AAAR 32nd Annual Conference
September 30 - October 4, 2013
Oregon Convention Center
Portland, Oregon, USA
Abstract View
Regional-scale Modeling of Organic Aerosol Composition in Europe: Insights from Comparison with Aerosol Mass Spectrometer Factor Analysis
CHRISTOS FOUNTOUKIS, Athanasios Megaritis, Ksakousti Skyllakou, Panagiotis Charalampidis, Christodoulos Pilinis, Spyros Pandis, Foundation for Research & Technology, Hellas
Abstract Number: 264 Working Group: Carbonaceous Aerosols in the Atmosphere
Abstract A detailed three-dimensional regional chemical transport model (PMCAMx-2008) was applied over Europe focusing on the formation and chemical transformation of organic matter. Three periods representative of different seasons were simulated, corresponding to intensive measurement campaigns at various sites. An extensive set of AMS measurements (15 datasets in total) was used to evaluate the model and, using PMF analyzed data, gain more insight into the sources and transformation of OA, as well as identify strengths and limitations of our current OA modeling framework. Overall, the agreement between predictions and measurements for total fine OA mass is encouraging with the model reproducing more than 72% of the data within a factor of two. Oxygenated OA (OOA) is predicted to contribute 93% to total OA over Europe during May, 87% during winter and 96% during autumn with the rest comprising fresh POA. Predicted OOA concentrations show much less error compared to HOA for all periods. The errors for HOA concentrations are most likely an indication of errors in the emissions rates of OA and/or errors in their assumed volatility distribution. The measured LV-OOA mass compares well with the sum of the modeled background OA and the OOA from the lower 2 or 3 volatility bins depending on the period simulated. Biomass burning OA is most likely underestimated in the emission inventory especially during the autumn period. Sensitivity of model results to the assumed volatility distribution of emissions and the aging rate will be discussed.