Size distributions of aerosol number, mass, and chemical species from the Study of Winter Air Pollution in Toronto (SWAPIT)

The Study of Winter Air Pollution in Toronto (SWAPIT) aims to better understand the whole air pollutant mixture and its spatial variability within a major urban area. Particulate matter continues to rank highly among pollutants of concern due to its association with adverse health impacts. Though aerosols across the atmospheric size range pose concerns, in situ aerosol characterization is often limited to fine particulate matter (PM2.5) and submicron particles (PM1). This has created an information gap regarding coarse particles (PM > 2.5 um) that are associated with human health impacts after inhalation as well as ecosystem impacts after atmospheric deposition.
Measurements conducted during SWAPIT determined the aerosol size distributions of particle number and mass along with chemical constituents such as elemental and organic carbon at three urban locations. Results of the measurements will be presented in the context of understanding their spatiotemporal variability and their relation to relevant sources. Comparisons to predictions using Environment and Climate Change Canada’s chemical transport model, GEM-MACH, will also be presented to evaluate model performance and to identify potential improvements to the model’s process representations.