| Particulate matter (PM) pollution is one of the major environmental challenges the world is facing today. A significant fraction of ambient PM is derived from gas-to-particle conversion processes---known as secondary PM---from gas-phase emissions such as oxides of nitrogen and sulfur, and volatile organic compounds (VOCs). The formation of secondary PM in a given region depends on the emissions profile and atmospheric conditions (temperature, wind, relative humidity, etc.) of the region. Therefore, three-dimensional computational models are needed to gain insights on PM formation and develop strategies to mitigate particulate pollution.;The organic component of secondary PM, known as secondary organic aerosol (SOA), is formed in the atmosphere from gas-phase VOC emissions. In this dissertation, a three-dimensional model for SOA simulation is constructed and applied to the South Coast Air Basin of California (SoCAB). Model predictions show that atmospheric transport plays a significant role in SOA formation in the region. Inland areas experience high SOA levels due to transport of precursor emissions from urban coastal areas of the basin.;Similar to SOA, a non-linear relationship exists between the formation of secondary inorganic PM and precursor emissions; Therefore three-dimensional air quality models are often applied to study impacts from emission sources of interest. This dissertation presents two such studies. The UCI-CIT air quality is applied to quantify PM impacts from ship emissions in the region. Results show that ships contribute to particulate nitrate and sulfate increase up to 12.8 and 1.7 mug/m3 respectively, mostly from the secondary formation. Simulations of future year scenario shows dramatic increase of impacts from ships. After the SoCAB, San Joaquin Valley (SJV) region experiences high levels of ambient PM in California. Additional emissions may occur in the SJV from distributed generation (DG) of electricity to meet future power needs. Air quality modeling is conducted for future scenarios of DG power in the SJV. Among the DG scenarios of advanced and biomass-based technologies considered, a peak increase in PM of 0.7 mug/m3 is predicted.;Overall findings in this dissertation demonstrate the importance of atmospheric mechanisms in the production of secondary organic and inorganic PM. |
