Importance of mesoscale eddies and mean circulation in ventilation of the Southern Ocean

Igor Kamenkovich, Zulema Garraffo, Romain Pennel, Rana A Fine

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

This study examines the relative importance of the mean advection and mesoscale currents in the property exchange between the Southern Ocean mixed layer and downstream in the upper 2000 m; this exchange is referred to as ventilation. A new, highly efficient off-line tracer model employed here uses precalculated velocities to advect dynamically passive tracers. Two idealized tracers are considered: the Boundary Impulse Response (BIR) tracer, which helps to determine the ventilation pathways and time scales, and the Transient Surface Tracer (TST), which is relevant to transient atmospheric tracers. The importance of eddies is isolated by contrasting the control simulation with a simulation without mesoscale currents. The analysis reveals complex three-dimensional ventilation pathways, controlled by the interplay between the mean advection and eddy-induced spreading. The mean currents carry the tracers eastward within ACC and contribute to the formation of the Antarctic Intermediate Water (AAIW) in the South Pacific and South Atlantic. The main effect of eddies is to disperse tracers away from the mean pathways, and this dispersion acts to retain the BIR tracer in the Atlantic and Indian sectors and reduce the upstream influence of these regions on the South Pacific. In addition, the eddy-induced along-isopycnal spreading within ACC increases the ventilated depth and the inventory of TST. The results can be used to interpret distribution of tracers in the ocean in numerical simulations and observations.

Original languageEnglish (US)
Pages (from-to)2724-2741
Number of pages18
JournalJournal of Geophysical Research: Oceans
Volume122
Issue number4
DOIs
StatePublished - Apr 1 2017

Fingerprint

mesoscale eddy
ventilation
Ventilation
tracers
tracer techniques
oceans
tracer
Advection
vortices
Impulse response
ocean
eddy
Water
advection
Computer simulation
impulses
control simulation
simulation
Antarctic Intermediate Water
upstream

Keywords

  • mesoscale eddies
  • Southern Ocean
  • tracers
  • ventilation

ASJC Scopus subject areas

  • Geophysics
  • Oceanography
  • Forestry
  • Ecology
  • Aquatic Science
  • Water Science and Technology
  • Soil Science
  • Geochemistry and Petrology
  • Earth-Surface Processes
  • Atmospheric Science
  • Earth and Planetary Sciences (miscellaneous)
  • Space and Planetary Science
  • Palaeontology

Cite this

Importance of mesoscale eddies and mean circulation in ventilation of the Southern Ocean. / Kamenkovich, Igor; Garraffo, Zulema; Pennel, Romain; Fine, Rana A.

In: Journal of Geophysical Research: Oceans, Vol. 122, No. 4, 01.04.2017, p. 2724-2741.

Research output: Contribution to journalArticle

@article{db2ba5a6889745f085af1cc01e600f7d,
title = "Importance of mesoscale eddies and mean circulation in ventilation of the Southern Ocean",
abstract = "This study examines the relative importance of the mean advection and mesoscale currents in the property exchange between the Southern Ocean mixed layer and downstream in the upper 2000 m; this exchange is referred to as ventilation. A new, highly efficient off-line tracer model employed here uses precalculated velocities to advect dynamically passive tracers. Two idealized tracers are considered: the Boundary Impulse Response (BIR) tracer, which helps to determine the ventilation pathways and time scales, and the Transient Surface Tracer (TST), which is relevant to transient atmospheric tracers. The importance of eddies is isolated by contrasting the control simulation with a simulation without mesoscale currents. The analysis reveals complex three-dimensional ventilation pathways, controlled by the interplay between the mean advection and eddy-induced spreading. The mean currents carry the tracers eastward within ACC and contribute to the formation of the Antarctic Intermediate Water (AAIW) in the South Pacific and South Atlantic. The main effect of eddies is to disperse tracers away from the mean pathways, and this dispersion acts to retain the BIR tracer in the Atlantic and Indian sectors and reduce the upstream influence of these regions on the South Pacific. In addition, the eddy-induced along-isopycnal spreading within ACC increases the ventilated depth and the inventory of TST. The results can be used to interpret distribution of tracers in the ocean in numerical simulations and observations.",
keywords = "mesoscale eddies, Southern Ocean, tracers, ventilation",
author = "Igor Kamenkovich and Zulema Garraffo and Romain Pennel and Fine, {Rana A}",
year = "2017",
month = "4",
day = "1",
doi = "10.1002/2016JC012292",
language = "English (US)",
volume = "122",
pages = "2724--2741",
journal = "Journal of Geophysical Research: Oceans",
issn = "2169-9275",
publisher = "Wiley-Blackwell",
number = "4",

