Impacts of two types of ENSO on tropical cyclone tracks affecting South Korea: A clustering-based approach

The impacts of different ENSO types on tropical cyclone (TC) tracks affecting South Korea remain less understood, despite extensive studies on their influence on overall western North Pacific (WNP) TC activity. Using a self-organizing map, we classify TC tracks entering the South Korean emergency zone into two clusters. Cluster 1 (C1) TCs form in the Philippine Sea and travel northward. During eastern Pacific La Niña events, a strengthened Walker circulation and a Gill-type response produce southerly wind anomalies along C1 pathway, increasing C1 frequency. Cluster 2 (C2) TCs originate in the southeastern WNP and follow recurving tracks. During central Pacific El Niño events, a Gill-type response induces a cyclonic circulation anomaly over the southeastern WNP, which enhances TC genesis and shifts the subtropical high eastward, increasing C2 frequency. These results reveal distinct dynamic processes through which different ENSO types modulate TC behavior, improving forecast skill for TCs affecting South Korea.