Transport Pathways in the North Atlantic: Searching for Throughput

本研究旨在通过绘制经向翻转环流上肢和下肢的交换路径来阐明副热带和副极地北大西洋的连通性。 这项工作的部分动机是欧拉输运估计与 MOC 上肢和下肢的浮子和漂流者行为之间的差异。 这项工作将利用过去 40 年来不同项目积累的广泛拉格朗日数据集，以及历史水文数据和测高海面高度。 基于数据的分析将通过数值模型得到增强。 通过将障碍物与位涡场进行比较，可以深入了解运动学和动力学之间的关系。 最后，应该能够更好地了解翻转环流上肢和下肢水域的停留时间。副极地和副热带北大西洋之间的连通性构成了全球海洋环流和气候系统的重要组成部分。 由于上层海洋和深海中热量和碳的经向输送在很大程度上取决于这些环流之间的联系，因此更好地了解这种复杂的联系将有助于气候变化的预测。 整个物理海洋学界也可以从本文描述的动力系统技术的优点和缺点的说明中受益。 它们过去曾应用于较小规模的流动和盆地规模流动的理想化，但从未应用于北大西洋风驱动环流和 MOC 规模和复杂性的流场。

This study aims to clarify the connectivity of the subtropical and subpolar North Atlantic by mapping exchange pathways for the upper and lower limbs of the meridional overturning circulation. The work is motivated in part by discrepancies between Eulerian transport estimates and the behavior of floats and drifters in the upper and lower limbs of the MOC. The work will take advantage of the extensive Lagrangian data set that has accumulated from different programs over the past 40 years, as well as of historical hydrographic data and altimetric sea surface heights. The data-based analysis will be augmented by numerical models. Insights into the relationship between kinematics and dynamics will result from comparisons of barriers with the potential vorticity field. Finally, an improved understanding of residence times for the waters comprising the upper and lower limbs of the overturning circulation should be forthcoming.The connectivity between the subpolar and subtropical North Atlantic constitutes an important piece of the global ocean circulation and climate system. Because the meridional transport of heat and carbon in both the upper and deep ocean depends crucially on the linkage between these gyres, predictions of climate change will benefit from a better understanding of this complex link. The physical oceanographic community at large may also benefit from an illustration of the strengths and weaknesses of the dynamical systems techniques described herein. They have been applied to smaller scale flows and to idealizations of basin scale flows in the past, but never to a flow field of the scale and complexity of the North Atlantic wind-driven gyres and MOC.