My research addresses the role of trace gases and aerosols on Earth's climate, atmospheric oxidation, and air quality. We develop instruments for fast-response in situ measurements from the ground, balloons, and aircraft.  We have participated in  more than  50 field campaigns over three decades to examine topics such as stratospheric ozone depletion over the Arctic, the impact of rockets on stratospheric chemistry, long-range transport of pollutants, and the role of aerosols in modification of cloud properties. In addition to many sites throughout the continental United States, we have conducted work in Antarctica, Spitsbergen, New Zealand, Mexico, Sweden, the U.S. Virgin Islands, Alaska, and Hawaii.  For more details, see
Google Scholar,, and ResearchGate. After shuffling between a half-dozen temporary labs on and off campus since 1999, we moved into a permanent lab at the new Sustainability, Energy, and Environment Complex (SEEC) on East Campus in March of this year. We recently completed a series of successful measurements of cloud water contents from the NCAR Gulfstream-V on the ORCAS field campaign, and on the NASA DC-8 on the KORUS-AQ campaign based in South Korea. We have proposals pending to  participate in campaigns based in Broomfield CO (February-March 2017), Hobart, Tasmania (January-February 2018), and Boise, ID (August 2018) to study properties of clouds and aerosols.

I have been teaching in the classroom since 1980, when I was instructor for a laboratory class in experimental physics for non-science majors. Since then, I have taught 25 different courses in fields ranging from fundamental physics to global ecology. Many of these courses were developed and taught for the first time.
I am currently teaching "ATOC 5151: Atmospheric Chemistry"

I am involved in various activities at CU and in the scientific community. I currently serve as the faculty director
of the Sustainability and Social Innovation Residential Academic Program (SSI RAP) located at William Village North,
the first LEED platinum residence hall at CU Boulder.

Science Policy

In 2011-2012, I served as a Jefferson Science Fellow at the U.S. Department of State in the Bureau of East Asian and Pacific Affairs, working on issues related to energy and green growth for APEC,
some of which were later included in the President's Climate Action Plan. I organized a high-level meeting on Open Governance and Economic Growth, chaired by Secretary of State Hillary Clinton, served as a delegate for the United States at the 10th APEC Energy Ministerial Meeting in St. Petersburg, Russia, and organized a workshop on Climate Change Adaptation in Singapore. Since returning to CU, I have helped developed proposals for hosting a hub of the Future Earth Secretariat in the United States and for linking educators and researchers at CU working in the fields
of sustainability and global development.

Photo: 2011 Jefferson Science Fellows with Secretary Clinton
Read: 2014 Jefferson Science Fellowship brochure
Read:  My Year as a Jefferson Science Fellow
Watch: Understanding Climate Change and the Redistribution of Heat, Winds, Water, and Worries (U.S. Center, Doha Conference, November 2012) 
The Canary in the Coal Mine: Why the Stratosphere is Still Relevant (U.S. Dept. of State, April 2012)

This page was last updated August 29, 2016