• Black, M. L., , and H. W. Willoughby, 1992: The concentric eyewall cycle of Hurricane Gilbert. Mon. Wea. Rev., 120 , 947957.

  • Dodge, P., , R. W. Burpee, , and F. D. Marks Jr., 1999: The kinematic structure of a hurricane with sea level pressure less than 900 mb. Mon. Wea. Rev., 127 , 9871004.

    • Search Google Scholar
    • Export Citation
  • Dritschel, D. G., 1985: The stability and energetics of corotating uniform vortices. J. Fluid Mech., 157 , 95134.

  • Dritschel, D. G., 1988: Contour surgery: A topological reconnection scheme for extended integrations using contour dynamics. J. Comput. Phys., 77 , 240266.

    • Search Google Scholar
    • Export Citation
  • Dritschel, D. G., 1989: Contour dynamics and contour surgery: Numerical algorithms for extended, high-resolution modeling of vortex dynamics in two-dimensional, inviscid, incompressible flows. Comput. Phys. Rep., 10 , 77146.

    • Search Google Scholar
    • Export Citation
  • Flatau, M., , and D. E. Stevens, 1993: The role of outflow-layer instabilities in tropical cyclone motion. J. Atmos. Sci., 50 , 17211733.

    • Search Google Scholar
    • Export Citation
  • Holland, G. J., , and M. Lander, 1993: The meandering nature of tropical cyclone tracks. J. Atmos. Sci., 50 , 12541266.

  • Holliday, C. R., 1977: Double intensification of Typhoon Gloria, 1974. Mon. Wea. Rev., 105 , 523528.

  • Itano, T., , and H. Ishikawa, 2002: Effect of negative vorticity on the formation of multiple structure of natural vortices. J. Atmos. Sci., 59 , 32543262.

    • Search Google Scholar
    • Export Citation
  • Itano, T., , G. Naito, , and M. Oda, 2002: Analysis of elliptical eye of Typhoon Herb (T9609) (in Japanese with English abstract). Sci. Eng. Rep. Natl. Def. Acad., 39 , 917.

    • Search Google Scholar
    • Export Citation
  • Jones, S. C., 1995: The evolution of vortices in vertical shear. Part I: Initially barotropic vortices. Quart. J. Roy. Meteor. Soc., 121 , 821851.

    • Search Google Scholar
    • Export Citation
  • Jordan, C. L., 1966: Surface pressure variations at coastal stations during the period of irregular motion of Hurricane Carla of 1961. Mon. Wea. Rev., 94 , 454458.

    • Search Google Scholar
    • Export Citation
  • Kossin, J. P., , W. H. Schubert, , and M. T. Montgomery, 2000: Unstable interactions between a hurricane’s primary eyewall and a secondary ring of enhanced vorticity. J. Atmos. Sci., 57 , 38933917.

    • Search Google Scholar
    • Export Citation
  • Muramatsu, T., 1986: Trochoidal motion of the eye of Typhoon 8019. J. Meteor. Soc. Japan, 64 , 259272.

  • Nolan, D. S., , M. T. Montgomery, , and L. D. Grasso, 2001: The wavenumber-one instability and trochoidal motion of hurricane-like vortices. J. Atmos. Sci., 58 , 32433270.

    • Search Google Scholar
    • Export Citation
  • Oda, M., , T. Itano, , G. Naito, , M. Nakanishi, , and K. Tomine, 2005: Destabilization of the symmetric vortex and the formation of the elliptical eye of Typhoon Herb. J. Atmos. Sci., 62 , 29652976.

    • Search Google Scholar
    • Export Citation
  • Prieto, R., , B. D. McNoldy, , S. R. Fulton, , and W. H. Schubert, 2003: A classification of binary tropical-cyclone-like vortex interactions. Mon. Wea. Rev., 131 , 26562666.

    • Search Google Scholar
    • Export Citation
  • Ritchie, E. A., , and G. J. Holland, 1993: On the interaction of tropical-cyclone-scale vortices. II: Discrete vortex patches. Quart. J. Roy. Meteor. Soc., 119 , 13631379.

    • Search Google Scholar
    • Export Citation
  • Roux, F., , and N. Viltard, 1995: Structure and evolution of Hurricane Claudette on 7 September 1991 from air Doppler radar observation. Part I: Kinematics. Mon. Wea. Rev., 123 , 26112639.

    • Search Google Scholar
    • Export Citation
  • Samsury, C. E., , and E. J. Zipser, 1995: Secondary wind maxima in hurricanes: Airflow and relationship to rainbands. Mon. Wea. Rev., 123 , 35023517.

