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Observations of the structure of turbulent mixing across the Kuroshio
Author(s) -
Kaneko Hitoshi,
Yasuda Ichiro,
Komatsu Kosei,
Itoh Sachihiko
Publication year - 2012
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2012gl052419
Subject(s) - geology , geostrophic wind , anticyclone , turbulence , front (military) , turbulence kinetic energy , shear (geology) , atmospheric sciences , climatology , meteorology , physics , oceanography , petrology
The mean structure of turbulence intensity across the Kuroshio in spring is presented by compositing microstructure profiles on a stream coordinate. The composite mean of turbulent energy dissipation rate ε ¯ was high near fronts on both cyclonic and anticyclonic sides. On the cyclonic side, ε ¯ > 10 −8 W kg −1 (vertical diffusivity of > 3 × 10 −5 m 2 s −1 ) was observed in the region of strong vertical shear of geostrophic velocity. Depth‐averaged ε ¯ within the depth range 50–150 m (150–250 m) was significantly higher at 0 to 50 km (−25 to 50 km) compared with >50 km from the axis. Although lower than on the cyclonic side, ε ¯ at depths of 50–150 m on the anticyclonic side near the front was again enhanced. On this side, the total vertical shear of horizontal velocity was strong, whereas the geostrophic shear was weak.