Collaborative Research: Mapping the kinematics and dynamics of tidal ocean currents with surface drifters

合作研究：利用表面漂流物绘制潮汐洋流的运动学和动力学图

• 批准号: 2102740
• 负责人: Edward Zaron
• 金额: $ 15.56万
• 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: 2020
• 资助国家: 美国
• 起止时间: 2020-05-01 至 2025-04-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2102740&HistoricalAwards=false
• 关键词: Collaborative; Research; Mapping; kinematics; dynamics

This project is concerned with quantifying and mapping diurnal and semi-diurnal baroclinic tides, that is, internal waves in the ocean that are the result of the loss of energy from the barotropic tides forced by the Sun and the Moon. This work will primarily use a unique dataset of oceanic near-surface hourly currents provided by the trajectories of surface drifting buoys from the Global Drifter Program (GDP). The approach is guided by an analysis of tidal energetics which distinguishes between time-mean, or phase-locked, baroclinic tides and time-variable, or non-phase-locked, baroclinic tides. The GDP dataset is both large enough and sufficiently accurate that it should permit quantitative assessment of both types of baroclinic tides, and specifically test theoretical models for the scattering of phase-locked tides into non-phase-locked tides. In addition, the analyses will permit the mapping---for both phase-locked and non-phase-locked tides---of dissipation rate coefficients and their associated dynamical processes, which can be distinct based on geographical locations and environmental conditions. Such mapping will provide much needed information for improving the realism and physical parameterization of tidal mixing in ocean general circulation models. The work will contribute to the goal of measuring on a global scale upper-ocean currents which ubiquitously exhibit energetic oscillations at tidal frequencies. Improved prediction of ocean surface currents will have societal impacts for stakeholders ranging from the shipping industry to seasonal climate forecasters. The project will also contribute to a climate-themed educational program including summer camps, hands-n activites, and enhancements to existing school field trip programs.Estimates of the phase-locked tides are presently available from the analysis of satellite altimeter data,and these estimates have led to the creation of baroclinic tide models, which this project will test and extend using the GDP data. As tidal dynamics includes both wave scattering and wave dissipation, testing these models will place constraints on the range of physically plausible parameterizations for these processes on regional and global scales. Finally, the GDP data shall be systematically compared with outputs of a tide and mesoscale-resolving ocean global circulation model, an exercise which will be useful for validating the model simulations as well as providing a useful context for understanding potential biases of the GDP observations and statistical methods applied. This project will generate new knowledge concerning tidal currents in order to better understand tidal dynamics and their role in the maintenance of the global thermohaline ocean circulation. The new drifter dataset that will be utilized to investigate baroclinic tidal phenomena is both large enough and unique (temporally, spatially and accuracy wise) to provide a quantitative description of tidal properties. In addition, qualitative and potentially new assessments of tidal/non-tidal interactions will be obtained, including their seasonal and longer temporal variability. A novel decomposition of the tidal energy budget, which separates processes primarily affecting phase-locked and non-phase-locked tidal signals, is proposed to guide the analysis and interpretation of the drifter observations, as well as altimetry data and numerical 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.

该项目关注的是对日斜压潮汐和半日斜压潮汐进行量化和测绘，即海洋中的内波，这是太阳和月球迫使正压潮汐损失能量的结果。这项工作将主要使用一个独特的海洋近地表每小时洋流数据集，该数据集由全球漂流计划（GDP）提供的地表漂流浮标轨迹提供。该方法以潮汐能量学分析为指导，该分析区分了时间平均的或锁相的斜压潮汐和时变的或非锁相的斜压潮汐。GDP数据集既足够大又足够准确，它应该允许对两种斜压潮汐进行定量评估，并专门测试锁相潮汐向非锁相潮汐散射的理论模型。此外，这些分析将允许对锁相和非锁相潮汐的耗散率系数及其相关的动力过程进行映射，这些过程可以根据地理位置和环境条件而不同。这种制图将为改善海洋环流模式中潮汐混合的真实感和物理参数化提供急需的信息。这项工作将有助于在全球范围内测量在潮汐频率上普遍表现出能量振荡的上层洋流。改善对海洋表面洋流的预测将对从航运业到季节性气候预报员等利益相关者产生社会影响。该项目还将为气候主题的教育项目做出贡献，包括夏令营、动手活动和改进现有的学校实地考察项目。目前可以通过对卫星高度计数据的分析来估计锁相潮汐，这些估计导致了斜压潮汐模型的建立，该项目将使用GDP数据对其进行测试和扩展。由于潮汐动力学包括波散射和波耗散，测试这些模式将限制这些过程在区域和全球尺度上物理上合理的参数化范围。最后，将GDP数据与潮汐和中尺度海洋全球环流模式的输出进行系统比较，这将有助于验证模式模拟结果，并为理解GDP观测结果和所采用的统计方法的潜在偏差提供有用的背景。这个项目将产生关于潮流的新知识，以便更好地了解潮汐动力学及其在维持全球温盐海洋环流中的作用。将用于调查斜压潮汐现象的新漂移数据集既大又独特（时间，空间和精度方面），可以提供潮汐特性的定量描述。此外，将获得潮汐/非潮汐相互作用的定性和可能新的评价，包括它们的季节性和较长时间变率。提出了一种新的潮汐能收支分解方法，将主要影响锁相和非锁相潮汐信号的过程分离开来，用于指导漂船观测数据、高程数据和数值模拟的分析和解释。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

An Assessment of Global Ocean Barotropic Tide Models Using Geodetic Mission Altimetry and Surface Drifters

• DOI: 10.1175/jpo-d-20-0089.1
• 发表时间: 2020-11
• 期刊: Journal of Physical Oceanography
• 影响因子: 3.5
• 作者: E. Zaron;S. Elipot

Near‐Surface Oceanic Kinetic Energy Distributions From Drifter Observations and Numerical Models

来自漂流者观测和数值模型的近地表海洋动能分布

• DOI: 10.1029/2022jc018551
• 发表时间: 2022
• 期刊: Journal of Geophysical Research: Oceans
• 作者: Arbic, Brian K.;Elipot, Shane;Brasch, Jonathan M.;Menemenlis, Dimitris;Ponte, Aurélien L.;Shriver, Jay F.;Yu, Xiaolong;Zaron, Edward D.;Alford, Matthew H.;Buijsman, Maarten C.
• 通讯作者: Buijsman, Maarten C.