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

[0241354]建议的研究将建立对北大西洋深水向低纬度输出的机制和速率的理解，以及不同的深水流量与上层海洋环流的关系。这些知识将有助于阐明海洋对海气交换变化的反应，并最终阐明海洋在全球气候变化中的作用。西北大西洋中纬度地区的翻转环流包括墨西哥湾暖流向极地输送暖水和较冷的中深水向赤道流动。对全球洋流系统的这些分支及其相关的区域环流如何在年代际时间尺度上变化的理解是不完整的。限制了理解的进展是缺乏长期的、分辨率高的记录来记录水性质、分层和深西部边界流（DWBC）系统的年际信号。重要的是，在亚极纬度产生的异常可能会被墨西哥湾流深刻地改变甚至阻断。相反，亚极异常可能影响气流的位置、强度和/或稳定性，进而影响整个北大西洋的海气交换模式。该项目将记录墨西哥湾流交叉点上游DWBC的温度、盐度、示踪剂和速度变化，方法是在伍兹霍尔以南的斜坡上保持一个系泊阵列，并每半年沿着这条线占据一个水文剖面。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。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分辨年际信号（以及用于海岸示踪分析的回水样本）。除了原始观测外，还将生产和分发增值产品，如核心性质的时间序列和水团运输。同样重要的是，该项目将探索我们提出的阵列的一个子集是否为su？客户对该地区的水性质和输送变化进行索引，为建立长期海洋观测系统奠定基础。所提出的观察将探索和测试关于深西部边界流和墨西哥湾流相互作用的理论观点。参加物理海洋学导论课程的研究生将参与拟议的巡航，向他们介绍观测海洋学。此外，该计划将支持一名博士生，其论文研究将侧重于获得的数据。所有的观察结果和结果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项目中使用它们。

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.