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.

该项目与量化和绘制昼夜和半衰减的斜压潮有关，即海洋中的内波，这是由于太阳和月亮强迫的偏压潮汐损失的结果。这项工作将主要使用由全球漂流者计划（GDP）的表面漂移浮标（GDP）轨迹提供的海洋近表面小时电流的独特数据集。该方法的指导是对潮汐能学的分析，该潮汐能分析时间均值或相锁的斜压潮和时间变化或非相锁的斜压潮汐潮汐。 GDP数据集既足够大又足够准确，因此应允许对两种斜压潮汐进行定量评估，并专门测试了将相锁定潮汐散射到非相锁定潮汐中的理论模型。此外，分析将允许对耗散速率系数及其相关的动力学过程的相锁和非相锁定潮汐进行映射 - 根据地理位置和环境条件，它们可以与众不同。这种映射将提供急需的信息，以改善海洋通用循环模型中潮汐混合的现实性和物理参数化。这项工作将有助于测量全球尺度上海流的目标，该电流普遍存在在潮汐频率下表现出充满活力的振荡。对海面流的改进预测将对从运输行业到季节性气候预报员的利益相关者产生社会影响。该项目还将为气候主题的教育计划做出贡献，包括夏令营，动手活动以及对现有的学校实地考察计划的增强。目前可以从卫星高度计数据的分析中获得相锁的潮汐，并且这些估计结果导致了Barocloclinic潮汐模型的创建，该项目将使用GDP数据进行测试和扩展数据。由于潮汐动力学既包括波浪散射又包括波浪耗散，因此测试这些模型将在区域和全局尺度上对这些过程的物理合理参数化范围内构成约束。最后，GDP数据应与潮汐和中尺度分辨的海洋全球循环模型的输出进行系统的比较，该练习将有助于验证模型模拟，并为了解GDP观察值和应用统计方法的潜在偏见提供了有用的背景。该项目将产生有关潮汐电流的新知识，以便更好地了解潮汐动态及其在维持全球热盐循环中的作用。新的Drifter数据集将用于研究斜力潮汐现象，既足够大且独特（在时间，空间和准确性上），以提供对潮汐性质的定量描述。此外，还将获得对潮汐/非潮汐相互作用的定性和潜在的新评估，包括它们的季节性和更长的时间变化。提议将潮汐能预算的新型分解分开，该过程主要影响相锁定和非相锁定的潮汐信号，以指导对Drifter观察的分析和解释，以及高度学数据和数字模拟的分析和解释。这一奖项反映了NSF的法定任务和综述，这是通过评估的范围来进行的。

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.