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Spin-down of a baroclinic vortex by irregular small-scale topography

Published online by Cambridge University Press:  02 December 2022

Timour Radko*
Affiliation:
Department of Oceanography, Naval Postgraduate School, Monterey, CA 93943, USA
*
Email address for correspondence: [email protected]

Abstract

This study explores the impact of small-scale variability in the bottom relief on the dynamics and evolution of broad baroclinic flows in the ocean. The analytical model presented here generalizes the previously reported barotropic ‘sandpaper’ theory of flow–topography interaction to density-stratified systems. The multiscale asymptotic analysis leads to an explicit representation of the large-scale effects of irregular bottom roughness. The utility of the multiscale model is demonstrated by applying it to the problem of topography-induced spin-down of an axisymmetric vortex. We find that bathymetry affects vortices by suppressing circulation in their deep regions. As a result, vortices located above rough topography tend to be more stable than their flat-bottom counterparts. The multiscale theory is validated by comparing corresponding topography-resolving and parametric simulations.

Type
JFM Papers
Copyright
© The Author(s), 2022. Published by Cambridge University Press

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References

REFERENCES

Arbic, B., Fringer, O., Klymak, J., Mayer, F., Trossman, D. & Zhu, P. 2019 Connecting process models of topographic wave drag to global eddying general circulation models. Oceanography 32, 146155.CrossRefGoogle Scholar
Arbic, B.K. & Flierl, G.R. 2004 Baroclinically unstable geostrophic turbulence in the limits of strong and weak bottom Ekman friction: application to midocean eddies. J. Phys. Oceanogr. 34, 22572273.2.0.CO;2>CrossRefGoogle Scholar
Benilov, E.S. 2000 The stability of zonal jets in a rough-bottomed ocean on the barotropic beta plane. J. Phys. Oceanogr. 30, 733740.2.0.CO;2>CrossRefGoogle Scholar
Benilov, E.S. 2001 Baroclinic instability of two-layer flows over one-dimensional bottom topography. J. Phys. Oceanogr. 31, 20192025.2.0.CO;2>CrossRefGoogle Scholar
Bleck, R. 2002 An oceanic general circulation model framed in hybrid isopycnic–Cartesian coordinates. Ocean Model. 4, 5558.CrossRefGoogle Scholar
Brown, J., Gulliver, L. & Radko, T. 2019 Effects of topography and orientation on the nonlinear equilibration of baroclinic instability. J. Geophys. Res. Oceans 124, 67206734.CrossRefGoogle Scholar
Chelton, D.B., Schlax, M.G. & Samelson, R.M. 2011 Global observations of nonlinear mesoscale eddies. Prog. Oceanogr. 91, 167216.CrossRefGoogle Scholar
Chen, C., Kamenkovich, I. & Berloff, P. 2015 On the dynamics of flows induced by topographic ridges. J. Phys. Oceanogr. 45, 927940.CrossRefGoogle Scholar
Dewar, W.K. 1998 Topography and barotropic transport control by bottom friction. J. Mar. Res. 56, 295328.CrossRefGoogle Scholar
Dewar, W.K., Berloff, P. & Hogg, A.M. 2011 Submesoscale generation by boundaries. J. Mar. Res. 69, 501522.CrossRefGoogle Scholar
Dewar, W.K. & Hogg, A.M. 2010 Topographic inviscid dissipation of balanced flow. Ocean Model. 32, 113.CrossRefGoogle Scholar
