Editorial Type:
Article
Article Type:
Research Article

Why Do Model Tropical Cyclones Grow Progressively in Size and Decay in Intensity after Reaching Maturity?

Gerard Kilroy Meteorological Institute, Ludwig-Maximilians University of Munich, Munich, Germany

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Roger K. Smith Meteorological Institute, Ludwig-Maximilians University of Munich, Munich, Germany

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Michael T. Montgomery Department of Meteorology, Naval Postgraduate School, Monterey, California

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Print Publication:
01 Feb 2016
DOI:
https://doi.org/10.1175/JAS-D-15-0157.1
Page(s):
487–503
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Abstract

The long-term behavior of tropical cyclones in the prototype problem for cyclone intensification on an f plane is examined using a nonhydrostatic, three-dimensional numerical model. After reaching a mature intensity, the model storms progressively decay while both the inner-core size, characterized by the radius of the eyewall, and the size of the outer circulation—measured, for example, by the radius of the gale-force winds—progressively increase. This behavior is explained in terms of a boundary layer control mechanism in which the expansion of the swirling wind in the lower troposphere leads through boundary layer dynamics to an increase in the radii of forced eyewall ascent as well as to a reduction in the maximum tangential wind speed in the layer. These changes are accompanied by changes in the radial and vertical distribution of diabatic heating. As long as the aggregate effects of inner-core convection, characterized by the distribution of diabatic heating, are able to draw absolute angular momentum surfaces inward, the outer circulation will continue to expand. The quantitative effects of latitude on the foregoing processes are investigated also. The study provides new insight into the factors controlling the evolution of the size and intensity of a tropical cyclone. It provides also a plausible, and arguably simpler, explanation for the expansion of the inner core of Hurricane Isabel (2003) and Typhoon Megi (2010) than that given previously.

Corresponding author address: Dr. Gerard Kilroy, Meteorological Institute, Ludwig-Maximilians University of Munich, Theresienstr. 37, 80333 Munich, Germany. E-mail: gerard.kilroy@lmu.de

Abstract

The long-term behavior of tropical cyclones in the prototype problem for cyclone intensification on an f plane is examined using a nonhydrostatic, three-dimensional numerical model. After reaching a mature intensity, the model storms progressively decay while both the inner-core size, characterized by the radius of the eyewall, and the size of the outer circulation—measured, for example, by the radius of the gale-force winds—progressively increase. This behavior is explained in terms of a boundary layer control mechanism in which the expansion of the swirling wind in the lower troposphere leads through boundary layer dynamics to an increase in the radii of forced eyewall ascent as well as to a reduction in the maximum tangential wind speed in the layer. These changes are accompanied by changes in the radial and vertical distribution of diabatic heating. As long as the aggregate effects of inner-core convection, characterized by the distribution of diabatic heating, are able to draw absolute angular momentum surfaces inward, the outer circulation will continue to expand. The quantitative effects of latitude on the foregoing processes are investigated also. The study provides new insight into the factors controlling the evolution of the size and intensity of a tropical cyclone. It provides also a plausible, and arguably simpler, explanation for the expansion of the inner core of Hurricane Isabel (2003) and Typhoon Megi (2010) than that given previously.

Corresponding author address: Dr. Gerard Kilroy, Meteorological Institute, Ludwig-Maximilians University of Munich, Theresienstr. 37, 80333 Munich, Germany. E-mail: gerard.kilroy@lmu.de
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  • Bell, M. M., and M. T. Montgomery, 2008: Observed structure, evolution, and potential intensity of category 5 Hurricane Isabel (2003) from 12 to 14 September. Mon. Wea. Rev., 136, 2023–2046, doi:10.1175/2007MWR1858.1.

    • Search Google Scholar
    • Export Citation

  • Beven, J. L., and Coauthors, 2008: Atlantic hurricane season of 2005. Mon. Wea. Rev., 136, 1109–1173, doi:10.1175/2007MWR2074.1.

  • Bui, H. H., R. K. Smith, M. T. Montgomery, and J. Peng, 2009: Balanced and unbalanced aspects of tropical cyclone intensification. Quart. J. Roy. Meteor. Soc., 135, 1715–1731, doi:10.1002/qj.502.

    • Search Google Scholar
    • Export Citation

  • Chan, K. T. F., and J. C. L. Chan, 2015: Impacts of vortex intensity and outer winds on tropical cyclone size. Quart. J. Roy. Meteor. Soc., 141, 525–537, doi:10.1002/qj.2374.

    • Search Google Scholar
    • Export Citation

  • Chavas, D. R., and K. Emanuel, 2014: Equilibrium tropical cyclone size in an idealized state of axisymmetric radiative convective equilibrium. J. Atmos. Sci., 71, 1663–1680, doi:10.1175/JAS-D-13-0155.1.

