Shelfbreak frontal eddies over the continental slope north of Cape Hatteras
MetadataShow full item record
Shelfbreak and slope eddies have been implicated as important agents in the exchange of water between the shelf and slope domains of the Middle Atlantic Bight (MAB). Here we present temperature, salinity, and velocity data from a series of shipboard transects that intercepted a rich eddy field over the slope of the southern MAB. Attention is focused on a well-sampled cyclonic eddy, of roughly 60-km diameter and 300-m depth, that translated southward at 0.1 m s−1. The eddy was composed of a mix of water masses including MAB shelf and slope water, Gulf Stream water, and water from the MAB shelfbreak front. Gradient Richardson numbers suggest that these water masses were subject to vigorous turbulent vertical mixing. The transport of shelfbreak frontal water contained within the eddy was substantial. In the upper 100 m, shelfbreak frontal water comprised ∼75% of the eddy's volume. This frontal water fraction moved southward with a transport of ∼0.4 Sv, comparable with the volume transport within the shelfbreak frontal jet. A number of factors indicate that this highly energetic eddy, with maximum azimuthal velocity of 0.7 m s−1, was generated through instability of the shelfbreak frontal jet. The eddy had apparently developed rapidly (in <3 days), consistent with models of eddy generation through baroclinic instability of the shelfbreak frontal jet. The eddy's potential temperature/salinity (θ/S) properties and energy density closely matched the θ/S properties and energy density found in the frontal jet to the north of the eddy.
Author Posting. © American Geophysical Union, 2009. 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 114 (2009): C02017, doi:10.1029/2007JC004642.
Showing items related by title, author, creator and subject.
Evaluation of an acoustic remote sensing method for frontal-zone studies using double-diffusive instability microstructure data and density interface data from intrusions Duda, Timothy F.; Lavery, Andone C.; Sellers, Cynthia J. (Elsevier, 2016-10-19)Understanding intrusive exchange at oceanic water mass fronts may depend on building data-constrained models of the processes, but obtaining the needed representative and comprehensive data is challenging. Acoustic imaging ...
Shelf-edge frontal structure in the central East China Sea and its impact on low-frequency acoustic propagation Ramp, Steven R.; Chiu, Ching-Sang; Bahr, Frederick L.; Qi, Yiquan; Dahl, Peter H.; Miller, James H.; Lynch, James F.; Zhang, Renhe; Zhou, Ji-Xun (IEEE, 2004-10)Two field programs, both parts of the Asian Seas International Acoustics Experiment (ASIAEX), were carried out in the central East China Sea (28 to 30 N, 126 30 to 128 E) during April 2000 and June 2001. The goal of ...
Distributions of dissolved and particulate iron in the sub-Antarctic and Polar Frontal Southern Ocean (Australian sector) Lannuzel, Delphine; Bowie, Andrew R.; Remenyi, Tomas A.; Lam, Phoebe J.; Townsend, Ashley T.; Ibisanmi, Enitan; Butler, Edward; Wagener, Thibaut; Schoemann, Veronique (2011-01)This paper presents iron (Fe) profiles in the upper 1000 m from nine short-term (transect) stations and three long-term (process) stations occupied in the Australian sector of the Southern Ocean during the SAZ-Sense ...