Role of Mesoscale Eddies in Ventilation of the Southern Ocean

中尺度涡旋在南大洋通风中的作用

• 批准号: 1060163
• 负责人: Igor Kamenkovich
• 金额: $ 62.03万
• 依托单位: University of Miami
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-04-01 至 2015-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1060163&HistoricalAwards=false
• 关键词: Role; Mesoscale; Eddies; Ventilation; Southern

The Southern Ocean and its interactions with the atmosphere play an important role in the ocean and climate dynamics. The processes that govern the communication between the surface and the interior of the Southern Ocean ("ventilation") remain, however, poorly understood. A major challenge comes from the essential and complex role of mesoscale eddies. The spatial distribution of the eddy transports is complicated, and the effects of eddies are incredibly rich. The importance of this complexity has not been systematically evaluated.The main goal of this project is to analyze the role of mesoscale eddies in ventilation of the upper waters (top 2000 meters) of the Southern Ocean. The importance of such properties of the eddy transports as large-scale spatial variations, anisotropy, transport barriers, advection by coherent vortices and non-diffusive effects will be investigated. The main hypothesis is that eddies and their properties listed above play an important role in ventilation of the Southern Ocean. To that effect, an analysis of how ventilation is directly affected by eddies, by studying the importance of eddies in the distribution of passive tracers (idealized and Chlorofluorocarbons) will be undertaken.Specific objectives are to: (i) analyze distributions of the eddy flux divergences and eddy diffusivities, and study their relationship to other physical processes; (ii) examine the importance of eddies for ventilation of the major water masses of the upper Southern Ocean; (iii) identify specific properties of eddy transports, such as their anisotropic structure, that are the most important for the ventilation of the Southern Ocean. These objectives will be achieved using a suite of numerical experiments that are carefully designed to isolate the direct effects of eddies. In particular, the method of analyzing offline simulations with prescribed advective velocities with and without eddies will enable the investigators to isolate and analyze the effects of eddies on ventilation of the Southern Ocean.Intellectual Merit: This project is addressing the fundamentally important problem of the role of eddies in ventilation the Southern Ocean. The proposed research is based on a technique that allows the investigators to most accurately isolate the direct effects of eddies on tracer distributions and ventilation. For the first time, the significance of these effects can be examined quantitatively. Main effects of eddies on distribution of idealized passive tracers and CFCs can be expected to be applicable to dynamically active tracers, such as density and potential vorticity. The progress in understanding the latter effects is notoriously challenging and will greatly benefit from the proposed analysis.Broader Impacts: Understanding and quantifying the role of eddies in developing the mixing history of Southern Ocean waters has important implications for exchange and export of gases (Chlorofluorocarbons, Carbon Dioxide, Oxygen) and nutrients between the Southern Ocean and the rest of the global oceans. The identification of the most important eddy effects that require accurate representation in models will benefit the modeling community. Finally, this project will aid in the interpretation of observational data sets and in the planning of future observational strategies In terms of education and training, a post-doctoral fellow will advance his understanding of processes that govern ventilation of the oceans and redistribute transient oceanic tracers, and will learn various techniques of quantitative analysis of numerical simulations and their comparisons with data. One of the investigators is involved in several outreach activities for an under-represented group in science: women. She has served on the Mentoring Physical Oceanography Women to Increase Retention (MPOWIR) steering committee, participated in two Pattullo Conferences, and leads an MPOWIR mentoring group. She is also on the Steering Committee for the University of Miami's NSF-Advance program.

南大洋及其与气氛的相互作用在海洋和气候动态中起着重要作用。然而，控制了南洋表面和内部之间的通信（“通风”）的过程仍然很少理解。主要挑战来自中尺度涡流的基本和复杂的作用。涡流运输的空间分布很复杂，并且涡流的影响非常丰富。这种复杂性的重要性尚未系统地评估。该项目的主要目的是分析中尺度涡流在南海洋上海水（前2000米）通风中的作用。将研究涡流传输的这种特性的重要性，例如大规模空间变化，各向异性，运输屏障，相干涡流的对流和非排除效应。主要假设是涡流及其特性在南大洋的通风中起着重要作用。为此，将进行涡流在被动示踪剂分布中的重要性（理想化和氯氟氯甲苯）中对通气的直接影响分析。特异性目标是：（i）分析涡流散布差异和eddy差异的分布，以及埃迪差异的分布以及其他物理过程，以及其他物理过程，以及其他物理过程； （ii）检查涡流对南部大洋主要水质量的通风的重要性； （iii）确定涡流的特定特性，例如它们的各向异性结构，这对于南大洋的通风最重要。这些目标将使用一套数值实验来实现，这些实验经过精心设计，以隔离涡流的直接影响。特别是，分析具有有或没有涡流的规定对流速度的离线模拟的方法将使研究人员能够隔离和分析涡流对南部海洋通风的影响。智能优点：该项目正在解决涡流在南部海洋中的涡流作用的根本重要问题。拟议的研究是基于一项技术，该技术使研究人员能够最准确地隔离涡流对示踪剂分布和通风的直接影响。第一次可以定量检查这些效果的重要性。涡流对理想化的被动示踪剂和CFC的分布的主要影响可以预期适用于动态活跃的示踪剂，例如密度和潜在涡度。理解后者效应的进展是众所周知的挑战，并且将从拟议的分析中受益匪浅。BROADER的影响：理解和量化涡流在发展南方海水的混合历史中的作用具有重要意义，这对气体的交换和出口（氯氟碳，二氧化碳，氧化碳，牛根，牛根）和南方海洋和全球范围之间的贸易及其RESACE之间的含义具有重要意义。在模型中需要准确表示的最重要涡流的识别将使建模社区受益。最后，该项目将有助于解释观察数据集以及在教育和培训方面的未来观察策略的计划中，一名博士后研究员将提高他对管理海洋通风的过程的理解，并重新分配瞬态海洋式示踪剂，并将学习对数据和比较数据的数字模拟的定量模拟分析的各种技术。其中一名调查人员参与了一个不足代表的科学群体的宣传活动：妇女。她曾在指导的物理海洋学妇女中任职，以增加保留率（MPOWIR）指导委员会，参加了两个帕图洛会议，并领导了一个Mpowir指导小组。她还是迈阿密大学NSF促进计划的指导委员会。