Formation of Jets by Baroclinic Instability on Gas Planet Atmospheres

Yohai Kaspi Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts

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Glenn R. Flierl Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts

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Abstract

In this paper it is proposed that baroclinic instability of even a weak shear may play an important role in the generation and stability of the strong zonal jets observed in the atmospheres of the giant planets. The atmosphere is modeled as a two-layer structure, where the upper layer is a standard quasigeostrophic layer on a β plane and the lower layer is parameterized to represent a deep interior convective columnar structure using a negative β plane as in Ingersoll and Pollard. Linear stability theory predicts that the high wavenumber perturbations will be the dominant unstable modes for a small vertical wind shear like that inferred from observations. Here a nonlinear analytical model is developed that is truncated to one growing mode that exhibits a multiple jet meridional structure, driven by the nonlinear interaction between the eddies. In the weakly supercritical limit, this model agrees with previous weakly nonlinear theory, but it can be explored beyond this limit allowing the multiple jet–induced zonal flow to be stronger than the eddy field. Calculations with a fully nonlinear pseudospectral model produce stable meridional multijet structures when beginning from a random potential vorticity perturbation field. The instability removes energy from the background weak baroclinic shear and generates turbulent eddies that undergo an inverse energy cascade and form multijet zonal winds. The jets are the dominant feature in the instantaneous upper-layer flow, with the eddies being relatively weak. The jets scale with the Rhines length, but are strong enough to violate the barotropic stability criterion. It is shown that the basic physical mechanism for the generation and stability of the jets in the full numerical model is similar to that of the truncated model.

Corresponding author address: Yohai Kaspi, Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Rm. 54-1417, Cambridge, MA 02139. Email: yohai@mit.edu

This article included in the Jets and Annular Structures in Geophysical Fluids (Jets) special collection.

Abstract

In this paper it is proposed that baroclinic instability of even a weak shear may play an important role in the generation and stability of the strong zonal jets observed in the atmospheres of the giant planets. The atmosphere is modeled as a two-layer structure, where the upper layer is a standard quasigeostrophic layer on a β plane and the lower layer is parameterized to represent a deep interior convective columnar structure using a negative β plane as in Ingersoll and Pollard. Linear stability theory predicts that the high wavenumber perturbations will be the dominant unstable modes for a small vertical wind shear like that inferred from observations. Here a nonlinear analytical model is developed that is truncated to one growing mode that exhibits a multiple jet meridional structure, driven by the nonlinear interaction between the eddies. In the weakly supercritical limit, this model agrees with previous weakly nonlinear theory, but it can be explored beyond this limit allowing the multiple jet–induced zonal flow to be stronger than the eddy field. Calculations with a fully nonlinear pseudospectral model produce stable meridional multijet structures when beginning from a random potential vorticity perturbation field. The instability removes energy from the background weak baroclinic shear and generates turbulent eddies that undergo an inverse energy cascade and form multijet zonal winds. The jets are the dominant feature in the instantaneous upper-layer flow, with the eddies being relatively weak. The jets scale with the Rhines length, but are strong enough to violate the barotropic stability criterion. It is shown that the basic physical mechanism for the generation and stability of the jets in the full numerical model is similar to that of the truncated model.

Corresponding author address: Yohai Kaspi, Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Rm. 54-1417, Cambridge, MA 02139. Email: yohai@mit.edu

This article included in the Jets and Annular Structures in Geophysical Fluids (Jets) special collection.

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  • Atkinson, D. H., J. B. Pollack, and A. Seiff, 1996: Galileo Doppler measurements of the deep zonal winds at Jupiter. Science, 272 , 842843.

    • Search Google Scholar
    • Export Citation
  • Aurnou, J. M., and P. L. Olson, 2001: Strong zonal winds from thermal convection in a rotating spherical shell. Geophys. Res. Lett., 28 , 25572559.

    • Search Google Scholar
    • Export Citation
  • Boyd, J. P., 2001: Chebyshev and Fourier Spectral Methods. 2d ed. Dover, 668 pp.

  • Busse, F. H., 1970: Thermal instabilities in rapidly rotating systems. J. Fluid Mech., 44 , 441460.

  • Busse, F. H., 1976: A simple model of convection in the Jovian atmosphere. Icarus, 29 , 255260.

  • Busse, F. H., 1994: Convection driven zonal flows and vortices in the major planets. Chaos, 4 , 2. 123134.

