eCite Digital Repository

Subantarctic mode water in the southeast Pacific: effect of exchange across the Subantarctic Front

Citation

Holte, JW and Talley, LD and Chereskin, TK and Sloyan, BM, Subantarctic mode water in the southeast Pacific: effect of exchange across the Subantarctic Front, Journal of Geophysical Research: Oceans, 118, (4) pp. 2052-2066. ISSN 2169-9291 (2013) [Refereed Article]


Preview
PDF
2Mb
  

Copyright Statement

Copyright 2013 American Geophysical Union

DOI: doi:10.1002/jgrc.20144

Abstract

This study considered cross-frontal exchange as a possible mechanism for the observed along-front freshening and cooling between the 27.0 and 27.3 kg m − 3 isopycnals north of the Subantarctic Front (SAF) in the southeast Pacific Ocean. This isopycnal range, which includes the densest Subantarctic Mode Water (SAMW) formed in this region, is mostly below the mixed layer, and so experiences little direct air-sea forcing. Data from two cruises in the southeast Pacific were examined for evidence of cross-frontal exchange; numerous eddies and intrusions containing Polar Frontal Zone (PFZ) water were observed north of the SAF, as well as a fresh surface layer during the summer cruise that was likely due to Ekman transport. These features penetrated north of the SAF, even though the potential vorticity structure of the SAF should have acted as a barrier to exchange. An optimum multiparameter (OMP) analysis incorporating a range of observed properties was used to estimate the cumulative cross-frontal exchange. The OMP analysis revealed an along-front increase in PFZ water fractional content in the region north of the SAF between the 27.1 and 27.3 kg m − 3 isopycnals; the increase was approximately 0.13 for every 15 of longitude. Between the 27.0 and 27.1 kg m − 3 isopycnals, the increase was approximately 0.15 for every 15 of longitude. A simple bulk calculation revealed that this magnitude of cross-frontal exchange could have caused the downstream evolution of SAMW temperature and salinity properties observed by Argo profiling floats.

Item Details

Item Type:Refereed Article
Keywords:Southern Ocean, Subantarctic mode water
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
Author:Sloyan, BM (Dr Bernadette Sloyan)
ID Code:119542
Year Published:2013
Web of Science® Times Cited:7
Deposited By:CRC-Antarctic Climate & Ecosystems
Deposited On:2017-08-02
Last Modified:2017-09-20
Downloads:1 View Download Statistics

Repository Staff Only: item control page