Regional Studies of Internal Tides from Altimetry

利用测高法进行内潮汐区域研究

• 批准号: 0623540
• 负责人: Gary Egbert
• 金额: $ 37.86万
• 依托单位: Oregon State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-09-15 至 2012-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0623540&HistoricalAwards=false
• 关键词: Regional; Studies; Internal; Tides; Altimetry

OCE-0623540Intellectual MeritInternal waves generated by the surface tide are a potential source of energy for vertically mixing the deep ocean. To date, analysis of altimetry data has provided gross global scale maps of energy lost from the surface tide, as well as a qualitative picture of low-mode internal tides propagating in the open ocean. However, many important questions remain, especially with regard to the processes, rate and spatial distribution of energy loses from the internal tide. An analysis of the internal tide at a suite of regions in the world ocean will be conducted using the generalized inversion of a primitive-equation model to assimilate satellite altimetry data. The main goal is to study the generation, propagation, and dissipation of the internal tide at sites which differ in topography (island arcs, mid-ocean ridges, and abyssal plains), position relative to the critical latitude, and proximity to the continental shelf, and assess the impact of mesoscale and seasonal variability on harmonic constants inferred from altimetry. Intercomparison of a range of different sites, including mapping of low-mode internal tide energy fluxes, and analysis of residuals in the data assimilation solutions, will permit the generalization of inferences based on relatively sparse in situ measurements of the tides and mixing, and help to elucidate mechanisms for the dissipation of the internal tides.Broader ImpactsTidally driven mixing is poorly if at all represented in the current generation of ocean climate models, and this study will be directly relevant to researchers who are developing energetically consistent parameterizations for ocean mixing. The detailed maps of the internal tide will also provide a second-order tidal correction for altimetry obtained by the multiple missions now in orbit which are currently used to study mesoscale and longer-term processes. In addition, the computational tools refined and developed in this study will be useful in the creation of regional ocean prediction systems that utilize data-assimilative methodologies.

OCE-0623540智力优点由表面潮汐产生的内波是深海垂直混合的潜在能源。到目前为止，测高数据的分析提供了总的全球范围内的能量损失的地图，从表面潮汐，以及低模式的内部潮汐在公海传播的定性图片。然而，许多重要的问题仍然存在，特别是关于从内潮的能量损失的过程，速率和空间分布。将利用一个连续方程模型的广义反演来同化卫星测高数据，对世界海洋一系列区域的内潮进行分析。主要目标是研究在地形（岛弧、洋中脊和深海平原）、相对于临界纬度的位置和与大陆架的接近程度不同的地点内潮的产生、传播和消散，并评估中尺度和季节变化对从测高学推断的调和常数的影响。对一系列不同地点进行相互比较，包括绘制低模态内潮能通量图和分析数据同化解决方案中的残差，将允许根据相对稀疏的潮汐和混合原位测量结果进行推断，更广泛的影响潮汐驱动的混合在目前这一代的海洋气候模型，这项研究将直接关系到研究人员谁正在制定积极一致的参数化海洋混合。详细的内潮图还将对目前用于研究中尺度和长期过程的在轨多个飞行任务所获得的测高数据进行二阶潮汐校正。此外，在这项研究中改进和开发的计算工具将有助于建立利用数据同化方法的区域海洋预测系统。