• Chang, E. K. M., 2006: An idealized nonlinear model of the Northern Hemisphere winter storm tracks. J. Atmos. Sci., 63 , 18181839.

  • Frierson, D. M. W., , I. M. Held, , and P. Zurita-Gotor, 2006: A gray-radiation aquaplanet moist GCM. Part I: Static stability and eddy scale. J. Atmos. Sci., 63 , 25482566.

    • Search Google Scholar
    • Export Citation
  • Frierson, D. M. W., , I. M. Held, , and P. Zurita-Gotor, 2007: A gray-radiation aquaplanet moist GCM. Part II: Energy transports in altered climates. J. Atmos. Sci., 64 , 16801693.

    • Search Google Scholar
    • Export Citation
  • Held, I. M., 2007: Progress and problems in large-scale atmospheric dynamics. The Global Circulation of the Atmosphere, T. Schneider and A. H. Sobel, Eds., Princeton University Press, 1–21.

    • Search Google Scholar
    • Export Citation
  • Held, I. M., , and V. Larichev, 1996: A scaling theory for horizontally homogeneous, baroclinically unstable flow on a beta plane. J. Atmos. Sci., 53 , 946952.

    • Search Google Scholar
    • Export Citation
  • Lapeyre, G., , and I. M. Held, 2003: Diffusivity, kinetic energy dissipation, and closure theories for the poleward eddy heat flux. J. Atmos. Sci., 60 , 29072916.

    • Search Google Scholar
    • Export Citation
  • Salmon, R., 1980: Baroclinic instability and geostrophic turbulence. Geophys. Astrophys. Fluid Dyn., 15 , 167211.

  • Schneider, T., 2004: The tropopause and thermal stratification in the extratropics of a dry atmosphere. J. Atmos. Sci., 61 , 13171340.

    • Search Google Scholar
    • Export Citation
  • Schneider, T., , and P. O’Gorman, 2008: Moist convection and the thermal stratification of the extratropical troposphere. J. Atmos. Sci., 65 , 35713583.

    • Search Google Scholar
    • Export Citation
  • Stone, P. H., 1978: Baroclinic adjustment. J. Atmos. Sci., 35 , 561571.

  • Stone, P. H., , and L. Branscome, 1992: Diabatically forced, nearly inviscid eddy regimes. J. Atmos. Sci., 49 , 355367.

  • Vallis, G. K., 1988: Numerical studies of eddy transport properties in eddy-resolving and parametrized models. Quart. J. Roy. Meteor. Soc., 114 , 183204.

    • Search Google Scholar
    • Export Citation
  • Welch, W., , and K-K. Tung, 1998: Nonlinear baroclinic adjustment and wavenumber selection in a simple case. J. Atmos. Sci., 55 , 12851302.

    • Search Google Scholar
    • Export Citation
  • Zurita-Gotor, P., 2007: The relation between baroclinic adjustment and turbulent diffusion in the two-layer model. J. Atmos. Sci., 64 , 12841300.

    • Search Google Scholar
    • Export Citation
  • Zurita-Gotor, P., 2008: The sensitivity of the isentropic slope in a primitive equation dry model. J. Atmos. Sci., 65 , 4365.

  • Zurita-Gotor, P., , and R. S. Lindzen, 2006: A generalized momentum framework for looking at baroclinic circulations. J. Atmos. Sci., 63 , 20362055.

    • Search Google Scholar
    • Export Citation
  • Zurita-Gotor, P., , and R. S. Lindzen, 2007: Theories of baroclinic adjustment and eddy equilibration. The Global Circulation of the Atmosphere, T. Schneider and A. H. Sobel, Eds., Princeton University Press, 22–46.

    • Search Google Scholar
    • Export Citation
  • Zurita-Gotor, P., , and G. K. Vallis, 2009: Equilibration of baroclinic turbulence in primitive equations and quasigeostrophic models. J. Atmos. Sci., 66 , 837863.

    • Search Google Scholar
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 11 11 1
PDF Downloads 4 4 2

Circulation Sensitivity to Heating in a Simple Model of Baroclinic Turbulence

View More View Less
  • 1 Universidad Complutense, and Instituto de Geociencia, Madrid, Spain
  • | 2 GFDL, Princeton University, Princeton, New Jersey
© Get Permissions
Restricted access

Abstract

This paper examines the sensitivity of the circulation of an idealized primitive equation two-level model on the form and strength of the heating, aiming to understand the qualitatively different sensitivity of the isentropic slope on differential heating reported by previous idealized studies when different model formulations are used. It is argued that this contrasting behavior might arise from differences in the internal determination of the heating. To test this contention, the two-level model is forced using two different heating formulations: a standard Newtonian cooling formulation and a highly simplified formulation in which the net lower-to-upper troposphere heat transport is prescribed by construction. The results are interpreted using quasigeostrophic turbulent closures, which have previously been shown to have predictive power for the model. It is found that the strength of the circulation, as measured by eddy length and velocity scales and by the strength of the energy cycle, scales with the vertical heating (the lower-to-upper troposphere heat transport), with a weak dependence. By contrast, the isentropic slope is only sensitive to the structure of the heating, as measured by the ratio between meridional versus vertical heating, and not to the actual strength of the heating. In general the heating is internally determined, and this ratio may either increase or decrease as the circulation strengthens. It is shown that the sign of the sensitivity depends on the steepness of the relation between vertical heating and stratification for the particular heating formulation used. The quasigeostrophic limit (fixed stratification) and the prescribed heating model constrain the possible range of behaviors and provide bounds of sensitivity for the model. These results may help explain the different sensitivity of the isentropic slope on differential heating for dry and moist models and for quasigeostrophic and primitive equation models.

Corresponding author address: Pablo Zurita-Gotor, Departamento de Geofísica y Meteorología, Universidad Complutense, Facultad de Ciencias Físicas, Madrid 28040, Spain. Email: pzurita@alum.mit.edu

Abstract

This paper examines the sensitivity of the circulation of an idealized primitive equation two-level model on the form and strength of the heating, aiming to understand the qualitatively different sensitivity of the isentropic slope on differential heating reported by previous idealized studies when different model formulations are used. It is argued that this contrasting behavior might arise from differences in the internal determination of the heating. To test this contention, the two-level model is forced using two different heating formulations: a standard Newtonian cooling formulation and a highly simplified formulation in which the net lower-to-upper troposphere heat transport is prescribed by construction. The results are interpreted using quasigeostrophic turbulent closures, which have previously been shown to have predictive power for the model. It is found that the strength of the circulation, as measured by eddy length and velocity scales and by the strength of the energy cycle, scales with the vertical heating (the lower-to-upper troposphere heat transport), with a weak dependence. By contrast, the isentropic slope is only sensitive to the structure of the heating, as measured by the ratio between meridional versus vertical heating, and not to the actual strength of the heating. In general the heating is internally determined, and this ratio may either increase or decrease as the circulation strengthens. It is shown that the sign of the sensitivity depends on the steepness of the relation between vertical heating and stratification for the particular heating formulation used. The quasigeostrophic limit (fixed stratification) and the prescribed heating model constrain the possible range of behaviors and provide bounds of sensitivity for the model. These results may help explain the different sensitivity of the isentropic slope on differential heating for dry and moist models and for quasigeostrophic and primitive equation models.

Corresponding author address: Pablo Zurita-Gotor, Departamento de Geofísica y Meteorología, Universidad Complutense, Facultad de Ciencias Físicas, Madrid 28040, Spain. Email: pzurita@alum.mit.edu

Save