Collaborative Research: An Observational and Modeling Study of the Physical Processes Driving Exchanges between the Shelf and the Deep Ocean At Cape Hatteras

合作研究：对驱动哈特拉斯角陆架和深海之间交换的物理过程的观测和建模研究

• 批准号: 1558521
• 负责人: Robert Todd
• 金额: $ 186.51万
• 依托单位: Woods Hole Oceanographic Institution
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-04-01 至 2022-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1558521&HistoricalAwards=false
• 关键词: Collaborative; Research; Observational; Modeling; Study

Recent unusual conditions along the U.S. East Coast have dramatically demonstrated the importance of understanding the dynamics controlling shelf-deep ocean exchange at the confluence of the North Atlantic gyres near Cape Hatteras. Atypical Gulf Stream position, air-sea heat flux, extremes in ocean temperature, and sea level rise are potential harbingers of larger shifts in atmospheric and oceanic forcing. Effects on shelf-deep ocean exchange are unknown due to incomplete dynamical understanding of the present. Development of predictive capacity is particularly relevant at this time, as oil and gas exploration is being planned. The understanding of shelf-deep ocean exchange gained through this project will be applicable to other regions where shelf and basin-scale currents converge and could improve our capacity to anticipate the response of the coastal ocean to climate change in the coming decades. In addition to the physical interactions between scales and oceanic regions, the relevance of exported shelf waters at Cape Hatteras to global carbon budgets may be large, and is difficult to quantify due to carbon budget mediation by biological ecosystems that vary with season and water mass. Both ecosystems and export processes may change under predicted climatic shifts, so understanding export processes has broad biogeochemical importance. Collaborations with biogeochemists and ecologists will be pursued to utilize the data to study ecosystems in this area of high biological diversity that is home to many commercially important species. Insights gained through the project will also improve mitigation of pollutant spills. The outreach and educational efforts include a public exhibit and talks, opportunities for joining science cruises and participation in the Society of Women Engineers "Girls Engineer It! Day", a daylong event for girls in grades 6-12, and the Wood Hole Oceanographic Institution's summer program for undergraduates from underrepresented groups. The project will support two early career scientists, train one postdoctoral researcher and four graduate students, and give undergraduate students hands-on experience in the operation of the autonomous gliders.Subtropical and subpolar oceanic gyre boundaries are characterized by confluent western boundary currents and convergence in the adjacent shelf and slope waters. Together, they lead to large net export of shelf waters to the deep ocean, and complex, bidirectional shelf-deep ocean exchange, in response to strong forcing typical of mid-latitude western ocean margins. Shelf-deep ocean exchange processes at such dynamic sites remain poorly understood, due in part to the technical challenge of resolving broad ranges of relevant spatial and temporal scales. The understanding gained by investigating the wide seasonal range of parameter space will facilitate exploration of how shelf circulation and shelf-open ocean exchange may evolve due to observed and projected long-term shifts in regional and basin-scale circulation, hydrography, and atmospheric forcing. This project will deploy fixed, mobile, and remote observational platforms in combination with idealized and realistic numerical simulations to investigate exchange processes near Cape Hatteras. The sampling array will provide an observational data set with unprecedented temporal and spatial resolution in a region of large episodic export and exchange. These observations will be used to identify dominant exchange processes; correlate them with observed forcing; define ranges of forcing and shelf response; verify parallel developments within the realistic model framework; and establish causation through detailed assessment of momentum and vorticity balances, integrating observational and validated model products. In addition to physical data, the autonomous gliders will also collect chlorophyll fluorescence, oxygen saturation, and acoustic backscatter data that are of direct relevance to biogeochemical properties exported from the shelf to the deep ocean. These non-physical data will be used as water mass tracers and to portray the structure of the chlorophyll-a and dissolved oxygen at unprecedented resolution.

美国东海岸的最近不寻常的条件极大地证明了在哈特拉斯角附近的北大西洋陀螺汇合处控制货架深海交易所的动态的重要性。非典型的海湾溪流位置，空气热通量，海洋温度的极端和海平面上升是大气和海洋强迫较大变化的潜在防护者。由于对当前的动力学不完全理解，对架子深海交换的影响未知。随着计划探索石油和天然气，预测能力的发展尤其重要。通过该项目获得的对货架深海交易所的理解将适用于货架和盆地尺度电流汇聚的其他地区，并可以提高我们预测未来几十年沿海海洋对气候变化的反应的能力。除了尺度和海洋区域之间的物理相互作用外，哈特拉斯角（Cape Hatteras）的出口货架水与全球碳预算的相关性可能很大，并且由于生物生态系统的碳预算调解而由于随季节和水量而变化而难以量化。在预测的气候变化下，生态系统和出口过程都可能发生变化，因此了解出口过程具有广泛的生物地球化学重要性。将追求与生物地球化学家和生态学家的合作，以利用数据来研究这一高生物学多样性领域的生态系统，这是许多商业上重要物种的所在地。通过该项目获得的见解也将改善污染物溢出的缓解。外展和教育工作包括公开展览和谈判，加入科学巡游的机会以及参加女性工程师协会“女子工程师It！day”，6至12年级的女孩的一天活动以及伍德霍尔海洋学机构为不足的群体提供的暑期夏季计划。该项目将支持两名早期职业科学家，培训一名博士后研究人员和四名研究生，并为本科生提供自主滑翔机运作的动手经验。汇合的西部边界和近极西部边界电流和邻近架子和坡道的融合的海洋和层下式Gyre边界的特征是。它们一起，将大量的架子水域出口到深海，并响应强大的强迫中纬度西部海洋边缘的强大强迫。此类动态场所的货架深海洋交换过程仍然很少理解，部分原因是解决相关空间和时间尺度的广泛范围的技术挑战。通过研究广泛的参数空间范围而获得的理解将有助于探索由于观察到和预计的区域和盆地尺度循环，水文学和大气强迫的长期变化而导致的货架循环和货架开放的海洋交换如何发展。该项目将与理想化和现实的数值模拟结合使用固定，移动和远程观察平台，以调查哈特拉斯角附近的交换过程。采样阵列将在大型偶发出口和交换区域中提供前所未有的时间和空间分辨率的观测数据集。这些观察结果将用于识别主要的交换过程。将它们与观察到的强迫相关联；定义强迫和货架响应的范围；验证现实模型框架内的并行发展；并通过详细评估动量和涡度平衡来建立因果关系，从而整合观察性和经过验证的模型产品。除物理数据外，自动滑翔机还将收集与从架子到深海导出的生物地球化学特性直接相关的叶绿素荧光，氧饱和度和声学反向散射数据。这些非物理数据将用作水质示踪剂，并以前所未有的分辨率描绘叶绿素-A的结构和溶解的氧气。