  • Cho, J., and L. M. Polvani, 1996: The formation of jets and vortices from freely-evolving shallow water turbulence on the surface of a sphere. Phys. Fluids, 8 , 15311552.

    • Search Google Scholar
    • Export Citation
  • Christensen, U. R., 2002: Zonal flow driven by strongly supercritical convection in rotating spherical shells. J. Fluid Mech., 470 , 115133.

    • Search Google Scholar
    • Export Citation
  • Conrath, B. J., F. M. Flasar, J. A. Pirraglia, P. J. Gierasch, and G. E. Hunt, 1981: Thermal structure and dynamics of the Jovian atmosphere. II—Visible cloud features. J. Geophys. Res., 86 , 87698775.

    • Search Google Scholar
    • Export Citation
  • Dowling, T. E., and A. P. Ingersoll, 1989: Jupiter’s Great Red Spot as a shallow water system. J. Atmos. Sci., 46 , 32563278.

  • Flierl, G. R., 1992: Deep jets and shallow spots. Geophysical Fluid Dynamics summer study program. Woods Hole Oceanographic Institution Tech. Rep. WHOI-93-24, 432 pp.

  • Galperin, B., S. Sukoriansky, and H-P. Huang, 2001: Universal n-5 spectrum of zonal flows on giant planets. Phys. Fluids, 13 , 15451548.

    • Search Google Scholar
    • Export Citation
  • Galperin, B., S. Sukoriansky, P. Read, Y. Yamazaki, and R. Wordsworth, 2006: Anisotropic turbulence and zonal jets in rotating flows with a beta effect. Nonlinear Proc. Geophys., 13 , 8398.

    • Search Google Scholar
    • Export Citation
  • Gierasch, P. J., J. A. Magalhaes, and B. J. Conrath, 1986: Zonal mean properties of Jupiter’s upper troposphere from Voyager infrared observations. Icarus, 67 , 456483.

    • Search Google Scholar
    • Export Citation
  • Guillot, T., 1999: Interiors of giant planets inside and outside the solar system. Science, 286 , 7277.

  • Hanel, R. A., B. J. Conrath, L. Herath, V. Kunde, and J. Pirraglia, 1981: Albedo, internal heat, and energy balance of Jupiter—Preliminary results of the Voyager infrared investigation. J. Geophys. Res., 86 , 87058712.

    • Search Google Scholar
    • Export Citation
  • Hanel, R. A., B. J. Conrath, V. G. Kunde, J. C. Pearl, and J. A. Pirraglia, 1983: Albedo, internal heat flux, and energy balance of Saturn. Icarus, 53 , 262285.

    • Search Google Scholar
    • Export Citation
  • Heimpel, M., J. Aurnou, and J. Wicht, 2005: Simulation of equatorial and high-latitude jets on Jupiter in a deep convection model. Nature, 438 , 193196.

    • Search Google Scholar
    • Export Citation
  • Huang, H-P., and W. A. Robinson, 1998: Two-dimensional turbulence and persistent zonal jets in a global barotropic model. J. Atmos. Sci., 55 , 611632.

    • Search Google Scholar
    • Export Citation
  • Huang, H-P., B. Galperin, and S. Sukoriansky, 2001: Generation of mean flows and jets on a beta plane and over topography. Phys. Fluids, 13 , 225240.

    • Search Google Scholar
    • Export Citation
  • Ingersoll, A. P., 1976: Pioneer 10 and 11 observations and the dynamics of Jupiter’s atmosphere. Icarus, 29 , 245252.

  • Ingersoll, A. P., 1990: Atmospheric dynamics of the outer planets. Science, 248 , , 308315.

  • Ingersoll, A. P., and D. Pollard, 1982: Motion in the interiors and atmospheres of Jupiter and Saturn: Scale analysis, anelastic equations, barotropic stability criterion. Icarus, 52 , 6280.

    • Search Google Scholar
    • Export Citation
  • Ingersoll, A. P., R. F. Beebe, J. L. Mitchell, G. W. Garneau, G. M. Yagi, and J-P. Muller, 1981: Interaction of eddies and mean zonal flow on Jupiter as inferred from Voyager 1 and 2 images. J. Geophys. Res., 86 , 87338743.

    • Search Google Scholar
    • Export Citation
  • Kuo, H. L., 1949: Dynamic instability of two-dimensional nondivergent flow in a barotropic atmosphere. J. Meteor., 6 , 105122.

  • Lee, S., 2005: Baroclinic multiple zonal jets on a sphere. J. Atmos. Sci., 62 , 24842498.

