CAREER: Benthic Boundary Mixing and Dissolved Oxygen Transfer at the Sediment Water Interface in a Stratified Lake

摘要建议编号：CTS-9703451首席研究员：本佐这是一项研究热成层湖泊中底栖边界混合的职业资助。现场测量将在五个淡水湖进行。海底边界层的湍流特性将使用自备的微型剖面仪和声学多谱勒测速仪进行研究。用热电阻链测量湖盆内的内波特性。将讨论几个问题，例如：(1)在倾斜边界层内产生湍流的主要机制(2)海底边界层内上坡体积通量的大小和相关的循环时间尺度。(3)确定湍流边界层厚度是由湍流娱乐还是由倾斜边界附近的内波特性决定。(4)底栖边界层内的垂直涡旋扩散率能否与整个湖泊的动力稳定性(湖数)相关？实验室实验将重点放在沉积物-水界面的界面气体传输机理的细节上。还将在实验室通道中测量各种海底沉积物在大范围雷诺数范围内的近床液体湍流和溶解氧(DO)浓度。DO微剖面的测定与近床湍流的表征相结合，将解决与DO分布有关的一系列问题。研究结果将为验证现有概念模型提供机会，并促进新模型的开发，这些模型可以提高我们预测湖泊、水库和沿海水域的水质和运输相关参数的能力。

ABSTRACT Proposal Number: CTS-9703451 Principal Investigator: Hondzo This is a CAREER grant to study benthic boundary mixing within thermally stratified lakes. Field measurements will be conducted in five freshwater lakes. Turbulent properties of the benthic boundary layer will be investigated using a self-contained microprofiler augmented with the acoustic Doppler velocimeter. The internal wave characteristics within the lake basin will be measured with thermistor chains. Several issues will be addressed such as: (1) The primary mechanism for generating turbulence within the sloping boundary layer (2) The magnitude of the up slope volume flux and associated cycling time scales within the benthic boundary layer. (3) Determination of whether the turbulent boundary layer thickness is determined by the turbulent entertainment or by the internal wave characteristics near the sloping boundaries. and (4) Whether the vertical eddy diffusivity within the benthic boundary layer can be correlated with the dynamic stability (Lake Number) of the entire lake? Laboratory experiments will focus on the details of the interfacial gas transfer mechanism at the sediment-water interface. Near-bed liquid turbulence and dissolved oxygen (DO) concentrations will be also be measured in a laboratory channel over a wide range of Reynolds number, for a variety of bottom sediments. The determination of DO microprofiles in conjunction with characterization of near-bed turbulence will address a wide range of questions concerning the distribution of DO. The research results will provide an opportunity to validate the existing conceptual models, as well as enhance the development of new models which can improve our ability to predict water quality and transport related parameters in lakes, reservoirs, and coastal waters.