Coastal and Continental Shelf Oceanography

沿海和大陆架海洋学

• 批准号: RGPIN-2017-05157
• 负责人: Hay, Alex
• 金额: $ 1.97万
• 依托单位: Dalhousie University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=653254
• 关键词: Coastal; Continental; Shelf; Oceanography

OBJECTIVES: The long-term goal is improved predictions for the dynamic adjustment of mobile beds to combined wave-current forcing in nearshore and continental shelf environments. The primary short term goal is to pursue the use and development of advanced acoustic remote sensing systems for investigating the turbulent fluxes of momentum and sediment in the bottom boundary layer under active transport conditions, and the extreme value statistics of turbulence in high-flow tidal channels.******APPROACH: (1) A state-of-the art, high-resolution, turbulence-resolving, multi-frequency acoustic Doppler profiling system developed in-house will be used in laboratory and field experiments to remotely measure the space-time structure of velocity, turbulence and sediment flux above evolving mobile beds. (2) The variability of turbulence on 1-second to 1-month time scales will be investigated at mid-depth in high-flow tidal channels both directly, using in situ fast-response turbulence probes, and remotely, using multiple advanced acoustic Doppler systems. (3) Mobile bed adjustment to wave-current forcing in the nearshore zone and inner continental shelf during storms, and adjustment of dunes and mega-dunes to the intense turbulence and reversing current conditions in high-flow tidal channels, will be investigated using an instrumented robotic surface vehicle. ******SIGNIFICANCE: The adjustment of mobile seabed sediments to fluid forcing variability is one of the important challenges in modern ocean science. The importance resides in: (A) the applied science and societal needs for more accurate predictions of seabed change related to shoreline and coastal infrastructure protection traditionally, and now including the effects of seabed stability on the potential development of high-flow tidal channels for renewable hydroelectric power generation using in-stream turbines; (B) the effects of turbulence and seabed adjustment on the predictability of coastal and shelf-wide environmental conditions, and (C) in the potential for improved interpretation of paleo-environmental conditions through the sedimentary record. The challenges reside in: (1) the observational difficulties, (2) in the responses of the mobile sediments and the motion of the overlying fluid being both mutual and non-linear, and (3) in the fundamental connections to fluid turbulence, one of the great unsolved problems in classical physics. **

目标：长期目标是改进对近岸和大陆架环境中移动床对组合波流强迫的动态调整的预测。短期主要目标是利用和开发先进的声学遥感系统，研究主动输运条件下底部边界层动量和沉积物的湍流通量，以及高流量潮道中湍流的极值统计.*****方法：(1) 内部开发的最先进的、高分辨率、湍流解析、多频声多普勒分析系统将用于实验室和现场实验，以进行远程测量这不断变化的移动床上方的速度、湍流和沉积物通量的时空结构。 (2) 将使用原位快速响应湍流探测器直接在高流量潮汐通道的中深度研究湍流在 1 秒到 1 个月时间尺度上的变化，并使用多个先进的声学多普勒仪进行远程研究系统。 (3) 移动床对风暴期间近岸区和内大陆架波流强迫的调整，以及沙丘和巨型沙丘对高流量潮汐通道中强烈湍流和逆流条件的调整，将使用仪表化机器人地面车辆。 ******意义：移动海底沉积物对流体强迫变化的调整是现代海洋科学的重要挑战之一。其重要性在于：(A) 应用科学和社会需要更准确地预测与传统的海岸线和沿海基础设施保护相关的海底变化，现在包括海底稳定性对可再生能源高流量潮汐通道潜在开发的影响使用河内涡轮机进行水力发电； (B) 湍流和海底调整对沿海和整个大陆架环境条件可预测性的影响，以及 (C) 通过沉积记录改进对古环境条件解释的潜力。挑战在于：（1）观测困难，（2）移动沉积物的响应和上覆流体的运动是相互的和非线性的，（3）与流体湍流的基本联系，一经典物理学中尚未解决的重大问题。 **