Long-term variations of cloud top patterns associated with heavy rainfall over the Korean peninsula

Study region: Korean peninsula Study focus: Although heavy rainfall systems over Korea were known to be characterized by warm-type heavy rainfall associated with a relatively low cloud top, this feature can vary under climate change. This study primarily investigated the mean climatology and linear trends of heavy rainfall and cloud top distributions over the Korean peninsula. The rainy seasons from June to September for the period of 1983-2021 were analyzed in this study. To understand the climatology and changes of heavy rainfall events, thermodynamic variables and synoptic forcings were analyzed. New hydrological insights for the region: Long-term consistent geostationary satellite data provides a unique opportunity to understand the global cloud variations associated with climate change. This study examined the mean climatology and decadal trends of cloud tops inferred from geo-stationary satellite observations, along with heavy rainfall events over the Korean Peninsula. Rainfall and cloud top heights exhibited a decreasing trend in June, whereas an increase in vigorous deep convection was observed in August/September, mainly in southern Korea. The decadal trends in August and September were associated with large-scale circulation changes, while the trend in September was attributed to increasing typhoon visits over the Korean Peninsula. The cloud top changes, with lowered cloud tops in June and elevated cloud tops in August, suggested a shift of deep convective systems toward the late summer over Korea.