Impact of Tropical Cyclones on Flash Droughts Over the Korea Peninsula (1980-2020)

Abstract

In a changing climate, climatic extremes are expectedly more common, but interactions between climatic extremes and associated changes in the risk have not well studied. Here, this study aims to investigates the influence of tropical cyclones (TCs) from the western Pacific on droughts over the Korea Peninsula over 1980-2020. First, TC-related daily precipitation are constructed using the ECMWF Reanalysis version 5 (ERA5) hourly precipitation and hourly track information of the center of tropical cyclones. Next, the Effective Drought Index values are computed from precipitation with and without TC-related daily precipitation. The impact of TCs on drought is examined in terms of the drought spatial extent, duration, and intensity. Results show that 1994 is the most beneficial year for drought mitigation (-30% of the spatial extent under extremely drought condition (EDI<-2), -100 days of duration) due to TC landfalls over the Korea Peninsula. The findings of this study suggests the importance of the representation of TCs in climate models on the future drought risk over the Korea Peninsula.