Integrated Regional Modelling: Experimental and Numerical Study of High Ozone Events in the Alpine Region; J. Graf, et al. Global and Longrange Transport: A Three Dimensional Hemispheric Air Pollution Model Used for the Arctic; J. Christensen. New Developments: A Fast Lagrangian Particle Model for Use with Three-dimensional Mesoscale Models; W. Physick, P. Hurley. Accidental Release: A Mesoscale Boundary Layer Meteorological Model for Inhomogeneous Terrain; S.M. Daggupaty, et al. Model Assessment and Verification: Improving the Science of Regulatory Dispersion Models for Shortrange Applications; J.C. Weil. Video Session: Designing an Air Quality Network for Brisbane Using a Mesoscale Model; W. Physick, et al. Poster Session: Vertical Diffusion Parameter in the Atmospheric Boundary Layer; L.E. Venegas. Special Session: Athenian Photochemical Smog Intercomparison of Simulations (APSIS). Special Session: Air Pollution Transport and Diffusion over Coastal Urban Areas (Athens). 94 additional articles. Index.

Role of Atmospheric Models in Air Pollution Policy and Abatement Strategies: Multipollutant Modeling and Policy: Dressing the Emperor and Avoiding False Paradigms; R.L. Dennis. Meteorological Aspects of Ozone Episodes in Southern Ontario: A Mesoscale Model Investigation; R.S. Tangirala. Integrated Regional Modeling: Meteorological Modeling in Sydney, Australia: Case Study of Smog Event; P.J. Hurley, et al. Lake Breezes and Their Impact on Groundlevel Ozone Transport over Southwestern Ontario and Southeastern Michigan; D.M.L. Sills, P.A. Taylor. Global and Longrange Transport: Sulfur Deposition in Asia: An Assessment of the Present Situation and Future Scenarios; G.R. Carmichael, R.L. Arndt. The European Long Range Tracer Experiment (ETEX): Preliminary Evaluation of Model Intercomparison Exercise; G. Archer, et al. New Developments: Mesoscale Modeling of Clouds and Aerosol Particles; A.I. Flossmann. Accidental Releases: Validation of a Combination of Two Models for Longrange Tracer Simulations; J. Brandt, et al. Model Assessment and Verification: Air Pollution in Coastal Cities; D.G. Steyn. Poster Session: Use of the UB/NMC Model for the Simulation of the Lifecycle of Chernobyl Radioactive Cloud; M. Dacic, B. Telenta. 74 additional articles. Index.

In 1969 the North Atlantic Treaty Organization (NATO) cstablishcd thc Committee on Challenges of Modern Society (CCMS). The subject of air pollution was from the thc very beginning one of the priority problems umier deliberation within the tJ-amcwork of various pi- lot studies undertaken by this committee. The organization of a yearly conference dealing with air pollution modelling and its application has become one of the main activities within thc pilot study rclating to air pollution. Pleasc see the listing on the next page for completed NATO/CCMS Pilot Studies and the International Technical Meetings (ITM) on Air Pollution Modelling and Its Application. This volume contains the papers at the 22ND lTM, being held in Clermont-Ferrand, France during June 2 -6,1997. It was attended by 152 participants representing 33 countries. This lTM wasjointly organized by the Ris0 National Laboratory of Denmark (pilot country): the Laboratoire Associe de Meteorologic Physique, associated with the Centre National de la Recherche Scientifique, the Universite Blaise Pascal. and the Observatoire de Physique du Globe de Clermont-Ferrand, France (host country). We wish to express our gratitude to the sponsors that made this conference possible. In addition to tinancial support from NATO/CCMS, the conference received contributions from Centre National de Recherche Scientitique, Observatoire de Physique du Globe de Clermont-Ferrand, Universite Blaise Pascal, Electricite de France, lnstitut Francais du Pe- trole, Conscil Regional d'Auvergne, Conseil General du Puy de DC1I11e, Mairie de Clermont- Ferrand, SATCAR Semaine des arts techniques et culture de l'automobile et de la route.

