Das Projekt "Bromkopplungschemie und ihre Auswirkungen auf den Ozongehalt der Stratosphaere" wird vom Umweltbundesamt gefördert und von Max-Planck-Institut für Chemie (Otto-Hahn-Institut) durchgeführt. There is at present considerable uncertainty in the kinetics and photochemistry of several of the key processes involved in the atmospheric bromine chemistry. Such data are needed for an improved understanding of the role of bromine in the ozone balance for the lower stratosphere. A programme of laboratory studies is proposed to provide quantitative kinetic and mechanistic data on selected gas phase, photochemical and heterogeneous reactions of bromine species. The gas phase work will cover key reactions which deplete ozone as well as those which influence the concentrations of reservoir species. Several potentially important heterogeneous reactions involving bromine reservoir species will be studied. Data for heterogeneous reactions will be brought together in a unifying physicochemical framework, which will then be used to formulate parameterizations of the reaction rates for atmospheric modeling. A preliminary assessment if the impact of the new data on atmospheric bromine and ozone depletion will be made using chemical transport models. The overall goal is to provide as complete as possible description of lower stratospheric bromine chemistry, for the purposes of modeling lower stratospheric ozone loss. Prime Contractor: University of Cambridge, Department of Chemistry; Cambridge; UK.