Coupling the stochastic particle-resolved aerosol model PartMC-MOSAIC with WRF

 
Poster PDF

Authors

Jeffrey Henry Curtis — University of Illinois at Urbana-Champaign
Nicole Riemer — University of Illinois at Urbana-Champaign
Matthew West — University of Illinois at Urbana-Champaign

Category

Modeling

Description

Two-dimensional particle size distribution quantifying the mixing state of black carbon at 5 selected levels in the boundary layer after 12 hours of simulation (1800 LST). The results indicate that over time a complex pattern of mixing states develops and that this depends on altitude. Fresh black-carbon-containing particles (high BC mass fraction) exist only in the lowest layers.
To assess the chemical reactivity, cloud condensation nuclei (CCN) activity, radiative properties, and health impacts of black-carbon-containing particles, an understanding of the aerosol mixing state is of crucial importance. The recently developed particle-resolved aerosol box model PartMC-MOSAIC has allowed new insight into this issue, as it resolves the evolution of the per-particle composition explicitly for a particle population undergoing coagulation, condensation, dilution, and emission. So far PartMC-MOSAIC has been used as a Lagrangian box model without resolving spatial variation. The work shown in this presentation is taking the model development to a new level by coupling PartMC-MOSAIC to a one-dimensional version of the community model WRF. We will present the newly developed, particle-based stochastic algorithm for turbulent diffusion and show results of code verification. We will also show, for the first time, the results of spatial- and particle-resolved simulations of black carbon aging in a polluted boundary layer that demonstrate the capabilities of the coupled WRF-PartMC-MOSAIC model system. These initial results indicate that while the bulk concentration of black carbon becomes well-mixed in the boundary layer during the day, fresh black carbon particles exist in only the lowest layers.