Investigating the Characteristics and Consequences of Interannual Variations in the Northwest Atlantic's Deep Western Boundary Current

西北大西洋深西边界流年际变化特征及后果研究

• 批准号: 0241354
• 负责人: John Toole
• 金额: $ 371.76万
• 依托单位: Woods Hole Oceanographic Institution
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-07-01 至 2009-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0241354&HistoricalAwards=false
• 关键词: Investigating; Characteristics; Consequences; Interannual; Variations

0241354 TooleThe proposed study will build understanding of the mechanisms and rates of North Atlantic Deep Water export to lower latitudes and the relationships of varying deep water flow to the upper ocean circulation. This knowledge will help clarify the response of the ocean to variations in air-sea exchange and ultimately, the ocean's role in global climate change. The overturning circulation of the Northwest Atlantic Ocean at mid-latitude involves poleward transport of warm water by the Gulf Stream and equatorward flow of colder intermediate and deep waters. Comprehension of how these limbs of the global current system and their associated regional recirculations vary on decadal time scale is incomplete. Limiting advance in understanding is the lack of long, well-resolved records to document interannual signals in water properties, stratification, and transport of the Deep Western Boundary Current (DWBC) system. Importantly, anomalies created at subpolar latitudes may be profoundly altered or even blocked by the Gulf Stream. Conversely, subpolar anomalies may influence the position, strength, and/or stability of the Stream, and in turn affect patterns of air-sea exchange throughout the North Atlantic. This project will document temperature, salinity, tracer, and velocity variations of the DWBC upstream of its Gulf Stream cross-under point by maintaining a moored array over the slope south of Woods Hole, and occupying a hydrographic section along this line semi-annually. The array (named Station W in memory of Val Worthington) will quantify changes in DWBC water properties, stratification (potential vorticity), and transport. The high-spatial-resolution sampling possible from the ship will help verify that the array resolves interannual signals (as well as return water samples for shoreside tracer analyses). In addition to raw observations, value-added products such as time series of core properties and transport by water mass will be produced and distributed. Equally important, the project will explore whether a subset of our proposed array is su?cient to index water property and transport variations in this area, setting the stage for a long-term ocean observing system.The observations proposed will explore and test theoretical ideas about the interaction of the Deep Western Boundary Current and Gulf Stream. Graduate students enrolled in the introductory physical oceanography course will participate on the proposed cruises, introducing them to observational oceanography. Moreover, the program will support one Ph.D. student whose dissertation research will focus on the acquired data. All observations and resulting data products will be expediently made available to the community via the internet with the intention of fostering widespread use of these data so that any member of the community can utilize them in their own research program.

0241354图尔拟议的研究将建立北大西洋深水出口到低纬度的机制和速率的理解和不同的深水流量的关系，以上层海洋环流。这些知识将有助于澄清海洋对海气交换变化的反应，并最终澄清海洋在全球气候变化中的作用。中纬度西北大西洋的翻转环流包括墨西哥湾流向极地输送暖水和向赤道输送较冷的中层和深层沃茨。对全球洋流系统的这些分支及其相关的区域再循环如何在十年时间尺度上变化的理解是不完整的。限制了解的进展是缺乏长期的，良好的解决记录记录的水的性质，分层和运输的深层西部边界流（DWBC）系统的年际信号。重要的是，在副极地纬度产生的异常可能会被墨西哥湾流深刻地改变甚至阻挡。相反，副极地异常可能会影响位置，强度和/或流的稳定性，并反过来影响整个北大西洋的海气交换模式。本项目将通过在伍兹霍尔以南的斜坡上保持系泊阵列，并沿着该线每半年占据一个水文剖面，记录DWBC上游墨西哥湾流交叉点的温度、盐度、示踪剂和速度变化。该阵列（为纪念瓦尔沃辛顿而命名为W站）将量化DWBC水性质、分层（位涡）和输送的变化。从船上可能进行的高空间分辨率采样将有助于验证该阵列是否能够分辨年际信号（以及用于岸边示踪剂分析的返回水样）。除了原始观测外，还将制作和分发核心属性时间序列和水团传输等增值产品。同样重要的是，该项目将探讨我们提出的数组的子集是否是su？该项目有助于为这一地区的水属性和运输变化提供指数，为长期海洋观测系统奠定基础。拟议的观测将探索和测试关于深层西部边界流和墨西哥湾流相互作用的理论想法。参加物理海洋学入门课程的研究生将参加拟议的航行，向他们介绍观测海洋学。此外，该计划将支持一个博士学位。学生的论文研究将集中在所获得的数据。所有观察结果和由此产生的数据产品将通过互联网方便地提供给社区，目的是促进这些数据的广泛使用，以便社区的任何成员都可以在自己的研究计划中使用它们。