As the regional models required to understand and control the generation, distribution and deposition of air pollutants become more precise, the need to understand the detailed effects of hilly and mountainous terrain becomes more acute. The Alpine regions and the mountainous Mediterranean coasts have large effets on the way the pollutant burden is spread in their areas. Similarly an understanding of the effects of chemical and physical processes controlling pollutant deposition and the emission of biogenic compounds is essential to the correct modelling of the coastal regions which surround so much of Europe.
The results from two projects on these problems are presented in this volume: one involved a series of field campaigns in the Alps and in the Rhine valley, the other involves ships and platforms in the North Sea and also in the Mediterranean.

I: Air - Sea Exchange.- 1 Overview of Air - Sea Exchange.- 2 Aerosols and Deposition to Marine Systems.- 2.1 A Review of the Magnitude and Significance of Atmospheric Inputs of Metals and Nutrients to Marine Ecosystems.- 2.2 The North Sea Experiment 1991 (NOSE): A Lagrangian-type experiment.- 2.3 Factors Determining Particle Dynamics over the Air-Sea Interface.- 2.4 Aerosol Dynamics Modelling in the Marine Atmospheric Surface Layer.- 2.5 Dynamics of Aerosols in the Marine Atmospheric Surface Layer.- 2.6 Fluxes in the marine atmospheric boundary layer.- 2.7 Aerosol and Rain Chemistry in the Marine Environment.- 2.8 Atmospheric Inputs to Marine Systems.- 2.9 Transformation of Polluted Air Masses when Transported over Sea with respect to Deposition Processes.- 2.10 Chemical Transformations in the North Sea Atmosphere.- 2.11 Elemental Composition and Sources of Atmospheric Aerosols above and around the North Sea.- 2.12 Study of Individual Particle Types and Heavy Metal Deposition for North Sea Aerosols using Micro and Trace Analysis Techniques.- 2.13 Air-Sea Exchange Fluxes of Mercury and Atmospheric Deposition to the North Sea.- 2.14 Deposition of Nitrogen Compounds to the Danish Coastal Waters.- 3 Biological Processes and Air-Sea Exchange of Biogases.- 3.1 Oceans as Sources or Sinks of Biologically Produced Gases Relevant to Climatic Change.- 3.2 Influence of Photochemical and Biological Processes on the Selenium Cycle at the Ocean-Atmosphere Interface.- 3.3 Biological Production of Trace Gases in Surface Seawater and their Emission to the Atmosphere.- 3.4 Origin and Importance of Particulate Dimethylsulphoniopropionate (DMSPp) in the Marine Cycle of Dimethylsulphide (DMS).- 3.5 Seasonal and Latitudinal Variations of Dimethylsulfide Emissions from the North-East AtlanticOcean.- 3.6 The Biogeochemical Cycling of Carbonyl Sulfide and Dimethyl Sulfide at the European Continental Margin.- 3.7 Air Sea Exchanges of Non-methane Hydrocarbons.- 3.8 The Oceanic Source of Light Non-methane Hydrocarbons.- 4 ASE Publications: 1988-1995.- II: The TRACT Experiment.- 5 Overview of TRACT.- 6 Data generation and Quality Assessments.- 6.1 Generation of an Emission Data Base for TRACT.- 6.2 TRACT Data Quality Assessment.- Chapter7 Modelling within TRAACT.- 7.1 Simulation of the Episode of the TRACT Measurement Campaign with the EURAD Model.- 7.2 Modelling of Transport, Mixing and Deposition of Air Pollutants over Inhomogeneous Terrain including Chemical Reactions.- 7.3 Contribution of Italian Participants to Measurements and Model Simulations.- 8 Atmospheric Processes>.- 8.1 Transport Processes over Complex Terrain.- 8.2 Balloon Air Turbulence Measurements at Hegeney.- 8.3 Surface Flux Variability in Relation to the Mesoscale.- 8.4 Investigation of Mixing Processes in the Lower Troposphere over Orographically Structured Terrain.- 9 TRACT Publications: 1988-1995.