    • Search Google Scholar
    • Export Citation

  • Davidson, N. E., 2010: On the intensification and recurvature of Tropical Cyclone Tracy (1974). Aust. Meteor. Oceanogr. J., 60, 169–177.

    • Search Google Scholar
    • Export Citation

  • Dean, L., K. A. Emanuel, and D. R. Chavas, 2009: On the size distribution of Atlantic tropical cyclones. Geophys. Res. Lett., 36, L14803, doi:10.1029/2009GL039051.

    • Search Google Scholar
    • Export Citation

  • DeMaria, M., and J. D. Pickle, 1988: A simplified system of equations for simulation of tropical cyclones. J. Atmos. Sci., 45, 1542–1554, doi:10.1175/1520-0469(1988)045<1542:ASSOEF>2.0.CO;2.

    • Search Google Scholar
    • Export Citation

  • Dunnavan, G. M., and J. W. Diercks, 1980: An analysis of Super Typhoon Tip (October 1979). Mon. Wea. Rev., 108, 1915–1923, doi:10.1175/1520-0493(1980)108<1915:AAOSTT>2.0.CO;2.

    • Search Google Scholar
    • Export Citation

  • Eliassen, A., 1951: Slow thermally or frictionally controlled meridional circulation in a circular vortex. Astrophys. Norv., 5, 19–60.

    • Search Google Scholar
    • Export Citation

  • Emanuel, K. A., 2004: Tropical cyclone energetics and structure. Atmospheric Turbulence and Mesoscale Meteorology: Scientific Research Inspired by Doug Lilly, E. Fedorovich, R. Rotunno, and B. Stevens, Eds., Cambridge University Press, 165–192.

    • Search Google Scholar
    • Export Citation

  • Frisius, T., 2015: What controls the size of a tropical cyclone? Investigations with an axisymmetric model. Quart. J. Roy. Meteor. Soc., 141, 2457–2470, doi:10.1002/qj.2537.

    • Search Google Scholar
    • Export Citation

  • Fudeyasu, H., and Y. Wang, 2011: Balanced contribution to the intensification of a tropical cyclone simulated in TCM4: Outer-core spinup process. J. Atmos. Sci., 68, 430–449, doi:10.1175/2010JAS3523.1.

    • Search Google Scholar
    • Export Citation

  • 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, 121 pp. [Available online at http://nldr.library.ucar.edu/repository/assets/technotes/TECH-NOTE-000-000-000-214.pdf.]

  • Hakim, G. J., 2011: The mean state of axisymmetric hurricanes in statistical equilibrium. J. Atmos. Sci., 68, 1364–1376, doi:10.1175/2010JAS3644.1.

    • Search Google Scholar
    • Export Citation

  • Kepert, J. D., 2006a: Observed boundary layer wind structure and balance in the hurricane core. Part I: Hurricane Georges. J. Atmos. Sci., 63, 2169–2193, doi:10.1175/JAS3745.1.

    • Search Google Scholar
    • Export Citation

  • Kepert, J. D., 2006b: Observed boundary layer wind structure and balance in the hurricane core. Part II: Hurricane Mitch. J. Atmos. Sci., 63, 2194–2211, doi:10.1175/JAS3746.1.

    • Search Google Scholar
    • Export Citation

  • Li, T., X. Ge, M. Peng, and W. Wang, 2012: Dependence of tropical cyclone intensification on the Coriolis parameter. Trop. Cyclone Res. Rev., 1, 242–253.

    • Search Google Scholar
    • Export Citation

  • Lussier, L. L., B. Rutherford, M. T. Montgomery, M. A. Boothe, and T. J. Dunkerton, 2015: Examining the roles of the easterly wave critical layer and vorticity accretion during the tropical cyclogenesis of Hurricane Sandy. Mon. Wea. Rev., 143, 1703–1722, doi:10.1175/MWR-D-14-00001.1.

    • Search Google Scholar
    • Export Citation

  • Mapes, B. E., and P. Zuidema, 1996: Radiative–dynamical consequences of dry tongues in the tropical troposphere. J. Atmos. Sci., 53, 620–638, doi:10.1175/1520-0469(1996)053<0620:RDCODT>2.0.CO;2.

    • Search Google Scholar
    • Export Citation

  • Merrill, R. T., 1984: A comparison of large and small tropical cyclones. Mon. Wea. Rev., 112, 1408–1418, doi:10.1175/1520-0493(1984)112<1408:ACOLAS>2.0.CO;2.

    • Search Google Scholar
    • Export Citation

  • Möller, J. D., and L. J. Shapiro, 2002: Balanced contributions to the intensification of Hurricane Opal as diagnosed from a GFDL model forecast. Mon. Wea. Rev., 130, 1866–1881, doi:10.1175/1520-0493(2002)130<1866:BCTTIO>2.0.CO;2.

