RUI: The production and degradation of oxygenated hydrocarbons in seawater

含氧碳氢化合物在大气中普遍存在，其含量从低ppb(乙醛)到低ppb(甲醇)不等。它们与羟基自由基迅速反应，产生臭氧、一氧化碳和其他各种次生产物，也有助于大气中颗粒物的形成。在过去的十年里，人们试图清点资源和分析大气预算。尽管估计有所改善，但仍存在重大差异。特别是，海洋作为含氧碳氢化合物的源或汇的作用是全球模型中最大的不确定性来源之一。由于海洋混合层测量数据库非常小，而且对控制海水水平的过程了解有限，预算估计数受到限制。在这个项目中，查普曼大学的教职员工和本科生将继续他们早先由NSF赞助的工作，测量沿海水域中与大气相关的4种含氧碳氢化合物(丙酮、乙醛、甲醇和乙醇)的光化学和生物生产和破坏率。这些研究将提供过程级别的数据，从而更好地限制海洋在将这些物种循环进出对流层方面的作用。更广泛的影响：这个项目将对查普曼大学本科生的研究体验产生重大而广泛的影响，查普曼大学是一所私立的文科大学，拥有4500名本科生，位于南加州的一个多元化社区，坚定地致力于环境化学的本科生研究。PIs目前指导5名本科生的研究项目，并预计与4-6名学生一起进行暑期研究。学生们将在全国会议上展示他们的研究成果。除了为一大批本科生提供重要的研究机会外，这项研究的结果和方法将被纳入由个人投资促进机构教授的大气、仪器和物理化学本科课程，扩大项目对更多受众的影响。

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.