Coherence of western boundary pressure at the RAPID WAVE Array : boundary wave adjustments or Deep Western Boundary Current advection?
Toole, John M.
MetadataShow full item record
KeywordAtlantic Ocean; Boundary currents; Meridional overturning circulation; Pressure; Waves, oceanic; In situ oceanic observations
This study investigates the coherence between ocean bottom pressure signals at the Rapid Climate Change programme (RAPID) West Atlantic Variability Experiment (WAVE) array on the western North Atlantic continental slope, including the Woods Hole Oceanographic Institution Line W. Highly coherent pressure signals propagate southwestward along the slope, at speeds in excess of 128 m s−1, consistent with expectations of barotropic Kelvin-like waves. Coherent signals are also evidenced in the smaller pressure differences relative to 1000-m depth, which are expected to be associated with depth-dependent basinwide meridional transport variations or an overturning circulation. These signals are coherent and almost in phase for all time scales from 3.6 years down to 3 months. Coherence is still seen at shorter time scales for which group delay estimates are consistent with a propagation speed of about 1 m s−1 over 990 km of continental slope but with large error bounds on the speed. This is roughly consistent with expectations for propagation of coastally trapped waves, though somewhat slower than expected. A comparison with both Eulerian currents and Lagrangian float measurements shows that the coherence is inconsistent with a propagation of signals by advection, except possibly on time scales longer than 6 months.
Author Posting. © American Meteorological Society, 2013. 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 43 (2013): 744–765, doi:10.1175/JPO-D-12-067.1.
Showing items related by title, author, creator and subject.
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 ...
Hydrographic data from Endeavor 223 : formation and spreading of the shallow component of the North Atlantic deep western boundary current McKee, Theresa K.; Pickart, Robert S.; Smethie, William M. (Woods Hole Oceanographic Institution, 1995-05)In March-April, 1991, a 34-day hydrographic cruise aboard R/V Endeavor was undertaken to investigate the formation of the shallow component of the North Atlantic Deep Western Boundary Current (DWBC). Forty-seven stations ...
Palter, Jaime B.; Lozier, M. Susan; Lavender, Kara L. (American Meteorological Society, 2008-05)Labrador Sea Water (LSW), a dense water mass formed by convection in the subpolar North Atlantic, is an important constituent of the meridional overturning circulation. Understanding how the water mass enters the deep ...