A numerical study of the role of vertical structure of vorticity during tropical cyclone genesis

Venkatesh, TN (2010) A numerical study of the role of vertical structure of vorticity during tropical cyclone genesis. Fluid Dynamics Research, 42 (045506). ISSN 0169-5983

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    Abstract

    An eight-level axisymmetric model with simple parameterizations for clouds and the atmospheric boundary layer was developed to examine the evolution of vortices that are precursors to tropical cyclones. The effect of vertical distributions of the vorticity, especially that arising from a merger of mid-level vortices, has been studied to provide support for a new vortex-merger theory of tropical cyclone genesis. The basic model was validated with the analytical results available for the spin-down of axisymmetric vortices. With the inclusion of the cloud and boundary layer parameterizations, the evolution of deep vortices into hurricanes and the subsequent decay is simulated quite well. Effects of several parameters such as initial vortex strength, radius of maximum winds, sea surface temperature and latitude (Coriolis parameter) on the evolution were examined. A new finding is the manner in which mid-level vortices of the same strength decay and how, on simulated merger of these mid-level vortices, the resulting vortex amplifies to hurricane strength in a realistic time-frame. The importance of the sea-surface temperature on evolution of full vortices has been studied and explained. Also it is found that the strength of the surface vortex determines the time taken by the deep vortex to amplify to hurricane strength.

    Item Type: Journal Article
    Additional Information: This is an author-created, un-copyedited version of an article accepted for publication in [insert name of journal]. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The definitive publisher-authenticated version is available online at http://dx.doi.org/10.1088/0169-5983/42/4/045506
    Uncontrolled Keywords: Tropical cyclone, genesis, balanced vortex model, atmospheric vorticity
    Subjects: ENGINEERING > Fluid Mechanics and Thermodynamics
    GEOSCIENCES > Meteorology and Climatology
    Division/Department: Flosolver Division
    Depositing User: TN Venkatesh
    Date Deposited: 24 Jan 2012 10:02
    Last Modified: 24 Jan 2012 10:02
    URI: http://nal-ir.nal.res.in/id/eprint/10268

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