RUI: The Production and Degradation of Acetone in Seawater

羟基自由基是大气中最重要的氧化剂，在大气化学中起着至关重要的作用。在较干燥的对流层上层，丙酮等含氧碳氢化合物是羟基自由基的主要来源。海洋在丙酮循环进出对流层方面的作用被认为是重要的，但目前还没有得到很好的确定。更好地了解控制海洋中丙酮浓度的生产和销毁过程，最终将使科学家能够估计全球丙酮的海气通量及其对对流层化学的影响。在这个项目中，查普曼大学的研究人员将通过解决四个短期目标来研究丙酮的海-空气通量：(1)使用与本科生研究能力兼容的方法在海水中测定纳摩尔水平的丙酮；(2)在干燥和潮湿的雨季中，在南加州沿海地区的几个日间测定表层海水中的丙酮浓度；(3)估计海水中丙酮的生物和光化学产生速率；以及(4)估计海水中丙酮的光化学和生物降解率。长期目标是提高对丙酮在表层海水中的处理过程的总体了解，并最终提高丙酮在海-气界面上的通量。拟议的研究建立在PI的基础上？在分析表层海洋中产生的痕量气体和沿海水域中CDOM的光化学方面拥有丰富的经验，并将在PIS中使用现有的分析设施？查普曼的实验室。这项提议将对查普曼大学本科生的综合研究和教育体验产生重大而广泛的影响。查普曼是一所以文科为基础的小型私立大学，位于南加州一个文化多元化的社区。除了为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环境化学高级专题：大气化学、仪器分析和物理化学的PI教授的本科课程的课程和实验室，每年有10-20名化学专业的学生参加。

Hydroxyl radicals are the most important oxidants in the atmosphere, playing a critical role in atmospheric chemistry. Oxygenated hydrocarbons like acetone are a major source of hydroxyl radicals in the drier upper troposphere. The role of the oceans in cycling acetone into or out of the troposphere is believed to be important but is currently not well established. A better understanding of the production and destruction processes that control acetone concentrations in the sea would ultimately allow scientists to estimate the global air-sea flux of acetone and its impact on tropospheric chemistry. In this project, researchers at Chapman University will study the sea-air flux of acetone by addressing four short-term goals: (1) determining acetone at nanomolar levels in seawater with a method compatible with undergraduate student research capabilities; (2) determining acetone concentrations in surface seawater at coastal sites in Southern California over several diurnal periods in the dry and wet rainy season; (3) estimating the biological and photochemical production rates of acetone in seawater; and (4) estimating the photochemical and biological degradation rates for acetone in seawater. The long term goals are to improve the overall understanding of the processing of acetone in surface seawaters and ultimately the flux of acetone across the air-sea interface. The proposed research builds on the PIs? extensive previous experience in the analysis of trace gases produced in the surface ocean and the photochemistry of CDOM in coastal waters and will use existing analytical facilities in the PIs? laboratories at Chapman. This proposal will have significant broader impacts on the integrated research and educational experience of undergraduate students at Chapman University. Chapman is a small private liberal arts-based university located in a culturally diverse community in Southern California. In addition to providing significant research opportunities to undergraduate students, findings and methods from this study will be incorporated into the curriculum and laboratories of undergraduate courses taught by the PIs in Advanced Topics in Environmental Chemistry: Atmospheric Chemistry, Instrumental Analysis and Physical Chemistry, taken by 10-20 chemistry majors per year.