Physical and Biological Exchange Processes and Lagrangian Pathways of Eel Larvae Between Deep Ocean and Shelf Regions of the Northwestern Atlantic

大陆架或陆坡上的沃茨与近海更深的海洋之间的交换对于了解海洋中的温度、盐度和其他物理、化学和生物水属性的分布是重要的。尽管它们的重要性和大量的以前的研究，这些交换过程没有得到很好的理解。这是因为它们发生在时间和空间的短尺度上，这使得通过现场测量或数值模型来解决它们成为一个挑战。这项全面的研究将利用最先进的现实海洋环流模型，结合新的动力系统工具，以更好地理解和量化这些交流。研究区域将从缅因州湾和中大西洋湾延伸到墨西哥湾流和马尾藻海，那里是美洲鳗鱼的产卵地，美洲鳗鱼是一种具有重大科学意义和经济价值的物种。这种鱼从沿着北美海岸的淡水栖息地到马尾藻海进行了一次引人注目的产卵迁移，然后它的幼虫必须返回主要发生在北美东海岸沿着的沿海苗圃栖息地。由于幼虫只有有限的游泳能力，它们必须通过海洋环流特征来完成迁移。这项研究还将探讨他们如何实现这一非凡的壮举。该项目将支持三名早期职业科学家，并将促进物理海洋学家和生物学家之间的合作。该项目还将为K-12教育计划做出贡献，包括主要针对少数民族学生的班级访问和实地考察。它还将继续努力通过艺术和舞蹈将科学带给公众。这项拟议研究的首要目标是从拉格朗日的角度描述和量化大陆架和公海之间的水团交换和财产流动。 预计有几种物理机制会影响该区域的交换过程。这些包括地形转向、风力、不稳定性和陆架断裂射流的曲折、墨西哥湾流曲折和撞击陆架的环，将对每一项进行调查和量化。拟议研究的具体区域和特征包括中大西洋湾、缅因州湾、斜坡海、墨西哥湾流及其延伸和马尾藻海。一个集中的应用所提出的努力将致力于调查的扩散鳗鱼幼虫作为一个例子，半拉格朗日，生物相关的粒子。这项研究将以一个高分辨率区域模型和一个数据同化全球模型为基础，将欧拉通量估计数与拉格朗日通量估计数进行比较，并将联合收割机传统统计技术与新的动力系统分析相结合。由于其跨学科的性质，该项目将对各个领域产生影响，包括物理海洋学，海洋生物学和动力系统。PI还将与NOAA东北渔业科学中心的同事合作。参与K-12教育计划将包括：（1）与已建立的合作伙伴学校合作，将项目成果引入其地球科学模块;（2）为东波士顿高中（80%为少数民族学生）学生进行课堂参观和实地考察。参与麻省理工学院/世界卫生组织海洋学联合项目的专业人员将把这项研究的结果纳入他们的研究生课程。

Exchange between waters over the continental shelf or slope and the deeper ocean offshore is important for understanding the distribution of temperature, salinity and other physical, chemical, and biological water properties in the ocean. Despite their importance and the extensive number of previous studies, these exchange processes are not well understood. This is because they occur over short scales in time and space, which makes it a challenge to resolve them with field measurements or numerical models. This comprehensive study will make use of state-of-the-art realistic ocean circulation models in combination with novel dynamical system tools to better understand and quantify these exchanges. The study area will extend from Gulf of Maine and the Mid-Atlantic Bight to the Gulf Stream and the Sargasso Sea, which is the spawning site for the American eel, a species of great scientific interest and economic value. This fish undertakes a remarkable spawning migration from freshwater habitats along the North American coast to the Sargasso Sea, and its larvae then have to return to coastal nursery habitats that predominantly occur along the eastern seaboard of North America. Since the larvae have only limited swimming ability, they have to navigate ocean circulation features to complete their migration. This study will also explore how they achieve this remarkable feat. The project will support three early-career scientists and will promote collaboration between physical oceanographers and biologists. The project will also contribute to K-12 educational programs, including class visits and field trips targeting mostly minority students. It will also continue efforts to bring science to the public through art and dance. The overarching goal of the proposed study is to characterize and quantify, from a Lagrangian viewpoint, water mass exchanges and property fluxes between the continental shelf and the open ocean. Several physical mechanisms are expected to influence the exchange processes in this region. These include topographic steering, wind forcing, instabilities and meanders of the shelfbreak jet, and Gulf Stream meanders and rings impinging on the shelf, each of which will be investigated and quantified. Specific regions and features of interest for the proposed study include the Mid-Atlantic Bight, the Gulf of Maine, the Slope Sea, the Gulf Stream and its extension, and the Sargasso Sea. A focused application of the proposed effort will be devoted to investigating the dispersal of eel larvae as an example of semi-Lagrangian, biologically relevant particles. The study will be based on a high-resolution regional model and a data-assimilative global model, and would compare Eulerian flux estimates with their Lagrangian counterparts and combine conventional statistical techniques with novel dynamical systems analysis. By its interdisciplinary nature, this project will have impacts across a variety of fields, including physical oceanography, marine biology, and dynamical systems. The PIs will also collaborate with colleagues at the NOAA Northeast Fisheries Science Center. Participation in K-12 educational programs will include (1) efforts with established partner schools to introduce project results into their earth science module, and (2) class visits and field trips for East Boston High School (80% minority students) students. PIs participating in the MIT/WHOI Joint Program in Oceanography will incorporate the study's findings into their graduate courses.