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

能量和气体的海气传输对于短期天气和长期气候趋势的预测至关重要。在过去的几十年里，已经投入了相当大的努力，参数化这些通量的广泛测量的变量，如风速。然而，这些参数化是不够的，在浅水沿海地区的取风，波浪和底部产生的湍流影响的物理机制负责的海气通量，这对我们的能力，以了解重要的环境过程，如珊瑚礁代谢或碳循环的影响。此外，沿海浅水生态系统易受人为污染，导致缺氧或缺氧。为了了解这些生态系统在持续人为扰动下的未来状态，必须确定生物地球化学收支和通量，包括空气-水界面的交换，即，它们需要控制气体交换的因素的定量知识。该项目将测量海气通量和导致其在浅珊瑚礁中变化的多种物理变量。预计这项研究的结果将产生更好的了解物理过程，如风，电流，波浪对生产表面和底部驱动的湍流的影响，以及它们如何控制在沿海浅沃茨的海气交换。它们还应使这些过程能够根据容易测量的环境变量（如风速、流速和水深）进行参数化。在更多的地方层面上，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和研究生咨询来传播物理和化学海洋学领域的科学认识。该项目将为两名研究生和一名本科生提供多学科培训。将连续两年在夏威夷凯恩奥赫湾堡礁进行一系列实验，以确定控制浅海环境中气体交换的因素。在实验过程中，将用示踪剂（N2 O、SF6、罗丹明WT）和CO2涡动协方差测量气体传输速度，沿着风、流、波和湍流等过程的同时测量。根据在凯恩奥赫湾收集的数据，PI将：（一）评估何时或是否有必要对浅水环境采用开阔洋风速/气体交换参数化方法;（二）增进我们对风、海流、波浪等物理过程如何与浅水底部相互作用以产生表层-（iii）研究表面和底部产生的湍流如何控制沿海浅沃茨中的气-海气体交换（iv）根据容易测量的环境变量，如风速，流速，该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

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.