热带气旋路径偏折内在原因的动力分析

THE DYNAMICAL RESEARCH OF TC STRUCTURE ON TRACK DEPARTURE

视热带气旋(以下简称TC)为半径等于R的圆形涡旋,对其水平运动方程作整个TC区域的平均,进而得到TC的移动方程。同时,视TC的移动轨迹为一特征弧线,导出了TC移动路径的曲率方程,并对TC的结构及其变化所引起的TC路径偏折规律进行了讨论。结果表明,TC的尺度大小、最大风速及其半径等的变化均能导致路径的偏折,此外,TC的非对称结构也是路径偏折的重要原因。

Taking the tropical cyclone (TC) as a circular vortex with radius R, horizontal motion equations are averaged over the whole TC area to get its movement with non-friction, weak environment. And viewing the TC track as some cambers, we obtain the curvature equation, for discussion of the deviation law effect of the TC structure on track. The results show that TC's scale, maximal velocity and its radius, and their change etc. make TC track deviate, and the TC asymmetry structure also brings the departure to the track. Only more than 2 wave number asymmetry structure can take the departure but the dipole structure (wave number is 1) can't make TC track departure.