The Equilibration of Short Baroclinic Waves

Balasubramanian Govindasamy Program in Atmospheric and Oceanic Sciences, Princeton University, Princeton, New Jersey

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S. T. Garner Geophysical Fluid Dynamics Laboratory/NOAA, Princeton, New Jersey

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Abstract

The life cycles of short baroclinic waves are investigated with the intention of completing a simple classification of nonlinear equilibration scenarios. Short waves become important in moist environments as latent heating reduces the scale of maximum baroclinic instability. Long-wave life cycles (wavenumber 6) were previously found to depend on details of the low-level momentum fluxes established during the earliest stages of development. These fluxes also serve as a focal point for the present study.

For a realistic, zonally symmetric jet on the sphere, the normal-mode life cycle of a short wave (wavenumber 8) under both dry and moist conditions is described. Latent heating intensifies the low pressure system and frontal zones but does not alter the broader details of the life cycle. The normal modes have predominantly equatorward momentum fluxes, in contrast to the mainly poleward momentum fluxes of long waves. The short waves are more meridionally confined. The equatorward momentum fluxes direct the waves toward cyclonic breaking. The feedback with the zonal-mean wind, the so-called barotropic governor, is less effective than in the standard long-wave life cycle, which ends in anticyclonic breaking. However, in contrast to long-wave life cycles that are “engineered” to produce equatorward momentum fluxes, relatively little potential vorticity and surface temperature anomaly roll up into isolated vortices. Therefore, the short wave undergoes protracted barotropic decay leading to complete zonalization. Short waves also have a brief period of baroclinic decay due to cold advection over the surface cyclones.

Eliassen–Palm cross sections for the short-wave life cycles show the usual combination of upward and meridional propagation of wave activity. However, the meridional propagation is mainly toward the pole and there is a consequent zonal-mean deceleration at high latitudes. These details are included in the proposed classification of equilibration scenarios.

* Current affiliation: Climate and Integrated System Modeling, Lawrence Livermore National Laboratory, Livermore, California.

Corresponding author address: Dr. Balasubramanian Govindasamy, Climate and Integrated System Modeling, Lawrence Livermore National Laboratory, P.O. Box 808, L-256, Livermore, CA 94551- 9900.

Abstract

The life cycles of short baroclinic waves are investigated with the intention of completing a simple classification of nonlinear equilibration scenarios. Short waves become important in moist environments as latent heating reduces the scale of maximum baroclinic instability. Long-wave life cycles (wavenumber 6) were previously found to depend on details of the low-level momentum fluxes established during the earliest stages of development. These fluxes also serve as a focal point for the present study.

For a realistic, zonally symmetric jet on the sphere, the normal-mode life cycle of a short wave (wavenumber 8) under both dry and moist conditions is described. Latent heating intensifies the low pressure system and frontal zones but does not alter the broader details of the life cycle. The normal modes have predominantly equatorward momentum fluxes, in contrast to the mainly poleward momentum fluxes of long waves. The short waves are more meridionally confined. The equatorward momentum fluxes direct the waves toward cyclonic breaking. The feedback with the zonal-mean wind, the so-called barotropic governor, is less effective than in the standard long-wave life cycle, which ends in anticyclonic breaking. However, in contrast to long-wave life cycles that are “engineered” to produce equatorward momentum fluxes, relatively little potential vorticity and surface temperature anomaly roll up into isolated vortices. Therefore, the short wave undergoes protracted barotropic decay leading to complete zonalization. Short waves also have a brief period of baroclinic decay due to cold advection over the surface cyclones.

Eliassen–Palm cross sections for the short-wave life cycles show the usual combination of upward and meridional propagation of wave activity. However, the meridional propagation is mainly toward the pole and there is a consequent zonal-mean deceleration at high latitudes. These details are included in the proposed classification of equilibration scenarios.

* Current affiliation: Climate and Integrated System Modeling, Lawrence Livermore National Laboratory, Livermore, California.

Corresponding author address: Dr. Balasubramanian Govindasamy, Climate and Integrated System Modeling, Lawrence Livermore National Laboratory, P.O. Box 808, L-256, Livermore, CA 94551- 9900.

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  • Balasubramanian, G., and M. K. Yau, 1994a: Baroclinic instability in a two layer model with parameterized slantwise convection. J. Atmos. Sci.,51, 971–990.

  • ——, and ——, 1994b: The effects of convection on a simulated marine cyclone. J. Atmos. Sci.,51, 2397–2417.

