On the dynamics and water mass transformation of a boundary current connecting alpha and beta oceans
MetadataShow full item record
KeywordContinental shelf/slope; Baroclinic flows; Boundary currents; Buoyancy; Freshwater; Thermohaline circulation
A subpolar marginal sea, like the Nordic seas, is a transition zone between the temperature-stratified subtropics (the alpha ocean) and the salinity-stratified polar regions (the beta ocean). An inflow of Atlantic Water circulates these seas as a boundary current that is cooled and freshened downstream, eventually to outflow as Deep and Polar Water. Stratification in the boundary region is dominated by a thermocline over the continental slope and a halocline over the continental shelves, separating Atlantic Water from Deep and Polar Water, respectively. A conceptual model is introduced for the circulation and water mass transformation in a subpolar marginal sea to explore the potential interaction between the alpha and beta oceans. Freshwater input into the shelf regions has a slight strengthening effect on the Atlantic inflow, but more prominently impacts the water mass composition of the outflow. This impact of freshwater, characterized by enhancing Polar Water outflow and suppressing Deep Water outflow, is strongly determined by the source location of freshwater. Concretely, perturbations in upstream freshwater sources, like the Baltic freshwater outflow into the Nordic seas, have an order of magnitude larger potential to impact water mass transports than perturbations in downstream sources like the Arctic freshwater outflow. These boundary current dynamics are directly related to the qualitative stratification in transition zones and illustrate the interaction between the alpha and beta oceans.
Author Posting. © American Meteorological Society, 2018. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 48 (2018): 2457-2475, doi:10.1175/JPO-D-17-0186.1.
Suggested CitationArticle: Lambert, Erwin, Eldevik, Tor, Spall, Michael A., "On the dynamics and water mass transformation of a boundary current connecting alpha and beta oceans", Journal of Physical Oceanography 48 (2018): 2457-2475, DOI:10.1175/JPO-D-17-0186.1, https://hdl.handle.net/1912/10675
Showing items related by title, author, creator and subject.
von Appen, Wilken-Jon; Pickart, Robert S.; Brink, Kenneth H.; Haine, Thomas W. N. (2013-10-30)Data from seven moorings deployed across the East Greenland shelfbreak and slope 280 km downstream of Denmark Strait are used to investigate the characteristics and dynamics of Denmark Strait Overflow Water (DSOW) cyclones. ...
Potential vorticity structure in the North Atlantic western boundary current from underwater glider observations Todd, Robert E.; Owens, W. Brechner; Rudnick, Daniel L. (American Meteorological Society, 2016-01)Potential vorticity structure in two segments of the North Atlantic’s western boundary current is examined using concurrent, high-resolution measurements of hydrography and velocity from gliders. Spray gliders occupied 40 ...
Sutherland, David A.; Pickart, Robert S. (2008-03-12)The subtidal circulation of the southeast Greenland shelf is described using a set of high-resolution hydrographic and velocity transects occupied in summer 2004. The main feature is the East Greenland Coastal Current ...