Dewar, W.K. & Killworth, P.D. 1995 On the stability of oceanic rings. J. Phys. Oceanogr. 25, 14671487.2.0.CO;2>CrossRefGoogle Scholar
Dewar, W.K. & Killworth, P.D. 1999 Primitive-equation instability of wide oceanic rings. Part II: numerical studies of ring stability. J. Phys. Oceanogr. 29, 17441758.2.0.CO;2>CrossRefGoogle Scholar
Dritschel, D.G. 1988 Nonlinear stability bounds for inviscid, two-dimensional, parallel or circular flows with montonic vorticity, and the analogous 3-dimensional quasi-geostrophic flows. J. Fluid Mech. 191, 575581.CrossRefGoogle Scholar
Eden, C., Olbers, D. & Eriksen, T. 2021 A closure for lee wave drag on the large-scale ocean circulation. J. Phys. Oceanogr. 51, 35733588.Google Scholar
Gama, S., Vergassola, M. & Frisch, U. 1994 Negative eddy viscosity in isotropically forced 2-dimensional flow – linear and nonlinear dynamics. J. Fluid Mech. 260, 95126.CrossRefGoogle Scholar
Goff, J.A. 2020 Identifying characteristic and anomalous mantle from the complex relationship between abyssal hill roughness and spreading rates. Geophys. Res. Lett. 47, e2020GL088162.CrossRefGoogle Scholar
Goff, J.A. & Jordan, T.H. 1988 Stochastic modeling of seafloor morphology: inversion of sea beam data for second-order statistics. J. Geophys. Res. 93, 13,58913,608.CrossRefGoogle Scholar
Goldsmith, E.J. & Esler, J.G. 2021 Wave propagation in rotating shallow water in the presence of small-scale topography. J. Fluid Mech. 923, A24.CrossRefGoogle Scholar
Gulliver, L. & Radko, T. 2022 Topographic Stabilization of Ocean Rings. Geophys. Res. Lett. 49, e2021GL097686.CrossRefGoogle Scholar
von Helmholtz, H. 1888 Über atmosphärische Bewegungen. Sitzungsberichte der Koeniglich Preussischen Akad. Wiss. Berlin 3, 647663.Google Scholar
Holloway, G. 1987 Systematic forcing of large-scale geophysical flows by eddy-topography interaction. J. Fluid Mech. 184, 463476.CrossRefGoogle Scholar
Holloway, G. 1992 Representing topographic stress for large-scale ocean models. J. Phys. Oceanogr. 22, 10331046.2.0.CO;2>CrossRefGoogle Scholar
Hughes, C.W. & De Cuevas, B.A. 2001 Why western boundary currents in realistic oceans are inviscid: a link between form stress and bottom pressure torques. J. Phys. Oceanogr. 31, 28712885.2.0.CO;2>CrossRefGoogle Scholar
Jackson, L., Hughes, C.W. & Williams, R.G. 2006 Topographic control of basin and channel flows: the role of bottom pressure torques and friction. J. Phys. Oceanogr. 36, 17861805.CrossRefGoogle Scholar
Klymak, J.M., Balwada, D., Garabato, A.N. & Abernathey, R. 2021 Parameterizing nonpropagating form drag over rough bathymetry. J. Phys. Oceanogr. 51, 14891501.CrossRefGoogle Scholar
LaCasce, J., Escartin, J., Chassignet, E.P. & Xu, X. 2019 Jet instability over smooth, corrugated, and realistic bathymetry. J. Phys. Oceanogr. 49, 585605.CrossRefGoogle Scholar
Li, Q.Y., Sun, L. & Xu, C. 2018 The lateral eddy viscosity derived from the decay of oceanic mesoscale eddies. Open J. Mar. Sci. 8, 152172.CrossRefGoogle Scholar
Margules, M. 1906 Uber Temperaturschichtung in stationar bewegter und ruhender Luft. Meteorol. Z. 23, 243254.Google Scholar
Marshall, D. 1995 Topographic steering of the Antarctic Circumpolar Current. J. Phys. Oceanogr/. 25, 16361650.2.0.CO;2>CrossRefGoogle Scholar
