NOAA Chemical Sciences Division Seminar
Aerosol Particle Organic Mass Formation: HOMs uptake, multiphase isoprene oxidation and cloud processing by Hartmut Herrmann, Leipzig Institute for Tropospheric Research (TROPOS), Germany
In the first part results from the Leipzig Aerosol Chamber (LEAK) and selected field investigations will be presented and discussed which deal with the formation of highly oxidized molecules (HOMs) from terpenes and their transfer into the particle phase. Here, investigations of ozone and OH initiation will be discussed with emphasis on particle phase analytics. Molecular mechanisms will be outlined and the potential impact of HOMs transfer on particle oxidant levels will be studied by CAPRAM modelling. In the second part, a study on the aqueous phase chemistry of dihydroxy carbonyl compounds resulting from isoprene oxidation under low NOx conditions will be given. Here, rate constants for free radical reactions have been derived and product studies have been undertaken. In the third part, the Hill-Cap Cloud Thuringia (HCCT-2010) will be described and results will be presented to characterize chemical aerosol-cloud interaction resulting in changing processed particle composition both with regards to inorganic and organic constituents. The results suggest that additionally formed organic mass during cloud processing is related to both anthropogenic emissions and the intensity of solar radiation under the campaign conditions. A summary and an outlook will be given.