Seasonal meandering of the polar front upstream of the Kerguelen Plateau

• Published in: Geophysical Research Letters
• Main Authors: Pauthenet, E, Roquet, F, Madec, G, Guinet, C, Hindell, M, McMahon, CR, Harcourt, R, Nerini, D
• Format: Article in Journal/Newspaper
• Language: English
• Published: Amer Geophysical Union 2018
• Subjects: Southern Ocean; ecosystems; tracking; Antarctic Polar Front; Kerguelen Plateau; Southern Indian Ocean; Southern Ocean fronts; functional principal component analysis; Antarctic; The Antarctic; Kerguelen; Kerguelen Islands; Indian; Conrad Rise; Antarc*
• Online Access: https://eprints.utas.edu.au/43377/; https://eprints.utas.edu.au/43377/1/130087%20-%20Seasonal%20meandering%20of%20the%20polar%20front%20upstream%20of%20the%20Kerguelen%20Plateau.pdf

The location of the Antarctic Polar Front (PF) is mapped in the Southern Indian Ocean by decomposing the shape of temperature and salinity profiles into vertical modes using a functional Principal Component Analysis. We define the PF as the northernmost minimum of temperature at the subsurface and represent it as a linear combination of the first three modes. This method is applied on an ocean reanalysis data set and on in situ observations, revealing a seasonal variability of the PF latitudinal position that is most pronounced between the Conrad Rise and the Kerguelen Plateau. This shift coincides with variations in the transport across the Northern Kerguelen Plateau. We suggest that seasonal changes of the upper stratification may drive the observed variability of the PF, with potentially large implications for the pathways and residence time of water masses over the plateau and the phytoplankton bloom extending southeast of the Kerguelen Islands.