Description: Das Projekt "Kernbildungsprozesse durch Oxidation biogener fluechtiger organischer Verbindungen (NUCVOC)" wird vom Umweltbundesamt gefördert und von Gesellschaft zur Förderung der Spektrochemie und Angewandten Spektroskopie, Institut für Spektrochemie und Angewandte Spektroskopie durchgeführt. Atmospheric aerosol particles affect the Earth's radiative balance both directly through backscatter of solar radiation and indirectly as cloud condensation nuclei (CCN). At present, the effects of the tropospheric aerosols are one of the largest uncertainties in quantifying climate forcing due to man-made changes in the composition of the atmosphere. The main tasks covered by NUCVOC addresses two aspects with considerable tropospheric relevance: -to evaluate the formation of aerosol quantitatively from natural sources with special emphasis on new particle formation processes, -to gain information about the organic component of the tropospheric aerosol. The overall objectives of the NUCVOC projekt can be summarized as follows: Systematic investigation of the formation of particles of selected model compounds (alpha-pinene, beta-pinene, limonene, sabinene etc) in laboratory studies (considering oxidation by NOdeep3, OH, Odeep3 reactions). Chemical analysis of the organic particle phase focusing on the very non-volatile fraction of the biogenic oxidation products. Development of the chemical mechanism describing the routes to form condensable species. Experimental verification of the nucleating abilities of certain products by A) The synthesis of a few selesignificant oxidation products. B) The determination of relevant physical parameters of these compounds (surface tension, density etc). C) The use of the thermal diffusion cloud chamber. Modelling the formation of particles (homogeneous nucleation, condensation, coagulation etc) The contribution of our group will consist of following objectives: -Measuring rates of the formation of aerosol from terpenes (model compounds) reactions with NOdeep3 radicals, using time resolved techniques. NOdeep3 radicals will be generated by flash light photolysis using suitable precursor (ie HNOdeep3) and its decay in real time will be studied using laser longpath absorption. The relation of extinction of the laser light and the particle characteristics is expected to provide information on the homogeneous nucleation rates of the oxidation products. Identification of the oxidation products of biogenic VOC reactions using a photochemical smog chamber / FTIR technique. The experimental study will be accompanied by modelling studies of the homogeneous nucleation rate of oxidation products of biogenic VOC using classical nucleation theory.
Types:
SupportProgram
Origin: /Bund/UBA/UFORDAT
Tags: Wolkenbildung ? Limonen ? Bewölkung ? Photochemischer Smog ? Terpene ? Nitrat ? Blitz ? VOC ? Laser ? Solarstrahlung ? Zellkern ? Smog ? Main ? Absorption ? Aerosol ? Chemische Analyse ? Flockung ? Photolyse ? Spektralanalyse ? Organische Verbindung ? Vorläufersubstanz ? Bilanz ? Chemikalien ? Koagulation ? Kondensation ? Oxidation ? Studie ? Troposphäre ? Modellierung ? Oberflächenspannung ? Diffusion ? Chemische Reaktion ? Kenngröße ? Kondensationskern ? Atmosphäre ? Partikel ? Bildungsrate ? Homogeneous-Nucleation ? NOdeep3-Radicals ? Aerosolentstehung ? Oxidationsprodukt ? Tropospheric-Aerosol ? Biogene-organische-Verbindung ? Biogenic-VOC ? Extinction-Measurements ? Flash-Light-Photolysis ? Gas-to-Particle-Conversion ?
Region: Nordrhein-Westfalen
Bounding box: 6.76339° .. 6.76339° x 51.21895° .. 51.21895°
License: cc-by-nc-nd/4.0
Language: Deutsch
Time ranges: 1998-01-01 - 2000-06-30
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