Effects of the Pacific-Japan teleconnection pattern on tropical cyclone activity and extreme precipitation events over the Korean peninsula

In this study, an exploratory analysis was carried out to gain a better understanding of the potential impacts of the two phases (negative and positive) of the Pacific-Japan (PJ) pattern on tropical cyclone (TC) activity affecting the Korean Peninsula (KP) and TC-induced extreme precipitation events over five major river basins in Korea. The results show that large-scale atmospheric environments during the years in the positive PJ phase (referred to as positive PJ years) are more favorable for TC activity than those during the years in the negative PJ phase (referred to as negative PJ years). It is found that wind shear is weaker, rising motion is stronger, and relative humidity is higher over the KP in positive PJ years than in negative PJ years. TCs affecting the KP during positive (negative) PJ years tend to occur more to the southwest (northeast), recurve at locations more to the northwest (northeast), and show an increase (decrease) in frequency over Korea and Japan. As a result, TCs making landfall are found more often over southeastern South Korea during positive PJ years. Despite the relatively modest sample size used in this study, we expect that the results described herein will be useful in developing a critical support system for the effective reduction and mitigation of TC-caused disasters as well as for water supply management in coupled human and natural systems.