Observation and analysis of the circulation off the northwest coast of Greenland
Date
2011
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
University of Delaware
Abstract
During the months of July and August in 2003, data were collected aboard the USCGC Healy from a shipboard acoustic Doppler current profiler (ADCP) and several conductivity-temperature-depth (CTD) stations as a part of the Canadian Archipelago Throughflow Study between Greenland and Ellesmere Island. This study details findings specifically within an area located south of Smith Sound, near the coast of Thule, Greenland. The West Greenland Current (WGC) carries relatively warm, saline water north into Baffin Bay through Davis Strait. Bourke et al. (1989) suggest that while the majority of the current follows the 500 m isobath and turns cyclonically in northern Baffin Bay, an indeterminate amount continues into the southern part of Smith Sound. Hydrographic and velocity data are used to verify the existence of the WGC in the study area. A synoptic, snapshot view of velocity and hydrography fields along the north-western coast of Greenland is analyzed. After removal of the dominant tidal signal from the measured velocity data, volume and freshwater fluxes through the sections are calculated. In addition, vertical velocity shear is determined using the thermal wind balance and measured density fields. Geostrophic velocity calculations are used to find volume flux and this is compared to the volume flux found using measured ADCP velocity data to further examine the nature of the flow through this region. Furthermore, a buoyancy-driven coastal current is observed that flows in the direction of Kelvin wave propagation. This coastal current is characterized by max- imum velocities greater than 30 cm s-1and is observed at all latitudes examined in this study. Salinity gradients across the section and throughout the water column suggest that freshwater runoff from Greenland is the source of the current.