Collaborative Research: Impacts of surface ocean surfactant sources and transformations on their chemical composition and air-sea relevant properties

合作研究：海洋表层表面活性剂来源及其转化对其化学成分和海气相关特性的影响

基本信息

批准号：
2123368
负责人：
Amanda Frossard
金额：
$ 34.09万
依托单位：
University of Georgia Research Foundation Inc
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2021
资助国家：
美国
起止时间：
2021-10-01 至 2024-09-30
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=2123368&HistoricalAwards=false
关键词：
Collaborative Research Impacts surface ocean

项目摘要

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2).The surface microlayer (SML), the thin layer of water at the interface between the ocean and the atmosphere, controls the exchange of materials to and from the ocean. As a result, it can profoundly influence biogeochemical cycles and global climate. One type of chemical species that accumulates at this interface are surfactant molecules, which influence the surface tension of and the rate of material exchange at air-water interfaces. Biological and chemical production and degradation processes represent surfactant sources and removal pathways, but the relative importance of those processes for determining surfactant quantities and molecular composition remains unclear. Similarly, the relationship between surfactant molecule composition and surface tension at the air-water interface has not been established. As a result, their effects on material exchange at the interface cannot currently be predicted. This work will use measurements at sea, laboratory experiments, and high-resolution analyses to measure the chemical and physical characteristics of surfactants and their properties at the air-sea interface. An improved understanding of surfactant processes and surface ocean will benefit society by improving our understanding of the exchange of climate-relevant gases and particles. Two early career PIs will advance their established collaboration and gain further experience leading research projects and mentoring students. Students will receive valuable hands-on training in oceanographic field collections, state-of-the-science analytical techniques, data interpretation, and data dissemination. The results and methodologies from this work will be featured in courses at the University of Georgia and the University of Delaware and will be developed into content for K-12 students, enhancing infrastructure for education. This work includes the unique pairing of state-of-the-science measurements across time and spatial scales to assess the influence of oceanographic processes on surfactant chemical composition and physical air-sea relevant properties. SML and subsurface waters will be collected from estuarine, coastal ocean, and open ocean sites during high and low productivity conditions to establish surfactant molecular characteristics over a range of space, time, and ocean biological activity. The effects of light will be assessed via diurnal sampling efforts and laboratory experiments. Samples will be analyzed for their detailed chemical, biological, and physical characteristics. The surface tension of the SML is expected to be inversely correlated with the abundance of lipid-like compounds (low O content, high H/C ratios, e.g., sulfur-containing lipids) produced during periods of high biological activity. Prolonged exposure to light is hypothesized to result in photo-oxidation of surfactant compounds, higher abundances of oxygenated and lower molecular weight aliphatic compounds, and increased surface tension. Multivariate statistical approaches will be used to reveal a mechanistic understanding of the links between biological and photochemical processes and the resulting surfactant and SML chemical and physical characteristics. This new knowledge will represent a first step toward improved models of the air-sea exchange of climate relevant gases which currently have large uncertainties. It will inform future work on the exchange of volatile and aerosol organics with significant potential impacts for our understanding of the climate system.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.

该奖项是根据2021年《美国救援计划法》（公共法第117-2）的全部或部分资助的。地表微层（SML），海洋与大气之间的界面上的水层薄层控制着从海洋和海洋的材料交换。结果，它可以深刻影响生物地球化学周期和全球气候。在该界面积聚的一种化学物种是表面活性剂分子，它会影响空气水接口处的材料交换的表面张力和速率。生物学和化学生产和降解过程代表表面活性剂的来源和去除途径，但是这些过程对于确定表面活性剂量和分子组成的相对重要性尚不清楚。同样，尚未建立表面活性剂分子组成与表面张力之间的关系。结果，目前无法预测它们对接口上材料交换的影响。这项工作将使用海上测量，实验室实验和高分辨率分析，以测量表面活性剂的化学和物理特征及其在空气接口处的特性。对表面活性剂过程和表面海洋的改进理解将通过提高我们对与气候相关气体和颗粒的交换的了解，从而使社会受益。两个早期的职业生涯将推进他们既定的合作，并获得进一步的经验领先的研究项目和指导学生。学生将在海洋现场收集，最先进的分析技术，数据解释和数据传播方面接受宝贵的动手培训。这项工作的结果和方法将在佐治亚大学和特拉华大学的课程中介绍，并将发展为K-12学生的内容，从而增强教育基础设施。这项工作包括跨时间和空间量表的最先进测量的独特配对，以评估海洋过程对表面活性剂化学成分和物理空气相关特性的影响。在高生产率和低生产力条件下，将从河口，沿海海洋和开放海洋地点收集SML和地下水域，以在一系列时空，时间和海洋生物学活动中建立表面活性剂分子特征。光的影响将通过昼夜抽样工作和实验室实验进行评估。将分析样品的详细化学，生物学和物理特征。预计SML的表面张力与在高生物活性时期产生的脂肪样化合物（低O含量，高H/C比，例如含硫脂质）的丰度成反比。假设长时间暴露于光线会导致表面活性剂化合物的光氧化，氧化和较低分子量脂肪族化合物的较高丰度以及表面张力的增加。多元统计方法将用于揭示对生物学和光化学过程以及所得的表面活性剂和SML化学和物理特征之间联系的机械理解。这些新知识将是改善气候相关气体交换模型的第一步，这些气体目前具有大量不确定性。它将为未来的挥发性和气溶胶有机物交换的工作提供依据，并对我们对气候系统的理解产生重大影响。该奖项反映了NSF的法定任务，并且使用基金会的知识分子和更广泛的影响评估审查标准，认为值得通过评估来支持。