Please use this identifier to cite or link to this item: http://hdl.handle.net/10553/238
Title: On the relevance of diapycnal mixing for the stability of frontal meanders
Authors: Rodríguez Santana, Ángel 
Pelegrí Llopart, José Luis 
Sangrà, Pablo 
Marrero Díaz, Ángeles 
UNESCO Clasification: 2204 Física de fluidos
251007 Oceanografía física
Keywords: Diapycnal mixing
Barotropic instability
Meanders
Oceanic jets
Atmospheric jets
Issue Date: 2001
Journal: Scientia Marina 
Conference: Workshop and Conference on Oceanography
Abstract: This work examines the possible importance of shear-induced diapycnal mixing in controlling the evolutionand stability of meanders in oceanic frontal jets. We first review the conditions necessary for vortex stability and investi-gate how these may be modified in the presence of diapycnal mixing. The procedure used is rather crude but provides a mea-sure of the relative importance of diapycnal mixing. It consists in constructing a simplified equation for the radial velocitythat retains the density tendency and examining under what circumstances this velocity may grow in time. Next, we use asimple two-dimensional isopycnic model to examine the intensity of diapycnal mixing in meanders. In the model the along-front velocity is in geostrophic balance and the ageostrophic contributions are an oscillating deformation field and diapyc-nal mass exchange. The horizontal deformation field increases the slope of the isopycnals in temporal scales typical of GulfStream meanders, causing a reduction of the gradient Richardson number, Ri. The diapycnal flux is calculated as the diver-gence of the density Reynolds flux, which is parameterized in terms of Ri.The results of the model show that diapycnal mix-ing increases during the frontogenetical stages, reaching density tendency values of the order of 10-4kg m-3s-1and conver-gence/divergence values of the order of 10-3s-1. It turns out that diapycnal mixing in meanders may be intense enough to control the separation and slope of the isopycnals and to condition the possibility of barotropic instability.
URI: http://hdl.handle.net/10553/238
ISSN: 0214-8358
DOI: 10.3989/scimar.2001.65s1259
Source: Scientia Marina [ISSN 0214-8358], v. 65 (supl. 1), p. 259-267
Appears in Collections:Artículos
Thumbnail
PDF
Adobe PDF (833,9 kB)
Show full item record

SCOPUSTM   
Citations

4
checked on Jul 25, 2021

WEB OF SCIENCETM
Citations

5
checked on Jul 25, 2021

Page view(s)

89
checked on Jun 23, 2021

Download(s)

89
checked on Jun 23, 2021

Google ScholarTM

Check

Altmetric


Share



Export metadata



Items in accedaCRIS are protected by copyright, with all rights reserved, unless otherwise indicated.