  • ——, and ——, 1996: The life cycle of a simulated marine cyclone:Energetics and PV diagnostics. J. Atmos. Sci.,53, 639–653.

  • ——, and S. T. Garner, 1997: The role of eddy momentum fluxes in shaping the life cycle of a baroclinic wave. J. Atmos. Sci.,54, 510–533.

  • Bourke, W., 1974: A multilevel spectral model. Part I: Formulation and hemispheric integrations. Mon. Wea. Rev.,102, 687–701.

  • Chang, K. M., and I. Orlanski, 1993: On the dynamics of a storm track. J. Atmos. Sci.,50, 999–1015.

  • Danard, M. B., 1964: On the influence of released latent heat on cyclone development. J. Appl. Meteor.,3, 27–37.

  • ——, and G. E. Ellenton, 1980: Physical influences on east coast cyclogenesis. Atmos.-Ocean,18, 65–82.

  • Davis, C. A., and K. A. Emanuel, 1991: Potential vorticity diagnostics of cyclogenesis. Mon. Wea. Rev.,119, 1929–1953.

  • Edmon, H. J., B. J. Hoskins, and M. E. McIntyre, 1980: Eliassen–Palm cross sections for the troposphere. J. Atmos. Sci.,37, 2600–2616.

  • Emanuel, K. A., M. Fantini, and A. J. Thorpe, 1987: Baroclinic instability in an environment of small stability to slantwise moist convection. J. Atmos. Sci.,44, 1559–1573.

  • Fantini, M., 1991: Baroclinic instability and induced air-heat exchange. Tellus,43A, 285–294.

  • ——, 1995: Moist Eady waves in a quasigeostrophic three-dimensional model. J. Atmos. Sci.,52, 2473–2485.

  • Feldstein, S. B., and I. M. Held, 1989: Barotropic decay of baroclinic waves in a two-layer beta plane model. J. Atmos. Sci.,46, 3416–3430.

  • Gall, R. L., 1976: The effects of released latent heat in growing baroclinic waves. J. Atmos. Sci.,33, 1686–1701.

  • Gutowski, W. J., L. E. Bronscome, and D. S. Stewart, 1992: Life cycles of moist baroclinic eddies. J. Atmos. Sci.,49, 306–319.

  • Gyakum, J. R., 1983a: On the evolution of the QE II storm. Part I: Synoptic aspects. Mon. Wea. Rev.,111, 1137–1135.

  • ——, 1983b: On the evolution of the QE II storm. Part II: Dynamic and thermodynamic structure. Mon. Wea. Rev.,111, 1156–1173.

  • Hedley, M., and M. K. Yau, 1991: Anelastic modeling of explosive cyclogenesis. J. Atmos. Sci.,48, 711–727.

  • Held, I. M., and B. J. Hoskins, 1985: Large scale eddies and the general circulation of the troposphere. Advances in Geophysics, Vol. 28A, Academic Press, 3–31.

  • ——, and M. J. Suarez, 1994: A proposal for the intercomparison of the dynamical cores of atmospheric general circulation models. Bull. Amer. Meteor. Soc.,75, 1825–1835.

  • ——, and V. D. Lavichev, 1996: A scaling theory for horizontally homogeneous baroclinically unstable flow on a beta plane. J. Atmos. Sci.,53, 946–956.

  • Holton, J. R., 1992: An Introduction to Dynamic Meteorology. 3d ed. Academic Press, 511 pp.

  • Hoskins, B. J., M. E. McIntyre, and A. W. Robertson, 1985: On the use and significance of isentropic potential vorticity maps. Quart. J. Roy. Meteor. Soc.,111, 877–946.

  • James, I. N., 1987: Suppression of baroclinic instability in horizontally sheared flows. J. Atmos. Sci.,44, 3710–3720.

  • ——, and L. J. Gray, 1986: Concerning the effect of surface drag on the circulation of a baroclinic planetary atmosphere. Quart. J. Roy. Meteor. Soc.,112, 1231–1250.

  • Joly, A., and A. J. Thorpe, 1991: Warm and occluded fronts in two dimensional moist baroclinic instability. Quart. J. Roy. Meteor. Soc.,115, 513–534.

  • Kida, S., 1981: Motion of an elliptic vortex in a uniform shear flow. J. Phys. Soc. Japan,50, 3517–3520.

  • Kuo, Y. H., M. A. Shapiro, and E. G. Donall, 1991: The interaction between baroclinic and diabatic processes in a numerical simulation of a rapidly intensifying marine cyclone. Mon. Wea. Rev.,119, 457–476.

