Our group has spent considerable time in the field: Duke Forest in North Carolina; multiple locations in New England; Summit, Greenland; Kathmandu, Nepal; Houston, TX; Fort Worth, TX; and Centerville, AL. The Houston work includes focused field campaigns and a longer-term project investigating health impacts of particulate matter on exposed populations (HACHE). Professor Griffin recently made a trip to Tianjin, China (July 2012) to meet collaborators and scout potential field operations. Our field instrumentation includes a high-resolution time-of-flight Aerodyne aerosol mass spectrometer, a Brechtel particle-into-liquid sampler, a TSI, Inc. scanning mobility particle sizer, and custom-built laser-based spectroscopes (in conjuntion with the MIRTHEprogram) to measure atmospheric ammonia, hydrogen peroxide, and other important trace gases. We also operate filter samplers to perform off-line analysis of particle chemical composition. Funding has been provided by the National Science Foundation, the National Oceanic and Atmospheric Administration, the Texas Commission on Environmental Quality, the Houston Endowment, the MIRTHE center, the Dreyfus Foundation, the Shell Center for Sustainability, and the Environmental Protection Agency.
Some recent discoveries include the role of less aged semi-volatile organic compounds in growth of small particles in a forested atmosphere (Ziemba et al., 2010), the conversion of nitric to nitrous acid, potentially associated with the presence of hydrocarbon materials in Houston (Ziemba et al., 2010), the lack of biomass burning signals in Houston summer aerosol (Shakya et al., 2011), the seasonal dependence of ammonia sources in Houston (Gong et al., 2011), the formation of very small particles in New England around the winter-to-spring transition (Place et al., 2010), partitioning of soluble organic gases between the atmosphere and the snowpack in Summit (Anderson et al., 2008), the predominance of motor vehicular sources in Kathmandu (Shakya et al., 2010), the relatively less oxidized nature of secondary organic aerosol in Houston summer (Cleveland et al., 2012), the presence of excess ammonia (with respect to inorganic aerosol) in Houston summer (Gong et al., 2013), and the influence of landfills on local neighborhood air quality in Houston (Jahjah et al., 2014; Stefanski et al., 2014).