A Crossroads of the Atlantic Meridional Overturning Circulation: The Charlie-Gibbs Fracture Zone

大西洋经向翻转环流的十字路口：查理-吉布斯断裂带

• 批准号: 0926656
• 负责人: Amy Bower
• 金额: $ 291.38万
• 依托单位: Woods Hole Oceanographic Institution
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-10-01 至 2015-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0926656&HistoricalAwards=false
• 关键词: Crossroads; Atlantic; Meridional; Overturning; Circulation

Intellectual Merit: Recently the oceanographic community has agreed that we should work quickly to advance our understanding of the Atlantic Meridional Overturning Circulation (AMOC) in recognition of its importance in Earth's climate system. While intense observational effort has been made to describe the basic structure and (in some cases) low-frequency variability at a few locations along the paths of the AMOC, relatively little attention has been paid to the Charlie-Gibbs Fracture Zone (CGFZ), a gateway for both the warm and cold limbs of the AMOC over the Mid-Atlantic Ridge. The result is an incomplete description of even the most fundamental characteristics of this exchange flow. This project presents a combined observational and modeling study of the AMOC at the CGFZ. The primary objectives are:(1) to obtain an improved direct estimate of the mean and low frequency variability of the deep westward transport of Iceland-Scotland Overflow Water through the CGFZ, and(2) to gain a better understanding of the causes of the low-frequency variability in the transport of overflow waters through the CGFZ, especially of the role of the NAC in generating this variability.An array of eight current meter and hydrographic moorings will be installed across the CGFZ that will measure the currents and water properties between the bottom and 500 m for two years beginning in 2010. This array will provide the first long-term, simultaneous observations of both the westward and eastward flows over the CGFZ. An exploratory study of diapycnal mixing intensity in the CGFZ will also be conducted. The modeling component of the proposed work will be idealized in order to address basic dynamical questions about how baroclinic, energetic flows are partitioned between one or more narrow gaps in mid-ocean ridges. The connection between model and data will be made through the phenomenology of interest, i.e., the space and time scales of the variability and the coupling in both the vertical over a single gap and meridionally between gaps.Broader Impacts: By providing an improved understanding of the strength and variability of the warm and cold limbs of the AMOC where they cross over the Mid-Atlantic Ridge, the research will help to sort out the ocean's role in global climate and provide a transport benchmark for critical evaluation of climate models. This project will also contribute to the scientific literacy of blind and visually impaired middle and high school students through a continuing collaboration with the Perkins School for the Blind in Massachusetts. The primary objectives of this effort are to stimulate interest in the earth sciences through face-to-face and online interaction with a working researcher who shares the students' particular disability and to develop accessible physical and virtual tools for teachers of the visually impaired to use with students at Perkins and in the Massachusetts public schools.

知识分子的优点：最近，海洋学界已经同意，我们应该迅速努力，以促进我们对大西洋子午倾覆流通（AMOC）的理解，以表彰其在地球气候系统中的重要性。尽管已经做出了强烈的观察努力来描述基本结构，并且（在某些情况下）沿AMOC路径的几个位置的低频可变性（在AMOC路径的几个位置）对Charlie-Gibbs骨折区（CGFZ）（CGFZ）的关注很少，这是中型山脊中amoc的温暖和冷肢的网关。结果是对这种交换流的最基本特征的不完整描述。该项目提出了CGFZ的AMOC的合并观察和建模研究。主要目标是：（1）获得对冰岛 - 苏格兰深处向西运输的平均和低频率可变性的改进，以及（2）更好地理解低频变异性的原因，使其通过CGFZ的流通量越来越多。从2010年开始，将测量底部至500 m之间的电流和水性质的CGFZ。该阵列将提供对CGFZ上方和向东流的第一长期，同时观察。还将对CGFZ中的Diapynal混合强度进行探索性研究。为了解决有关如何在中端山脊中的一个或多个狭窄间隙之间分区的基本动力学问题，将理想化所提出的工作的建模组成部分。模型和数据之间的联系将通过感兴趣的现象学，即可变性的空间和时间尺度以及在差距之间的垂直方面和垂直之间的耦合的空间和耦合之间的关系。BOADER的影响：通过提供对整体境地的跨度和寒冷的范围的改善，可以改善对摩托群体的影响，从而使一位crese虫的境地跨越一位循环，以帮助一位循环的循环，从而使人们能够跨越一无所知。运输基准，用于对气候模型的批判性评估。该项目还将通过与马萨诸塞州的珀金斯盲人学校的持续合作来促进盲人和视力障碍中学和高中生的科学素养。这项努力的主要目标是通过面对面和在线互动与工作研究人员进行在线互动激发对地球科学的兴趣，该研究人员分享了学生的特殊残疾，并为与Perkins和Massachusetts公立学校使用的视觉障碍的老师开发了可访问的物理和虚拟工具。