Analyzing the Tropical Impact of a Subpolar Thermohaline Anomaly

Woods Hole Oceanographic Institution, Woods Hole MA

Investigators

Abstract

0095057/Curry In 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.