Synoptic sections of the Denmark Strait Overflow

• Published in: Geophysical Research Letters
• Main Authors: Girton, J. B., Sanford, T. B., Käse, Rolf H.
• Format: Article in Journal/Newspaper
• Language: English
• Published: AGU (American Geophysical Union) 2001
• Subjects: Arctic; Denmark Strait
• Online Access: https://oceanrep.geomar.de/id/eprint/1949/; https://oceanrep.geomar.de/id/eprint/1949/1/Girton01_grl.pdf; https://doi.org/10.1029/2000GL011970

We report on a rapid high-resolution survey of the Denmark Strait overflow (DSO) as it crosses the sill, the first such program to incorporate full-water-column velocity profiles in addition to conventional hydrographic measurements. Seven transects with expendable profilers over the course of one week are used to estimate volume transport as a function of density. Our observations reveal the presence of a strongly barotropic flow associated with the nearly-vertical front dividing the Arctic and Atlantic waters. The seven-section mean transport of water denser than σθ=27.8 is 2.7±0.6Sv, while the mean transport of water colder than 2.0°C is 3.8±0.8 Sv. Although this is larger than the 2.9 Sv of θ < 2°C water measured by a 1973 current meter array, we find that a sampling of our sections equivalent to the extent of that array also measures 2.9Sv of cold water. Both the structure and magnitude of the measured flow are reproduced well by a high-resolution numerical model of buoyancy-driven exchange with realistic topography.