Transport and fate of the Labrador Coastal Current

拉布拉多海岸流（LCC）将加拿大北极群岛、哈德逊湾和格陵兰冰盖的新鲜流出物沿纽芬兰和拉布拉多大陆架向南输送。如果在近海混合到次极环流的边界流中，LCC中的淡水有可能使上层海洋分层并改变大西洋经向翻转环流（AMOC）。然而，目前对LCC的运输以及LCC是否与北大西洋大尺度环流相互作用，或者是否仍然停留在大浅滩周围的大陆架上，所知甚少。该项目将研究LCC的命运及其沿加拿大拉布拉多和纽芬兰海岸线的运输。利用欧拉和拉格朗日的联合观测研究，该项目将检验LCC的淡水、浮力是否会离开大陆架，加入拉布拉多洋流，假设是由于该地区复杂的水深测量和强风的共同作用。这项工作将支持一名早期的研究人员，为一名暑期本科生实习生提供项目材料，并让7名有游轮经验的学生担任守望员。四个系泊将在夏季部署，为期一年，沿着加拿大大西洋区监测计划（AZMP）海豹岛的水文剖面靠近汉密尔顿银行，这将提供LCC的第一个连续体积和淡水运输时间序列。此外，46艘水面漂浮器将通过三个系泊的水下自主发射平台（salp）每隔15天向LCC投放一次。在部署和恢复工作中，将进行两次巡航，收集纽芬兰和拉布拉多大陆架的高分辨率船上ADCP和CTD调查。结合历史上的AZMP水文剖面，该项目将量化运输，跟踪LCC淡水的路径和命运，并将确定陆架-盆地交换的热点。NASA地表水和海洋地形（SWOT）卫星发射的时间和三个月的“快速采样阶段”（每天飞越）的时间可能与漂浮物释放的时间一致，并将提供高分辨率的海面高度（SSH）和内大陆架表面地转速度，有可能扩大这一目标研究的时空范围。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The Labrador Coastal Current (LCC) transports fresh outflow from the Canadian Arctic Archipelago, Hudson Bay, and the Greenland Ice Sheet southward along the Newfoundland and Labrador Shelf. If mixed offshore into the boundary current of the subpolar gyre, the fresh water in the LCC has the potential to stratify the upper ocean and alter the Atlantic Meridional Overturning Circulation (AMOC). Yet very little is currently known about the transport of the LCC and whether the LCC interacts with the large-scale North Atlantic circulation, or remains on the shelf around the Grand Banks. This project would study the fate of the LCC and its transport along the Canadian Labrador and Newfoundland coastlines. Using a combined Eulerian and Lagrangian observational study, the project would examine whether the fresh, buoyant water in the LCC moves off the shelf to join the Labrador Current, hypothetically due to a combination of the region’s complex bathymetry and strong wind forcing. The work would support an early career researcher, provide project material for a summer undergraduate intern, and involve 7 students with cruise experience as watch standers.Four moorings will be deployed in summer for one year, along the Canadian Atlantic Zone Monitoring Program (AZMP) Seal Island hydrographic section inshore of Hamilton Bank, which will provide the first continuous volume and freshwater transport time series of the LCC. In addition, 46 surface drifters will be released into the LCC, in subsets at 15 day intervals, by three moored Submerged Autonomous Launch Platforms (SALPs). Two cruises will be conducted along the deployment and recovery efforts, collection high-resolution shipboard ADCP and CTD surveys of the Newfoundland and Labrador Shelf. Together with the historical AZMP hydrographic sections, the project will quantify transport and track the pathways and fate of the fresh water in the LCC, and will identify hot spots of shelf-basin exchange. Timing of the NASA Surface Water and Ocean Topography (SWOT) satellite launch and three-month “Fast- Sampling Phase” with daily flyovers may coincide with the drifter releases, and would provide high-resolution sea-surface height (SSH) and surface geostrophic velocities of the inner shelf, potentially broadening the spatial and temporal extent of this targeted study.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.