Global Internal Tide Model from Satellite Altimetry by Resolving Multiconstituent Multimodal Multidirectional Waves

通过解析多成分、多模态、多向波，利用卫星测高建立全球内潮汐模型

• 批准号: 1947592
• 负责人: Zhongxiang Zhao
• 金额: $ 59.61万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-04-01 至 2025-03-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1947592&HistoricalAwards=false
• 关键词: Global; Internal; Tide; Model; Satellite

The global internal tide field is a superposition of waves with multiple tidal frequencies, directions, and modes. To fully understand internal tides, it is necessary to decompose their complex wave field into a series of simpler monochromatic plane waves. The principal investigator has developed a wave decomposition technique suitable for use with data from both satellite sea surface elevation (altimetry) data and numerical simulations that enables the discovery of unprecedented features hidden in the raw internal wave field. This project will further develop the technique and apply it to satellite altimetry covering the global ocean. The results will be used to construct global maps of internal wave tidal components, provide estimates of their seasonal and interannual variability and their contribution to ocean mixing. The accuracy of the satellite observed decomposed internal tides will be evaluated using existing data from field measurements and numerical simulations. The product of this research will be useful for the design of field experiments and modeling of internal tides. In addition, it will benefit research on other ocean processes influenced by internal tides (e.g., primary productivity, ocean acoustics, coral reef bleaching, ocean mixing etc.). A series of animations of internal tide products will be created and shared to the public via YouTube. Some of the animations will also be used to teach children about the ocean and satellite technology. This project will support a full-time graduate student at the University of Washington.Internal tides are ubiquitous in the world oceans but still poorly understood due to the scarcity of field observations with sufficient spatial and temporal resolution. Satellite altimetry is the only practical technique for observing internal tides on the global scale. A previously developed technique applicable to both satellite altimeter data and numerical simulations and capable of decomposing a given internal tide field into multimodal multidirectional waves will be further expanded and applied on a global scale with the aim to: (1) construct global maps of mode-1–3 M2, S2, O1 and K1 internal tides from satellite altimetry; (2) quantify their seasonal and interannual variations; and (3) calculate along-beam decay rates and internal tide driven ocean mixing. The new global internal tide model will consist of separately resolved waves of different frequencies, different baroclinic modes and different horizontal propagation directions. The satellite observed internal tides will be validated against in-situ observations and MITgcm global circulation model simulations.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.

全球内潮汐场是多种潮汐频率、方向和模式的波浪的叠加，为了充分了解内潮汐，有必要将其复杂的波场分解为一系列更简单的单色平面波。波分解技术适用于卫星海面高程（测高）数据和数值模拟，能够发现隐藏在原始内部波场中的前所未有的特征。该项目将进一步开发该技术并将其应用于卫星测高覆盖。全球的结果将用于构建内波潮汐成分的全球地图，提供其季节和年际变化及其对海洋混合的贡献的估计。将使用现场测量的现有数据来评估卫星观测到的分解内潮汐的准确性。这项研究的成果将有助于现场实验的设计和内潮汐建模，此外，还将有利于受内潮汐影响的其他海洋过程（例如初级生产力、海洋声学、珊瑚礁）的研究。漂白, 海洋一系列的内潮汐产品动画将被制作并通过YouTube向公众分享，其中一些动画还将用于向孩子们教授海洋和卫星技术。华盛顿大学的研究生。内潮汐在世界海洋中普遍存在，但由于缺乏足够空间和时间分辨率的现场观测，人们对内潮汐的了解仍然很少。卫星测高是在全球范围内观测内潮汐的唯一实用技术。之前开发的一款适用于卫星高度计数据和数值模拟并能够将给定内潮场分解为多模态多向波的技术将在全球范围内进一步扩展和应用，目的是：（1）构建模式1-3的全球地图来自卫星测高的 M2、S2、O1 和 K1 内潮汐；(2) 量化它们的季节和年际变化；以及 (3) 计算沿波束衰减率和内潮驱动的海洋混合。卫星观测到的内潮汐将通过现场观测和MITgcm全球环流模型模拟进行验证。该奖项反映了NSF的法定使命，并通过评估认为值得支持。利用基金会的智力优势和更广泛的影响审查标准。