The chemistry of condensed-phase materials has direct connections to issues in outdoor air quality, climate and the indoor environment. These substrates, present as either particles or films, can be oxidized by gas-phase oxidants, become photochemically altered, and participate in partitioning processes with the overlying atmosphere. In the case of particles, aerosols can act as the sites for cloud formation and have deleterious effects on human health.
Particular attention is paid to studying these processes under conditions as close as possible to those in the environment, taking advantage of a range of on-line analytical tools, many of which are mass spectrometric. Examples of instrumentation includes the use of aerosol mass spectrometry (AMS), chemical ionization mass spectrometry (CIMS), proton-transfer-reaction mass spectrometry (PTR-MS) and direct analysis in real-time mass spectrometry (DART-MS).
We are interested in the role that aerosol particles play in both liquid water (i.e. acting as cloud condensation nuclei, or CCN) and ice cloud formation (i.e. acting as ice nuclei, IN). Recent projects in this area involve field measurements of both the CCN and IN numbers in a coastal setting on the west coast of Vancouver Island. The questions we are investigating, now also in the lab, are the roles that particles from the organic microlayer present on the surface of the ocean may play as CCN and IN. As well, we have continuing projects on the nature of deposition nucleation (i.e. condensation from the gas to the particles to form ice) that occurs in the atmosphere on a wide range of substrates. These measurements are made with both home-built and commercial diffusion cloud chambers.
NETCARE (the Network on Climate and Aerosols: Addressing Key Uncertainties in Remote Canadian Environments) is a large NSERC-funded network investigating the roles of aerosol particles in clouds and climate. Jon is the Principal Investigator of the network, which brings together investigators from across Canada and from international groups as well. Please take a look at the NETCARE website for more details. The NETCARE research projects that students and postdocs in the Abbatt group are performing involve aircraft aerosol measurements in the Arctic, gas and aerosol measurements from the Amundsen icebreaker, and snow chemical characterization from Alert, Nunavut. We are particularly interested in the sources and sinks of black carbon to the Arctic and the sources of natural Arctic aerosol, such as from oceanic emissions.
Distinct from NETCARE are recent field campaigns in Toronto and at the Oil Sands where our focus was on better characterization of the sources of different carbonaceous aerosols, including black carbon.
In a new research direction promoted by the Alfred P. Sloan Foundation, we are applying techniques we have developed to study the multiphase chemistry in outdoor environments to the study of the indoor environment as well. Our initial focus has been on characterizing the nature of gas-surface reactions that occur indoors, exploring reaction kinetics, products and mechanisms. Reaction systems have included PAHs and skin oils. Of particular interest is establishing the most important oxidants of surface materials indoors and the role that substrate phase and moisture content play in driving the chemistry.