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Strong vertical mixing in the Urup Strait
Author(s) -
Itoh Sachihiko,
Yasuda Ichiro,
Yagi Masahiro,
Osafune Satoshi,
Kaneko Hitoshi,
Nishioka Jun,
Nakatsuka Takeshi,
Volkov Yuri N.
Publication year - 2011
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 - 10.1029/2011gl048507
Subject(s) - sill , geology , ocean gyre , mixing (physics) , water column , oceanography , homogeneous , turbulence , internal tide , dissipation , thermal diffusivity , atmospheric sciences , subtropics , internal wave , petrology , meteorology , physics , quantum mechanics , fishery , biology , thermodynamics
Microstructure measurements were conducted in one of the Kuril Straits in the summer of 2007. Over the course of 1 day of repeated observations across the Pacific side of the steep sill of the Urup Strait, extremely strong mixing was observed during periods of Pacific‐ward (down‐sill) flows and during the transition from Pacific‐ward to Okhotsk‐ward (up‐sill) flows, with a turbulent energy dissipation rate ɛ of 10 −6 to 10 −5 W kg −1 and vertical diffusivity of 10 −1 to 5 × 10 −1 m 2 s −1 . During the period of strong mixing, we observed homogeneous layers with a thickness of 300–600 m and potential density of 26.6–26.7 σ θ , occupying the entire water column in one case. High values of ɛ within this layer indicate the injection of diapycnal flows from the upper and lower layers, possibly contributing to southward intrusion of intermediate water into the subtropical gyre.