Collaborative Research: Exchange and Dispersion Across the Inner Shelf: Understanding the Importance of Spatial Variability

本研究旨在了解大陆架内部流场的空间变化，尺度为100米到10公里，其对交换和扩散的贡献，以及对沿海系统的影响。最近的观察玛莎葡萄园岛南部的沿海海洋，MA记录了惊人的例子，空间可变的流量有可能推动集中横向交换整个货架相媲美，由于经常检查沿货架统一响应上升流或下降流。 然而，我们几乎不知道在这些尺度的流场的特性，因为传统的观测技术和典型的现实货架模型不足以解决这些尺度。这将可能是第一次全面研究目前的变化，在沿海海洋的规模从100米到10公里的高分辨率高频雷达表面电流，密集的观测地下速度和水文，以及大规模漂流物释放沿着与比较现实和理想化的数值模型的独特组合。拟议的工作将量化整个大陆架的水团的总通量，在风，分层和测深交换的空间变异性的相对重要性，和空间可变dispersion.Previous努力量化在沿海海洋的交换率的作用一般集中在运输由于沿大陆架均匀，风驱动的动态。虽然在大多数沿海地区发现了由于主要海角或岬、水深不规则或不均匀风场而造成的额外迁移的证据，但这些变异性来源对整个大陆架的交换和扩散的相对影响尚未量化。此外，小规模和/或瞬态功能的影响，潜在的重要来源的空间相关的交换或分散，从来没有得到解决。这种对玛莎葡萄园岛以南沿海海洋交换的全面看法，包括除了基于欧拉的运输研究之外，还使用拉格朗日轨迹分析，将能够捕获更广泛的空间变异性，并将量化瞬态事件的发生，其驱动因素，以及它们对海岸系统的重要性。水团从邻近海岸的浅水沃茨向近海更大的沿海海洋的运动控制着热量、盐分、营养物质和污染物之间的联系。这项工作的结果将通过全面审视跨大陆架迁移，记录空间变异对沿海系统的潜在影响。这一努力将提高我们的能力，以量化和预测对评估沿海地区生产力至关重要的交换，以及对监测有害藻华、污染物和搜救行动的命运至关重要的扩散率。PI积极参与WHOI和UMASS达特茅斯的教学和指导，并与沿海管理者和规划者互动。与NOAA的东北渔业科学中心合作，一项广泛的教育计划将通过额外的漂流部署，将该地区的K-12学生带入科学领域

This study seeks to understand spatial variability in the flow field over the inner part of the continental shelf at scales of 100s of meters to 10s of kilometers, its contribution to exchange and dispersion, and its implications for coastal systems. Recent observations of the coastal ocean south of Martha's Vineyard, MA have documented startling examples of spatially-variable flows with the potential to drive focused lateral exchange across the shelf rivaling that due to the frequently-examined along-shelf uniform response to upwelling or downwelling. Yet, we know almost nothing about the characteristics of the flow field at these scales because conventional observational techniques and typical realistic shelf models do not adequately resolve these scales. This will likely be the first comprehensive study of current variability in the coastal ocean at scales from 100s of meters to 10s of kilometers by employing a unique combination of high-resolution HF radar surface currents, dense observations of subsurface velocity and hydrography, and mass drifter releases along with comparisons to realistic and idealized numerical models. The proposed work will quantify the total flux of water masses across the shelf, the relative importance of spatial variability in the wind, stratification, and bathymetry on exchange, and the role of spatially-variable dispersion.Previous efforts to quantify the rates of exchange in the coastal ocean have generally focused on the transport due to along-shelf uniform, wind-driven dynamics. While evidence of additional transport due to major capes or headlands, bathymetric irregularities, or non-uniform wind fields has been found in most coastal areas, the relative impact of these sources of variability on exchange and dispersion across the shelf have not been quantified. Additionally, the effects of small-scale and/or transient features, potentially important sources of spatially-dependent exchange or dispersion, have never been resolved. This comprehensive view of exchange across the coastal ocean south of Martha's Vineyard, including the use of Lagrangian trajectory analyses in addition to the Eulerian-based transport studies, will enable a much broader range of spatial variability to be captured and will quantify the occurrence of transient events, their drivers, and their importance for coastal systems.The movement of water masses from the shallow waters adjacent to the coast to the larger coastal ocean offshore controls the flux of heat, salt, nutrients, and pollutants between the nearshore and the global ocean. By providing a holistic look at across-shelf transport, the results of this work will document the potential effects of spatial variability on coastal systems. This effort will improve our ability to quantify and predict the exchange critical to assessing the productivity of coastal areas and the dispersion rates critical to monitoring the fate of harmful algal blooms, pollutants, and search and rescue operations. The PIs are actively involved in teaching and mentoring at WHOI and UMASS Dartmouth as well as interacting with coastal managers and planners. In collaboration with the NOAA's Northeast Fisheries Science Center, a broad educational program will entrain K-12 students in the region into the science being conducted through additional drifter deployments