A NUMERICAL STUDY ON THE ABRUPT CHANGE OF VELOCITY OF TROPICAL CYCLONE MOTION

By using the quasi-geostrophic barotropical model. eight numerical experiments whose integration time is longer than five model days are performed in the case of the basic current being zero everywhere. The abrupt decrease of motional velocity of tropical cyclones is exhibited clearly in the model atmosphere, which is closely related with their initial asymmetric structures. The turning northward and then turning eastward of tropical cyclones are also shown, which correspond to their initial irregular structures.