Colaborative Research: Influence of wind and bottom generated turbulence on air-sea gas exchange in shallow water environments

合作研究：风和底部产生的湍流对浅水环境中海气交换的影响

• 批准号: 1829657
• 负责人: Fabrice Veron
• 金额: $ 34.72万
• 依托单位: University of Delaware
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-10-01 至 2024-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1829657&HistoricalAwards=false
• 关键词: Colaborative; Research; Influence; wind; bottom

Air-sea transfers of energy and gases are critically important for predictions of short term weather, as well as long term climate trends. Over the past decades, considerable effort has been devoted to parameterizing these fluxes in terms of widely measured variables such as wind speed. However, these parameterizations are inadequate in shallow coastal regions where fetch, waves, and bottom-generated turbulence influence the physical mechanisms responsible for the air-sea fluxes, which have implications for our ability to understand important environmental processes such as coral reef metabolism or carbon cycling. Furthermore, shallow coastal water ecosystems are susceptible to anthropogenic pollution, leading to hypoxia or anoxia. In order to understand the future states of these ecosystems that are exposed to continued anthropogenic perturbations, biogeochemical budgets and fluxes have to be established, including exchanges across the air-water interface, i.e., they require quantitative knowledge of factors controlling gas exchange. This project will measure the air-sea gas fluxes and multiple physical variables contributing to their variability in a shallow coral reef. It is anticipated that the results from this study will yield improved understanding of the influence of physical processes such as wind, currents, waves on producing surface-, and bottom-driven turbulence, and how they control air-sea gas exchange in shallow coastal waters. They should also allow these processes to be parameterized in terms of easily measured environmental variables such as wind speeds, current velocities, and water depth. On a more local level, the PIs will continue their efforts toward disseminating scientific understanding in the field of physical and chemical oceanography by participating in undergraduate research opportunities, local science events targeted at K-12 students, and graduate student advising. This project will provide multidisciplinary training to two graduate students, and an undergraduate student.A series of experiments will be performed over two consecutive years on the barrier reef of Kane'ohe Bay, Hawaii to determine factors that control gas exchange in shallow ocean environments. During the experiment, gas transfer velocities will be measured with tracers (N2O, SF6, Rhodamine WT) and eddy covariance of CO2, along with concurrent measurements of processes such as wind, current, waves and turbulence. With the data collected in Kane'ohe Bay, the PIs will: (i) Assess when or whether it is valid to apply open ocean wind speed/gas exchange parameterizations toshallow water environments (ii) Improve our understanding of how physical processes such as wind, currents, waves interact with the shallow bottom to produce surface-, and bottom-driven turbulence (iii) Examine how surface and bottom generated turbulence control air-sea gas exchange in shallow coastal waters (iv) Parameterize gas exchange in shallow water environments in terms of easily measured environmental variables such as wind speeds, current velocities, and water depth.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.

能源和气体的海空转移对于预测短期天气以及长期气候趋势至关重要。在过去的几十年里，人们投入了大量的精力来根据风速等广泛测量的变量来参数化这些通量。然而，这些参数化在浅海沿海地区是不够的，在这些地区，取水、波浪和底部产生的湍流会影响造成海气通量的物理机制，这对我们理解珊瑚礁代谢或碳循环等重要环境过程的能力有影响。此外，沿海浅水生态系统容易受到人为污染，导致缺氧或缺氧。为了了解这些遭受持续人为扰动的生态系统的未来状态，必须建立生物地球化学预算和通量，包括空气-水界面上的交换，即，它们需要控制气体交换的因素的定量知识。该项目将测量浅海珊瑚礁中空气-海洋气体通量和导致其变化的多个物理变量。预计这项研究的结果将有助于更好地了解风、洋流、波浪等物理过程对产生表面和底部驱动的湍流的影响，以及它们如何控制沿海浅水区的空气-海洋气体交换。它们还应该允许这些过程根据易于测量的环境变量（例如风速、水流速度和水深）进行参数化。在地方层面上，PI 将继续努力通过参与本科生研究机会、针对 K-12 学生的当地科学活动以及研究生咨询，传播物理和化学海洋学领域的科学理解。该项目将为两名研究生和一名本科生提供多学科培训。将在夏威夷卡内奥赫湾的堡礁上连续两年进行一系列实验，以确定浅海环境中控制气体交换的因素。实验期间，将使用示踪剂（N2O、SF6、罗丹明 WT）和 CO2 涡流协方差来测量气体传输速度，同时测量风、水流、波浪和湍流等过程。利用卡内奥赫湾收集的数据，PI 将： (i) 评估何时或是否有效将开放海洋风速/气体交换参数化应用于浅水环境 (ii) 提高我们对风、海流、波浪等物理过程如何与浅水底部相互作用以产生表面和底部驱动的湍流的理解 (iii) 研究表面和底部产生的湍流如何控制沿海浅水区的空气-海水交换 (iv) 根据易于测量的环境变量（例如风速、海流速度和水深）对浅水环境中的气体交换进行参数化。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力优点和更广泛的影响审查标准进行评估，被认为值得支持。