Dynamics of an idealized Beaufort Gyre : 1. The effect of a small beta and lack of western boundaries
MetadataShow full item record
The Beaufort Gyre in the Arctic Ocean differs from a typical moderate-latitude gyre in some major aspects of its dynamics. First, it is located in a basin without a western boundary, which is essential for closing midlatitude circulations. Second, the gradient in Coriolis parameter, β, is small and so the validity of the Sverdrup balance is uncertain. In this paper, we use an idealized two-layer model to examine several processes that are related to these two issues. In a circular basin with closed geostrophic contours in interior, the variability of vorticity in the upper layer is dominated by eddies. But in the time-mean circulation, the main dynamical balance in the basin's interior is between the curl of wind stress and the eddy vorticity fluxes. The torque of friction becomes important along the boundary where the rim current is strong. It is found that the smallness of β has only a relatively small impact in a circular basin without a meridional boundary. The gyre is considerably more sensitive to the existence of a meridional boundary. The time-mean circulation weakens considerably when a peninsula is inserted between the model's center and the rim. (One side of the peninsula is dynamically equivalent to a midlatitude western boundary.) The gyre's sensitivity to β has also increased significantly when a meridional boundary is present. Subsurface ridges have similar effects on the gyre as a boundary, indicating that such topographic features may substitute, to some extents, the dynamical role of a western boundary.
Author Posting. © American Geophysical Union, 2016. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Oceans 121 (2016): 1249–1261, doi:10.1002/2015JC011296.
Suggested CitationJournal of Geophysical Research: Oceans 121 (2016): 1249–1261
Showing items related by title, author, creator and subject.
Pickart, Robert S. (American Geophysical Union, 2004-04-24)Historical hydrographic and current meter data are used to investigate the properties and circulation at the shelf edge of the Alaskan Beaufort Sea. Thirty-three individual cross-sections, spanning the time period 1950 to ...
Western Arctic Shelf-Basin Interactions Experiment : processing and calibration of moored profiler data from the Beaufort Shelf Edge mooring array Fratantoni, Paula S.; Zimmermann, Sarah; Pickart, Robert S.; Swartz, Marshall (Woods Hole Oceanographic Institution, 2006-12)A high-resolution mooring array was deployed at the edge of the continental shelf in the Beaufort Sea as a part of the western Arctic Shelf-Basin Interactions Program, a multidisciplinary experiment that was designed to ...
Okkonen, Stephen R.; Ashjian, Carin J.; Campbell, Robert G.; Maslowski, Wieslaw; Clement-Kinney, Jaclyn L.; Potter, Rachel (American Geophysical Union, 2009-06-27)Wind-driven changes in the path of warm Bering/Chukchi waters carried by the Alaska Coastal Current (ACC) through Barrow Canyon during late summer are described from high-resolution hydrography, acoustic Doppler current ...