Cluster analysis of tropical cyclone tracks around Korea and its climatological properties

After the fuzzy clustering method (FCM) that analyzes the tracks of the tropical cyclones (TCs) struck the Korean peninsula (hereafter, K-TC) for a 60-year period (1951?C2010), it is found that both frequency and intensity of K-TC have been increased in recent years. In the order of the cluster number, both K-TC track pattern and its full-track pattern tended to shift southward. That is, while the passage frequency of TC in mainland China and the Manchurian regions decreased, it instead over the sea. Due to this decrease in the topographic effect on TC before reaching Korea, TC intensity around Korea became stronger. The vertical wind shear well reflected a TC intensity around Korea, which became weaker in mid-latitudes of East Asia. On the other hand, the peak month of K-TC frequency lags in the order of the cluster number. The two clusters that most TCs pass through the Korean Peninsula showed a stronger intensity and higher frequency before the 1970s. Meanwhile, another two clusters that most TCs pass through the Straits of Korea or the western region of the Japanese Islands showed those characteristics from the 1980s onward. Consequently, the changes in TC track, recurvature, frequency, and intensity around Korea were related to the southward shift of the western North Pacific high in the order of the cluster number.