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Chemistry of the Upper and Lower Atmosphere: Theory, Experiments, and Applications

TL;DR: A detailed overview of the chemistry of Polluted and Remote Atmospheres can be found in this paper, where the OZIPR model is used to simulate the formation of gases and particles in the Troposphere.
Abstract: Overview of the Chemistry of Polluted and Remote Atmospheres. The Atmospheric System. Spectroscopy and Photochemistry: Fundamentals. Photochemistry of Important Atmospheric Species. Kinetics and Atmospheric Chemistry. Rates and Mechanisms of Gas-Phase Reactions in Irradiated Organic-NOx-Air Mixtures. Chemistry of Inorganic Nitrogen Compounds. Acid Deposition: Formation and Fates of Inorganic and Organic Acids in the Troposphere. Particles in the Troposphere. Airborne Polycyclic Aromatic Hydrocarbons and Their Derivatives: Atmospheric Chemistry and Toxicological Implications. Analytical Methods and Typical Atmospheric Concentrations for Gases and Particles. Homogeneous and Heterogeneous Chemistry in the Stratosphere. Scientific Basis for Control of Halogenated Organics. Global Tropospheric Chemistry and Climate Change. Indoor Air Pollution: Sources, Levels, Chemistry, and Fates. Applications of Atmospheric Chemistry: Air Pollution Control Strategies and Risk Assessments for Tropospheric Ozone and Associated Photochemical Oxidants, Acids, Particles, and Hazardous Air Pollutants. Appendix I: Enthalpies of Formation of Some Gaseous Molecules, Atoms, and Free Radicals at 298 K. Appendix II: Bond Dissociation Energies. Appendix III: Running the OZIPR Model. Appendix IV: Some Relevant Web Sites. Appendix V: Pressures and Temperatures for Standard Atmosphere. Appendix VI: Answers to Selected Problems. Subject Index.
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Journal ArticleDOI
TL;DR: In this article, an overview of the atmospheric degradation mechanisms for SOA precursors, gas-particle partitioning theory and analytical techniques used to determine the chemical composition of SOA is presented.
Abstract: Secondary organic aerosol (SOA) accounts for a significant fraction of ambient tropospheric aerosol and a detailed knowledge of the formation, properties and transformation of SOA is therefore required to evaluate its impact on atmospheric processes, climate and human health. The chemical and physical processes associated with SOA formation are complex and varied, and, despite considerable progress in recent years, a quantitative and predictive understanding of SOA formation does not exist and therefore represents a major research challenge in atmospheric science. This review begins with an update on the current state of knowledge on the global SOA budget and is followed by an overview of the atmospheric degradation mechanisms for SOA precursors, gas-particle partitioning theory and the analytical techniques used to determine the chemical composition of SOA. A survey of recent laboratory, field and modeling studies is also presented. The following topical and emerging issues are highlighted and discussed in detail: molecular characterization of biogenic SOA constituents, condensed phase reactions and oligomerization, the interaction of atmospheric organic components with sulfuric acid, the chemical and photochemical processing of organics in the atmospheric aqueous phase, aerosol formation from real plant emissions, interaction of atmospheric organic components with water, thermodynamics and mixtures in atmospheric models. Finally, the major challenges ahead in laboratory, field and modeling studies of SOA are discussed and recommendations for future research directions are proposed.

3,324 citations

Journal ArticleDOI
TL;DR: The Indian Ocean Experiment (INDOEX) documented this Indo-Asian haze at scales ranging from individual particles to its contribution to the regional climate forcing as discussed by the authors, and integrated the multiplatform observations (satellites, aircraft, ships, surface stations, and balloons) with one-and four-dimensional models to derive the regional aerosol forcing resulting from the direct, the semidirect and the two indirect effects.
Abstract: Every year, from December to April, anthropogenic haze spreads over most of the North Indian Ocean, and South and Southeast Asia. The Indian Ocean Experiment (INDOEX) documented this Indo-Asian haze at scales ranging from individual particles to its contribution to the regional climate forcing. This study integrates the multiplatform observations (satellites, aircraft, ships, surface stations, and balloons) with one- and four-dimensional models to derive the regional aerosol forcing resulting from the direct, the semidirect and the two indirect effects. The haze particles consisted of several inorganic and carbonaceous species, including absorbing black carbon clusters, fly ash, and mineral dust. The most striking result was the large loading of aerosols over most of the South Asian region and the North Indian Ocean. The January to March 1999 visible optical depths were about 0.5 over most of the continent and reached values as large as 0.2 over the equatorial Indian ocean due to long-range transport. The aerosol layer extended as high as 3 km. Black carbon contributed about 14% to the fine particle mass and 11% to the visible optical depth. The single-scattering albedo estimated by several independent methods was consistently around 0.9 both inland and over the open ocean. Anthropogenic sources contributed as much as 80% (±10%) to the aerosol loading and the optical depth. The in situ data, which clearly support the existence of the first indirect effect (increased aerosol concentration producing more cloud drops with smaller effective radii), are used to develop a composite indirect effect scheme. The Indo-Asian aerosols impact the radiative forcing through a complex set of heating (positive forcing) and cooling (negative forcing) processes. Clouds and black carbon emerge as the major players. The dominant factor, however, is the large negative forcing (-20±4 W m^(−2)) at the surface and the comparably large atmospheric heating. Regionally, the absorbing haze decreased the surface solar radiation by an amount comparable to 50% of the total ocean heat flux and nearly doubled the lower tropospheric solar heating. We demonstrate with a general circulation model how this additional heating significantly perturbs the tropical rainfall patterns and the hydrological cycle with implications to global climate.

