Séminaire

Pr. Hendrik Fuchs, du Forschungzentrum Jülich fera un séminaire au CERLA à 10:30 "Unravel Atmospheric Chemical Mechanisms: From Laboratory to Simulation Chamber Studies"

Understanding chemical mechanisms is crucial for accurately representing reaction kinetics in chemical transport models used to predict air quality. This study will present the fundamental reactions of the hydroxyl radical (OH), using a flow tube and direct detection of time-resolved OH decay by laser-induced fluorescence. This type of experiment also enables the temperature dependence of the rate coefficients of unimolecular hydrogen shift reactions of organic peroxy radicals (RO₂) from OH reactions with organic compounds (aldehydes) to be determined, provided that OH is regenerated. Experiments investigating the night-time oxidation of isoprene were carried out in the large outdoor simulation chamber SAPHIR at Forschungszentrum Jülich to study complex reaction mechanisms. The results show that reactions involving nitrate RO₂ radicals can lead to the formation of hydroperoxyaldehydes (HPALDs), which had only been attributed to daytime oxidation, as well as epoxides, which could enhance the formation of secondary organic aerosol.