An Overlooked Mechanism for Wind-driven Circulations in Semi-enclosed Marginal Seas

边缘海占据了世界大洋边缘的很大一部分，是人类活动的关键区域，但人们很少注意到观测到的大范围风如何迫使这些区域的水循环。这是这项研究的重点，它使用数值模式(理想化和现实化)来更好地了解风如何迫使边缘海的环流模式，以及这如何影响边缘海和公海之间的质量、热量和淡水交换。了解风是如何推动边缘海域的循环，对于预测渔业、污染扩散、军事活动和航运非常重要。还有与教育和学生发展有关的更广泛的影响。该项目的成果将被纳入伍兹霍尔海洋研究所(WHOI)地球物理流体动力学(GFD)暑期学校的研究生水平课程和讲座。参加世界卫生组织暑期学生研究计划和GFD暑期学校的本科生和研究生将接受数值方法、应用数学和数据分析方面的培训。拟议工作的主要智力价值在于增进对边缘海环流的了解。拟议研究的原创性方面是侧重于通过风应力(而不是风应力旋度)施加压力，以及在广泛的应用中综合理想化和现实化的数值模式。这个问题的起因是在西北太平洋发现了大量的边缘海，但随后的方法旨在深入了解埃克曼输送、地形障碍、边界层和内部气流之间的耦合这一一般性问题，使其适用于所有对风强迫很重要的边缘海。迄今为止，边缘海和公海之间的交换一直被认为是由冲击边缘海的地转流所强迫的。然而，这里讨论的埃克曼输运在穿透界定边缘海的地形屏障方面要有效得多，是一种在边缘海内强迫以及边缘海和开阔海洋之间交换的未被探索的机制。在这项研究中，重点研究了在大尺度风应力的强迫下，Ekman输送如何与边界相互作用，并驱动边界层和盆地尺度的流动。理想化和现实化的数值模型被广泛应用于各种物理构型。理想化的构型允许推断环流如何依赖于边缘海的物理几何形状和强迫，而现实的构型允许将这一知识应用于更完整、更真实的系统。模型结果通过对质量、热量和位势涡度预算的分析来解释。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Marginal seas occupy a large fraction of the World Ocean's margins and are key areas for human activity, yet very little attention has been paid to how the observed large-scale winds force water circulation in these areas. This is the focus of this study that uses numerical models (idealized and realistic) to gain a better understanding of how winds force circulation patterns in marginal seas and how this affects exchanges of mass, heat, and freshwater between marginal seas and the open ocean. Understanding how winds force circulations in marginal seas is important for forecasting fisheries, pollution dispersion, military activity, and shipping. There are broader impacts also related to education and student development. Results from this program will be incorporated into graduate level classes and lectures at the Woods Hole Oceanographic Institution (WHOI) Geophysical Fluid Dynamics (GFD) Summer School. Undergraduate and graduate students participating in the WHOI Summer Student Fellow Program and GFD Summer School will be engaged and trained in numerical methods, applied mathematics, and data analysis.The primary intellectual merit of the proposed work lies in the advancement of knowledge of the circulation in marginal seas. The original aspects of the proposed research are the focus on forcing by wind stress (as opposed to wind stress curl) and in the synthesis of idealized and realistic numerical models over a wide range of applications. The problem is motivated by the numerous marginal seas found along the western North Pacific, but the approach followed is designed to yield insights into the generic problem of the coupling between Ekman transports, topographic barriers, boundary layers, and interior flows, making it applicable to all marginal seas for which wind-forcing is important. To date, the exchange between marginal seas and the open ocean has been viewed as being forced by geostrophic flows impinging on the marginal sea. However, the Ekman transport under consideration here is much more effective at penetrating the topographic barriers that define the marginal sea and is an unexplored mechanism for forcing within the marginal sea and for exchange between the marginal sea and the open ocean. In this study, the emphasis is on how Ekman transports, forced by large-scale wind stress, interact with boundaries and drive both boundary layer and basin-scale flows. Idealized and realistic numerical models are applied to a wide range of physical configurations. The idealized configurations allow for inference of how the circulation depends on the physical geometry of the marginal seas and forcing, while the realistic configurations allow for this knowledge to be applied to more complete, real systems. The model results are interpreted using analyses of mass, heat, and potential vorticity budgets.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.