ISSN 1006-8775CN 44-1409/P

Analytic Study on Potential Instability and Spiral Structure of Rain Clusters


  • This paper presents a study on potential instability and spiral structure of unstable rain clusters. First, we develop a linearized non-axisymmetrical mathematic model for rain clusters in circular cylindrical coordinates and acquire its analytic solution. Second, we discuss the potential instability of non-axisymmetrical rain clusters. Finally, we conclude that spiral structures can exist in rain clusters. Our analysis indicates that potential instability occurs when humid stratification coefficient is less than zero. Unstable growth rate increases with the increase of the absolute value for humid stratification coefficient. The simpler the vertical structure of perturbation, the thicker the inversion layer; additionally, the smaller the radius of the rain clusters, the larger the unstable growth rate. Simulation results agree well with those from observation and forecast. The spiral structure simulated by our model is similar to a radar echo, suggesting that rain clusters with spiral structures can occur in the atmosphere. In addition, they are generally close to the model solution in this work.
  • [1]
    WU Qing-li, CHEN Min, WANG Hong-qing, et al. Thenumerical simulation on meso-βscale flow structure nrain-cluster [J]. Chin. Sci. Bull., 2002, 47(18): 1 437-1 441.
    [2]
    ZENG Qing-cun. The mathematical physics foundation ofnumerical weather prediction [M]. Beijing: Science Press, 1979:425.
    [3]
    GAO Shou-ting, SUN Shu-qing. Applying Richardsonnumber to distinguish the instability of mesoscale wave [J].Chin. J. Atmos. Sci., 1986, 10(2): 171-182.
    [4]
    ZHANG Ming, ZHANG Li-feng, AN Jie. Atmosphericwave spectra analysis and instability, I: The perturbation intwo-dimension rotational-stratification [M]. Beijing: ChinaMeteorological Press, 2008: 166pp.
    [5]
    ZHENG Xian-zhao, SHOU Shao-wen, SHEN Xin-yong.Physics parameters analysis of a heavy rainfall event [J].Meteor. Mon., 2006, 32(1): 102-106.
    [6]
    TAN Yan-yan. A study on potential instability in rainmass-scale [D]. M.S. degree thesis of PLA Univ. of Sci. Eng.,2007, 7-28.
    [7]
    ZHANG Ming, HUANG Si-xun. The non-dispersionsolution of nonlinear spiral planetary wave [J]. Acta Meteor.Sinica, 1987, 45(1): 30-38.
    [8]
    ZHANG Ming. Research on instability problem ofbarotropic vortex [J]. Chin. J. Atmos. Sci., 1995, 19(6):677-686.
    [9]
    HUANG Hong, ZHANG Ming. Study on destabilization ofspiral wave in barotropic vortex [J]. J. Trop. Meteor., 2003,19(2): 197-202.
    [10]
    LIANG Dan-qing, ZHANG Ming. The spiral waveinstability in vortex of two-layer barotropic fluid [J]. J. Trop.Meteor., 2003, 19(4): 405-412.
    [11]
    LIU Xiao-ran, LI Guo-ping. Review and prospect ofresearch on the Tibetan plateau vortex [J]. Arid Meteor., 2006,24(1): 60-66.
    [12]
    YU Shu-hua. New research advances of the TibetanPlateau vortex in summer [J]. Torrential Rain Disas., 2008,27(4): 367-372.
    [13]
    MONTGOMERY M T, ENAGONIO J. Tropical cyclonevia convectively forced vortex Rossby-wave in athree-dimensional quasi-geostrophic model [J]. J. Atmos. Sci. ,1998, 55(20): 3 176-3 207.
    [14]
    LUO De-hai. Planetary-scale baroclinic envelope Rossbysolitons in a two-layer model and their interaction withsynoptic-scale eddies [J]. Dyn. Atmos. Oceans, 2000, 32(1):27-74.
    [15]
    HUANG Hong, ZHANG Ming. Unstable dynamicalproperties of spiral bands in tropical cyclones [J]. Acta Meteor.Sinica, 2008. 66(1): 81-89.
    [16]
    MONTGOMERY M T, KALLENBACH R J. A theory ofvortex Rossby-wave and its application to spiral bands andintensity changes in hurricanes [J]. Quart. J. Roy. Meteor. Soc.,1997, 123: 435-465.
    [17]
    MOLINARI J. VOLLARO S. Potential vorticity analysisof tropical cyclone intensification [J]. J. Atmos. Sci., 1998,55(16): 2 632-2 644.
    [18]
    AN Jie. A study about the instability in rainstorm [J]. M.S.degree thesis of PLA Univ. of Sci. Eng., 2004, 13-21.

Get Citation

YU Jie, ZHANG Ming. Analytic Study on Potential Instability and Spiral Structure of Rain Clusters[J]. Journal of Tropical Meteorology, 2011, 17(1): 79-86.
YU Jie, ZHANG Ming. Analytic Study on Potential Instability and Spiral Structure of Rain Clusters[J]. Journal of Tropical Meteorology, 2011, 17(1): 79-86.
Export:  

Share Article

Article Metrics

Article views:1626 Times PDF downloads:1109 Times Cited by: Times

Manuscript History

Catalog

    /

    DownLoad:  Full-Size Img  PowerPoint
    Return
    Return