Field Measurements of Trace Gas Reactions at the Air-Ocean Interface

该项目的重点是从海洋表面排放反应性气体。众所周知，海洋浮游植物和细菌会产生大量的活性气体，然后排放到大气中。最近的实验室实验表明，海洋表面的化学反应和光化学反应也可能产生大量的活性气体。该项目旨在确定各种反应性气体从海到空气的排放速率，以及这些分子在海水中的主要产生机制。这项研究将为海洋反应气体排放对氧化剂浓度和二次有机气溶胶颗粒产生速率的影响提供新的、定量的见解。这项研究的具体目标是：(1)测量含氧挥发性有机化合物(OVOCs)的海气通量，(2)利用现场测量收集的海水中的OVOC排放速率，将观测到的通量在生化、光化学和非均相反应途径之间进行划分，以及(3)确定控制OVOC在海-气界面产生的排放速率和产生途径的因素。为了实现这些目标，我们将通过涡旋协方差对海洋和大气中的挥发性有机化合物和臭氧的通量进行新的测量，同时通过流动反应堆测量从收集的海水中收集的挥发性有机化合物排放随光照强度和氧化剂暴露的函数。这里的工作将构成威斯康星大学麦迪逊分校两名化学研究生的博士论文的大部分。实地考察的内容将作为威斯康星大学麦迪逊分校多个本科生独立研究项目的基础。该项目还将允许首席调查员(PI)和博士生继续参与将小型传感器技术带到威斯康星州各地高中课堂的教育和推广活动。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

This project focuses on the emission of reactive gases from the surface of the ocean. It is well known that marine phytoplankton and bacteria produce a wide array of reactive gases that are subsequently emitted to the atmosphere. Recent laboratory experiments have suggested that chemical and photochemical reactions at the surface of the ocean may also produce significant quantities of reactive gases. This project is designed to determine both the sea-to-air emission rate of a wide array of reactive gases and the dominant production mechanisms for these molecules in seawater. This research will provide new, quantitative insight on the impact of marine reactive gas emissions on oxidant concentrations and the production rate of secondary organic aerosol particles. The specific objectives of this research are: (1) to measure the air-sea flux of oxygenated volatile organic compounds (oVOCs), (2) to partition the observed flux between biochemical, photochemical, and heterogeneous reaction pathways using in field measurements of oVOC emission rates from collected seawater, and (3) to determine that factors that control the emission rate and production pathways for oVOC production at the air-sea interface. To carry out these objectives we will make new measurements of the air-sea flux of oVOCs and ozone via eddy covariance alongside flow reactor measurements of oVOC emission from collected seawater as a function of light intensity and oxidant exposure. The work here will make up the larger part of the Ph.D. theses for two chemistry graduate students at University of Wisconsin (UW) Madison. Elements of the field work will serve as the foundation for multiple UW Madison undergraduate independent research projects. This project will also permit the continued involvement of the Principal Investigator (PI) and Ph.D. students in education and outreach activities that bring small sensor technology to high school classrooms around the state of Wisconsin.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.