Impacts of Climate Change on Tropical Cyclones and associated Rainfall over South Korea: Storyline and Risk-based approaches

The western North Pacific region has experienced Tropical Cyclones (TCs)-caused damages, including the heavy rainfall disaster brought by Typhoon Hinnamnor (2022) in South Korea. The future changes in the intensity and frequency of such a Violent Typhoon and its associated rainfall are global concern. This study adopted the storyline approach using the Pseudo-Global Warming (PGW) method to quantify the impact of climate change on Typhoon Hinnamnor and its associated rainfall. Furthermore, we employed the risk-based approach to examine the changes in frequency and intensity of TCs affecting South Korea. Our storyline approach showed the increase of maximum sustained wind speed by 15 %, the decrease of minimum sea level pressure by 2 %, and the increase of basin-average rainfall by 29.4 % over the Nakdonggang basin in the PGW experiment considering the 2090s SST condition under the SSP2–4.5 scenario in the Typhoon Hinnamnor simulation. Our risk-based approach examining the identified TCs in large ensemble climate dataset found that the maximum sustained wind speed increased by 14 % for Violent Typhoons under +4 K climate, while the minimum sea level pressure decreased by 1 %. Overall, the identified changes in the TC intensity were comparable between the storyline and risk-based approaches, highlighting the robustness of our findings. Furthermore, we analyzed the changes in frequency of TCs affecting South Korea under climate change in the risk-based approach. While we found a decrease (−36 %) in frequency of all category TCs affecting South Korea, the frequency of Violent Typhoons increased (+27 %) under the 4 K warming climate. This study provides useful insights on the TC and its rainfall changes under climate change, which can be incorporated in the regional disaster risk assessment. • Impact assessment of climate change based on storyline and risk-based approaches. • Storyline: Pseudo Global Warming simulation on Typhoon Hinnamnor (2022). • Risk-based: Large ensemble climate dataset (d4PDF)-based analysis. • Increases in TC intensity were comparable between the storyline and risk-based approaches. • Frequency of all TCs dropped by 36 %, but Violent Typhoons rose by 27 % under +4 K warming.