Pairwise surface drifter separation in the western Pacific sector of the Southern Ocean

The Southern Ocean plays a critical role in global climate, yet the mixing properties of the circulation in this part of the ocean remain poorly understood. Here dispersion in the vicinity of the Southern Antarctic Circumpolar Current Front, one of the branches of the Antarctic Circumpolar Current,...

Full description

Saved in:
Bibliographic Details
Published in:Journal of geophysical research. Oceans 2015-10, Vol.120 (10), p.6769-6781
Main Authors: van Sebille, Erik, Waterman, Stephanie, Barthel, Alice, Lumpkin, Rick, Keating, Shane R., Fogwill, Chris, Turney, Chris
Format: Article
Language:English
Subjects:
Antarctic Circumpolar Current
Antarctic front
Antarctica
Australasian Antarctic Expedition (AAE)
Diffusion coefficients
Diffusivity
Dispersion
Dispersions
Drift
Drifters
drifting buoys
eddy diffusivity
Flanks
Geophysics
Global climate
Liapunov exponents
Marine
Ocean circulation
Ocean currents
Oceanography
Oceans
Separation
Southern Ocean
Surface drifters
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The Southern Ocean plays a critical role in global climate, yet the mixing properties of the circulation in this part of the ocean remain poorly understood. Here dispersion in the vicinity of the Southern Antarctic Circumpolar Current Front, one of the branches of the Antarctic Circumpolar Current, is studied using 10 pairs of surface drifters deployed systematically across the frontal jet and its flanks. Drifter pairs were deployed with an initial separation of 13 m and report their position every hour. The separation of the pairs over 7 months, in terms of their Finite‐Scale Lyapunov Exponents (FSLE), dispersion, and diffusivity, is characterized and related to expected behavior from Quasi‐Geostrophic (QG) and Surface Quasi‐Geostrophic (SQG) theories. The FSLE analysis reveals two submesoscale regimes, with SQG‐like behavior at scales below 3.2 km and mixed QG/SQG behavior at scales between 3.2 and 73 km. The dispersion analysis, however, suggests QG‐like behavior for the smallest scales. Both dispersion and diffusivity appear isotropic for scales up to 500 km. Finally, there is no clear indication of a cross‐jet variation of drifter dispersion. Key Points: Surface drifters are deployed in pairs south of New Zealand Dispersion between pairs is used to study mixing in the Southern Ocean Dispersion characteristics have generally lower magnitude than in North Atlantic
ISSN:2169-9275
2169-9291
DOI:10.1002/2015JC010972