Change of tropical cyclone activity by Pacific‐Japan teleconnection pattern in the western North Pacific

Abstract

This study shows that the Pacific‐Japan (PJ) teleconnection pattern has a significant influence on tropical cyclone (TC) activities over the western North Pacific (WNP) during the boreal summer (July, August, and September). During positive (negative) PJ phase, TCs form at a more northward (southward) location, recurve at a more northeastward (southwestward) location, and frequently pass over the northeast Asian (southeast Asian) region, including Korea and Japan (South China Sea and southern China). In particular, this difference in the TC track between the two phases is observed as a dipole‐like pattern between the regions of Southeast and Northeast Asia. The TC characteristics during the positive PJ phase are caused by the following two stronger atmospheric circulations over the WNP: an anticyclonic circulation centered to the east of Japan and a cyclonic circulation centered to the east of Taiwan. The southeasterly between these two circulations serves as steering flow that TCs move northward toward Korea and Japan from the northeast of the Philippines. Conversely, TCs during the negative PJ phase mainly move westward toward the South China Sea and southern China by the easterly from a stronger anticyclonic circulation centered to the east of Taiwan. As a result of this feature of TC track during the negative PJ phase, TC lifetime is shorter and TC intensity is weaker.