Collaborative research: Deep eastern ocean boundary currents from local submesoscale potential vorticity dynamics to global climate implications

在所有南半球洋盆的观测研究中反复出现大量东部深部边界流的证据。这些极地气流的核心承载着经向翻转环流的一个重要组成部分。这些深向极地流动发生在某些地区，其特征是赤道表面流和向极地潜流。这些气流影响南大洋水团结构，是深层大气环流的重要组成部分。然而，它们的动态还没有被很好地理解，它们要么没有得到很好的描述，要么在气候模型中根本没有表现出来。这项研究将是第一次试图了解深部东部边界流的动态及其对气候模拟和预测的影响。该项目包括培训两名研究生，一名博士后研究人员，以及通过万维网向公众宣传。该项目使用各种观测分析、贝叶斯逆模式和高分辨率区域海洋模式来研究深海东部边界流。高分辨率海洋模式可以解决中、亚中尺度涡旋过程，这些涡旋过程可能参与这些深部边界流的位涡动力学。反模式和高分辨率区域海洋模式的结果将被用来发展一种理想化的理论模式和对深部东部边界流的理解。这项拟议的研究还将审查全球耦合模式中对深部东部边界流的模拟，以及它们对气候模式模拟不佳的后果？大尺度动态和未来气候预测。虽然深部东部边界流与上升流系统中的上层海洋潜流完全不同，但这项研究将受益于对这种潜流所做的工作，有助于确定相关的动力学过程。它们包括：β效应、风旋度、底斜率、产生和消散Rossby波的次中尺度涡旋、涡旋-地形相互作用、上梯度涡动动量通量、位涡流入条件、由次中尺度涡旋和垂直混合过程产生的位涡输送和混合、次中尺度和准地转中尺度涡旋对深层层结的影响，以及与内部地形有关的纬向洋流输送东部深部边界流。

Evidence for substantial deep eastern boundary currents emerges repeatedly from observational studies in all southern hemisphere ocean basins. The core of these poleward flows carries a significant component of the meridional overturning circulation. These deep poleward flows occur in some areas well beneath upwelling systems characterized by an equatorward surface current and a poleward undercurrent. These flows affect the Southern Ocean water mass configuration and are an important part of the deep general circulation. Yet their dynamics are not well understood, and they are either poorly represented or not represented at all in climate models. This study will be the first attempt to understand the dynamics of deep eastern boundary currents and their consequences to climate simulation and projections. The project includes training of two graduate students, one postdoctoral researcher, and outreach to the public via the World Wide Web.This project studies deep eastern boundary currents using an analysis of varied observations, a Bayesian inverse model, and a high resolution regional ocean model. The high resolution ocean model can resolve mesoscale and submesoscale eddy processes that may participate in the potential vorticity dynamics of these deep boundary currents. The results of the inverse model and high resolution regional ocean model will be used to develop an idealized theoretical model and understanding of deep eastern boundary currents. The proposed study will also examine the simulation of deep eastern boundary currents in global coupled models, and the consequences of their poor simulation on the climate models? large scale dynamics and future climate projections. While deep eastern boundary currents are completely distinct from upper-ocean undercurrents in upwelling systems, this study will benefit from work done on such undercurrents, helping identify relevant dynamical processes. These include: beta effect, wind curl, bottom slope, submesoscale eddies generating and dissipating Rossby waves, eddy-topography interactions, up-gradient eddy momentum fluxes, potential vorticity inflow conditions, potential vorticity transport and mixing by submesoscale eddies and by vertical mixing processes, submesoscale and quasi-geostrophic mesoscale eddy effects on the deep stratification, and interior topography-related zonal ocean flows feeding deep eastern boundary currents.