A New Look at the Binary Interaction: Potential Vorticity Diagnosis of the Unusual Southward Movement of Tropical Storm Bopha (2000) and Its Interaction with Supertyphoon Saomai (2000)

Chun-Chieh Wu Department of Atmospheric Sciences, National Taiwan University, Taipei, Taiwan

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Treng-Shi Huang Department of Atmospheric Sciences, National Taiwan University, Taipei, Taiwan

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Wei-Peng Huang Department of Atmospheric Sciences, National Taiwan University, Taipei, Taiwan

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Kun-Hsuan Chou Department of Atmospheric Sciences, National Taiwan University, Taipei, Taiwan

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Abstract

Tropical Storm Bopha (2000) showed a very unusual southward course parallel to the east coast of Taiwan, mainly steered by the circulation associated with Supertyphoon Saomai (2000) to Bopha's east. The binary interaction between the two typhoons is well demonstrated by the potential vorticity (PV) diagnosis. With the use of the piecewise PV inversion, this paper quantitatively evaluates how Bopha moved southward due to the binary interaction with Saomai. A newly proposed centroid-relative track, with the position weighting based on the steering flow induced by the PV anomaly associated with the other storm, is plotted to highlight such binary interaction processes. Note that the above analysis can be well used to understand the more complicated vortex merging and interacting processes between tropical cyclones either from observational data or numerical experiments. The results also shed some light on the prediction of nearby tropical cyclones.

Corresponding author address: Dr. Chun-Chieh Wu, Dept. of Atmospheric Sciences, National Taiwan University, 61, Ln. 144, Sec. 4, Keelung Rd., Taipei 106, Taiwan. Email: cwu@typhoon.as.ntu.edu.tw

Abstract

Tropical Storm Bopha (2000) showed a very unusual southward course parallel to the east coast of Taiwan, mainly steered by the circulation associated with Supertyphoon Saomai (2000) to Bopha's east. The binary interaction between the two typhoons is well demonstrated by the potential vorticity (PV) diagnosis. With the use of the piecewise PV inversion, this paper quantitatively evaluates how Bopha moved southward due to the binary interaction with Saomai. A newly proposed centroid-relative track, with the position weighting based on the steering flow induced by the PV anomaly associated with the other storm, is plotted to highlight such binary interaction processes. Note that the above analysis can be well used to understand the more complicated vortex merging and interacting processes between tropical cyclones either from observational data or numerical experiments. The results also shed some light on the prediction of nearby tropical cyclones.

Corresponding author address: Dr. Chun-Chieh Wu, Dept. of Atmospheric Sciences, National Taiwan University, 61, Ln. 144, Sec. 4, Keelung Rd., Taipei 106, Taiwan. Email: cwu@typhoon.as.ntu.edu.tw

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  • Arakawa, A., and W. H. Schubert, 1974: Interaction of a cumulus cloud ensemble with the large-scale environment, Part I. J. Atmos. Sci., 31 , 674701.

    • Search Google Scholar
    • Export Citation
  • Brand, S., 1970: Interaction of binary tropical cyclones of the western North Pacific Ocean. J. Appl. Meteor., 9 , 433441.

  • Carr III, L. E., and R. L. Elsberry, 1998: Objective diagnosis of binary tropical cyclone interactions for the western North Pacific basin. Mon. Wea. Rev., 126 , 17341740.

    • Search Google Scholar
    • Export Citation
  • Carr III, L. E., M. A. Boother, and R. L. Elsberry, 1997: Observational evidence for alternate modes of track-altering binary tropical cyclone scenarios. Mon. Wea. Rev., 125 , 20942111.

    • Search Google Scholar
    • Export Citation
  • Chan, J. C. L., and W. M. Gray, 1982: Tropical cyclone movement and surrounding flow relationship. Mon. Wea. Rev., 110 , 13541376.

  • Chang, S. W. J., 1983: A numerical study of the interaction between two tropical cyclones. Mon. Wea. Rev., 111 , 18061817.

  • Chang, S. W. J., 1984: Reply. Mon. Wea. Rev., 112 , 16461647.

