RUI: The production and degradation of oxygenated hydrocarbons in seawater

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Oxygenated hydrocarbons are ubiquitous in the atmosphere with levels ranging from low ppt (acetaldehyde) to low ppb (methanol). They react rapidly with hydroxyl radicals to produce ozone, carbon monoxide, and a variety of other secondary products, and they also contribute to particle formation in the atmosphere. Over the last decade, attempts have been made to inventory sources and analyze atmospheric budgets. Although estimates have improved, significant discrepancies remain. In particular, the role of the oceans as a source or sink for oxygenated hydrocarbons is one of the largest sources of uncertainty in global models. Budget estimates are limited by the very small database of ocean mixed layer measurements and a limited understanding of processes controlling levels in seawater. In this project, faculty and undergraduate students at Chapman University will continue their earlier NSF-sponsored efforts to measure the photochemical and biological production and destruction rates of 4 atmospherically-relevant oxygenated hydrocarbons (acetone, acetaldehyde, methanol and ethanol) in coastal waters. These studies will provide process level data that will better constrain the role of the oceans in cycling these species into or out of the troposphere. Broader Impacts: This project will have significant broader impacts on the research experience of undergraduate students at Chapman University, a private, liberal arts-based university with 4,500 undergraduate students located in a diverse community in Southern California with a strong commitment to undergraduate research in environmental chemistry. The PIs currently supervise the research projects of 5 undergraduates, and anticipate working with 4-6 students in summer research on this project. Students will present their research at national meetings. In addition to providing significant research opportunities to a large group of undergraduate students, findings and methods from this study will be incorporated into undergraduate courses taught by the PIs in Atmospheric, Instrumental and Physical Chemistry, expanding project impacts to a larger audience.