  • Manifori, A. J., and W. R. Young, 1999: Slow evolution of zonal jets on the beta plane. J. Atmos. Sci., 56 , 784800.

  • Manneville, J. B., and P. Olson, 1996: Banded convection in rotating fluid spheres and the circulation of the Jovian atmosphere. Icarus, 122 , 242250.

    • Search Google Scholar
    • Export Citation
  • Panetta, R. L., 1993: Zonal jets in wide baroclinically unstable regions: Persistence and scale selection. J. Atmos. Sci., 50 , 20732106.

    • Search Google Scholar
    • Export Citation
  • Pearl, J. C., and B. J. Conrath, 1991: The albedo, effective temperature, and energy balance of Neptune, as determined from Voyager data. J. Geophys. Res., 96 , 1892118930.

    • Search Google Scholar
    • Export Citation
  • Pedlosky, J., 1970: Finite-amplitude baroclinic waves. J. Atmos. Sci., 27 , 1530.

  • Pedlosky, J., 1987: Geophysical Fluid Dynamics. Springer-Verlag, 710 pp.

  • Phillips, N. A., 1954: Energy transformations and meridional circulations associated with simple baroclinic waves in a two level quasi-geostrophic model. Tellus, 6 , 273286.

    • Search Google Scholar
    • Export Citation
  • Porco, C. C., and Coauthors, 2003: Cassini imaging of Jupiter’s atmosphere, satellites and rings. Science, 299 , 15411547.

  • Porco, C. C., and Coauthors, 2005: Cassini imaging science: Initial results on Saturn’s atmosphere. Science, 307 , 12431247.

  • Rhines, P. B., 1975: Waves and turbulence on a beta plane. J. Fluid Mech., 69 , 417443.

  • Rhines, P. B., 1979: Geostrophic turbulence. Annu. Rev. Fluid Mech., 11 , 401441.

  • Robinson, A. R., and J. McWilliams, 1974: The baroclinic instability of the open ocean. J. Phys. Oceanogr., 4 , 281294.

  • Seiff, A., and Coauthors, 1996: Structure of the atmosphere of Jupiter: Galileo probe measurements. Science, 272 , 844845.

  • Smith, B. A., and Coauthors, 1982: A new look at the Saturn system: The Voyager 2 images. Science, 215 , 505537.

  • Smith, K. S., 2004: A local model for planetary atmospheres forced by small-scale convection. J. Atmos. Sci., 61 , 14201433.

  • Stamp, A. P., and T. E. Dowling, 1993: Jupiter’s winds and Arnol’d’s second stability theorem: Slowly moving waves and neutral stability. J. Geophys. Res., 98 , 1884718855.

    • Search Google Scholar
    • Export Citation
  • Steinsaltz, D., 1987: Instability of baroclinic waves with bottom slope. J. Phys. Oceanogr., 17 , 23432350.

  • Sun, Z-P., G. Schubert, and G. A. Glatzmaier, 1993: Banded surface flow maintained by convection in a model of the rapidly rotating giant planets. Science, 260 , 661664.

    • Search Google Scholar
    • Export Citation
  • Vallis, G. K., and M. E. Maltrud, 1993: Generation of mean flows and jets on a beta plane and over topography. J. Phys. Oceanogr., 23 , 13461362.

    • Search Google Scholar
    • Export Citation
  • Williams, G. P., 1978: Planetary circulations: 1. Barotropic representation of Jovian and terrestrial turbulence. J. Atmos. Sci., 35 , 13991426.

    • Search Google Scholar
    • Export Citation
  • Williams, G. P., 1979: Planetary circulations: 2. The Jovian quasi-geostrophic regime. J. Atmos. Sci., 36 , 932969.

  • Williams, G. P., 2003: Jovian dynamics. Part III: Multiple, migrating, and equatorial jets. J. Atmos. Sci., 60 , 12701296.

  • Yano, J. I., 2005: Origins of atmospheric zonal winds. Nature, 421 , 36.

  • Yano, J. I., and G. R. Flierl, 1994: Jupiter’s Great Red Spot: Compactness condition and stability. Ann. Geophys., 12 , 118.

  • Zhang, K., and G. Schubert, 1996: Penetrative convection and zonal flow on Jupiter. Science, 273 , 941943.

  • Zhang, K., and G. Schubert, 1997: Linear penetrative spherical rotating convection. J. Atmos. Sci., 54 , 25092518.

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