Description: Das Projekt "Halogene in der marinen Umwelt - Laboruntersuchungen der heterogenen Chemie" wird vom Umweltbundesamt gefördert und von Max-Planck-Institut für Chemie (Otto-Hahn-Institut) durchgeführt. The project HAMLET is devoted to laboratory studies of the heterogeneous chemistry taking place in or at the surface of sea-salt aerosols and also ice. The experiments are designed to give insight into the mechanism of the liberation of reactive halogen from sea-salt aerosol, and into the catalytic chemical cycling schemes that sustain the concentrations of reactive halogens that have been observed in the field. The objectives of the project are therefore to gather highest quality experimental data that will allow the rate and mechanism of reactive halogen generation in the remote, polluted and polar marine boundary layer to be quantified, to assess the role of halogens in affecting the oxidizing capacity of the troposphere and to explain episodal, halogen mediated ozone destruction in the polar troposphere. Using a combination of the presently most advanced (and complementary) techniques in atmospheric heterogeneous chemistry we will investigate reactions on bulk solutions, ice surfaces, deliquescent and humidified aerosols, dry and humidified bulk surfaces and droplets. The heterogeneous techniques to be employed are: wetted-wall flow tube reactor, droplet-train reactor, Knudsen reactor, coated-wall flow tube reactor, aerosol smog chamber and aerosol-flow tube reactor. The project will: 1) Obtain data for halogen oxyacids reactions with halide ions as cycling reactions for bromine and chlorine, 2) Determine the influence of sulphate on activation and cycling of halogens from sea-salt, 3) Quantify the halogen activation potential of some NOx species, 4) Assess the role of iodine in ozone depletion and modification of liquid-phase halogen chemistry, 5) Examine the role of efficiency of uptake of several radicals species as direct and indirect oxidizing agents of bromide, 6) Involve a variety of surfaces to ensure closure on a physico-chemical description of the reactions, and to mimic the situation in the atmosphere
SupportProgram
Origin: /Bund/UBA/UFORDAT
Tags: Ozon ? Brom ? Bromid ? Chlor ? Iod ? Sulfat ? Halogen ? Halogenid ? Katalysator ? Oxidationsmittel ? Smog ? Aerosol ? Eis ? Marines Ökosystem ? Stickoxide ? U-Bahn ? Chemikalien ? Daten ? Ionen ? Oxidation ? Reaktor ? Studie ? Troposphäre ? Polargebiet ? Atmosphäre ? Atmosphärenchemie ? Chemische Reaktion ? Grenzschicht ? Ozonabbau ? Reaktionskinetik ? Laboruntersuchung ? Meersalz ?
Region: Rheinland-Pfalz
Bounding boxes: 7.5° .. 7.5° x 49.66667° .. 49.66667°
License: cc-by-nc-nd/4.0
Language: Deutsch
Time ranges: 1997-10-01 - 1999-09-30
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