Editorial Type:
Article
Article Type:
Research Article

Dynamic Instabilities of Simulated Hurricane-like Vortices and Their Impacts on the Core Structure of Hurricanes. Part II: Moist Experiments

Young C. Kwon NOAA/NCEP/EMC, Camp Springs, Maryland

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William M. Frank Department of Meteorology, The Pennsylvania State University, University Park, Pennsylvania

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Print Publication:
01 Jan 2008
DOI:
https://doi.org/10.1175/2007JAS2132.1
Page(s):
106–122
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Abstract

The energy flows of a simulated moist hurricane-like vortex are analyzed to examine the processes that change the intensity and structure of tropical cyclones. The moist vortex used in this study is initially axisymmetric on an f plane and is placed on a uniform surface—an ocean with constant sea surface temperature of 29°C. Two simulations are performed using the following different environmental flows: one in a calm environment and the other in weak environmental vertical shear. The differences between the intensities and structures of the two simulated vortices are discussed in terms of energy flows.

While the structure and intensity of the vortex without shear are relatively steady, those of the vortex with shear experience dramatic changes. The sheared vortex shows delayed weakening, persistent wavenumber 1 asymmetry with maximum rainfall on the downshear left side, and top-down breakdown. In both vortices barotropic energy conversion is stronger than baroclinic energy conversion. However, baroclinic processes in the upper levels of the sheared vortex play an important role in weakening the vortex. The energy flow diagram and the cross section of energy conversion terms show the existence of multiple baroclinic eddy life cycles at the upper levels of the sheared vortex. The activity of the baroclinic eddies continues until ventilation of the upper-level warm-core structure is sufficient to weaken the sheared vortex.

Corresponding author address: Young C. Kwon, NOAA/NCEP/EMC, 5200 Auth Road, Camp Springs, MD 20746. Email: young.kwon@noaa.gov

Abstract

The energy flows of a simulated moist hurricane-like vortex are analyzed to examine the processes that change the intensity and structure of tropical cyclones. The moist vortex used in this study is initially axisymmetric on an f plane and is placed on a uniform surface—an ocean with constant sea surface temperature of 29°C. Two simulations are performed using the following different environmental flows: one in a calm environment and the other in weak environmental vertical shear. The differences between the intensities and structures of the two simulated vortices are discussed in terms of energy flows.

While the structure and intensity of the vortex without shear are relatively steady, those of the vortex with shear experience dramatic changes. The sheared vortex shows delayed weakening, persistent wavenumber 1 asymmetry with maximum rainfall on the downshear left side, and top-down breakdown. In both vortices barotropic energy conversion is stronger than baroclinic energy conversion. However, baroclinic processes in the upper levels of the sheared vortex play an important role in weakening the vortex. The energy flow diagram and the cross section of energy conversion terms show the existence of multiple baroclinic eddy life cycles at the upper levels of the sheared vortex. The activity of the baroclinic eddies continues until ventilation of the upper-level warm-core structure is sufficient to weaken the sheared vortex.

Corresponding author address: Young C. Kwon, NOAA/NCEP/EMC, 5200 Auth Road, Camp Springs, MD 20746. Email: young.kwon@noaa.gov

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  • Blackadar, A. K., 1976: Modeling the nocturnal boundary layer. Preprints. Third Symp. on Atmospheric Turbulence and Air Quality, Raleigh, NC, Amer. Meteor. Soc., 46–49.

    • Search Google Scholar
    • Export Citation

  • Blackadar, A. K., 1979: High resolution models of the planetary boundary layer. Advances in Environmental Science and Engineering, Vol. 1, Gordon and Breach Science, 50–85.

    • Search Google Scholar
    • Export Citation

  • Camp, J. P., and M. T. Montgomery, 2001: Hurricane maximum intensity: Past and Present. Mon. Wea. Rev., 129 , 1704–1717.

  • Chen, Y., and M. K. Yau, 2001: Spiral bands in a simulated hurricane. Part I: Vortex Rossby wave verification. J. Atmos. Sci., 58 , 2128–2145.

    • Search Google Scholar
    • Export Citation

  • Daida, S. K., and G. M. Barnes, 2000: The eyewall of category 1 Hurricane Paine near landfall. Preprints, 24th Conf. on Hurricane and Tropical Meteorology, Fort Lauderdale, FL, Amer. Meteor. Soc., 414–415.

