Collaborative Research: The Dynamics of Near-Surface Velocity Structure in the Coastal Ocean from Observations and Models

合作研究：通过观测和模型研究沿海海洋近地表速度结构的动力学

• 批准号: 2219669
• 负责人: Gregory Gerbi
• 金额: $ 29.69万
• 依托单位: University of Maine
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-10-01 至 2025-09-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2219669&HistoricalAwards=false
• 关键词: Collaborative; Research; Dynamics; Near; Surface

This study will concentrate on elucidating the processes that influence the top part of the water column, from about 10 m depth to the air-water interface. This layer is unresolved by different techniques that are used to measure ocean’s near-surface currents. For example, high-frequency radars resolve the skin of the water column but provides no information underneath. On the other hand, current velocity profilers tend to miss the portion of the water column right underneath the surface. This study will attempt to fill in the gap with the help of a numerical model that resolves the hydrodynamics of the upper-ocean layer and that considers the effects of surface waves. The study will also investigate the influence on surface currents of different water densities within the surface layer. The initial proposition is that wave action will tend to homogenize the vertical distribution of near-surface currents. The project will support one graduate student and undergraduate research opportunities at University of Maine, and will develop outreach activities with US Coast Guard Academy cadets.The proposal will study the dynamics of flows in the upper meters of the coastal ocean, including the influence of surface gravity waves and the modification to the dynamics by stratification and buoyancy fluxes. This portion of the water column is rarely observed and limited to short periods, which makes it difficult to distinguish the effects of winds and waves on water velocity profiles. The approach of the study will be to pair existing HF-radar measurements with upward-looking current profilers, and compare the velocity profiles to 1D numerical model (GOTM) results with distinct turbulence parametrizations and vertical stratification. The PIs propose that wave breaking and Langmuir turbulence will tend to homogenize vertical gradients in the velocity profile, together with an Eulerian flow related to the Stokes-Coriolis mechanism. In terms of BI, beyond the scientific merit, the proposal would provide parametrizations of near-surface processes driven by waves in models and for particle trajectory studies. The study would support a graduate student and undergraduate research opportunities at University of Maine, and will develop outreach activities with USCG Academy cadets.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.

这项研究将集中于阐明影响水柱顶部（从大约 10 m 深度到空气-水界面）的过程，例如，用于测量海洋近地表流的不同技术无法解析该层。高频雷达可以解析水体的表面，但无法提供水体下方的信息。另一方面，当前的速度剖面仪往往会错过表面下方的水体部分。的帮助解析上层海洋层的流体动力学并考虑表面波影响的数值模型该研究还将研究表层内不同水密度对表面流的影响。该项目将支持缅因大学的一名研究生和本科生研究机会，并将与美国海岸警卫队学院的学员一起开展外展活动。该提案将研究高层水流的动态。海岸的海洋，包括表面重力波的影响以及分层和浮力通量对动力学的影响，这部分水柱很少被观察到并且仅限于短期，这使得很难区分风和波浪对水的影响。该研究的方法是将现有的高频雷达测量与向上的电流剖面仪配对，并将速度剖面与具有不同湍流参数化和垂直分层的一维数值模型（GOTM）结果进行比较。 PI 提出，波浪破碎和 Langmuir 湍流将趋于均匀化速度剖面中的垂直梯度，以及与 Stokes-Coriolis 机制相关的欧拉流。就 BI 而言，除了科学价值之外，该提案还将提供近场参数化。该研究将支持缅因大学研究生和本科生的研究机会，并将与美国海岸警卫队学院学员一起开展外展活动。该奖项反映了模型中由波驱动的表面过程。通过使用基金会的智力价值和更广泛的影响审查标准进行评估，NSF 的法定使命被认为值得支持。