1,371 citations

Journal ArticleDOI
TL;DR: In this paper, an update to the previous protocol is presented, which has been used to define degradation schemes for 107 non-aromatic VOC as part of version 3 of the Master Chemical Mechanism (MCM v3).
Abstract: . Kinetic and mechanistic data relevant to the tropospheric degradation of volatile organic compounds (VOC), and the production of secondary pollutants, have previously been used to define a protocol which underpinned the construction of a near-explicit Master Chemical Mechanism. In this paper, an update to the previous protocol is presented, which has been used to define degradation schemes for 107 non-aromatic VOC as part of version 3 of the Master Chemical Mechanism (MCM v3). The treatment of 18 aromatic VOC is described in a companion paper. The protocol is divided into a series of subsections describing initiation reactions, the reactions of the radical intermediates and the further degradation of first and subsequent generation products. Emphasis is placed on updating the previous information, and outlining the methodology which is specifically applicable to VOC not considered previously (e.g. a - and b -pinene). The present protocol aims to take into consideration work available in the open literature up to the beginning of 2001, and some other studies known by the authors which were under review at the time. Application of MCM v3 in appropriate box models indicates that the representation of isoprene degradation provides a good description of the speciated distribution of oxygenated organic products observed in reported field studies where isoprene was the dominant emitted hydrocarbon, and that the a -pinene degradation chemistry provides a good description of the time dependence of key gas phase species in a -pinene/NOX photo-oxidation experiments carried out in the European Photoreactor (EUPHORE). Photochemical Ozone Creation Potentials (POCP) have been calculated for the 106 non-aromatic non-methane VOC in MCM v3 for idealised conditions appropriate to north-west Europe, using a photochemical trajectory model. The POCP values provide a measure of the relative ozone forming abilities of the VOC. Where applicable, the values are compared with those calculated with previous versions of the MCM.

1,274 citations

Journal ArticleDOI
TL;DR: A survey of the literature was conducted to review historical and current surface ozone data from background stations in Canada, United States and around the world for the purpose of characterizing background levels and trends, present plausible explanations for observed trends and explore projections of future ozone levels as discussed by the authors.

1,104 citations

Book
01 Jan 1986
TL;DR: The field of atmospheric chemistry is very broad, both in the problems addressed and in the approaches taken, and addresses chemistry from the lower to the upper atmosphere, in remote and polluted regions, from marine to continental areas, and both outdoors and indoors.
Abstract: The field of atmospheric chemistry is very broad, both in the problems addressed and in the approaches taken. Thus, it includes laboratory and theoretical studies, field measurements, and modeling, and addresses chemistry from the lower to the upper atmosphere, in remote and polluted regions, from marine to continental areas, and both outdoors and indoors. Given this complexity, it is impossible to capture all aspects with the limited number of articles that can be included in a special feature. Thus, what follows should be taken as illustrative rather than inclusive. The genesis of the field of atmospheric chemistry lies in air pollution in the troposphere (lower atmosphere), for which there is documentation at least as long ago as the 13th century. Dramatic incidents of excess deaths such as in the Meuse Valley, Belgium, in 1930 (1), and in London, England, in 1952 (2) brought public and scientific attention to “smog” (smog = smoke + fog) and, in particular, to the problem of sulfur dioxide and sulfate particles it forms in air, as well as to direct emissions of particles from combustion sources. Around 1950, what initially appeared to be a different kind of smog, now known as photochemical air pollution, was recognized in the Los Angeles area. The seminal work of Haagen-Smit demonstrated that the necessary ingredients (primary pollutants) were volatile organic compounds (VOC), oxides of nitrogen (NOx = NO + NO2), and sunlight. The wavelengths available to drive photochemistry at the earth's surface are restricted to … 1E-mail: bjfinlay{at}uci.edu.

1,029 citations


Cites background from "Chemistry of the Upper and Lower At..."

  • ...Thewavelengths available to drive photochemistry at the earth’s surface are restricted to λ > 290 nm due to the filtering of shorter wavelengths by ozone naturally produced in the stratosphere (upper atmosphere) via the Chapman Cycle (3)....

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  • ...of shorter wavelengths by ozone naturally produced in the stratosphere (upper atmosphere) via the Chapman Cycle (3)....

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