Temporal Variability of the Labrador Current Pathways Around the Tail of the Grand Banks at Intermediate Depths in a High-Resolution Ocean Circulation Model
Temporal Variability of the Labrador Current Pathways Around the Tail of the Grand Banks at Intermediate Depths in a High-Resolution Ocean Circulation Model
复制标题
DOI：
10.1029/2022jc018756
复制
发表时间：
2023-03-01
影响因子：
3.6
通讯作者：
Fratantoni, Paula
中科院分区：
文献类型：
--
作者：
Neto, Afonso Goncalves;Palter, Jaime B.;Fratantoni, Paula
在过去十年中，西北大西洋大陆架和斜坡急剧变暖，改变了海洋生物，挑战了渔业管理。2009/2010年的一次快速变暖事件与拉布拉多海冷水供应的减少有关，将该地区推向了一个前所未有的高温新状态，这种高温一直持续到今天。然而，一个机械的理解如何拉布拉多电流连接减少在纽芬兰大银行的尾巴一直缺乏。在这里，我们提出了一个25年（1993年至2017年）的拉格朗日分析使用混合坐标海洋模式的结果。合成粒子被释放在附近的拉布拉多电流上游的大银行和跟踪的2-D速度场。我们发现拉布拉多海流可以完全被墨西哥湾流的漩涡和曲折所阻挡，这些漩涡和曲折冲击着沿着大浅滩的陆架断裂。这种阻塞可能发生在大浅滩尾部、上游或下游的许多不同位置，因为拉布拉多海流需要一个畅通的通道才能长距离地继续其路径。在模拟中，拉布拉多海流自2008年以来被阻塞的次数更多，这导致了西北大西洋陆架和陆坡的变暖。这些结果，这是与卫星观测相一致的，可以提供预测的新英格兰和新斯科舍省货架环境可能有助于生态系统管理。
The Northwest Atlantic Shelf and Slope have warmed dramatically in the past decade, changing marine life and challenging fisheries management. A rapid warming event in 2009/2010, linked to a reduced supply of cold water from the Labrador Sea, pushed this region to a new state of unprecedentedly high temperatures that persists today. However, a mechanistic understanding of how the Labrador Current connectivity is reduced at the Tail of the Grand Banks of Newfoundland has been lacking. Here, we present the results of a 25-year (1993-2017) Lagrangian analysis using the HYbrid Coordinate Ocean Model. Synthetic particles were released in the vicinity of the Labrador Current upstream of the Grand Banks and tracked in a 2-D velocity field. We found that the Labrador Current can be completely blocked by Gulf Stream eddies and meanders that impinge on the shelf break along the Grand Banks. This blocking can occur in many different locations at, upstream, or downstream of the Tail of the Grand Banks, since the Labrador Current needs a clear passage over a long distance to continue its path. In the simulation, the Labrador Current has been blocked more often since 2008, which led to the warming of the Northwest Atlantic Shelf and Slope. These results, which are consistent with satellite observations, can provide predictability for the New England and Nova Scotia shelf environments potentially helpful for ecosystem management.