of contaminants, enabling researchers to understand the evolution of these pollutants in real time and develop more accurate source apportionment of these pollutants. The contents of this book will be of interest to researchers, professionals, and policy makers alike.

Download or read book Studies of Ambient and Chamber Aerosol Composition Using the Aerosol Mass Spectrometer written by Jill Suzanne Craven and published by . This book was released on 2013 with total page 890 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 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 Southern California Air Quality Study Sampler Chemistry written by Richard J. Countess and published by . This book was released on 1989 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Interpretation of Mass Spectra written by Fred Warren McLafferty (Chemiker, USA) and published by . This book was released on 1973 with total page 278 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Chamber Studies of Secondary Organic Aerosol Formation written by Nga Lee Ng and published by . This book was released on 2007 with total page 972 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Epidemiologic Investigation to Identify Chronic Effects of Ambient Air Pollutants in Southern California written by John M. Peters and published by . This book was released on 2004 with total page 342 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Development and Application of Ambient Aerosol Concentrators to Conduct Health Effects Studies in the Los Angeles Basin written by John R. Froines and published by . This book was released on 2006 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Characterization of Ambient Aerosol Source and Processes During CalNex 2010 with Aerosol Mass Spectrometry written by José Luis Jiménez and published by . This book was released on 2013 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt: