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被认识到，但解决其变异性和动力学的地下观测是有限的。了解当前气候条件下的墨西哥湾流动力学是至关重要的第一步，该研究将为进一步了解墨西哥湾流的精细结构、动力学和稳定性做出重要贡献，并可能为其他盆地的西部边界流提供线索。对地下湾流结构和变化的估计将作为建模工作的目标。该计划的观测结果将在接近实时的情况下用于已证明影响的操作数值模型。在此项目中收集的墨西哥湾流内的生物和物理测量数据可能会为跨学科研究提供机会。推广和教育活动将包括参与伍兹霍尔海洋研究所已建立的本科生暑期项目，通过麻省理工学院-伍兹霍尔海洋研究所联合项目将新发现纳入研究生教学，并在公共活动中展示研究成果和水下滑翔机。该项目将培训和支持一名研究生。在为期一年的成功试点研究的基础上，该项目将使用自主水下滑翔机在佛罗里达州南部和新英格兰之间的墨西哥湾流中收集高分辨率的温度、盐度、洋流和生物指标，为期两年。在实地项目结束时，在三年的时间里，将对上游1000米的大约150个横贯墨西哥湾流进行史无前例的取样，这将为研究墨西哥湾流的精细尺度结构和动态提供一个独特的机会。该项目将重点关注1)墨西哥湾流结构的季节性和沿流变化，包括潜在涡度和对稳定性的影响；(2)墨西哥湾流流经哈特拉斯角上游大陆边缘时形成的大振幅内波和厚底混合层；3)利用沿等压轴温度、盐度和位涡量作为被动示踪剂量化水平搅拌的影响。这项研究将促进未来对西方边界流及其在地球气候系统中的作用的理解的理论和分析的进展。

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.