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Eddy surface properties and propagation at Southern Hemisphere western boundary current systems

Citation

Pilo, GS and Mata, MM and Azevedo, JLL, Eddy surface properties and propagation at Southern Hemisphere western boundary current systems, Ocean Science, 11, (4) pp. 629-641. ISSN 1812-0784 (2015) [Refereed Article]


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Copyright Statement

Author(s) 2015. Licensed under Creative Commons Attribution 3.0 Unported (CC BY 3.0) http://creativecommons.org/licenses/by/3.0/

DOI: doi:10.5194/os-11-629-2015

Abstract

Oceanic eddies exist throughout the world oceans, but are more energetic when associated with western boundary currents (WBC) systems. In these regions, eddies play an important role in mixing and energy exchange. Therefore, it is important to quantify and qualify eddies associated with these systems. This is particularly true for the Southern Hemisphere WBC system where only few eddy censuses have been performed to date. In these systems, important aspects of the local eddy population are still unknown, like their spatial distribution and propagation patterns. Moreover, the understanding of these patterns helps to establish monitoring programs and to gain insight in how eddies would affect local mixing. Here, we use a global eddy data set to qualify eddies based on their surface characteristics in the Agulhas Current (AC), the Brazil Current (BC) and the East Australian Current (EAC) systems. The analyses reveal that eddy propagation within each system is highly forced by the local mean flow and bathymetry. Large values of eddy amplitude and temporal variability are associated with the BC and EAC retroflections, while small values occur in the centre of the Argentine Basin and in the Tasman Sea. In the AC system, eddy polarity dictates the propagation distance. BC system eddies do not propagate beyond the Argentine Basin, and are advected by the local ocean circulation. EAC system eddies from both polarities cross south of Tasmania but only the anticyclonic ones reach the Great Australian Bight. For all three WBC systems, both cyclonic and anticyclonic eddies present a geographical segregation according to radius size and amplitude. Regions of high eddy kinetic energy are associated with the eddies' mean amplitudes, and not with their densities.

Item Details

Item Type:Refereed Article
Keywords:oceanic eddies, Western Boundary Currents, Southern Hemisphere WBC
Research Division:Earth Sciences
Research Group:Oceanography
Research Field:Physical Oceanography
Objective Division:Environment
Objective Group:Physical and Chemical Conditions of Water
Objective Field:Physical and Chemical Conditions of Water in Marine Environments
Author:Pilo, GS (Ms Gabriela Pilo)
ID Code:106672
Year Published:2015
Web of Science® Times Cited:3
Deposited By:IMAS Research and Education Centre
Deposited On:2016-02-17
Last Modified:2016-05-19
Downloads:53 View Download Statistics

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