FACTORS AFFECTING THE TRACK OF TROPICAL CYCLONES AFTER LANDFALL IN EASTERN CHINA

The correlation and composite analyses are carried out in this paper to study major factors affecting the track of tropical cyclones (TCs) after their landfall in Eastern China. The mid-tropospheric environmental steering flow is found to dominate the movement of a TC even after landfall,with the inertia and Coriolis force two other subordinates. A key region is discovered covering the east of China and Yellow Sea,in which the environmental flow significantly affects the movement of TCs making landfall in Eastern China. When the subtropical high in this region strengthens and extends westward,accompanied by northward shrink of the westerly trough,the TC tends to move westward after landfall and disappear inland. However,when the subtropical high in this region weakens and shrinks eastward,accompanied by southward push of the westerly trough,the TC tends to recurve after landfall and re-enter the sea at a location to the north of the site of landfall. The environment before the landfall of a TC has little impact on its post-landfall track,which is sensitive to the environmental change 12～24 hours after landfall. A 6-hour lag is found between the environmental change and the movement of a TC after landfall.