Description of the Perturbations of Oceanic Geostrophic Currents with Linear Vertical Velocity Shear Taking into Account Friction and Diffusion of Density
- Authors: Kuzmina N.P.1, Skorokhodov S.L.2, Zhurbas N.V.1, Lyzhkov D.A.1
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Affiliations:
- Shirshov Institute of Oceanology, Russian Academy of Sciences
- Federal Research Center Computer Science and Control, Russian Academy of Sciences
- Issue: Vol 55, No 2 (2019)
- Pages: 207-217
- Section: Article
- URL: https://journals.rcsi.science/0001-4338/article/view/148707
- DOI: https://doi.org/10.1134/S0001433819020117
- ID: 148707
Cite item
Abstract
Abstract—A spectral problem of the Orr–Sommerfeld type for describing stable and unstable perturbations of oceanic geostrophic flows with linear vertical velocity shear is considered (parabolic vertical velocity profile). Calculations of eigenvalues, increments of growth rate of unstable modes, and eigenfunctions of the fastest growing perturbations are presented. It is found that the instability of the geostrophic flow is observed over a wide range of horizontal scales: in addition to longwave perturbations with a phase velocity exceeding the maximum velocity of the geostrophic current and perturbations with the scales of the Rossby radius, shortwave modes exist with scales much smaller than the Rossby radius (submesoscale structures). The results of the model are used to describe intrusions in the Arctic basin, which are observed under conditions of absolutely stable stratification.
About the authors
N. P. Kuzmina
Shirshov Institute of Oceanology, Russian Academy of Sciences
Author for correspondence.
Email: kuzmina@ocean.ru
Russian Federation, Moscow, 117997
S. L. Skorokhodov
Federal Research Center Computer Science and Control, Russian Academy of Sciences
Author for correspondence.
Email: sskorokhodov@gmail.com
Russian Federation, Moscow, 119333
N. V. Zhurbas
Shirshov Institute of Oceanology, Russian Academy of Sciences
Email: sskorokhodov@gmail.com
Russian Federation, Moscow, 117997
D. A. Lyzhkov
Shirshov Institute of Oceanology, Russian Academy of Sciences
Email: sskorokhodov@gmail.com
Russian Federation, Moscow, 117997