Heterogeneous reactions have the potential to significantly impact urban ozone formation and total reactivity of the atmosphere. This dissertation used comparisons between photochemical modeling predictions and field measurements to examine heterogeneous N2O5 chemistry in Southeast Texas. Heterogeneous reactions of N2O5 can lead to two different products: nitric acid (HNO3) and nitryl chloride (ClNO2). The formation of HNO3 results in a loss of reactive nitrogen from the atmosphere. In contrast ClNO2 photolysis forms Cl radicals and NO2, both of which promote ozone formation in the troposphere. Preliminary modeling identified key uncertainties and the need to perform more refined modeling which included updated PM emissions estimates, an updated gas-phase N2O5 hydrolysis reaction rate constant, updated reactive uptake coefficients, and the inclusion of ClNO2 as a product of heterogeneous N2O5 uptake. Refined modeling which incorporated all of these improvements was carried out and was the first comprehensive modeling of this chemistry performed for an urban air pollution episode. Comparisons of aerosol surface area concentrations, N2O5 concentrations, HNO3 concentrations, and ClNO2 concentrations with ambient data showed that model predictions were reasonable. The exceptions to this were 1) over-predictions of aerosol surface area concentration peaks at altitudes above 1500 meters and 2) over-prediction of N2O5 concentrations in the Houston Ship Channel. Further analysis is needed to identify the reasons for these over-predictions. Other key findings from this modeling include the model prediction of inland chlorine concentrations high enough to form ClNO2 and the prediction that a large portion of atmospheric chlorine is cycled through ClNO2, therefore making the inclusion of ClNO2 into photochemical models essential for properly simulating chlorine chemistry. In addition, modeling suggested that the chemistry leads to significant increases of NO[subscript x] at night, but decreases in daytime NO[subscript x] concentrations and that the overall effect was to decrease ozone concentrations. Further investigation into the effect of ClNO2 as a chlorine source showed that likely ozone increases in the Houston area caused by the presence of this compound are on the order of several ppb. Further analyses showed that vertical dispersion and local atmospheric composition moderated the effect of nitryl chloride on ozone mixing ratios.

Dinitrogen pentoxide (N2O5) is a naturally occurring gas-phase nitrating agent that acts as a nocturnal NOx reservoir (NOx ≡ NO + NO2) in the atmosphere. The heterogeneous reaction of N2O5 at aqueous interfaces can serve as a chain terminating reaction in the catalytic cycling of NOx radicals that generate ozone in the lower atmosphere. A molecular mechanism for the heterogeneous reaction of N2O5 has remained elusive but is generally thought to proceed through hydrolysis forming nitrate in the condensed phase. It has been shown previously that N2O5 can also react with aqueous chloride, forming nitryl chloride (ClNO2). Upon evaporation to the gas phase, ClNO2 can photolyze, regenerating NO2 and a chlorine radical. The fraction of N2O5 that is converted to ClNO2 following reactive uptake to aqueous interfaces ([uppercase Phi]ClNO2) depends strongly on the chloride concentration. Although well established for aqueous solutions containing only chloride, recent field observations indicate that parameterizations of [uppercase Phi]ClNO2 based on laboratory measurements uniformly overpredict [uppercase Phi]ClNO2 for more chemically complex interfaces. In this thesis, I expand upon existing studies of N2O5 reaction with chloride in water to investigate alternative solutes and solvents as well as mixed salt solutions that are more relevant proxies for atmospheric interfaces. In chapters 2 and 3, I report and interpret measurements of the nitryl chloride (ClNO2) branching fraction following reactive uptake of N2O5 to mixed organic and inorganic solutions representative of atmospheric interfaces. For solutions containing 0.5 M NaCl, [uppercase Phi]ClNO2 is reduced from 0.85 +/- 0.03 to 0.32 +/- 0.14 upon the addition of 2.0 M Na2SO4, and to 0.18 +/- 0.03 upon the addition of 0.5 M NaAc. The results indicate that anions ubiquitous in atmospheric aerosol, commonly considered to be unreactive, may regulate the production of reactive gases such as ClNO2. In chapter 4, I investigate the parallel reaction of N2O5 with bromide (sodium bromide, NaBr, and tetrahexylammonium bromide, THABr) and compare the observed product branching fractions with those observed for aqueous chloride solutions. In the second part of chapter 4, I explore the product branching fractions for Br2 in a new solvent, glycerol, to represent the organic component of aerosol.

A quantitative introduction to atmospheric science for students and professionals who want to understand and apply basic meteorological concepts but who are not ready for calculus.

This book’s main objective is to decipher for the reader the main processes in the atmosphere and the quantification of air pollution effects on humans and the environment, through first principles of meteorology and modelling/measurement approaches. The understanding of the complex sequence of events, starting from the emission of air pollutants into the atmosphere to the human health effects as the final event, is necessary for the prognosis of potential risk to humans from specific chemical compounds and mixtures of them. It fills a gap in the literature by providing a solid grounding in the first principles of meteorology and air pollution, making it particularly useful for undergraduate students. Its broad scope makes it a valuable text in many related disciplines, containing a comprehensive and integrated methodology to study the first principles of air pollution, meteorology, indoor air pollution, and human exposure. Problem-solving exercises help to reinforce concepts.

