Aerosol Sources, Transport and Sinks in Marine and Polar Regions

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Liquid and solid particles suspended in the atmosphere are called aerosol. These particles can affect climate by reducing the incoming solar radiation either directly by scattering and absorbing sunlight, or indirectly by forming clouds, which can efficiently reflect incoming sunlight. Aerosol particles can also contribute to smog, which negatively affects air quality by reducing visibility and increasing health risks that lead to earlier mortality. Finally, organic contaminants such as dioxins can absorb to the surface of aerosol particles. This represent an important transport mechanism for these chemicals from the atmosphere to the surface, both water and land. Therefore, understanding the sources, transport and loss processes of aerosol in the atmosphere is vital in order to better characterize all of these effects. The overall goal of this work is to study these aerosol processes in the atmosphere in order to accurately capture their life cycle in global climate models. In particular, this research will focus on processes occurring in marine and polar environments. With the world’s longest coastline and a vested interest in the north, the results from this research will be of timely relevance to Canadians. Specific projects will study marine fog events to investigate the process of droplet formation, aqueous chemical reactions and the influence of marine aerosol on droplet formation. Measurements of real-time chemical and physical properties will be made of the aerosol particles and fog droplets in order to elucidate the mechanisms that cause particles to form droplets. These findings will be applicable to predicting visibility of coastal fog events and can be extrapolated to the formation of prevalent stratiform clouds that cover much of the ocean. In addition, aerosol particle chemical composition in the high Arctic will be studied and used to understand their sources and transport to the Arctic throughout the year using a real-time aerosol mass spectrometer. This will serve as an important baseline as industrial activity increases in the coming decades and the chemical composition of the Arctic air changes. The results from this work will be highly relevant to regulatory agencies that work to ensure that the health of the local population and environment of the Arctic are not negatively affected. Students will work with state-of-the-art aerosol equipment and benefit from cross-disciplinary interactions. They will also benefit from conducting research in the field that will be complemented by either laboratory experiments or computer simulations in order to broaden their approach to research. In addition, the students will profit from collaborations with other departments, universities and government agencies that will extend their network and exposure to research at different levels in Canada.