台风移动规律的研究 Ⅲ.台风与外界水平动量交换的影响

A STUDY ON TYPHOON MOVEMENT Ⅲ. EFFECT OF THE HORIZONTAL MOMENTUM EXCHANGE BETWEEN TYPHOONS AND ENVIRONMENT

关键词:  台风移动  水平动量交换  半非对称台风

Key words:  Typhoon movement  Horizontal momentum exchange  Semi-asymmetric typhoon

摘要:

着重分析了流场半非对称台风的流入层和流出层与外界的水平动量交换影响台风移动的定性特征。结果表明,主要流入通道或主要流出通道位于台风右(左)侧时,有利于台风加速、左折(减速、右折);当主要流入通道或主要流出通道位于台风后部(前部)时,有利于台风加速、右折(减速、左折)。

Abstract:

Two semi-asymmetric flow patterns of typhoons are chosen to qualitatively determine the effect of exchange of horizontal momentum between inflow and outflow layers on the motion of typhoons. The results show that only the asymmetric flow component (residual after azimuthal mean flow has been removed) could cause a net momentum input into or output from a typhoon and therefore contribute to the changes in speed and direction of the typhoon movements. A typhoon with major inflow and/or outflow channels on its right (left) side would tend to accelerate and turn left (decelerate and turn right); On the other hand, a typhoon with major inflow and/or outflow channels in the front (rear) semi-circle would tend to accelerate and turn right (decelerate and turn left).