Temperature and velocity at a mooring downstream of Denmark Strait (Fig4 in thesis).
Abstract
This study investigates the variability of the Denmark Strait Overflow Water (DSOW) and its interaction with overlying ambient water, focusing on their distinct physical characteristics and implications for regional mixing and transport. DSOW, characterized by colder, faster, and fresher properties with dominant along-stream velocity along the isobaths, contrasts with the warmer, slower, and saltier ambient waters, which propagate westward across isobaths. These layers, delineated by a constructed reference interface layer (LR), exhibit mesoscale variability dominated by a 1.8-day period that accounts for approximately 50% of velocity and temperature fluctuations. Cyclonic and anticyclonic eddies, detected along the reference layer, induce significant vertical isopycnal displacements, alternately elevating and depressing the isopycnals. These mesoscale features may influence the frequent vertical shear instabilities (Ri < 0.25) observed within the DSOW layer, particularly below the reference layer, potentially through changes in stratification and vertical shear. Such instabilities, possibly amplified by high- frequency oscillations linked to mesoscale activity, underscore the complex interplay between eddy dynamics, stratification, and shear-induced mixing, shaping the interactions between DSOW and its surrounding waters.
