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

合作研究：东部深海边界流从局部亚尺度位涡动力学对全球气候的影响

• 批准号: 1535800
• 负责人: Eli Tziperman
• 金额: $ 31.7万
• 依托单位: Harvard University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-01 至 2020-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1535800&HistoricalAwards=false
• 关键词: Collaborative; research; Deep; eastern; ocean

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.

在南半球所有海洋盆地的观测研究中，反复出现大量东部深边界流的证据。这些向极地流动的核心承载着经向翻转环流的重要组成部分。这些深层的向极地流发生在上升流系统下方的一些区域，其特征是向赤道的表面流和向极地的暗流。 这些流量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，它们在气候模型中要么没有得到很好的体现，要么根本没有得到体现。 这项研究将是了解东部边界流动力学及其对气候模拟和预测的影响的首次尝试。该项目包括培训两名研究生、一名博士后研究员，并通过万维网向公众进行宣传。该项目通过对各种观测结果的分析、贝叶斯逆模型和高分辨率区域海洋模型来研究东部深边界流。 高分辨率海洋模型可以解析可能参与这些深边界流的位涡动力学的中尺度和亚中尺度涡流过程。反演模型和高分辨率区域海洋模型的结果将用于开发理想化的理论模型和对东部深边界流的理解。拟议的研究还将研究全球耦合模型中东部深边界流的模拟，以及它们对气候模型的不良模拟的后果？大尺度动态和未来气候预测。 虽然东部深边界流与上升流系统中的上层海洋暗流完全不同，但这项研究将受益于对此类暗流所做的工作，帮助识别相关的动力过程。这些包括：贝塔效应、风卷曲、底部坡度、产生和消散罗斯贝波的亚中尺度涡流、涡流地形相互作用、上升梯度涡动量通量、位涡流入条件、亚中尺度涡流和垂直混合过程的势涡传输和混合、亚中尺度和准地转中尺度涡流对深层分层以及与内部地形相关的纬向海洋流的影响供给东部边界深海流。