Effects of turbulent mixing and horizontal shear on double-diffusive interleaving in the central and western equatorial Pacific SCIE SCOPUS

Cited 6 time in WEB OF SCIENCE Cited 5 time in Scopus
Title
Effects of turbulent mixing and horizontal shear on double-diffusive interleaving in the central and western equatorial Pacific
Author(s)
Kuzmina, N; Lee, JH; Zhurbas, V
KIOST Author(s)
Lee, Jae Hak(이재학)
Publication Year
2004-01
Abstract
The effects of small-scale turbulence and the horizontal shear on double-diffusive interleaving are treated in the framework of a linear stability problem in the equatorial beta-plane approximation. The model predicts the decrease of the vertical wavenumber (m(max)) and growth rate (lambda(max)) for the fastest-growing intrusion with the increase in the turbulent diffusivity and predicts increased lambda(max) and decreased m(max) with the horizontal shear of the mean zonal flow. The effects of turbulent mixing are analyzed at different values of the Prandtl number, and the criteria of instability are obtained analytically for some simple cases. Special attention is focused on the influence of the horizontal shear on instability, as with the f-plane models of interleaving. The CTD profiling data obtained from Korean and Russian research vessels are used to prove the model. A closely spaced CTD section across the equator at 176degrees16'W shows several intrusive layers with high lateral coherence throughout the section, which are suddenly broken inside a narrow latitudinal band. The model suggests that the breakdown results from enhanced turbulent mixing in the wake behind Baker Island, which is situated just 10 n mi west of the section. The CTD data collected in the section across the equator at 152degrees30'E reveal an intensification of intrusions in a latitudinal band where the Equatorial Undercurrent is found. In accordance with the model, the intensification supposedly results from the effect of the horizontal shear attributed to the undercurrent. In terms of the applications of the model results, the value of the turbulent mixing ratio is estimated in the wake behind Baker Island, and mechanisms of intrusive layering are discussed. It is found that the intrusions observed in a meridional section, from 2degrees to 1degreesS at 176degrees16'W, correspond satisfactorily to the 2D baroclinic instability triggered by double diffusion.
ISSN
0022-3670
URI
https://sciwatch.kiost.ac.kr/handle/2020.kiost/5314
DOI
10.1175/1520-0485(2004)034<0122:EOTMAH>2.0.CO;2
Bibliographic Citation
JOURNAL OF PHYSICAL OCEANOGRAPHY, v.34, no.1, pp.122 - 141, 2004
Publisher
AMER METEOROLOGICAL SOC
Subject
FINE-STRUCTURE; STABILITY; UNDERCURRENT; VARIABILITY; INSTABILITY; INTRUSIONS; OCEAN
Type
Article
Language
English
Document Type
Article
Publisher
AMER METEOROLOGICAL SOC
Related Researcher
Files in This Item:
There are no files associated with this item.

qrcode

Items in ScienceWatch@KIOST are protected by copyright, with all rights reserved, unless otherwise indicated.

Browse