We are currently studying the concentration, composition and optical properties of atmospheric aerosols in the Canadian Arctic.  We are particularly interested in light-absorbing particles such as black carbon. These species potentially contribute to climate change due to their light-absorbing properties.

This work includes:

• • Studying the formation of brown carbon in laboratory experiments that mimic reactions that occur in cloud droplets,

  • Measuring aerosol light scattering and light absorption properties in-situ at Eureka, Nunavut on Ellesmere Island,

  • Developing and applying new techniques for studying the chemical composition of aerosols that are based on Raman spectroscopy and micro-spectroscopy.

Secondary organic aerosol (SOA) is formed in the atmosphere from chemical reactions that process more volatile compounds to produce SOA.  In many regions, SOA is an important contributor to the total observed PM2.5, which is an important pollutant.   We are developing and evaluating new models for the formation and evolution of SOA and investigating if these models accurately predict the properties and concentrations of SOA measured in both Los Angeles and Alberta.  For an example of our recent work see our paper recently published in Atmospheric Chemistry and Physics.

                                                                     Organic aerosol concentrations measured downwind of the Alberta Oil Sands during Summer 2013

(Click to zoom)

Surfactants are often used during enhanced oil recovery (EOR) operations (e.g. hydraulic fracturing) in order to boost the productivity of oil and gas wells.  We are interested in how these surfactants bind to the surfaces of minerals under conditions are specific to EOR operations.  We have published this paper on the interplay between pH and ionic strength and how electrostatic forces influence the supra-molecular structure of surfactants at interfaces.

More recently, our focus has shifted to studying polymers surfaces and determining the surface structure of polymers, including functional group orientation, using sum frequency generation spectroscopy.