Finescale Structure and Dynamics of the Gulf Stream

虽然墨西哥湾流对全球气候系统的重要性早已得到承认，但解决其变异性和动态的地下观测有限。了解墨西哥湾流在当前气候下的动力学是关键的第一步，这项研究将大大有助于增进对墨西哥湾流精细结构、动力学和稳定性的认识，并可能有助于揭示其他盆地的西部边界流。对次表层墨西哥湾流结构和可变性的估计将作为模拟工作的目标。来自该计划的观测结果将近乎实时地提供，用于业务数值模式，在那里它们已经证明了影响。在该计划期间收集的墨西哥湾流中同时进行的生物和物理测量可能会带来跨学科研究的机会。外展和教育活动将包括参与伍兹霍尔海洋研究所既定的本科生暑期项目，通过麻省理工学院-伍兹霍尔海洋研究所联合计划将新发现纳入研究生教学，以及在公共活动中展示研究和水下滑翔机。该项目将培训和支持一名研究生。在一项为期一年的成功试点研究的基础上，该项目将使用自动水下滑翔机收集两年来对佛罗里达州南部和新英格兰之间的墨西哥湾流内的温度、盐度、洋流和生物指标的高分辨率测量。在实地考察计划结束时，一组史无前例的约150个横跨墨西哥湾流的横断面将在三年的时间里穿过1000米以上的海平面，这将提供一个独特的机会来研究墨西哥湾流的精细尺度结构和动力学。该项目将侧重于1)墨西哥湾流结构的季节和沿流变化，包括位涡和对稳定性的影响；2)当墨西哥湾流流经哈特拉斯角上游大陆边缘时形成的大幅度内波和厚底混合层；以及3)使用沿等高的温度、盐度和位涡作为被动示踪剂来量化水平搅动的影响。这项研究将促进未来在理解西方边界流及其在地球气候系统中的作用方面的理论和分析方面的进展。

While the significance of the Gulf Stream to the global climate system has long been recognized, subsurface observations that resolve its variability and dynamics are limited. Understanding the dynamics of the Gulf Stream under the current climate is a critical first step, and this study will contribute significantly to advancing knowledge of the fine scale structure, dynamics, and stability of the Gulf Stream and may shed light on western boundary currents in other basins. Estimates of subsurface Gulf Stream structure and variability will serve as targets for modeling efforts. Observations from this program will be made available in near-real time for use in operational numerical models where they have demonstrated impacts. Concurrent biological and physical measurements within the Gulf Stream collected during this program are likely to lead to opportunities for interdisciplinary studies. Outreach and education activities will include involvement with established undergraduate summer programs at the Woods Hole Oceanographic Institution, inclusion of new findings in graduate instruction through the Massachusetts Institute of Technology-Woods Hole Oceanographic Institution Joint Program, and showcasing of the research and underwater gliders at public events. The project will train and support one graduate student. Building on a successful 1-year pilot study, this project will use autonomous underwater gliders to collect high-resolution measurements of temperature, salinity, currents, and biological indicators within the Gulf Stream between southern Florida and New England for two years. At the conclusion of the field program, an unprecedented set of approximately 150 cross-Gulf Stream transects through the upper 1000 m over a three-year period will offer a unique opportunity to examine the fine scale structure and dynamics of the Gulf Stream. This project will focus on 1) seasonal and along-stream variability in Gulf Stream structure, including potential vorticity and implications for stability; 2) large-amplitude internal waves and thick bottom mixed layers that are formed when the Gulf Stream flows over the continental margin upstream of Cape Hatteras; and 3) quantifying the effects of horizontal stirring using along-isopycnal temperature, salinity, and potential vorticity as passive tracers. This research will stimulate future theoretical and analytical advances in the understanding of western boundary currents and their role in the Earth's climate system.