  • Emanuel, K. A., 1988: The maximum potential intensity of hurricanes. J. Atmos. Sci., 45 , 1143–1155.

  • Emanuel, K. A., 2005: Increasing destructiveness of tropical cyclones over the past 30 years. Nature, 436 , 686–688.

  • Frank, W. M., and E. A. Ritchie, 1999: Effects of environmental flow upon tropical cyclone structure. Mon. Wea. Rev., 127 , 2044–2061.

  • Frank, W. M., and E. A. Ritchie, 2001: Effects of vertical wind shear on the intensity and structure of numerically simulated hurricanes. Mon. Wea. Rev., 129 , 2249–2269.

    • Search Google Scholar
    • Export Citation

  • Gray, W. M., 1968: Global view of the origin of tropical disturbances and storms. Mon. Wea. Rev., 96 , 669–700.

  • Grell, G. A., J. Dudhia, and D. R. Stauffer, 1995: A description of the fifth generation Penn State/NCAR mesoscale model (MM5). NCAR Tech Note NCAR/TN-398+STR, 138 pp.

  • Guinn, T. A., and W. H. Schubert, 1993: Hurricane spiral bands. J. Atmos. Sci., 50 , 3380–3403.

  • Holland, G. J., 1997: The maximum potential intensity of tropical cyclones. J. Atmos. Sci., 54 , 2519–2541.

  • Jones, S. C., 1995: The evolution of vortices in vertical shear: Initially barotropic vortices. Quart. J. Roy. Meteor. Soc., 121 , 821–851.

    • Search Google Scholar
    • Export Citation

  • Kain, J. S., and J. M. Fritsch, 1990: A one-dimensional entraining/detraining plume model and its application in convective parameterization. J. Atmos. Soc., 47 , 2784–2802.

    • Search Google Scholar
    • Export Citation

  • Knutson, T. R., and R. E. Tuleya, 2004: Impact of CO2-induced warming on simulated hurricane intensity and precipitation: Sensitivity to the choice of climate mode and convective parameterization. J. Climate, 17 , 3477–3495.

    • Search Google Scholar
    • Export Citation

  • Kossin, J. P., and M. D. Eastin, 2001: Two distinct regimes in the kinematic and thermodynamic of the hurricane eye and eyewall. J. Atmos. Sci., 58 , 1079–1090.

    • Search Google Scholar
    • Export Citation

  • Kossin, J. P., and W. H. Schubert, 2001: Mesovortices, polygonal flow patterns, and rapid pressure falls in hurricane-like vortices. J. Atmos. Sci., 58 , 1079–1090.

    • Search Google Scholar
    • Export Citation

  • Krishnamurti, T. N., S. Pattnaik, L. Stefanova, T. S. V. Vijaya Kumar, B. P. Mackey, A. J. O’Shay, and R. J. Pasch, 2005: Hurricane intensity issue. Mon. Wea. Rev., 133 , 1886–1912.

    • Search Google Scholar
    • Export Citation

  • Kuo, H. C., R. T. Williams, and J-H. Chen, 1999: A possible mechanism for the eye rotation of Typhoon Herb. J. Atmos. Sci., 56 , 1659–1673.

    • Search Google Scholar
    • Export Citation

  • Kwon, Y. C., and W. M. Frank, 2005: Dynamic instabilities of simulated hurricane-like vortices and their impacts on the core structure of hurricanes. Part I: Dry experiments. J. Atmos. Sci., 62 , 3955–3973.

    • Search Google Scholar
    • Export Citation

  • Landsea, C. W., N. Nicholls, W. M. Gray, and L. A. Avila, 1996: Downward trend in the frequency of intense Atlantic hurricanes during the past five decades. Geophys. Res. Lett., 23 , 1697–1700.

    • Search Google Scholar
    • Export Citation

  • Malkus, J. S., and H. Riehl, 1960: On the dynamics and energy transformations in steady-state hurricanes. Tellus, 12 , 1–20.

  • McBride, J. L., and R. Zehr, 1981: Observational analysis of tropical cyclone formation. Part II: Comparison of non-developing versus developing systems. J. Atmos. Sci., 38 , 1132–1151.

