A NUMERICAL STUDY ON THE FORMATION AND DEVELOPMENT OF ISLAND-INDUCED CYCLONE AND ITS IMPACT ON TYPHOON STRUCTURE CHANGE AND MOTION

In this paper,the impact of the Taiwan Island topography on the structure change and motion of Typhoon Dot(9017) during its crossing the Taiwan Island is studied with a modified version of a JMA operational regional model(Japan spectral model,JSM).A series of sensitivity experiments are conducted to detect the forming and developing mechanism of an island-induced cyclone.Results show that lee side low pressure center plays a very important role in the formation of the induced-cyclone while a typhoon is approaching a large island with high mountains.The position and intensity of the induced cyclone is sensitive to the height and location of island mountain,intensity of TC and underlying surface topography distribution as well.A preliminary formation criterion of the island-induced cyclone is obtained.