}

TY - JOUR

T1 - Importance of mesoscale eddies and mean circulation in ventilation of the Southern Ocean

AU - Kamenkovich, Igor

AU - Garraffo, Zulema

AU - Pennel, Romain

AU - Fine, Rana A

PY - 2017/4/1

Y1 - 2017/4/1

N2 - This study examines the relative importance of the mean advection and mesoscale currents in the property exchange between the Southern Ocean mixed layer and downstream in the upper 2000 m; this exchange is referred to as ventilation. A new, highly efficient off-line tracer model employed here uses precalculated velocities to advect dynamically passive tracers. Two idealized tracers are considered: the Boundary Impulse Response (BIR) tracer, which helps to determine the ventilation pathways and time scales, and the Transient Surface Tracer (TST), which is relevant to transient atmospheric tracers. The importance of eddies is isolated by contrasting the control simulation with a simulation without mesoscale currents. The analysis reveals complex three-dimensional ventilation pathways, controlled by the interplay between the mean advection and eddy-induced spreading. The mean currents carry the tracers eastward within ACC and contribute to the formation of the Antarctic Intermediate Water (AAIW) in the South Pacific and South Atlantic. The main effect of eddies is to disperse tracers away from the mean pathways, and this dispersion acts to retain the BIR tracer in the Atlantic and Indian sectors and reduce the upstream influence of these regions on the South Pacific. In addition, the eddy-induced along-isopycnal spreading within ACC increases the ventilated depth and the inventory of TST. The results can be used to interpret distribution of tracers in the ocean in numerical simulations and observations.

AB - This study examines the relative importance of the mean advection and mesoscale currents in the property exchange between the Southern Ocean mixed layer and downstream in the upper 2000 m; this exchange is referred to as ventilation. A new, highly efficient off-line tracer model employed here uses precalculated velocities to advect dynamically passive tracers. Two idealized tracers are considered: the Boundary Impulse Response (BIR) tracer, which helps to determine the ventilation pathways and time scales, and the Transient Surface Tracer (TST), which is relevant to transient atmospheric tracers. The importance of eddies is isolated by contrasting the control simulation with a simulation without mesoscale currents. The analysis reveals complex three-dimensional ventilation pathways, controlled by the interplay between the mean advection and eddy-induced spreading. The mean currents carry the tracers eastward within ACC and contribute to the formation of the Antarctic Intermediate Water (AAIW) in the South Pacific and South Atlantic. The main effect of eddies is to disperse tracers away from the mean pathways, and this dispersion acts to retain the BIR tracer in the Atlantic and Indian sectors and reduce the upstream influence of these regions on the South Pacific. In addition, the eddy-induced along-isopycnal spreading within ACC increases the ventilated depth and the inventory of TST. The results can be used to interpret distribution of tracers in the ocean in numerical simulations and observations.

KW - mesoscale eddies

KW - Southern Ocean

KW - tracers

KW - ventilation

UR - http://www.scopus.com/inward/record.url?scp=85017335472&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85017335472&partnerID=8YFLogxK

U2 - 10.1002/2016JC012292

DO - 10.1002/2016JC012292

M3 - Article

VL - 122

SP - 2724

EP - 2741

JO - Journal of Geophysical Research: Oceans

JF - Journal of Geophysical Research: Oceans

SN - 2169-9275

IS - 4

ER -