In 1969 the North Atlantic Treaty Organization established the Committee on the Challenges of Modern Society. Air Pollution was from the start one of the priority problems under study within the framework of the pilot studies undertaken by this Committee. The organization of a yearly symposium dealing with air pollution modeling and its application is one of the main activities within the pilot study in relation to air pollution. After being organized for five years by the United States and for five years by the Federal Republic of Germany, Belgium, represented by the Prime Minister's Office for science Policy, became responsible in 1980 for the organization of this symposium. This volume contains the papers presented at the 14th Inter national Technical Meeting on Air Pollution Modeling and its Appli cation held in Copenhagen, Denmark, from 27th to 30th September 1983. This meeting was jointly organized by the Prime Minister's Office for Science Policy, Belgium, and the National Agency of Environmental Protection, Air Pollution Laboratory, Ris~ National Laboratory, Denmark. The conference was attended by 103 partici pants and 43 papers have been presented. The members of the se lection committee of the 14th I.T.M. were A. Berger (Chairman, Belgium), W. Klug (Federal Republic of Germany), K. Demerjian (United States of America), L. Santomauro (Italy), R. Van Dop (The Netherlands), R.E. Turner (Canada), C. De Wispelaere (Coordinator, Belgium).

In 1969 the North Atlantic Treaty Organization established the Committee on the Challenges of Modern Society. Air Pollution was from the start one of the priority problems under study within the framework of the pilot studies undertaken by this Committee. The organization of a yearly symposium dealing with air pollution modeling and its application is one of the main activities within the pilot study in relation to air pollution. After being organized for five years by the United States and for five years by the Federal Republic of Germany, Belgium, represented by the Prime Minister's Office for science Policy, became responsible in 1980 for the organization of this symposium. This volume contains the papers presented at the 14th Inter national Technical Meeting on Air Pollution Modeling and its Appli cation held in Copenhagen, Denmark, from 27th to 30th September 1983. This meeting was jointly organized by the Prime Minister's Office for Science Policy, Belgium, and the National Agency of Environmental Protection, Air Pollution Laboratory, Ris~ National Laboratory, Denmark. The conference was attended by 103 partici pants and 43 papers have been presented. The members of the se lection committee of the 14th I.T.M. were A. Berger (Chairman, Belgium), W. Klug (Federal Republic of Germany), K. Demerjian (United States of America), L. Santomauro (Italy), R. Van Dop (The Netherlands), R.E. Turner (Canada), C. De Wispelaere (Coordinator, Belgium).

The interest in air pollution modelling has shown substantial growth over the last five years. This was particularly evident by the increasing number of participants attending the NATO/CCMS International Technical Meetings on Air Pollution modelling and its Application. At the last meeting 118 papers and posters were selected from an abundance of submitted abstracts divided over five modelling topics: (i) model assessment and verification, including policy applications, (ii) air pollution modelling in coastal areas with emphasis on the mediterranean region, (iii) accidental atmospheric releases, including warning systems and regulations, (iv) modelling of global and long-range transport and (v) new developments in turbulent diffusion. A round-table discussion chaired by John Irwin (USA) and Jan Kretzschmar (Belgium) on the harmonization of air pollution models was attended by more than 50 scientists and is reported in these proceedings. The opening paper addressed the main issue of this conference: modelling over complex terrain. Of particular interest were coastal areas where the surface inhomogeneities introduce small-scale circulation and varying atmospheric stability, often combined with a complex topography. As the conference was located on the beautiful island of Crete, problems faced by the host nation, particularly Athens and its environs were obvious examples for consideration. These together with other regions with similar geographical features were addressed. Heavily populated and industrialized as they often are, air quality is generally poor there and emission regulations are desired. Obviously, a major task of air pollution dispersion modelling is to assist policy makers in formulating sensible regulations.

In 1969 the North Atlantic Treaty Organisation (NATO) established the Committee on Challenges of Modern Society (CCMS). The subject of air pol- tion was from the start, one of the priority problems under study within the fra- work of various pilot studies undertaken by this committee. The organization of a periodic conference dealing with air pollution modeling and its application has become one of the main activities within the pilot study relating to air pollution. The first five international conferences were organized by the United States as the pilot country; the second five by the Federal Republic of Germany; the third five by Belgium; the next four by The Netherlands; and the next five by Denmark; and with this one, the last three by Portugal. th This volume contains the papers and posters presented at the 27 NATO/CCMS International Technical Meeting on Air Pollution Modeling and Its Application held in Banff, Canada, 24-29 October 2004. The key topics at this ITM included: Role of Atmospheric Models in Air Pollution Policy and Abatement Strategies; Integrated Regional Modeling; Effects of Climate Change on Air Quality; Aerosols as Atmospheric Contaminants; New Developments; and Model Assessment and Verification. 104 participants from North and South America, Europe, Africa and Asia attended th the 27 ITM. The conference was jointly organized by the University of Aveiro, Portugal (Pilot Country) and by The University of Calgary, Canada (Host Country). A total of 74 oral and 22 poster papers were presented during the conference.

Recent developments in air pollution modelling are explored as a series of contributions from researchers at the forefront of their field. This book on air pollution modelling and its application is focused on local, urban, regional and intercontinental modelling; data assimilation and air quality forecasting; model assessment and evaluation; aerosol transformation; the relationship between air quality and human health and the effects of climate change on air quality. It consists of a series of papers that were presented at the 30th NATO/SPS International Technical Meeting on Air Pollution Modelling and its Application held in San Francisco, U.S.A., May 18-22, 2009. It is intended as reference material for students and professors interested in air pollution modelling at the graduate level as well as researchers and professionals involved in developing and utilizing air pollution models.

Recent developments in air pollution modeling are explored as a series of contributions from researchers at the forefront of their field. This book on air quality modeling and its applications is focused on local, urban, regional and intercontinental modeling, data assimilation and air quality forecasting, model assessment and validation, aerosol transformation, the relationship between air quality and human health and the effects of climate change on air quality. It consists of a series of papers that were presented at the 28th NATO/CCMS Conference on Air Pollution Modeling and its Application held in Leipzig, Germany, May 15-19, 2006. It is intended as reference material for students and professors interested in air pollution modeling at the graduate level as well as researchers and professionals involved in developing and utilizing air pollution models. *Discusses cutting-edge developments on air pollution modeling and air quality issues *Presents topical and highly relevant subjects to the air quality and modeling research community *Provides material that can be used to further improve air quality modeling and to inform the community about recent and novel developments in the field

This volume seeks to cover the latest scientific developments in the field of air pollution modelling. It contains papers and posters presented at the Proceedings of the Twenty-Seventh NATO/CCMS International Technical Meeting on Air Pollution Modelling and Its Application, November 2004.