Analyzing the Tropical Impact of a Subpolar Thermohaline Anomaly

在20世纪80年代末和90年代初，在北大西洋涛动的持续高相期间，拉布拉多海水（LSW）的来源变得更冷、更新鲜和密度更大。这提供了一个异常信号，可以用来追踪北大西洋深西部边界流（DWBC）向南流动的深水。该项目将分析从热带大西洋及其附近的深西部边界流的一系列剖面收集的数据，包括最近在探索性研究小额赠款下获得的一些数据。目的之一是确定LSW异常信号沿北大西洋西部边界传播的速度。这将提供与海洋经向翻转环流调整有关的气候信号从高纬度传播到低纬度的速度有多快的估计。这是许多气候变化情景中的一个重要参数，可用于测试气候模式的保真度。第二个目的是确定这种异常低位涡通过时对DWBC的动力学影响。

0095057/CurryIn the late 1980s and early 1990s the source of Labrador Sea Water (LSW) became colder, fresher and denser during a persistent high phase of the North Atlantic Oscillation. This provided an anomalous signature which could be used to track deep water as it flows south in the Deep Western Boundary Current (DWBC) of the North Atlantic. This project will analyze data collected from a series of sections across the deep western boundary current in and near the tropical Atlantic, including some that were recently made under a Small Grant for Exploratory Research. One aim is to determine the speed with which the anomalous LSW signal is traveling along the western boundary of the North Atlantic. This will provide an estimate of how rapidly climate signals associated with adjustments in the ocean's meridional overturning circulation can propagate from high to low latitudes. This is an important parameter in many scenarios of climate change and one that can be used to test the fidelity of climate models. A second aim is to determine the dynamical effects on the DWBC of the passage of this anomalously low potential vorticity.