Preface. Acknowledgements. List of Lecturers. List of Participants. Developments in tropospheric chemistry; P.J. Crutzen. 3-D tropospheric model development: Impact of non methane hydrocarbon chemistry; M. Kanakidou. Model analysis of stratosphere-troposphere exchange of ozone and its role in the tropospheric ozone budget; G.J. Roelofs, J. Lelieveld. Peroxy radicals concentration and ozone generation rate for different regions of Russia as a result of TROICA-2 experiment; N.F. Elansky, et al. overview of concepts and results of the PAUR and PAUR II Projects (Modulation of Solar Ultraviolet Radiation and Photochemistry by Stratospheric Ozone, aerosols and tropospheric ozone); K.A. Kourtidis, et al. Global impact of aircraft emission on ozone concentrations and methane lifetime: Results from the 1999 IPCC aircraft assessment; I.S.A. Isaksen. The impact of NO x and H2O emissions from future Sub- and Supersonic aircraft upon the chemical composition of the atmosphere (A model study using a stratospheric CTM); M. Gauss, I.S.A. Isaksen. Calculations of radiative forcing from ozone change; F. Stordal. Atmospheric ozone as a climate gas: Studies concerning aircraft emissions; W.C. Wang, et al. Tropospheric aerosol formation: Processes observations and simulations; R.P. Turco, F. Yu. Background levels of atmospheric particulate matter over the Northeast Atlantic ocean; A.F. Rodrigues, et al. The effect of aerosol on UV flux at the Earth's surface; S. Rapsomanikis. A simplified spectral model for UV irradiance computations; F.R.S. Carvalho. Observed long-term ozone and UV changes; C.S. Zerefos. Variability of daily and annual cycles of mean erythemal solar irradiance related to total ozone variability; M. Dubrovsky. UV irradiance patterns in Italy; D. Meloni, et al. Calibration and characterization of erythemal broadband detectors; A.F. Bais. Chemistry and radiation changes in the ozone layer `Halogenated hydrocarbons (halocarbons) and their impact on stratospheric zone'; P. Fabian. Springtime stratospheric ozone over Marambio, Antarctic during 1990-1998. (Analysis of ozone sonde data in relation to the phase and position of polar vortex); J.A. Karhu, et al. Stratospheric CLO across the edge of the Arctic polar vortex: Measurements of the Airborne-Submillimeter SIS Radiometer compared to 3-D model calculations; J. Urban, et al. Vertical profiles of long lived trace gases. (A basis for the analysis of stratospheric dynamics); M. Muller, et al. Study of the Arctic polar vortex erosion from ozone Lidar measurements performed at OHP (44N, 6E); M. Marchand. APE-GAIA Airborn Polar Experiment -- Geophysica Aircraft in Antarctica; U. Cortesi, B. Carli. Heterogeneous processes in the atmosphere; G.K. Moortgat. Kinetics and mechanism of homogeneous reactions of halomethanes with chlorine atoms; P. Papagiannakopoulos. NASA's experience in deriving total ozone from satellites; P.K. Bhartia. Satellite observations of tropospheric and stratospheric gases; J.P. Burrows, et al. Monte Carlo simulations of radiative transfer for LIMB scan measurements; L. Oikarinen. Performances of the near real time code for MIPAS data analysis; P. Raspollini, et al. Aerosol retrieval algorithm for satellite solar occulation and infrared emission measurements: Theory and 3-D analysis; J.J. Bauman, P.B. Russell. An `intermediate' general circulation model for ozone change studies; S.M. Rosier, et al. Numerical study of possible influence of longitudinal ozone inhomogeneities on dynamics of the middle atmosphere; P.N. Vargin. Investigation on different total ozone time scale components; G.R. Casale, et al. Index.