In 1969 the North Atlantic Treaty Organization (NATO) established the Committee on Challenges of Modern Society (CCMS). The subject of air pollution was from the start, one of the priority problems under study within the framework of various pilot studies undertaken by this committee. The organization of a periodic conference dealing with air pollution modelling and its application has become one of the main activities within the pilot study relating to air pollution. These international conferences were successively organized by the United States (first five); Federal Republic of Germany (five); Belgium (five); The Netherlands (four) and Denmark (five). With this one Portugal takes over the duty. This volume contains the papers and poster abstracts presented at the NATO/CCMS International Technical Meeting on Air Pollution Modelling and Its Application held in Louvain-la-Neuve, Belgium, during 15-19 October 2001. This ITM was jointly organized by the University of Aveiro, Portugal (Pilot country) and by the Catholic University of Louvain, Belgium (host country). The ITM was attended by 78 participants representing 26 countries from Western and Eastern Europe, North and South America, Asia, Australia and Africa. The main topics of this ITM were : Role of Atmospheric Models in Air Pollution Policy and Abatement Strategies; Integrated Regional Modelling; Global and Long-Range Transport; Regional Air Pollution and Climate; New Developments; and Model Assessment and Verification.

Proceedings of the Twenty-first NATO CCMS International Technical Meeting held in Baltimore, Maryland, November 6-10, 1995

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.

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.

In 1969, the North Atlantic Treaty Organization (NATO) established the C- mittee on Challenges of Modern Society (CCMS). The subject of air pollution was from the start one of the priority problems under study within the framework of various pilot studies undertaken by this committee. The organization of a periodic conference dealing with air pollution modelling 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 fourth four by The Netherlands, the next five by Denmark and the last five by Portugal. This volume contains the abstracts of papers and posters presented at the 29th NATO/CCMS International Technical Meeting on Air Pollution Modelling and Its Application, held in Aveiro, Portugal, during September 24–28, 2007. This ITM was organized by the University of Aveiro, Portugal (Pilot Country and Host Organization). The key topics distinguished at this ITM included: Local and urban scale modelling; Regional and intercontinental modelling; Data assimilation and air quality forecasting; Model assessment and verification; Aerosols in the atmosphere; Interactions between climate change and air quality; Air quality and human health.