摘要
ＰＥＲＳＰＥＣＴＩＶＥＳＯＦＴＲＯＰＩＣＡＬＣＹＣＬＯＮＥＵＮＵＳＵＡＬＭＯＴＩＯＮＳ──ＴＨＥＤＩＦＦＩＣＵＬＴＩＥＳＩＮＣＵＲＲＥＮＴＴＲＯＰＩＣＡＬＣＹＣＬＯＮＥＦＯＲＥＣＡＳＴＩＮＧＣｈｅｎＬｉａｎｓｈｏｕ（陈联寿）ＣｈｉｎｅｓｅＡｃａｄｅｍ...
Abstract By unusual motion of a tropical cyclone (TC), it refers to the large deviation of a TC track from the ini-tial environmental steering flow. Quite often , the deviation results from a sudden change either in direction orin velocity. Such unusual motion is one of the difficulties in TC operational track forecasting. For the timebeing, the current available numerical models and other objective prediction techniques seem to be quite inad-equate in predicting such unusual events.The causes of TC unusual motion have multiple factors, and it is believed that the inner asymmetricstructure of a TC is one of the major factors that leads to such a behaviour. Moreover, the interactions be-tween circulation systems in different motion scales as well as the impacts of underlying surfaces are amongthe other factors that can not be neglected. This paper intends to discuss the aforementioned causes that giverise to TC unusual motions.It is of the author’s opinion that the TC unusual motion forecasts will see a remarkable improvement ifdue consideration is given to the physical processes related with the above causes in numerical models.
