Energy Pathways and Scale Interactions in the Ocean

海洋中的能量路径和尺度相互作用

• 批准号: 1259794
• 负责人: Geoffrey Vallis
• 金额: $ 36.51万
• 依托单位: Princeton University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-03-15 至 2017-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1259794&HistoricalAwards=false
• 关键词: Energy; Pathways; Scale; Interactions; Ocean

Large-scale currents and eddies pervade the ocean and play a prime role in the general circulation and climate. The coupling between scales ranging from ten thousand kilometers to a millimeter presents a major difficulty in understanding, modeling, and predicting oceanic circulation and mixing. What are the power requirements to sustain turbulence and mixing in the ocean? What are its sources and sinks? What are the mechanisms to transfer such energy across scales? Due to the lack of rigorous quantitative methods for detecting and measuring energy transfer rates between scales in the ocean, our understanding of the oceanic energy budget is uncertain within at least a factor of two and possibly as large as ten. This poses serious limitations on our climate prediction capabilities. Using a novel mathematical scale-analysis framework, we propose to study the coupling between scales and map out the energy pathways from realistic ocean model data. The approach is very general, allows for probing the dynamics simultaneously in scale and in space, and is not restricted by the usual assumptions of homogeneity or isotropy, thus making it ideally suited for studying oceanic flows. A primary goal is to examine the extent to which the accepted geostrophic model for such pathways is valid in the ocean.The contribution of various nonlinear mechanisms to the transfer of energy across scales such as baroclinic and barotropic instabilities, barotropization, Rossby wave generation, and internal wave generation and breaking will be investigated. If successful, this research will provide oceanographers with a promising set of tools with which to analyze and interpret data from simulations, satellite measurements, and experiments.Intellectual Merit: Understanding and quantifying the oceanic energy pathways and balances as a function of scale is a challenging fundamental problem in oceanography. To this end, rigorous analytical tools will be further developed and to applied to data from global, regional, and idealized numerical simulations. The problem of understanding nonlinear interactions in the ocean is a major intellectual challenge and new techniques and ideas will be applied to better quantify the energetics of the ocean.Broader Impacts:Mapping and quantifying the energy pathways supplying and depleting the mesoscale flow will reduce the current uncertainty in the oceanic energy budget. The work also promises to provide insights into the scale-physics at play in the ocean, offer a priori constraints on parameter tuning of current parameterization schemes such as Gent-McWilliams, on proposed schemes that may be applied to eddy permitting ocean models, and will help in the development of a new class of ocean parameterizations that are a function of location and resolution.The work will support a junior scientist at the threshold of a promising career. Finally, the P.I. will be revising a general textbook that has been adopted by a number of universities for the teaching of atmospheric and oceanic dynamics. The book will help education in the geosciences broadly, and the research conducted under this project will provide context and examples for the students.

大规模的洋流和漩涡遍布海洋，在大气环流和气候中发挥着重要作用。从一万公里到一毫米的尺度之间的耦合是理解、建模和预测海洋环流和混合的主要困难。维持海洋中的湍流和混合需要什么功率？它的源和汇是什么？在不同尺度上传递这种能量的机制是什么？由于缺乏严格的定量方法来检测和测量海洋中尺度之间的能量转移率，我们对海洋能量收支的理解至少在两个因素之内是不确定的，可能高达十个。这严重限制了我们的气候预测能力。使用一种新的数学尺度分析框架，我们建议研究尺度之间的耦合，并从现实的海洋模型数据绘制出的能量路径。该方法非常通用，可以同时在规模和空间上探测动力学，并且不受通常的同质性或各向同性假设的限制，因此非常适合研究洋流。一个主要的目标是检查在何种程度上被接受的地转模式的这种途径是有效的海洋。各种非线性机制的贡献，如斜压和正压不稳定性，正压，Rossby波的产生，和内波的产生和破碎跨尺度的能量传输将被调查。如果成功的话，这项研究将为海洋学家提供一套很有前途的工具，用于分析和解释模拟，卫星测量和实验数据。智力优点：理解和量化海洋能量途径和平衡作为尺度的函数是海洋学中一个具有挑战性的基本问题。为此，将进一步开发严格的分析工具，并将其应用于全球、区域和理想化数值模拟的数据。理解海洋中非线性相互作用的问题是一个重大的智力挑战，新的技术和思想将被应用于更好地量化海洋的能量学。更广泛的影响：绘制和量化中尺度流的能量供应和消耗路径将减少目前海洋能量收支的不确定性。这项工作还有望提供对海洋中起作用的尺度物理学的见解，对Gent-McWilliams等当前参数化方案的参数调整提供先验约束，对可能适用于涡流允许海洋模型的拟议方案提供先验约束，并将有助于开发一种新的海洋参数化，这种参数化是位置和分辨率的函数。这项工作将支持一位年轻的科学家，有前途的职业生涯的门槛。最后私家侦探将修订一些大学采用的大气和海洋动力学教学通用教科书。这本书将广泛地帮助地球科学教育，在这个项目下进行的研究将为学生提供背景和例子。