This volume is concerned with the physics and the application of air pollution modeling on scales up to about 50 km. Its eight chapters, comprising the diverse points of view of seven authors, remain substantially in their original, lecture-note form. The result is not a smoothly flowing monograph but instead a richly textured, lively collection of the seasoned thoughts and perspectives of experienced researchers and practitioners.

This publication of the AMS contains all the lectures that were presented at the AMS Workshop on Meteorology and Environmental Assessment held in Boston, MA on September 29-October 3, 1975. Topics include: The dispersion of materials in the atmospheric boundary layer, atmospheric dispersion models for environmental pollution applications, plume rise predictions, turbulent diffusion and pollutant transport in shoreline environments, urban diffusion problems, atmospheric transformations of pollutants, observational systems and techniques in air pollution meteorology, and federal government requirements for environmental impact assessment.

This volume covers the latest scientific developments in the real world applications of pollution modeling. Topics covered include: the role of atmospheric models in air pollution policy and abatement strategies; integrated regional modelling; global and long-range transport; aerosols as atmospheric contaminants; model assessment and verification; and application of new concepts in different regions of the world.

Finishing this book is giving me a mixture of relief, satisfaction and frus tration. Relief, for the completion of a project that has taken too many of my evenings and weekends and that, in the last several months, has become almost an obsession. Satisfaction, for the optimistic feeling that this book, in spite of its many shortcomings and imbalances, will be of some help to the air pollution scientific community. Frustration, for the impossibility of incorporating newly available material that would require another major review of several key chap ters - an effort that is currently beyond my energies but not beyond my desires. The first canovaccio of this book came out in 1980 when I was invited by Computational Mechanics in the United Kingdom to give my first Air Pollution Modeling course. The course material, in the form of transparencies, expanded, year after year, thus providing a growing working basis. In 1985, the ECC Joint Research Center in Ispra, Italy, asked me to prepare a critical survey of mathe matical models of atmospheric pollution, transport and deposition. This support gave me the opportunity to prepare a sort of "first draft" of the book, which I expanded in the following years.

Atmospheric chemistry is one of the fastest growing fields in the earth sciences. Until now, however, there has been no book designed to help students capture the essence of the subject in a brief course of study. Daniel Jacob, a leading researcher and teacher in the field, addresses that problem by presenting the first textbook on atmospheric chemistry for a one-semester course. Based on the approach he developed in his class at Harvard, Jacob introduces students in clear and concise chapters to the fundamentals as well as the latest ideas and findings in the field. Jacob's aim is to show students how to use basic principles of physics and chemistry to describe a complex system such as the atmosphere. He also seeks to give students an overview of the current state of research and the work that led to this point. Jacob begins with atmospheric structure, design of simple models, atmospheric transport, and the continuity equation, and continues with geochemical cycles, the greenhouse effect, aerosols, stratospheric ozone, the oxidizing power of the atmosphere, smog, and acid rain. Each chapter concludes with a problem set based on recent scientific literature. This is a novel approach to problem-set writing, and one that successfully introduces students to the prevailing issues. This is a major contribution to a growing area of study and will be welcomed enthusiastically by students and teachers alike.

Proceedings of the Millennium NATO/CCMS International Technical Meeting on Air Pollution Modeling and its Application, held May 15-19 in Boulder, Colorado. This volume is the latest in a series of proceedings dating back to 1971. The book addresses the problem of air pollution and reports the latest findings and developments in air pollution modeling, from a truly international list of contributors.

The 20th International Technical Meeting on Air Pollution Modelling and Its Application was held in Valencia, Spain, during late 1993. At this conference, a new record of abstracts was submitted, a new record of scientists participated, and a new record of countries was represented. This clearly indicates society's continuous and growing interest in, as well as importance of, the complexities associated with the modelling of air pollution. The conference addressed the following main subjects: integrated regional modelling, global and long-range transport, new modelling developments, accidental releases, and model assess ment and verification. In addition, two project-oriented workshops were organized as part of the conference. The many contributing authors and scientists taking active part in the discussions following the papers, have made this proceeding a record of the current status in the field of air pollu tion modelling. We want to express our gratitude to their efforts. We also wish to extend our gratitude to the sponsors that made this conference possible. In addition to financial support from NATOjCCMS the conference received contributions from CEAM, the European Asso ciation for the Science of Air Pollution, Danish Center for Air Research, and Ris0 National Laboratory. A special grant was given by NATOjCCMS to facilitate attendance of scientists from Central and Eastern Europe. We also wish to express our gratitude to Rosa Salvador and Pilar Zamora of CEAM, who laboriously organized the conference pre-proceedings, and to Anne N0rregaard and Ulla Riis Christiansen of Ris0 National Laboratory, who seved as conference secretariat.