• Böning, C. W., and R. G. Budich, 1992: Eddy dynamics in a primitive equation model: Sensitivity to horizontal resolution and friction. J. Phys. Oceanogr, 22 , 361381.

    • Search Google Scholar
    • Export Citation
  • Cessi, P., 1991: Laminar separation of colliding western boundary currents. J. Mar. Res, 49 , 697717.

  • Cessi, P., and G. R. Ierley, 1995: Symmetry-breaking multiple equilibria in quasigeostrophic, wind-driven flows. J. Phys. Oceanogr, 25 , 11961205.

    • Search Google Scholar
    • Export Citation
  • Chang, K-I., M. Ghil, K. Ide, and C-C. A. Lai, 2001: Transition to aperiodic variability in a wind-driven double-gyre circulation model. J. Phys. Oceanogr, 31 , 12601286.

    • Search Google Scholar
    • Export Citation
  • Chassignet, E., and P. Gent, 1991: The influence of boundary conditions on midlatitude jet separation in ocean models. J. Phys. Oceanogr, 21 , 12901299.

    • Search Google Scholar
    • Export Citation
  • Chassignet, E., and Z. D. Garraffo, 2001: Viscosity parameterization and the Gulf Stream separation. From Stirring to Mixing in a Stratified Ocean: Proc. 'Aha Huliko'a Hawaiian Winter Workshop, Honolulu, HI, University of Hawaii at Manoa, 37–41.

    • Search Google Scholar
    • Export Citation
  • Dijkstra, H. A., 2000: Nonlinear Physical Oceanography. Kluwer Academic, 480 pp.

  • Dijkstra, H. A., and C. A. Katsman, 1997: Temporal variability of the wind-driven quasi-geostrophic double gyre ocean circulation: Basic bifurcation diagrams. Geophys. Astrophys. Fluid Dyn, 85 , 195232.

    • Search Google Scholar
    • Export Citation
  • Dijkstra, H. A., and M. J. Molemaker, 1999: Imperfections of the North-Atlantic wind-driven ocean circulation: Continental geometry and wind stress shape. J. Mar. Res, 57 , 128.

    • Search Google Scholar
    • Export Citation
  • Doedel, E. J., 1981: AUTO: A program for the automatic bifurcation analysis of autonomous systems. Proc. 10th Manitoba Conf. on Numerical Mathematics and Computing, Winnipeg, MB, Canada, University of Manitoba, 265–284.

    • Search Google Scholar
    • Export Citation
  • Gent, P. R., 1993: The energetically consistent shallow-water equations. J. Atmos. Sci, 50 , 13231325.

  • Holland, W. R., and L. B. Lin, 1975: On the generation of mesoscale eddies and their contribution to the ocean general circulation. I. A preliminary numerical experiment. J. Phys. Oceanogr, 5 , 642657.

    • Search Google Scholar
    • Export Citation
  • Hurlburt, H. E., and P. J. Hogan, 2000: Impact of 1/8° to 1/64° resolution on Gulf Stream model–data comparisons in basin-scale subtropical Atlantic Ocean models. Dyn. Atmos. Oceans, 32 , 283329.

    • Search Google Scholar
    • Export Citation
  • Jiang, S., F-F. Jin, and M. Ghil, 1995: Multiple equilibria and aperiodic solutions in a wind-driven double gyre, shallow water model. J. Phys. Oceanogr, 25 , 764786.

    • Search Google Scholar
    • Export Citation
  • McWilliams, J. C., 1996: Modeling the ocean general circulation. Annu. Rev. Fluid Mech, 28 , 215248.

  • Munk, W., 1950: On the wind-driven ocean circulation. J. Meteor, 7 , 7993.

  • Nadiga, B. T., and B. P. Luce, 2001: Global bifurcation of Shilnikov type in a double-gyre ocean model. J. Phys. Oceanogr, 31 , 26692690.

    • Search Google Scholar
    • Export Citation
  • Nauw, J. J., and H. A. Dijkstra, 2001: The origin of low-frequency variability of double-gyre wind-driven flows. J. Mar. Res, 59 , 567597.

    • Search Google Scholar
    • Export Citation
  • Pedlosky, J., 1987: Geophysical Fluid Dynamics. 2d ed. Springer-Verlag, 710 pp.

  • Pedlosky, J., 1996: Ocean Circulation Theory. Springer, 453 pp.

