Rapidly increasing interest in the problems of air pollution and source-receptor relationships has led to a significant expansion of knowledge in the field of atmospheric chemistry. In general the chemistry of atmospheric trace constituents is governed by the oxygen content of the atmosphere. Upon entering the atmosphere in a more or less reduced state, trace substances are oxidized via various pathways and the generated products are often precursors of acidic compounds. Beside oxidation processes occurring in the gas phase, gaseous compounds are often converted into solid aerosol particles. The various steps within gas-to-particle conversion are constantly interacting with condensation processes, which are caused by the tropospheric water content. Thus in addition to the gaseous state, a liquid and solid state exists within the troposphere. The solid phase consists of atmospheric conversion products or fly ash and mineral dust. The liquid phase consists of water, conversion products and soluble compounds. The chemistry occurring within this system is often referred to as hydrogeneous chemistry. The chemist interprets this term, however, more strictly as reactions which occur only at an interphase between phases. This, however, is not always what happens in the atmosphere. There are indeed heterogeneous processes such as reactions occurring on the surface of dry aerosol particles. But apart from these, we must focus as well on reactions in the homogeneous phase, which are single steps of consecutive reactions running through various phases.
Table of ContentsI Analytical and Experimental Methodology.- Multiphase Atmospheric Chemistry.- Laboratory and Field Studies of Gas-Aerosol Reactions.- Characterization of Air Particulate Matter By X-Ray, Raman And Mass Spectrometry Techniques.- Standardized Techniques for the Collection and Analysis of Precipitation.- The Peroxyoxalate Chemiluminescence and its Application to the Determination of Hydrogen Peroxide in Precipitation.- II Field Studies of Clouds, Fogs and Precipitation.- The Role of Cloudphysics In Atmospheric Multiphase Systems: Ten Basic Statements.- Field Studies of Cloud Chemistry and the Relative Importance of Various Mechanisms of the Incorporation of Sulfate and Nitrate into Cloud Water.- Radiation Fog Chemistry and Microphysics.- Investigation of the Wet and Dry Deposition of Acidic and Heavy-Metal Components.- Antarctic Precipitation Chemistry.- III Origin, Distribution and Removal of Atmospheric Trace Compounds in the Presence of Airborne Particles and Liquid Water.- Relations Between Aerosol Acidity and Ion Balance.- The Origin of Nitrous and Nitric Acid in the Atmosphere.- On the Importance of Light Hydrocarbons in Multiphase Atmospheric Systems.- Ambient Radical Concentrations in the Presence of Airborne Liquid Water.- IV Chemical Conversions in Multiphase Atmospheric Systems and their Physico Chemical Investigation.- Photochemistry of the Atmospheric Aqueous Phase.- Mass-Transport Considerations Pertinent to Aqueous Phase Reactions of Gases in Liquid-Water Clouds.- The Equilibrium Distribution of Atmospheric Gases Between the Two Phases of Liquid Water Clouds.- The Interaction of Sulfur Trioxede with Water Clusters.- Laboratory Studies of the Multiphase SIVVI conversion Rate.- Transition Metals as Potential Catalysts in Atmospheric Oxidation Processes.- Photocatalytic Degradation of Atmospheric Pollutants on the Surface of Metal Oxides.- V The Role of Multiphase Atmospheric Chemistry in Source-Receptor Considerations.- Acid Rain in North America: Concepts and Strategies.- Some Considerations of the Important Chemical Processes in Acid Deposition.- A Study of Cloudwater Acidity Downwind of Urban and Power Plant Sources.- Receptor Modeling Based on Elemental Analysis.- Uncertainties in Quantifying Source-Receptor Relationships for Atmospheric Acids.- Modes of Interaction of Air Pollutants with Spruce-Fir Forests: Summary and New Mechanisms.