Atmospheric Science, Second Edition, is the long-awaited update of the classic atmospheric science text, which helped define the field nearly 30 years ago and has served as the cornerstone for most university curricula. Now students and professionals alike can use this updated classic to understand atmospheric phenomena in the context of the latest discoveries, and prepare themselves for more advanced study and real-life problem solving. This latest edition of Atmospheric Science, has been revamped in terms of content and appearance. It contains new chapters on atmospheric chemistry, the Earth system, the atmospheric boundary layer, and climate, as well as enhanced treatment of atmospheric dynamics, radiative transfer, severe storms, and global warming. The authors illustrate concepts with full-color, state-of-the-art imagery and cover a vast amount of new information in the field. Extensive numerical and qualitative exercises help students apply basic physical principles to atmospheric problems. There are also biographical footnotes summarizing the work of key scientists, along with a student companion website that hosts climate data; answers to quantitative exercises; full solutions to selected exercises; skew-T log p chart; related links, appendices; and more. The instructor website features: instructor's guide; solutions to quantitative exercises; electronic figures from the book; plus supplementary images for use in classroom presentations. Meteorology students at both advanced undergraduate and graduate levels will find this book extremely useful. - Full-color satellite imagery and cloud photographs illustrate principles throughout - Extensive numerical and qualitative exercises emphasize the application of basic physical principles to problems in the atmospheric sciences - Biographical footnotes summarize the lives and work of scientists mentioned in the text, and provide students with a sense of the long history of meteorology - Companion website encourages more advanced exploration of text topics: supplementary information, images, and bonus exercises

The Periodic Table: Nature’s Building Blocks: An Introduction to the Naturally Occurring Elements, Their Origins and Their Uses addresses how minerals and their elements are used, where the elements come from in nature, and their applications in modern society. The book is structured in a logical way using the periodic table as its outline. It begins with an introduction of the history of the periodic table and a short introduction to mineralogy. Element sections contain their history, how they were discovered, and a description of the minerals that contain the element. Sections conclude with our current use of each element. Abundant color photos of some of the most characteristic minerals containing the element accompany the discussion. Ideal for students and researchers working in inorganic chemistry, minerology and geology, this book provides the foundational knowledge needed for successful study and work in this exciting area. Describes the link between geology, minerals and chemistry to show how chemistry relies on elements from nature Emphasizes the connection between geology, mineralogy and daily life, showing how minerals contribute to the things we use and in our modern economy Contains abundant color photos of each mineral that bring the periodic table to life

Thoroughly restructured and updated with new findings and new features The Second Edition of this internationally acclaimed text presents the latest developments in atmospheric science. It continues to be the premier text for both a rigorous and a complete treatment of the chemistry of the atmosphere, covering such pivotal topics as: * Chemistry of the stratosphere and troposphere * Formation, growth, dynamics, and properties of aerosols * Meteorology of air pollution * Transport, diffusion, and removal of species in the atmosphere * Formation and chemistry of clouds * Interaction of atmospheric chemistry and climate * Radiative and climatic effects of gases and particles * Formulation of mathematical chemical/transport models of the atmosphere All chapters develop results based on fundamental principles, enabling the reader to build a solid understanding of the science underlying atmospheric processes. Among the new material are three new chapters: Atmospheric Radiation and Photochemistry, General Circulation of the Atmosphere, and Global Cycles. In addition, the chapters Stratospheric Chemistry, Tropospheric Chemistry, and Organic Atmospheric Aerosols have been rewritten to reflect the latest findings. Readers familiar with the First Edition will discover a text with new structures and new features that greatly aid learning. Many examples are set off in the text to help readers work through the application of concepts. Advanced material has been moved to appendices. Finally, many new problems, coded by degree of difficulty, have been added. A solutions manual is available. Thoroughly updated and restructured, the Second Edition of Atmospheric Chemistry and Physics is an ideal textbook for upper-level undergraduate and graduate students, as well as a reference for researchers in environmental engineering, meteorology, chemistry, and the atmospheric sciences. Click here to Download the Solutions Manual for Academic Adopters: http://www.wiley.com/WileyCDA/Section/id-292291.html

Despite more than 20 years of regulatory efforts, concern is widespread that ozone pollution in the lower atmosphere, or troposphere, threatens the health of humans, animals, and vegetation. This book discusses how scientific information can be used to develop more effective regulations to control ozone. Rethinking the Ozone Problem in Urban and Regional Air Pollution discusses: The latest data and analysis on how tropospheric ozone is formed. How well our measurement techniques are functioning. Deficiencies in efforts to date to control the problem. Approaches to reducing ozone precursor emissions that hold the most promise. What additional research is needed. With a wealth of technical information, the book discusses atmospheric chemistry, the role of oxides of nitrogen (NOx) and volatile organic compounds (VOCs) in ozone formation, monitoring and modeling the formation and transport processes, and the potential contribution of alternative fuels to solving the tropospheric ozone problem. The committee discusses criteria for designing more effective ozone control efforts. Because of its direct bearing on decisions to be made under the Clean Air Act, this book should be of great interest to environmental advocates, industry, and the regulatory community as well as scientists, faculty, and students.

New edition of introductory textbook, ideal for students taking a course on air pollution and global warming, whatever their background. Comprehensive introduction to the history and science of the major air pollution and climate problems facing the world today, as well as energy and policy solutions to those problems.