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Vertical mixing due to double diffusion in the tropical western Pacific
Author(s) -
Lee Chorong,
Chang KyungIl,
Lee Jae Hak,
Richards Kelvin J.
Publication year - 2014
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 - 10.1002/2014gl061698
Subject(s) - turbulence , buoyancy , thermal diffusivity , turbulence kinetic energy , turbulent diffusion , diffusion , flux (metallurgy) , eddy diffusion , mixing (physics) , magnitude (astronomy) , mechanics , dissipation , k epsilon turbulence model , atmospheric sciences , physics , thermodynamics , materials science , quantum mechanics , astronomy , metallurgy
This study calculates the vertical diffusivity and the fluxes of heat, salt, and buoyancy due to turbulence and double diffusion based on a 14 day time series of observations of the dissipation rates of turbulent kinetic energy and thermal variance at 0°N, 156°E from 25 October to 18 November 2012. Salt fingering dominates shear‐driven turbulence below 100 m. The estimated flux and associated vertical diffusivity due to double diffusion are approximately 1 order of magnitude higher for temperature and density and 2 orders of magnitude higher for salinity compared to values calculated from a turbulence model. Under weak turbulence conditions, the turbulence model significantly underestimates the magnitude of the vertical buoyancy flux with the flux having the wrong sign. Under these conditions, fluxes induced by double‐diffusive mixing need to be considered.