AAAR 31st Annual Conference
October 8-12, 2012
Hyatt Regency Minneapolis
Minneapolis, Minnesota, USA
Abstract View
Dimethylamine-Sulfuric Acid Clustering Can Explain Observed Atmospheric New Particle Formation
Ismael Kenneth Ortega Colomer, Oona Kupiainen, Tinja Olenius, Matt J. McGrath, Theo Kurten, VILLE LOUKONEN, Taina Yli-Juuti, Ilona Riipinen, Johannes Leppä, Markku Kulmala, Hanna Vehkamäki, University of Helsinki
Abstract Number: 41 Working Group: Aerosol Nucleation: From Clusters to Nanoparticles
Abstract Despite the importance of atmospheric particle formation for both climate and air quality, non-empirical models have so far been unable to reproduce atmospheric observations using realistic trace gas concentrations. We have used a kinetic cluster model, together with first principles evaporation rates, to simulate the formation rate of sulfuric acid – ammonia – dimethylamine clusters with mobility diameter 1.4-1.6 nm. We have compared the results with state-of-the-art experimental values, and have found a good agreement with the observed formation rates. The presence of trace (sub-ppt) concentrations of dimethylamine together with atmospherically realistic concentrations of sulfuric acid results in formation rates close to those observed in the atmosphere. Additionally, we have found that the effect of galactic cosmic rays on new particle formation is negligible when amines are present, though it may still play a significant role in conditions where the concentration of cluster-stabilizing trace gases such as amines is low.