Wofsy-Munger Greenhouse Gases (GHG) and Biosphere-Atmosphere Exchange Group
The chemical composition of the earth's atmosphere is changing rapidly due largely to human activities such as combustion of fossil fuel, clearing of forests, and agriculture. Global concentrations of radiatively active (greenhouse gases: CO2, CH4, N2O) are increasing. Historically, primary air pollutants (NO, CO, SO2), which also contribute to acid deposition, aerosols, and ground-level ozone have increased, though their levels are dropping in some locations where emission controls have been effective. Stratospheric ozone levels have been decreasing due to chlorine-containing gases that remain in atmosphere from their extensive use in the past. These atmospheric perturbations have potentially deleterious effects including climatic warming, regional and urban air pollution that impacts human and ecosytem health, and increased exposure to solar ultraviolet light. Quantitative information on the ambient concentrations and fluxes of important atmospheric gases is needed to foster a deeper understanding of chemical transformation rates and chemical transport dynamics in the atmosphere and identify their sources and sinks. This understanding can then be used to help make better decisions regarding the world's resources and evaluate the effectiveness of control strategies. We seek to understand how the atmosphere works as a chemical and physical system.