双热带气旋相互作用的机制分析及数值研究 Ⅱ:数值模拟

在本文第Ⅰ部分关于双热带气旋相互作用物卵机制分析的基础上,利用正压原始方程模式对,平面上无大尺度环境流场情况下双热带气旋的相互作用进行了数值模拟研究,重点考察了双热带气旋水平流场相互作用的次级环流机制,文1]中所提出的双热带气旋相互作用的临界距离效应概念在模式中得到了验证.同时通过模拟还发现,双热带气旋的联合强度越强、中心间距越小,则互旋越快;对于相互吸引的双热带气旋而言,合并后范围有所扩大,强度有一定的加强,并且较强的两个热带气旋比一强一弱的两个热带气旋维持的时间要长、较难于合并.这些结果与实际双热带气旋相互作用的观测事实极为一致.

Mechanism Analysis and Numerical Studyon the Interactions of Binary Tropical CyclonesPart II:Numerical Simulation

Based on the mechanism analysis of the interactions of binary tropical cyclones in Part I of this study, the numerical study, of the interactions between two tropical cyclones without environmental flow on an f-plane has been carried out using a barotropic primitive equation model. The secomdary circulation mechanism of the horirontal flow interactions of binary tropical chclones has been examined in detail and the conception of critical separation distance (CSD) effect proposed in Part I has been verified by modeling. In addition, from the numerical experiments it is found that the stronger the combined strength of binary system and the less the separation distance, the faster the two tropical cyclones rotate cyclonically around each other and that for two attracting tropical cyclones, the horizontal size becomes larger and intensity increases after they merge into one system and also two strong tropical cyclones have a longer duration and are more difficult to merge than one strong and one weak do. These results are in agreement with the observations of binary tropical cyclones in the real atmosphere.