Pathways of the Agulhas waters poleward of 29 degrees S

TitlePathways of the Agulhas waters poleward of 29 degrees S
Publication TypeJournal Article
Year of Publication2014
AuthorsWang J.B, Mazloff MR, Gille ST
JournalJournal of Geophysical Research-Oceans
Volume119
Pagination4234-4250
Date Published2014/07
Type of ArticleArticle
ISBN Number2169-9275
Accession NumberWOS:000340415500012
Keywordscirculation; climate; Fronts; inter-ocean exchange; leakage; mode; southern-ocean; transport; undercurrent; variability
Abstract

Passive tracers are advected in a Southern Ocean State Estimate (SOSE) to map the pathways of Agulhas waters, with a focus on determining where the Agulhas waters intrude into the Antarctic Circumpolar Current (ACC). Results show that Agulhas waters spread into all three ocean basins within 3 years of release. After leaving the African continent, the mean Agulhas water pathway tilts northwest toward the South Atlantic and southeast toward the ACC. The majority (from 60% to 100% depending on specific water mass) of the Agulhas waters stay in the South Indian Ocean north of the Sub-Antarctic Front. From 10 to 28% enters the South Atlantic Ocean through the boundary current along the southern tip of South Africa and via Agulhas rings in the retroflection region. Up to 12% of intermediate depth Agulhas waters enter the ACC. Most of the tracer transport into the ACC occurs just downstream of the Kerguelen Plateau, which clearly demonstrates the importance of topography in elevating cross-frontal exchange. Agulhas waters also contribute to Sub-Antarctic Mode Water formation in the Southeast Indian Ocean by lateral advection. The surface Agulhas waters are preconditioned by strong surface buoyancy loss before turning into mode water, while the intermediate Agulhas waters are advected to the mode water formation region along isopycnals before being drawn into the mixed layer.

DOI10.1002/2014jc010049
Short TitleJ Geophys Res-Oceans
Integrated Research Themes: 
Student Publication: 
No