eCite Digital Repository

Tracing Southwest Pacific Bottom Water using potential vorticity and helium-3

Citation

Downes, SM and Key, RM and Orsi, AH and Speer, KG and Swift, JH, Tracing Southwest Pacific Bottom Water using potential vorticity and helium-3, Journal of Physical Oceanography, 42, (12) pp. 2153-2168. ISSN 0022-3670 (2012) [Refereed Article]

Copyright Statement

© Copyright 2012 American Meteorological Society (AMS). Permission to use figures, tables, and brief excerpts from this work in scientific and educational works is hereby granted provided that the source is acknowledged. Any use of material in this work that is determined to be “fair use” under Section 107 of the U.S. Copyright Act September 2010 Page 2 or that satisfies the conditions specified in Section 108 of the U.S. Copyright Act (17 USC §108, as revised by P.L. 94-553) does not require the AMS’s permission. Republication, systematic reproduction, posting in electronic form, such as on a web site or in a searchable database, or other uses of this material, except as exempted by the above statement, requires written permission or a license from the AMS. Additional details are provided in the AMS Copyright Policy, available on the AMS Web site located at (http://www.ametsoc.org/) or from the AMS at 617-227-2425 or copyrights@ametsoc.org.

DOI: doi:10.1175/JPO-D-12-019.1

Abstract

This study uses potential vorticity and other tracers to identify the pathways of the densest form of Circumpolar Deep Water in the South Pacific, termed "Southwest Pacific Bottom Water" (SPBW), along the 28.2 kg m−3 surface. This study focuses on the potential vorticity signals associated with three major dynamical processes occurring in the vicinity of the Pacific–Antarctic Ridge: 1) the strong flow of the Antarctic Circumpolar Current (ACC), 2) lateral eddy stirring, and 3) heat and stratification changes in bottom waters induced by hydrothermal vents. These processes result in southward and downstream advection of low potential vorticity along rising isopycnal surfaces. Using δ3He released from the hydrothermal vents, the influence of volcanic activity on the SPBW may be traced across the South Pacific along the path of the ACC to Drake Passage. SPBW also flows within the southern limb of the Ross Gyre, reaching the Antarctic Slope in places and contributes via entrainment to the formation of Antarctic Bottom Water. Finally, it is shown that the magnitude and location of the potential vorticity signals associated with SPBW have endured over at least the last two decades, and that they are unique to the South Pacific sector.

Item Details

Item Type:Refereed Article
Keywords:Pacific Antarctic Ridge, hydrothermal plumes
Research Division:Earth Sciences
Research Group:Oceanography
Research Field:Physical Oceanography
Objective Division:Environment
Objective Group:Other Environment
Objective Field:Antarctic and Sub-Antarctic Oceanography
UTAS Author:Downes, SM (Dr Stephanie Downes)
ID Code:103127
Year Published:2012
Web of Science® Times Cited:2
Deposited By:CRC-Antarctic Climate & Ecosystems
Deposited On:2015-09-22
Last Modified:2017-11-06
Downloads:0

Repository Staff Only: item control page