Research

Aerosols

My research group studied aerosols associated with mining activity such as wind-blown dust from mine tailings impoundments and smelting process emissions.  We operate aerosol sampling equipment including MOUDIs and an SMPS analyzer at two field sites contaminated with arsenic and lead: the Iron King mine tailings near Dewey-Humboldt, Arizona; and the ASARCO copper mine and smelter in Hayden, Arizona (Journal of Water Air and Soil Pollution, 221, 145-157, 2011).

Pollution Prevention

I also served as PI on an EPA Pollution Prevention (P2) grant.  Together with a local non-profit, the Sonora Environmental Research Institute (SERI), we monitored metals in PM10 samples obtained in the south side of Tucson, and trained promotoras (community health workers) to visit small businesses and to encourage them to lower emissions of air toxics, and to reduce water use.

Solar Energy

We developed forecasting capability for direct normal solar insolation using the Weather Research Forecast model; and we are examining the effects of atmospheric aerosols on solar radiation received at the surface using a high-resolution spectrophotometer to make daily observations.  Work on a solar concentrator/photovoltaic array was completed in 2010.  A 2-m diameter mirror was assembled, fitted to a solar tracker, and installed and tested at a Raytheon facility near the airport.  The project was largely supported by Science Foundation Arizona.

Air Quality

There is great interest in better understanding the factors affecting air quality in the Great Lakes region because of the long, ongoing history of ozone exceedances in this densely populated part of the country.  We analyzed airplane data acquired during the 10-year LADCO project to address some fundamental questions such as: What are the concentrations and diurnal patterns of ozone and ozone precursor compounds over the lake; and is ozone formation over Lake Michigan VOC-limited or NOx-limited?

Since 2019, my group in Tucson has analyzed over ten thousand air samples for volatile organic carbon compounds which are precursors for ozone formation: University of Arizona VOC-NOx Presentation 2021 Minutes. https://webcms.pima.gov/cms/One.aspx?portalId=169&pageId=64905