The Loop Current: Observations of deep eddies and topographic waves.

View/ Open
Date
2019-05-29Author
Hamilton, Peter
Concept link
Bower, Amy S.
Concept link
Furey, Heather H.
Concept link
Leben, Robert
Concept link
Pérez-Brunius, Paula
Concept link
Metadata
Show full item recordCitable URI
https://hdl.handle.net/1912/24326As published
https://doi.org/10.1175/JPO-D-18-0213.1DOI
10.1175/JPO-D-18-0213.1Keyword
Bottom currents; Eddies; Instability; Lagrangian circulation/transport; Mesoscale processes; Topographic effectsAbstract
A set of float trajectories, deployed at 1500- and 2500-m depths throughout the deep Gulf of Mexico from 2011 to 2015, are analyzed for mesoscale processes under the Loop Current (LC). In the eastern basin, December 2012–June 2014 had >40 floats per month, which was of sufficient density to allow capturing detailed flow patterns of deep eddies and topographic Rossby waves (TRWs), while two LC eddies formed and separated. A northward advance of the LC front compresses the lower water column and generates an anticyclone. For an extended LC, baroclinic instability eddies (of both signs) develop under the southward-propagating large-scale meanders of the upper-layer jet, resulting in a transfer of eddy kinetic energy (EKE) to the lower layer. The increase in lower-layer EKE occurs only over a few months during meander activity and LC eddy detachment events, a relatively short interval compared with the LC intrusion cycle. Deep EKE of these eddies is dispersed to the west and northwest through radiating TRWs, of which examples were found to the west of the LC. Because of this radiation of EKE, the lower layer of the eastern basin becomes relatively quiescent, particularly in the northeastern basin, when the LC is retracted and a LC eddy has departed. A mean west-to-east, anticyclone–cyclone dipole flow under a mean LC was directly comparable to similar results from a previous moored LC array and also showed connections to an anticlockwise boundary current in the southeastern basin.
Description
Author Posting. © American Meteorological Society, 2019. 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 49(6), (2019):1463-1483, doi: 10.1175/JPO-D-18-0213.1.
Collections
Suggested Citation
WHOI Hamilton, P., Bower, A., Furey, H., Leben, R., & Perez-Brunius, P. (2019). The Loop Current: Observations of deep eddies and topographic waves. Journal of Physical Oceanography, 49(6), 1463-1483.Related items
Showing items related by title, author, creator and subject.
-
Some dynamical constraints on upstream pathways of the Denmark Strait Overflow
Yang, Jiayan; Pratt, Lawrence J. (American Meteorological Society, 2014-12)The East Greenland Current (EGC) had long been considered the main pathway for the Denmark Strait overflow (DSO). Recent observations, however, indicate that the north Icelandic jet (NIJ), which flows westward along the ... -
An asymmetric upwind flow, Yellow Sea Warm Current : 2. Arrested topographic waves in response to the northwesterly wind
Lin, Xiaopei; Yang, Jiayan (American Geophysical Union, 2011-04-29)A warm and salty water mass exists along the Yellow Sea Trough (YST) in winter. This oceanic water mass is distinct from the ambient shelf water and is distributed on the western side of the YST. It has long been reasoned ... -
Shelf circulation and cross-shelf transport out of a bay driven by eddies from an open-ocean current. Part I : interaction between a barotropic vortex and a steplike topography
Zhang, Yu; Pedlosky, Joseph; Flierl, Glenn R. (American Meteorological Society, 2011-05)This paper examines interaction between a barotropic point vortex and a steplike topography with a bay-shaped shelf. The interaction is governed by two mechanisms: propagation of topographic Rossby waves and advection by ...