  • Charney, J. G., 1955: The use of primitive equations of motion in numerical prediction. Tellus, 7 , 2226.

  • Davis, C. A., 1992: Piecewise potential vorticity inversion. J. Atmos. Sci., 49 , 13971411.

  • Davis, C. A., and K. A. Emanuel, 1991: Potential vorticity diagnostics of cyclogenesis. Mon. Wea. Rev., 119 , 19251953.

  • DeMaria, M., and C. L. Chan, 1984: Comments on “A numerical study of the interactions between two tropical cyclones.”. Mon. Wea. Rev., 112 , 16431645.

    • Search Google Scholar
    • Export Citation
  • Dong, K., and C. J. Neumann, 1983: On the relative motion of binary tropical cyclones. Mon. Wea. Rev., 111 , 945953.

  • Fujiwhara, S., 1921: The mutual tendency towards symmetry of motion and its application as a principle in meteorology. Quart. J. Roy. Meteor. Soc., 47 , 287293.

    • Search Google Scholar
    • Export Citation
  • Fujiwhara, S., 1923: On the growth and decay of vortical systems. Quart. J. Roy. Meteor. Soc., 49 , 75104.

  • Fujiwhara, S., 1931: Short note on the behavior of two vortices. Proc. Phys. Math. Soc. Japan. Ser. 3, 13 , 106110.

  • Gryanik, V. M., 1983: Dynamics of singular geostrophic vortices in a two-level model of the atmosphere (or ocean). Bull. Acad. Sci. USSR, Atmos. Oceanic Phys., 19 , 171179.

    • Search Google Scholar
    • Export Citation
  • Holland, G. J., and G. S. Dietachmayer, 1993: On the interaction of tropical-cyclone-scale vortices. III: Continuous barotropic vortices. Quart. J. Roy. Meteor. Soc., 119 , 13811398.

    • Search Google Scholar
    • Export Citation
  • 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 , 877946.

    • Search Google Scholar
    • Export Citation
  • Kuo, H-C., G. T-J. Chen, and C-H. Lin, 2000: Merger of tropical cyclones Zeb and Alex. Mon. Wea. Rev., 128 , 29672975.

  • Lander, M., and G. J. Holland, 1993: On the interaction of tropical-cyclone-scale vortices. I: Observations. Quart. J. Roy. Meteor. Soc., 119 , 13471361.

    • Search Google Scholar
    • Export Citation
  • Liou, C-S., and Coauthors. 1997: The second-generation global forecast system at the Central Weather Bureau in Taiwan. Wea. Forecasting, 12 , 653663.

    • 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
  • Shapiro, L. J., 1996: The motion of Hurricane Gloria: A potential vorticity diagnosis. Mon. Wea. Rev., 124 , 14972508.

  • Shapiro, L. J., and J. L. Franklin, 1999: Potential vorticity asymmetries and tropical cyclone motion. Mon. Wea. Rev., 127 , 124131.

  • Wang, Y., and G. J. Holland, 1995: On the interaction of tropical-cyclone-scale vortices. IV: Baroclinic vortices. Quart. J. Roy. Meteor. Soc., 121 , 95126.

    • Search Google Scholar
    • Export Citation
  • Wu, C-C., and K. A. Emanuel, 1995a: Potential vorticity diagnostics of hurricane movement. Part I: A case study of Hurricane Bob (1991). Mon. Wea. Rev., 123 , 6992.

    • Search Google Scholar
    • Export Citation
  • Wu, C-C., and K. A. Emanuel, 1995b: Potential vorticity diagnostics of hurricane movement. Part II: Tropical storm Ana (1991) and Hurricane Andrew (1992). Mon. Wea. Rev., 123 , 93109.

    • Search Google Scholar
    • Export Citation
  • Wu, C-C., and Y. Kurihara, 1996: A numerical study of the feedback mechanisms of hurricane–environment interaction on hurricane movement from the potential vorticity perspective. J. Atmos. Sci., 53 , 22642282.

    • Search Google Scholar
    • Export Citation
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