Goldstein group research themes include atmospheric chemistry and biogeochemistry. We investigate anthropogenic and natural contributions to the chemical composition of the troposphere, interactions of air pollution with ecosystems, aerosol composition and chemistry, and the biogeochemistry of greenhouse gases and stratospheric ozone depleting gases. A unifying theme in our research is to understand the balance between natural and anthropogenic sources of trace gases and aerosols in earth’s atmosphere, and to elucidate the biogeochemical processes which control their budgets. One of our major foci is to push the forefront of observational capabilities through the development and deployment of novel analytical instrumentation, making possible new avenues of research to address elusive scientific questions. We develop instrumentation, develop and maintain long term biosphere-atmosphere exchange experiments, engage in short term field campaigns, perform controlled laboratory experiments, and utilize models of atmospheric processes, all with the goals of understanding the composition and chemistry of earth’s atmosphere, how it functions naturally, and how it is impacted by anthropogenic emissions and changing climate.