Transport and Chemical Transformation of Pollutants in the Troposphere – serie

The "European Experiment on the Transport and Transformation of Environmentally Relevant Trace Constituents over Europe" (EUROTRAC) was established in 1986 to tackle the scientific problem and combine the expertise, knowledge and resources in Europe, in order to apply them over a large region covering the greater part of the continent. EUROTRAC is a coordinated multidisciplinary scientific research project involving field measurements, laboratory studies, instrument development and development of comprehensive computer models for the simulation of the physical and chemical processes in the lower atmosphere.

The biosphere is the ultimate sink for air pollutants and is also the source of many precursors for the formation of photo-oxidants. In any analysis of air pollution and for determining source-receptor relationships, reliable emission and pollutant concentrations or depositions must be taken into account, together with their interactions between the atmosphere and the biosphere. This book presents a number of authoritative review articles covering topics which include biosphere-atmosphere exchange of ammonia, nitrogen oxides, ozone and sulfur-containing gases, the biological mechanisms involved in the exchange of trace gases, as well as generalizations of deposition over Europe.

This volume presents the results and conclusions of the Application Project of EUROTRAC about the state of the troposphere over Europe, drawing from the plethora of scientific results. The various findings and recommendations on local, regional and global scales illustrate the complexities of the situation and indicate the subsequent difficulties which face environmental policy makers seeking to find ways to abate pollution on a regional scale. The book is recommended first for the scientific and policy-related information which it contains. In addition, the book is an excellent illustration of how the scientific programme can be evaluated in order to draw conclusions which are useful in policy development.

Among the chemical and physical processes involved in the transformation of pollutants between their sources and their ultimate deposition, those associated with clouds, aerosols and precipitation must be rated as the most difficult both to study and to understand. This book presents a variety of recent advances in this field, including the properties and composition of aerosol particles, chemical transformation and scavenging processes, the relationship between liquid-phase chemistry and cloud micro-physics, entrainment, evaporation and deposition, trends in high Alpine pollution, transport processes, and developments in instrumentation. This book is Volume 5 in the ten-volume series on Transport and Chemical Transformation of Pollutants in the Troposphere.

Jens Bosenberg Max-Planck-Institut fur Meteorologie, Bundesstr. 55, D-20146 Hamburg, Germany TESLAS, which stands for Tropospheric Environmental Studies by Laser Sounding, was formed in November 1987 as a subproject of EUROTRAC to enhance the measurement capabilities for vertical profiling of ozone in the troposphere by means of laser remote sensing. For studies of several atmospheric processes related to the formation and redistribution of photo-oxidants there was a clear need for measuring extended time series with appropriate vertical and temporal resolution. These could not be obtained by conventional in situ techniques, at least not with affordable effort, so remote sensing appeared to be the best way to obtain the required information. At the beginning of the subproject, some Differential Absorption Lidar (DIAL) systems for measuring the vertical distribution of ozone already existed, but their use was restricted to very few laboratories and very few measurement campaigns, since the instruments were highly complex, rather unreliable, and required extensive efforts for maintenance and operation by skilled scientists. In addition, the accuracy of these measurements under a variety of meteorological conditions was not really well established. The main tasks within TESLAS therefore were to develop fully the DIAL-methodology for remote sensing of tropospheric ozone, and to develop instruments which are accurate, reliable, easy to operate, and suitable for field deployment or airborne operation.

The end result of policy-related experimental and theoretical scientific work on the abatement of atmospheric emissions is a hierarchy of computer models that can be used to analyse and predict the behaviour of pollutants on urban, local regional and global scales. Such models are required to simulate an extremely complex natural situation in which a non-linear chemistry must be included together with the vagaries of the meteorology and the terrain. This book describes recent advances in the development and application of models on all scales, and in the techniques for the estimation and verification of emissions. It includes reviews of recent work together with detailed results and provides a useful picture of the field in a European context.

One of the principal concerns in recent years regarding the atmospheric environment has been the formation of ozone and other photo-oxidants over much of Europe in the summer. Ozone is formed in the atmosphere by a complex series of chemical reactions in the presence of sunlight from volatile organic compounds and nitrogen oxides. As the reactions take place in air flows determined by the detailed meteorological situation, the measurement, interpretation, understanding and modelling of the levels, fluxes and origins of the ozone are extremely difficult. The present volume reviews several of the currently important questions and presents detailed reports from investigators all over the continent. As such, it provides insight into the current scientific views about ozone in Europe.

As the regional models required to understand and control the generation, distribution and deposition of air pollutants become more precise, the need to understand the detailed effects of hilly and mountainous terrain becomes more acute. The Alpine regions and the mountainous Mediterranean coasts have large effets on the way the pollutant burden is spread in their areas. Similarly an understanding of the effects of chemical and physical processes controlling pollutant deposition and the emission of biogenic compounds is essential to the correct modelling of the coastal regions which surround so much of Europe.The results from two projects on these problems are presented in this volume: one involved a series of field campaigns in the Alps and in the Rhine valley, the other involves ships and platforms in the North Sea and also in the Mediterranean.