    • Search Google Scholar
    • Export Citation

  • Montgomery, M. T., and R. K. Smith, 2014: Paradigms for tropical cyclone intensification. Aust. Meteor. Oceanogr. J., 64, 37–66. [Available online at http://www.bom.gov.au/amoj/docs/2014/montgomery_hres.pdf.]

    • Search Google Scholar
    • Export Citation

  • Montgomery, M. T., M. E. Nichols, T. A. Cram, and A. B. Saunders, 2006: A vortical hot tower route to tropical cyclogenesis. J. Atmos. Sci., 63, 355–386, doi:10.1175/JAS3604.1.

    • Search Google Scholar
    • Export Citation

  • Montgomery, M. T., J. Persing, and R. K. Smith, 2014: Putting to rest WISHE-ful misconceptions for tropical cyclone intensification. J. Adv. Model. Earth Syst., 7, 92–109, doi:10.1002/2014MS000362.

    • Search Google Scholar
    • Export Citation

  • Nguyen, V. S., R. K. Smith, and M. T. Montgomery, 2008: Tropical-cyclone intensification and predictability in three dimensions. Quart. J. Roy. Meteor. Soc., 134, 563–582, doi:10.1002/qj.235.

    • Search Google Scholar
    • Export Citation

  • Persing, J., M. T. Montgomery, J. McWilliams, and R. K. Smith, 2013: Asymmetric and axisymmetric dynamics of tropical cyclones. Atmos. Chem. Phys., 13, 12 299–12 341, doi:10.5194/acp-13-12299-2013.

    • Search Google Scholar
    • Export Citation

  • Rappin, E. D., M. C. Morgan, and G. J. Tripoli, 2011: The impact of outflow environment on tropical cyclone intensification and structure. J. Atmos. Sci., 68, 177–194, doi:10.1175/2009JAS2970.1.

    • Search Google Scholar
    • Export Citation

  • Rotunno, R., and K. A. Emanuel, 1987: An air–sea interaction theory for tropical cyclones. Part II: Evolutionary study using a nonhydrostatic axisymmetric numerical model. J. Atmos. Sci., 44, 542–561, doi:10.1175/1520-0469(1987)044<0542:AAITFT>2.0.CO;2.

    • Search Google Scholar
    • Export Citation

  • Sanger, N. T., M. T. Montgomery, R. K. Smith, and M. M. Bell, 2014: An observational study of tropical cyclone spinup in Supertyphoon Jangmi (2008) from 24 to 27 September. Mon. Wea. Rev., 142, 3–28, doi:10.1175/MWR-D-12-00306.1.

    • Search Google Scholar
    • Export Citation

  • Smith, R. K., 2006: Accurate determination of a balanced axisymmetric vortex in a compressible atmosphere. Tellus, 58A, 98–103, doi:10.1111/j.1600-0870.2006.00149.x.

    • Search Google Scholar
    • Export Citation

  • Smith, R. K., and M. T. Montgomery, 2010: Hurricane boundary-layer theory. Quart. J. Roy. Meteor. Soc., 136, 1665–1670, doi:10.1002/qj.679.

    • Search Google Scholar
    • Export Citation

  • Smith, R. K., C. W. Schmidt, and M. T. Montgomery, 2011: Dynamical constraints on the intensity and size of tropical cyclones. Quart. J. Roy. Meteor. Soc., 137, 1841–1855, doi:10.1002/qj.862.

    • Search Google Scholar
    • Export Citation

  • Smith, R. K., M. T. Montgomery, and J. Persing, 2014: On steady-state tropical cyclones. Quart. J. Roy. Meteor. Soc., 140, 2638–2649, doi:10.1002/qj.2329.

    • Search Google Scholar
    • Export Citation

  • Smith, R. K., G. Kilroy, and M. T. Montgomery, 2015: Why do model tropical cyclones intensify more rapidly at low latitudes? J. Atmos. Sci., 72, 1783–1804, doi:10.1175/JAS-D-14-0044.1.

    • Search Google Scholar
    • Export Citation

  • Wang, Y., and H. Wang, 2013: The inner-core size increase of Typhoon Megi (2010) during its rapid intensification phase. Trop. Cyclone Res. Rev., 2, 65–80, doi:10.6057/2013TCRR02.01.

    • Search Google Scholar
    • Export Citation

  • Willoughby, H. E., 1979: Forced secondary circulations in hurricanes. J. Geophys. Res., 84, 3173–3183, doi:10.1029/JC084iC06p03173.

  • Xu, J., and Y. Wang, 2010: Sensitivity of tropical cyclone inner-core size and intensity to the radial distribution of surface entropy flux. J. Atmos. Sci., 67, 1831–1852, doi:10.1175/2010JAS3387.1.

    • Search Google Scholar
    • Export Citation

  • Yamasaki, M., 1968: Numerical simulation of tropical cyclone development with the use of primitive equations. J. Meteor. Soc. Japan, 46, 178–201.

    • Search Google Scholar
    • Export Citation
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