Research Interests: Quantification of the effects of human activity on the composition of Earth’s atmosphere by the development of computer models used to analyze a wide variety of observations. Focus on climate change, stratospheric ozone depletion and recovery, air quality, climate change, and the global carbon cycle. Participant in numerous atmospheric chemistry field campaigns and Earth Observing Satellite missions, including the current Dynamics and Chemistry of the Summer Stratosphere (DCOTSS) aircraft campaign and the on-going FLAGG-MD effort to quantify the fluxes of atmospheric greenhouse gases in Maryland and nearby regions.