On low-frequency variability of the midlatitude ocean gyres
File(s)
Accepted version
Author(s)
Shevchenko, I
Berloff, P
Guerrero-López, D
Roman, J
Type
Journal Article
Abstract
This paper studies the large-scale low-frequency variability of the wind-driven midlatitude ocean gyres and their western boundary currents, such as the Gulf Stream or Kuroshio, simulated with the eddy-resolving quasi-geostrophic model. We applied empirical orthogonal functions analysis to turbulent flow solutions and statistically extracted robust and significant large-scale decadal variability modes concentrated around the eastward jet extension of the western boundary currents. In order to interpret these statistical modes dynamically, we linearized the governing quasi-geostrophic equations around the time-mean circulation and solved for the corresponding full set of linear eigenmodes with their eigenfrequencies. We then projected the extracted decadal variability on the eigenmodes and found that this variability is a multimodal coherent pattern phenomenon rather than a single mode or a combination of several modes as in the flow regimes preceding developed turbulence.
Date Issued
2016-04-15
Date Acceptance
2016-03-15
Citation
Journal of Fluid Mechanics, 2016, 795, pp.423-442
ISSN
1469-7645
Publisher
Cambridge University Press (CUP)
Start Page
423
End Page
442
Journal / Book Title
Journal of Fluid Mechanics
Volume
795
Copyright Statement
The final publication is available via Cambridge Journals Online at http://dx.doi.org/10.1017/jfm.2016.208
Sponsor
Natural Environment Research Council (NERC)
Grant Number
NE/J006602/1
Subjects
Fluids & Plasmas
01 Mathematical Sciences
09 Engineering
Publication Status
Published