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Direct measurements of dissipation rate of turbulent kinetic energy of North Pacific subtropical mode water
Author(s) -
Mori Kosuke,
Uehara Kazuyuki,
Kameda Takahiko,
Kakehi Shigeho
Publication year - 2008
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 - 10.1029/2007gl032867
Subject(s) - mode water , potential vorticity , turbulence kinetic energy , kinetic energy , magnitude (astronomy) , vorticity , dissipation , energy budget , subtropics , geostrophic wind , eddy diffusion , turbulence , atmospheric sciences , environmental science , climatology , physics , geology , meteorology , vortex , thermodynamics , biology , classical mechanics , astronomy , ocean gyre , fishery
Measurements of turbulent kinetic energy dissipation rate ɛ were performed in a region of North Pacific subtropical mode water (STMW), and the vertical eddy diffusivity K z was calculated from the observed ɛ values. In summer, the magnitude of ɛ in the STMW interior was 2–3 × 10 −10 Wkg −1 , whereas the values at both the upper and lower boundaries of STMW were 4–6 × 10 −10 Wkg −1 . In winter, on the other hand, ɛ was almost uniform and had a magnitude less than 10 −10 Wkg −1 over the whole depth of STMW. The magnitude of K z was mostly from 10 −6 to 10 −5 m 2 s −1 in summer and from 10 −7 to 10 −5 m 2 s −1 in winter. These are at least one order of magnitude smaller than the inferred value from a budget analysis of potential vorticity in STMW.