McWilliams, J.C. 1974 Forced transient flow and small scale topography. Geophys. Astrophys. Fluid Dyn. 6, 4979.CrossRefGoogle Scholar
Mei, C.C. & Vernescu, M. 2010 Homogenization Methods for Multiscale Mechanics. World Scientific Publishing.CrossRefGoogle Scholar
Munk, W.H. & Palmén, E. 1951 Note on the dynamics of the Antarctic Circumpolar Current 1. Tellus 3, 5355.CrossRefGoogle Scholar
Naveira Garabato, A.C., Nurser, A.G., Scott, R.B. & Goff, J.A. 2013 The impact of small-scale topography on the dynamical balance of the ocean. J. Phys. Oceanogr. 43, 647668.CrossRefGoogle Scholar
Nikurashin, M., Ferrari, R., Grisouard, N. & Polzin, K. 2014 The impact of finite-amplitude bottom topography on internal wave generation in the Southern Ocean. J. Phys. Oceanogr. 44, 29382950.CrossRefGoogle Scholar
Novikov, A. & Papanicolau, G. 2001 Eddy viscosity of cellular flows. J. Fluid Mech. 446, 173198.CrossRefGoogle Scholar
Olbers, D., Borowski, D., Völker, C. & Wolff, J.-O. 2004 The dynamical balance, transport and circulation of the Antarctic Circumpolar Current. Antarct. Sci. 16, 439470.CrossRefGoogle Scholar
Olson, D.B. 1991 Rings in the ocean. Annu. Rev. Earth Planet. Sci. 19, 283311.CrossRefGoogle Scholar
Pedlosky, J. 1987 Geophysical Fluid Dynamics. Springer.CrossRefGoogle Scholar
Phillips, N.A. 1951 A simple three-dimensional model for the study of large scale extra tropical flow pattern. J. Met. 8, 381394.2.0.CO;2>CrossRefGoogle Scholar
Radko, T. 2020 Control of baroclinic instability by submesoscale topography. J. Fluid Mech. 882, A14.CrossRefGoogle Scholar
Radko, T. 2022 Spin-down of a barotropic vortex by irregular small-scale topography. J. Fluid Mech. 944, A5.CrossRefGoogle Scholar
Radko, T. & Kamenkovich, I. 2017 On the topographic modulation of large-scale eddying flows. J. Phys. Oceanogr. 47, 21572172.CrossRefGoogle Scholar
Radko, T., McWilliams, J.C. & Sutyrin, G.G. 2022 Equilibration of baroclinic instability in westward flows. J. Phys. Oceanogr. 52, 2138.CrossRefGoogle Scholar
Sengupta, D., Piterbarg, L.I. & Reznik, G.M. 1992 Localization of topographic Rossby waves over random relief. Dyn. Atmos. Oceans 17, 121.CrossRefGoogle Scholar
Stewart, A.L., McWilliams, J.C. & Solodoch, A. 2021 On the role of bottom pressure torques in wind-driven gyres. J. Phys. Oceanogr. 51, 14411464.CrossRefGoogle Scholar
Thierry, V. & Morel, Y. 1999 Influence of a strong bottom slope on the evolution of a surface-intensified vortex. J. Phys. Oceanogr. 29, 911924.2.0.CO;2>CrossRefGoogle Scholar
Tréguier, A.M. & McWilliams, J.C. 1990 Topographic influences on wind-driven, stratified flow in a β-plane channel: an idealized model for the Antarctic Circumpolar Current. J. Phys. Oceanogr. 20, 321343.2.0.CO;2>CrossRefGoogle Scholar
Vanneste, J. 2000 Enhanced dissipation for quasi-geostrophic motion over small-scale topography. J. Fluid Mech. 407, 105122.CrossRefGoogle Scholar
Vanneste, J. 2003 Nonlinear dynamics over rough topography: homogeneous and stratified quasi-geostrophic theory. J. Fluid Mech. 474, 299318.CrossRefGoogle Scholar
Wåhlin, A.K. 2002 Topographic steering of dense currents with application to submarine canyons. Deep-Sea Res. Part I: Oceanogr. Res. Papers 49, 305320.CrossRefGoogle Scholar