Radiating instability of a meridional boundary current
Hristova, Hristina G.
Spall, Michael A.
MetadataShow full item record
A linear stability analysis of a meridional boundary current on the beta plane is presented. The boundary current is idealized as a constant-speed meridional jet adjacent to a semi-infinite motionless far field. The far-field region can be situated either on the eastern or the western side of the jet, representing a western or an eastern boundary current, respectively. It is found that when unstable, the meridional boundary current generates temporally growing propagating waves that transport energy away from the locally unstable region toward the neutral far field. This is the so-called radiating instability and is found in both barotropic and two-layer baroclinic configurations. A second but important conclusion concerns the differences in the stability properties of eastern and western boundary currents. An eastern boundary current supports a greater number of radiating modes over a wider range of meridional wavenumbers. It generates waves with amplitude envelopes that decay slowly with distance from the current. The radiating waves tend to have an asymmetrical horizontal structure—they are much longer in the zonal direction than in the meridional, a consequence of which is that unstable eastern boundary currents, unlike western boundary currents, have the potential to act as a source of zonal jets for the interior of the ocean.
Author Posting. © American Meteorological Society, 2008. 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 38 (2008): 2294-2307, doi:10.1175/2008JPO3853.1.
Suggested CitationArticle: Hristova, Hristina G., Pedlosky, Joseph, Spall, Michael A., "Radiating instability of a meridional boundary current", Journal of Physical Oceanography 38 (2008): 2294-2307, DOI:10.1175/2008JPO3853.1, https://hdl.handle.net/1912/4061
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 ...