    • Search Google Scholar
    • Export Citation

  • Möller, J. D., and M. T. Montgomery, 1999: Vortex Rossby waves and hurricane intensification in a barotropic model. J. Atmos. Sci., 56 , 1674–1687.

    • Search Google Scholar
    • Export Citation

  • Möller, J. D., and M. T. Montgomery, 2000: Tropical cyclone evolution via potential vorticity anomalies in a three-dimensional balanced model. J. Atmos. Sci., 57 , 3366–3387.

    • Search Google Scholar
    • Export Citation

  • Möller, J. D., and L. J. Shapiro, 2005: Influences of asymmetric heating on hurricane evolution in the MM5. J. Atmos. Sci., 62 , 3974–3992.

    • Search Google Scholar
    • Export Citation

  • Montgomery, M. T., and R. J. Kallenbach, 1997: A theory for vortex Rossby waves and its application to spiral bands and intensity changes in hurricanes. Quart. J. Roy. Meteor. Soc., 123 , 435–465.

    • Search Google Scholar
    • Export Citation

  • Nolan, D. S., and M. T. Montgomery, 2002: Nonhydrostatic, three-dimensional perturbations to balanced, hurricane-like vortices. Part I: Linearized formulation, stability, and evolution. J. Atmos. Sci., 59 , 2989–3020.

    • Search Google Scholar
    • Export Citation

  • Nolan, D. S., and L. D. Grasso, 2003: Nonhydrostatic, three-dimensional perturbations to balanced, hurricane-like vortices. Part II: Symmetric response and nonlinear simulations. J. Atmos. Sci., 60 , 2717–2745.

    • Search Google Scholar
    • Export Citation

  • Pielke Jr., R. A., and C. W. Landsea, 1998: Normalized U.S. hurricane damage: 1925–95. Wea. Forecasting, 13 , 621–631.

  • Reasor, P. D., and M. T. Montgomery, 2001: Three-dimensional alignment and corotation of weak, TC-like vortices via linear vortex Rossby waves. J. Atmos. Sci., 58 , 2306–2330.

    • Search Google Scholar
    • Export Citation

  • Reasor, P. D., M. T. Montgomery, F. D. Marks Jr., and J. F. Gamache, 2000: Low-wavenumber structure and evolution of the hurricane inner core observed by airborne dual-Doppler radar. Mon. Wea. Rev., 128 , 1653–1680.

    • Search Google Scholar
    • Export Citation

  • Reasor, P. D., M. T. Montgomery, and L. G. Grasso, 2004: A new look at the problem of tropical cyclones in vertical shear flow: Vertical resiliency. J. Atmos. Soc., 61 , 3–22.

    • Search Google Scholar
    • Export Citation

  • Schubert, W. H., M. T. Montgomery, R. K. Taft, T. A. Guinn, S. R. Fulton, J. P. Kossin, and J. P. Edwards, 1999: Polygonal eyewalls, asymmetric eye contraction, and potential vorticity mixing in hurricanes. J. Atmos. Sci., 56 , 1197–1223.

    • Search Google Scholar
    • Export Citation

  • Wang, Y., 2001: An explicit simulation of tropical cyclones with a triply nested movable mesh primitive equation model-TCM3. Part I: Model description and control experiment. Mon. Wea. Rev., 129 , 1370–1394.

    • Search Google Scholar
    • Export Citation

  • Wang, Y., 2002a: Vortex Rossby waves in a numerically simulated tropical cyclone. Part I: Overall structure, potential vorticity, and kinetic energy budgets. J. Atmos. Sci., 59 , 1213–1238.

    • Search Google Scholar
    • Export Citation

  • Wang, Y., 2002b: Vortex Rossby waves in a numerically simulated tropical cyclone. Part II: The role in tropical cyclone structure and intensity changes. J. Atmos. Sci., 59 , 1239–1262.

    • Search Google Scholar
    • Export Citation

  • Webster, P. J., G. J. Holland, J. A. Curry, and H-R. Chang, 2005: Changes in tropical cyclone number, duration, and intensity in a warming environment. Science, 309 , 1844–1846.

    • Search Google Scholar
    • Export Citation

  • Wong, M. L., and J. C. L. Chan, 2004: Tropical cyclone intensity in vertical wind shear. J. Atmos. Soc., 61 , 1859–1876.

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