Impact of Extreme Pacific-Japan Teleconnection Patterns on Tropical Cyclone Activity around Far East Asia

Abstract

This study identified the relationship between tropical cyclone (TC) activity and extreme Pacific-Japan (PJ) teleconnection patterns in August and September. In the East China Sea (ECS) and Mariana Islands (MI) regions, where the edge of the western North Pacific subtropical high (WNPSH) is located, approximately 60%-75% of TCs migrate to Far East Asian countries. A significant positive correlation existed between the frequency of northward migration of TCs and PJ patterns, since the TC frequency in the ECS and MI regions was significantly higher in the positive compared with the negative phase. In the positive phase, the main reason for the large number of TCs occurring was the monsoon trough's location and strength. The strong and northeastward-shifted monsoon trough in the positive phase leads to more TCs in the ECS and MI regions. Other large-scale environments associated with TC formation also favored TC genesis around the ECS and MI regions. The higher PDI (power dissipation index) during the positive PJ phase can potentially lead to significant impacts in the Far East Asian countries. These characteristics were particularly more notable in August compared with September.