  • Schmeits, M. J., and H. A. Dijkstra, 2000: Physics of the 9-month variability in the Gulf Stream region: Combining data and dynamical systems analyses. J. Phys. Oceanogr, 30 , 19671987.

    • Search Google Scholar
    • Export Citation
  • Schmeits, M. J., and H. A. Dijkstra, 2001: Bimodal behavior of the Kuroshio and the Gulf Stream. J. Phys. Oceanogr, 31 , 34353456.

  • Simonnet, E., and H. A. Dijkstra, 2002: Spontaneous generation of low-frequency modes of variability in the wind-driven ocean circulation. J. Phys. Oceanogr, 32 , 17471762.

    • Search Google Scholar
    • Export Citation
  • Smith, R. D., M. E. Maltrud, F. O. Bryan, and M. W. Hecht, 2000: Numerical simulation of the North Atlantic Ocean at 1/10°. J. Phys. Oceanogr, 30 , 15321561.

    • Search Google Scholar
    • Export Citation
  • Speich, S., H. A. Dijkstra, and M. Ghil, 1995: Successive bifurcations in a shallow-water model applied to the wind-driven ocean circulation. Nonlinear Processes Geophys, 2 , 241268.

    • Search Google Scholar
    • Export Citation
  • Stommel, H., 1948: The westward intensification of wind-driven ocean currents. Trans. Amer. Geophys. Union, 29 , 202206.

  • Sverdrup, H. U., 1947: Wind-driven currents in a baroclinic ocean with application to the equatorial current in the eastern Pacific. Proc. Natl. Acad. Sci, 33 , 318326.

    • Search Google Scholar
    • Export Citation
  • Van der Vaart, P. C. F., H. M. Schuttelaars, D. Calvete, and H. A. Dijkstra, 2002: Instability of time-dependent wind-driven ocean gyres. Phys. Fluids, 14 , 36013615.

    • Search Google Scholar
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 150 15 3
PDF Downloads 9 6 0

Frictionally Induced Asymmetries in Wind-Driven Flows

View More View Less
  • 1 Institute for Marine and Atmospheric Research Utrecht, Department of Physics and Astronomy, Utrecht University, Utrecht, Netherlands
  • | 2 Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, Florida
Restricted access

Abstract

The effect of the parameterization of lateral friction on the separation of western boundary currents is addressed in an idealized context. The study is motivated by a puzzling issue that arises from the nonlinear theory of the wind-driven double-gyre circulation in shallow-water models. Subtle changes in the representation of the lateral friction in these models have a substantial effect on both steady-state and transient flows. The aim of this paper is to explain how lateral friction introduces a north–south asymmetry in the steady double-gyre flows and why the degree of this asymmetry depends on the type of frictional parameterization. A more conceptual model of a zonal jet in a channel turns out to be very useful to determine the dynamical processes behind the asymmetries. It is also shown that the north–south asymmetries have an impact on the low-frequency variability of the time-dependent flows. This is caused by changes in stability behavior of the steady-state flows.

Current affiliation: Department of Atmospheric Science, Colorado State University, Fort Collins, Colorado

Corresponding author address: Dr. Janine J. Nauw, Institute for Marine and Atmospheric Research Utrecht, Department of Physics and Astronomy, Utrecht University, Princetonplein 5, 3584 CC Utrecht, Netherlands. Email: j.j.nauw@phys.uu.nl

Abstract

The effect of the parameterization of lateral friction on the separation of western boundary currents is addressed in an idealized context. The study is motivated by a puzzling issue that arises from the nonlinear theory of the wind-driven double-gyre circulation in shallow-water models. Subtle changes in the representation of the lateral friction in these models have a substantial effect on both steady-state and transient flows. The aim of this paper is to explain how lateral friction introduces a north–south asymmetry in the steady double-gyre flows and why the degree of this asymmetry depends on the type of frictional parameterization. A more conceptual model of a zonal jet in a channel turns out to be very useful to determine the dynamical processes behind the asymmetries. It is also shown that the north–south asymmetries have an impact on the low-frequency variability of the time-dependent flows. This is caused by changes in stability behavior of the steady-state flows.

Current affiliation: Department of Atmospheric Science, Colorado State University, Fort Collins, Colorado

Corresponding author address: Dr. Janine J. Nauw, Institute for Marine and Atmospheric Research Utrecht, Department of Physics and Astronomy, Utrecht University, Princetonplein 5, 3584 CC Utrecht, Netherlands. Email: j.j.nauw@phys.uu.nl

Save