The biosphere is the ultimate sink for air pollutants and is also the source of many precursors for the formation of photo-oxidants. In any analysis of air pollution and for determining source-receptor relationships, reliable emission and pollutant concentrations or depositions must be taken into account, together with their interactions between the atmosphere and the biosphere. This book presents a number of authoritative review articles covering topics which include biosphere-atmosphere exchange of ammonia, nitrogen oxides, ozone and sulfur-containing gases, the biological mechanisms involved in the exchange of trace gases, as well as generalizations of deposition over Europe.

The growth in our understanding of the production, transformation and loss of pollutants and trace substances in the atmosphere has followed closely the development of instrumentation for both in situ and remote measurements of the minute concentrations and fluxes of trace substances. In recent times the requirement has been for instruments which have a fast response, are chemically specific, and sensitive enough to detect small changes in concentrations at ppb and ppt levels. This book gives an account of such techniques. Each technique is reviewed and then the results of a number of detailed studies are presented. The book is Volume 8 of the series on Transport and Chemical Transformation of Pollutants in the Troposphere.

The end result of policy-related experimental and theoretical scientific work on the abatement of atmospheric emissions is a hierarchy of computer models that can be used to analyse and predict the behaviour of pollutants on urban, local regional and global scales. Such models are required to simulate an extremely complex natural situation in which a non-linear chemistry must be included together with the vagaries of the meteorology and the terrain. This book describes recent advances in the development and application of models on all scales, and in the techniques for the estimation and verification of emissions. It includes reviews of recent work together with detailed results and provides a useful picture of the field in a European context.

As the regional models required to understand and control the generation, distribution and deposition of air pollutants become more precise, the need to understand the detailed effects of hilly and mountainous terrain becomes more acute. The Alpine regions and the mountainous Mediterranean coasts have large effets on the way the pollutant burden is spread in their areas. Similarly an understanding of the effects of chemical and physical processes controlling pollutant deposition and the emission of biogenic compounds is essential to the correct modelling of the coastal regions which surround so much of Europe.The results from two projects on these problems are presented in this volume: one involved a series of field campaigns in the Alps and in the Rhine valley, the other involves ships and platforms in the North Sea and also in the Mediterranean.

One of the principal concerns in recent years regarding the atmospheric environment has been the formation of ozone and other photo-oxidants over much of Europe in the summer. Ozone is formed in the atmosphere by a complex series of chemical reactions in the presence of sunlight from volatile organic compounds and nitrogen oxides. As the reactions take place in air flows determined by the detailed meteorological situation, the measurement, interpretation, understanding and modelling of the levels, fluxes and origins of the ozone are extremely difficult. The present volume reviews several of the currently important questions and presents detailed reports from investigators all over the continent. As such, it provides insight into the current scientific views about ozone in Europe.

EUROTRAC is the EUREKA environmental project studying the transport and chemical transformation of pollutants in the troposphere over Europe. At its inception in 1988 it had three aims: * to increase the basic understanding of atmospheric science; * to promote the technological development of sensitive, specific, fast-response instrumentation for environmental research and monitoring; and * to improve the scientific basis for taking future political decisions on environmental management within Europe. It was clear at an early stage, as the fourteen subprojects were formed and more than two hundred research groups in twenty-four countries were incorporated, that the first aim would readily be achieved. An ample demonstration that the early indications were correct is provided in the other volumes in this series which describe the scientific progress made. Substantial progress was also made towards achieving the second aim although some problems were encountered, mainly due to the high cost of the technological development required.

Among the chemical and physical processes involved in the transformation of pollutants between their sources and their ultimate deposition, those associated with clouds, aerosols and precipitation must be rated as the most difficult both to study and to understand. This book presents a variety of recent advances in this field, including the properties and composition of aerosol particles, chemical transformation and scavenging processes, the relationship between liquid-phase chemistry and cloud micro-physics, entrainment, evaporation and deposition, trends in high Alpine pollution, transport processes, and developments in instrumentation. This book is Volume 5 in the ten-volume series on Transport and Chemical Transformation of Pollutants in the Troposphere.

Oxidation and removal of atmospheric constituents involve complex sequences of reactions which can lead to the production of photo-oxidants such as ozone. In order to understand and model these complex reaction sequences, it is necessary to have a comprehensive understanding of reaction mechanisms and accurate estimates of kinetic parameters for relevant gas-phase atmospheric reactions. This book presents recent advances in the field and includes the following topics: e.g. the oxidation of simple organic compounds, NOx kinetics and mechanisms, OH radical production and rate constants for the OH attack on more complex organic compounds, peroxy and alkoxy radical reactions, photo-oxidation of aromatic and biogenic compounds, and the interaction between radical species.

A major environmental concern is the increasing burden on all scales of photo-oxidants, acidifying substances and potential nutrients in the troposphere. These lead to episodes of summer smog, and appreciable damage to eco-systems both on land and at sea. Underlying the environmental effects is the complex scientific problem of linking the man-made and biological emissions to the myriad chemical reactions that transform the pollutants as they are transported to and deposited in the surroundings and also pristine areas remote from the sources. The project, the scientific results of which are described in this book, was set up to study the problem in an inter-disciplinary way by co-ordinating the work of more than 150 research groups in some 20 countries.