Proceedings of a Symposium Organized by the Commission of the European Communities, Directorate-General for Science, Research and Development, and held in Brussels from November 3--5, 1986

Are extreme weather events becoming more common? How do extreme weather events impact society? These are critical questions that must be examined as we confront the possibility that the world will experience a change in climate over the next century. Much of the research in climatology over the past decade has focused on potential changes in long- term averages of temperature, precipitation and other factors. However, it is becoming increasingly clear that changes in average values will be accompanied by changes in extreme events. Furthermore, extreme weather events will impact society to a greater extent as people around the world continue to locate in more hazard-prone areas such as coastal zones. This book represents a major step forwards in developing a comprehensive set of information about changes in extreme events by providing a review of the problems in data availability, quality and analysis that make deriving a clear picture of world-wide changes in extreme events so difficult. Audience: The book is intended for policy-makers, professionals, graduate students and others interested in learning how extreme weather events have changed, and how they impact society both now and in the future.

The CLimatoLogy Research Programme of the Commi ssion of the European Communities started in 1980 after a few years of preparation which foLLowed the concern caused by the European drought of 1976. It was mainLy a concern about European Land and water resources, which then as never before appeared threatened by cLimate vagaries. It was mainLy an economic concern which Led the Commmission to propose, and the CounciL to adopt, a five-year piLot research programme which in the meantime has proved to be both usefuL and successfuL. The best speciaLists in many interreLated fieLds were brought together for the first time to join into a unique cooperation effort in the area of European cLimatoLogicaL research. The programme aLso enjoyed the efficient and competent cooperation of an Advisory Committee for Programme Management (ACPM) which, being essentiaLLy composed of cLimatoLogists, proved to be a scientific body of high quaLity, whose work has been one of the factors for the success of the programme. The Advisory Committee shared with the Services of the Commission the responsibiLity of preparing a Review Symposium, thought to be the best means of coLLecting and presenting the resuLts of the research performed during 1980-1984. This voLume contains the proceedings of that Review Symposium of the EC CLimatoLogy Research Programme, organized by the Directorate GeneraL of Science, Research and DeveLopment jointLy with the Centre d'Etudes et de Recherches Geodynamiques et Astronomiques (CERGA) at Sophia AntipoLis, France, 2-5 October 1984.

This volume contains progress papers in atmospheric ozone research which were presen- ted at the Ouadrennial Ozone symposium held in Greece from 3 to 7 September, 1984. These pa- pers are grouped in nine chapters corresponding to the nine sessions of the symposium. The Editors proVide the following summary of the highlights for each chapter; this summary has been prepared after consulting the papers submitted for publication as well as session summa- ries kindly provided by the following session chairmen: R. Bojkov, H. DOtsch, P. Fabian, J. Hai- gh, I. Isaksen, L. Kaplan, K. KOnzi, J. London, H. Mantis, C. Mateer, A. Matthews, G. Megie and J. Russell. Chapter 1 entitled: Chemical -radiative -dynamical model calculations includes results from recent developments in modeling techniques. The chapter begins with the results from a two -dimensional model using isentropic coordinates. With prescribed diabatic heating rates and a judicious choice of eddy diffusion coefficients this method can produce realistic fields of several stratospheric species. Three dimensional model simulations come next which demon- strate ozone transport by the stationary and transient components of the flow and emphasize the role of wave transport of ozone during a sudden stratospheric warming. The problem of chemical model validation is addressed in several different approaches.

Palaeoclimatology is presently experiencing a period of rapid growth of techniques and concepts. Studies of earth's past climates ryrovide excellent opportunities to examine the interactions between the atmosrhere, oceans, cryosphere and the land surfaces. Thus, there is a growing recognition of the need of close collaboration between palaeoclimatologists and the climate mode 11 ers. The workshop "Palaeoclimatic Research and Models (PRaM)" was organized by the Directorate General for Science, Research and Development within the framework of the Climatology Research Programme of the Commission of the European Communities (CEC). The aim of the workshop was to give to the members of the Contact Group "Climate Models" and "Reconstitution of Past Climates" of the CEC Climatology Research Program~e and to some invited scientists the opportunity to discuss problems of mutual interest. About 35 experts fr.om 10 countries took nart in the workshop. In general, palaeoclimatologists were asked to identify and discuss the data corresponding to the three topics as defined by the programme committee: 1) Abrupt Climate Changes 2) Initiation of Glaciation 3) Glaciated polar regions and their impact on global climate. Climate modellers were asked to give their views as to how these specific problems could be modelled, what use could be ~ade of the available palaeoclimatic data and which complementary data are needed for modelling.