中文摘要：

涡旋轴对称化是影响热带气旋预报的重要动力学过程．截止目前的研究，均用等值线图形主观识别涡旋轴对称化．本文用一个准地转无幅散的正压涡度方程模式，数值积分48h，模拟了初始非轴对称涡旋演变为轴对称涡旋的轴对称化过程．根据模式输出数据，计算了逐时涡旋外缘线的分形维数DB，用分形维数DB的逐时变化客观表征涡旋轴对称化．在此基础上，计算了分形维数De与热带气旋尺度参数R。和热带气旋强度参数Vmax的相关系数．结果显示，DB与Rm的相关系数为-0．70，DB与Kmax的相关系数为-0．75，相关均显著．用此途径，客观表征了涡旋轴对称化与热带气旋参数的联系．结果在热带气旋预报中有应用前景．

英文摘要：

The vortex axial-symmetrization is an important dynamical process affecting tropical cyclone track change, and it is identified by previous work, up to now, in terms of vorticity fields rather subjectively. Two-dimensional simulations whose integration time is 48 h using a quesi-geostrophic non-divergence barotropic vorticity equation model are performed. The evolutional processes from an initial non-axial-symmetric vortex to the final axial-symmetric vortex are produced, Fractal dimension DR of the perimeter of the vortex is calculated hourly based on the model output data. The results show that fractal dimension can be used to characterize the vortex axial- symmetrization objectively. Based on DB calculated, the correction coefficients CRD and CvD are calculated to be CaD =-0.70 and CVD = -0.75. They each have a significant correction. Here CRD denotes the correction coefficient between DB and Rm being TC scale parameter, and CVD denotes the correction coefficient between DR and Vmax being tropical cyclone intensity parameter. The relation between the vortex axial-symmetrization and the tropical cyclone parameters may be characterized. The results have potential applications in tropical cyclone forecasting.