Pathways and Properties of Atlantic Waters in the Western Arctic Ocean

从体积上看，大西洋水域（AWs）是流入北冰洋的最大水域。它们形成了主要的地下环北极海洋运输系统，并为内部盆地通风。它们是最大的泛北极海洋热储存库，可以通过斜坡上升流和混合等方式影响上层和海冰。水的循环带着示踪剂和污染物穿过北极，水的泛北极分布为入侵物种提供了一个温暖的走廊。在全球范围内，北极西洋线的改变导致北大西洋溢流，并且是经向翻转环流的高纬度（气候敏感）部分。然而，尽管人们迫切关注北极的变化，但关于北极主要洋流的基本问题仍未得到解答。一般认为存在一个气旋式的、等效正压的泛北极边界流，在地形上沿着斜坡和山脊引导。然而，特别是在北极西部，尽管在过去的几十年里观测量有了很大的增加，但关于这种流动的物理性质、各种可能途径的重要性，或边界流与内部或北极大陆架之间交换过程的量化，仍然很少有出版物得到证实。在一些地区，特别是加拿大盆地内部，对水流方向存在公开的分歧（从观测和模拟两方面来看）。对AW环流的观测描述（特别是关于流动路径和特性的信息）对于验证新兴的AW流驱动机制理论和对地面真实的数值北极和全球模式（其环流模式可能通过调整基本模式参数而逆转）至关重要。在北极剧烈的局部变化时期，我们无法回答关于北冰洋环流的基本物理问题，这阻碍了建模、理论进步和观测计划。因此，在与国家/国际观测、建模和理论合作伙伴的合作下，这项工作将利用自20世纪80年代末以来收集的现有历史水文、系泊和漂流浮标数据，对北极西部的大西洋水循环进行基于观测的综合。该分析将包括几个未充分利用的数据集，并利用双扩散温度-盐度结构特征来追踪水路径的新技术。目标是：(1)确定加拿大盆地大西洋水域的路径和变化，包括边界流和内部流；(2)描述水流的主要特征（例如，水流方向、大小和可变性、垂直和水平结构、地形转向、等深线范围）；(3)研究边界流、内部流和陆架之间的交换过程。

Atlantic Waters (AWs) are volumetrically the largest inflow to the Arctic Ocean. They form the major subsurface circum-arctic oceanic transport system and ventilate the interior basins. They are the greatest pan-arctic reservoir of oceanic heat, which may influence upper layers and the sea-ice, for example through slope upwelling and mixing. Circulation of AW carries tracers and contaminants through the Arctic, and the pan-arctic distribution of AW offers a warm corridor for invasive species. Globally, arctic-modification of AW contributes to the North Atlantic overflows and is a high-latitude (climate-sensitive) part of the meridional overturning circulation. Yet, despite the urgent focus on the changing Arctic, fundamental questions about the major ocean current in the Arctic remain unanswered. It is generally believed there is a cyclonic, equivalent-barotropic pan-arctic boundary current, topographically steered along slopes and ridges. However, especially in the western Arctic, despite a large increase in observations in the last decades, there is still little published confirmation of the physical properties of this flow, the importance of various possible pathways, or quantification of exchange processes between the boundary current and the interior or the arctic shelves. There is open disagreement (both from observations and modeling) about the flow direction in some regions, most notably the interior Canada Basin. An observational description of AW circulation (especially information on flow pathways and properties) is essential for verifying emerging theories of the driving mechanisms of the AW flow and for ground-truthing numerical arctic and global models (whose circulation patterns may be reversed by tuning basic model parameters). At a time of dramatic, topical Arctic change, our inability to answer fundamental physical questions about Arctic Ocean circulation is hindering modeling and theoretical advances and observational planning. Thus, in collaboration with national/international observational, modeling and theoretical partners, this effort will conduct an observationally-based synthesis of the Atlantic Water circulation in the western Arctic, using available historic hydrographic, mooring, and drifting buoy data collected since the late 1980s. The analysis will include several underutilized data sets, and exploit a new technique of tracing water pathways using characteristics of double diffusive temperature-salinity structures. The goals are:(1) to define the pathways and variability of Atlantic Waters in the Canadian Basin, including both the boundary current and the interior flow;(2) to describe key features of flow (e.g., flow direction, magnitude and variability, vertical and horizontal structure, topographic steering, isobath range); and(3) to study exchange processes between the boundary current, the interior and the shelves.