The "European Experiment on the Transport and Transformation of Environmentally Relevant Trace Constituents over Europe" (EUROTRAC) was established in 1986 to tackle the scientific problem and combine the expertise, knowledge and resources in Europe, in order to apply them over a large region covering the greater part of the continent. EUROTRAC is a coordinated multidisciplinary scientific research project involving field measurements, laboratory studies, instrument development and development of comprehensive computer models for the simulation of the physical and chemical processes in the lower atmosphere.

Inhalt
1.- 1.1 Highlights of the Results.- 1.2 Original Aims of the EUROTRAC Subproject HALIPP.- 2 Review of the Activities and Achievements of the EUROTRAC Subproject HALIPP.- 2.1 Introduction.- 2.2 Sulfur (IV) Oxidation by Ozone, Hydroperoxides and Hypochlorous Acid.- 2.3 Transition Metal Ions and Their Role in Atmospheric Waters.- 2.4 Photochemical Sources of Radicals in Atmospheric Water Drops.- 2.5 Free Radical Reactions in the Aqueous Phase.- 2.6 Gas-Liquid Interactions.- 2.7 Aerosol Surface Reactions and Photocatalysis.- 2.8 General Conclusions.- Individual Reports from HALIPP Contributors.- 3 Sulfur(IV) Oxidation.- 4 Transition Metal Ions in Atmospheric Waters.- 5 Photochemical Sources and Reactions of Free Radicals in the Aqueous Phase.- 6 GasLiquid Interactions.- 7 Aerosol Surface Reactions and Photocatalysis.- 8 HALIPP Publications 19881995.