Analysis of the Vema Fracture Zone Exploratory Measurements [VEX] Datasets

[0424076]智力优势：本项目将分析2001-2003年开展的Vema断裂带勘探（VEX）测量项目现场阶段收集的观测数据。Vema断裂带（VFZ）是靠近北纬11度的大西洋中脊的一条深海通道，连接圭亚那和冈比亚盆地，并允许南极底水（AABW）和北大西洋深水（NADW）向东流动。VEX测量的目的是确定VFZ内流动的强度和结构，向VFZ输送水的来源路径，以及裂缝带内垂直混合的强度。在项目的现场阶段，对95个水文测量站进行了采样，并部署了6个系泊点，共18个流速计和3个系泊剖面仪。对VEX数据的完整分析和综合将大大改善通过连接北大西洋两个深海盆地的低纬度断裂带的深海流的图像。这将促进我们对经向翻转环流的深层成分的理解，特别是通过认识到大部分总的顺流发生在断裂带和陡峭地形的限制区域。VFZ流动的描述也将有助于在大规模数值模拟中验证狭窄通道流动的表示。更广泛的影响：在VEX测试和开发阶段之外，首次部署的系泊剖面仪是一种新型仪器，可以分析当前的速度、温度、盐度和压力。同时展示速度和CTD剖面的时间序列对改进运输和混合估计的效用，将有利于未来系泊剖面仪的部署。对VEX数据的分析构成了GAGE/VEX联合程序的一个组成部分。所要求的资金将为一名年轻科学家提供机会，提高她利用各种仪器来源的数据分析海洋学过程的技能。

0424076Intellectual Merit: This project will analyze observations collected during the field phase of the Vema Fracture Zone Exploratory (VEX) Measurement program carried out in 2001-2003. The Vema Fracture Zone (VFZ) is an abyssal passage through the Mid-Atlantic Ridge near 11 degrees N, connecting the Guiana and Gambia Basins and permitting eastward flow of Antarctic Bottom Water (AABW) and North Atlantic Deep Water (NADW). The VEX measurements were directed towards determination of the intensity and structure of the flow in the VFZ, the source pathways delivering waters to the VFZ, and the strength of the vertical mixing within the fracture zone. In the field phase of the project, 95 hydrographic stations were sampled and six moorings with a total of 18 current meters and three moored profilers were deployed. The completed analysis and synthesis of the VEX data will provide a greatly improved picture of the abyssal flow through a low-latitude fracture zone linking two of the North Atlantic abyssal basins. This will advance our understanding of the deep component of the meridional overturning circulation, particularly through the recognition that much of the total diapycnal flow occurs in the restricted areas of fracture zones and steep topography. The description of the VFZ flow will also aid in validating the representation of flow through narrow passages in large-scale numerical simulations. Broader Impacts: The moored profilers deployed during VEX for the first time outside their test and developmental phase, are novel instruments profiling current velocities, temperature, salinity, and pressure. Demonstrating the utility of simultaneous time series of velocity and CTD profiles for improved estimation of transports and mixing will benefit future moored profiler deployments. The analysis of the VEX data forms one component of the joint GAGE/VEX program. The funds requested will provide the opportunity for a young scientist to advance her skills in analyzing oceanographic processes using data from a variety of instrument sources.