  • Lee, S., and I. M. Held, 1993: Baroclinic wave packets in models and observations. J. Atmos. Sci.,50, 1413–1428.

  • ——, and S. Feldstein, 1996: Two types of wave breaking in an aquaplanet GCM. J. Atmos. Sci.,53, 842–856.

  • Montgomery, M. T., and B. F. Farrell, 1991: Moist surface frontogenesis associated with interior potential vorticity anomalies in a semigeostrophic model. J. Atmos. Sci.,48, 2484–2505.

  • Nakamura, H., 1992: Midwinter suppression of baroclinic wave activity in the Pacific. J. Atmos. Sci.,49, 1629–1642.

  • ——, 1993: Momentum flux, flow symmetry, and the nonlinear barotropic governor. J. Atmos. Sci.,50, 2159–2179.

  • Neiman, P. J., and M. A. Shapiro, 1993a: The life cycle of an extra- tropical cyclone. Part I: Frontal evolution and thermodynamic air–sea interaction. Mon. Wea. Rev.,121, 2153–2176.

  • ——, and ——, 1993b: The life cycle of an extra-tropical cyclone. Part II: Mesoscale structure and diagnostics. Mon. Wea. Rev.,121, 2177–2199.

  • Orlanski, I., and J. Katzfey, 1987: Sensitivity of model simulations for a coastal cyclone. Mon. Wea. Rev.,115, 2792–2821.

  • ——, ——, C. Menendez, and M. Marino, 1991: Simulation of an extratropical cyclone in the Southern Hemisphere: Model sensitivity. J. Atmos. Sci.,48, 2293–2311.

  • Paran, V., and I. M. Held, 1996: The diffusive approximation for eddy fluxes in baroclinically unstable jets. J. Atmos. Sci.,53, 1262–1272.

  • Parker, D. J., and A. J. Thorpe, 1995: Conditional convective heating in a baroclinic atmosphere. A model of convective frontogenesis. J. Atmos. Sci.,52, 1699–1711.

  • Peixoto, J. P., and A. H. Oort, 1992: Physics of Climate. American Institute of Physics, 520 pp.

  • Randel, W. J., and J. L. Stanford, 1985: The observed life cycle of a baroclinic instability. J. Atmos. Sci.,42, 1364–1373.

  • ——, and I. M. Held, 1991: Phase speed spectra of transient eddy fluxes and critical layer absorption. J. Atmos. Sci., 48, 688–697.

  • Robert, A. F., 1966: The integration of a low order spectral form of the primitive meteorological equations. J. Meteor. Soc. Japan,44, 237–245.

  • Shapiro, M. A., and D. Keyser, 1990: Fronts, jet streams and the tropopause. Extratropical Cyclones: The Erik Palmén Memorial Volume, C. W. Newton and E. O. Holopainen, Eds., Amer. Meteor. Soc., 262 pp.

  • Simmons, A. J., and B. J. Hoskins, 1976: Baroclinic instability on the sphere: Normal modes of the primitive and quasi-geostrophic equations. J. Atmos. Sci.,33, 1454–1477.

  • ——, and ——, 1978: The life cycles of some nonlinear baroclinic waves. J. Atmos. Sci.,35, 414–432.

  • Snyder, C., W. C. Skamarock, and R. Rotunno, 1991: A comparison of primitive-equation and semigeostrophic simulations of baroclinic waves. J. Atmos. Sci.,48, 2179–2194.

  • Thorncroft, C. D., B. J. Hoskins, and M. E. McIntyre, 1993: Two paradigms of baroclinic wave life cycle behavior. Quart. J. Roy. Meteor. Soc.,119, 17–55.

  • Thorpe, A. J., and K. A. Emanuel, 1985: Frontogenesis in the presence of small moist symmetric stability. J. Atmos. Sci.,42, 1809–1824.

  • Tracton, M. S., 1973: The role of cumulus convection in the development of extratropical cyclone. Mon. Wea. Rev.,101, 573–593.

  • Wang, B., and A. Barcilon, 1986: Moist stability of a baroclinic zonal flow with conditionally unstable stratification. J. Atmos. Sci.,43, 705–719.

  • Whitaker, J. S., and C. Snyder, 1993: The effects of spherical geometry on the evolution of baroclinic waves. J. Atmos. Sci.,50, 597–612.

  • ——, and C. A. Davis, 1994: Cyclogenesis in a saturated environment. J. Atmos. Sci.,51, 889–907.

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