NSFGEO-NERC: Collaborative Research: Properties and Mechanisms of the Multiscale Eddy-Induced Diffusion

海洋漩涡是热量、营养物质、碳和污染物等特性分布的基础。这个项目将研究海洋涡旋在时间和空间上的分布特性的影响。该项目使用地球物理流体动力学的既定理论、一套最先进的数值模型和海洋观测来研究涡流如何在空间和时间上分布特性。结果将是一组数据，可以用来改进海洋环流和气候数值模型中旋涡影响的表示。该项目是美国和英国(UK)之间的合作，英国部分由英国国家环境研究委员会(NERC)通过与NSF达成的一项协议提供支持。该项目将探索中纬度不均匀和各向异性涡流诱导的输送特性，并研究它们对示踪剂分布的重要性。涡旋引起的输运将通过涡旋扩散率张量的时空映射来量化，这将被分析以探索结果对用于定义涡旋的空间和时间尺度的依赖性。然后，这张扩散系数图将被用来在不能完全解决涡动驱动的示踪剂平流的流动中产生示踪剂分布，由此产生的技能将被量化。将使用一系列涡旋解析数值模拟和漂流浮标观测。这项研究将促进对不同过程和尺度如何、在哪里以及为什么对物质运输做出贡献的基本理解，并将开发新的方法来估计尺度感知的涡流扩散张量。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Ocean eddies are fundamental to the distribution of properties such as heat, nutrients, carbon, and pollutants. This project will examine the effects of ocean eddies in distributing properties over time and space. The project uses established theory in geophysical fluid dynamics, a suite of state of the art numerical models, and ocean observations to examine how eddies distribute properties over space and time. The results will be a set of data that can be used to improve representations of the effects of eddies in numerical models of the ocean circulation and climate. The project is a collaboration between the US and the United Kingdom (UK) with the UK component being supported by the UK National Environmental Research Council (NERC) through an agreement with NSF.This project will explore properties of the inhomogeneous and anisotropic eddy-induced transport at mid-latitudes and examine their importance for tracer distribution. The eddy-induced transport will be quantified by a spatio-temporal map of the eddy diffusivity tensor which will be analyzed to explore the dependence of the results on the spatial and temporal scales used to define the eddies. This diffusivity map will then be used to produce tracer distributions in flows that do not fully resolve the eddy-driven tracer advection, and the resulting skill will be quantified. A hierarchy of eddy-resolving numerical simulations and observations from drifting buoys will be used. The study will advance fundamental understanding of how, where, and why different processes and scales contribute to the material transport and will develop novel methods for estimating scale-aware eddy diffusivity tensors.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.