    • Search Google Scholar
    • Export Citation
  • Willoughby, H. E., , J. A. Clos, , and M. G. Shoreibah, 1982: Concentric eye walls, secondary wind maxima, and the evolution of the hurricane vortex. J. Atmos. Sci., 39 , 395411.

    • Search Google Scholar
    • Export Citation
  • Wu, C-C., , and K. A. Emanuel, 1993: Interaction of a baroclinic vortex with background shear: Application to hurricane movement. J. Atmos. Sci., 50 , 6276.

    • Search Google Scholar
    • Export Citation
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Interaction of an Asymmetric Double Vortex and Trochoidal Motion of a Tropical Cyclone with the Concentric Eyewall Structure

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  • 1 Air Weather Group, Japan Air Self Defense Force, Fuchu, Tokyo, Japan
  • | 2 Department of Earth and Ocean Sciences, National Defense Academy, Yokosuka, Kanagawa, Japan
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Abstract

Radar echo images demonstrate that mature tropical cyclones frequently have a concentric eyewall structure, which consists of the inner eyewall, echo-free moat, and outer eyewall regions. Near the inner and outer eyewalls, well-defined wind maxima are generally observed. This indicates that two large vertical vorticity regions exist just inside radii of the two wind maxima near the inner and outer eyewalls. Therefore, the concentric eyewall structure can be considered to be a double vortex composed of the inner vortex and the outer vortex ring. In this study, the contour dynamics model is used on the f plane to analyze the characteristics of flows with either a symmetric double vortex or an asymmetric one, and examined the relationship between the movement of the inner vortex in an asymmetric double vortex and a trochoidal motion of a tropical cyclone with an asymmetric concentric eyewall structure.

Results show that, depending on the degree of an interaction of a double vortex, the evolution of the inner vortex is classified into three patterns: the first is that the center of the inner vortex is stationary, which is seen only for the symmetric double vortex; the second is that the track of the center of the inner vortex draws a circle; and the third is that it draws a spiral. A numerical experiment based on an observed flow around Typhoon Herb was also performed. The time evolution of the double vortex is very similar to that of radar echo intensity of Typhoon Herb. Also the rotation period and amplitude of the inner vortex in the numerical experiment were comparable with those of the trochoidal motion in the observation. These suggest that, in tropical cyclones with the concentric eyewall structure, the interaction of an asymmetric double vortex can become a cause of trochoidal motion.

Corresponding author address: Dr. Masahito Oda, Weather Center, Air Weather Group, Japan Air Self Defense Force, 1-5-5 Sengen-cho, Fuchu, Tokyo 183-8521, Japan. Email: hiro-ayu@f2.dion.ne.jp

Abstract

Radar echo images demonstrate that mature tropical cyclones frequently have a concentric eyewall structure, which consists of the inner eyewall, echo-free moat, and outer eyewall regions. Near the inner and outer eyewalls, well-defined wind maxima are generally observed. This indicates that two large vertical vorticity regions exist just inside radii of the two wind maxima near the inner and outer eyewalls. Therefore, the concentric eyewall structure can be considered to be a double vortex composed of the inner vortex and the outer vortex ring. In this study, the contour dynamics model is used on the f plane to analyze the characteristics of flows with either a symmetric double vortex or an asymmetric one, and examined the relationship between the movement of the inner vortex in an asymmetric double vortex and a trochoidal motion of a tropical cyclone with an asymmetric concentric eyewall structure.

Results show that, depending on the degree of an interaction of a double vortex, the evolution of the inner vortex is classified into three patterns: the first is that the center of the inner vortex is stationary, which is seen only for the symmetric double vortex; the second is that the track of the center of the inner vortex draws a circle; and the third is that it draws a spiral. A numerical experiment based on an observed flow around Typhoon Herb was also performed. The time evolution of the double vortex is very similar to that of radar echo intensity of Typhoon Herb. Also the rotation period and amplitude of the inner vortex in the numerical experiment were comparable with those of the trochoidal motion in the observation. These suggest that, in tropical cyclones with the concentric eyewall structure, the interaction of an asymmetric double vortex can become a cause of trochoidal motion.

Corresponding author address: Dr. Masahito Oda, Weather Center, Air Weather Group, Japan Air Self Defense Force, 1-5-5 Sengen-cho, Fuchu, Tokyo 183-8521, Japan. Email: hiro-ayu@f2.dion.ne.jp

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