In 1969 the North Atlantic Treaty Organization (NATO) cstablishcd thc Committee on Challenges of Modern Society (CCMS). The subject of air pollution was from the thc very beginning one of the priority problems umier deliberation within the tJ-amcwork of various pi- lot studies undertaken by this committee. The organization of a yearly conference dealing with air pollution modelling and its application has become one of the main activities within thc pilot study rclating to air pollution. Pleasc see the listing on the next page for completed NATO/CCMS Pilot Studies and the International Technical Meetings (ITM) on Air Pollution Modelling and Its Application. This volume contains the papers at the 22ND lTM, being held in Clermont-Ferrand, France during June 2 -6,1997. It was attended by 152 participants representing 33 countries. This lTM wasjointly organized by the Ris0 National Laboratory of Denmark (pilot country): the Laboratoire Associe de Meteorologic Physique, associated with the Centre National de la Recherche Scientifique, the Universite Blaise Pascal. and the Observatoire de Physique du Globe de Clermont-Ferrand, France (host country). We wish to express our gratitude to the sponsors that made this conference possible. In addition to tinancial support from NATO/CCMS, the conference received contributions from Centre National de Recherche Scientitique, Observatoire de Physique du Globe de Clermont-Ferrand, Universite Blaise Pascal, Electricite de France, lnstitut Francais du Pe- trole, Conscil Regional d'Auvergne, Conseil General du Puy de DC1I11e, Mairie de Clermont- Ferrand, SATCAR Semaine des arts techniques et culture de l'automobile et de la route.

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.

In 1969 the North Atlantic Treaty Organization (NATO) established the Committee on Chal- lenges of Modern Society (CCMS). The subject of air pollution was from t,lw start one of the priority problems under study within the framework of various pilot. studi('s 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 ~tudy relatillg to air pollution. The first five international conferences were organized by the United Statcs as the pilot country; the second five by the Federal Republic of Germany: thc third five by sselgium; the next four by The Netherlands; ami the two most recent by Delllllark. This volume contains the papers presented at the 21st NATOjCCMS International Technical Meeting (ITM) on Air Pollution Modelling and Its Application, held in ssaltimorc. Maryland, during November 6-10, 1995. This ITM was jointly organized by the Riso National Laboratory of Denmark (Pilot Country); by the EPA National Exposurp Research Labora- tory, United States (Host Country); and by thc American MNeorologiea.! Soci('t.: *. Cnited States (Host Organization). The ITM was attended by 137 participants representing 29 countri('~ from North and South America, Europe, Asia and Australia. The members of t.hc NATO/CCMS Scientific Committee for the 21st ITM were R.M. van Aalst (The Nethcrlallds), D. Allfossi (Haly), C. Borrego (Portugal), N. Chaumerliac (Francc), H. van Dop (Thc :\Tethcrla.nds). S.-E. Gryning.

The ITM conference series has always had a strong spirit of cooperation under the NATO/CCMS umbrella, and with the considerable interest fram Partner countries to participate in the ITM conferences, it provides an excellent opportunity to create ties between scientists. Whereas all previous ITM conferences have taken place in NATO countries, the 23rd ITM takes place in a Cooperative Partner country, Bulgaria, and is hosted by the National Institute of Meteorology and Hydrology, Bulgarian Academy of Sciences. This fact reflects a general wish for a closer connection and collaboration among scientists fram Partner and NATO countries. This volume contains the papers from the 23rd NATO/CCMS International Technical Meetings on Air Pollution Modelling and Its Application, being held September 28 - October 2, 1998, at Riviera Holiday Club, Varna, Bulgaria. It was attended by 120 participants from 30 countries. Thanks are due to all who made it possible to plan, carry through, and follow up the meeting, and to the participants who made the conference so successful. Special thanks are due to the sponsoring institutions: ATO/CCMS EURASAP RIS0 BAS 3M NATO/CCMS - Committee on the Challenges of Modem Society EURASAP - European Association for the Science of Air Pollution RIS0 - Ris0 National Laboratory, Denmark NIMH - National Institute of Meteorology and Hydralogy, Bulgaria BAS - Bulgarian Academy of Sciences 3M Representation office, Bulgaria Prestige Business Ltd. , Bulgaria The excellent collaboration with CIM (Company for International Meetings Ltd.