Impact on Ontario’s Air Quality due to Changes in North American Emission from 2005 to 2020
This paper shows the effects of emission reductions from 2005 to 2020 levels on ozone and PM2.5 concentrations in Ontario based on modelling results. To assess the effect of these changes on Ontario’s air quality, the modelling system WRF – SMOKE – CMAQ was run with 2010 meteorology for the entire year. Emission estimates were based on US EPA Cross-State Air Pollution Rule Final CAP – BAFM 2005-Based Platform, version 4.2, Toxic rule 2016 with updates projected to 2020 for mobile emissions and Environment Canada 2005 and 2020 emission inventories.
Emission changes in Ontario and in the neighbouring US states (Ohio, Michigan, Indiana, etc.) from 2005 levels to projected values of 2020 are discussed. Modelling results were summarized to show spatial and temporal variability in ozone and PM2.5 concentration over Ontario due to emission reduction in the whole domain. Analysis was performed on annual values and on values obtained on days with high concentrations only.