University of California, Berkeley
Universidad Nacional Autonoma de Mexico
Our research group is concerned with the chemistry of the atmosphere and with the various ways in which human society can affect it. Our goal is to understand at a fundamental level the key atmospheric chemical processes that have important consequences, so that we can make reliable predictions of future changes. Our research involves laboratory studies of atmospheric chemical processes. We are also exploring science-policy issues related to urban and regional air pollution and to global change.
Gas Phase Chemical Kinetics and Photochemistry
We employ flow-tube techniques to measure elementary reaction rate constants and photochemical parameters. We monitor directly the concentrations of reactants and products, including transients, using chemical ionization mass spectrometry, laser-induced or vacuum-UV resonance fluorescence, Fourier-transform infrared spectroscopy, etc. The reactions under study involve species such as ClO , OH , HO 2 , SO 3 , etc.
Chemistry of Atmospheric Aerosols
We are studying the chemistry and the microphysics of a variety of atmospheric aerosols. We are investigating tropospheric processes involving organic and marine aerosols. We are developing new techniques to study chemical processes occurring on particle surfaces using tools such as mass spectrometry, Fourier-transform infrared and Raman spectroscopy. We are pursuing a systematic program to elucidate the nature and the mechanism of these reactions at a molecular level. In addition, we employ techniques such as differential scanning calorimetry and optical microscopy to investigate nucleation probabilities and to elucidate the mechanism of formation of cloud particles and of their interaction with anthropogenic aerosols.
Air Pollution in Megacities of the Developing World
We are developing methods to conduct integrated assessments of complex environmental problems facing major cities, particularly in the developing the world, in collaboration with the Mari Molina Center for Strategic Studies in Energy and the Environment, located in Mexico City. These assessments bring economic, risk, and policy analysis into play along with the scientific research and data that serve as the underpinnings of policy formation. The approach is dynamic, iterative, and educational, and aimed at improving both the process and the institutional capacity for environmental decision making. Regional transportation planning, health and economic impacts of air pollution, and industrial policy are examples of the fields whose knowledge are being integrated in order to address the root causes of air pollution and devise successful long-term strategies to protect human health. The assessments also integrate the analysis of urban, regional, and global air pollution and climate change-related issues that are typically addressed separately by different levels of government but which would benefit greatly by a more holistic approach.