AAAR 31st Annual Conference
October 8-12, 2012
Hyatt Regency Minneapolis
Minneapolis, Minnesota, USA
Abstract View
Validation of the Particle-Resolved Aerosol Model PartMC With Data from Chamber Experiments
JIAN TIAN, Nicole Riemer, Benjamin T. Brem, Tami Bond, Mark Rood, Martin Schnaiter, Karl-Heinz Naumann, University of Illinois at Urbana-Champaign
Abstract Number: 389 Working Group: Aerosol Physics
Abstract The stochastic particle-resolved aerosol model PartMC is a recently developed aerosol model that explicitly resolves and tracks the size and composition of individual particles as they undergo transformations by coagulation and condensation in the atmosphere. This approach spreads the initial aerosol size distribution over a finite number of Monte Carlo particles and allows them to evolve using the appropriate probabilities for coagulation and other processes.
We adapted PartMC for this study from the original Lagrangian parcel model to be able to represent the aerosol evolution in an aerosol chamber, with the intention to use the model as a tool to interpret and guide chamber experiments in the future. For this purpose we added chamber-specific processes such as wall losses due to diffusion and sedimentation, and dilution effects due to sampling using the approach by Naumann (2003).
We then validated the model by comparing with data from two different aerosol chambers. First was the AIDA chamber at the Karlsruhe Institute of Technology, Germany, from which we used a multi-hour data set of coagulating fractal soot particles. For this purpose the model was also extended with a treatment of fractal-like agglomerates. Second was the mixing chamber at the Department of Civil and Environmental Engineering at the University of Illinois, where we obtained several data sets of coagulation experiments using ammonium sulfate particles and succinic acid particles. We present validation results for both the particle number concentration and aerosol size distributions in the two chambers.