Description: Das Projekt "Production and Processing of Atmospheric Aerosols from Biogenic and Biomass Burning Sources" wird vom Umweltbundesamt gefördert und von Paul Scherrer Institut durchgeführt. Aerosols affect climate through direct scattering and/or absorption of solar radiation and by acting as cloud condensation nuclei (CCN). Cloud formation and optical scattering cool the atmosphere, while optical absorption (e.g. by black carbon) warms it. These climate effects are strongly influenced by particle concentration, atmospheric lifetime, CCN activity, and optical properties, which are determined by particle composition. Composition is in turn influenced by the effects of emissions sources and oxidation-induced atmospheric transformations. Quantification of these effects has proven challenging, in part because of major uncertainties resulting from the complexity of the organic aerosol fraction. Recent studies have demonstrated the dominance and ubiquity of secondary organic aerosol (SOA), formed from atmospheric reactions of gas-phase precursors. Biogenic emissions and biomass burning constitute major sources of SOA. Biomass burning is also a major source of black carbon and primary organic aerosol. Deconvolution of aerosol sources and processes is complicated by the simultaneous influence of multiple factors on aerosol composition at field measurement sites, discrepancies between laboratory and field measurements, and limitations in existing measurement and analysis techniques. This project provides a detailed characterization of the chemical and physical properties of biogenic and biomass burning aerosol, and the rate and extent to which these properties change as a result of reaction with the OH radical, a major atmospheric oxidant. The project combines three approaches: (1) OH oxidation of model compounds and well-characterized sources characteristic of biomass burning and biogenic emissions; (2) summer and winter field measurements in locations influenced by these sources; and (3) development and deployment of a flow reactor for controlled OH oxidation of laboratory and ambient sources. Molecular tracers and/or chemical signatures for biogenic and biomass burning SOA will be identified using a newly developed coupled high-resolution time-of-flight mass spectrometer/thermal desorption aerosol gas chromatograph. The flow reactor will provide a controlled environment for ambient aerosol oxidation, thereby enabling process-level analysis of the nature and rate of molecular changes induced by atmospheric oxidation, as well as the effect of such processes on source apportionment techniques commonly applied to ambient aerosol. Optical absorption and scattering properties will be constrained with respect to atmospheric oxidation.
SupportProgram
Origin: /Bund/UBA/UFORDAT
Tags: Wolkenbildung ? Wolke ? Bewölkung ? Messstation ? Resorption ? Kohlenstoff ? Oxidationsmittel ? Skigebiet ? Solarstrahlung ? Tracer ? Brunnen ? Black Carbon ? Absorption ? Aerosol ? Sommer ? Verbrennung ? Winter ? Wirkung ? Gasförmiger Stoff ? Vorläufersubstanz ? Produktlebensdauer ? Ackerland ? Chemikalien ? Desorption ? Emission ? Oxidation ? Reaktor ? Technik ? Wirkung ? Messung ? Umwelt ? Klima ? Klimawirkung ? Kondensationskern ? Kühlung ? Partikel ? Überwinterung ? Atmosphäre ? Forschungseinrichtung ? Produktion ? BESCHREIBUNG ? GEKOPPELT ? Konzentrat ? NEU ? PROJEKT ? Radikal [Chemie] ? STANDORT ? STARK ? TEIL ? THERMISCH ? UNSTIMMIGKEIT ? Ubiquität ? ANGEWANDT ? VERARBEITEN ? VERARBEITUNG ? VERBINDUNG ? BESTEHEND ? BEZUG ? Buchgrundstück ? ENTWICKLUNG ? ERGEBNIS ? FRAKTION ? Fluss [Bewegung] ?
License: cc-by-nc-nd/4.0
Language: Deutsch
Time ranges: 2011-01-01 - 2013-12-31
Accessed 1 times.